228 research outputs found

    Finding Subdwarf B stars using Python automation and TESS data

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    Subdwarf B (sdB) stars are extreme horizontal branch stars with high temperature and gravity. The most promising formation scenarios involve close binary star evolution with three different channels, (a) Common Envelope (CE) channel , which can produce short period (P = 0.1 – 10 d) sdB + white dwarf (WD) or main sequence (MS) binary systems, (b) Roche lobe overflow (RLOF) channel, which results in long period (450 \u3c P \u3c 1400 d) sdb + MS binary systems, and (c) white-dwarf merger channel, which can produce single sdB stars. Unlike other types of stars, sdB types have a myriad of data; however, there is lack of automation code in the RLOF channel due to long-term efforts. This Python program aims to aid these missing areas in sdB binary research by automating the pulsation timing process. This Python program has been proven to shorten the analysis time down to a couple of minutes and has been tested with the target TIC 273218137 (BPM 36430) for accuracy due to the known binary status of the target. This program will be able to decrease the amount of time needed to analyze data and increase the number of discoveries that are able to be made

    Open, Organized, and Onerous: Understanding and Recognizing the Labors of Open Science

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    In the face of high-profile cases of scientific fraud, there has been a renewed call among scholars to reconsider current best practices in academic publishing. Prominent in these discussions is a set of open science practices that ask scholars to “publish more” of their research—not in terms of manuscripts, but in terms of supplemental materials to the scientific enterprise. Through creating, curating, and publishing artifacts such as study materials (experimental stimuli, survey texts, etc.), datasets and analysis code, and other content, the scientific process is made more transparent for readers. However, such practices involve a substantial labor cost to researchers that is de facto invisible, as few institutions formally recognize the value in these practices, which can serve to implicitly disincentivize their adoption. This essay presents a brief review of open science practices (including their challenges and opportunities) and suggests ways in which administrators can incentivize these practices, as well as the local and global impacts of those incentives. Ultimately, administrators have the capacity to reward scholars for producing quality and impactful scholarship

    Coaching with self-determination in mind: Using theory to advance evidence-based coaching practice

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    The scholarly coaching literature has advanced considerably in the past decade. However, a review of the existing knowledge base suggests that coaching practice and research remains relatively uninformed by relevant psychological theory. In this paper it will be argued that Self-Determination Theory (SDT; Deci & Ryan, 1985) presents as a useful theoretical framework for coaching as it can help understand coaching practice at both macro and micro levels. The utility of SDT as a theoretical framework for coaching is explored, with particular attention given to the role that coaching would appear to play in the satisfaction of three basic psychological needs: autonomy, competence and relatedness. It is also argued that SDT provides a useful set of propositions that can guide empirical work and ground it in the firm foundations of a theoretically coherent, empirically valid account of human functioning and wellbeing. Suggestions are made for future directions in research informed by SDT

    Improvements in short-term forecasting of geomagnetic activity

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    We have improved our space weather forecasting algorithms to now predict Dst and AE in addition to Kp for up to 6 h of forecast times. These predictions can be accessed in real time at http://mms.rice. edu/realtime/forecast.html. In addition, in the event of an ongoing or imminent activity, e-mail “alerts” based on key discriminator levels have been going out to our subscribers since October 2003. The neural network–based algorithms utilize ACE data to generate full 1, 3, and 6 h ahead predictions of these indices from the Boyle index, an empirical approximation that estimates the Earth’s polar cap potential using solar wind parameters. Our models yield correlation coefficients of over 0.88, 0.86, and 0.83 for 1 h predictions of Kp, Dst, and AE, respectively, and 0.86, 0.84, and 0.80 when predicting the same but 3 h ahead. Our 6 h ahead predictions, however, have slightly higher uncertainties. Furthermore, the paper also tests other solar wind functions—the Newell driver, the Borovsky control function, and adding solar wind pressure term to the Boyle index—for their ability to predict geomagnetic activity

    Coordination by Cdc42 of actin, contractility, and adhesion for melanoblast movement in mouse skin

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    YesThe individual molecular pathways downstream of Cdc42, Rac, and Rho GTPases are well documented, but we know surprisingly little about how these pathways are coordinated when cells move in a complex environment in vivo. In the developing embryo, melanoblasts originating from the neural crest must traverse the dermis to reach the epidermis of the skin and hair follicles. We previously established that Rac1 signals via Scar/WAVE and Arp2/3 to effect pseudopod extension and migration of melanoblasts in skin. Here we show that RhoA is redundant in the melanocyte lineage but that Cdc42 coordinates multiple motility systems independent of Rac1. Similar to Rac1 knockouts, Cdc42 null mice displayed a severe loss of pigmentation, and melanoblasts showed cell-cycle progression, migration, and cytokinesis defects. However, unlike Rac1 knockouts, Cdc42 null melanoblasts were elongated and displayed large, bulky pseudopods with dynamic actin bursts. Despite assuming an elongated shape usually associated with fast mesenchymal motility, Cdc42 knockout melanoblasts migrated slowly and inefficiently in the epidermis, with nearly static pseudopods. Although much of the basic actin machinery was intact, Cdc42 null cells lacked the ability to polarize their Golgi and coordinate motility systems for efficient movement. Loss of Cdc42 de-coupled three main systems: actin assembly via the formin FMNL2 and Arp2/3, active myosin-II localization, and integrin-based adhesion dynamics.Cancer Research UK (to L.M.M. [A17196], R.H.I. [A19257], and S.W.G.T.) and NIH grants P01-GM103723 and P41-EB002025 (to K.M.H.). N.R.P. is supported by a Pancreatic Cancer Research Fund grant (to L.M.M.). Funding to Prof. Rottner by the Deutsche Forschungsgemeinschaft (grant RO2414/3-2)

    Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

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    Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

    Percutaneous coronary angioplasty versus coronary artery bypass grafting in treatment of unprotected left main stenosis (NOBLE) : a prospective, randomised, open-label, non-inferiority trial

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    Background Coronary artery bypass grafting (CABG) is the standard treatment for revascularisation in patients with left main coronary artery disease, but use of percutaneous coronary intervention (PCI) for this indication is increasing. We aimed to compare PCI and CABG for treatment of left main coronary artery disease. Methods In this prospective, randomised, open-label, non-inferiority trial, patients with left main coronary artery disease were enrolled in 36 centres in northern Europe and randomised 1: 1 to treatment with PCI or CABG. Eligible patients had stable angina pectoris, unstable angina pectoris, or non-ST-elevation myocardial infarction. Exclusion criteria were ST-elevation myocardial infarction within 24 h, being considered too high risk for CABG or PCI, or expected survival of less than 1 year. The primary endpoint was major adverse cardiac or cerebrovascular events (MACCE), a composite of all-cause mortality, non-procedural myocardial infarction, any repeat coronary revascularisation, and stroke. Non-inferiority of PCI to CABG required the lower end of the 95% CI not to exceed a hazard ratio (HR) of 1 . 35 after up to 5 years of follow-up. The intention-to-treat principle was used in the analysis if not specified otherwise. This trial is registered with ClinicalTrials.gov identifier, number NCT01496651. Findings Between Dec 9, 2008, and Jan 21, 2015, 1201 patients were randomly assigned, 598 to PCI and 603 to CABG, and 592 in each group entered analysis by intention to treat. Kaplan-Meier 5 year estimates of MACCE were 29% for PCI (121 events) and 19% for CABG (81 events), HR 1 . 48 (95% CI 1 . 11-1 . 96), exceeding the limit for non-inferiority, and CABG was significantly better than PCI (p=0 . 0066). As-treated estimates were 28% versus 19% (1 . 55, 1 . 18-2 . 04, p= 0 . 0015). Comparing PCI with CABG, 5 year estimates were 12% versus 9% (1 . 07, 0 . 67-1 . 72, p= 0 . 77) for all-cause mortality, 7% versus 2% (2 . 88, 1 . 40-5 . 90, p= 0 . 0040) for non-procedural myocardial infarction, 16% versus 10% (1 . 50, 1 . 04-2 . 17, p= 0 . 032) for any revascularisation, and 5% versus 2% (2 . 25, 0 . 93-5 . 48, p= 0 . 073) for stroke. Interpretation The findings of this study suggest that CABG might be better than PCI for treatment of left main stem coronary artery disease.Peer reviewe

    Convalescent human IgG, but not IgM, from COVID-19 survivors confers dose-dependent protection against SARS-CoV-2 replication and disease in hamsters

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    IntroductionAntibody therapeutic strategies have served an important role during the COVID-19 pandemic, even as their effectiveness has waned with the emergence of escape variants. Here we sought to determine the concentration of convalescent immunoglobulin required to protect against disease from SARS-CoV-2 in a Syrian golden hamster model.MethodsTotal IgG and IgM were isolated from plasma of SARS-CoV-2 convalescent donors. Dose titrations of IgG and IgM were infused into hamsters 1 day prior to challenge with SARS-CoV-2 Wuhan-1.ResultsThe IgM preparation was found to have ~25-fold greater neutralization potency than IgG. IgG infusion protected hamsters from disease in a dose-dependent manner, with detectable serum neutralizing titers correlating with protection. Despite a higher in vitro neutralizing potency, IgM failed to protect against disease when transferred into hamsters.DiscussionThis study adds to the growing body of literature that demonstrates neutralizing IgG antibodies are important for protection from SARS-CoV-2 disease, and confirms that polyclonal IgG in sera can be an effective preventative strategy if the neutralizing titers are sufficiently high. In the context of new variants, against which existing vaccines or monoclonal antibodies have reduced efficacy, sera from individuals who have recovered from infection with the emerging variant may potentially remain an efficacious tool
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