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81.
Susan Morrison Grace John-Stewart John J. Egessa Sezi Mubezi Sylvia Kusemererwa Dennis K. Bii Nulu Bulya Francis Mugume James D. Campbell Jonathan Wangisi Elizabeth A. Bukusi Connie Celum Jared M. Baeten Partners PrEP Study Team 《PloS one》2015,10(10)
During an HIV-1 prevention clinical trial in East Africa, we observed 16 cases of primary HIV-1 infection in women coincident with pregnancy or breastfeeding. Nine of eleven pregnant women initiated rapid combination antiretroviral therapy (ART), despite having CD4 counts exceeding national criteria for ART initiation; breastfeeding women initiated ART or replacement feeding. Rapid ART initiation during primary HIV-1 infection during pregnancy and breastfeeding is feasible in this setting. 相似文献
82.
The microbial metabolism of organic matter (OM) in seagrass beds can create sulfidic conditions detrimental to seagrass growth;
iron (Fe) potentially has ameliorating effects through titration of the sulfides and the precipitation of iron-sulfide minerals
into the sediment. In this study, the biogeochemical effects of Fe availability and its interplay with sulfur and OM on sulfide
toxicity, phosphorous (P) availability, seagrass growth and community structure were tested. The availability of Fe and OM
was manipulated in a 2 × 2 factorial experiment arranged in a Latin square, with four replicates per treatment. The treatments
included the addition of Fe, the addition of OM, the addition of both Fe and OM as well as no addition. The experiment was
conducted in an oligotrophic, iron-deficient seagrass bed. Fe had an 84.5% retention efficiency in the sediments with the
concentration of Fe increasing in the seagrass leaves over the course of the experiment. Porewater chemistry was significantly
altered with a dramatic decrease in sulfide levels in Fe addition plots while sulfide levels increased in the OM addition
treatments. Phosphorus increased in seagrass leaves collected in the Fe addition plots. Decreased sulfide stress was evidenced
by heavier δ34S in leaves and rhizomes from plots to which Fe was added. The OM addition negatively affected seagrass growth but increased
P availability; the reduced sulfide stress in Fe added plots resulted in elevated productivity. Fe availability may be an
important determinant of the impact that OM has on seagrass vitality in carbonate sediments vegetated with seagrasses. 相似文献
83.
Using a combination of a primary growth retardant, mefluidide, a synergistic additive, chlorsulfuron, a detergent to enhance penetration (X-77), and a herbicide, 2,4-D, to provide for control of broadleaf weeds, full-season management of bluegrass (Poa pratensis L.)—tall fescue (Festuca arundinaceae Schreb.) mixtures along roadsides has been achieved. A single spray application is made in the spring, and no additional herbicide applications or mechanical mowing are needed. The treatment is effective with greater than 90% control of fescue seed heads. Those few seed heads that do form remain short. It is economical. The costs of materials and application are equal to or less than the cost of a single mowing cycle. The treatment is environmentally safe when applied in early spring before most agricultural crops have been planted. The effectiveness and low cost of the combination derive from laboratory and greenhouse observations that various materials, herein referred to as additives, often only weakly effective as growth retardants themselves, will interact synergistically with mefluidide to provide overall treatment effectiveness at application rates that are economical. Using this principle, a combination suitable for roadside vegetation management was devised, field-tested for 2 years under actual use conditions, and found to be effective for full-season vegetation management of mixed bluegrass—tall fescue turf to permit considerable cost savings when compared to three-cycle mechanical mowing. 相似文献
84.
Direct evidence is presented for a proline cycle using a cell-free experimental system which sequentially transfers 3H from [1-3H]glucose to NADP+ to Δ1-pyrroline-5-carboxylate and yields [3H]proline. The formation of [3H]proline depends on the presence of NADP, Δ1-pyrroline-5-carboxylate, and the enzymes glucose-6-phosphate dehydrogenase and Δ1-pyrroline-5-carboxylate reductase. The production of [3H]proline from unlabeled proline in the presence of mitochondria provides direct evidence for one complete turn of a proline cycle which transfers reducing equivalents produced by glucose oxidation in the pentose pathway into mitochondria. In this cycle, proline is oxidized to Δ1-pyrroline-5-carboxylate by mitochondrial proline oxidase. Δ1-pyrroline-5-carboxylate is released from mitochondria and is recycled back to proline by Δ1-pyrroline-5-carboxylate reductase with concomitant oxidation of NADPH. At the maximal rate observed, 60% of Δ1-pyrroline-5-carboxylate produced is recycled back to proline. This cycle provides a mechanism for transferring reducing equivalents from NADPH into mitochondria and is linked to glucose oxidation in the pentose pathway by NADPH turnover. 相似文献
85.
Sport hunting has reportedly multiple benefits to economies and local communities; however, few of these benefits have been quantified. As part of their lease agreements with the Zambia Wildlife Authority, sport hunting operators in Zambia are required to provide annually to local communities free of charge i.e., provision a percentage of the meat obtained through sport hunting. We characterized provisioning of game meat to rural communities by the sport hunting industry in Zambia for three game management areas (GMAs) during 2004–2011. Rural communities located within GMAs where sport hunting occurred received on average > 6,000 kgs per GMA of fresh game meat annually from hunting operators. To assess hunting industry compliance, we also compared the amount of meat expected as per the lease agreements versus observed amounts of meat provisioned from three GMAs during 2007–2009. In seven of eight annual comparisons of these GMAs, provisioning of meat exceeded what was required in the lease agreements. Provisioning occurred throughout the hunting season and peaked during the end of the dry season (September–October) coincident with when rural Zambians are most likely to encounter food shortages. We extrapolated our results across all GMAs and estimated 129,771 kgs of fresh game meat provisioned annually by the sport hunting industry to rural communities in Zambia at an approximate value for the meat alone of >US$600,000 exclusive of distribution costs. During the hunting moratorium (2013–2014), this supply of meat has halted, likely adversely affecting rural communities previously reliant on this food source. Proposed alternatives to sport hunting should consider protein provisioning in addition to other benefits (e.g., employment, community pledges, anti-poaching funds) that rural Zambian communities receive from the sport hunting industry. 相似文献
86.
The active moieties of the anti-biofilm natural compounds zosteric (ZA) and salicylic (SA) acids have been covalently immobilized on a low density polyethylene (LDPE) surface. The grafting procedure provided new non-toxic eco-friendly materials (LDPE-CA and LDPE-SA) with anti-biofilm properties superior to the conventional biocide-based approaches and with features suitable for applications in challenging fields where the use of antimicrobial agents is limited. Microbiological investigation proved that LDPE-CA and LDPE-SA: (1) reduced Escherichia coli biofilm biomass by up to 61% with a mechanism that did not affect bacterial viability; (2) significantly affected biofilm morphology, decreasing biofilm thickness, roughness, substratum coverage, cell and matrix polysaccharide bio-volumes by >80% and increasing the surface to bio-volume ratio; (3) made the biofilm more susceptible to ampicillin and ethanol. Since no molecules were leached from the surface, they remained constantly effective and below the lethal level; therefore, the risk of inducing resistance was minimized. 相似文献
87.
The heart is one of the least regenerative organs in the body, and highly vulnerable to the increasing incidence of cardiovascular diseases in an aging world population. Cell-based approaches aimed at cardiac repair have recently caused great public excitement. But clinical trials of patients’ own skeletal myoblasts or bone marrow cells for transplantation have been disappointing. Human embryonic stem cells (hESCs) form bona fide cardiomyocytes in vitro which are readily generated in mass culture and are being tested in animal models of heart damage. The early results, while encouraging, underscore that much remains to be done. This review focuses on the many challenges that remain before hESCs-mediated repair of the human heart becomes a reality. 相似文献
88.
Jill S. Marty James P. Higham Elizabeth L. Gadsby Caroline Ross 《International journal of primatology》2009,30(6):807-823
Sexual selection has driven the evolution and elaboration of a wide variety of displays and ornaments in male nonhuman primates,
including capes, cheek flanges, and sexual coloration. Among the most sexually dimorphic of all primates is the drill (Mandrillus leucophaeus), the males of which can be 3 times the mass of females, possess large canines, and exhibit extremely bright sexual skin
coloration. However, the function of male coloration in this species has never been examined. Here, we present data on male
color (measured objectively using digital photography), dominance rank, measures of male-female association, and key sexual
behaviors, of adult male drills (n = 17) living in four semi free-ranging enclosures at the Drill Rehabilitation and Breeding Center in Nigeria. We test the
hypothesis that male coloration is a badge of status, indicating dominance rank, and the hypothesis that male coloration attracts
females. We found that male coloration did indicate rank, and that high ranking, strongly colored males were more likely to
associate with adult females, and more specifically with fully tumescent females. These males also engaged in more sexual
activity. However, measures of male-female association and sexual behaviors were not related to male color once rank had been
taken into consideration; i.e., for males of a given rank, females did not prefer those that were more colorful. We discuss
the results in light of what is known about the wild drill social system, in which unfamiliar individuals may come together
in “supergroups,” and in which quality indicators of competitive ability may be particularly important. 相似文献
89.
Expanded thermal niche for a diving vertebrate: A leatherback turtle diving into near-freezing water
Michael C. James Graeme C. Hays 《Journal of experimental marine biology and ecology》2006,335(2):221-226
The global distribution of extant reptiles is more limited than that of mammals or birds, with low reptilian species diversity at high latitudes. Central to this limited geographical distribution is the ectothermic nature of reptiles, which means that they generally become torpid at cold temperatures. However, here we report the first detailed telemetry from a leatherback turtle (Dermochelys coriacea) diving in cold water at high latitude. An individual equipped with a satellite tag that relayed temperature-depth profiles dived continuously for many weeks into sub-surface waters as cold as 0.4 °C. Global warming will likely increase the foraging range of leatherback turtles further into temperate and boreal waters. 相似文献
90.