11 research outputs found
Habitat quality influences population distribution, individual space use and functional responses in habitat selection by a large herbivore
Identifying factors shaping variation in resource selection is central for our understanding of the behaviour and distribution of animals. We examined summer habitat selection and space use by 108 Global Positioning System (GPS)-collared moose in Norway in relation to sex, reproductive status, habitat quality, and availability. Moose selected habitat types based on a combination of forage quality and availability of suitable habitat types. Selection of protective cover was strongest for reproducing females, likely reflecting the need to protect young. Males showed strong selection for habitat types with high quality forage, possibly due to higher energy requirements. Selection for preferred habitat types providing food and cover was a positive function of their availability within home ranges (i.e. not proportional use) indicating functional response in habitat selection. This relationship was not found for unproductive habitat types. Moreover, home ranges with high cover of unproductive habitat types were larger, and smaller home ranges contained higher proportions of the most preferred habitat type. The distribution of moose within the study area was partly related to the distribution of different habitat types. Our study shows how distribution and availability of habitat types providing cover and high-quality food shape ungulate habitat selection and space use
Molecular Characterization of HIV-1 CRF01_AE in Mekong Delta, Vietnam, and Impact of T-Cell Epitope Mutations on HLA Recognition (ANRS 12159)
To date, 11 HIV-1 subtypes and 48 circulating recombinant forms have been described worldwide. The underlying reason why their distribution is so heterogeneous is not clear. Host genetic factors could partly explain this distribution. The aim of this study was to describe HIV-1 strains circulating in an unexplored area of Mekong Delta, Vietnam, and to assess the impact of optimal epitope mutations on HLA binding.We recruited 125 chronically antiretroviral-naive HIV-1-infected subjects from five cities in the Mekong Delta. We performed high-resolution DNA typing of HLA class I alleles, sequencing of Gag and RT-Prot genes and phylogenetic analysis of the strains. Epitope mutations were analyzed in patients bearing the HLA allele restricting the studied epitope. Optimal wild-type epitopes from the Los Alamos database were used as reference. T-cell epitope recognition was predicted using the immune epitope database tool according to three different scores involved in antigen processing (TAP and proteasome scores) and HLA binding (MHC score). with a Vietnamese specificity held by two different haplotypes. The percentage of homology between Mekong and B consensus HIV-1 sequences was above 85%. Divergent epitopes had TAP and proteasome scores comparable with wild-type epitopes. MHC scores were significantly lower in divergent epitopes with a mean of 2.4 (±0.9) versus 2 (±0.7) in non-divergent ones (p<0.0001).Our study confirms the wide predominance of CRF01_AE in the Mekong Delta where patients harbor a specific HLA pattern. Moreover, it demonstrates the lower MHC binding affinity among divergent epitopes. This weak immune pressure combined with a narrow genetic diversity favors immune escape and could explain why CRF01_AE is still predominant in Vietnam, particularly in the Mekong area
Tankyrase inhibition sensitizes melanoma to PD-1 immune checkpoint blockade in syngeneic mouse models
publishedVersio
Boom and bust of a moose population – a call for integrated forest management
This is the postprint version of the article. The published article can be located at www.springerlink.comThere is increasing pressure to manage forests
for multiple objectives, including ecosystem services and
biodiversity, alongside timber production. However, few
forests are currently co-managed for timber and wildlife,
despite potential economic and conservation benefits. We
present empirical data from a commercial Norway spruce
(
Picea abies
) and Scots pine (
Pinus sylvestris
) production
system in southern Norway in which moose (
Alces alces
)
are an important secondary product. Combining long-term
hunting and forestry records, we identified temporal vari-
ation in clear-felling over the past five decades, peaking in
the 1970s. Herbicide treatment of regenerating stands and a
fivefold increase in moose harvest has lead to a reduction in
availability of successional forest per moose of
[
90 %
since the 1960s. Field estimates showed that spraying with
the herbicide glyphosate reduced forage availability by 60
and 96 % in summer and winter, respectively, 4 years after
treatment. It also reduced moose use and habitat selection
of young spruce stands compared with unsprayed stands.
Together these lines of evidence suggest that forest man-
agement led to an increase in moose carrying capacity
during the 1970s and a subsequent decline thereafter. This
is likely to have contributed to observed reductions in moose population productivity in southern Norway and is
counter to sustainable resource management. We therefore
call for better integration and long-term planning between
forestry and wildlife management to minimise forest
damage and the development of large fluctuations in
ungulate populations
Asynchronous vegetation phenology enhances winter body condition of a large mobile herbivore
Integrated approach for pavement deterioration assessments in a low latitude crystalline basement of south-western Nigeria
Bioavailability and Bioaccessibility of Hydrophobic Organic Contaminants in Soil and Associated Desorption-Based Measurements
Many publications on contaminant bioavailability in soils often state that the use of total contaminant concentrations in risk assessment is an overly conservative approach. Such conservatism makes traditional risk assessment approaches and contaminated land decision-making expensive. The risk-based approach to contaminated land management strives to identify and manage the potential risks of significant harm being caused to humans and ecological receptors, following exposure to contaminated land. Risk-based approaches are more cost-effective than the traditional approaches from the perspective of contaminated land management. Contaminant bioavailability or bioaccessibility is one of the critical concepts that underpins risk-based approaches to contaminated land management. Bioavailability describes the fraction of the total contaminant concentration that desorbs from soil and is immediately available to cause harm to a living organism, after passing through the organism’s membrane. Bioaccessibility describes what is available and potentially available under natural environmental conditions and during realistic timeframes. The reliable measurements of either contaminant bioavailability or bioaccessibility is therefore critical; in this regard, a thorough understanding of contaminant sequestration and desorption behaviour is required. This chapter discusses the fate of HOCs in soils, bioavailability and bioaccessibility of organic contaminants and their associated desorption-based measurements