Suppressed basal melting in the eastern Thwaites Glacier grounding zone

This work is from the MELT project, a component of the International Thwaites Glacier Collaboration (ITGC). Support from the National Science Foundation (NSF, grant no. 1739003) and the Natural Environment Research Council (NERC, grant no. NE/S006656/1). Logistics provided by NSF U.S. Antarctic Program and NERC British Antarctic Survey. The ship-based CTD data were supported by the ITGC TARSAN project (NERC grant nos. NE/S006419/1 and NE/S006591/1; NSF grant no. 1929991). ITGC contribution no. ITGC 047.Thwaites Glacier is one of the fastest-changing ice–ocean systems in Antarctica1,2,3. Much of the ice sheet within the catchment of Thwaites Glacier is grounded below sea level on bedrock that deepens inland4, making it susceptible to rapid and irreversible ice loss that could raise the global sea level by more than half a metre2,3,5. The rate and extent of ice loss, and whether it proceeds irreversibly, are set by the ocean conditions and basal melting within the grounding-zone region where Thwaites Glacier first goes afloat3,6, both of which are largely unknown. Here we show—using observations from a hot-water-drilled access hole—that the grounding zone of Thwaites Eastern Ice Shelf (TEIS) is characterized by a warm and highly stable water column with temperatures substantially higher than the in situ freezing point. Despite these warm conditions, low current speeds and strong density stratification in the ice–ocean boundary layer actively restrict the vertical mixing of heat towards the ice base7,8, resulting in strongly suppressed basal melting. Our results demonstrate that the canonical model of ice-shelf basal melting used to generate sea-level projections cannot reproduce observed melt rates beneath this critically important glacier, and that rapid and possibly unstable grounding-line retreat may be associated with relatively modest basal melt rates.Publisher PDFPeer reviewe

Effect of nesiritide in patients with acute decompensated heart failure

Background Nesiritide is approved in the United States for early relief of dyspnea in patients with acute heart failure. Previous meta-analyses have raised questions regarding renal toxicity and the mortality associated with this agent. Methods We randomly assigned 7141 patients who were hospitalized with acute heart failure to receive either nesiritide or placebo for 24 to 168 hours in addition to standard care. Coprimary end points were the change in dyspnea at 6 and 24 hours, as measured on a 7-point Likert scale, and the composite end point of rehospitalization for heart failure or death within 30 days. Results Patients randomly assigned to nesiritide, as compared with those assigned to placebo, more frequently reported markedly or moderately improved dyspnea at 6 hours (44.5% vs. 42.1%, P = 0.03) and 24 hours (68.2% vs. 66.1%, P = 0.007), but the prespecified level for significance (P≤0.005 for both assessments or P≤0.0025 for either) was not met. The rate of rehospitalization for heart failure or death from any cause within 30 days was 9.4% in the nesiritide group versus 10.1% in the placebo group (absolute difference, −0.7 percentage points; 95% confidence interval [CI], −2.1 to 0.7; P = 0.31). There were no significant differences in rates of death from any cause at 30 days (3.6% with nesiritide vs. 4.0% with placebo; absolute difference, −0.4 percentage points; 95% CI, −1.3 to 0.5) or rates of worsening renal function, defined by more than a 25% decrease in the estimated glomerular filtration rate (31.4% vs. 29.5%; odds ratio, 1.09; 95% CI, 0.98 to 1.21; P = 0.11). Conclusions Nesiritide was not associated with an increase or a decrease in the rate of death and rehospitalization and had a small, nonsignificant effect on dyspnea when used in combination with other therapies. It was not associated with a worsening of renal function, but it was associated with an increase in rates of hypotension. On the basis of these results, nesiritide cannot be recommended for routine use in the broad population of patients with acute heart failure. (Funded by Scios; ClinicalTrials.gov number, NCT00475852.

Suppressed basal melting in the eastern Thwaites Glacier grounding zone

Thwaites Glacier is one of the fastest-changing ice–ocean systems in Antarctica1,2,3. Much of the ice sheet within the catchment of Thwaites Glacier is grounded below sea level on bedrock that deepens inland4, making it susceptible to rapid and irreversible ice loss that could raise the global sea level by more than half a metre2,3,5. The rate and extent of ice loss, and whether it proceeds irreversibly, are set by the ocean conditions and basal melting within the grounding-zone region where Thwaites Glacier first goes afloat3,6, both of which are largely unknown. Here we show—using observations from a hot-water-drilled access hole—that the grounding zone of Thwaites Eastern Ice Shelf (TEIS) is characterized by a warm and highly stable water column with temperatures substantially higher than the in situ freezing point. Despite these warm conditions, low current speeds and strong density stratification in the ice–ocean boundary layer actively restrict the vertical mixing of heat towards the ice base7,8, resulting in strongly suppressed basal melting. Our results demonstrate that the canonical model of ice-shelf basal melting used to generate sea-level projections cannot reproduce observed melt rates beneath this critically important glacier, and that rapid and possibly unstable grounding-line retreat may be associated with relatively modest basal melt rates

Discovery and functional prioritization of Parkinson's disease candidate genes from large-scale whole exome sequencing.

BACKGROUND: Whole-exome sequencing (WES) has been successful in identifying genes that cause familial Parkinson's disease (PD). However, until now this approach has not been deployed to study large cohorts of unrelated participants. To discover rare PD susceptibility variants, we performed WES in 1148 unrelated cases and 503 control participants. Candidate genes were subsequently validated for functions relevant to PD based on parallel RNA-interference (RNAi) screens in human cell culture and Drosophila and C. elegans models. RESULTS: Assuming autosomal recessive inheritance, we identify 27 genes that have homozygous or compound heterozygous loss-of-function variants in PD cases. Definitive replication and confirmation of these findings were hindered by potential heterogeneity and by the rarity of the implicated alleles. We therefore looked for potential genetic interactions with established PD mechanisms. Following RNAi-mediated knockdown, 15 of the genes modulated mitochondrial dynamics in human neuronal cultures and four candidates enhanced α-synuclein-induced neurodegeneration in Drosophila. Based on complementary analyses in independent human datasets, five functionally validated genes-GPATCH2L, UHRF1BP1L, PTPRH, ARSB, and VPS13C-also showed evidence consistent with genetic replication. CONCLUSIONS: By integrating human genetic and functional evidence, we identify several PD susceptibility gene candidates for further investigation. Our approach highlights a powerful experimental strategy with broad applicability for future studies of disorders with complex genetic etiologies

People, Professionals, and Profit Centers: The Connection between Lawyer Well-Being and Employer Values

Concerns about the well-being of lawyers are rising against the backdrop of a transforming legal profession, one which many observe to be operating more like a business in recent decades. However, aspects of this change, such as lawyers perceiving that their employers value financial performance and productivity above all else, could be associated with unhealthy work practices detrimental to lawyer well-being. The objective of the present study was to determine whether the perceived values of employers were differentially associated with lawyer well-being, stress, and work overcommitment. To this end, 1959 participants from a random sample of attorneys completed a survey designed to assess well-being. Participants were separated into one of three groups based on what they perceived their employer to value most about them: (1) Professionalism/Individual (professionalism and skills), (2) Financial Worth/Availability (revenue generation and availability), and (3) No Value/No Feedback (feeling unvalued or lacking feedback) and compared on measures of mental and physical health (SF-12), stress (Perceived Stress Scale), and work over commitment (Effort–Reward Imbalance Questionnaire). MANOVA results indicated that mental health, stress, and work overcommitment significantly differed between groups in the following rank order: Professionalism/Individual > Financial Worth/Availability > No Value/No Feedback. Overall, our findings paint a compelling picture of a health hierarchy within legal work environments, one that appears to be linked to employer values

Risk pathways contributing to the alcohol harm paradox: socioeconomic deprivation confers susceptibility to alcohol dependence greater exposure to aversive experience, internalizing symptoms and drinking to cope.

Socioeconomic deprivation is associated with greater alcohol problems despite lower alcohol consumption, but the mechanisms underpinning this alcohol harm paradox remain obscure. Fragmented published evidence collectively supports a multistage causal risk pathway wherein socioeconomic deprivation increases the probability of exposure to aversive experience, which promotes internalizing symptoms (depression and anxiety), which promotes drinking alcohol to cope with negative affect, which in turn accelerates the transition from alcohol use to dependence. To evaluate this proposed risk pathway, 219 hazardous drinkers from an undergraduate population completed questionnaires assessing these constructs in a single, cross sectional, online survey. Partial correlation coefficients revealed that each variable showed the strongest unique association with the next variable in the proposed multistage model, when adjusting for the other variables. Bootstrapped serial mediation analysis revealed that the indirect pathway linking all the variables in the proposed serial order was significant, while all other permutations were non-significant. Network centrality analysis corroborated the serial order of this indirect path. Finally, risk ratios estimated by categorizing the variables suggested that socioeconomic deprivation increased the risk of aversive experience by 32%, which increased the risk of internalizing symptoms by 180%, which increased the risk of drinking to cope by 64%, which increased susceptibility to alcohol dependence by 59%. These preliminary findings need to be corroborated by future research, nevertheless, they call for prevention strategies founded on social justice and the minimization of aversive experience in socially deprived individuals to mitigate mental health problems, maladaptive coping and addiction

Stressed, Lonely, and Overcommitted: Predictors of Lawyer Suicide Risk

Suicide is a significant public health concern, and lawyers have been shown to have an elevated risk for contemplating it. In this study, we sought to identify predictors of suicidal ideation in a sample consisting of 1962 randomly selected lawyers. Using logistic regression analysis, we found that high levels of work overcommitment, high levels of perceived stress, loneliness as measured by the UCLA loneliness scale, and being male were all significantly associated with an increased risk of suicidal ideation. These results suggest that interventions aimed at reducing work overcommitment, stress, and loneliness, and addressing gender-specific risk factors, may be effective in reducing the risk of suicidal ideation among lawyers. Further research is needed to expand upon these findings and to develop and test interventions specifically tailored to the needs of this population