Fine sediment reduces vertical migrations of Gammarus pulex (Crustacea: Amphipoda) in response to surface water loss

Surface and subsurface sediments in river ecosystems are recognized as refuges that may promote invertebrate survival during disturbances such as floods and streambed drying. Refuge use is spatiotemporally variable, with environmental factors including substrate composition, in particular the proportion of fine sediment (FS), affecting the ability of organisms to move through interstitial spaces. We conducted a laboratory experiment to examine the effects of FS on the movement of Gammarus pulex Linnaeus (Crustacea: Amphipoda) into subsurface sediments in response to surface water loss. We hypothesized that increasing volumes of FS would impede and ultimately prevent individuals from migrating into the sediments. To test this hypothesis, the proportion of FS (1–2 mm diameter) present within an open gravel matrix (4–16 mm diameter) was varied from 10 to 20% by volume in 2.5% increments. Under control conditions (0% FS), 93% of individuals moved into subsurface sediments as the water level was reduced. The proportion of individuals moving into the subsurface decreased to 74% at 10% FS, and at 20% FS no individuals entered the sediments, supporting our hypothesis. These results demonstrate the importance of reducing FS inputs into river ecosystems and restoring FS-clogged riverbeds, to promote refuge use during increasingly common instream disturbances

Does HAART Efficacy Translate to Effectiveness? Evidence for a Trial Effect

Background: Patients who participate in clinical trials may experience better clinical outcomes than patients who initiate similar therapy within clinical care (trial effect), but no published studies have evaluated a trial effect in HIV clinical trials. Methods: To examine a trial effect we compared virologic suppression (VS) among patients who initiated HAART in a clinical trial versus in routine clinical care. VS was defined as a plasma HIV RNA #400 copies/ml at six months after HAART initiation and was assessed within strata of early (1996–99) or current (2000–06) HAART periods. Risk ratios (RR) were estimated using binomial models. Results: Of 738 persons initiating HAART, 30.6 % were women, 61.7 % were black, 30 % initiated therapy in a clinical trial and 67 % (n = 496) had an evaluable six month HIV RNA result. HAART regimens differed between the early and current periods (p,0.001); unboosted PI regimens (55.6%) were more common in the early and NNRTI regimens (46.4%) were more common in the current period. Overall, 78 % (95%CI 74, 82%) of patients achieved VS and trial participants were 16 % more likely to achieve VS (unadjusted RR 1.16, 95%CI 1.06, 1.27). Comparing trial to non-trial participants, VS differed by study period. In the early period, trial participants initiating HAART were significantly more likely to achieve VS than non-trial participants (adjusted RR 1.33; 95%CI 1.15, 1.54), but not in the current period (adjusted RR 0.98; 95%CI 0.87, 1.11). Conclusions: A clear clinical trial effect on suppression of HIV replication was observed in the early HAART period but not i

Interpersonal psychotherapy versus treatment as usual for PTSD and depression among Sichuan earthquake survivors: A randomized clinical trial

© 2014 Jiang et al.; licensee BioMed Central Ltd.Background: Without effective treatment, PTSD and depression can cause persistent disability in disaster-affected populations. Methods: Our objective was to test the efficacy of Interpersonal Psychotherapy

Moderators and mediators of the relationship between receiving versus being denied a pregnancy termination and subsequent binge drinking

BackgroundWomen who terminate pregnancies drink more subsequent to the pregnancy than women who give birth, including women who give birth after seeking to terminate a pregnancy.MethodsData are from the Turnaway Study, a prospective, longitudinal study of 956 women who sought to terminate pregnancies at 30 U.S. facilities. This paper focuses on the 452 women who received terminations just below facility gestational limits and 231 who were denied terminations because they presented just beyond facility gestational limits. This study examined whether baseline characteristics moderate the relationship between termination and subsequent binge drinking and whether stress, feelings about the pregnancy, and number of social roles mediate the relationship.ResultsOnly having had a previous live birth modified the termination-binge drinking relationship. Among women with previous live births, binge drinking was reduced among women carrying to term compared to terminating the pregnancy. Among women who had not had a previous live birth, however, the reduction in binge drinking among those denied termination was not sustained over time, and binge drinking of those who had and had not had terminations converged by 2.5 years. Neither stress, negative emotions, nor social roles mediated effects on binge drinking. Positive emotions at one week mediated effects on binge drinking at six months, although positive emotions at two years did not mediate effects on binge drinking at 2.5 years.ConclusionsHigher levels of binge drinking among those who terminate pregnancies do not appear due to stress or to negative emotions. Only parous women - and not nulliparous women - denied terminations experienced sustained reductions in binge drinking over time

The Tobacco Status Project (TSP): Study protocol for a randomized controlled trial of a Facebook smoking cessation intervention for young adults

© 2015 Ramo et al.Background: Tobacco use remains the leading cause of premature morbidity and mortality in the United States. Young adults are less successful at quitting, use cessation treatment less often than smokers of other ages, and can be a challe