47 research outputs found
CLIMODE bobber data report : July 2005 - May 2009
This report summarizes direct observations of Eighteen Degree Water (EDW) subduction
and dispersal within the subtropical gyre of the North Atlantic Ocean. Forty acoustically-tracked
bobbing, profiling floats (“bobbers”) were deployed to study the formation and
dispersal of EDW in the western North Atlantic. The unique bobber dataset described
herein provides insight into the evolution of EDW by means of direct, eddy-resolving
measurement of EDW Lagrangian dispersal pathways and stratification. Bobbers are
modified Autonomous Profiling Explorer (APEX) profiling floats which actively servo
their buoyancy control mechanism to follow a particular isothermal surface. The
CLIVAR Mode Water Dynamics Experiment (CLIMODE) bobbers tracked the 18.5°C
temperature surface for 3 days, then bobbed quickly between the 17°C and 19°C
isotherms. This cycle was repeated for one month, after which each bobber profiled to
1000 m before ascending to the surface to transmit data. The resulting dataset (37/40
tracked bobbers; more than half still profiling as of January 2010) yields well-resolved
trajectories, unprecedented velocity statistics in the core of the subducting and spreading
EDW, and detailed information about the Lagrangian evolution of EDW thickness and
vertical structure. This report provides an overview of the experimental procedure
employed and summarizes the initial processing of the bobber dataset.Funding was provided by the National Science Foundation under Grant No. OCE-0424492
The relationship between external knee moments and muscle co-activation in subjects with medial knee osteoarthritis
Purpose: External knee moments are reliable to measure knee load but it does not take into
account muscle activity. Considering that muscle co-activation increases compressive forces
at the knee joint, identifying relationships between muscle co-activations and knee joint
load would complement the investigation of the knee loading in subjects with knee
osteoarthritis. The purpose of this study was to identify relationships between muscle coactivation
and external knee moments during walking in subjects with medial knee
osteoarthritis. Methods: 19 controls (11 males, aged 56.6 ±5, and BMI 25.2 ± 3.3) and 25
subjects with medial knee osteoarthritis (12 males, aged 57.3 ± 5.3, and BMI 28.2 ± 4) were
included in this study. Knee adduction and flexion moments, and co-activation (ratios and
sums of quadriceps, hamstring, and gastrocnemius) were assessed during walking and
compared between groups. The relationship between knee moments and co-activation was
investigated in both groups. Findings: subjects with knee osteoarthritis presented a
moderate and strong correlation between co-activation (ratios and sums) and knee
moments. Interpretation: Muscle co-activation should be used to measure the contribution
of quadriceps, hamstring, and gastrocnemius on knee loading. This information would
cooperate to develop a more comprehensive approach of knee loading in this population
Assessing ADHD symptoms in children and adults:Evaluating the role of objective measures
Background:
Diagnostic guidelines recommend using a variety of methods to assess and diagnose ADHD. Applying subjective measures always incorporates risks such as informant biases or large differences between ratings obtained from diverse sources. Furthermore, it has been demonstrated that ratings and tests seem to assess somewhat different constructs. The use of objective measures might thus yield valuable information for diagnosing ADHD. This study aims at evaluating the role of objective measures when trying to distinguish between individuals with ADHD and controls. Our sample consisted of children (n = 60) and adults (n = 76) diagnosed with ADHD and matched controls who completed self- and observer ratings as well as objective tasks. Diagnosis was primarily based on clinical interviews. A popular pattern recognition approach, support vector machines, was used to predict the diagnosis.
Results:
We observed relatively high accuracy of 79% (adults) and 78% (children) applying solely objective measures. Predicting an ADHD diagnosis using both subjective and objective measures exceeded the accuracy of objective measures for both adults (89.5%) and children (86.7%), with the subjective variables proving to be the most relevant.
Conclusions:
We argue that objective measures are more robust against rater bias and errors inherent in subjective measures and may be more replicable. Considering the high accuracy of objective measures only, we found in our study, we think that they should be incorporated in diagnostic procedures for assessing ADHD
Implementation of Dynamical Nucleation Theory Effective Fragment Potentials Method for Modeling Aerosol Chemistry
Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK.
BACKGROUND: A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. METHODS: This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. FINDINGS: Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0-75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4-97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8-80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3-4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. INTERPRETATION: ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials. FUNDING: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, Lemann Foundation, Rede D'Or, Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca
Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK
Background
A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials.
Methods
This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674.
Findings
Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0–75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4–97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8–80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3–4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation.
Interpretation
ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Pleiotropic Effects of Natural Genetic Variation in Drosophila Melanogaster on Fitness
Pleiotropic genes can influence the course of evolution by producing correlated responses to selection and potentially hindering adaptive evolution if alternative alleles have antagonistic effects on fitness traits. Little is known about the pleiotropic effects of natural variation in any gene on fitness and the selective agents acting on this variation. In this thesis, I examined the pleiotropic effects of natural variation in the Dopa decarboxylase (Ddc) gene of Drosophila melanogaster. I show that natural Ddc polymorphism associated with life span variation has pleiotropic effects on larval defenses against parasitoid wasps, larval foraging behavior, and larval feeding rates. I measured these traits because Ddc catalyzes the production of two neurotransmitters, dopamine and serotonin, which have known effects on behavior and immunity in invertebrates and vertebrates. Homozygote and heterozygote effects of two Ddc alleles with opposing life spans were measured for each larval trait. Larvae homozygous or heterozygous for the long-lived Ddc allele had a better immune response against the parasitoid, Aphaereta sp., but were parasitized more by Leptopilina boulardi than larvae homozygous for the short-lived Ddc allele. Similar differences in parasitism avoidance were found when larvae with different Ddc genotypes were exposed to natural rates of parasitism by L. boulardi in the field, confirming the ecological relevance of the Ddc polymorphism. Larvae with the long-lived Ddc allele moved shorter distances while foraging and fed slower than larvae homozygous for the short-lived Ddc allele, which supports a known trade off between immune resistance and larval competitive ability. Heterozygous larvae have higher levels of dopamine than larvae homozygous for the short-lived Ddc allele suggesting thatDdc polymorphism has functional consequences for the observed phenotypic variation. I also conducted a multi-year field study (2004-2006) to investigate the interrelationships between Drosophila and its parasitoids in two natural populations in the Baltimore, MD area, which allowed documentation of ecological variables that may select for differences in larval fitness traits influenced by Ddc
Teacher Readiness to Implement Technology Innovations
This paper is a report of a cross sectional survey study of teacher readiness to implement technology initiatives in their schools. The sample of participants in the study has been comparable, with respect to gender, to national data on teachers in the United States. The technology initiatives reported are reflective of current market trends in the United States. Teachers\u27 involvement in the planning of a technology initiative and their participation in professional development for that initiative were investigated with respect to their beliefs of feasibility, buy-in, and staff support for the initiative. The findings indicate that teachers who were involved in the planning of the initiative had more positive beliefs of the feasibility, buy-in, and staff support about the initiative. Training, either completed or plans for future training, enhanced teacher beliefs regarding staff support for the initiatives