1,866 research outputs found

    Nitrogen and Fiber Digestion in Sheep Fed Fresh-Frozen and Field-Dried High and Low Tannin Sericea Lespedeza

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    Field-drying reduces extractable condensed tannin (CT) of sericea lespedeza [Lespedeza cuneata (Dum-Cours) G. Don], but effects on specific bound and unbound forms of CT and the relationship to protein and fiber digestion in ruminants are unclear. Intake and digestibility of fresh-frozen and field-dried high- and low-tannin sericea were investigated in a feeding trial with sheep (Ovis spp.). Field-drying had no effect on crude protein (CP) and fiber content of sericea, but shifted CT from extractable to bound forms. Digestion coefficients for CP, neutral detergent fiber (NDF), and acid detergent fiber (ADF) were lower for high-tannin sericea than the low-tannin type. Field-drying had no effect on fiber digestibility but increased CP digestibility and N retention in sheep fed high-tannin forage. Apparent digestion of CT was high for all treatments, but this is likely due to difficulty in analyzing CT in fecal material. Nutritional effects of CT in sericea lespedeza are related to both total CT and proportion of bound and unbound CT in the forage

    Genetic and Linguistic Coevolution in Northern Island Melanesia

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    Recent studies have detailed a remarkable degree of genetic and linguistic diversity in Northern Island Melanesia. Here we utilize that diversity to examine two models of genetic and linguistic coevolution. The first model predicts that genetic and linguistic correspondences formed following population splits and isolation at the time of early range expansions into the region. The second is analogous to the genetic model of isolation by distance, and it predicts that genetic and linguistic correspondences formed through continuing genetic and linguistic exchange between neighboring populations. We tested the predictions of the two models by comparing observed and simulated patterns of genetic variation, genetic and linguistic trees, and matrices of genetic, linguistic, and geographic distances. The data consist of 751 autosomal microsatellites and 108 structural linguistic features collected from 33 Northern Island Melanesian populations. The results of the tests indicate that linguistic and genetic exchange have erased any evidence of a splitting and isolation process that might have occurred early in the settlement history of the region. The correlation patterns are also inconsistent with the predictions of the isolation by distance coevolutionary process in the larger Northern Island Melanesian region, but there is strong evidence for the process in the rugged interior of the largest island in the region (New Britain). There we found some of the strongest recorded correlations between genetic, linguistic, and geographic distances. We also found that, throughout the region, linguistic features have generally been less likely to diffuse across population boundaries than genes. The results from our study, based on exceptionally fine-grained data, show that local genetic and linguistic exchange are likely to obscure evidence of the early history of a region, and that language barriers do not particularly hinder genetic exchange. In contrast, global patterns may emphasize more ancient demographic events, including population splits associated with the early colonization of major world regions

    Anthelmintic Effects of Sericea Lespedeza Hay Fed to Goats Infected With \u3cem\u3eHaemonchus Contortus\u3c/em\u3e

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    Infection with gastrointestinal nematodes (GIN), particularly Haemonchus contortus, is the major hindrance to economic goat production in the southern USA. Grazing forages high in condensed tannins (CT) or adding purified CT to the diet has been shown to reduce numbers of parasite eggs in sheep and goat faeces (Min & Hart, 2003). An alternative to grazing is feeding hay from CT-containing forages to livestock to reduce the effects of GIN (Shaik et al., 2004). The purpose of the current study was to test potential anthelmintic effects of feeding sericea lespedeza [(Lespedeza cuneata (Dum.-Cours.) G. Don] hay to goats

    Differential gene expression in response to fungal pathogen exposure in the aquatic invertebrate, 'Daphnia dentifera'

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    While vertebrate immune systems are appreciated for their complexity and adaptability, invertebrate immunity is often considered to be less complex. However, immune responses in many invertebrates likely involve sophisticated processes. Interactions between the crustacean host Daphnia dentifera and its fungal pathogen Metschnikowia bicuspidata provide an excellent model for exploring the mechanisms underlying crustacean immunity. To explore the genomic basis of immunity in Daphnia, we used RNA‐sequencing technology to quantify differential gene expression between individuals of a single host genotype exposed or unexposed to M. bicuspidata over 24 h. Transcriptomic analyses showed that the number of differentially expressed genes between the control (unexposed) and experimental (exposed) groups increased over time. Gene ontology enrichment analysis revealed that differentially expressed genes were enriched for immune‐related molecules and processes, such as cuticle development, prostaglandin, and defense response processes. Our findings provide a suite of immunologically relevant genes and suggest the presence of a rapidly upregulated immune response involving the cuticle in Daphnia. Studies involving gene expression responses to pathogen exposure shine a light on the processes occurring during the course of infection. By leveraging knowledge on the genetic basis for immunity, immune mechanisms can be more thoroughly understood to refine our understanding of disease spread within invertebrate populations.Published versio

    Researching the use of force: The background to the international project

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    This article provides the background to an international project on use of force by the police that was carried out in eight countries. Force is often considered to be the defining characteristic of policing and much research has been conducted on the determinants, prevalence and control of the use of force, particularly in the United States. However, little work has looked at police officers’ own views on the use of force, in particular the way in which they justify it. Using a hypothetical encounter developed for this project, researchers in each country conducted focus groups with police officers in which they were encouraged to talk about the use of force. The results show interesting similarities and differences across countries and demonstrate the value of using this kind of research focus and methodology
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