303 research outputs found

    Watershed-Scale Drivers of Air-Water CO2 Exchanges in Two Lagoonal North Carolina (USA) Estuaries

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    Riverine loading of nutrients and organic matter act in concert to modulate CO2 fluxes in estuaries, yet quantitative relationships between these factors remain poorly defined. This study explored watershed-scale mechanisms responsible for the relatively low CO2 fluxes observed in two microtidal, lagoonal estuaries. Air-water CO2 fluxes were quantified with 74 high-resolution spatial surveys in the neighboring New River Estuary (NewRE) and Neuse River Estuary (NeuseRE), North Carolina, which experience a common climatology but differ in marine versus riverine influence. Annually, both estuaries were relatively small sources of CO2 to the atmosphere, 12.5 and 16.3mmolCm(-2)d(-1) in the NeuseRE and NewRE, respectively. Large-scale pCO(2) variations were driven by changes in freshwater age, which modulates nutrient and organic carbon supply and phytoplankton flushing. Greatest pCO(2) undersaturation was observed at intermediate freshwater ages, between 2 and 3weeks. Biological controls on CO2 fluxes were obscured by variable inputs of river-borne CO2, which drove CO2 degassing in the river-dominated NeuseRE. Internally produced CO2 exceeded river-borne CO2 in the marine-dominated NewRE, suggesting that net ecosystem heterotrophy, rather than riverine inputs, drove CO2 fluxes in this system. Variations in riverine alkalinity and inorganic carbon loading caused zones of minimum buffering capacity to occur at different locations in each estuary, enhancing the sensitivity of estuarine inorganic C chemistry to acidification. Although annual CO2 fluxes were similar between systems, watershed-specific hydrologic factors led to disparate controls on internal carbonate chemistry, which can influence ecosystem biogeochemical cycling, trophic state, and response to future perturbations. Plain Language Summary Estuaries release nearly as much CO2 to the atmosphere as is taken up over the continental shelf. However, estuarine emissions vary greatly across space and time, contributing significantly to the uncertainty of global carbon budgets. In this study, we assess spatial and temporal variability in CO2 emissions from adjacent estuaries in North Carolina, USA. These emissions varied across seasons and river discharge conditions but were relatively small when assessed as annual averages. Freshwater age (time freshwater spends in estuary before being flushed to ocean) was an important driver of CO2 dynamics in both estuaries, due to its role in regulating nutrient, DOC, and DIC supply while also affecting the rate at which phytoplankton are flushed from the system. While the relationship between freshwater age and CO2 was similar for both estuaries, we show that the various external and internal inputs of CO2 were quite different. Riverine CO2 inputs drove CO2 emissions in the river-dominated estuary, while internally produced CO2 (from community respiration) was more important in the marine-dominated estuary. We also demonstrate that poorly buffered regions in both estuaries are particularly vulnerable to acidification, with potentially negative impacts on calcifying organisms

    The impact of acute calcium intake on bone turnover markers during a training day in elite male rowers

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    Introduction: While an acute exercise session typically increases bone turnover markers (BTM), the impact of subsequent sessions and the interaction with pre-exercise calcium intake remains unclear despite the application to the ‘real life’ training of many competitive athletes. Methods: Using a randomized crossover design, elite male rowers (n = 16) completed two trials, a week apart, consisting of two 90-minute rowing ergometer sessions (Ex1, Ex2) separated by 150 minutes. Prior to each trial, participants consumed a high (CAL: ~1000 mg) or isocaloric low (CON: \u3c 10 mg) calcium meal. Biochemical markers including parathyroid hormone: PTH; serum ionised calcium (iCa) and bone turnover markers (C-terminal telopeptide of type I collagen: ÎČ-CTX-I; osteocalcin: OC) were monitored from baseline to 3 hours post Ex2. Results: While each session caused perturbances of serum iCa, CAL maintained calcium concentrations above those of CON for most time points, 4.5 and 2.4 % higher post EX1 and EX2 respectively. The decrease in iCa in CON was associated with an elevation of blood PTH (p \u3c 0.05) and ÎČ-CTX-I (p \u3c 0.0001) over this period of repeated training sessions and their recovery, particularly during and after Ex2. Pre-exercise intake of calcium-rich foods lowered BTM over the course of a day with several training sessions. Conclusions: Pre-exercise intake of a calcium-rich meal prior to training sessions undertaken within the same day had a cumulative and prolonged effect on the stabilisation of blood iCa during exercise. In turn, this reduced the post-exercise PTH response, potentially attenuating the increase in markers of bone resorption. Such practical strategies may be integrated into the athlete’s overall sports nutrition plan, with the potential to safeguard long term bone health and reduce the risk of bone stress injuries

    Analysis of lesion localisation at colonoscopy: outcomes from a multi-centre U.K. study

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    Background: Colonoscopy is currently the gold standard for detection of colorectal lesions, but may be limited in anatomically localising lesions. This audit aimed to determine the accuracy of colonoscopy lesion localisation, any subsequent changes in surgical management and any potentially influencing factors. Methods: Patients undergoing colonoscopy prior to elective curative surgery for colorectal lesion/s were included from 8 registered U.K. sites (2012–2014). Three sets of data were recorded: patient factors (age, sex, BMI, screener vs. symptomatic, previous abdominal surgery); colonoscopy factors (caecal intubation, scope guide used, colonoscopist accreditation) and imaging modality. Lesion localisation was standardised with intra-operative location taken as the gold standard. Changes to surgical management were recorded. Results: 364 cases were included; majority of lesions were colonic, solitary, malignant and in symptomatic referrals. 82% patients had their lesion/s correctly located at colonoscopy. Pre-operative CT visualised lesion/s in only 73% of cases with a reduction in screening patients (64 vs. 77%; p = 0.008). 5.2% incorrectly located cases at colonoscopy underwent altered surgical management, including conversion to open. Univariate analysis found colonoscopy accreditation, scope guide use, incomplete colonoscopy and previous abdominal surgery significantly influenced lesion localisation. On multi-variate analysis, caecal intubation and scope guide use remained significant (HR 0.35, 0.20–0.60 95% CI and 0.47; 0.25–0.88, respectively). Conclusion: Lesion localisation at colonoscopy is incorrect in 18% of cases leading to potentially significant surgical management alterations. As part of accreditation, colonoscopists need lesion localisation training and awareness of when inaccuracies can occur

    Association Between Choice of Radical Prostatectomy, External Beam Radiotherapy, Brachytherapy, or Active Surveillance and Patient-Reported Quality of Life Among Men With Localized Prostate Cancer

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    Importance Patients diagnosed with localized prostate cancer have to decide among treatment strategies that may differ in their likelihood of adverse effects. Objective To compare quality of life (QOL) after radical prostatectomy, external beam radiotherapy, and brachytherapy vs active surveillance. Design, Setting, and Participants Population-based prospective cohort of 1141 men (57% participation among eligible men) with newly diagnosed prostate cancer were enrolled from January 2011 through June 2013 in collaboration with the North Carolina Central Cancer Registry. Median time from diagnosis to enrollment was 5 weeks, and all men were enrolled with written informed consent prior to treatment. Final follow-up date for current analysis was September 9, 2015. Exposures Treatment with radical prostatectomy, external beam radiotherapy, brachytherapy, or active surveillance. Main Outcomes and Measures Quality of life using the validated instrument Prostate Cancer Symptom Indices was assessed at baseline (pretreatment) and 3, 12, and 24 months after treatment. The instrument contains 4 domains—sexual dysfunction, urinary obstruction and irritation, urinary incontinence, and bowel problems—each scored from 0 (no dysfunction) to 100 (maximum dysfunction). Propensity-weighted mean domain scores were compared between each treatment group vs active surveillance at each time point. Results Of 1141 enrolled men, 314 pursued active surveillance (27.5%), 469 radical prostatectomy (41.1%), 249 external beam radiotherapy (21.8%), and 109 brachytherapy (9.6%). After propensity weighting, median age was 66 to 67 years across groups, and 77% to 80% of participants were white. Across groups, propensity-weighted mean baseline scores were 41.8 to 46.4 for sexual dysfunction, 20.8 to 22.8 for urinary obstruction and irritation, 9.7 to 10.5 for urinary incontinence, and 5.7 to 6.1 for bowel problems. Compared with active surveillance, mean sexual dysfunction scores worsened by 3 months for patients who received radical prostatectomy (36.2 [95% CI, 30.4-42.0]), external beam radiotherapy (13.9 [95% CI, 6.7-21.2]), and brachytherapy (17.1 [95% CI, 7.8-26.6]). Compared with active surveillance at 3 months, worsened urinary incontinence was associated with radical prostatectomy (33.6 [95% CI, 27.8-39.2]); acute worsening of urinary obstruction and irritation with external beam radiotherapy (11.7 [95% CI, 8.7-14.8]) and brachytherapy (20.5 [95% CI, 15.1-25.9]); and worsened bowel symptoms with external beam radiotherapy (4.9 [95% CI, 2.4-7.4]). By 24 months, mean scores between treatment groups vs active surveillance were not significantly different in most domains

    Oncological outcomes of visibly complete transurethral resection prior to neoadjuvant chemotherapy for bladder cancer

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    ABSTRACT Purpose: To evaluate the potential oncologic benefit of a visibly complete transurethral resection of a bladder tumor (TURBT) prior to neoadjuvant chemotherapy (NAC) and radical cystectomy (RC). Materials and Methods: We identified patients who received NAC and RC between 2011-2021. Records were reviewed to assess TURBT completeness. The primary outcome was pathologic downstaging (<ypT2N0), with complete pathologic response (ypT0N0) and survival as secondary endpoints. Logistic regression and Cox proportional hazards models were utilized. Results: We identified 153 patients, including 116 (76%) with a complete TURBT. Sixty-four (42%) achieved <ypT2N0 and 43 (28%) achieved ypT0N0. When comparing those with and without a complete TURBT, there was no significant difference in the proportion with <ypT2N0 (43% vs 38%, P=0.57) or ypT0N0 (28% vs 27%, P=0.87). After median follow-up of 3.6 years (IQR 1.5-5.1), 86 patients died, 37 died from bladder cancer, and 61 had recurrence. We did not observe a statistically significant association of complete TURBT with cancer-specific or recurrence-free survival (p≄0.20), although the hazard of death from any cause was significantly higher among those with incomplete TURBT even after adjusting for ECOG and pathologic T stage, HR 1.77 (95% CI 1.04-3.00, P=.034). Conclusions: A visibly complete TURBT was not associated with pathologic downstaging, cancer-specific or recurrence-free survival following NAC and RC. These data do not support the need for repeat TURBT to achieve a visibly complete resection if NAC and RC are planned

    Targeted hepatitis C antibody testing interventions: a systematic review and meta-analysis

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    Testing for hepatitis C virus (HCV) infection may reduce the risk of liver-related morbidity, by facilitating earlier access to treatment and care. This review investigated the effectiveness of targeted testing interventions on HCV case detection, treatment uptake, and prevention of liver-related morbidity. A literature search identified studies published up to 2013 that compared a targeted HCV testing intervention (targeting individuals or groups at increased risk of HCV) with no targeted intervention, and results were synthesised using meta-analysis. Exposure to a targeted testing intervention, compared to no targeted intervention, was associated with increased cases detected [number of studies (n) = 14; pooled relative risk (RR) 1.7, 95 % CI 1.3, 2.2] and patients commencing therapy (n = 4; RR 3.3, 95 % CI 1.1, 10.0). Practitioner-based interventions increased test uptake and cases detected (n = 12; RR 3.5, 95 % CI 2.5, 4.8; and n = 10; RR 2.2, 95 % CI 1.4, 3.5, respectively), whereas media/information-based interventions were less effective (n = 4; RR 1.5, 95 % CI 0.7, 3.0; and n = 4; RR 1.3, 95 % CI 1.0, 1.6, respectively). This meta-analysis provides for the first time a quantitative assessment of targeted HCV testing interventions, demonstrating that these strategies were effective in diagnosing cases and increasing treatment uptake. Strategies involving practitioner-based interventions yielded the most favourable outcomes. It is recommended that testing should be targeted at and offered to individuals who are part of a population with high HCV prevalence, or who have a history of HCV risk behaviour

    An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

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    For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types

    Linking Changes in Epithelial Morphogenesis to Cancer Mutations Using Computational Modeling

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    Most tumors arise from epithelial tissues, such as mammary glands and lobules, and their initiation is associated with the disruption of a finely defined epithelial architecture. Progression from intraductal to invasive tumors is related to genetic mutations that occur at a subcellular level but manifest themselves as functional and morphological changes at the cellular and tissue scales, respectively. Elevated proliferation and loss of epithelial polarization are the two most noticeable changes in cell phenotypes during this process. As a result, many three-dimensional cultures of tumorigenic clones show highly aberrant morphologies when compared to regular epithelial monolayers enclosing the hollow lumen (acini). In order to shed light on phenotypic changes associated with tumor cells, we applied the bio-mechanical IBCell model of normal epithelial morphogenesis quantitatively matched to data acquired from the non-tumorigenic human mammary cell line, MCF10A. We then used a high-throughput simulation study to reveal how modifications in model parameters influence changes in the simulated architecture. Three parameters have been considered in our study, which define cell sensitivity to proliferative, apoptotic and cell-ECM adhesive cues. By mapping experimental morphologies of four MCF10A-derived cell lines carrying different oncogenic mutations onto the model parameter space, we identified changes in cellular processes potentially underlying structural modifications of these mutants. As a case study, we focused on MCF10A cells expressing an oncogenic mutant HER2-YVMA to quantitatively assess changes in cell doubling time, cell apoptotic rate, and cell sensitivity to ECM accumulation when compared to the parental non-tumorigenic cell line. By mapping in vitro mutant morphologies onto in silico ones we have generated a means of linking the morphological and molecular scales via computational modeling. Thus, IBCell in combination with 3D acini cultures can form a computational/experimental platform for suggesting the relationship between the histopathology of neoplastic lesions and their underlying molecular defects

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

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    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be ∌24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with ÎŽ<+34.5∘\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r∌27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

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    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
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