Nitrate concentrations recorded in Greenland ice rose by a factor of 2-3, particularly between the 1950s
and 1980s, reflecting a major change in NOx emissions reaching the background atmosphere. Increases in ice cores drilled at lower latitudes can be used to validate or constrain regional emission inventories. Background ammonium concentrations in Greenland ice show no significant recent trend, although the record is very noisy, being dominated by spikes of input from biomass burning events. Neither nitrate nor ammonium shows significant recent trends in Antarctica, although their natural variations are of biogeochemical Fedratinib ic50 and atmospheric chemical interest. Finally, it has been found that photolysis of nitrate in the snowpack leads to significant re-emissions of NOx that can strongly impact the regional atmosphere in snow-covered GSK J4 ic50 areas.”
“The BK virus is a double-stranded DNA virus to which 90% of adults have been exposed. BK virus infections typically result in an oral or respiratory
infection; however, BK virus reactivation is an infectious disease of concern in kidney transplant recipients. The prevalence of BK virus nephropathy (BKN) in kidney transplant recipients is approximately 5%, and most cases occur within one yr after kidney transplantation. Graft survival of BKN is reported to be 3060%, and the standard treatment strategy for BKN is reducing immunosuppressive therapy and close monitoring for rejection. Viral infection is most common in the early post-transplantation phase, and BKN or acute rejection is one of the major factors involved in graft loss. However, in this report, we describe the successful management of BKN and cytomegalovirus infection concurrent with plasma cellrich acute rejection.”
“Most population dynamics models explicitly track the density of a single sex. When the operational
sex ratio can vary, two-sex models may be needed to understand and predict population trajectories. Various functions have been proposed to describe the relative contributions of females and males to recruitment, and these functions can differ qualitatively in the patterns that they generate. Which mating function best describes the dynamics of real populations is PHA-848125 order not known, since alternative two-sex models have not been confronted with experimental data. We conducted the first such comparison, using laboratory populations of the bean beetle Callosobruchus maculatus. Manipulations of the operational sex ratio and total density provided strong support for a demographic model in which the birth rate was proportional to the harmonic mean of female and male densities, and females, males, and their offspring made unique contributions to density dependence. We offer guidelines for transferring this approach to other, less tractable systems in which possibilities for sex ratio manipulations are more limited.