2,364 research outputs found

    The Gounkoto Au deposit, West Africa: Constraints on ore genesis and volatile sources from petrological, fluid inclusion and stable isotope data

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    The Loulo–Gounkoto complex in the KĂ©dougou–KĂ©niĂ©ba Inlier hosts three multi-million ounce orogenic gold deposits, situated along the Senegal–Mali Shear Zone. This west Malian gold belt represents the largest West African orogenic gold district outside Ghana. The Gounkoto deposit is hosted to the south of the Gara and Yalea gold mines in the Kofi Series metasedimentary rocks. The ore body is structurally controlled and is characterised by sodic and phyllic alteration, As- and Fe-rich ore assemblages, with abundant magnetite, and overall enrichment in Fe–As–Cu–Au–Ag–W–Ni–Co–REE + minor Te–Pb–Se–Cd. Fluid inclusion analysis indicates that the deposit formed at P–T conditions of approximately 1.4 kbar and 340 °C and that two end member fluids were involved in mineralisation: (1) a moderate temperature (315–340 °C), low salinity (< 10 wt.% NaCl equiv.), low density (≀ 1 g·cm− 3), H2O–CO2–NaCl–H2S ± N2–CH4 fluid; (2) a high temperature (up to 445 °C), hypersaline (~ 40 wt.% NaCl equiv.), high density (~ 1.3 g·cm− 3), H2O–CO2–NaCl ± FeCl2 fluid. Partial mixing of these fluids within the Jog Zone at Gounkoto enhanced phase separation in the aqueo-carbonic fluid and acted as a precipitation mechanism for Au. These findings demonstrate the widespread, if heterogeneously distributed, nature of fluid mixing as an ore forming process in the Loulo–Gounkoto complex, operating over at least a 30 km strike length of the shear zone. Stable isotope analyses of ore components at Gounkoto indicate a dominant metamorphic source for H2O, H2S and CO2, and by extension Au. It thus can be reasoned that both the aqueo-carbonic and the hypersaline fluid at Gounkoto are of metamorphic origin and that the high levels of salinity in the brine are likely derived from evaporite dissolution

    DNA barcoding of Brazilian sea turtles (Testudines)

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    Five out of the seven recognized species of sea turtles (Testudines) occur on the Brazilian coast. The Barcode Initiative is an effort to undertake a molecular inventory of Earth biodiversity. Cytochrome Oxidase c subunit I (COI) molecular tags for sea turtle species have not yet been described. In this study, COI sequences for the five species of sea turtles that occur in Brazil were generated. These presented widely divergent haplotypes. All observed values were on the same range as those already described for other animal groups: the overall mean distance was 8.2%, the mean distance between families (Dermochelyidae and Cheloniidae) 11.7%, the mean intraspecific divergence 0.34%, and the mean distance within Cheloniidae 6.4%, this being 19-fold higher than the mean divergence observed within species. We obtained species-specific COI barcode tags that can be used for identifying each of the marine turtle species studied

    Kinome profiling reveals breast cancer heterogeneity and identifies targeted therapeutic opportunities for triple negative breast cancer

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    Our understanding of breast cancer heterogeneity at the protein level is limited despite proteins being the ultimate effectors of cellular functions. We investigated the heterogeneity of breast cancer (41 primary tumors and 15 breast cancer cell lines) at the protein and phosphoprotein levels to identify activated oncogenic pathways and developing targeted therapeutic strategies. Heterogeneity was observed not only across histological subtypes, but also within subtypes. Tumors of the Triple negative breast cancer (TNBC) subtype distributed across four different clusters where one cluster (cluster ii) showed high deregulation of many proteins and phosphoproteins. The majority of TNBC cell lines, particularly mesenchymal lines, resembled the cluster ii TNBC tumors. Indeed, TNBC cell lines were more sensitive than non-TNBC cell lines when treated with targeted inhibitors selected based on upregulated pathways in cluster ii. In line with the enrichment of the upregulated pathways with onco-clients of Hsp90, we found synergy in combining Hsp90 inhibitors with several kinase inhibitors, particularly Erk5 inhibitors. The combination of Erk5 and Hsp90 inhibitors was effective in vitro and in vivo against TNBC leading to upregulation of pro-apoptotic effectors. Our studies contribute to proteomic profiling and improve our understanding of TNBC heterogeneity to provide therapeutic opportunities for this disease

    Genetic diversity and structure of two species of Enyalius (Squamata: Leiosauridae) from neotropical biodiversity hotspots

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    Diversidade e estrutura genĂ©tica de duas espĂ©cies de Enyalius (Squamata: Leiosauridae) em hotspots neotropicais de biodiversidade. Os lagartos do gĂȘnero Enyalius sĂŁo endĂȘmicos da AmĂ©rica do Sul, sendo predominantemente encontrados no Cerrado e em fragmentos da Floresta AtlĂąntica. Este Ă© um gĂȘnero pouco estudado, e nĂŁo foram encontrados dados relacionados Ă  diversidade e Ă  estrutura genĂ©tica das espĂ©cies do gĂȘnero. Neste trabalho, investigamos a diversidade genĂ©tica de populaçÔes de E. bilineatus (N = 20) e E. perditus (N = 28), usando um fragmento de 234-pb do citocromo b, e comparamos as sequĂȘncias geradas com outras publicadas. Dezenove haplĂłtipos distintos foram encontrados (11 de E. perditus e oito de E. bilineatus), sendo oito deles novos registros. Os valores de diversidade haplotĂ­pica foram muito similares para as duas espĂ©cies (0.684 para E. perditus e 0.647 para E. bilineatus). A distĂąncia genĂ©tica entre as duas espĂ©cies foi de 20.3%, e as distĂąncias intraespecĂ­ficas foram 2.0% para E. perditus e 5.6% para E. bilineatus. Nossos dados sugerem que as populaçÔes de E. bilineatus sĂŁo altamente divergentes e que a espĂ©cie deve apresentar diversidade crĂ­ptica. Este Ă© o primeiro estudo medindo a diversidade genĂ©tica de espĂ©cies do gĂȘnero Enyalius oriundas de regiĂ”es consideradas hotspots da biodiversidade neotropical e apresenta dados relevantes para um melhor entendimento das relaçÔes inter e intrapopulacionais, assim como a distribuição das linhagens genĂ©ticas desse gĂȘnero endĂȘmico.Genetic diversity and structure of two species of Enyalius (Squamata: Leiosauridae) from neotropical biodiversity hotspots. Enyalius, a lizard genus endemic to South America, is mostly distributed in the remains of the Atlantic Forest and in the Cerrado. The genus has been the topic of a few studies but none has quantified the genetic diversity and structure within and among populations of Enyalius. The genetic diversity and structure of populations of E. bilineatus (N = 20) and E. perditus (N = 28) are examined using a 234-bp fragment of the cytochrome b gene and compared with the sequences reported in other published data. Nineteen distinct haplotypes (eleven for E. perditus and eight for E. bilineatus) were found, eight of which were recorded for the first time. The haplotype diversities are highly similar for both species (0.684 for E. perditus and 0.647 for E. bilineatus). The genetic distance between the two species is 20.3% and the distance within species is 2.0% and 5.6% for E. perditus and E. bilineatus, respectively. Our data suggest that populations of E. bilineatus are genetically divergent and may reveal cryptic diversity. This is the first study to quantify the genetic diversity of species of Enyalius from Neotropical biodiversity hotspots. These data facilitate a better understanding of both within and among population variation, and highlight the distribution of genetic lineages of an endemic and poorly studied genus

    Feminist identification, actions, beliefs and commitments at CSB/SJU

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    Does self-identification as a feminist, non-feminist, or non-labeler, affect actions, beliefs, and commitments regarding feminist ideals? Is there any dissonance between identifying with feminist beliefs and identifying with the feminist label? Will our data give us insight into education about feminist ideas at CSB/SJU (College of Saint Benedict and Saint John’s University)? Is the “feminist” label stigmatized on our campuses

    SDSS-IV from 2014 to 2016: A Detailed Demographic Comparison over Three Years

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    The Sloan Digital Sky Survey (SDSS) is one of the largest international astronomy organizations. We present demographic data based on surveys of its members from 2014, 2015 and 2016, during the fourth phase of SDSS (SDSS-IV). We find about half of SDSS-IV collaboration members were based in North America, a quarter in Europe, and the remainder in Asia and Central and South America. Overall, 26-36% are women (from 2014 to 2016), up to 2% report non-binary genders. 11-14% report that they are racial or ethnic minorities where they live. The fraction of women drops with seniority, and is also lower among collaboration leadership. Men in SDSS-IV were more likely to report being in a leadership role, and for the role to be funded and formally recognized. SDSS-IV collaboration members are twice as likely to have a parent with a college degree, than the general population, and are ten times more likely to have a parent with a PhD. This trend is slightly enhanced for female collaboration members. Despite this, the fraction of first generation college students (FGCS) is significant (31%). This fraction increased among collaboration members who are racial or ethnic minorities (40-50%), and decreased among women (15-25%). SDSS-IV implemented many inclusive policies and established a dedicated committee, the Committee on INclusiveness in SDSS (COINS). More than 60% of the collaboration agree that the collaboration is inclusive; however, collaboration leadership more strongly agree with this than the general membership. In this paper, we explain these results in full, including the history of inclusive efforts in SDSS-IV. We conclude with a list of suggested recommendations based on our findings, which can be used to improve equity and inclusion in large astronomical collaborations, which we argue is not only moral, but will also optimize their scientific output.Comment: 30 pages, 9 figures, accepted in PAS

    Multidrug resistant pulmonary tuberculosis treatment regimens and patient outcomes: an individual patient data meta-analysis of 9,153 patients.

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    Treatment of multidrug resistant tuberculosis (MDR-TB) is lengthy, toxic, expensive, and has generally poor outcomes. We undertook an individual patient data meta-analysis to assess the impact on outcomes of the type, number, and duration of drugs used to treat MDR-TB

    Dual antibiotic prevention bundle is associated with decreased surgical site infections

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    Background: Gynecologic oncology surgery is associated with a wide variation in surgical site infection risk. The optimal method for infection prevention in this heterogeneous population remains uncertain. Study design: A retrospective cohort study was performed to compare surgical site infection rates for patients undergoing hysterectomy over a 1-year period surrounding the implementation of an institutional infection prevention bundle. The bundle comprised pre-operative, intra-operative, and post-operative interventions including a dual-agent antibiotic surgical prophylaxis with cefazolin and metronidazole. Cohorts consisted of patients undergoing surgery during the 6 months prior to this intervention (pre-bundle) versus those undergoing surgery during the 6 months following the intervention (post-bundle). Secondary outcomes included length of stay, readmission rates, compliance measures, and infection microbiology. Data were compared with pre-specified one-sided exact test, Chi-square test, Fisher's exact test, or Kruskal-Wallis test as appropriate. Results: A total of 358 patients were included (178 PRE, 180 POST). Median age was 58 (range 23-90) years. The post-bundle cohort had a 58% reduction in surgical site infection rate, 3.3% POST vs 7.9% PRE (-4.5%, 95% CI -9.3% to -0.2%, p=0.049) as well as reductions in organ space infection, 0.6% POST vs 4.5% PRE (-3.9%, 95% CI -7.2% to -0.7%, p=0.019), and readmission rates, 2.2% POST vs 6.7% PRE (-4.5%, 95% CI -8.7% to -0.2%, p=0.04). Gram-positive, Gram-negative, and anaerobic bacteria were all prevalent in surgical site infection cultures. There were no monomicrobial infections in post-cohort cultures (0% POST vs 58% PRE, p=0.04). No infections contained methicillin-resistant Staphylococcus aureus. Conclusion: Implementation of a dual antibiotic infection prevention bundle was associated with a 58% reduction in surgical site infection rate after hysterectomy in a surgically diverse gynecologic oncology practice

    Cefuroxime Pharmacokinetics in Pediatric Cardiovascular Surgery Patients Undergoing Cardiopulmonary Bypass

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    Objectives The objective of this study was to determine the pharmacokinetics of cefuroxime in children undergoing cardiopulmonary bypass (CPB) for cardiovascular surgery. Design A prospective study. Setting A tertiary pediatric teaching hospital. Participants Infants and children undergoing CPB were enrolled in the study. Intervention An initial dose (mean, 24.2 ± 1.6 mg/kg) of cefuroxime was administered before surgical incision, and a second dose (mean, 14.4 ± 7.9 mg/kg) was administered in the CPB prime solution. Serial blood samples were obtained before, during, and after the CPB process. Samples were shipped on dry ice to the analytic laboratory and concentrations determined by a validated high-performance liquid chromatography method. A 2-compartment pharmacokinetic model was fitted to the data using maximum a priori–Bayesian estimation, with weight as a covariate. Monte Carlo simulations of a single-dose (25 mg/kg pre-CPB) approach and a 2-dose (25 mg/kg pre- and 12.5-mg/kg prime solution dose) approach were performed. Measurements and Main Results Fifteen subjects (9 males/6 females) were enrolled in the study, with median (range) age and weight of 11 (3-34) months and 9.5 (4.5-15.4) kg, respectively. The median (range) duration of CPB was 136 (71-243) minutes. Median and range cefuroxime pharmacokinetic parameters were as follows: maximum concentration (Cmax) dose, 1: 328 (150-512) ÎŒg/mL; systemic clearance, 0.050 (0.041-0.058) L/h/kg; steady-state volume of distribution, 0.213 (0.081-0.423) L/kg; volume of distribution in the central compartment, 0.081 (0.046-0.162) L/kg; and elimination half-life, 3.76 (1.03-6.81) hours. The median 8-hour post–dose-simulated cefuroxime concentrations were 26.5 and 16.0 mg/L for the 2-dose and single-dose regimens, respectively. Conclusion Manufacturers recommend that pediatric doses of cefuroxime (25-50 mg/kg) can be used in infants and children undergoing CPB to maintain adequate serum concentrations for surgical-site infection prophylaxis. A second intraoperative dose, administered through the CPB circuit, provides no additional prophylactic advantage

    The tropical rain belts with an annual cycle and a continent model intercomparison project: TRACMIP

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    This paper introduces the Tropical Rain belts with an Annual cycle and a Continent Model Intercomparison Project (TRACMIP). TRACMIP studies the dynamics of tropical rain belts and their response to past and future radiative forcings through simulations with 13 comprehensive and one simplified atmosphere models coupled to a slab ocean and driven by seasonally-varying insolation. Five idealised experiments, two with an aquaplanet setup and three with a setup with an idealized tropical continent, fill the space between prescribed-SST aquaplanet simulations and realistic simulations provided by CMIP5/6. The simulations reproduce key features of present-day climate and expected future climate change, including an annual-mean intertropical convergence zone (ITCZ) that is located north of the equator and Hadley cells and eddy-driven jets that are similar to present-day climate. Quadrupling CO2 leads to a northward ITCZ shift and preferential warming in Northern high-latitudes. The simulations show interesting CO2-induced changes in the seasonal excursion of the ITCZ and indicate a possible state-dependence of climate sensitivity. The inclusion of an idealized continent modulates both the control climate and the response to increased CO2; for example, it reduces the northward ITCZ shift associated with warming and, in some models, climate sensitivity. In response to eccentricity-driven orbital seasonal insolation changes, seasonal changes in oceanic rainfall are best characterized as a meridional dipole, while seasonal continental rainfall changes tend to be symmetric about the equator. This survey illustrates TRACMIP's potential to engender a deeper understanding of global and regional climate and to address questions on past and future climate
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