123 research outputs found
Development Of a Control System For a 2D Biped Walking Robotic Testbed
Due to the great potential promise of bipedal walking robots, it was determined that the Jaywalker, a first generation bipedal walking testbed, should be designed and built as a platform for the study of bipedal walking over rough terrain and as a testbed for the research and development of the components necessary to develop a bipedal walking robot and for use in research beneficial to humanity that the testbed could facilitate. The Jaywalker adopts an approach of attempting to integrate the best of the ZMP bipedal walking robots characteristics with the best characteristics of the dynamic walkers and the basis for a control system capable of handling the distributed multiple inputs and multiple outputs necessary for an advanced bipedal walking robotic in a modular and easily updatable way
Independent Review Support for Phoenix Mars Mission Robotic Arm Brush Motor Failure
The Phoenix Project requested the NASA Engineering and Safety Center (NESC) perform an independent peer review of the Robotic Arm (RA) Direct Current (DC) motor brush anomalies that originated during the Mars Exploration Rover (MER) Project and recurred during the Phoenix Project. The request was to evaluate the Phoenix Project investigation efforts and provide an independent risk assessment. This includes a recommendation for additional work and assessment of the flight worthiness of the RA DC motors. Based on the investigation and findings contained within this report, the IRT concurs with the risk assessment Failure Cause / Corrective Action (FC/CA) by the project, "Failure Effect Rating "3"; Major Degradation or Total Loss of Function, Failure Cause/Corrective Action Rating Currently "4"; Unknown Cause, Uncertainty in Corrective Action.
Alliance Foundation Trial 09: A randomized, multicenter, phase 2 trial evaluating two sequences of pembrolizumab and standard platinum-based chemotherapy in patients with metastatic NSCLC
INTRODUCTION: The sequence of chemotherapy and pembrolizumab may affect antitumor immune response and efficacy of immunotherapy.
METHODS: This multicenter, randomized, phase 2 trial was designed to evaluate the efficacy of two sequences of chemotherapy and pembrolizumab in patients with stage 4 NSCLC. Both arms were considered investigational, and the study used a pick a winner design. The primary end point was objective response rate by independent radiologic review after eight cycles (24 wk). Patients were randomized 1:1 to arm A (chemotherapy for four cycles followed by pembrolizumab for four cycles) or arm B (pembrolizumab for four cycles followed by chemotherapy for four cycles). Patients in both arms without disease progression after the initial eight cycles continued pembrolizumab until disease progression, unacceptable toxicity, or a maximum of 2 years.
RESULTS: From March 2016 to July 2018, a total of 90 eligible patients were randomized (43 patients to arm A and 47 patients to arm B). The objective response rate at 24 weeks in arms A and B was 39.5 % (95 % confidence interval [CI]: 24.9%-54.1 %) and 40.4 % (95 % CI: 26.4%-54.5 %), respectively (
CONCLUSIONS: Additional evaluation of either sequence in a phase 3 trial is not warranted
Implementation of the Combined--Nonlinear Condensation Transformation
We discuss several applications of the recently proposed combined
nonlinear-condensation transformation (CNCT) for the evaluation of slowly
convergent, nonalternating series. These include certain statistical
distributions which are of importance in linguistics, statistical-mechanics
theory, and biophysics (statistical analysis of DNA sequences). We also discuss
applications of the transformation in experimental mathematics, and we briefly
expand on further applications in theoretical physics. Finally, we discuss a
related Mathematica program for the computation of Lerch's transcendent.Comment: 23 pages, 1 table, 1 figure (Comput. Phys. Commun., in press
A mixed-methods approach to understanding water use and water infrastructure in a schistosomiasis-endemic community: case study of Asamama, Ghana
Is local review of positron emission tomography scans sufficient in diffuse large B-cell lymphoma clinical trials? A CALGB 50303 analysis
BACKGROUND: Quantitative methods of Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) interpretation, including the percent change in FDG uptake from baseline (ΔSUV), are under investigation in lymphoma to overcome challenges associated with visual scoring systems (VSS) such as the Deauville 5-point scale (5-PS).
METHODS: In CALGB 50303, patients with DLBCL received frontline R-CHOP or DA-EPOCH-R, and although there were no significant associations between interim PET responses assessed centrally after cycle 2 (iPET) using 5-PS with progression-free survival (PFS) or overall survival (OS), there were significant associations between central determinations of iPET ∆SUV with PFS/OS. In this patient cohort, we retrospectively compared local vs central iPET readings and evaluated associations between local imaging data and survival outcomes.
RESULTS: Agreement between local and central review was moderate (kappa = 0.53) for VSS and high (kappa = 0.81) for ∆SUV categories (\u3c66% vs. ≥66%). ∆SUV ≥66% at iPET was significantly associated with PFS (p = 0.03) and OS (p = 0.002), but VSS was not. Associations with PFS/OS when applying local review vs central review were comparable.
CONCLUSIONS: These data suggest that local PET interpretation for response determination may be acceptable in clinical trials. Our findings also highlight limitations of VSS and call for incorporation of more objective measures of response assessment in clinical trials
Association between footwear use and neglected tropical diseases: a systematic review and meta-analysis
BACKGROUND
The control of neglected tropical diseases (NTDs) has primarily focused on preventive chemotherapy and case management. Less attention has been placed on the role of ensuring access to adequate water, sanitation, and hygiene and personal preventive measures in reducing exposure to infection. Our aim was to assess whether footwear use was associated with a lower risk of selected NTDs.
METHODOLOGY
We conducted a systematic review and meta-analysis to assess the association between footwear use and infection or disease for those NTDs for which the route of transmission or occurrence may be through the feet. We included Buruli ulcer, cutaneous larva migrans (CLM), leptospirosis, mycetoma, myiasis, podoconiosis, snakebite, tungiasis, and soil-transmitted helminth (STH) infections, particularly hookworm infection and strongyloidiasis. We searched Medline, Embase, Cochrane, Web of Science, CINAHL Plus, and Popline databases, contacted experts, and hand-searched reference lists for eligible studies. The search was conducted in English without language, publication status, or date restrictions up to January 2014. Studies were eligible for inclusion if they reported a measure of the association between footwear use and the risk of each NTD. Publication bias was assessed using funnel plots. Descriptive study characteristics and methodological quality of the included studies were summarized. For each study outcome, both outcome and exposure data were abstracted and crude and adjusted effect estimates presented. Individual and summary odds ratio (OR) estimates and corresponding 95% confidence intervals (CIs) were calculated as a measure of intervention effect, using random effects meta-analyses.
PRINCIPAL FINDINGS
Among the 427 studies screened, 53 met our inclusion criteria. Footwear use was significantly associated with a lower odds of infection of Buruli ulcer (OR=0.15; 95% CI: 0.08-0.29), CLM (OR=0.24; 95% CI: 0.06-0.96), tungiasis (OR=0.42; 95% CI: 0.26-0.70), hookworm infection (OR=0.48; 95% CI: 0.37-0.61), any STH infection (OR=0.57; 95% CI: 0.39-0.84), strongyloidiasis (OR=0.56; 95% CI: 0.38-0.83), and leptospirosis (OR=0.59; 95% CI: 0.37-0.94). No significant association between footwear use and podoconiosis (OR=0.63; 95% CI: 0.38-1.05) was found and no data were available for mycetoma, myiasis, and snakebite. The main limitations were evidence of heterogeneity and poor study quality inherent to the observational studies included.
CONCLUSIONS/SIGNIFICANCE
Our results show that footwear use was associated with a lower odds of several different NTDs. Access to footwear should be prioritized alongside existing NTD interventions to ensure a lasting reduction of multiple NTDs and to accelerate their control and elimination.
PROTOCOL REGISTRATION
PROSPERO International prospective register of systematic reviews CRD42012003338
Future vision for the quality assurance of oncology clinical trials
The National Cancer Institute clinical cooperative groups have been instrumental over the past 50 years in developing clinical trials and evidence-based process improvements for clinical oncology patient care. The cooperative groups are undergoing a transformation process as we further integrate molecular biology into personalized patient care and move to incorporate international partners in clinical trials. To support this vision, data acquisition and data management informatics tools must become both nimble and robust to support transformational research at an enterprise level. Information, including imaging, pathology, molecular biology, radiation oncology, surgery, systemic therapy, and patient outcome data needs to be integrated into the clinical trial charter using adaptive clinical trial mechanisms for design of the trial. This information needs to be made available to investigators using digital processes for real-time data analysis. Future clinical trials will need to be designed and completed in a timely manner facilitated by nimble informatics processes for data management. This paper discusses both past experience and future vision for clinical trials as we move to develop data management and quality assurance processes to meet the needs of the modern trial
Patterns and Risk Factors of Helminthiasis and Anemia in a Rural and a Peri-urban Community in Zanzibar, in the Context of Helminth Control Programs
In many parts of the developing world, parasitic worms and anemia are of considerable public health and economic importance. We studied the patterns and risk factors of parasitic worm infections in a rural and a peri-urban community on Zanzibar Island, Tanzania, in the context of national deworming programs. We invited 658 individuals aged between 5 and 100 years and examined their stool and urine for the presence of parasitic worm eggs. Additionally, we obtained a finger-prick blood sample to estimate the level of anemia and to assess for specific immune reactions against parasitic worm infections. We found that, despite large-scale deworming efforts in Zanzibar over the past 15 years, three-quarter of the rural participants and half of the peri-urban residents were infected with parasitic worms. Every second participant was anemic. Risk factors for a parasitic worm infection were age, sex, consumption of raw vegetables or salad, recent travel history, and socio-economic status. For a sustainable control of parasitic worm infections and prevention of anemia, access to safe and efficacious drugs, complemented with health education and improvements in water supply and adequate sanitation are necessary
Adult population as potential reservoir of NTD infections in rural villages of Kwale district, Coastal Kenya: implications for preventive chemotherapy interventions policy
<p>Abstract</p> <p>Background</p> <p>Neglected tropical diseases (NTDs) are major public health problems in developing countries where they contribute to suffering of populations living in poor settings. As part of a research project started in September 2009 in Kwale district, Coast Region, Kenya, a baseline cross-sectional survey was conducted in 5 rural villages to provide information on the status of NTDs, including urinary schistosomiasis, soil-transmitted helminthiasis (STH), and lymphatic filariasis. This paper presents the results of a parasitological investigation among adults in the study villages.</p> <p>Methods</p> <p>A total of 599 adults in the 5 study villages were tested for NTD infections in urine, stool and blood. The presence of <it>Schistosoma haematobium </it>infection was determined by the urine filtration method. The presence of STH in stool was determined by Kato-Katz method while filarial antigenaemia was determined using immunochromatographic (ICT) test.</p> <p>Results</p> <p>The study revealed high prevalence of hookworm (41.7%) and schistosomiasis (18.2%) infections among adults in the study villages. Of the 599 individuals examined, 50.1% had one or more helminthic infections. There was low level of polyparasitism with helminthic NTDs in the study population with 9.5% and 1.7% of the participants having two and three infections, respectively.</p> <p>Conclusions</p> <p>In the current study, hookworm and schistosomiasis infections were identified as important infections among adults living in areas of high endemicity for these infections. Thus, if this section of the population is left untreated it may remain an important potential reservoir and a source of re-infection for school-age children treated in school deworming programmes. Therefore, there is a need to design novel strategies for preventive chemotherapy interventions that could allow inclusion of adults in an effort to reduce force of infection in high endemic communities.</p
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