3,108 research outputs found

    Chemiluminescent Tags for Tracking Insect Movement in Darkness: Application to Moth Photo-Orientation

    Get PDF
    The flight tracks of Manduca sexta (Lepidoptera: Sphingidae) flying toward a 5 watt incandescent light bulb were recorded under low light conditions with the aid of a camera-mounted photomultiplier and a glowing marker technique. Small felt pads bearing a chemiluminescent (glowi ma­erial, Cyalume®, were affixed to the abdomens of free-flying moths. insects orienting to a dim incandescent bulb were easily visible to the naked eye and were clearly captured on videotape. On their initial approach to the light source, M. sexta were found to orient at a mean angle of -0.220 ± 2.70 (mean ± SEM). The speed of the initial approach flight (OA ± 0.03 m/s) was significantly faster than the speed immediately after passing the light (0.29 ± 0.02 m/s; t =6.4, PM. sexta initially fly approximately at a light source and only after passing it, do they engage in circular flight around the source. M. sexta flight to lights does not entirely match any paths predicted by several light orientation mechanisms, including the commonly invoked light compass theory

    Electrical switching in a magnetically intercalated transition metal dichalcogenide.

    Get PDF
    Advances in controlling the correlated behaviour of transition metal dichalcogenides have opened a new frontier of many-body physics in two dimensions. A field where these materials have yet to make a deep impact is antiferromagnetic spintronics-a relatively new research direction promising technologies with fast switching times, insensitivity to magnetic perturbations and reduced cross-talk1-3. Here, we present measurements on the intercalated transition metal dichalcogenide Fe1/3NbS2 that exhibits antiferromagnetic ordering below 42 K (refs. 4,5). We find that remarkably low current densities of the order of 104 A cm-2 can reorient the magnetic order, which can be detected through changes in the sample resistance, demonstrating its use as an electronically accessible antiferromagnetic switch. Fe1/3NbS2 is part of a larger family of magnetically intercalated transition metal dichalcogenides, some of which may exhibit switching at room temperature, forming a platform from which to build tuneable antiferromagnetic spintronic devices6,7

    Estimating Global Injuries Morbidity and Mortality: Methods and Data Used in the Global Burden of Disease 2017 Study

    Get PDF
    Background While there is a long history of measuring death and disability from injuries, modern research methods must account for the wide spectrum of disability that can occur in an injury, and must provide estimates with sufficient demographic, geographical and temporal detail to be useful for policy makers. The Global Burden of Disease (GBD) 2017 study used methods to provide highly detailed estimates of global injury burden that meet these criteria. Methods In this study, we report and discuss the methods used in GBD 2017 for injury morbidity and mortality burden estimation. In summary, these methods included estimating cause-specific mortality for every cause of injury, and then estimating incidence for every cause of injury. Non-fatal disability for each cause is then calculated based on the probabilities of suffering from different types of bodily injury experienced. Results GBD 2017 produced morbidity and mortality estimates for 38 causes of injury. Estimates were produced in terms of incidence, prevalence, years lived with disability, cause-specific mortality, years of life lost and disability-adjusted life-years for a 28-year period for 22 age groups, 195 countries and both sexes. Conclusions GBD 2017 demonstrated a complex and sophisticated series of analytical steps using the largest known database of morbidity and mortality data on injuries. GBD 2017 results should be used to help inform injury prevention policy making and resource allocation. We also identify important avenues for improving injury burden estimation in the future

    Validating Estimates of Prevalence of Non-Communicable Diseases Based on Household Surveys: The Symptomatic Diagnosis Study

    Get PDF
    Easy-to-collect epidemiological information is critical for the more accurate estimation of the prevalence and burden of different non-communicable diseases around the world. Current measurement is restricted by limitations in existing measurement systems in the developing world and the lack of biometry tests for non-communicable diseases. Diagnosis based on self-reported signs and symptoms (“Symptomatic Diagnosis,” or SD) analyzed with computer-based algorithms may be a promising method for collecting timely and reliable information on non-communicable disease prevalence. The objective of this study was to develop and assess the performance of a symptom-based questionnaire to estimate prevalence of non-communicable diseases in low-resource areas

    Perception of carbohydrate availability augments high-intensity intermittent exercise capacity under sleep-low train low conditions

    Get PDF
    The authors tested the hypothesis that perception of carbohydrate (CHO) availability augments exercise capacity in conditions of reduced CHO availability. Nine males completed a sleep-low train model comprising evening glycogen-depleting cycling followed by an exhaustive cycling protocol the next morning in the fasted state (30 min steady state at 95% lactate threshold followed by 1-min intervals at 80% peak power output until exhaustion). After the evening depletion protocol and prior to sleeping, subjects consumed (a) a known CHO intake of 6 g/kg body mass (TRAIN HIGH) or (b) a perceived comparable CHO intake but 0 g/kg body mass (PERCEPTION) or a known train-low condition of 0 g/kg body mass (TRAIN LOW). The TRAIN HIGH and PERCEPTION trials were conducted double blind. During steady state, average blood glucose and CHO oxidation were significantly higher in TRAIN HIGH (4.01 ± 0.56 mmol/L; 2.17 ± 0.70 g/min) versus both PERCEPTION (3.30 ± 0.57 mmol/L; 1.69 ± 0.64 g/min, p < .05) and TRAIN LOW (3.41 ± 0.74 mmol/L; 1.61 ± 0.59 g/min, p < .05). Exercise capacity was significantly different between all pairwise comparisons (p < .05), where TRAIN LOW (8 ± 8 min) < PERCEPTION (12 ± 6 min) < TRAIN HIGH (22 ± 9 min). Data demonstrate that perception of CHO availability augments high-intensity intermittent exercise capacity under sleep-low, train-low conditions, though this perception does not restore exercise capacity to that of CHO consumption. Such data have methodological implications for future research designs and may also have practical applications for athletes who deliberately practice elements of training in CHO-restricted states

    Global injury morbidity and mortality from 1990 to 2017: results from the Global Burden of Disease Study 2017

    Get PDF
    Background: Past research in population health trends has shown that injuries form a substantial burden of population health loss. Regular updates to injury burden assessments are critical. We report Global Burden of Disease (GBD) 2017 Study estimates on morbidity and mortality for all injuries. Methods: We reviewed results for injuries from the GBD 2017 study. GBD 2017 measured injury-specific mortality and years of life lost (YLLs) using the Cause of Death Ensemble model. To measure non-fatal injuries, GBD 2017 modelled injury-specific incidence and converted this to prevalence and years lived with disability (YLDs). YLLs and YLDs were summed to calculate disability-adjusted life years (DALYs). Findings: In 1990, there were 4 260 493 (4 085 700 to 4 396 138) injury deaths, which increased to 4 484 722 (4 332 010 to 4 585 554) deaths in 2017, while age-standardised mortality decreased from 1079 (1073 to 1086) to 738 (730 to 745) per 100 000. In 1990, there were 354 064 302 (95% uncertainty interval: 338 174 876 to 371 610 802) new cases of injury globally, which increased to 520 710 288 (493 430 247 to 547 988 635) new cases in 2017. During this time, age-standardised incidence decreased non-significantly from 6824 (6534 to 7147) to 6763 (6412 to 7118) per 100 000. Between 1990 and 2017, age-standardised DALYs decreased from 4947 (4655 to 5233) per 100 000 to 3267 (3058 to 3505). Interpretation: Injuries are an important cause of health loss globally, though mortality has declined between 1990 and 2017. Future research in injury burden should focus on prevention in high-burden populations, improving data collection and ensuring access to medical care.publishedVersio

    Retro-biosynthetic screening of a modular pathway design achieves selective route for microbial synthesis of 4-methyl-pentanol

    Get PDF
    Increasingly complex metabolic pathways have been engineered by modifying natural pathways and establishing de novo pathways with enzymes from a variety of organisms. Here we apply retro-biosynthetic screening to a modular pathway design to identify a redox neutral, theoretically high yielding route to a branched C6 alcohol. Enzymes capable of converting natural E. coli metabolites into 4-methyl-pentanol (4MP) via coenzyme A (CoA)-dependent chemistry were taken from nine different organisms to form a ten-step de novo pathway. Selectivity for 4MP is enhanced through the use of key enzymes acting on acyl-CoA intermediates, a carboxylic acid reductase from Nocardia iowensis and an alcohol dehydrogenase from Leifsonia sp. strain S749. One implementation of the full pathway from glucose demonstrates selective carbon chain extension and acid reduction with 4MP constituting 81% (90±7 mg l⁻¹) of the observed alcohol products. The highest observed 4MP titre is 192±23 mg l⁻¹. These results demonstrate the ability of modular pathway screening to facilitate de novo pathway engineering.United States. Army Research Office (W911NF-09-0001
    corecore