122 research outputs found
Integrated Spacecraft Autonomous Attitude Control (ISAAC)
The purpose of this project is to give undergraduate students an opportunity to design, manufacture, and maintain a mock spacecraft to be used as a testbed for autonomous control systems. The spacecraft is based on two previous models: the JX-01, an undergraduate built testbed, and the Asteroid Free Flyer led by NASA engineer and ERAU doctoral student, Michael Dupuis. This model includes cable improvements, Inertial Measurement Units (IMU), Light Detection and Ranging (LIDAR), and object-based state estimation to improve control stabilization. When completed, the hardware built for this project will provide undergraduates and researchers a platform with which they can test control algorithms and spacecraft component design. The results gathered from the project thus far is the building and design and controls experience between the team. After completion we will be able to obtain a properly modeled control algorithm and test it against multiple conditions. The final goal of the spacecraft is to provide the capabilities and perform experiments to test multiple methods to mitigate the effects of internal and external forces such as fuel sloshing, solar radiation, debris collision, and CG change
Integrated Spacecraft Autonomous Attitude Control (ISAAC)
The purpose of this project is to give undergraduate students an opportunity to design, manufacture, and maintain a mock spacecraft to be used as a testbed for autonomous control systems. The spacecraft is based on two previous models: the JX-01, an undergraduate built testbed, and the Asteroid Free Flyer led by NASA engineer and ERAU doctoral student, Michael Dupuis. This model includes cable improvements, Inertial Measurement Units (IMU), Light Detection and Ranging (LIDAR), and object-based state estimation to improve control stabilization. When completed, the hardware built for this project will provide undergraduates and researchers a platform with which they can test control algorithms and spacecraft component design. The results gathered from the project thus far is the building and design and controls experience between the team. After completion we will be able to obtain a properly modeled control algorithm and test it against multiple conditions. The final goal of the spacecraft is to provide the capabilities and perform experiments to test multiple methods to mitigate the effects of internal and external forces such as fuel sloshing, solar radiation, debris collision, and CG change
Understanding how perceptions of tobacco constituents and the FDA relate to effective and credible tobacco risk messaging: A national phone survey of U.S. adults, 2014–2015
As reported in the original paper [1], the Center for Regulatory
Research on Tobacco Communication conducted a
telephone survey in 2014–2015 with a national sample of
adults ages 18 and older living in the United States
(N = 5014). Poverty level was determined using the household
size and income reported by the respondents and
applying the federal poverty numbers available from the
U.S. Department of Health and Human Services in 2014.
A coding error was made during the data recoding process
such that 2.7% of respondents (n = 129) were incorrectly
classified as living above the poverty line. Below are
updated Tables 1, 2 and 4 presenting both the original and
corrected estimates. No substantive conclusions reported
in the paper were affected by this correction
Allochthonous and autochthonous contributions to carbon accumulation and carbon store in southeastern Australian coastal wetlands
Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study
Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised
The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy
Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations.
Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves.
Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p 90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score.
Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care
Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study
Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
Violence is rare in autism : when it does occur, is it sometimes extreme?
A small body of literature has suggested that, rather than being more likely to engage in offending or violent behaviour, individuals with autism spectrum disorder (ASD) may actually have an increased risk of being the victim rather than the perpetrator of violence (Sobsey et al., 1995). There is no evidence that people with ASD are more violent than those without ASD (Im, 2016). There is nevertheless a small subgroup of individuals with ASD who exhibit violent offending behaviours and our previous work has suggested that other factors, such as adverse childhood experiences, might be important in this subgroup (Allely et al., 2014). Fitzgerald (2015) highlights that school shootings and mass killings are not uncommonly carried out by individuals with neurodevelopmental disorders, with frequent evidence of warning indicators. The aim of the present review is to investigate this in more detail using the 73 mass shooting cases identified by Mother Jones (motherjones.com) in their database for potential ASD features. This exercise tentatively suggests evidence of ASD in six of 73 included cases (8%) which is ten times higher when compared to the prevalence of ASD found in the general population worldwide (motherjones.com). The 8% figure for individuals with ASD involved mass killings is a conservative estimate. In addition to the six cases which provide the 8% figure, there were 15 other cases with some indication of ASD. Crucially, ASD may influence, but does not cause, an individual to commit extreme violent acts such as a mass shooting episode
A checklist for assessing the methodological quality of concurrent tES-fMRI studies (ContES checklist): a consensus study and statement
Background: Low intensity transcranial electrical stimulation (tES), including alternating or direct current stimulation (tACS or tDCS), applies weak electrical stimulation to modulate the activity of brain circuits. Integration of tES with concurrent functional magnetic resonance imaging (fMRI) allows for the mapping of neural activity during neuromodulation, supporting causal studies of both brain function and tES effects. Methodological aspects of tES-fMRI studies underpin the results, and reporting them in appropriate detail is required for reproducibility and interpretability. Despite the growing number of published reports, there are no consensus-based checklists for disclosing methodological details of concurrent tES-fMRI studies. Objective: To develop a consensus-based checklist of reporting standards for concurrent tES-fMRI studies to support methodological rigor, transparency, and reproducibility (ContES Checklist). Methods: A two-phase Delphi consensus process was conducted by a steering committee (SC) of 13 members and 49 expert panelists (EP) through the International Network of the tES-fMRI (INTF) Consortium. The process began with a circulation of a preliminary checklist of essential items and additional recommendations, developed by the SC based on a systematic review of 57 concurrent tES-fMRI studies. Contributors were then invited to suggest revisions or additions to the initial checklist. After the revision phase, contributors rated the importance of the 17 essential items and 42 additional recommendations in the final checklist. The state of methodological transparency within the 57 reviewed concurrent tES-fMRI studies was then assessed using the checklist. Results: Experts refined the checklist through the revision and rating phases, leading to a checklist with three categories of essential items and additional recommendations: (1) technological factors, (2) safety and noise tests, and (3) methodological factors. The level of reporting of checklist items varied among the 57 concurrent tES-fMRI papers, ranging from 24% to 76%. On average, 53% of checklist items were reported in a given article. Conclusions: Use of the ContES checklist is expected to enhance the methodological reporting quality of future concurrent tES-fMRI studies, and increase methodological transparency and reproducibility
Habitat fragmentation leads to reduced pollinator visitation, fruit production and recruitment in urban mangrove forests
Mangrove forests worldwide undergo anthropogenic fragmentation that may threaten their existence, and yet there have been few tests of the effects of fragmentation on demographic processes critical for mangrove regeneration. Predicting the effects of habitat fragmentation on mangroves is problematic as pollinators may move more freely across water than terrestrial habitat, and propagules can be widely dispersed by water. Here, within each of two estuaries, we compared pollinator diversity and activity, reproductive effort and output, and rates of recruitment for sets of three large ( \u3e 1500 trees), medium (300-500) and small ( \u3c 50) stands. As predicted, most measures of reproductive activity and success were inversely related to stand size with large stands typically producing significantly more and larger fruit, and significantly more seedlings. Most strikingly, we found the effect of fragmentation on the abundance of pollinators (honeybees), the production and quality of fruit and the survival rate of seedlings to be similar, showing significant reduction of recruitment in small stands. This study provides the first rigorous evidence that recruitment of mangroves, like for many terrestrial plants, is negatively impacted by habitat fragmentation. From a management perspective, we argue that in the short term our data imply the importance of conserving the largest possible stands. However, additional work is needed to determine (1) the proportion of recruits within small stands that originate within large stands, (2) how seedling performance varies with fruit size and genotype, and (3) how seedling size and performance vary with the abundance and diversity of pollen
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