362 research outputs found
Contribution à l'étude de la flore cryptogamique du canton du Valais: liste des récoltes faites du 16 au 20 juillet 1911 dans les environs de Sierre, de Viège et du Simplon, lors de la séance de la Murithienne à Viège
Activating health goals reduces (increases) hedonic evaluation of food brands for people who harbor highly positive (negative) affect toward them
Associations of pleasure and fun with junk foods have the potential to create considerable challenges for efforts to improve diets. The aim of this research was to determine whether activating health goals had the potential to exploit mixed motivations (i.e., health and pleasure) that people have related to food, and subsequently strip junk foods of the expected pleasure derived from them. In study 1, 98 participants evaluated a soft drink brand after being primed (not primed) for health. In study 2, 93 participants evaluated a presweetened breakfast cereal brand after being primed (not primed) for health. In both studies, participants who harbored highly positive feelings for the food brands devalued their hedonic judgments of them when they were primed for health. However, in an unexpected result, participants in both studies who harbored highly negative feelings for the food brands revalued their hedonic judgments of them (i.e., increased the favorability) when they were primed for health. Thus, increasing health salience is only effective in decreasing expected pleasure derived from junk foods for people who harbor positive affect toward junk food brands, and is likely counterproductive for people who harbor negative affect toward junk food brands
Herborisation mycologique en Valais à l'occasion de la réunion de la Murithienne, à Orsières, en 1915
Animal models for studying neural crest development: is the mouse different?
The neural crest is a uniquely vertebrate cell type and has been well studied in a number of model systems. Zebrafish, Xenopus and chick embryos largely show consistent requirements for specific genes in early steps of neural crest development. By contrast, knockouts of homologous genes in the mouse often do not exhibit comparable early neural crest phenotypes. In this Spotlight article, we discuss these species-specific differences, suggest possible explanations for the divergent phenotypes in mouse and urge the community to consider these issues and the need for further research in complementary systems
Differential Accessibility of a Hydrogenation Catalyst to Acyl Lipids in Thylakoid Membranes from Atrazine-Resistant and Susceptible Solarium nigrum Biotypes
The novel water-soluble palladium complex was used as a probe to test the acyl lipid molecular organization of liposomes and thylakoids originating from triazine-resistant (R) and -susceptible (S) lines of Solarium nigrum. In the present study we report on differing susceptibility of some defined lipid classes towards hydrogenation which shows alterations in the accessibility of the catalyst to lipid substrates within R- compared to S-membranes. Further evidence to support differences in membrane architecture of S- and R-type thylakoids was provided by the lifetime distribution analysis of diphenylhexatriene. The remarkable relative increase of pool size and width of a medium lifetime decay component (4 ns) in S-samples indicates a more diverse molecular organization of this membrane. For an apparently identical lipid class and fatty acid composition and fluidity of thylakoids, the greater environmental heterogeneity of the fluorophore in S-membranes may be attributed to stronger protein-lipid interactions. The possible existence of some intramembraneous domains of acyl lipids, some of which being relatively protected against the catalyst and present only in the atrazine-susceptible biotype, is discusse
Subalpine-nival gradient of species richness for vascular plants, bryophytes and lichens in the Swiss Inner Alps
In the European GLORIA project, 12 summits (treeline to nival belt) were inventoried in three regions of Switzerland: two in the Swiss National Park Graubünden and one in Valais. Vascular plants were recorded in all three regions and bryophytes and lichens were recorded only in Valais. On each summit, vegetation and temperature data were sampled using sampling protocols for the GLORIA project (Global Observation Research Initiative in Alpine environment) on large summit sections and in clusters of four 1×1-m quadrats. We observed a general decrease of species richness for all three systematic groups with increasing elevation in the summit sections, but only for vascular plants in the quadrats. In Valais, there was higher species richness for vascular plants than for bryophytes and lichens on the lower summits, but as the decrease in species richness was less pronounced for cryptogams, the latter were more numerous than vascular plants on the highest summit. Vascular species showed a clear shift of the dominant life form with elevation, with chamaephytes replacing hemicryptophytes. Bryophytes and lichens showed a weak trend among the life forms at the summit section scale, but a stronger shift of the dominant forms was seen in the quadrats, with cushion replacing turf bryophytes and crustaceous replacing fruticose lichens. Altogether, these results sustain the temperature-physiographic hypothesis to explain the species richness decrease along the altitudinal gradient: the harsh climatic conditions of the alpine-nival belts act as a filter for species, but the diminishing diversity of microhabitats is also an important factor. Because cryptogams depend more on humidity than temperature and more on smaller microhabitats than vascular plants, the decrease of species richness is more gradual with elevation for bryophytes and lichen
Marine nutrient subsidies promote biogeochemical hotspots in undisturbed, highly humic estuaries
The land-ocean dissolved organic carbon (DOC) flux represents a significant term within the global carbon budget, with peatland-dominated regions representing the most intense sources of terrestrial DOC export. As the interface between freshwater and marine systems, estuaries have the potential to act as a filter of the land-ocean carbon flux, removing terrestrially derived DOC, which is present at low concentrations in the oceans, via a combination of physicochemical and biological processes. However, the fate of peat-derived DOC within estuaries remains poorly quantified, partly due to the complicating influences of heterogeneous soils, land-use, point sources, and upstream modification of organic matter. To minimize these modifying factors, we studied DOC and inorganic nutrients in four small, peat-dominated, minimally disturbed, and oligotrophic Falkland Island estuaries. Contrary to expectations, we found limited evidence of physicochemical estuarine DOC removal, and instead observed apparent "hot zones" of biogeochemical activity, where terrestrially-derived silicate mixed with inorganic nitrogen and phosphorus entering the estuaries from the nutrient-rich marine ecosystem. In two estuaries, this coincided with apparent in situ DOC production. We suggest that the observed phenomena of marine nutrient subsidy of estuarine productivity, and flexible utilization of multiple nutrients within the oligotrophic system, may once have been widespread in temperate estuaries. However, this function has been lost in many ecosystems due to catchment eutrophication by agricultural and urban development. We conclude that the estuaries of the Falkland Islands provide a valuable pre-disturbance analogue for natural biogeochemical functioning in temperate estuaries receiving high organic matter inputs
A Second Giant Planet in 3:2 Mean-Motion Resonance in the HD 204313 System
We present 8 years of high-precision radial velocity (RV) data for HD 204313
from the 2.7 m Harlan J. Smith Telescope at McDonald Observatory. The star is
known to have a giant planet (M sin i = 3.5 M_J) on a ~1900-day orbit, and a
Neptune-mass planet at 0.2 AU. Using our own data in combination with the
published CORALIE RVs of Segransan et al. (2010), we discover an outer Jovian
(M sin i = 1.6 M_J) planet with P ~ 2800 days. Our orbital fit suggests the
planets are in a 3:2 mean motion resonance, which would potentially affect
their stability. We perform a detailed stability analysis, and verify the
planets must be in resonance.Comment: Accepted for publication in Ap
Prevalence of Plasmodium falciparum infection in asymptomatic rural Gabonese populations
<p>Abstract</p> <p>Background</p> <p>Malaria may be perennial or epidemic in sub-Saharan Africa, and its transmission may be stable or unstable, depending on the region. The prevalence of asymptomatic <it>Plasmodium falciparum </it>carriage is poorly documented in Gabon. A large survey of <it>P. falciparum </it>infection was conducted in asymptomatic individuals living in rural Gabon.</p> <p>Methods</p> <p>Two hundred and twenty-two villages were randomly selected in the nine administrative regions. With the participants' informed consent, blood samples were collected for thick and thin blood film examination after 20% Giemsa staining. Prevalence rates were calculated per village, per region and per ecosystem, and nationwide. Demographic risk factors were identified with STATA software version 9.0. Significance was assumed at p < 0.05.</p> <p>Results and discussion</p> <p>The prevalence of <it>P. falciparum </it>in adults was 6.2% (269/4342) nationwide, with a maximum of 37.2% in one village; a linear decrease was observed with increasing age (p = 0.045). Only 5% of the 399 children from forest areas tested positive. The prevalence was significantly higher in forest areas (7%) than in savannah (4%) and lakeland (2.5%). Within the forest region, the prevalence was significantly higher in forest grassland (10.9%) than in the mountain forest (3.5%), interior forest (6.8%) and north-eastern forest (4.5%).</p> <p>Conclusion</p> <p><it>Plasmodium falciparum </it>carriage remains high among adults in rural Gabon. Control measures must be adapted to the region and ecosystem. Routine treatment of asymptomatic individuals should be considered.</p
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