57 research outputs found

    Sandeels in the diets of seals: application of novel and conventional methods of analysis to faeces from seals in the Moray Firth area of Scotland

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    Serological methods for prey identification have been applied to detection of residues ofsandeel (Ammodytidae) protein in faeces of common seals (Phoca vitulina) and grey seals(Halichoerus grypus) from the Moray Firth, north-east Scotland. Antisera raised to muscleprotein from Ammodytes marinus were evaluated by testing their reactions with proteinextracts made from a range of North Sea fish species and protein residues in in vitro digestates,seal digestive tracts and seal faeces. It was concluded that, using fused rocketimmuno-electrophoresis, linkage of precipitin peaks from unknown samples with peaksfrom standard sandeel extract was a reliable indicator of the presence of sandeel in theunknown sample. Seasonal variation in the incidence of sandeels in common seal diet in theMoray Firth was examined by identifying otoliths, bones, and proteins, and all threemethods indicated that sandeels occurred in the majority of samples tested in the summer,but were less important during the winter. Proteins were detected in fewer samples thanotoliths, particularly in February and March. Possible reasons for this difference arediscussed. Serological identification of sandeel proteins is potentially applicable to dietarystudies on all marine predators

    Implications of farmer perceived production constraints and varietal preferences to pearl millet breeding in Senegal

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    Pearl millet ( Pennisetum glaucum L.) plays a critical role in smallholder food security in sub-Saharan Africa. The production of pearl millet has, however, stagnated or even declined due to several factors. The objective of this study was to assess farmer perceptions on production constraints and varietal preferences in Senegal. A survey was conducted involving 150 randomly selected farmers from 15 villages, in five representative rural communities of Senegal. A semi-structured questionnaire was used, supplemented by focus group discussions. Results revealed that parasitic Striga weed was the most constraining factor to pearl millet production across the rural communes. This was followed by low soil fertility and insect pests in that order. Other constraints included lack of machinery for sowing, plant diseases, drought, seed-eating birds, limited access to land for pearl millet cultivation and limited seed availability. Among the traits for varietal preference, farmers unanimously considered grain yield as the most important trait. Other important traits mentioned were adaptation to drought, adaptation to low soil fertility and earliness. These production constraints and varietal preference should be integrated in the profile of the national pearl millet breeding programmes in order to improve the productivity and adoption of bred-cultivars.Le mil est une importante culture c\ue9r\ue9ali\ue8re et joue un r\uf4le essentiel dans la s\ue9curit\ue9 alimentaire de la plupart des producteurs de l\u2019Afrique subsaharienne. Cependant, la production est oscillante et faible en raison de plusieurs facteurs. Une \ue9tude a \ue9t\ue9 conduite pour \ue9valuer la perception des producteurs sur les contraintes limitant la production du mil et leurs pr\ue9f\ue9rences vari\ue9tales au S\ue9n\ue9gal. Une enqu\ueate avec150 producteurs s\ue9lectionn\ue9s al\ue9atoirement a \ue9t\ue9 men\ue9e dans 15 villages situ\ue9s dans cinq communaut\ue9s rurales du S\ue9n\ue9gal. Une \ue9valuation rurale participative et des enqu\ueates ont \ue9t\ue9 men\ue9es. Les r\ue9sultats ont montr\ue9 que le Striga est le facteur majeur qui limite la production de mil au niveau des diff\ue9rentes communaut\ue9s rurales. Les autres contraintes rencontr\ue9es dans les communes rurales \ue9taient le manque de machines pour le semis, les maladies, la s\ue9cheresse, les oiseaux granivores, l\u2019acc\ue8s limit\ue9 \ue0 la terre et la faible disponibilit\ue9 des semences de vari\ue9t\ue9s am\ue9lior\ue9es. Les producteurs ont unanimement consid\ue9r\ue9 le rendement en grains comme le trait le plus important dans le choix d\u2019une nouvelle vari\ue9t\ue9. Les autres traits jug\ue9s important sont l\u2019adaptation \ue0 la s\ue9cheresse l\u2019adaptation \ue0 la faible fertilit\ue9 des sols et la pr\ue9cocit\ue9. Ces contraintes de production et pr\ue9f\ue9rences vari\ue9tales doivent \ueatre incluses parmi les objectifs du programme national de s\ue9lection de mil pour am\ue9liorer la productivit\ue9 et le taux l\u2019adoption des nouvelles vari\ue9t\ue9s

    Traits associated with innate and adaptive immunity in pigs: heritability and associations with performance under different health status conditions

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    There is a need for genetic markers or biomarkers that can predict resistance towards a wide range of infectious diseases, especially within a health environment typical of commercial farms. Such markers also need to be heritable under these conditions and ideally correlate with commercial performance traits. In this study, we estimated the heritabilities of a wide range of immune traits, as potential biomarkers, and measured their relationship with performance within both specific pathogen-free (SPF) and non-SPF environments. Immune traits were measured in 674 SPF pigs and 606 non-SPF pigs, which were subsets of the populations for which we had performance measurements (average daily gain), viz. 1549 SPF pigs and 1093 non-SPF pigs. Immune traits measured included total and differential white blood cell counts, peripheral blood mononuclear leucocyte (PBML) subsets (CD4+ cells, total CD8α+ cells, classical CD8αÎČ+ cells, CD11R1+ cells (CD8α+ and CD8α-), B cells, monocytes and CD16+ cells) and acute phase proteins (alpha-1 acid glycoprotein (AGP), haptoglobin, C-reactive protein (CRP) and transthyretin). Nearly all traits tested were heritable regardless of health status, although the heritability estimate for average daily gain was lower under non-SPF conditions. There were also negative genetic correlations between performance and the following immune traits: CD11R1+ cells, monocytes and the acute phase protein AGP. The strength of the association between performance and AGP was not affected by health status. However, negative genetic correlations were only apparent between performance and monocytes under SPF conditions and between performance and CD11R1+ cells under non-SPF conditions. Although we cannot infer causality in these relationships, these results suggest a role for using some immune traits, particularly CD11R1+ cells or AGP concentrations, as predictors of pig performance under the lower health status conditions associated with commercial farms

    Preliminary outcomes of a paediatric highly active antiretroviral therapy cohort from KwaZulu-Natal, South Africa

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    BACKGROUND: Few studies address the use of paediatric highly active antiretroviral therapy (HAART) in Africa. METHODS: We performed a retrospective cohort study to investigate preliminary outcomes of all children eligible for HAART at Sinikithemba HIV/AIDS clinic in KwaZulu-Natal, South Africa. Immunologic, virologic, clinical, mortality, primary caregiver, and psychosocial variables were collected and analyzed. RESULTS: From August 31, 2003 until October 31, 2005, 151 children initiated HAART. The median age at HAART initiation was 5.7 years (range 0.3–15.4). Median follow-up time of the cohort after HAART initiation was 8 months (IQR 3.5–13.5). The median change in CD4% from baseline (p < 0.001) was 10.2 (IQR 5.0–13.8) at 6 months (n = 90), and 16.2 (IQR 9.6–20.3) at 12 months (n = 59). Viral loads (VLs) were available for 100 children at 6 months of which 84% had HIV-1 RNA levels ≀ 50 copies/mL. At 12 months, 80.3% (n = 61) had undetectable VLs. Sixty-five out of 88 children (73.8%) reported a significant increase (p < 0.001) in weight after the first month. Eighty-nine percent of the cohort (n = 132) reported ≀ 2 missed doses during any given treatment month (> 95%adherence). Seventeen patients (11.3%) had a regimen change; two (1.3%) were due to antiretroviral toxicity. The Kaplan-Meier one year survival estimate was 90.9% (95%confidence interval (CI) 84.8–94.6). Thirteen children died during follow-up (8.6%), one changed service provider, and no children were lost to follow-up. All 13 deaths occurred in children with advanced HIV disease within 5 months of treatment initiation. In multivariate analysis of baseline variables against mortality using Cox proportional-hazards model, chronic gastroenteritis was associated with death [hazard ratio (HR), 12.34; 95%CI, 1.27–119.71) and an HIV-positive primary caregiver was found to be protective against mortality [HR, 0.12; 95%CI, 0.02–0.88). Age, orphanhood, baseline CD4%, and hemoglobin were not predicators of mortality in our cohort. Fifty-two percent of the cohort had at least one HIV-positive primary caregiver, and 38.4% had at least one primary caregiver also on HAART at Sinikithemba clinic. CONCLUSION: This report suggests that paediatric HAART can be effective despite the challenges of a resource-limited setting

    European Red List of Habitats Part 2. Terrestrial and freshwater habitats

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    Towards a microbial process-based understanding of the resilience of peatland ecosystem service provisioning – a research agenda

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    Peatlands are wetland ecosystems with great significance as natural habitats and as major global carbon stores. They have been subject to widespread exploitation and degradation with resulting losses in characteristic biota and ecosystem functions such as climate regulation. More recently, large-scale programmes have been established to restore peatland ecosystems and the various services they provide to society. Despite significant progress in peatland science and restoration practice, we lack a process-based understanding of how soil microbiota influence peatland functioning and mediate the resilience and recovery of ecosystem services, to perturbations associated with land use and climate change. We argue that there is a need to: in the short-term, characterise peatland microbial communities across a range of spatial and temporal scales and develop an improved understanding of the links between peatland habitat, ecological functions and microbial processes; in the medium term, define what a successfully restored ’target’ peatland microbiome looks like for key carbon cycle related ecosystem services and develop microbial-based monitoring tools for assessing restoration needs; and in the longer term, to use this knowledge to influence restoration practices and assess progress on the trajectory towards ‘intact’ peatland status. Rapid advances in genetic characterisation of the structure and functions of microbial communities offer the potential for transformative progress in these areas, but the scale and speed of methodological and conceptual advances in studying ecosystem functions is a challenge for peatland scientists. Advances in this area require multidisciplinary collaborations between peatland scientists, data scientists and microbiologists and ultimately, collaboration with the modelling community. Developing a process-based understanding of the resilience and recovery of peatlands to perturbations, such as climate extremes, fires, and drainage, will be key to meeting climate targets and delivering ecosystem services cost effectively

    Limited Vegetation Development on a Created Salt Marsh Associated with Over-Consolidated Sediments and Lack of Topographic Heterogeneity

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    Restored salt marshes frequently lack the full range of plant communities present on reference marshes, with upper marsh species underrepresented. This often results from sites being too low in the tidal frame and/or poorly drained with anoxic sediments. A managed coastal realignment scheme at Abbotts Hall, Essex, UK, has oxic sediments at elevations at which upper marsh communities would be expected. But 7 years after flooding, it continued to be dominated by pioneer communities, with substantial proportions of bare ground, so other factors must hinder vegetation development at these elevations. The poorly vegetated areas had high sediment shear strength, low water and organic carbon content and very flat topography. These characteristics occur frequently on the upper parts of created marshes. Experimental work is required to establish causal links with the ecological differences, but other studies have also reported that reduced plant ÎČ-diversity and lower usage by fish are associated with topographic uniformity. Uniformity also leads to very different visual appearance from natural marshes. On the upper intertidal, sediment deposition rate are slow, water velocities are low and erosive forces are weak. So, topographic heterogeneity cannot develop naturally, even if creeks have been excavated. Without active management, these conditions will persist indefinitely
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