102 research outputs found

    Single-cell RNA sequencing of liver fine-needle aspirates captures immune diversity in the blood and liver in chronic hepatitis B patients

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    Background and Aims: HBV infection is restricted to the liver, where it drives exhaustion of virus-specific T and B cells and pathogenesis through dysregulation of intrahepatic immunity. Our understanding of liver-specific events related to viral control and liver damage has relied almost solely on animal models, and we lack useable peripheral biomarkers to quantify intrahepatic immune activation beyond cytokine measurement. Our objective was to overcome the practical obstacles of liver sampling using fine-needle aspiration and develop an optimized workflow to comprehensively compare the blood and liver compartments within patients with chronic hepatitis B using single-cell RNA sequencing. Approach and Results: We developed a workflow that enabled multi-site international studies and centralized single-cell RNA sequencing. Blood and liver fine-needle aspirations were collected, and cellular and molecular captures were compared between the Seq-Well S3 picowell-based and the 10× Chromium reverse-emulsion droplet–based single-cell RNA sequencing technologies. Both technologies captured the cellular diversity of the liver, but Seq-Well S3 effectively captured neutrophils, which were absent in the 10× dataset. CD8 T cells and neutrophils displayed distinct transcriptional profiles between blood and liver. In addition, liver fine-needle aspirations captured a heterogeneous liver macrophage population. Comparison between untreated patients with chronic hepatitis B and patients treated with nucleoside analogs showed that myeloid cells were highly sensitive to environmental changes while lymphocytes displayed minimal differences. Conclusions: The ability to electively sample and intensively profile the immune landscape of the liver, and generate high-resolution data, will enable multi-site clinical studies to identify biomarkers for intrahepatic immune activity in HBV and beyond.</p

    The value of manure - Manure as co-product in life cycle assessment

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    Research ArticleLivestock production is important for food security, nutrition, and landscape maintenance, but it is associated with several environmental impacts. To assess the risk and benefits arising from livestock production, transparent and robust indicators are required, such as those offered by life cycle assessment. A central question in such approaches is how environmental burden is allocated to livestock products and to manure that is re-used for agricultural production. To incentivize sustainable use of manure, it should be considered as a co-product as long as it is not disposed of, or wasted, or applied in excess of crop nutrient needs, in which case it should be treated as a waste. This paper proposes a theoretical approach to define nutrient requirements based on nutrient response curves to economic and physical optima and a pragmatic approach based on crop nutrient yield adjusted for nutrient losses to atmosphere and water. Allocation of environmental burden to manure and other livestock products is then based on the nutrient value from manure for crop production using the price of fertilizer nutrients. We illustrate and discuss the proposed method with two case studiesinfo:eu-repo/semantics/publishedVersio

    Transnational Investments of the Tunisian Diaspora: Trajectories, Skills Accumulation and Constraints

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    This chapter is based on recent empirical data on Tunisians living in Switzerland. It focuses on their migration pathways and experiences, and it examines their propensity to engage in entrepreneurial and business activities in their home country. Despite the hopes generated by the revolution of 2011, there are many people in Tunisia, especially young males from disadvantaged regions, who have not enjoyed the positive changes in employment opportunities and professional prospects. This has led them to them emigrate to Europe to ensure an income for themselves and their families back in Tunisia. An online survey accompanied by follow-up interviews enabled us to observe the experiences of Tunisian diaspora entrepreneurs and their current and potential future transnational business and investment activities. This chapter shows how the internationalization and accumulation of networks and skills by Tunisians, resulting from the multiple destinations they traversed before arriving to Switzerland, has influenced their professional capacities and their business and entrepreneurial projects in Tunisia. Tunisians feel a strong motivation to contribute to the development process in their home country, and they tend to invest and open businesses in their villages of origin. Several enablers and obstacles that influence their actions are observed. A number of policy recommendations based on the experiences and aspirations of these Tunisians are included in the conclusions

    Genetic characterization of Malawian cowpea (Vigna unguiculata (L.) Walp) landraces: diversity and gene flow among accessions

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    Cowpea has been cultured from ancient times in Africa and Asia and is now wide spread throughout the tropics and subtropics.Cowpea accessions can be distinguished phenotypically from one another by their growth habit, time to maturity, yield, and seed size and colour. Data on genetic diversity of farmer-developed accessions are lacking. The main objective of this study was to determine the pattern and extend of RAPD marker variation within and among cowpea populations from different agroecological zones and to determine the degree of genetic relationships and gene flow among different landraces used by local farmers. Twenty of the 30 RAPD primers tested allowed amplifications of random polymorphic (RAPD) loci. Overall,80% of the scored loci were polymorphic. The degree of band sharing was used to evaluate genetic distance between accessions and to construct a phylogenetic tree. The genetic distance values among accessions varied between 0.09 to 0.57.Although some small clusters grouped accessions of the same growth habits, a general lack of agreement between clustering and morphological features was observed. The analysis of molecular variance revealed that within-region or types (among accessions) variation accounted for 96% of the total molecular variance. This high within-accession variability is being sustained by an uncontrolled gene flow among populations
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