179 research outputs found
Efficient remittance services for development in the Pacific
Capital inflows to the Pacific islands from aid, foreign investment and remittances are an important source of development finance. Remittances are the fastest growing; they now total US 40 million per year. Hypotheses about the continued reliance on high transaction cost methods are examined and implications for development policy are discussed
Teff: A New Annual Forage Grass for South Dakota?
Teff (Eragrostis tef Zucc. Trotter) is a major cereal crop in Ethiopia and has been grown in other African countries as a hay crop. Teff is a warm-season, annual grass that has rapid seed germination and seedling development. It also is well adapted to dry climates. These qualities indicate that teff could be used in this region of the U.S. as a supplemental forage during periods when other forage supplies are diminished. In South Dakota, late summer is when forage supplies are typically low. Teff has been marketed recently in South Dakota under the name “Dessie Summer Lovegrass.” This marketing campaign has created interest among producers in the crop’s forage potential. The following information summarizes research conducted at SDSU, over several years, on the forage potential of teff
Cowpeas - A New Forage Crop for South Dakota
In the northern Great Plains, cool-season pastures decline in productivity during summer. This reduces available forage supplies. Solutions to forage shortages during the summer traditionally have included the use of perennial and annual warm-season species for pastures, hay, or silage. Cowpeas, a non-traditional crop suitable for summer forage, have been investigated recently at SDSU. Cowpeas (Vigna unguiculata [L.] Walp.) are an important legume in the southeastern United States, but since 1940 they have been replaced gradually by soybeans, clovers, and other legumes. Referred to as “black-eyed peas,” cowpeas are grown primarily for human consumption but also are suitable for hay, silage, and pasture
Symptoms, Distribution and Abundance of the Stem-Boring Caterpillar, Blastobasis repartella (Dietz), in Switchgrass
A potential pest of switchgrass, Panicum virgatum L., was first detected in South Dakota in 2004, where death of partially emerged leaves was noted in a small proportion of tillers. Similar “dead heart” symptoms were observed in switchgrass in Illinois during 2008 and adults of a stem-boring caterpillar were collected and identified as Blastobasis repartella (Dietz). In 2009, a survey of the central United States was used to estimate the distribution and abundance of this insect. In eight northern states, B. repartella was consistently found in both cultivated plots and natural stands of switchgrass. In four southern states, B. repartella was not detected. However, because symptoms are conspicuous for a short period of time, failure to collect stem-borers on one survey date for each southern location does not necessarily define the limit of distribution for B. repartella. Sampling in four northern states showed the proportion of tillers damaged by B. repartella ranged from 1.0–7.2%. Unlike some caterpillars that feed on native grasses, it appears that the egg-laying behavior of adult moths may preclude the use of prescribed burns as an effective method to suppress this stem-boring caterpillar. As a potential pest of switchgrass planted for biomass production, near-term research needs include refining the geographic distribution of B. repartella, quantifying potential losses of switchgrass biomass, and determining whether switchgrass may be bred for resistance this and other stem-boring insects
First cohomology groups for finite groups of Lie type in defining characteristic
Let G be a finite group of Lie type, defined over a field k of characteristic p > 0 . We find explicit bounds for the dimensions of the first cohomology groups for with coefficients in simple kG-modules. We proceed by bounding the number of composition factors of Weyl modules for simple algebraic groups independently of P and using this to deduce bounds for the 1-cohomology of simple algebraic groups. If γl denotes the (finite) maximum of the dimensions of the 1-cohomology groups over all Lie groups of rank l we find bounds for the growth rate of the sequence. {γl}We show that log γl is O(l3log l
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EcoHIV infection of mice establishes latent viral reservoirs in T cells and active viral reservoirs in macrophages that are sufficient for induction of neurocognitive impairment
Suppression of HIV replication by antiretroviral therapy (ART) or host immunity can prevent AIDS but not other HIV-associated conditions including neurocognitive impairment (HIV-NCI). Pathogenesis in HIV-suppressed individuals has been attributed to reservoirs of latent-inducible virus in resting CD4+ T cells. Macrophages are persistently infected with HIV but their role as HIV reservoirs in vivo has not been fully explored. Here we show that infection of conventional mice with chimeric HIV, EcoHIV, reproduces physiological conditions for development of disease in people on ART including immunocompetence, stable suppression of HIV replication, persistence of integrated, replication-competent HIV in T cells and macrophages, and manifestation of learning and memory deficits in behavioral tests, termed here murine HIV-NCI. EcoHIV established latent reservoirs in CD4+ T lymphocytes in chronically-infected mice but could be induced by epigenetic modulators ex vivo and in mice. In contrast, macrophages expressed EcoHIV constitutively in mice for up to 16 months; murine leukemia virus (MLV), the donor of gp80 envelope in EcoHIV, did not infect macrophages. Both EcoHIV and MLV were found in brain tissue of infected mice but only EcoHIV induced NCI. Murine HIV-NCI was prevented by antiretroviral prophylaxis but once established neither persistent EcoHIV infection in mice nor NCI could be reversed by long-acting antiretroviral therapy. EcoHIV-infected, athymic mice were more permissive to virus replication in macrophages than were wild-type mice, suffered cognitive dysfunction, as well as increased numbers of monocytes and macrophages infiltrating the brain. Our results suggest an important role of HIV expressing macrophages in HIV neuropathogenesis in hosts with suppressed HIV replication
The genetic basis for panicle trait variation in switchgrass (Panicum virgatum)
Key message: We investigate the genetic basis of panicle architecture in switchgrass in two mapping populations across a latitudinal gradient, and find many stable, repeatable genetic effects and limited genetic interactions with the environment. Abstract: Grass species exhibit large diversity in panicle architecture influenced by genes, the environment, and their interaction. The genetic study of panicle architecture in perennial grasses is limited. In this study, we evaluate the genetic basis of panicle architecture including panicle length, primary branching number, and secondary branching number in an outcrossed switchgrass QTL population grown across ten field sites in the central USA through multi-environment mixed QTL analysis. We also evaluate genetic effects in a diversity panel of switchgrass grown at three of the ten field sites using genome-wide association (GWAS) and multivariate adaptive shrinkage. Furthermore, we search for candidate genes underlying panicle traits in both of these independent mapping populations. Overall, 18 QTL were detected in the QTL mapping population for the three panicle traits, and 146 unlinked genomic regions in the diversity panel affected one or more panicle trait. Twelve of the QTL exhibited consistent effects (i.e., no QTL by environment interactions or no QTL × E), and most (four of six) of the effects with QTL × E exhibited site-specific effects. Most (59.3%) significant partially linked diversity panel SNPs had significant effects in all panicle traits and all field sites and showed pervasive pleiotropy and limited environment interactions. Panicle QTL co-localized with significant SNPs found using GWAS, providing additional power to distinguish between true and false associations in the diversity panel
Assessing the cost of global biodiversity and conservation knowledge
Knowledge products comprise assessments of authoritative information supported by stan-dards, governance, quality control, data, tools, and capacity building mechanisms. Considerable resources are dedicated to developing and maintaining knowledge productsfor biodiversity conservation, and they are widely used to inform policy and advise decisionmakers and practitioners. However, the financial cost of delivering this information is largelyundocumented. We evaluated the costs and funding sources for developing and maintain-ing four global biodiversity and conservation knowledge products: The IUCN Red List ofThreatened Species, the IUCN Red List of Ecosystems, Protected Planet, and the WorldDatabase of Key Biodiversity Areas. These are secondary data sets, built on primary datacollected by extensive networks of expert contributors worldwide. We estimate that US116–204 million), plus 293 person-years of volunteer time (range: 278–308 person-years) valued at US12–16 million), were invested inthese four knowledge products between 1979 and 2013. More than half of this financingwas provided through philanthropy, and nearly three-quarters was spent on personnelcosts. The estimated annual cost of maintaining data and platforms for three of these knowl-edge products (excluding the IUCN Red List of Ecosystems for which annual costs were notpossible to estimate for 2013) is US6.2–6.7 million). We esti-mated that an additional US12 million. These costs are much lower than those tomaintain many other, similarly important, global knowledge products. Ensuring that biodi-versity and conservation knowledge products are sufficiently up to date, comprehensiveand accurate is fundamental to inform decision-making for biodiversity conservation andsustainable development. Thus, the development and implementation of plans for sustain-able long-term financing for them is critical
The short-term mortality fluctuation data series, monitoring mortality shocks across time and space.
The COVID-19 pandemic has revealed substantial coverage and quality gaps in existing international and national statistical monitoring systems. It is striking that obtaining timely, accurate, and comparable across countries data in order to adequately respond to unexpected epidemiological threats is very challenging. The most robust and reliable approach to quantify the mortality burden due to short-term risk factors is based on estimating weekly excess deaths. This approach is more reliable than monitoring deaths with COVID-19 diagnosis or calculating incidence or fatality rates affected by numerous problems such as testing coverage and comparability of diagnostic approaches. In response to the emerging data challenges, a new data resource on weekly mortality has been established. The Short-term Mortality Fluctuations (STMF, available at www.mortality.org ) data series is the first international database providing open-access harmonized, uniform, and fully documented data on weekly all-cause mortality. The STMF online vizualisation tool provides an opportunity to perform a quick assessment of the excess weekly mortality in one or several countries by means of an interactive graphical interface
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