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Likely Increase (likely + increase)
Selected AbstractsThe impact of storm events on solute exports from a glaciated forested watershed in western New York, USAHYDROLOGICAL PROCESSES, Issue 16 2006S. P. Inamdar Abstract This study analysed the importance of precipitation events from May 2003 to April 2004 on surface water chemistry and solute export from a 696 ha glaciated forested watershed in western New York State, USA. The specific objectives of the study were to determine: (a) the temporal patterns of solutes within individual storm events; (b) the impact of precipitation events on seasonal and annual export budgets; and (c) how solute concentrations and loads varied for precipitation events among seasons as functions of storm intensity and antecedent moisture conditions. Analysis of solute trajectories showed that NH4+, total Al and dissolved organic nitrogen (DON) peaked on the hydrograph rising limb, whereas dissolved organic carbon (DOC) concentrations peaked following the discharge peak. Sulphate and base-cations displayed a dilution pattern with a minimum around peak discharge. End-member mixing analysis showed that throughfall contributions were highest on the rising limb, whereas valley-bottom riparian waters peaked following the discharge peak. The trajectories of NO3, concentrations varied with season, indicating the influence of biotic processes on the generation, and hence flux, of this solute. Storm events had the greatest impact on the annual budgets for NH4+, K+, total dissolved Al, DON and DOC. Storm events during summer had the greatest impact on seasonal solute budgets. Summer events had the highest hourly discharges and high concentrations of solutes. However, NO3, and DOC exports during a spring snowmelt event were considerably more than those observed for large events during other periods of the year. Comparisons among storms showed that season, precipitation amount, and antecedent moisture conditions affected solute concentrations and loads. Concentrations of solutes were elevated for storms that occurred after dry antecedent conditions. Seven of the largest storms accounted for only 15% of the annual discharge, but were responsible for 34%, 19%, 64%, 13%, 39% and 24% of the annual exports of NH4+, K+, Al, NO3,, DON and DOC respectively. These results suggest that the intense and infrequent storms predicted for future climate-change scenarios will likely increase the exports of solutes like DOC, DON, NH4+, Al and K+ from watersheds. Copyright © 2006 John Wiley & Sons, Ltd. [source] Genetic estimates of contemporary effective population size: what can they tell us about the importance of genetic stochasticity for wild population persistence?MOLECULAR ECOLOGY, Issue 15 2008FRISO P. PALSTRA Abstract Genetic stochasticity due to small population size contributes to population extinction, especially when population fragmentation disrupts gene flow. Estimates of effective population size (Ne) can therefore be informative about population persistence, but there is a need for an assessment of their consistency and informative relevance. Here we review the body of empirical estimates of Ne for wild populations obtained with the temporal genetic method and published since Frankham's (1995) review. Theoretical considerations have identified important sources of bias for this analytical approach, and we use empirical data to investigate the extent of these biases. We find that particularly model selection and sampling require more attention in future studies. We report a median unbiased Ne estimate of 260 (among 83 studies) and find that this median estimate tends to be smaller for populations of conservation concern, which may therefore be more sensitive to genetic stochasticity. Furthermore, we report a median Ne/N ratio of 0.14, and find that this ratio may actually be higher for small populations, suggesting changes in biological interactions at low population abundances. We confirm the role of gene flow in countering genetic stochasticity by finding that Ne correlates strongest with neutral genetic metrics when populations can be considered isolated. This underlines the importance of gene flow for the estimation of Ne, and of population connectivity for conservation in general. Reductions in contemporary gene flow due to ongoing habitat fragmentation will likely increase the prevalence of genetic stochasticity, which should therefore remain a focal point in the conservation of biodiversity. [source] Speciation with gene flow could be commonMOLECULAR ECOLOGY, Issue 9 2008PATRIK NOSIL Abstract The likelihood of speciation in the face of homogenizing gene flow (i.e. without complete geographical isolation) is one of the most debated topics in evolutionary biology. Demonstrating this phenonemon is hampered by the difficulty of isolating the effects of time since population divergence vs. gene flow on levels of molecular genetic differentiation. For example, weak genetic differentiation between taxa could be due to recent divergence, gene flow, or a combination of these factors. Nonetheless, a number of convincing examples of speciation with gene flow have recently emerged, owing in part to the development of new analytical methods designed to estimate gene flow specifically. A recent example of speciation with gene flow in salamanders (Niemiller et al. 2008) further advances our understanding of this phenonemon, by showing that gene flow between cave and spring salamanders was ongoing during speciation, rather than having occurred after a long period of allopatric divergence. Future work on the ecological and genetic factors reducing gene flow will likely increase our understanding of the conditions that faciliate divergence in the face of gene flow. [source] Movement disorders and pregnancy: A review of the literature,,MOVEMENT DISORDERS, Issue 6 2010Sarah M. Kranick MD Abstract Pregnant patients are rarely encountered in the movement disorders clinic, but they present significant dilemmas regarding treatment and counseling for neurologists. While movement disorders in pregnancy once described those disorders arising de novo during pregnancy, such as chorea gravidarum or restless leg syndrome, advancing maternal age in Western countries will likely increase the number of women in whom pregnancy complicates a pre-existing movement disorder. Physicians treating these women must be aware of the impact of the movement disorder and its treatment on fertility, pregnancy, fetal development, lactation, and infant care. This review summarizes retrospective series and case reports to both guide clinicians and to stimulate and direct the design of prospective studies. © 2010 Movement Disorder Society [source] The Socioeconomic Impact of Atopic Dermatitis in the United States: A Systematic ReviewPEDIATRIC DERMATOLOGY, Issue 1 2008Anthony J. Mancini M.D. A search was performed using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the International Agency for Health Technology Assessment (INAHTA) database, and the Cochrane Library. All abstracts were reviewed for the following criteria: original cost data, studies performed in the United States, and English language. The search yielded 418 papers. Fifty-nine papers were reviewed in detail, and four studies were found that met the inclusion criteria. These cost-identification analyses estimated the cost of atopic dermatitis heterogeneously and could not be compared directly. National cost estimates ranged widely, from $364 million to $3.8 billion US dollars per year. The cost of atopic dermatitis is significant and will likely increase in proportion to increasing disease prevalence. Measurement of the cost of atopic dermatitis in the United States has been limited to direct cost-identification analyses, with few studies measuring the indirect cost of disease. [source] Pivotal studies of orphan drugs approved for neurological diseases,ANNALS OF NEUROLOGY, Issue 2 2009Jun Mitsumoto MPH Objective To identify design elements of clinical trials leading to US Food and Drug Administration approval of drugs for neurological diseases with and without orphan indications. Methods We used publicly available information to identify approvals for drugs for neurological diseases with an orphan indication (n = 19) and compared them with recent approvals for drugs for neurological diseases without an orphan indication (n = 20). We identified "pivotal trials" from drug labels and drug approval packages, and assessed them on four elements of clinical trial design: control, blinding, randomization, and size. Results All drugs for neurological diseases (100%) approved without an orphan indication included at least two randomized, double-blind, placebo-controlled trials. In comparison, 32% of drugs with an orphan indication had at least two such trials (p < 0.001) and 74% had at least one (p = 0.02). Thirty-three pivotal trials were conducted for the 19 drugs approved with an orphan indication. Of the 33 trials, 11 (33%) did not use a placebo control, 9 (27%) were not double blind, and 4 (12%) were not randomized. Drugs approved without an orphan indication had more pivotal trials per drug (3.8 vs 1.7 trials; p < 0.001) and a larger mean trial size (506 vs 164 trial participants; p < 0.001). Interpretation The US Food and Drug Administration has approved orphan drugs for neurological diseases without randomized, doubled-blind, placebo-controlled pivotal trials. As orphan drug development grows, demand will likely increase for alternative designs for conducting adequate and well-controlled studies to demonstrate drug efficacy. Ann Neurol 2009;66:184,190 [source] Climate Change and Emergency Medicine: Impacts and OpportunitiesACADEMIC EMERGENCY MEDICINE, Issue 8 2009Jeremy J. Hess MD Abstract There is scientific consensus that the climate is changing, that human activity plays a major role, and that the changes will continue through this century. Expert consensus holds that significant health effects are very likely. Public health and health care systems must understand these impacts to properly pursue preparedness and prevention activities. All of medicine will very likely be affected, and certain medical specialties are likely to be more significantly burdened based on their clinical activity, ease of public access, public health roles, and energy use profiles. These specialties have been called on to consider the likely impacts on their patients and practice and to prepare their practitioners. Emergency medicine (EM), with its focus on urgent and emergent ambulatory care, role as a safety-net provider, urban concentration, and broad-based clinical mission, will very likely experience a significant rise in demand for its services over and above current annual increases. Clinically, EM will see amplification of weather-related disease patterns and shifts in disease distribution. In EM's prehospital care and disaster response activities, both emergency medical services (EMS) activity and disaster medical assistance team (DMAT) deployment activities will likely increase. EM's public health roles, including disaster preparedness, emergency department (ED)-based surveillance, and safety-net care, are likely to face increasing demands, along with pressures to improve fuel efficiency and reduce greenhouse gas emissions. Finally, EM's roles in ED and hospital management, particularly related to building and purchasing, are likely to be impacted by efforts to reduce greenhouse gas emissions and enhance energy efficiency. Climate change thus presents multiple clinical and public health challenges to EM, but also creates numerous opportunities for research, education, and leadership on an emerging health issue of global scope. [source] | ||||||||||