585 research outputs found

    Origin and phylogenetic status of the local Ashanti Dwarf pig (ADP) of Ghana based on genetic analysis.

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    BACKGROUND: The Ashanti Dwarf Pig (ADP) of Ghana is an endangered pig breed with hardy and disease resistant traits. Characterisation of animal genetic resources provides relevant data for their conservation and sustainable use for food security and economic development. We investigated the origin and phylogenetic status of the local ADP of Ghana and their crosses with modern commercial breeds based on mtDNA, MC1R, Y-chromosome sequence polymorphisms, and genome-wide SNP genotyping. RESULTS: The study involved 164 local pigs sampled from the three agro-ecological zones of Ghana. Analyses of the mitochondrial D-loop region and Y-chromosome sequences revealed both European and Asian genetic signatures, with differences between the geographical zones. Black coat colour is the most predominant within the breed, with black MC1R alleles of both Asian and European origin. European alleles for spotting are present at a low frequency in the sample set, and may account for the occurrence of spotted piglets in some APD litters. PCA analysis of SNP data revealed a strong location and breed effect on clustering of local Ghanaian pigs. On a global level, Ghanaian local pigs cluster closely with European pigs of commercial origin, but we identified intervals via FST analyses that may elucidate loci for ADP specific traits. CONCLUSIONS: The presence of both European and Asian contributions, with differences between geographical zones probably reflects trading and colonial influences. Understanding the effects of admixture on important adaptive and economic traits of the ADP and other local breeds in Africa is critical for developing sustainable conservation programmes to prevent the decline of these genetic resources.The authors are grateful to Cambridge in Africa Research Excellence (CAPREx) for the award of Post-doctoral Fellowship to ROA, and the Alborada Trust for supporting the Research. G.L is supported by the European Research Council (337574-UNDEAD), and BMS is supported by BBSRC grant number BB/N000129/1. CAS is funded by the Department of Pathology and Hughes Hall, Cambridge

    Dynamics of filaments and membranes in a viscous fluid

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    Motivated by the motion of biopolymers and membranes in solution, this article presents a formulation of the equations of motion for curves and surfaces in a viscous fluid. We focus on geometrical aspects and simple variational methods for calculating internal stresses and forces, and we derive the full nonlinear equations of motion. In the case of membranes, we pay particular attention to the formulation of the equations of hydrodynamics on a curved, deforming surface. The formalism is illustrated by two simple case studies: (1) the twirling instability of straight elastic rod rotating in a viscous fluid, and (2) the pearling and buckling instabilities of a tubular liposome or polymersome.Comment: 26 pages, 12 figures, to be published in Reviews of Modern Physic

    Hope and trust in times of Zika: the views of caregivers and healthcare workers at the forefront of the epidemic in Brazil.

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    This article investigates how hope and trust played out for two groups at the forefront of the Zika epidemic: caregivers of children with congenital Zika syndrome and healthcare workers. We conducted 76 in-depth interviews with members of both groups to examine hope and trust in clinical settings, as well as trust in public institutions, in the health system and in the government of Brazil. During and after the Zika epidemic, hope and trust were important to manage uncertainty and risk, given the lack of scientific evidence about the neurological consequences of Zika virus infection. The capacity of healthcare workers and caregivers to trust and to co-create hope seems to have allowed relationships to develop that cushioned social impacts, reinforced adherence to therapeutics and enabled information flow. Hope facilitated parents to trust healthcare workers and interventions. Hope and trust appeared to be central in the establishment of support networks for caregivers. At the same time, mistrust in the government and state institutions may have allowed rumours and alternative explanations about Zika to spread. It may also have strengthened activism in mother's associations, which seemed to have both positive and negative implications for healthcare service delivery. The findings also point to distrust in international health actors and global health agenda, which can impact community engagement in future outbreak responses in Brazil and other countries in Latin America

    2-Amino-4,5,6,7-tetra­hydro­benzo[b]thio­phene-3-carbonitrile

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    The title compound, C9H10N2S, was synthesized according to Gewald procedures by the reaction of cyclo­hexa­none with malonitrile and sulfur in the presence morpholine. The cyclo­hexane ring adopts a half-chair conformation and the thio­phene ring is essentially planar (r.m.s. deviation = 0.05 Å). The crystal packing is stabilized by two inter­molecular N—H⋯N hydrogen bonds, which link the mol­ecules into centrosymmetric rings with graph-set motif R 2 2(12)

    X-ray absorption spectroscopy study of diluted magnetic semiconductors: Zn1-xMxSe (M = Mn, Fe, Co) and Zn1-xMnxY (Y = Se, Te)

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    We have investigated 3d electronic states of doped transition metals in II-VI diluted magnetic semiconductors, Zn1-xMxSe (M = Mn, Fe, Co) and Zn1-xMnxY (Y = Se, Te), using the transition-metal L2,3-edge X-ray absorption spectroscopy (XAS) measurements. In order to explain the XAS spectra, we employed a tetragonal cluster model calculation, which includes not only the full ionic multiplet structure but also configuration interaction (CI). The results show that CI is essential to describe the experimental spectra adequately, indicating the strong hybridization between the transition metal 3d and the ligand p orbitals. In the study of Zn1-xMnxY (Y = Se, Te), we also found considerable spectral change in the Mn L2,3-edge XAS spectra for different ligands, confirming the importance of the hybridization effects in these materials.Comment: This paper consists of 22 pages including 4 figures. This paper is submitted to Physical Review
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