48 research outputs found

    Uniform approximation of barrier penetration in phase space

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    A method to approximate transmission probabilities for a nonseparable multidimensional barrier is applied to a waveguide model. The method uses complex barrier-crossing orbits to represent reaction probabilities in phase space and is uniform in the sense that it applies at and above a threshold energy at which classical reaction switches on. Above this threshold the geometry of the classically reacting region of phase space is clearly reflected in the quantum representation. Two versions of the approximation are applied. A harmonic version which uses dynamics linearised around an instanton orbit is valid only near threshold but is easy to use. A more accurate and more widely applicable version using nonlinear dynamics is also described

    Taguchi Loss Function for Varus/Valgus Alignment in Total Knee Arthroplasty

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    Methods of designing equipment to improve quality have been developed by Taguchi. A key feature of these methods is the development of loss function, which quantifies the financial cost (loss) resulting from deviations from target dimensions. Total knee arthroplasties can fail due to prosthetic component malalignment. A Taguchi loss function for varus/valgus alignment of the prosthesis and revision rates was developed. Six studies were identified from a comprehensive literature search. Varus and extreme valgus alignments correlated with an increased percentage of prosthetic failure. A loss function of L( y) = 326.80y2,whereywasdeviationfromidealvarus/valgusangle,wasdetermined.TheexpectedlossfunctionwasEL=326.80y2 , where y was deviation from ideal varus/valgus angle, was determined. The expected loss function was EL=326.80y¯2+s2 , where y¯ was the mean deviance from the ideal varus/valgus angle and s2 was the variance in varus/valgus angle. This loss function was used to estimate the cost savings of using computer-assisted surgical navigation in total knee arthroplasty (TKA). The average savings of a navigated TKA versus a conventional TKA, based on the expected loss equation derived from the Taguchi loss function, was $2,304 per knee. The expected loss function derived here can serve as a tool for biomedical engineers seeking to use Taguchi quality engineering methods in designing orthopaedic devices

    Fruit crops: a summary of research, 1998

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    Pesticide deposition in orchards: effects of pesticide type, tree canopy, timing, cultivar, and leaf type / Franklin R. Hall, Jane A. Cooper, and David C. Ferree -- The influence of a synthetic foraging attractant, Bee-Scent™, on the number of honey bees visiting apple blossoms and on subsequent fruit production / James E. Tew and David C. Ferree -- The reliability of three traps vs. a single trap for determining population levels of codling moth in commercial northern Ohio apple orchards / Ted W. Gastier -- Evaluation of an empirical model for predicting sooty blotch and flyspeck of apples in Ohio / Michael A. Ellis, Laurence V. Madden, and L. Lee Wilson -- Influence of pesticides and water stress on photosynthesis and transpiration of apple / David C. Ferree, Franklin R. Hall, Charles R. Krause, Bruce R. Roberts, and Ross D. Brazee -- Influence of temporary bending and heading on branch development and flowering of vigorous young apple trees / David C. Ferree and John C. Schmid -- The effect of apple fruit bruising on total returns / Richard C. Funt, Ewen A. Cameron, and Nigel H. Banks -- Yield, berry quality, and economics of mechanical berry harvest in Ohio / Richard C. Funt, Thomas E. Wall, and Joseph C. Scheerens -- Monitoring flower thrips activities in strawberry fields at two Ohio locations / Roger N. Williams, M. Sean Ellis, Dan S. Fickle, and Carl M. Pelland -- Cluster thinning effects on fruit weight, juice quality, and fruit skin characteristics in 'Reliance' grapes / Yu Gao and Garth A. Cahoon -- Effects of various fungicide programs on powdery mildew control, percent berry sugar, yield, and vine vigor of 'Concord' grapes in Ohio / Michael A. Ellis, Laurence V. Madden, L. Lee Wilson, and Gregory R. Johns -- Influence of growth regulators, cropping, and number on replacement trunks of winter-injured 'Vidal Blanc' grapes / David C. Ferree, David M. Scurlock, and Rick Evans -- Effect of new herbicides on tissue-cultured black raspberry plants / Richard C. Funt, Thomas E. Wall, and B. Dale Stokes -- Investigating the relationship between vine vigor and berry set of field-grown 'Seyval Blanc' grapevines / Steven J. McArtney and David C. Ferree -- Summary of Ohio Fruit Growers Society apple cider competition, 1993-1997 / Winston Bash and Diane Mille

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Biomass production of herbaceous energy crops in the United States: field trial results and yield potential maps from the multiyear regional feedstock partnership

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    Current knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small-scale and short-term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform across multiple locations and years, the U.S. Department of Energy (US DOE)/Sun Grant Initiative Regional Feedstock Partnership was initiated in 2008. The objectives of the Feedstock Partnership were to (1) provide a wide range of information for feedstock selection (species choice) and management practice options for a variety of regions and (2) develop national maps of potential feedstock yield for each of the herbaceous species evaluated. The Feedstock Partnership expands our previous understanding of the bioenergy potential of switchgrass, Miscanthus, sorghum, energycane, and prairie mixtures on Conservation Reserve Program land by conducting long-term, replicated trials of each species at diverse environments in the U.S. Trials were initiated between 2008 and 2010 and completed between 2012 and 2015 depending on species. Field-scale plots were utilized for switchgrass and Conservation Reserve Program trials to use traditional agricultural machinery. This is important as we know that the smaller scale studies often overestimated yield potential of some of these species. Insufficient vegetative propagules of energycane and Miscanthus prohibited farm-scale trials of these species. The Feedstock Partnership studies also confirmed that environmental differences across years and across sites had a large impact on biomass production. Nitrogen application had variable effects across feedstocks, but some nitrogen fertilizer generally had a positive effect. National yield potential maps were developed using PRISM-ELM for each species in the Feedstock Partnership. This manuscript, with the accompanying supplemental data, will be useful in making decisions about feedstock selection as well as agronomic practices across a wide region of the country

    Initial Assessment, Surveillance, and Management of Blood Pressure in Patients Receiving Vascular Endothelial Growth Factor Signaling Pathway Inhibitors

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    Hypertension is a mechanism-based toxic effect of drugs that inhibit the vascular endothelial growth factor signaling pathway (VSP). Substantial evidence exists for managing hypertension as a chronic condition, but there are few prospectively collected data on managing acute hypertension caused by VSP inhibitors. The Investigational Drug Steering Committee of the National Cancer Institute convened an interdisciplinary cardiovascular toxicities expert panel to evaluate this problem, to make recommendations to the Cancer Therapy Evaluation Program on further study, and to structure an approach for safe management by treating physicians. The panel reviewed: the published literature on blood pressure (BP), hypertension, and specific VSP inhibitors; abstracts from major meetings; shared experience with the development of VSP inhibitors; and established principles of hypertension care. The panel generated a consensus report including the recommendations on clinical concerns summarized here. To support the greatest possible number of patients to receive VSP inhibitors safely and effectively, the panel had four recommendations: 1) conduct and document a formal risk assessment for potential cardiovascular complications, 2) recognize that preexisting hypertension will be common in cancer patients and should be identified and addressed before initiation of VSP inhibitor therapy, 3) actively monitor BP throughout treatment with more frequent assessments during the first cycle of treatment, and 4) manage BP with a goal of less than 140/90 mmHg for most patients (and to lower, prespecified goals in patients with specific preexisting cardiovascular risk factors). Proper agent selection, dosing, and scheduling of follow-up should enable maintaining VSP inhibition while avoiding the complications associated with excessive or prolonged elevation in BP

    Loss of Mitogen-Activated Protein Kinase Kinase Kinase 4 (MAP3K4) Reveals a Requirement for MAPK Signalling in Mouse Sex Determination

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    The boygirl (byg) mouse mutant reveals that MAP3K4-mediated signaling is necessary for normal SRY expression and testis specification in the developing mouse gonad

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

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    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

    A higher effort-based paradigm in physical activity and exercise for public health: making the case for a greater emphasis on resistance training

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    It is well known that physical activity and exercise is associated with a lower risk of a range of morbidities and all-cause mortality. Further, it appears that risk reductions are greater when physical activity and/or exercise is performed at a higher intensity of effort. Why this may be the case is perhaps explained by the accumulating evidence linking physical fitness and performance outcomes (e.g. cardiorespiratory fitness, strength, and muscle mass) also to morbidity and mortality risk. Current guidelines about the performance of moderate/vigorous physical activity using aerobic exercise modes focuses upon the accumulation of a minimum volume of physical activity and/or exercise, and have thus far produced disappointing outcomes. As such there has been increased interest in the use of higher effort physical activity and exercise as being potentially more efficacious. Though there is currently debate as to the effectiveness of public health prescription based around higher effort physical activity and exercise, most discussion around this has focused upon modes considered to be traditionally ‘aerobic’ (e.g. running, cycling, rowing, swimming etc.). A mode customarily performed to a relatively high intensity of effort that we believe has been overlooked is resistance training. Current guidelines do include recommendations to engage in ‘muscle strengthening activities’ though there has been very little emphasis upon these modes in either research or public health effort. As such the purpose of this debate article is to discuss the emerging higher effort paradigm in physical activity and exercise for public health and to make a case for why there should be a greater emphasis placed upon resistance training as a mode in this paradigm shift
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