983 research outputs found
Modification and pathways of Southern Ocean Deep Waters in the Scotia Sea
An unprecedented high-quality, quasi-synoptic hydrographic data set collected during the ALBATROSS cruise along the rim of the Scotia Sea is examined to describe the pathways of the deep water masses flowing through the region, and to quantify changes in their properties as they cross the sea. Owing to sparse sampling of the northern and southern boundaries of the basin, the modification and pathways of deep water masses in the Scotia Sea had remained poorly documented despite their global significance. Weddell Sea Deep Water (WSDW) of two distinct types is observed spilling over the South Scotia Ridge to the west and east of the western edge of the Orkney Passage. The colder and fresher type in the west, recently ventilated in the northern Antarctic Peninsula, flows westward to Drake Passage along the southern margin of the Scotia Sea while mixing intensely with eastward-flowing Circumpolar Deep Water (CDW) of the antarctic circumpolar current (ACC). Although a small fraction of the other WSDW type also spreads westward to Drake Passage, the greater part escapes the Scotia Sea eastward through the Georgia Passage and flows into the Malvinas Chasm via a deep gap northeast of South Georgia. A more saline WSDW variety from the South Sandwich Trench may leak into the eastern Scotia Sea through Georgia Passage, but mainly flows around the Northeast Georgia Rise to the northern Georgia Basin. In Drake Passage, the inflowing CDW displays a previously unreported bimodal property distribution, with CDW at the Subantarctic Front receiving a contribution of deep water from the subtropical Pacific. This bimodality is eroded away in the Scotia Sea by vigorous mixing with WSDW and CDW from the Weddell Gyre. The extent of ventilation follows a zonation that can be related to the CDW pathways and the frontal anatomy of the ACC. Between the Southern Boundary of the ACC and the Southern ACC Front, CDW cools by 0.15°C and freshens by 0.015 along isopycnals. The body of CDW in the region of the Polar Front splits after overflowing the North Scotia Ridge, with a fraction following the front south of the Falkland Plateau and another spilling over the plateau near 49.5°W. Its cooling (by 0.07°C) and freshening (by 0.008) in crossing the Scotia Sea is counteracted locally by NADW entraining southward near the Maurice Ewing Bank. CDW also overflows the North Scotia Ridge by following the Subantarctic Front through a passage just east of Burdwood Bank, and spills over the Falkland Plateau near 53°W with decreased potential temperature (by 0.03°C) and salinity (by 0.004). As a result of ventilation by Weddell Sea waters, the signature of the Southeast Pacific Deep Water (SPDW) fraction of CDW is largely erased in the Scotia Sea. A modified form of SPDW is detected escaping the sea via two distinct routes only: following the Southern ACC Front through Georgia Passage; and skirting the eastern end of the Falkland Plateau after flowing through Shag Rocks Passage
Hidden benefits and risks of partial protection for coral reef fisheries
Partially protected areas are now the dominant global form of spatial management aimed at preserving ecosystem integrity and managing human use. However, most evaluations of their efficacy use only a narrow set of conservation indicators that reflect a fraction of ways in which protection can succeed or fail. In this paper, we examine three case studies of partially protected coral reef fishery systems to evaluate benefits and risks of their use as a management tool. We use data from community-based management arrangements in three Pacific Island countries to demonstrate three vignettes of how partial protection can boost fisheries production, enhance the ease with which fishers catch their prey, and alter the composition of fisheries yields. These changes in fisheries productivity, catchability, and vulnerability under partial protection carry substantial benefits for fishers. However, they also carry significant risks for ecosystems and fisheries livelihoods unless adaptively managed so as to confer the short to medium term benefits in resource performance without risking longer term sustainability
A single nucleotide polymorphism in the p27Kip1 gene is associated with primary patency of lower extremity vein bypass grafts
ObjectiveFactors responsible for the variability in outcomes after lower extremity vein bypass grafting (LEVBG) are poorly understood. Recent evidence has suggested that a single nucleotide polymorphism (SNP) in the promoter region of the p27Kip1 gene, a cell-cycle regulator, is associated with coronary in-stent restenosis. We hypothesized an association with vein graft patency.MethodsThis was a retrospective genetic association study nested within a prospective cohort of 204 patients from three referral centers undergoing LEVBG for claudication or critical ischemia. The main outcome measure was primary vein graft patency.ResultsAll patients were followed up for a minimum of 1 year with duplex graft surveillance (median follow-up, 893 days; interquartile range, 539-1315). Genomic DNA was isolated and SNP analysis for the p27Kip1-838C>A variants was performed. Allele frequencies were correlated with graft outcome using survival analysis and Cox proportional hazards modeling. The p27Kip1-838C>A allele frequencies observed were CA, 53%; CC, 30%; and AA, 17%, satisfying Hardy-Weinberg equilibrium. Race (P = .025) and history of coronary artery disease (P = .027) were different across the genotypes; all other baseline variables were similar. Primary graft patency was greater among patients with the -838AA genotype (75% AA vs 55% CA/CC at 3 years; P = .029). In a Cox proportional hazards model including age, sex, race, diabetes, critical limb ischemia, redo (vs primary) bypass, vein type, and baseline C-reactive protein level, the p27Kip1-838AA genotype was significantly associated with higher graft patency (hazard ratio for failure, 0.4; 95% confidence interval, 0.17-0.93). Genotype was also associated with early (0-1 month) changes in graft lumen diameter by ultrasound imaging.ConclusionsThese data suggest that the p27Kip1-838C>A SNP is associated with LEVBG patency and, together with previous reports, underscore a central role for p27Kip1 in the generic response to vascular injury
Experimental and modeled thermoregulatory costs of repeated sublethal oil exposure in the Double-crested Cormorant, \u3ci\u3ePhalacrocorax auritus\u3c/i\u3e
To fully understand the impact of oil exposure, it is important to understand sublethal effects like how increased thermoregulatory costs may affect survival and reproduction. However, it is difficult and time-consuming to measure these effects in wild animals. We present a novel use of a bioenergetics model, Niche Mapper™, to estimate thermoregulatory impacts of oiling, using data from captive Double-crested Cormorants (Phalacrocorax auritus) experimentally exposed to oil. Oiled cormorants had significant increases in surface body temperatures following exposure. Niche Mapper accurately predicted surface temperatures and metabolic rates for unoiled and oiled cormorants and predicted 13–18% increased daily energetic demands due to increased thermoregulatory costs of oiling, consistent with increased food consumption observed in experimentally oiled cormorants. We show that Niche Mapper can provide valuable insight into sublethal oiling effects by quantifying the extent to which thermoregulatory costs divert energy resources away from important life processes like maintenance, reproduction and migration
Society for Cardiovascular Magnetic Resonance (SCMR) guidance for the practice of cardiovascular magnetic resonance during the COVID-19 pandemic
The aim of this document is to provide general guidance and specific recommendations on the practice of cardiovascular magnetic resonance (CMR) in the era of the COVID-19 pandemic. There are two major considerations. First, continued urgent and semi-urgent care for the patients who have no known active COVID-19 should be provided in a safe manner for both patients and staff. Second, when necessary, CMR on patients with confirmed or suspected active COVID-19 should focus on the specific clinical question with an emphasis on myocardial function and tissue characterization while optimizing patient and staff safety
Towards a consensus-based classification of childhood arterial ischemic stroke.
Background and purposeThe implementation of uniform nomenclature and classification in adult arterial ischemic stroke (AIS) has been critical for defining outcomes and recurrence risks according to etiology and in developing risk-stratified treatments. In contrast, current classification and nomenclature in childhood AIS are often overlapping or contradictory. Our purpose was to develop a comprehensive consensus-based classification system for childhood AIS.MethodsUsing a modified-Delphi method, members of the International Pediatric Stroke Study (IPSS) developed the Childhood AIS Standardized Classification And Diagnostic Evaluation (CASCADE) criteria. Two groups of pediatric stroke specialists from the IPSS classified 7 test cases using 2 methods each: (1) classification typical of the individual clinician's current clinical practice; and (2) classification based on the CASCADE criteria. Group 1 underwent in-person training in the utilization of the CASCADE criteria. Group 2 classified the same cases via an online survey, including definitions but without training. Inter-rater reliability (IRR) was assessed via multi-rater unweighted κ-statistic.ResultsIn Group 1 (with training), IRR was improved using CASCADE criteria (κ=0.78, 95% CI=[0.49, 0.94]), compared with typical clinical practice (κ=0.40, 95% CI=[0.11, 0.60]). In Group 2 (without training), IRR was lower than among trained raters (κ=0.61, 95% CI=[0.29, 0.77]), but higher than current practice (κ=0.23, 95% CI=[0.03, 0.36]).ConclusionsA new, consensus-based classification system for childhood AIS, the CASCADE criteria, can be used to classify cases with good IRR. These preliminary findings suggest that the CASCADE criteria may be particularity useful in the setting of prospective multicenter studies in childhood-onset AIS, where standardized training of investigators is feasible
Opsin Repertoire and Expression Patterns in Horseshoe Crabs: Evidence from the Genome of Limulus polyphemus (Arthropoda: Chelicerata)
Horseshoe crabs are xiphosuran chelicerates, the sister groupto arachnids. As such, they are important for understandingthemost recent common ancestor of Euchelicerata and the evolution and diversification of Arthropoda. Limulus polyphemus is the most investigated of the four extant species of horseshoe crabs, and the structure and function of its visual system have long been a major focus of studies critical for understanding the evolution of visual systems in arthropods. Likewise, studies of genes encoding Limulus opsins, the protein component of the visual pigments, are critical for understanding opsin evolution and diversification among chelicerates, where knowledge of opsins is limited, and more broadly among arthropods. In the present study, we sequenced and assembled a high quality nuclear genomic sequence of L. polyphemus and used these data to annotate the full repertoire of Limulus opsins.Weconducted a detailed phylogenetic analysis of Limulus opsins, including using gene structure and synteny information to identify relationships among different opsin classes.We used our phylogeny to identify significant genomic events that shaped opsin evolution and therefore the visual systemof Limulus.We also describe the tissue expression patterns of the 18 opsins identified and show that transcripts encoding a number, including a peropsin, are present throughout the central nervous system. In additionto significantly extending our understanding of photosensitivity in Limulus and providing critical insight into the genomic evolution of horseshoe crab opsins, this work provides a valuable genomic resource for addressing myriad questions related to xiphosuran physiology and arthropod evolution
Engaging with community researchers for exposure science: lessons learned from a pesticide biomonitoring study
A major challenge in biomonitoring studies with members of the general public is ensuring their continued involvement throughout the necessary length of the research. The paper presents evidence on the use of community researchers, recruited from local study areas, as a mechanism for ensuring effective recruitment and retention of farmer and resident participants for a pesticides biomonitoring study. The evidence presented suggests that community researchers' abilities to build and sustain trusting relationships with participants enhanced the rigour of the study as a result of their on-the-ground responsiveness and flexibility resulting in data collection beyond targets expected
Society for Cardiovascular Magnetic Resonance (SCMR) guidance for re-activation of cardiovascular magnetic resonance practice after peak phase of the COVID-19 pandemic
During the peak phase of the COVID-19 pandemic, alterations of standard operating procedures were necessary for health systems to protect patients and healthcare workers and ensure access to vital hospital resources. As the peak phase passes, re-activation plans are required to safely manage increasing clinical volumes. In the context of cardiovascular magnetic resonance (CMR), re-activation objectives include continued performance of urgent CMR studies and resumption of CMR in patients with semi-urgent and elective indications in an environment that is safe for both patients and health care workers
Attitudes toward Precision Treatment of Smoking in the Southern Community Cohort Study
Background: Precision interventions using biological data may enhance smoking treatment, yet are understudied among smokers who are disproportionately burdened by smoking-related disease. Methods: We surveyed smokers in the NCI-sponsored Southern Community Cohort Study, consisting primarily of African-American, low-income adults. Seven items assessed attitudes toward aspects of precision smoking treatment, from undergoing tests to acting on results. Items were dichotomized as favorable (5 = strongly agree/4 = agree) versus less favorable (1 = strongly disagree/2 = disagree/3 = neutral); a summary score reflecting generalized attitudes was also computed. Multivariable logistic regression tested independent associations of motivation (precontemplation, contemplation, and preparation) and confidence in quitting (low, medium, and high) with generalized attitudes, controlling for sociodemographic factors and nicotine dependence. Results: More than 70% of respondents endorsed favorable generalized attitudes toward precision medicine, with individual item favorability ranging from 64% to 83%. Smokers holding favorable generalized attitudes reported higher income and education (P \u3c 0.05). Predicted probabilities of favorable generalized attitudes ranged from 63% to 75% across motivation levels [contemplation vs. precontemplation: adjusted odds ratio (AOR) = 2.10, 95% confidence interval (CI), 1.36–3.25, P = 0.001; preparation vs. precontemplation: AOR = 1.83, 95% CI, 1.20–2.78, P = 0.005; contemplation vs. preparation: AOR = 1.15, 95% CI, 0.75–1.77, P = 0.52] and from 59% to 78% across confidence (medium vs. low: AOR = 1.91, 95% CI, 1.19–3.07, P = 0.007; high vs. low: AOR = 2.62, 95% CI, 1.68–4.10, P \u3c 0.001; medium vs. high: AOR = 0.73, 95% CI, 0.48–1.11, P = 0.14). Conclusions: Among disproportionately burdened community smokers, most hold favorable attitudes toward precision smoking treatment. Individuals with lower motivation and confidence to quit may benefit from additional intervention to engage with precision smoking treatment. Impact: Predominantly favorable attitudes toward precision smoking treatment suggest promise for future research testing their effectiveness and implementation
- …