68 research outputs found
Nitrogen and Fiber Digestion in Sheep Fed Fresh-Frozen and Field-Dried High and Low Tannin Sericea Lespedeza
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
Anthelmintic Effects of Sericea Lespedeza Hay Fed to Goats Infected With \u3cem\u3eHaemonchus Contortus\u3c/em\u3e
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
Early infant HIV-1 diagnosis programs in resource-limited settings: opportunities for improved outcomes and more cost-effective interventions
Early infant diagnosis (EID) of HIV-1 infection confers substantial benefits to HIV-infected and HIV-uninfected infants, to their families, and to programs providing prevention of mother-to-child transmission (PMTCT) services, but has been challenging to implement in resource-limited settings. In order to correctly inform parents/caregivers of infant infection status and link HIV-infected infants to care and treatment, a 'cascade' of events must successfully occur. A frequently cited barrier to expansion of EID programs is the cost of the required laboratory assays. However, substantial implementation barriers, as well as personnel and infrastructure requirements, exist at each step in the cascade. In this update, we review challenges to uptake at each step in the EID cascade, highlighting that even with the highest reported levels of uptake, nearly half of HIV-infected infants may not complete the cascade successfully. We next synthesize the available literature about the costs and cost effectiveness of EID programs; identify areas for future research; and place these findings within the context of the benefits and challenges to EID implementation in resource-limited settings
The AgMIP Coordinated Climate-Crop Modeling Project (C3MP): Methods and Protocols
Climate change is expected to alter a multitude of factors important to agricultural
systems, including pests, diseases, weeds, extreme climate events, water resources,
soil degradation, and socio-economic pressures. Changes to carbon dioxide concentration
([CO2]), temperature, andwater (CTW) will be the primary drivers of change
in crop growth and agricultural systems. Therefore, establishing the CTW-change
sensitivity of crop yields is an urgent research need and warrants diverse methods
of investigation. Crop models provide a biophysical, process-based tool to investigate crop
responses across varying environmental conditions and farm management techniques,
and have been applied in climate impact assessment by using a variety of
methods (White et al., 2011, and references therein). However, there is a significant
amount of divergence between various crop models’ responses to CTW changes
(R¨otter et al., 2011). While the application of a site-based crop model is relatively
simple, the coordination of such agricultural impact assessments on larger scales
requires consistent and timely contributions from a large number of crop modelers,
each time a new global climate model (GCM) scenario or downscaling technique
is created. A coordinated, global effort to rapidly examine CTW sensitivity across
multiple crops, crop models, and sites is needed to aid model development and
enhance the assessment of climate impacts (Deser et al., 2012)..
Quantitative estimates of glacial refugia for chimpanzees ( Pan troglodytes ) since the Last Interglacial (120,000 BP)
Paleoclimate reconstructions have enhanced our understanding of how past climates have shaped present-day biodiversity. We hypothesize that the geographic extent of Pleistocene forest refugia and suitable habitat fluctuated significantly in time during the late Quaternary for chimpanzees (Pan troglodytes). Using bioclimatic variables representing monthly temperature and precipitation estimates, past human population density data, and an extensive database of georeferenced presence points, we built a model of changing habitat suitability for chimpanzees at fine spatio-temporal scales dating back to the Last Interglacial (120,000 BP). Our models cover a spatial resolution of 0.0467° (approximately 5.19 km2 grid cells) and a temporal resolution of between 1000 and 4000 years. Using our model, we mapped habitat stability over time using three approaches, comparing our modeled stability estimates to existing knowledge of Afrotropical refugia, as well as contemporary patterns of major keystone tropical food resources used by chimpanzees, figs (Moraceae), and palms (Arecacae). Results show habitat stability congruent with known glacial refugia across Africa, suggesting their extents may have been underestimated for chimpanzees, with potentially up to approximately 60,000 km2 of previously unrecognized glacial refugia. The refugia we highlight coincide with higher species richness for figs and palms. Our results provide spatio-temporally explicit insights into the role of refugia across the chimpanzee range, forming the empirical foundation for developing and testing hypotheses about behavioral, ecological, and genetic diversity with additional data. This methodology can be applied to other species and geographic areas when sufficient data are available
Accuracy Assessment of the ESA CCI 20M Land Cover Map: Kenya, Gabon, Ivory Coast and South Africa
This working paper presents the overall and spatial accuracy assessment of the European Space Agency (ESA) 20 m prototype land cover map for Africa for four countries: Kenya, Gabon, Ivory Coast and South Africa. This accuracy assessment was undertaken as part of the ESA-funded CrowdVal project. The results varied from 44% (for South Africa) to 91% (for Gabon). In the case of Kenya (56% overall accuracy) and South Africa, these values are largely caused by the confusion between grassland and shrubland. However, if a weighted confusion matrix is used, which diminishes the importance of the confusion between grassland and shrubs, the overall accuracy for Kenya increases to 79% and for South Africa, 75%. The overall accuracy for Ivory Coast (47%) is a result of a highly fragmented land cover, which makes it a difficult country to map with remote sensing. The exception was Gabon with a high overall accuracy of 91%, but this can be explained by the high amount of tree cover across the country, which is a relatively easy class to map
Socializing One Health: an innovative strategy to investigate social and behavioral risks of emerging viral threats
In an effort to strengthen global capacity to prevent, detect, and control infectious diseases in animals and people, the United States Agency for International Development’s (USAID) Emerging Pandemic Threats (EPT) PREDICT project funded development of regional, national, and local One Health capacities for early disease detection, rapid response, disease control, and risk reduction. From the outset, the EPT approach was inclusive of social science research methods designed to understand the contexts and behaviors of communities living and working at human-animal-environment interfaces considered high-risk for virus emergence. Using qualitative and quantitative approaches, PREDICT behavioral research aimed to identify and assess a range of socio-cultural behaviors that could be influential in zoonotic disease emergence, amplification, and transmission. This broad approach to behavioral risk characterization enabled us to identify and characterize human activities that could be linked to the transmission dynamics of new and emerging viruses. This paper provides a discussion of implementation of a social science approach within a zoonotic surveillance framework. We conducted in-depth ethnographic interviews and focus groups to better understand the individual- and community-level knowledge, attitudes, and practices that potentially put participants at risk for zoonotic disease transmission from the animals they live and work with, across 6 interface domains. When we asked highly-exposed individuals (ie. bushmeat hunters, wildlife or guano farmers) about the risk they perceived in their occupational activities, most did not perceive it to be risky, whether because it was normalized by years (or generations) of doing such an activity, or due to lack of information about potential risks. Integrating the social sciences allows investigations of the specific human activities that are hypothesized to drive disease emergence, amplification, and transmission, in order to better substantiate behavioral disease drivers, along with the social dimensions of infection and transmission dynamics. Understanding these dynamics is critical to achieving health security--the protection from threats to health-- which requires investments in both collective and individual health security. Involving behavioral sciences into zoonotic disease surveillance allowed us to push toward fuller community integration and engagement and toward dialogue and implementation of recommendations for disease prevention and improved health security
Rapid Seedlings Regeneration From Seeds And Vegetative Propagation With Sucker And Rhizome Of Eremospatha Macrocarpa (Mann & Wendl.) Wendl And Laccosperma Secundiflorum (P. Beauv.) Kuntze
Direct regeneration of rattan seedlings from apical meristem and axillary bud explants
peer reviewe
Effects of feeding sericea lespedeza hay to goats infected with Haemonchus contortus
Infection with gastrointestinal nematodes (GIN) is a primary constraint to economic goat production in the southern USA. Anthelmintic resistance is highly prevalent in goat nematodes in this region, and non-chemical control methods are needed. Grazing of forages containing condensed tannins (CT) or feeding purified CT as part of the diet has shown potential for reducing parasite egg counts in faeces of sheep and goats, but little information is available on feeding hay from CT-containing forages. The anthelmintic potential of sericea lespedeza [Lespedeza cuneata (Dum-Cours.) G. Don] hay was evaluated in an 8-week feeding trial with goats. Twenty yearling Spanish-cross does were given a single challenge of 10,000 Haemonchus contortus infective (L3) larvae to boost their naturally acquired parasite load. After three weeks grazing, the does were moved to pens (5 animals per pen) and fed either ground sericea or bermudagrass [Cynodon dactylon (L.) Pers.] hay diets (treatment n = 10) balanced for crude protein and energy with a small amount of supplement. All 20 does were fed the bermudagrass diet for a 1-week adjustment period, after which two pens of animals were switched to the sericea diet for four weeks (trial period). All the does were then fed the bermudagrass diet for an additional three weeks. Throughout the experiment worm egg counts (FEC; faecal egg count) were done weekly for each doe. Egg shedding was similar between the two groups prior to feeding the treatment diets, significantly lower in sericea-fed goats during the 4-week trial period, and again similar during the 3-week post-trial period. Feeding sericea lespedeza hay to goats reduced nematode egg shedding and may have potential to reduce pasture contamination from GIN larvae. © South African Society for Animal Science
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