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  • 1.
    Abdel–Khalik, Jonas
    et al.
    Institute of Mass Spectrometry, College of Medicine, Swansea University.
    Björklund, Erland
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Plattformen för molekylär analys. Kristianstad University, Faculty of Natural Science, Avdelningen för miljö- och biovetenskap. Kristianstad University, Faculty of Natural Science, Research environment MoLab.
    Hansen, Martin
    Department of Civil & Environmental Engineering, Stanford University.
    Simultaneous determination of endogenous steroid hormones in human and animal plasma and serum by liquid or gas chromatography coupled to tandem mass spectrometry2013In: Journal of chromatography. B, ISSN 1570-0232, E-ISSN 1873-376X, Vol. 928, no June, p. 59-77Article in journal (Refereed)
    Abstract [en]

    Analytical methodologies based on liquid or gas chromatography coupled to tandem mass spectrometry for the simultaneous determination of two or more endogenous steroid hormones in human and animal plasma and serum has received increased attention the last few years. Especially in the clinical setting steroid profiling is of major importance in disease diagnostics. This paper discusses recent findings in such multi-steroid hormone procedures published from 2001 to 2012. The aim was to elucidate possible relationships between chosen analytical technique and the obtained analyte sensitivity for endogenous steroid hormones. By evaluating the success, at which the currently applied techniques have been utilized, more general knowledge on the field is provided. Furthermore the evaluation provides directions in which future studies may be interesting to conduct.

  • 2.
    Abdel-Khalik, Jonas
    et al.
    England.
    Björklund, Erland
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Plattformen för molekylär analys. Kristianstad University, Faculty of Natural Science, Avdelningen för miljö- och biovetenskap. Kristianstad University, Faculty of Natural Science, Research environment MoLab.
    Nielsen, Frederik Knud
    Danmark.
    Hansen, Martin
    Danmark.
    Incorporation of (14)C-cholesterol in human adrenal corticocarcinoma H295R cell line and online-radiodetection of produced (14)C-steroid hormone metabolites2017In: Journal of Pharmaceutical and Biomedical Analysis, ISSN 0731-7085, E-ISSN 1873-264X, Vol. 145, p. 569-575Article in journal (Refereed)
    Abstract [en]

    This study demonstrates the addition of (14)C-cholesterol to the human cell line H295R will in-situ form radiolabeled steroid hormones allowing for new mechanistic and metabolic insights. The aim of the present study was to in-situ radiolabel steroid hormones from cell line-incorporated (14)C-cholesterol using the OECD guideline 456, H295R steroidogenesis in-vitro assay. Radiodetection of the steroid metabolites of the steroidogenic pathway allows for an improved understanding of the various enzymatic mechanisms involved without necessarily being dependent on quantification. Generated radiolabeled steroids were analyzed using HPLC hyphenated with a Flow Scintillation Analyzer (FSA). H295R cells were incubated with radiolabeled cholesterol and cell media were collected and prepared by solid phase extraction and analyzed with HPLC-FSA. For successful radiolabeling of the steroids in the steroidogenesis of H295R cells, radioactive cholesterol may potentially only need to be added just before the cells are incubated for 72h in well plates. Based on the obtained HPLC-FSA chromatograms, and confirmation of the observations by studies in the literature, a qualitative time profile for the production of steroid hormones was estimated. Multiple radiolabeled steroid hormones were identified by means of analytical standards and UV (ultraviolet) co-chromatography, though the elucidation of multiple metabolites remains unresolved. Although online radiodetection proved to suffer from suboptimal sensitivity, the concept of radiolabeling the steroidogenesis in H295R cells with (14)C-cholesterol and detecting the radiolabeled steroid hormones online was proved and may assist in further toxicological studies.

  • 3.
    Abegão, Daniel
    et al.
    Lunds universitet.
    Roger, Kevin
    Laboratoire de Physique et Mécanique des Milieux Hétérogènes & Laboratoire de Colloïdes et Matériaux Divisés, ESPCI, Paris.
    Holdaway, James
    Lunds universitet.
    Nilsson, Lars
    Lunds universitet.
    Vernhet, Aude
    Campus SupAgro-INRA, Frankrike.
    Olsson, Viktoria
    Kristianstad University, School of Education and Environment, Avdelningen för Praktisk-estetiska ämnen. Kristianstad University, Forskningsmiljön Food and Meals in Everyday Life (MEAL).
    Cabane, Bernard
    Laboratoire PMMH, CNRS-ESPCI, Frankrike.
    Schillén, Karin
    Lunds universitet.
    Nylander, Tommy
    Lunds universitet.
    Characterization of three tanninic samples: an approach to the tannin-tannin and protein-tannin colloidal interactions2014Conference paper (Other academic)
  • 4.
    Aghi, Nawar
    et al.
    Kristianstad University, Faculty of Natural Science.
    Abdulal, Ahmad
    Kristianstad University, Faculty of Natural Science.
    House Price Prediction2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study proposes a performance comparison between machine learning regression algorithms and Artificial Neural Network (ANN). The regression algorithms used in this study are Multiple linear, Least Absolute Selection Operator (Lasso), Ridge, Random Forest. Moreover, this study attempts to analyse the correlation between variables to determine the most important factors that affect house prices in Malmö, Sweden. There are two datasets used in this study which called public and local. They contain house prices from Ames, Iowa, United States and Malmö, Sweden, respectively.The accuracy of the prediction is evaluated by checking the root square and root mean square error scores of the training model. The test is performed after applying the required pre-processing methods and splitting the data into two parts. However, one part will be used in the training and the other in the test phase. We have also presented a binning strategy that improved the accuracy of the models.This thesis attempts to show that Lasso gives the best score among other algorithms when using the public dataset in training. The correlation graphs show the variables' level of dependency. In addition, the empirical results show that crime, deposit, lending, and repo rates influence the house prices negatively. Where inflation, year, and unemployment rate impact the house prices positively.

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  • 5.
    Ahlerup, Amanda
    Kristianstad University, Faculty of Natural Science.
    Naturen, kulturen och helheten: En studie i hur kulturreservatens informationstexter skildrar samspelet mellan natur och kultur i landskapet2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Den europeiska landskapskonventionen belyser att landskapet skapas genom påverkan av och i samspel mellan naturliga processer och mänsklig kultur. Konventionen har bidragit till en medvetenhet kring vikten av att uppmärksamma detta samspel och behovet av en integrerad natur- och kulturmiljövård. Kulturreservaten knyter genom sin intention att förmedla natur- och kulturhistoriska helheter an till landskapskonventionen. Syftet med denna studie är att undersöka i vilken utsträckning kulturreservatens informationstexter skildrar samspelet mellan naturelement och kulturelement i landskapet. Informationstexter i nio kulturreservat har analyserats genom en innehållsanalys där förekomsten av fristående naturelement och kulturelement samt samspel mellan naturelement och kulturelement har kvantifierats. Resultatet visar att skildringar av samspel förekommer i 60% av reservatens informationstexter. Detta indikerar att uppdelningen av skyddsvärda områden i natur- och kulturreservat möjligen är obefogad då landskapet inte låter sig indelas i natur och kultur. 

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  • 6.
    Ahlm, Isabelle
    et al.
    Kristianstad University College.
    Johansson, Åsa
    Kristianstad University College.
    Toftaholms utmark: en inventering av natur- och kulturvärden två år efter stormen Gudrun2008In: Tsunami, ISSN 1651-5803, no 2Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    I samband med stormen Gudrun 2005 föll 70-75 miljoner m³ skog i Sverige. Många människor drabbades hårt ekonomiskt och känslomässigt, men finns det inte också något positivt i tragiken? Vilka fördelar skulle kunna uppstå ur denna omfattande och omskakande händelse i skogssverige? Rapporten om Toftaholms utmark syftar till att synliggöra de natur- och kulturvärden som bildats eller fått möjlighet att framlyftas tack vare stormen. En undersökning har gjorts av vilka naturvärden som uppkom i Toftaholmsområdet samt hur de skiljer sig åt mellan Natura 2000-området och produktionsskogen intill. ”Följde” Gudrun de rekommendationer som finns för skogsvård angående naturvärden? Många kulturvärden har varit gömda i hektar av granskog. Då stormen skapade fält av rotvältor framträder dessa kulturhistoriska skatter tydligare. När de stormfällda ytorna nu återplanteras finns risken att de åter faller i glömska. Vad kan vi göra för att dessa värden inte ska döljas och kanske gå förlorade? Finns det möjlighet att efter stormen sammanföra och kombinera olika intressen så som natur- kultur- och ekonomi, och på så sätt bevara flera av landskapets värden?

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  • 7.
    Ahlzén, Karl Fredrik
    Kristianstad University, School of Education and Environment.
    Kan problemen vara lösningen?: en studie om elevers olikheter i metoden att lösa ett bestämt matematiskt problem i årskurs 9.2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Uppsatsen är främst skriven till grundskolelärare för årskurs 6-9 i matematik. Uppsatsen behandlar rika matematiska problem och niondeklassares olika strategier och representationer som eleverna uppvisar för att lösa rika matematiska problem.

    Bakgrunden till uppsatsen grundar sig på mitt eget stora intresse för att undervisning skall vara utformad för att se och bemöta elevers olikheter som något positivt. Undervisning där man ser och utgår ifrån elevers olikheter och erfarenheter gör att elever kommer att vara olika djupt och långt i kursen. Här är det viktigt för läraren att vara uppmärksam och stötta alla elever, så att ingen kommer efter i lärandet. Att göra undervisningen mer personlig och meningsfull kan vara ett steg i riktning mot att höja intresset för matematik men kommer givetvis krävas mera av läraren.

    I teoridelen redogörs delar av rika matematiska problem och dess historia. Vidare tar jag upp vikten av att se till den enskilda individen och dess förutsättningar, samt olika möjligheter till att möta den enskilda individen i matematikundervisningen.

    Det empiriska materialet hanteras anonymt för att garantera anonymitet. Problemen löstes av samtliga elever i årskurs 9 på en skola i södra Sverige. Resultatet visade att det förekommer olika representationer för hur elever tänker kring ett bestämt problem. Att nivågrupperingar skulle vara att föredra kan inte bekräftas ur resultatet. Resultatet visade att den blandade gruppen hade en djupare förståelse totalt sett.

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  • 8.
    Ahlén, Ingemar
    et al.
    SLU.
    Angelstam, Per
    SLU.
    Bensch, Staffan
    Lunds universitet.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Enemar, Anders
    Göteborgs universitet.
    Fagerström,, Torbjörn
    SLU.
    Green, Martin
    Lunds universitet.
    Gustafsson, Lars
    Uppsala universitet.
    Gustafsson, Lena
    SLU.
    Mikael, Hake
    SLU.
    Dennis, Hasselquist,
    Lunds universitet.
    Hedenström, Anders
    Lunds universitet.
    H-Lindgren, Christina
    Umeå universitet.
    Lindberg, Peter
    Göteborgs universitet.
    Lindström, Åke
    Lunds universitet.
    Michanek, Gabriel
    Luleå tekniska universitet.
    Nilsson, Leif
    Lunds universitet.
    Nilsson, Sven G
    Lunds universitet.
    Pärt, Tomas
    SLU.
    Sundberg, Jan
    Uppsala universitet.
    Svensson, Sören
    Lunds universitet.
    Tjernberg, Martin
    SLU.
    Ulfstrand, Staffan
    Uppsala universitet.
    Brusewitz, Gunnar
    Stockholms universitet.
    Edman, Stefan
    Chalmers tekniska högskola.
    Jonsson, Lars
    Uppsala universitet.
    Landell, Nils-Erik
    Wahlstedt, Jens
    Emanuelsson, Urban
    Centrum för biologisk mångfald.
    Ingelög, Torleif
    Artdatabanken.
    Karlsson, Mikael
    Svenska naturskyddsföreningen.
    Kristoferson, Lars
    WWF.
    Lindell, Lars
    Sveriges Ornitologiska Förening.
    Nya järnvägen hotar unikt naturområde2002In: Aftonbladet, ISSN 1103-9000Article in journal (Other (popular science, discussion, etc.))
  • 9.
    Airey, John
    et al.
    Uppsala Universitet.
    Eriksson, Urban
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Learning in Science and Mathematics (LISMA).
    A semiotic analysis of the disciplinary affordances of the Hertzsprung-Russell diagram in astronomy2014Conference paper (Refereed)
    Abstract [en]

    One of the central characteristics of disciplines is that they create their own particular ways of knowing the world. This process is facilitated by the specialization and refinement of disciplinary-specific semiotic resources over time. Nowhere is this truer than in the sciences, where it is the norm that disciplinary-specific representations have been introduced and then refined by a number of different actors. As a consequence, many of the semiotic resources used in the sciences today still retain some traces of their historical roots.

    In this paper we analyse one such disciplinary-specific semiotic resource from the field of Astronomy—the Hertzsprung-Russell diagram. We audit the potential of this semiotic resource to provide access to disciplinary knowledge—what Fredlund et al (2012) have termed its disciplinary affordances. Our analysis includes consideration of the use of scales, labels, symbols, sizes and colour. We show how, for historical reasons, the use of these aspects in the resource may differ from what might be expected by a newcomer to the discipline.

    We suggest that some of the issues we highlight in our analysis may, in fact, be contributors to alternative conceptions and therefore propose that lecturers pay particular attention to the disambiguation of these features for their students.

  • 10.
    Airey, John
    et al.
    Stockholm Universitet.
    Eriksson, Urban
    Kristianstad University, Faculty of Education, Research environment Learning in Science and Mathematics (LISMA). Kristianstad University, Faculty of Education, Avdelningen för matematik- och naturvetenskapernas didaktik. Nationellt resurscentrum för fysik, Lunds universitet.
    Unpacking the Hertzsprung-Russell diagram: a social semiotic analysis of the disciplinary and pedagogical affordances of a central resource in astronomy2019In: Designs for Learning, ISSN 1654-7608, Vol. 11, no 1, p. 99-107Article in journal (Refereed)
    Abstract [en]

    In this paper we are interested in the relationship between disciplinary knowledge and its representation. We carry out a social semiotic analysis of a central tool used in astronomy—the Hertzsprung-Russell (H-R) diagram—in order to highlight its disciplinary and pedagogical affordances. By analysing the relationship between disciplinary knowledge and its representation in this way we claim that it becomes possible to identify potential barriers to student learning—instances where semiotic resources with high disciplinary affordance have low pedagogical affordance for newcomers to the discipline. The astronomy resource that we have chosen to analyse has played a pivotal role in our understanding of stellar evolution and as such it features prominently on all undergraduate astronomy programs. However, like most disciplinary-specific semiotic resources, today’s H-R diagram is the culmination of many years of work by numerous disciplinary experts. Over time, the H-R diagram has been revised and reworked by a number of different actors in order to reconcile it with developing observational and theoretical advances. As a consequence, the H-R diagram that we know today combines many layers of astronomical knowledge, whilst still retaining some rather quirky traces of its historical roots. In this paper we adopt a social semiotic lens to analyse these ‘layers of knowledge’ and ‘historical anomalies’ showing how they have resulted in a number of counterintuitive aspects within the diagram that have successively lowered its pedagogical affordance. We claim that the counterintuitive aspects we identify in our analysis give rise to potential barriers to student disciplinary learning. Using our analysis as a case study, we generalise our findings suggesting four types of barrier to understanding that are potentially at work when meeting disciplinary-specific semiotic resources for the first time. We finish the paper by making some general suggestions about the wider use of our analysis method and ways of dealing with any barriers to learning identified. In the specific case of the H-R diagram, we suggest that lecturers should explicitly tease out its disciplinary affordances by the use of ‘unpacked’ resources that have a higher pedagogical affordance. 

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  • 11.
    Airey, John
    et al.
    Uppsala universitet.
    Eriksson, Urban
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Learning in Science and Mathematics (LISMA).
    What do you see here?: using an analysis of the Hertzsprung-Russell diagram in astronomy to create a survey of disciplinary discernment2014In: Book of abstracts: The First Conference of the International Association for Cognitive Semiotics(IACS-2014), September 25-27, 2014 Lund University, 2014, p. 52-53Conference paper (Refereed)
    Abstract [en]

    Becoming part of a discipline involves learning to interpret and use a range of disciplinary-specific semiotic resources (Airey, 2009). These resources have been developed and assigned particular specialist meanings over time. Nowhere is this truer than in the sciences, where it is the norm that disciplinary-specific representations have been introduced and then refined by a number of different actors in order to reconcile them with subsequent empirical and theoretical advances. As a consequence, many of the semiotic resources used in the sciences today still retain some (potentially confusing) traces of their historical roots. However, it has been repeatedly shown that university lecturers underestimate the challenges such disciplinary specific semiotic resources may present to undergraduates (Northedge, 2002; Tobias, 1986).

    In this paper we analyse one such disciplinary-specific semiotic resource from the field of Astronomy—the Hertzsprung-Russell diagram. First, we audit the potential of this semiotic resource to provide access to disciplinary knowledge—what Fredlund et al (2012) have termed its disciplinary affordances. Our analysis includes consideration of the use of scales, labels, symbols, sizes and colour. We show how, for historical reasons, the use of these aspects in the resource may differ from what might be expected by a newcomer to the discipline. Using the results of our analysis we then created an online questionnaire to probe what is discerned (Eriksson, Linder, Airey, & Redfors, in press) with respect to each of these aspects by astronomers and physicists ranging from first year undergraduates to university professors.

    Our findings suggest that some of the issues we highlight in our analysis may, in fact, be contributors to the alternative conceptions of undergraduate students and we therefore propose that lecturers pay particular attention to the disambiguation of these features for their students.

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  • 12.
    Airey, John
    et al.
    Uppsala universitet.
    Eriksson, Urban
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Learning in Science and Mathematics (LISMA).
    Fredlund, Tobias
    Uppsala universitet.
    Linder, Cedric
    Uppsala universitet.
    On the disciplinary affordances of semiotic resources2014In: Book of abstracts: The First Conference of the International Association for Cognitive Semiotics(IACS-2014), September 25-27, 2014 Lund University, 2014, p. 54-55Conference paper (Refereed)
    Abstract [en]

    In the late 70’s Gibson (1979) introduced the concept of affordance. Initially framed around the needs of an organism in its environment, over the years the term has been appropriated and debated at length by a number of researchers in various fields. Most famous, perhaps is the disagreement between Gibson and Norman (1988) about whether affordances are inherent properties of objects or are only present when they are perceived by an organism. More recently, affordance has been drawn on in the educational arena, particularly with respect to multimodality (see Linder (2013) for a recent example). Here, Kress et al. (2001) have claimed that different modes have different specialized affordances. Then, building on this idea, Airey and Linder (2009) suggested that there is a critical constellation of modes that students need to achieve fluency in before they can experience a concept in an appropriate disciplinary manner. Later, Airey (2009) nuanced this claim, shifting the focus from the modes themselves to a critical constellation of semiotic resources, thus acknowledging that different semiotic resources within a mode often have different affordances (e.g. two or more diagrams may form the critical constellation).

    In this theoretical paper the concept of disciplinary affordance (Fredlund et al., 2012) is suggested as a useful analytical tool for use in education. The concept makes a radical break with the views of both Gibson and Norman in that rather than focusing on the discernment of one individual, it refers to the disciplinary community as a whole. Put simply, the disciplinary affordances of a given semiotic resource are determined by those functions that the resource is expected to fulfil by the disciplinary community. Disciplinary affordances have thus been negotiated and developed within the discipline over time. As such, the question of whether these affordances are inherent or discerned becomes moot. Rather, from an educational perspective the issue is whether the meaning that a semiotic resource affords to an individual matches the disciplinary affordance assigned by the community. The power of the term for educational work is that learning can now be framed as coming to discern the disciplinary affordances of semiotic resources.

    In this paper we will briefly discuss the history of the term affordance, define the term disciplinary affordance and illustrate its usefulness in a number of educational settings.

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  • 13.
    Alagic, Amir
    Kristianstad University College, School of Engineering.
    BookZone web shop2007Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [en]

    My task was to create an e-commerce solution or web shop that is integrated with PayPal system. The intent of this paper is to show how this e-commerce web application was built and integrated with the PayPal system.

    The underlying technology used in the implementation of the application includes .Net 2.0 framework (ASP.Net 2.0 and C# 2005 and Express edition of SQL Server 2005)

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  • 14.
    Alassadi, Abdulrahman
    et al.
    Kristianstad University, Faculty of Natural Science.
    Ivanauskas, Tadas
    Kristianstad University, Faculty of Natural Science.
    Classification Performance Between Machine Learning and Traditional Programming in Java2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study proposes a performance comparison between two Java applications with two different programming approaches, machine learning, and traditional programming. A case where both machine learning and traditional programming can be applied is a classification problem with numeric values. The data is heart disease dataset since heart disease is the leading cause of death in the USA. Performance analysis of both applications is carried to state the differences in four main points; the development time for each application, code complexity, and time complexity of the implemented algorithms, the classification accuracy results, and the resource consumption of each application. The machine learning Java application is built with the help of WEKA library and using its NaiveBayes class to build the model and evaluate its accuracy. While the traditional programming Java application is built with the help of a cardiologist as an expert in the field of the problem to identify the injury indications values. The findings of this study are that the traditional programming application scored better performance results in development time, code complexity, and resource consumption. It scored a classification accuracy of 80.2% while the Naive Bayes algorithms in the machine learning application scored an accuracy of 85.51% but on the expense of high resource consumption and execution time.

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  • 15.
    Alerstam, Thomas
    et al.
    Lund University.
    Bäckman, Johan
    Lund University.
    Johanna, Grönroos
    Kristianstad University, Faculty of Natural Science, Research environment Man & Biosphere Health (MABH). Kristianstad University, Faculty of Natural Science, Avdelningen för miljö- och biovetenskap.
    Olofsson, Patrik
    Heberg, Sweden.
    Strandberg, Roine
    Lund University.
    Hypotheses and tracking results about the longest migration: the case of the arctic tern2019In: Ecology and Evolution, E-ISSN 2045-7758Article in journal (Refereed)
    Abstract [en]

    The arctic tern Sterna paradisaea completes the longest known annual return migration on Earth, traveling between breeding sites in the northern arctic and temperate regions and survival/molt areas in the Antarctic pack‐ice zone. Salomonsen (1967, Biologiske Meddelelser, Copenhagen Danske Videnskabernes Selskab24, 1) put forward a hypothetical comprehensive interpretation of this global migration pattern, suggesting food distribution, wind patterns, sea ice distribution, and molt habits as key ecological and evolutionary determinants. We used light‐level geolocators to record 12 annual journeys by eight individuals of arctic terns breeding in the Baltic Sea. Migration cycles were evaluated in light of Salomonsen's hypotheses and compared with results from geolocator studies of arctic tern populations from Greenland, Netherlands, and Alaska. The Baltic terns completed a 50,000 km annual migration circuit, exploiting ocean regions of high productivity in the North Atlantic, Benguela Current, and the Indian Ocean between southern Africa and Australia (sometimes including the Tasman Sea). They arrived about 1 November in the Antarctic zone at far easterly longitudes (in one case even at the Ross Sea) subsequently moving westward across 120–220 degrees of longitude toward the Weddell Sea region. They departed from here in mid‐March on a fast spring migration up the Atlantic Ocean. The geolocator data revealed unexpected segregation in time and space between tern populations in the same flyway. Terns from the Baltic and Netherlands traveled earlier and to significantly more easterly longitudes in the Indian Ocean and Antarctic zone than terns from Greenland. We suggest an adaptive explanation for this pattern. The global migration system of the arctic tern offers an extraordinary possibility to understand adaptive values and constraints in complex pelagic life cycles, as determined by environmental conditions (marine productivity, wind patterns, low‐pressure trajectories, pack‐ice distribution), inherent factors (flight performance, molt, flocking), and effects of predation/piracy and competition.

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  • 16.
    Alho, Jussi S.
    et al.
    Ecological Genetics Research Unit, Department of Biosciences, University of Helsinki.
    Herczeg, Gábor
    Ecological Genetics Research Unit, Department of Biosciences, University of Helsinki.
    Söderman, Fredrik
    Population and Conservation Biology, Department of Ecology and Evolution, Evolutionary Biology Centre, Uppsala University.
    Laurilla, Anssi
    Population and Conservation Biology, Department of Ecology and Evolution, Evolutionary Biology Centre, Uppsala University.
    Jönsson, K. Ingemar
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Man and Biosphere Health (MABH).
    Merilä, Juha
    Ecological Genetics Research Unit, Department of Biosciences, University of Helsinki.
    Increasing melanism along a latitudinal gradient in a widespread amphibian: local adaptation, ontogenic or environmental plasticity?2010In: BMC Evolutionary Biology, E-ISSN 1471-2148, Vol. 10, p. 317-Article in journal (Refereed)
    Abstract [en]

    BackgroundThe thermal benefits of melanism in ectothermic animals are widely recognized, but relatively little is known about population differentiation in the degree of melanism along thermal gradients, and the relative contributions of genetic vs. environmental components into the level of melanism expressed. We investigated variation in the degree of melanism in the common frog (Rana temporaria; an active heliotherm thermoregulator) by comparing the degree of melanism (i) among twelve populations spanning over 1500 km long latitudinal gradient across the Scandinavian Peninsula and (ii) between two populations from latitudinal extremes subjected to larval temperature treatments in a common garden experiment.

    ResultsWe found that the degree of melanism increased steeply in the wild as a function of latitude. Comparison of the degree of population differentiation in melanism (PST) and neutral marker loci (FST) revealed that the PST > FST, indicating that the differences cannot be explained by random genetic drift alone. However, the latitudinal trend observed in the wild was not present in the common garden data, suggesting that the cline in nature is not attributable to direct genetic differences.

    ConclusionsAs straightforward local adaptation can be ruled out, the observed trend is likely to result from environment-driven phenotypic plasticity or ontogenetic plasticity coupled with population differences in age structure. In general, our results provide an example how phenotypic plasticity or even plain ontogeny can drive latitudinal clines and result in patterns perfectly matching the genetic differences expected under adaptive hypotheses. 

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  • 17.
    Ali, Hayder
    et al.
    Kristianstad University, School of Health and Society.
    Spets, Rasmus
    Kristianstad University, School of Health and Society.
    Virtualisering av skrivbordsmiljöer: en teknisk jämförelse2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta arbete syftar till en jämförelse av olika skrivbordsvirtualiserings produkter och hur respektive miljö ser ut. I utredandeavsnittet presenteras information om skrivbordsvirtualiserings olika lösningar och hur de fungerar. Arbetet redogör för de två stora aktörerna inom detta område, Citrix och VMware. Utredandeavsnittet presenterar även lite information om Nvidias grafiklösningar i de olika miljöerna. Genomförandeavsnittet presenterar information från intervjuer med representanter från de två stora aktörerna. Arbetet presenterar även information från en representant från Nvidia, USA. Intervjuerna har skett via e-mail eftersom personligt möte varit väldigt svårt att lösa. Intervjuerna behandlar frågor om respektive lösning om hur de fungerar och även om användarvänlighet och åtkomst för användare. Fokus ligger på användarvänlighet och åtkomst för användare i respektive lösning. Efter arbetet kan det dras några slutsatser. Främst att de två miljöerna som undersökts är ganska lika när det gäller virtualisering av skrivbord. De är uppbyggda på liknande sätt och fungerar på nästan samma sätt när det gäller åtkomst för användare.

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  • 18.
    Ali, Viann
    Kristianstad University, Faculty of Business.
    Ett designförslag: en mobilapplikation som kan realtidsdiagnostisera patienter utanför sjukhuset och påskynda utryckning vid hjärtstillestånd2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Research shows that cardiac arrest is common outside hospitals and that they usually have a fatal outcome if they do not receive care as soon as possible. Many cardiac arrests occur in private settings where there is no pacemaker, family member or outsider who can help. The purpose of this study is to find out how a remote monitoring system with a user interface through an app can be designed to real-time diagnose patients with cardiovascular disease outside the hospital and accelerate emergency response. The study has been based on concept-driven design research with a qualitative approach and interviews with both open and closed questions. The individuals who have been interviewed are cardiologists who work in the cardiology department at Ryhov County Hospital in Jönköping. The chosen method has been combined with a literature search in healthcare technology and UX / UI design. The study results in a proposal for a user interface, through an app, which offers health overview and real-time diagnosis. Using these statistics, algorithms can notify the user in the app if their values are normal or abnormal. The algorithms can also warn the user through notifications in the event of serious health changes when the user needs urgent care. The app also offers site location and that SOS-alarm can be alerted directly in the event of serious health changes. Emergency response can then be accelerated by SOS-alarm sending an ambulance to the place where the patient is located immediately.

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    Kandidatuppsats_Informatik
  • 19.
    Alkufai, Meysah
    Kristianstad University, Faculty of Natural Sciences.
    Fungerar AHA-metoden för epifytiska lavar och mossor?: En studie av naturvärdesindikatorer hos träd i park- och kyrkliga kulturmiljöer2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Old trees in cultural environments are receiving increasing attention in nature conservation due to their high conservation values and provide important habitat for endangered plant and animal species. The purposes of the study were to investigate whether Sörensson's AHA-method is applicable also to mosses and lichens, as well as to compare two environments with old trees. 443 trees were inventoried in Kristianstad, of which 230 in Tivoliparken and 213 in Östra begravningsplatsen. The trees were assessed based on the occurrence of: cavities, barkless areas, and so on. These findings were used to assign each tree to the five AHA classes of varying conservation value. Trees were also searched for predetermined lichens and mosses signalling high conservation value, and a simple count was made of the total number of trivial cryptogam species on each tree. Tivoliparken had a wider scatter of trees among the AHA classes; 56 in the highest value classes (class I and II), 114 in class III, and 60 as resource trees. At Östra begravningsplatsen, half of the oldest trees were in the two highest value classes and 93 in class III. The remaining trees ended up as resource trees. In total, 89 records of 6 signal species were made, and one wood fungus. There was a significant association between AHA class and richness of trivial species when trees of all species were pooled, but no association when beech and linden were assessed separately. These results suggest that the AHA method does not work on cryptogams.

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  • 20.
    Alm, Ia
    et al.
    Kristianstad University, Faculty of Business.
    Lundström, Nicole
    Kristianstad University, Faculty of Business.
    Hur platt kan det vara?: En studie om seniorers förståelse av skeumorfism och platt design inom e-hälsa2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The vast progress of digitization creates problems for the seniors who find it hard to keep up with modern technology development. At the same time, the Swedish government has set itself the goal of digitizing health care by 2025. In connection with the trend of using flat design in digital platforms, the situation of seniors is further complicated and may have a negative effect in expanding the digital divide.

    Previous research shows that the style of the flat design is more difficult to understand than the traditional, skeuomorphic design previously used, as flat design lacks affordances. The aim of this thesis has been to investigate whether flat design is more difficult for seniors to understand than traditional skeuomorphic design, as well as how the design principle affordance could solve the problem of understanding flat design.

    The thesis has been guided by the question: How are seniors' understanding of flat design compared to traditional design in the context of websites and what significance does affordance have to support their understanding? To answer the question, a quantitative questionnaire survey and a qualitative observation study have been conducted to investigate the variables of the question based on previous theories. The result shows that affordance does not seem to affect how seniors understand a design interface. On the other hand, indications suggest that design principles such as visual clues, or signifiers, are important to consider when designing for a senior audience design. 

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  • 21.
    Alm, Robert
    et al.
    Kristianstad University, Faculty of Natural Sciences.
    Imeri, Lavdim
    Kristianstad University, Faculty of Natural Sciences.
    A performance comparison between graph databases: Degree project about the comparisonbetween Neo4j, GraphDB and OrientDB on different operations2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this research we study what is the theoretical complexity of Neo4J, OrientDB and GraphDB, (three known Graph Databases that can be accessed by a Java instance), and how this complexity is manifested in a real life performance, To study their practical performance, a software was implemented and named as a profiler, which is capable to profile, (to record the time that is needed), each operation, and display the results in an accurate and organized manner. The technical documentation of those 3 databases was reviewed as well, to identify how the databases work, and what are their strong and weak points. By the profiling process, the best performance was displayed by Neo4J, and while OrientDB failed to deliver, GraphDB takes the second place in terms of performance. We can identify a potential in OrientDB’s approach, but its structure is too complex and rigid. Neo4J has a robust structure and an architecture that gives to it a great performance, while the Cypher syntax, which Neo4J uses, minimizes the possibility of human error. GraphDB is optimized for large scale public-data operations but performs well as a stand-alone solution as well.

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  • 22. al-Rifaie, Fatimah Majid
    et al.
    al-Rifaie, Mohammad Majid
    Storbritannien.
    Maximising overlap score in DNA sequence assembly problem by Stochastic Diffusion Search2016In: Intelligent systems and applications: extended and selected results from the SAI Intelligent Systems Conference (IntelliSys) 2015 / [ed] Yaxin Bi,Supriya Kapoor, Rahul Bhatia, Berlin, Heidelberg: Springer Berlin/Heidelberg, 2016, p. 301-321Conference paper (Refereed)
    Abstract [en]

    This paper introduces a novel study on the performance of Stochastic DiffusionSearch (SDS) – a swarm intelligence algorithm – to address DNA sequence assembly problem. This is an NP-hard problem and one of the primary problems in computational molecular biology that requires optimisation methodologies to reconstruct the original DNA sequence. In this work, SDS algorithm is adapted for this purpose and several experiments are run in order to evaluate the performance of the presented technique over several frequently used benchmarks. Given the promising results of the newly proposed algorithm and its success in assembling the input fragments, its behaviour is further analysed, thus shedding light on the process through which the algorithm conducts the task. Additionally, the algorithm is applied to overlap score matrices which are generated from the raw input fragments; the algorithm optimises the overlap score matrices to find better results. In these experiments realworld data are used and the performance of SDS is compared with several other algorithms which are used by other researchers in the field, thus demonstrating its weaknesses and strengths in the experiments presented in the paper.

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  • 23.
    Anderson, Rachele
    et al.
    Lund University.
    Jönsson, Peter
    Kristianstad University, Faculty of Education, Avdelningen för psykologi.
    Sandsten, Maria
    Lund University.
    Effects of age, BMI, anxiety and stress on the parameters of a stochastic model for heart rate variability including respiratory information2018In: Proceedings of the 11th International Joint Conference on Biomedical Engineering Systems and Technologies, SCITEPRESS , 2018, Vol. 4, p. 17-25Conference paper (Refereed)
    Abstract [en]

    Recent studies have focused on investigating different factors that may affect heart rate variability (HRV),pointing especially to the effects of age, gender and stress level. Other findings raise the importance of consid- ering the respiratory frequency in the analysis of HRV signals. In this study, we evaluate the effect of several covariates on the parameters of a stochastic model for HRV. The data was recorded from 47 test participants, whose breathing was controlled by following a metronome with increasing frequency. This setup allows for a controlled acquisition of respiratory related HRV data covering the frequency range in which adults breathe in different everyday situations. A stochastic model, known as Locally Stationary Chirp Process, accounts for the respiratory signal information and models the HRV data. The model parameters are estimated with a novel inference method based on the separability features possessed by the process covariance function. Least square regression analysis using several available covariates is used to investigate the correlation with the stochastic model parameters. The results show statistically significant correlation of the model parameterswith age, BMI, State and Trait Anxiety as well as stress level.

  • 24.
    Andersson, Amanda
    et al.
    Kristianstad University, Faculty of Natural Science.
    Sidibé, Linnéa
    Kristianstad University, Faculty of Natural Science.
    Stigande havsnivåers påverkan på kulturmiljöer och naturtyper: En studie längs Skånes kust och i Vellinge kommun2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Stora klimatförändringar sker just nu globalt, en konsekvens av dessa förändringar är stigande havsnivåer längs kusterna. En förhöjd havsnivå kan utgöra ett hot mot lågt liggande miljöer och andra värden i anslutning till kusten. I Sverige har ingen tidigare studie gjorts på hur kulturmiljöer och naturtyper påverkas av klimatförändringar så som stigande havsnivåer. Syftet med denna studie är att undersöka i vilken utsträckning kulturmiljöer och naturtyper längs Skånes kust kommer att påverkas av stigande havsnivåer på 1 m, 2 m och 3 m. Resultatet av den extensiva studien längs Skånes kust visar att det är flest kulturmiljöer som påverkas vid en förändrad havsnivå på 1 m i Vellinge och Lomma kommun, då 41 st respektive 15 st lämningar kommer att påverkas. De naturtyper som påverkas i störst omfattning längs Skånes kust är glasörtstränder, salta strandängar och strandängar vid Östersjön. Detaljstudien i Vellinge kommun visar att Riksantikvarieämbetets värderingsplattform är svår att applicera på kulturmiljöer utan lämpar sig bättre att applicera på enskilda objekt eftersom plattformens värderingsmall är för abstrakt för att identifiera och täcka in alla värden som en kulturmiljö omfattar. Länsstyrelsen i Västra Götalands åtgärdsförslag går att tillämpa olika bra beroende på kulturmiljön och vilka objekt den utgör. Även här är det lättare att tillämpa åtgärdsförslagen beroende på enskilda objekt, snarare än en hel kulturmiljö. Åtgärdsförslagen är svåra att applicera på naturtyper eftersom de flesta åtgärderna skulle skapa en barriär för växt- och djurlivet.

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  • 25.
    Andersson, Anders-Petter
    et al.
    Kristianstad University, School of Health and Society, Avdelningen för Hälsovetenskap II. Kristianstad University, Research Platform for Collaboration for Health.
    Cappelen, Birgitta
    The Oslo School of Architecture and Design.
    Musical interaction for health improvement2014In: Oxford handbook of interactive audio / [ed] Karen Collins, Bill Kapralos, Holly Tessler, Oxford: Oxford University Press , 2014, p. 247-262Chapter in book (Refereed)
    Abstract [en]

    During the past decade, tangible sensor technologies have matured and become less expensive and easier to use, leading to an explosion of innovative musical designs within video games, smartphone applications, and interactive art installations. Interactive audio has become an important design quality in commercially successful games like Guitar Hero , and a range of mobile phone applications motivating people to interact, play, dance, and collaborate with music. Parallel to the game, phone, and art scenes, an area of music and health research has grown, showing the positive results of using music to promote health and wellbeing in everyday situations and for a broad range of people, from children and elderly to people with psychological and physiological disabilities. Both quantitative medical and ecological humanistic research show that interaction with music can improve health, through music’s ability to evoke feelings, motivate people to interact, master, and cope with difficult situations, create social relations and experience shared meaning. Only recently, however, the music and health field has started to take interest in interactive audio, based on computer-mediated technologies’ potential for health improvement. Here, we show the potential of using interactive audio in what we call interactive musicking in the computer-based interactive environment Wave. Interactive musicking is based on musicologist Christopher Small’s concept “musicking”, meaning any form of relation-building that occurs between people, and people and things, related to activities that include music. For instance, musicking includes dancing, listening, and playing with music (in professional contexts and in amateur, everyday contexts). We have adapted the concept of "musicking" on the design of computer-based musical devices. The context for this chapter is the research project RHYME. RHYME is a multidisciplinary collaboration between the Centre for Music and Health at the Norwegian Academy of Music, the Oslo School of Architecture and Design (AHO), and Informatics at the University of Oslo. Our target group is families with children with severe disabilities. Our goal is to improve health and wellbeing in the families through everyday musicking activities in interactive environments. Our research approach is to use knowledge from music and health research, musical composition and improvisation, musical action research, musicology, music sociology, and soundscape studies, when designing the tangible interactive environments. Our focus here is interaction design and composition strategies, following research-by-design methodology, creating interactive musicking environments. We describe the research and design of the interactive musicking environment Wave, based on video documentation, during a sequence of actions. Our findings suggest some interactive audio design strategies to improve health. We base the design strategies on musical actions performed while playing an instrument, such as impulsive or iterative hitting, or sustainable stroking of an instrument. Musical actions like these can also be used for musicking in everyday contexts, creating direct sound responses to evoke feelings that create expectations and confirm interactions. In opposition to a more control-oriented, instrument and interface perspective, we argue that musical variation and narrative models can be used to design interactive audio, where the audio is seen as an actor taking many different roles, as instrument, co-musician, toy, etc. In this way, the audio and the interactive musicking environments will change over time, answering with direct response, as well as nose-thumbing and changing response, motivating creation, play, and social interaction. Musical variation can also be used to design musical backgrounds and soundscapes that can be used for creating layers of ambience. These models create a safe environment and contribute to shared meaning.

  • 26.
    Andersson, Anders-Petter
    et al.
    Kristianstad University, School of Health and Society.
    Cappellen, Birgitta
    The Oslo School of Architecture and Design.
    Same but different: composing for interactivity2008In: Audio Mostly Conference: A Conference on Interaction with Sound, October 22-23 2011, Luleå University, Interactive Institute, Sonic, 2008, p. 80-85Conference paper (Refereed)
    Abstract [en]

    Based on experiences from practical design work, we try to show, what we believe, are the similarities and differences, between composing music for interactive media compared to linear music. In our view, much is the same, built on traditions that have been around for centuries within music and composition. The fact that the composer writes programming code is an essential difference. Instead of writing one linear work, he creates infinite numbers of potential musics that reveal themselves as answers to user interactions in many situations. Therefore, we have to broaden our perspectives. We have to put forward factors that earlier was implicit in the musical and music making situations, no matter if it was the concert hall, the church, or the club. When composing interactive music we have to consider the genre, the potential roles the listener might take, and the user experience in different situations.

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  • 27.
    Andersson, Anna
    et al.
    Kristianstad University, Faculty of Natural Science.
    Andersson, Sanna
    Kristianstad University, Faculty of Natural Science.
    Aluntillverkningens betydelse för skogen: med ett exempel från Andrarums alunbruk i Skåne 1637–19122020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Andrarums alummill left a great impression in the surrounding forest. The mill required large resources of wood to be able to process alum slate to alum, which meant that the need for wood resources was big. The area around the alummill was given a mark in the terrain in 1730, with 21 large stones placed along the circular periphery, which is called Verkalinjen. The purpose of the study is to investigate the importance of alum production for the forest inside the Verkalinjen. The focus of the thesis was to study the importance of wood consumption during the years when the mill was active. In addition to a general study for the entire area within the Verkalinjen, the study was delimited to the properties Breabäck, Snärpe, Rugeröd and Nybygget. The method and materials used in the essay are studies of historical map material and analysis of documents belonging to the archive at Christinehof. Maps were rectified and digitized in GIS-ArcMap, inside the Verkalinjen and in the selected research area. The result shows that the forest in the study area has decreased greatly between 1684 and 1704, from having been a forest area, to been transformed into a sparse and thin beech forest. The use of the forest has changed over time and the results show that there was a forest shortage in the study area during the 18th century. In the middle of the 17th century, it is believed that the forest in the Andrarums alummill district will never meet the needs of the mill in the long term and it will be difficult for the forest to recover. Replanting, housekeeping and grazing ban take effect, but despite this, an open and woodless landscape emerges during the 18th century, with elements of small islands of forest. The result also shows that the forest has recovered in the early 1900s and there is then a great variety of trees in the area, with both deciduous and coniferous forests.

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  • 28.
    Andersson, Annie
    et al.
    Kristianstad University, Faculty of Natural Science.
    Habainy, Rana
    Kristianstad University, Faculty of Natural Science.
    Friluftsliv i Östra Göinge: en undersökning om attityd och natur i Östra Göinge kommun2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis focuses on the attitude between nature and the residents of Östra Göinge municipality. The purpose of this research and thesis is to provide a clearer picture of the resident’s outdoor life and relationship to nature within the municipality. In addition, this research considered possible development opportunities in the outdoor life category within the community while also addressing the question of accessibility to green areas. This research used an online survey, distributed on Facebook, to groups linked to Östra Göinge. The results from the survey show that even though the residents of the community are satisfied with the access to green areas in the municipality, they still see development opportunities which will help promote outdoor life in Östra Göinge.

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  • 29.
    Andersson, Eva
    Kristianstad University, Faculty of Natural Science.
    Toxikologisk tillväxtstudie av sötvattenalgen Raphidocelis subcapitata: En jämförelse mellan flödescytometer NovoCyte och automatisk cellräknare TC202018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Biological toxicity tests are performed by exposing a test organism to different concentrations of chemicals over a certain period of time. Results from acute studies are presented as EC50 (Effect Concentration, affecting 50% of the population). Tests used as a basis for risk assessments shall be performed in a quality acceptable way based on the International Organization for Standardization (ISO) and Good Laboratory Practice (GLP). The aim of this study was to study the toxic effect of potassium dichromate on unicellular green algae R. subcapitata, by counting cells with two different apparatus: flow cytometer and automatic cell counter. Additionally, to compare the EC50 mean values against the ISO 8692 value for control of test precision and to compare accuracy and analytical time of two methods. Potassium dichromate was used for growth inhibition in toxicity tests. The EC50 results showed no statistically significant difference between the two instruments (p = 0.47). The accuracy of acute toxicity analysis was confirmed as valid as both EC50 average measurement values compared to ISO 8692 value were found within the 95% confidence interval. When comparing the two methods of the study, greater spread was observed around the mean value in the cell count's results, where three EC50 values were outside 95% CI. The result of the flow cytometer had less spread and higher accuracy compared to the cell count. The study showed that flow cytometers could be used in future toxicological tests with algae, but several repeated tests are required to confirm the benefits of analysis with the flow cytometer.

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  • 30.
    Andersson, Fredrik
    et al.
    Kristianstad University, Faculty of Natural Science.
    Hansson, Mattias
    Kristianstad University, Faculty of Natural Science.
    Expansionsmöjligheter hos Acheta domesticus: En studie om syrsmjölets påverkan på färg,textur, gillande och expansion i extruderadmajskrok.2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In line with a growing world population, higher demands are put on primary producers to supply raw materials in adequate quantities. Research in the area is of great importance in finding new sustainable sources of nutrients such as protein, which presently brings with it many environmental disadvantages. As the EU approves insects as food, more people are becoming aware of potential benefits they can provide. The purpose of this report is to investigate the effect of the addition of cricket flour on the color, texture, liking and expansion of an extruded corn puff. This is a step towards the implementation of insects in the Western diet. By analyzing the water and protein content of the extruded product, as well as measuring its color, texture, radial expansion and consumer appreciation, collected data can be compared and any correlations can be shown. The results of the study show that with a higher proportion of cricket flour the texture becomes more compact, shows less expansion and a color change toward a darker tone. The samples with a lower proportion of added cricket flour, and thus a better expansion, received the highest points of liking on all the questions in the consumer test.

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  • 31.
    Andersson, Jens A.
    et al.
    Lund University.
    Arvidsson, Ake
    Kristianstad University, School of Health and Society, Avdelningen för Design och datavetenskap. Ericsson AB.
    Du, Manxing
    Acreo Swedish ICT AB, Kista, Sweden.
    Zhang, Huimin
    Acreo Swedish ICT AB, Kista, Sweden.
    Kihl, Maria
    Lund University.
    Host, Stefan
    Lund University.
    Lagerstedt, Christina
    Acreo Swedish ICT AB, Kista, Sweden.
    User profiling for pre-fetching or caching in a catch-Up TV network2016In: 2016 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB), 2016Conference paper (Refereed)
    Abstract [en]

    We investigate the potential of different pre-fetching and/or caching strategies for different user behaviour with respect to surfing or browsing in a catch-up-TV network. To this end we identify accounts and channels associated with strong or weak surfing or browsing respectively and study the distributions of hold times for the different types of behaviour. Finally we present results from a request prediction model and a caching simulation for the different types of behaviour and find that the results are relatively similar.

  • 32.
    Andersson, Johanna
    Kristianstad University, Faculty of Natural Science.
    Heteronormativa blommor och könsrollsbundna bin, är naturen verkligen så normativ?: en analys av hur läroböcker i biologi och naturkunskap rekonstruerar normer om kön och sexualitet vid beskriviningar av djurs beteende2020Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta arbete handlar om hur normer om kön och sexualitet (re)konstrueras i biologiundervisningen, och fokuserar på innehåll om hur djurs beteende beskrivs. Tidigare forskning pekar på att undervisningen och läroböcker inom biologi och naturkunskap är mycket heteronormativ och förklarar kvinnor och män i dikotomiska termer. En del av forskningsrapporterna uppmärksammade också att det finns en svårighet att sammanföra det biologiska innehållet och innehåll som behandlar sexualitet, genus och relationer i undervisningen. Endast två studier är gjorda på hur normer om kön och sexualitet konstrueras då djurs beteende beskrivs. Då forskning visar att biologin och dess förklaringar på djurs beteende har betydelse för vad vi människor ser som naturliga beteenden för oss, kan innehåll om djurs beteende i undervisnngen ge normativa föreställningar om kön och sexualitet. Undersökningen gjordes utifrån frågeställningarna: 

    Vilka förklaringar om djurs beteende utifrån kön och sexuella strategier framställs i läroböcker för kurserna biologi 1 och naturkunskap 2 för gymnasieskolan?

    Vilka följemeningar om kön och sexualitet kan dessa beskrivningar ge elever? 

    Tre läroböcker i biologi och tre läroböcker i naturkunskap analyserades med diskursanalys som analysmetod. Resultatet visade bland annat att det fanns betydligt mer innehåll i biologiböckerna än naturkunskapsböckerna, att antalet normativa beskrivnngar skiljde sig mycket åt mellan böckerna, och att en del böcker riskerar att ge eleverna normativa föreställningar om kön och sexualitet. Följemeningar som identifierades för några av böckerna var bland annat att beteendemässiga könsskillnader är biologiskt bestämt och att heterosexualiteten är naturlig. Perspektiv som är viktiga för arbetet och som är utgångspunkter är teorin om diskurser, normer, queerteori, samt queer- och genusperspektiv på biologi.

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  • 33.
    Andersson, Josefina
    et al.
    Kristianstad University College, Department of Mathematics and Science.
    Axelsson, Lina
    Kristianstad University College, Department of Mathematics and Science.
    Cata - a former homeland village affected by Betterment, Eastern Cape, South Africa2005Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [en]

    This study focus on the house ruins and land use in Nyokana, a former village section in Cata, by looking at their location, number and the people who lived there and their living before the Betterment plan was carried through. This is done by studying an old map and documents of Cata, field studies with GPS-using and by interviewing mostly old inhabitants. The result is a basis for the development of the planned tourism track within the heritage project, wich runs by BRC and University of Fort Hare.

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  • 34.
    Andersson, Kristofer
    Kristianstad University, School of Education and Environment.
    Svedjebrukets slutskede: En studie av svedjebruket och landskapet i Algustorp, Röke socken, norra Skåne, ca 1800-19002017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Relativt lite forskning har de senaste årtiondena bedrivits gällande svedjebruket, i synnerhet förekomsten och utbredningen av svedjeland inom enskilda byar. Arealen svedjad mark i förhållande till arealen åkermark i byn Algustorp, Röke socken, norra Skåne utgör grunden för denna studie. Gunhild Weimarck publicerade 1953 en avhandling där arealen svedjad mark jämförs med arealen åkermark i Lönsboda, Örkened socken, nordöstra Skåne. För denna uppsats är jämförelser mellan de två byarna fundamental, det vill säga en komparativ studie där likheter och skillnader diskuteras utifrån olika parametrar. Uppsatsen ska dessutom ge ökad kännedom om svedjebrukets förekomst i fem närbelägna byar i anslutning till Algustorp, belysa svedjandets betydelse för agrarsamhället och framför allt redogöra för svedjelandens omfattning inom byn Algustorp. För att möjliggöra detta har källmaterial i form av frågelistsvar, jordeböcker och historiskt kartmaterial varit grundläggande för studien. Analyser av geografisk information i applikationen ArcMap har underlättat beräkningen av arealen svedjemark respektive åkermark i Algustorp. Resultatet visar att arealen svedjeland i Algustorp var mindre än byns åkerareal, till skillnad från Lönsboda, där svedjemarkens areal istället var större i förhållande till byns åkermark. Detta fenomen tycks bero på regionala skillnader, det vill säga olikartade markförhållanden i de olika byarna. Tillgången på odlingsbar mark framstår som mycket liten i Lönsboda. Därmed förekom större arealer svedjemark i Lönsboda till skillnad från Algustorp, där förutsättningarna för spannmålsodling till synes är mera gynnsamma. Det är med stor sannolikhet naturgivna förhållanden, främst jordartssammansättningen, som pådrivit ett större behov av att nyttja svedjebruk i Lönsboda.

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  • 35.
    Andersson, Robert
    Kristianstad University, School of Education and Environment.
    Fenologisk studie av björk (Betula alba) och ek (Quercus robur): En regional jämförelse av historiska och nutida fenologi- och temperaturdata2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Med ett allt varmare klimat har observationer av främst växter visat sig vara värdefulla för vilka effekter en klimatförändring kan få på ekosystemen. Observationer av tidpunkten för dessa företeelser är det som benämns fenologi och utgör enligt flera studier indikationer på att jordens klimat förändras. Målet med min undersökning är att se om klimatförändringar har påverkat lövsprickningen i södra Sverige. För att mer specifikt undersöka tidpunkten för lövsprickning har jag avgränsat mig till björk (Betula alba) och ek (Quercus robur) i fyra län i södra Sverige. För att undersöka eventuella fenologiska förändringar har jag använt/jämfört historiska data från 1873–1923 med nutida 2008–2016 och beräknat hur lövsprickningsdatumen och temperatur har förändrats. För att kunna undersöka sambandet mellan lövsprickning och temperatur har månadsmedeltemperaturen använts för jämförelse tre månader bakåt räknat från lövsprickningsdatum. Resultatet visade att både temperaturen och lövsprickningen har förändrats. I undersökningsområdet har medeltemperaturen i genomsnitt ökat med 2°C, medan lövsprickningen har tidigarelagts för björk och ek med 16,5 respektive 11,5 dagar i genomsnitt. Resultatet visar också att de fenologiska förändringarna är statistiskt signifikanta. Däremot är det mer osäkert att förändringarna beror på temperaturen, trots starka kopplingar mellan temperaturförändringarna och fenologiska förändringar. Det skulle kunna vara variationen i temperaturen, snarare än medeltemperaturen som är viktigast för lövsprickningen.

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  • 36.
    Andersson, Sofia
    et al.
    Kristianstad University, School of Education and Environment.
    Mhamutovic, Naida
    Kristianstad University, School of Education and Environment.
    Skyddszoner som fosforfällor: En studie om skyddszonernas förmåga att förhindra fosforläckage2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Phosphorus leaking from our fertilized arable land contributes to eutrophication of lakes and seas and travels among other things, with particles from fertilized soil. Straightening of rivers and ditching helps drained water travel quickly from the arable land lakes and seas. To avoid phosphorus leaking there are buffer zones that are placed between the field and the streams with the purpose of captivating the phosphorus. One previous study has shown that a risk occurs for phosphorus saturation on the lands adjacent to the streams (Borggaard, Moberg & Sibbesen 1991; Vought et al 1994; Svanbäck et al 2013).   

      

    This thesis aims to see if today’s buffer zones are saturated or can take up more phosphorus and if the difference in the type of soil matter to the result. The effects of pH and organic matter on the phosphorus content are also examined. The soils clay, moraine  and sand are studied in this thesis. The work also aims to demonstrate the changes in the landscape and history of the buffer zones.  

      

    Soil samples were collected from 15 buffer zones around Kristianstad. The samples were dried, sieved and then shaken with water containing a known amount of phosphorus. Uptake of phosphorus was then measured. Historical and contemporary maps were also studied to see the landscape change.  

      

    The analysis showed that nine out of fifteen zones were saturate. The three soil types each had three saturated zones and two unsaturated and the difference was not significant between the soil types. For the soil clay results showed that pH and organic matter content influenced the amount of phosphorus in which, a higher pH, showed a higher phosphorus content and the higher organic matter reviled a lower amount if phosphorus. For moraine results showed same as in clay but the relation between the organic matter and how it affected the phosphorus content was not significant. The result for the sand was that higher pH in the soil resulted to higher phosphorus content. The same effect was seen for the organic matter in sand which means that the phosphorus content rises with higher organic matter.   

    The buffer zones that we studied occur mostly on land that has been used as arable land for at least 100 years, while others have previously been used as wet- or other meadows or pastures. The areas that have been arable lands a long time have probably been fertilized heavily during the postwar period. Establishing buffer zones may therefore have contributed to recreate the landscape as it was before the rationalization of agriculture in the late 1950s. Buffer zones prevent erosion and help to preserve biodiversity both in the stream and buffer zone. Today's eligible zones may only be grassed but one could imagine future protection zones with salix / tree where the phosphorus is removed through the wood.  

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  • 37.
    Andersson, Tobias
    et al.
    Kristianstad University, Faculty of Natural Sciences.
    Reinholdsson, Håkan
    Kristianstad University, Faculty of Natural Sciences.
    REST API vs GraphQL: A literature and experimental study2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study is to compare the two architectural techniques REST and GraphQL. This thesis will compare the two techniques and what defines them. A literature study and experimental study are carried out by the researchers. Four applications have been developed that include the ability to disable and to enable caching for both technologies to test the performance effect of caching. Earlier work has not covered the effects on caching related to these two frameworks. The literature study results point to that REST services are up to date and GraphQL is a technique with a shorter history, but that has declared growth in the industry and is a well suited choice for example when bandwidth matters in mobile phone applications. In the experimental study the tests showed slightly better results on average for REST API in terms of total response time (ms). Depending on the intended project there are many factors that need to be evaluated before making a decision on which framework to use. 

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  • 38.
    Andiappan, Anand Kumar
    et al.
    Department of Biological Sciences, National University of Singapore.
    Nilsson, Daniel
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Biomedicin.
    Halldén, Christer
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Biomedicin.
    Yun, Wang De
    Department of Otolaryngology, National University of Singapore.
    Säll, Torbjörn
    Department of Cell and Organism Biology, Lund University.
    Cardell, Lars Olaf
    Division of ENT Diseases, CLINTEC, Karolinska Institutet.
    Tim, Chew Fook
    Department of Biological Sciences, National University of Singapore.
    Investigating highly replicated asthma genes as candidate genes for allergic rhinitis2013In: BMC Medical Genetics, E-ISSN 1471-2350, Vol. 14, p. 51-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Asthma genetics has been extensively studied and many genes have been associated with the development or severity of this disease. In contrast, the genetic basis of allergic rhinitis (AR) has not been evaluated as extensively. It is well known that asthma is closely related with AR since a large proportion of individuals with asthma also present symptoms of AR, and patients with AR have a 5-6 fold increased risk of developing asthma. Thus, the relevance of asthma candidate genes as predisposing factors for AR is worth investigating. The present study was designed to investigate if SNPs in highly replicated asthma genes are associated with the occurrence of AR.

    METHODS: A total of 192 SNPs from 21 asthma candidate genes reported to be associated with asthma in 6 or more unrelated studies were genotyped in a Swedish population with 246 AR patients and 431 controls. Genotypes for 429 SNPs from the same set of genes were also extracted from a Singapore Chinese genome-wide dataset which consisted of 456 AR cases and 486 controls. All SNPs were subsequently analyzed for association with AR and their influence on allergic sensitization to common allergens.

    RESULTS: A limited number of potential associations were observed and the overall pattern of P-values corresponds well to the expectations in the absence of an effect. However, in the tests of allele effects in the Chinese population the number of significant P-values exceeds the expectations. The strongest signals were found for SNPs in NPSR1 and CTLA4. In these genes, a total of nine SNPs showed P-values <0.001 with corresponding Q-values <0.05. In the NPSR1 gene some P-values were lower than the Bonferroni correction level. Reanalysis after elimination of all patients with asthmatic symptoms excluded asthma as a confounding factor in our results. Weaker indications were found for IL13 and GSTP1 with respect to sensitization to birch pollen in the Swedish population.

    CONCLUSIONS: Genetic variation in the majority of the highly replicated asthma genes were not associated to AR in our populations which suggest that asthma and AR could have less in common than previously anticipated. However, NPSR1 and CTLA4 can be genetic links between AR and asthma and associations of polymorphisms in NPSR1 with AR have not been reported previously.

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  • 39.
    Areskoug, Mats
    et al.
    Malmö högskola.
    Ekborg, Margareta
    Malmö högskola.
    Lindahl, Britt
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Learning in Science and Mathematics (LISMA).
    Rosberg, Maria
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Learning in Science and Mathematics (LISMA).
    Naturvetenskapens bärande idéer: för lärare F-62013Book (Other academic)
    Abstract [sv]

    Att undervisa i de naturorienterande ämnena (NO) i de tidiga skolåren är ett utmanande, spännande och roligt uppdrag. Dessa ämnen spänner dock över stora innehållsområden och därför kan det vara svårt att få en överblick och välja ett innehåll som är lämpligt för åldersgruppen.

    Den här boken hjälper lärare att få grepp om det viktigaste innehållet i de naturvetenskapliga ämnena. Författarna beskriver naturvetenskaperna ur ett helhetsperspektiv och ger en övergripande struktur, som kompletteras med relevanta begrepp. Naturvetenskapens bärande idéer förklaras mer i detalj och utifrån en rad konkreta vardagliga exempel. Innehållet diskuteras i förhållande till Läroplan för grundskolan, förskoleklassen och fritidshemmet (Lgr 11).

    Boken kan användas både som kurslitteratur för blivande lärare och som ämnesfördjupning för verksamma lärare.

  • 40. Areskoug, Mats
    et al.
    Ekborg, Margareta
    Malmö universitet.
    Lindahl, Britt
    Rosberg, Maria
    Kristianstad University, Faculty of Education, Department of Mathematics and Science Education. Kristianstad University, Faculty of Education, Research environment Learning in Science and Mathematics (LISMA).
    Naturvetenskapens bärande idéer: för lärare F-62020 (ed. 3)Book (Other academic)
    Abstract [sv]

    Att undervisa i de naturvetenskapliga ämnena (NO) i de tidiga skolåren är ett utmanande, spännande och roligt uppdrag. Dessa ämnen spänner dock över stora innehållsområden och därför kan det vara svårt att få en överblick och välja ett innehåll som är lämpligt för åldersgruppen.

    Den här boken hjälper läraren att få grepp om det viktigaste innehållet i de naturvetenskapliga ämnena. Naturvetenskapens grundläggande och bärande idéer förklaras detaljerat och belyses med en rad konkreta och vardagliga exempel. Innehållet diskuteras i förhållande till Läroplan för grundskolan, förskoleklassen och fritidshemmet (Lgr 11).

    Boken kan, gärna i kombination med boken Naturvetenskapens bärande idéer i praktiken, användas både som kurslitteratur för blivande lärare och som ämnesfördjupning för verksamma lärare.

    Den 3:e upplagan har reviderats i förhållande till ändringarna i kursplanerna 2020.

  • 41.
    Areskoug, Mats
    et al.
    Malmö Högskola.
    Ekborg, Margareta
    Malmö Högskola.
    Rosberg, Maria
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Learning in Science and Mathematics (LISMA).
    Thulin, Susanne
    Kristianstad University, Research environment Learning in Science and Mathematics (LISMA). Kristianstad University, School of Education and Environment, Avdelningen för Pedagogik. Kristianstad University, Forskningsmiljön Barndom, Lärande och Utbildning (BALU).
    Naturvetenskapens bärande idéer för förskollärare2016 (ed. 1)Book (Other academic)
    Abstract [sv]

    Att arbeta med naturvetenskap i förskolan är ett utmanande, spännande och roligt uppdrag. Alla har vi väl förundrats över barns nyfikenhet och goda observationsförmåga när de möter naturvetenskapliga fenomen. Många förskollärare berättar också att det är tacksamt att arbeta med naturvetenskap.

    Ämnesområdet är stort och det kan vara svårt att som förskollärare få en överblick och veta vad man ska läsa in sig på för att få idéer till relevanta uppgifter att göra tillsammans med barnen.

    Den här boken handlar om de bärande idéerna i naturvetenskap och är tänkt att stödja förskolläraren i strävan att få grepp om det viktigaste innehållet. Ambitionen är att dra upp de stora linjerna snarare än att ge en heltäckande beskrivning. Exempel från vardagliga sammanhang används för att visa på bärkraften i dessa idéer.

    Boken är tänkt som kurslitteratur för blivande förskollärare och ämnesfördjupning för verksamma lärare i förskolan. Innehållet diskuteras i förhållande till förskolans läroplan.

  • 42. Areskoug, Mats
    et al.
    Ekborg, Margareta
    Rosberg, Maria
    Kristianstad University, Faculty of Education, Department of Mathematics and Science Education. Kristianstad University, Faculty of Education, Research environment Learning in Science and Mathematics (LISMA).
    Thulin, Susanne
    Kristianstad University, Faculty of Education, Research environment Learning in Science and Mathematics (LISMA). Kristianstad University, Faculty of Education, Forskningsmiljön Barndom, Lärande och Utbildning (BALU). Kristianstad University, Forskningsmiljön Arbete i skolan (AiS). Kristianstad University, Faculty of Education, Department of Educational Sciences specializing in Pre-School and After School Care, Teaching and Learning. Kristianstad University, Research Platform Collaboration for Education.
    Naturvetenskapens bärande idéer: för förskollärare2020 (ed. 2)Book (Other academic)
    Abstract [sv]

    Att arbeta med naturvetenskap i förskolan är ett utmanande, spännande och roligt uppdrag. Alla har vi väl förundrats över barns nyfikenhet och goda observationsförmåga när de möter naturvetenskapliga fenomen. Många förskollärare berättar också att det är tacksamt att arbeta med naturvetenskap. Ämnesområdet är stort och det kan vara svårt att som förskollärare få en överblick och veta vad man ska läsa in sig på för att få idéer till relevanta uppgifter att göra tillsammans med barnen.

    Den här boken handlar om de bärande idéerna i naturvetenskap och är tänkt att stödja förskolläraren i strävan att få grepp om det viktigaste innehållet. Ambitionen är att dra upp de stora linjerna snarare än att ge en heltäckande beskrivning. Exempel från vardagliga sammanhang används för att visa på bärkraften i dessa idéer.

    Den nya upplagan är reviderad i enlighet med förskolans nya läroplan (Lpfö 18).

  • 43.
    Arnesten, Emilie
    Kristianstad University, School of Education and Environment.
    Hydroarkeologi på Västgötaslätten: en kartstudie av sambandet mellan fornlämningar och förhistorisk hydrologi.2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor thesis investigates hydroarchelogy through several studies of maps, ancient remains and their relationship to the hydrology of the prehistoric landscape in a selected area in Sweden where a prehistoric hydrological situation has been recreated. The focus of this thesis is remains which are located over 1 000 meters from a body of water today, but which have water within 1 000 meters on historical maps.

     

    Ancient remains are generally situated relatively close to the present bodies of water and among the studied remains the dominating types are graves and tools. The majority of the remains date back to the prehistory and between the 18th century and today the land use surrounding the remains has consisted of an increasing part of open field. The water has changed both by natural and antropogen causes and the major antropogen changes started around 1800. The studied area probably has a totally different hydrological appearance today compared to during the prehistory.

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    Hydroarkeologi på Västgötaslätten
  • 44.
    Arvidsson, Daniel
    et al.
    Kristianstad University, School of Health and Society.
    Bergqvist, Joakim
    Kristianstad University, School of Health and Society.
    Bünger, Robin
    Kristianstad University, School of Health and Society.
    IP-telefoni: en teknisk undersökning2011Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [sv]

    Projektet har till syfte att undersöka den revolutionerande tekniken bakom IP-telefoni. Eftersom tekniken är relativt ung så finns det fortfarande mycket att lära om hur det fungerar och hur den används. Projektet behandlar fördelar och nackdelar samt vilka hot som finns och hur man kan känna sig säker när man använder IP-telefoni till vardags. Det primära objektivet med projektet är att få en helhetsbild och förstå hur tekniken verkligen fungerar.

    Vidare behandlas telefonens historia då det är viktigt att se var tekniken har sina rötter och hur den utvecklats sedan dess. Som en röd tråd från telefonens teknologi och det publika telefonnätets rötter görs en jämförelse mellan de två teknologierna för att se skillanderna och förmodade fördelar och nackdelar med de båda systemen. Olika sorters protokoll som har ett nära förhållande till IP-telefoni så som SIP, RTP, UDP och IP behandlas. För att få en sanningsenlig bild över hur vardagliga användare upplever IP-telefoni så har en enkätundersökning angående vanor och möjliga problem gjorts hos de anställda på Region Skåne.

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  • 45.
    Arvidsson, Fredrik
    et al.
    Lund University.
    Jonsson, Lars J.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Birkhofer, Klaus
    Lund University.
    Geographic location, not forest type, affects the diversity of spider communities sampled with malaise traps in Sweden2016In: Annales Zoologici Fennici, ISSN 0003-455X, E-ISSN 1797-2450, Vol. 53, no 3-4, p. 215-227Article in journal (Refereed)
    Abstract [en]

    The latitudinal diversity gradient predicts higher species richness at lower latitudes. Here, we utilize the data from a long-term monitoring with malaise traps to analyse if spider communities in Sweden are affected by geographic gradients and if these effects hold independent of forest type. The species richness and the effective number of species in spider communities were not significantly related to the latitudinal gradient. The effective number of species and the taxonomic distinctness of spider communities were related to longitude, with a higher number, but fewer related species in western parts of Sweden. The species and family composition were significantly related to latitude independent of forest type, with a dominance of Linyphiidae individuals and species in the north. Our study demonstrates the suitability of malaise trap sampling to contribute to a better understanding of local spider communities, as several rare and locally new species were recorded in this study.

  • 46.
    Arvidsson, Åke
    et al.
    Kristianstad University, Faculty of Natural Science, Research environment of Computer science (RECS). Kristianstad University, Faculty of Natural Science, Avdelningen för datavetenskap.
    Grinnemo, Karl-Johan
    Karlstads universitet.
    Chen, Eric Zhi
    Kristianstad University, Faculty of Natural Science, Avdelningen för datavetenskap. Kristianstad University, Faculty of Natural Science, Research environment of Computer science (RECS).
    Wang, Qinghua
    Kristianstad University, Faculty of Natural Science, Research environment of Computer science (RECS). Kristianstad University, Faculty of Natural Science, Avdelningen för datavetenskap.
    Brunström, Anna
    Karlstads universitet.
    Web metrics for the next generation performance enhancing proxies2019In: 2019 27TH INTERNATIONAL CONFERENCE ON SOFTWARE, TELECOMMUNICATIONS AND COMPUTER NETWORKS (SOFTCOM) / [ed] Begusic, D Rozic, N Radic, J Saric, M, IEEE , 2019, p. 171-176Conference paper (Refereed)
    Abstract [en]

    The fast growth of Internet traffic, the growing importance of cellular accesses and the escalating competition between content providers and network operators result in a growing interest in improving network performance and user experience. In terms of network transport, different solutions ranging from tuning TCP to installing middleboxes are applied. It turns out, however, that the practical results sometimes are disappointing and we believe that poor testing is one of the reasons for this. Indeed, many cases in the literature limit testing to the simple and rare use case of a single file download, while common and complex use cases like web browsing often are ignored or modelled only by considering smaller files. To facilitate better testing, we present a broader view which includes domain counts, flow counts and different forms of concurrency to better characterise the complexity around web pages, and from which the potential for different optimisation techniques can be estimated. We also derive numerical values of these metrics for a small set of popular web pages and study similarities and differences between pages with the same kind of content (newspapers, e-commerce and video) and between pages designed for the same platform (computer and smartphone).

  • 47.
    Arvidsson, Åke
    et al.
    Kristianstad University, Faculty of Natural Sciences, Avdelningen för datavetenskap. Kristianstad University, Faculty of Natural Sciences, Research environment of Computer science (RECS).
    Ivanovich, Milosh
    Australien.
    Fitzpatrick, Paul
    Australien.
    Modelling user experience of adaptive streaming video over fixed capacity links2021In: Performance evaluation (Print), ISSN 0166-5316, E-ISSN 1872-745X, Vol. 148, p. 1-12, article id 102199Article in journal (Refereed)
    Abstract [en]

    Streaming video continues to experience unprecedented growth. This underscores the need to identify user-centric performance measures and models that will allow operators to satisfy requirements for cost-effective network dimensioning delivered with an acceptable level of user experience. This paper presents an analysis of two novel metrics in the context of fixed capacity links: (i) the average proportion of a video’s playing time during which the quality is reduced and (ii) the average proportion of videos which experience reduced quality at least once during their playing time, based on an M/M/∞ system. Our analysis is shown to hold for the more general M/G/∞ system for metric (i), but not for (ii) and simulation studies show an unexpected form of sensitivity of metric (ii) to the flow duration distribution, contrary to the norm of increasing variance causing worse performance. At typical operational loads these new metrics provide a more sensitive and information rich guide for understanding how user experience degrades, than the widely used average throughput metric does. We further show that only the combined use of this existing and our new metrics can provide a holistic perspective on overall user performance.

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  • 48.
    Arzel, C.
    et al.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, La Tour du Valat, Le Sambuc, Arles.
    Elmberg, Johan
    Kristianstad University, Department of Mathematics and Science.
    Guillemain, M.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, La Tour du Valat, Le Sambuc, Arles.
    A flyway perspective of foraging activity in Eurasian Green-winged Teal, Anas crecca crecca2007In: Canadian Journal of Zoology, ISSN 0008-4301, E-ISSN 1480-3283, Vol. 85, no 1, p. 81-91Article in journal (Refereed)
    Abstract [en]

    Time-activity budgets in the family Anatidae are available for the wintering and breeding periods. We present the first flyway-level study of foraging time in a long-distance migrant, the Eurasian Green-winged Teal, Anas crecca crecca L., 1758 ("Teal"). Behavioral data from early and late spring staging, breeding, and molting sites were collected with standardized protocols to explore differences between the,sexes, seasons, and diel patterns. Teal foraging activity was compared with that of the Mallard, Anas platyrhynchos L., 1758 and Northern Shoveler, Anas clypeata L., 1758, and the potential effects of duck density and predator-caused disturbance were explored. In early spring, foraging time was moderate (50.5%) and mostly nocturnal (45%). It increased dramatically in all three species at migration stopovers and during molt, mostly because of increased diurnal foraging, while nocturnal foraging remained fairly constant along the flyway. These patterns adhere to the "income breeding" strategy expected for this species. No differences between the sexes were recorded in either species studied. Teal foraging time was positively correlated with density of Teal and all ducks present, but negatively correlated with predator disturbance. Our study suggests that Teal, in addition to being income breeders, may also be considered as income migrants; they find the energy necessary to migrate at staging sites along the flyway.

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  • 49.
    Arzel, Celiné
    et al.
    Kristianstad University, Department of Mathematics and Science.
    Guillemain, M.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, La Tour du Valat, Le Sambuc, Arles.
    Gurd, D.B.
    Centre for Wildlife Ecology, Department of Biological Sciences, Simon Fraser University, Burnaby, BC.
    Elmberg, Johan
    Kristianstad University, Department of Mathematics and Science.
    Fritz, H.
    Centre d’Etudes Biologiques de Chizé, CNRS UPR 1934, Beauvoir-sur-Niort.
    Arnaud, A.
    Station Biologique La Tour du Valat, Le Sambuc, Arles.
    Pin, C.
    Station Biologique La Tour du Valat, Le Sambuc, Arles.
    Bosca, F.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, La Tour du Valat, Le Sambuc, Arles.
    Experimental functional response and inter-individual variation in foraging rate of teal (Anas crecca)2007In: Behavioural Processes, ISSN 0376-6357, E-ISSN 1872-8308, Vol. 75, no 1, p. 66-71Article in journal (Refereed)
    Abstract [en]

    The functional response, i.e. the change in per capita food intake rate per time unit with changed food availability, is a widely used too] for understanding the ecology and behaviour of animals. However, waterfowl remain poorly explored in this context. In an aviary experiment we derived a functional response curve for teal (Anas crecca) foraging on rice (Oryza sativa) seeds. We found a linear relationship between intake rate and seed density, as expected for a filter-feeder. At high seed densities we found a threshold, above which intake rate still increased linearly but with a lower slope, possibly reflecting a switch from filter-feeding to a scooping foraging mode. The present study shows that food intake rate in teal is linearly related to food availability within the range of naturally occurring seed densities, a finding with major implications for management and conservation of wetland habitats.

  • 50.
    Arzel, Céline
    et al.
    Department of Biology, University of Turku.
    Dessborn, Lisa
    Kristianstad University, School of Education and Environment.
    Nummi, Petri
    Pöysä, Hannu
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Sjöberg, Kjell
    Does changing spring phenology affect short and long distance migratory waterfowl similarly?2010In: The abstract book: Symposium : The global environmental change: messages from birds. Espoo, 17-19 November, 2010, p. 43-Conference paper (Other academic)
    Abstract [en]

    Among waterfowl, most ducks may be considered income breeders due to their small body size and their limited capacity to store energy. Therefore limited access to resources on their breeding grounds is likely to affect their breeding schedule and potentially output. At northern latitudes, ice break up dictates the access to the breeding lakes. An early ice break up allows for early access to the breeding site and its feeding resources, and potentially leading to higher breeding output than after a late ice break up. Short distance migrants are thus more likely to adapt to ice break up conditions than long distance migrants which have to cope with weather conditions en route and local resource accessibility along the migratory path. Using 20 years of data on breeding phenology and success of 3 species of ducks differing in their migratory strategy - Teal Anas crecca, Mallard Anas platyrhynchos and Common Goldeneye Bucephala clangula - in a watershed in Finland, we test the idea that variation in spring phenology affects the reproductive performance of duck species differently depending on their migration pattern.

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