284 research outputs found

    The effect of hunting on the beaver population in FÀrnebofjÀrdens National Park

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    The beaver hunt in FÀrnebofjÀrdens national park started in 2002. The aim of the hunt was to decrease the beaver population and save the deciduous trees close to the waterline which are very important for many other species in the national park. The northern part of the national park is however free from beaver hunt. In this study I wanted to see if the hunt did in fact decrease the beaver population or not. My first hypothesis is: The yearly growth of the population is negative or lower in the hunting area. Hypothesis number two is: The lodges in the hunting area are less active than the lodges in the area without hunt. Data from the inventory and hunting reports was handed out by The County administration board in GÀvleborg. There are in total 28 active lodges in the national park in 2017, 18 of those are in the area with hunt and 10 are in the area without hunt. The hunting pressure lies between 18% to 67% of the estimated population. Despite the high hunting pressure, the population does not decrease significantly. The population does neither respond to the variety of hunting pressure. The reason why the population does not decrease despite the hunt can be because beavers come from other rivers and in to the national park and occupy the empty lodges

    Characterization of Innate Cellular Modulators of Retroviral Infection

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    HIV-1 is a retrovirus that causes AIDS, a condition that is characterized by progressive failure of the immune system and emerging opportunistic infections. Research aiming at understanding mechanisms for retroviral spread and pathogenesis has recently started to focus on the innnate immune system and factors that have been demonstrated to either enhance or block infection in tissue-culture experiments. The work presented in this thesis aimed to characterize the expression and function of three cellular proteins; CD317, SAMHD1, and Siglec-1, that function as modulators of retroviral infection. In the first project, we investigated the in vivo expression pattern of the intrinsic immunity factor CD317 (BST-2, tetherin) in humans. CD317 restricts the release of enveloped viruses including HIV from infected cells. An additional proposed function for CD317 is as a selective target for immunotherapy of multiple myeloma, due to its apparently highly restricted expression on the surface of terminally differentiated B cells. To facilitate further studies of the biological functions, regulation, and therapeutic potential of CD317, we performed microarray-based expression profiling in 468 tissue samples from 25 healthy organs from more than 210 patients. CD317 protein could be detected in all organs investigated and in a number of specialized cell types, several of which are targeted in vivo by pathogenic viruses restricted by CD317 in tissue culture. We found limited co-expression of CD317 with the IFN biomarker MxA in vivo and low or no stimulation in organ explants exposed to recombinant IFNα, indicating that interferons may only partially regulate CD317. The study identified multiple thus far unknown interaction sites of viruses with CD317 and refutes the concept of its limited constitutive expression and strict IFN inducibility. Furthermore, CD317’s widespread expression questions its suitability as a target for immunotherapy. The second project involved characterizations of the restriction factor SAMHD1 in resting CD4+ T cells. SAMHD1 was reported to potently limit productive HIV-1 infection in a myeloid cell-specific manner by restricting HIV at the level of reverse transcription, and this block could be overcome by the Vpx protein of SIV and HIV-2. Our study demonstrated that SAMHD1 is also expressed abundantly in resting CD4+ T cells, where it locates to both the nucleus and cytoplasm. A staining protocol for SAMHD1 detection by flow cytometry was established, which enabled kinetic monitoring of its expression at a single cell level. Endogenous SAMHD1 levels were depleted in cells which either expressed Vpx following plasmid transfection or infection with Vpx-carrying HIV virions. In the latter case the restriction was alleviated, suggesting that reverse transcription is actively suppressed in resting CD4+ T cells, and that SAMHD1 is at least partly responsible for this restriction. The third project focused on the surface receptor Siglec-1 (sialoadhesin, CD169) that mediates trans-enhancement of HIV-1 infection through recognition of sialic acid moieties in virus membrane gangliosides. Our study demonstrated that mouse Siglec-1, expressed on macrophages, captures murine leukemia virus (MLV) particles and mediates their transfer to proliferating B- and T-lymphocytes. To investigate the interaction between Siglec-1 and virus and its importance for mediating trans-infection, we analyzed the potential of sialic acid precursor analogs to modulate the MLV/Siglec-1 interaction. MLV released from N-substituted D-mannosamine analog-pretreated cells displayed strikingly different capacities for Siglec-1-mediated capture and trans-infection. The N-acyl side chain of sialic acid was thus revealed as a critical functional determinant for the mouse Siglec-1-MLV interaction. In conclusion, the findings presented in this thesis provide new insights into the physiological expression pattern, regulation and function of the innate immunity factors CD317, SAMHD1 and Siglec-1. Characterizing the infection-modifying properties of these proteins might lead to a better understanding of their impact on retroviral spread and pathogenesis

    Terveysalan ammattikorkeakoulutuksen ohjaus

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    Projektityöskentely matematiikan opiskelussa ylÀkoululaisten ja heidÀn opettajiensa kokemana

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    Projektioppiminen on ongelmakeskeinen menetelmĂ€, jossa tavoitteena on oppiaineen sisĂ€ltöjen syvĂ€llisen ymmĂ€rryksen lisĂ€ksi työelĂ€mĂ€taitojen harjoittelu. Opetus pyrkii yhdistĂ€mÀÀn opiskeltavan aineen oppilaiden jokapĂ€ivĂ€iseen elĂ€mÀÀn tai tulevaan työelĂ€mÀÀn. TĂ€ssĂ€ tutkimuksessa tarkastelemme oppilaiden (N = 201) ja opettajien (N = 10) kokemuksia projektityöskentelystĂ€ ylĂ€koulun matematiikan tunneilla. Projektit tukivat oppilaiden ymmĂ€rrystĂ€ siitĂ€, missĂ€ matematiikkaa tarvitaan koulun ulkopuolella ja motivoivat erityisesti poikia matematiikan opiskeluun.  Projektioppiminen on ongelmakeskeinen menetelmĂ€, jossa tavoitteena on oppiaineen sisĂ€ltöjen syvĂ€llisen ymmĂ€rryksen lisĂ€ksi työelĂ€mĂ€taitojen harjoittelu. Opetus pyrkii yhdistĂ€mÀÀn opiskeltavan aineen oppilaiden jokapĂ€ivĂ€iseen elĂ€mÀÀn tai tulevaan työelĂ€mÀÀn. TĂ€ssĂ€ tutkimuksessa tarkastelemme oppilaiden (N = 201) ja opettajien (N = 10) kokemuksia projektityöskentelystĂ€ ylĂ€koulun matematiikan tunneilla. Projektit tukivat oppilaiden ymmĂ€rrystĂ€ siitĂ€, missĂ€ matematiikkaa tarvitaan koulun ulkopuolella ja motivoivat erityisesti poikia matematiikan opiskeluun. &nbsp

    HCI and UN's sustainable development goals:responsibilities, barriers and opportunities

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    Despite increasing interest, Sustainable HCI has been critiqued for doing too little, and perhaps also at times for doing the wrong things. Still, a field like Human-Computer Interaction should aim at being part of transforming our society into a more sustainable one. But how do we do that, and, what are we aiming for? With this workshop, we propose that HCI should start working with the new global Sustainable Development Goals (SDG) that were formally adopted by the UN in September 2015. How can Sustainable HCI be inspired by, and contribute to these goals? What should we in the field of HCI do more of, and what should we perhaps do less of? In what areas should we form partnerships in order to reach the Sustainable Development Goals and with whom should we partner

    The Futures of Computing and Wisdom

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    There has been an increasing interest in discussing the consequences of the technologies we invent and study in HCI. Whether it is climate change, ethical computing, capitalist and neo-liberal models of commerce and society, grassroots movements, big data or alternative paradigms in distributed systems, this workshop will invite participants to explore these consequences and ask how we move forward with responsibility and new forms of knowing and knowledge. We invite participants to join us, as we cast forward fifty years to 2068 to imagine the future of wisdom, and to reflect on how we got there. By writing Fictional Abstracts, an abstract from a research paper yet to be written, we will unpick critical tensions in the advancement of computing over the next decades. The workshop will develop perspectives on the futures of computing and critically reflect on the assumptions, methods, and tools for enabling (and disabling) such futures
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