105 research outputs found

    The three-dimensional structure of Kilauea Volcano, Hawaii, from travel time tomography

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    A linear, travel time tomography study of the most active shield volcano of the world, Kilauea Volcano, Hawaii, was undertaken to determine the lateral heterogeneities produced by its intricate magmatic and tectonic environment. Kilauea provides an ideal setting to do tomography because of its dense seismograph array and many local earthquakes that allow excellent ray coverage of complex subsurface features. Local P wave data from ∼ 12,295 events were inverted using a one-dimensional layered velocity model. Inversions were done for two cell sizes (5×5×5 km and 1×1×1 km) to resolve structural regions on different length scales. This study provided a view of the average velocity variations relative to a one-dimensional velocity model. Analysis and interpretation of the tomographic images allowed us to infer the following model. The main shallow magma reservoir is delineated by a slow velocity region southeast of the summit from 0 to 2 km depth. There is a distinct high velocity region centered northwest of the summit from 0 to 2 km depth that represents a cap of dense, intrusive dikes surrounding the magma chamber. We suggest that the shallow reservoir is a narrow, compartmentalized region of sills and dikes, centered just south-southeast of Halemaumau caldera. Below the main reservoir, the summit is imaged as a slightly fast region from 5 to 10 km in the coarse model indicating that the main conduit is structurally defined by an intrusive dike complex until about 10 km. The rift zones of Kilauea are imaged as major, high velocity entities, widening to the south with depth until 6 km. These fast anomalies are related to the sheeted dike complexes along the rifts. On a finer scale, slow anomalies suggest the presence of magma pockets centered at 0–2 km depth beneath Mauna Ulu, Makaopuhi and Puu Oo, along the east rift zone (ERZ). Two significant high velocity regions along the lower ERZ near Kalalua and Kaliu are inferred to represent intrusive barriers to magma injection along the shallow (0–4 km) ERZ conduit. The southwest rift zone may have an intrusive barrier related to a high velocity region just southwest of Mauna Iki. The Hilina and Kaoiki fault zones are imaged as slow features at shallow depths (< 5 km) related to the open fractures and scarps along the normal faults. The Koae fault system is imaged as a slightly fast shallow structure (< 6 km) possibly related to intrusive diking from the adjacent rift zones that fill and may even induce the extensional structures associated with this complex fault zone. Continued inversions with the immense amount of seismic data collected for Hawaiian events will allow the detailed development of a three-dimensional structural model for Kilauea. Such a model will be extremely useful to seismologists and petrologists alike for understanding the tectonic growth and magmatic evolution of this dynamic shield volcano

    word~river literary review (2009)

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    wordriver is a literary journal dedicated to the poetry, short fiction and creative nonfiction of adjuncts and part-time instructors teaching in our universities, colleges, and community colleges. Our premier issue was published in Spring 2009. We are always looking for work that demonstrates the creativity and craft of adjunct/part-time instructors in English and other disciplines. We reserve first publication rights and onetime anthology publication rights for all work published. We define adjunct instructors as anyone teaching part-time or full-time under a semester or yearly contract, nationwide and in any discipline. Graduate students teaching under part-time contracts during the summer or who have used up their teaching assistant time and are teaching with adjunct contracts for the remainder of their graduate program also are eligible.https://digitalscholarship.unlv.edu/word_river/1002/thumbnail.jp

    Coronary Atherosclerosis in Indigenous South American Tsimane: A Cross-Sectional Cohort Study

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    Background—Conventional coronary artery disease risk factors might potentially explain at least 90% of the attributable risk of coronary artery disease. To better understand the association between the pre-industrial lifestyle and low prevalence of coronary artery disease risk factors, we examined the Tsimane, a Bolivian population living a subsistence lifestyle of hunting, gathering, fishing, and farming with few cardiovascular risk factors, but high infectious inflammatory burden. Methods—We did a cross-sectional cohort study including all individuals who self-identified as Tsimane and who were aged 40 years or older. Coronary atherosclerosis was assessed by coronary artery calcium (CAC) scoring done with non-contrast CT in Tsimane adults. We assessed the difference between the Tsimane and 6814 participants from the Multi-Ethnic Study of Atherosclerosis (MESA). CAC scores higher than 100 were considered representative of significant atherosclerotic disease. Tsimane blood lipid and inflammatory biomarkers were obtained at the time of scanning, and in some patients, longitudinally. Findings—Between July 2, 2014, and Sept 10, 2015, 705 individuals, who had data available for analysis, were included in this study. 596 (85%) of 705 Tsimane had no CAC, 89 (13%) had CAC scores of 1–100, and 20 (3%) had CAC scores higher than 100. For individuals older than age 75 years, 31 (65%) Tsimane presented with a CAC score of 0, and only four (8%) had CAC scores of 100 or more, a five-fold lower prevalence than industrialised populations (p≤0-0001 for all age categories of MESA). Mean LDL and HDL cholesterol concentrations were 2.35 mmol/L (91 mg/dL) and 1.0 mmol/L (39.5 mg/dL), respectively; obesity, hypertension, high blood sugar, and regular cigarette smoking were rare. High- sensitivity C-reactive protein was elevated beyond the clinical cutoff of 3.0 mg/dL in 360 (51%) Tsimane participants. Interpretation—Despite a high infectious inflammatory burden, the Tsimane, a forager-horticulturalist population of the Bolivian Amazon with few coronary artery disease risk factors, have the lowest reported levels of coronary artery disease of any population recorded to date. These findings suggest that coronary atherosclerosis can be avoided in most people by achieving a lifetime with very low LDL, low blood pressure, low glucose, normal body-mass index, no smoking, and plenty of physical activity. The relative contributions of each are still to be determined

    Prevalence of Dementia and Mild Cognitive Impairment in Indigenous Bolivian Forager-Horticulturalists

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    Introduction We evaluated the prevalence of dementia and mild cognitive impairment (MCI) in indigenous Tsimane and Moseten, who lead a subsistence lifestyle. Methods Participants from population-based samples ≥ 60 years of age (n = 623) were assessed using adapted versions of the Modified Mini-Mental State Examination, informant interview, longitudinal cognitive testing and brain computed tomography (CT) scans. Results Tsimane exhibited five cases of dementia (among n = 435; crude prevalence = 1.2%, 95% confidence interval [CI]: 0.4, 2.7); Moseten exhibited one case (among n = 169; crude prevalence = 0.6%, 95% CI: 0.0, 3.2), all age ≥ 80 years. Age-standardized MCI prevalence was 7.7% (95% CI: 5.2, 10.3) in Tsimane and 9.8% (95% CI: 4.9, 14.6) in Moseten. Cognitive impairment was associated with visuospatial impairments, parkinsonian symptoms, and vascular calcification in the basal ganglia. Discussion The prevalence of dementia in this cohort is among the lowest in the world. Widespread intracranial medial arterial calcifications suggest a previously unrecognized, non-Alzheimer\u27s disease (AD) dementia phenotype

    Whole-genome sequencing reveals host factors underlying critical COVID-19

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    Critical Covid-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalisation2-4 following SARS-CoV-2 infection. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from critically-ill cases with population controls in order to find underlying disease mechanisms. Here, we use whole genome sequencing in 7,491 critically-ill cases compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical Covid-19. We identify 16 new independent associations, including variants within genes involved in interferon signalling (IL10RB, PLSCR1), leucocyte differentiation (BCL11A), and blood type antigen secretor status (FUT2). Using transcriptome-wide association and colocalisation to infer the effect of gene expression on disease severity, we find evidence implicating multiple genes, including reduced expression of a membrane flippase (ATP11A), and increased mucin expression (MUC1), in critical disease. Mendelian randomisation provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5, CD209) and coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of Covid-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication, or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between critically-ill cases and population controls is highly efficient for detection of therapeutically-relevant mechanisms of disease

    Whole-genome sequencing reveals host factors underlying critical COVID-19

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    Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care(1) or hospitalization(2-4) after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes-including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)-in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease. © 2022, The Author(s)

    Genomic epidemiology of SARS-CoV-2 in a UK university identifies dynamics of transmission

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    AbstractUnderstanding SARS-CoV-2 transmission in higher education settings is important to limit spread between students, and into at-risk populations. In this study, we sequenced 482 SARS-CoV-2 isolates from the University of Cambridge from 5 October to 6 December 2020. We perform a detailed phylogenetic comparison with 972 isolates from the surrounding community, complemented with epidemiological and contact tracing data, to determine transmission dynamics. We observe limited viral introductions into the university; the majority of student cases were linked to a single genetic cluster, likely following social gatherings at a venue outside the university. We identify considerable onward transmission associated with student accommodation and courses; this was effectively contained using local infection control measures and following a national lockdown. Transmission clusters were largely segregated within the university or the community. Our study highlights key determinants of SARS-CoV-2 transmission and effective interventions in a higher education setting that will inform public health policy during pandemics.</jats:p

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
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