97 research outputs found

    The Useless Arctic: Exploiting Nature in the Arctic in the 1870s

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    What is the discursive genealogy of an ecological approach to the Arctic? Building on distinctions suggested by Francis Spufford and Gísli Pálsson, this article examines a specific juncture in the history of European–Arctic interaction – the reception of the Austro-Hungarian Arctic Expedition in 1874 – and traces the potential for ecological and relational understandings in what seems to be an orientalist and exploitative material. Examining the medial reception in Austria and in Norway, along with certain key texts in which Arctic wildlife is described, we find that the Norwegian reception of the expedition emphasizes practical issues connected with resource exploitation in the Arctic, while the Austrian reception mostly sees the Arctic as a symbolic resource with which to negotiate issues of identity and modernity. The Austrian discourse revolves around a set of paradoxical contradictions, the most central being those between materialism and idealism and emptiness and fullness; we argue it is the instability of such ambiguities which produces the possibility of a future ecological discourse

    Role of subsea permafrost and gas hydrate in postglacial Arctic methane releases

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    The papers of this thesis are not available in Munin.<br>Paper I: 'Offshore permafrost decay and massive seabed methane escape in water depths > 20 m at the South Kara Sea shelf.' Alexey Portnov, Andrew J. Smith, Jürgen Mienert, Georgy Cherkashov, Pavel Rekant, Peter Semenov, Pavel Serov, Boris Vanshtein. Available in <a href=http://dx.doi.org/10.1002/grl.50735> Geophysical Research Letters, vol. 40, 1–6</a><br>Paper II: 'Modeling the evolution of climate-sensitive Arctic subsea permafrost in regions of extensive gas expulsion at the West Yamal shelf.' Alexey Portnov, Jurgen Mienert, Pavel Serov. Available in <a href=http://dx.doi.org/10.1002/2014JG002685> Journal of Geophysical Research: Biogeosciences, vol. 119, issue 11, 2014</a> <br>Paper III: 'Methane release from pingo-like features across the South Kara Sea shelf, an area of thawing offshore permafrost'. Pavel Serov, Alexey Portnov, Jurgen Mienert, Peter Semenov, Polina Ilatovskaya. (Manuscript). Published version available in <a href=http://dx.doi.org/10.1002/2015JF003467> Journal of Geophysical Research: Earth Surface, vol. 120, issue 8, 2015</a> <br>Paper IV: 'Ice-sheet driven methane storage and release in the Arctic.' Alexey Portnov, Sunil Vadakkepulyambatta, Jurgen Mienert, Alun Hubbard. (Manuscript)Greenhouse gas methane is contained as gas hydrate, an icy structure, under the seabed in enormous amounts of Arctic regions. West Svalbard continental margin, which we investigated here, is one of these regions. Also, in the Russian Kara Sea the subsea permafrost is acting as a cap for the gas to be released in the future. But continuous expulsions of methane have been already observed in both places. This study shows how the subsea permafrost in the Kara Sea, and gas hydrate systems offshore West Svalbard, have evolved from the last ice age to the present day. The conclusions are based on integrated field geophysical and gas-geochemical studies as well as modeling of permafrost, gas hydrate reservoirs and Barents Sea ice sheet dynamics. It shows that continuous permafrost of the Kara Sea is more fragile than previously thought. It is likely to be limited to the shallow water depths of 20 meters on this Arctic shelf region, allowing expulsions of methane from an area of 7500 sq km. Offshore Svalbard almost 2000 active and inactive gas expulsion sites are associated with melting of gas hydrate and thawing of shallow permafrost from past to present. Our research approach shows that natural climate drivers such as methane release can change and that they are connected to the ice sheet retreat since the last ice age. These processes triggered widespread seafloor gas discharge, observed in Arctic shelf and upper continental margins to this day

    Vetenskaplig expertis och nordområdets naturresurser

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    The essay reflects on political pressures exerted by and on scientists and technologists acting as advisors on political and economic matters of the high north.It uses two case studies to do this. One consists in the group of scientists from several nations who engaged as advisors to their foreign offices in the process leading up tothe ratification of the Spitsbergen/Svalbard treaty in 1920. The focus is on the discourse regarding hunting, mining and nature protections on these islands. The second case is the way technologists and geological scientists were engaged in the industrialisation of the USSR. These contexts of course differ in scale and in many other ways but are similar in certain respects. The discussion is centred on the problems of technocracy which is commented based on the Frankfurt school's elaborations on the open society and differing interpretations of technological determinism. This is related further to contemporary contentions over the balance between scientific based environmental stewardship and technological management in northern raw material extraction

    Structure-activity relationships of the antimicrobial peptide arasin 1 - and mode of action studies of the N terminal, proline-rich region

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    Arasin 1 is a 37 amino acid long proline-rich antimicrobial peptide isolated from the spider crab, Hyas araneus. In this work the active region of arasin 1 was identified through structure-activity studies using different peptide fragments derived from the arasin 1 sequence. The pharmacophore was found to be located in the proline/arginine-rich NH2 terminus of the peptide and the fragment arasin 1(1–23) was almost equally active to the full length peptide. Arasin 1 and its active fragment arasin 1(1–23) were shown to be non-toxic to human red blood cells and arasin 1(1–23) was able to bind chitin, a component of fungal cell walls and the crustacean shell. The mode of action of the fully active N-terminal arasin 1(1–23) was explored through killing kinetic and membrane permeabilization studies. At the minimal inhibitory concentration (MIC), arasin 1(1–23) was not bactericidal and had no membrane disruptive effect. In contrast, at concentrations of 5×MIC and above it was bactericidal and interfered with membrane integrity. We conclude that arasin 1(1–23) has a different mode of action than lytic peptides, like cecropin P1. Thus, we suggest a dual mode of action for arasin 1(1–23) involving membrane disruption at peptide concentrations above MIC, and an alternative mechanism of action, possibly involving intracellular targets, at MIC

    Modification of sunlight radiation through colored photo-selective nets affects anthocyanin profile in Vaccinium spp. berries

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    <p>Objectives In recent years, the interest on the effects of the specific wavelengths of the light spectrum on growth and metabolism of plants has been increasing markedly. The present study covers the effect of modified sunlight conditions on the accumulation of anthocyanin pigments in two Vaccinium species: the European wild bilberry (V. myrtillus L.) and the cultivated highbush blueberry (V. corymbosum L.). <p>Methods The two Vaccinium species were grown in the same test field in the Alps of Trentino (Northern Italy) under modified light environment. The modification of sunlight radiation was carried out in field, through the use of colored photo-selective nets throughout the berry ripening during two consecutive growing seasons. The anthocyanin profile was then assessed in berries at ripeness. <p>Results The results indicated that the light responses of the two Vaccinium species studied were different. Although both studied species are shade-adapted plants, 90% shading of sunlight radiation was beneficial only for bilberry plants, which accumulated the highest content of anthocyanins in both seasons. The same condition, instead, was not favorable for blueberries, whose maturation was delayed for at least two weeks, and anthocyanin accumulation was significantly decreased compared to berries grown under sunlight conditions. Moreover, the growing season had strong influence on the anthocyanin accumulation in both species, in relation to temperature flow and sunlight spectra composition during the berry ripening period. <p>Conclusions Our results suggest that the use of colored photo-selective nets may be a complementary agricultural practice for cultivation of Vaccinium species. However, further studies are needed to analyze the effect of the light spectra modifications to other nutritional properties, and to elucidate the molecular mechanisms behind the detected differences between the two relative Vaccinium species

    Epidemiology of eating disorders part III: Social epidemiology and case definitions revisited.

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    Accepted manuscript version. Published version at <a href=http://doi.org/10.1080/21662630.2015.1022197>http://doi.org/10.1080/21662630.2015.1022197</a>.The previous papers in this series outlined a historical panorama and presented updated knowledge about putative risk factors and how eating disorders are distributed in various populations. In this final paper, we discuss in what way comorbidity findings and transdiagnostic issues may change our conceptions about ‘an epidemiological case’ from the current definition of eating disorders based on the recent version of the Diagnostic and Statistical Manual of Mental Disorders (i.e. the DSM-5), and to what extent an alternative definition may introduce new perspectives of prevention. The paper also provides an update on issues relevant for treatment dissemination

    Factors associated with adherence to antiretroviral therapy in HIV-infected patients in Kathmandu District, Nepal

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    <p><b>Copyright information:</b></p><p>Taken from "Association of oestrogen receptor beta 2 (ERβ2/ERβcx) with outcome of adjuvant endocrine treatment for primary breast cancer – a retrospective study"</p><p>http://www.biomedcentral.com/1471-2407/7/131</p><p>BMC Cancer 2007;7():131-131.</p><p>Published online 18 Jul 2007</p><p>PMCID:PMC1950511.</p><p></p>ses) and dichotomised levels of ERβ2 mRNA in the ERα + tamoxifen-treated cohort and (B, 4 events in 29 ERβ2 high cases and 12 events in 29 ERβ2 low cases). Unbroken green lines represent cases with high levels of ERβ2, dotted blue lines represent cases with low levels. In all cases crosses represent censored data and P values are given for Log Rank tests

    On the measurement of subsonic flow in a capacitively coupled helicon plasma source

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    Plasma parameters and the subsonic flow from a capacitively coupled, cylindrical plasma source of the Njord helicon device are investigated by means of a Mach probe and a retarding field energy analyzer (RFEA). 13.56 MHz and 600 W RF power is inserted into the argon working gas under low-pressure conditions and moderate magnetic field. By means of a downstream field coil, the magnetic field is shaped from a purely expanding field to a configuration with more parallel field lines. It is shown that the downstream plasma density along the outer rim of the source increases significantly and there is a sudden increase by nearly 20 V in the plasma potential already after a moderate increase in the downstream magnetic field. The investigation of the flow indicates that current ratios derived from the Mach probe result in an apparent flow in the direction towards the source, while the current bratios derived from the RFEA indicate a flow in the direction away from the source. PIC simulations demonstrate that the acceptance angle of the probes, being nearly 180o for the Mach probe, and about 45o for the RFEA, can critically affect the current ratios and hence the subsonic flow measured by the probes in the weakly magnetized plasma in our device. The first section in your pape

    Mobility and Conflict

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    Accepted manuscript version. Published version at <a href=http://doi.org/10.1257/mic.20130055>http://doi.org/10.1257/mic.20130055</a>.We study the role of intergroup mobility in the emergence of conflict. Two groups compete for the right to allocate society's resources. We allow for costly intergroup mobility. The winning group offers an allocation, which the opposition can accept or reject, and wage conflict. Agents can also switch group membership. Expropriating a large share of resources increases political strength by attracting opposition members, but implies a higher threat of conflict. Our main finding is that the possibility of intergroup mobility affects the likelihood of conflict in a nonmonotonic way. Open conflict can arise at intermediate costs of mobility. (JEL D71, D72, D74
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