2,034 research outputs found

    Fiber-Cavity-Based Optomechanical Device

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    We describe an optomechanical device consisting of a fiber-based optical cavity containing a silicon nitiride membrane. In comparison with typical free-space cavities, the fiber-cavity's small mode size (10 {\mu}m waist, 80 {\mu}m length) allows the use of smaller, lighter membranes and increases the cavity-membrane linear coupling to 3 GHz/nm and quadratic coupling to 20 GHz/nm^2. This device is also intrinsically fiber-coupled and uses glass ferrules for passive alignment. These improvements will greatly simplify the use of optomechanical systems, particularly in cryogenic settings. At room temperature, we expect these devices to be able to detect the shot noise of radiation pressure.Comment: 4 pages, 3 figures; the following article has been submitted to Applied Physics Letter

    The Effectiveness of Whole-Body-Vibration Training in Improving Hamstring Flexibility in Physically Active Adults

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    Clinical Scenario: Hamstring tightness is common among physically active individuals. In addition to limiting range of motion and increasing the risk of muscle strain, hamstring tightness contributes to a variety of orthopedic conditions. Therefore, clinicians continue to identify effective methods to increase flexibility. Although hamstring tightness is typically treated with common stretching techniques such as static stretching and proprioceptive neuromuscular facilitation, it has been suggested that whole-body-vibration (WBV) training may improve hamstring flexibility. Clinical Question: Can WBV training, used in isolation or in combination with common stretching protocols or exercise, improve hamstring flexibility in physically active young adults? Summary of Key Findings: Of the included studies, 4 demonstrated statistically significant improvements in hamstring flexibility in the intervention group, and 1 study found minor improvements over time in the intervention group after treatment. Clinical Bottom Line: There is moderate evidence to support the use of WBV training to improve hamstring flexibility in physically active young adults. Strength of Recommendation: There is grade B evidence that WBV training improves hamstring flexibility in physically active adults. The Centre of Evidence Based Medicine recommends a grade of B for level 2 evidence with consistent findings

    The METCRAX II Field Experiment: A Study of Downslope Windstorm-Type Flows in Arizona\u2019s Meteor Crater

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    The second Meteor Crater Experiment (METCRAX II) was conducted in October 2013 at Arizona\u2019s Meteor Crater. The experiment was designed to investigate nighttime downslope windstorm 12type flows that form regularly above the inner southwest sidewall of the 1.2-km diameter crater as a southwesterly mesoscale katabatic flow cascades over the crater rim. The objective of METCRAX II is to determine the causes of these strong, intermittent, and turbulent inflows that bring warm-air intrusions into the southwest part of the crater. This article provides an overview of the scientific goals of the experiment; summarizes the measurements, the crater topography, and the synoptic meteorology of the study period; and presents initial analysis results

    Towards a resource-based habitat approach for spatial modelling of vector-borne disease risks

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    Given the veterinary and public health impact of vector-borne diseases, there is a clear need to assess the suitability of landscapes for the emergence and spread of these diseases. Current approaches for predicting disease risks neglect key features of the landscape as components of the functional habitat of vectors or hosts, and hence of the pathogen. Empirical–statistical methods do not explicitly incorporate biological mechanisms, whereas current mechanistic models are rarely spatially explicit; both methods ignore the way animals use the landscape (i.e. movement ecology). We argue that applying a functional concept for habitat, i.e. the resource-based habitat concept (RBHC), can solve these issues. The RBHC offers a framework to identify systematically the different ecological resources that are necessary for the completion of the transmission cycle and to relate these resources to (combinations of) landscape features and other environmental factors. The potential of the RBHC as a framework for identifying suitable habitats for vector-borne pathogens is explored and illustrated with the case of bluetongue virus, a midge-transmitted virus affecting ruminants. The concept facilitates the study of functional habitats of the interacting species (vectors as well as hosts) and provides new insight into spatial and temporal variation in transmission opportunities and exposure that ultimately determine disease risks. It may help to identify knowledge gaps and control options arising from changes in the spatial configuration of key resources across the landscape. The RBHC framework may act as a bridge between existing mechanistic and statistical modelling approaches

    Removal processes for tributyltin during municipal wastewater treatment

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2013 Springer.The fate and behaviour of tributyltin (TBT) at two wastewater treatment works was examined. Both sites had two inlet streams, and each utilised high rate biological filters (biofilters) on one the streams, before treatment of the combined flows on trickling filters, with one having additional tertiary processes, installed to remove ammonia and solids. The study was designed to determine if these processes enhanced the removal of TBT. Degradation of TBT was observed in one of the biofilters, possibly as a result of temperature and hydraulic loading. At the treatment works with tertiary processes, the mass flux showed the overall removal of TBT was 68 %, predominantly due to removal with solids in the primary settlement processes. However, overall removal of 95 % was observed in the conventional trickling filter works with 94 % of this due to biodegradation in the trickling filter. The two works both removed TBT, but at different treatment stages and by different processes. Differences in the form (solubility) of TBT in the influent may have attributed to this, although further understanding of factors controlling degradation would allow for a more complete assessment of the potential of biological processes to remove hazardous compounds from wastewaters.United Utilities PL

    Determinants for the success of software startups: Insights from a regional cluster

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    In recent years, we have seen a growing interest in technology-based companies and intensive knowledge. Several regional clusters have appeared supported in dynamic entrepreneurial ecosystems which, alongside intrinsic aspects of the business, are important determinants of the success of new companies. However, most startups created in these innovation-oriented spaces do not survive the first years of life, due to the high competitiveness of the technological market, due to deficiencies in the business model, due to the support conditions provided by the surrounding ecosystem, and finally due to a weak adjustment between all these dimensions. Among several models available, the Early-Life Decision Model (ELDM) presents itself as an interesting framework for studying the development and success conditions of software companies. This article discusses the application of the ELDM based on a series of interviews conducted to 15 Portuguese software startups installed in a technological cluster located in the northeast of Portugal. Based on the results obtained, it was appropriate to add a new dimension to the ELDM model (learning) and complementing it with the perspectives of the business type and internal versus external determinants.This work was supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT (Fundação para a Ciência e a Tecnologia) within the Project Scope: UID/CEC/00319/2013

    PCR-GLOBWB 2: a 5 arcmin global hydrological and water resources model

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    We present PCR-GLOBWB 2, a global hydrology and water resources model. Compared to previous versions of PCR-GLOBWB, this version fully integrates water use. Sector-specific water demand, groundwater and surface water withdrawal, water consumption, and return flows are dynamically calculated at every time step and interact directly with the simulated hydrology. PCR-GLOBWB 2 has been fully rewritten in Python and PCRaster Python and has a modular structure, allowing easier replacement, maintenance, and development of model components. PCR-GLOBWB 2 has been implemented at 5 arcmin resolution, but a version parameterized at 30 arcmin resolution is also available. Both versions are available as open-source codes on https://github.com/UU-Hydro/PCR-GLOBWB_model (Sutanudjaja et al., 2017a). PCR-GLOBWB 2 has its own routines for groundwater dynamics and surface water routing. These relatively simple routines can alternatively be replaced by dynamically coupling PCR-GLOBWB 2 to a global two-layer groundwater model and 1-D–2-D hydrodynamic models. Here, we describe the main components of the model, compare results of the 30 and 5 arcmin versions, and evaluate their model performance using Global Runoff Data Centre discharge data. Results show that model performance of the 5 arcmin version is notably better than that of the 30 arcmin version. Furthermore, we compare simulated time series of total water storage (TWS) of the 5 arcmin model with those observed with GRACE, showing similar negative trends in areas of prevalent groundwater depletion. Also, we find that simulated total water withdrawal matches reasonably well with reported water withdrawal from AQUASTAT, while water withdrawal by source and sector provide mixed results

    Protocol for the 'e-Nudge trial' : a randomised controlled trial of electronic feedback to reduce the cardiovascular risk of individuals in general practice [ISRCTN64828380]

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    Background: Cardiovascular disease (including coronary heart disease and stroke) is a major cause of death and disability in the United Kingdom, and is to a large extent preventable, by lifestyle modification and drug therapy. The recent standardisation of electronic codes for cardiovascular risk variables through the United Kingdom's new General Practice contract provides an opportunity for the application of risk algorithms to identify high risk individuals. This randomised controlled trial will test the benefits of an automated system of alert messages and practice searches to identify those at highest risk of cardiovascular disease in primary care databases. Design: Patients over 50 years old in practice databases will be randomised to the intervention group that will receive the alert messages and searches, and a control group who will continue to receive usual care. In addition to those at high estimated risk, potentially high risk patients will be identified who have insufficient data to allow a risk estimate to be made. Further groups identified will be those with possible undiagnosed diabetes, based either on elevated past recorded blood glucose measurements, or an absence of recent blood glucose measurement in those with established cardiovascular disease. Outcome measures: The intervention will be applied for two years, and outcome data will be collected for a further year. The primary outcome measure will be the annual rate of cardiovascular events in the intervention and control arms of the study. Secondary measures include the proportion of patients at high estimated cardiovascular risk, the proportion of patients with missing data for a risk estimate, and the proportion with undefined diabetes status at the end of the trial

    Light absorption by anthocyanins in juvenile, stressed, and senescing leaves

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    The optical properties of leaves from five species, Norway maple (Acer platanoides L.), cotoneaster (Cotoneaster alaunica Golite), hazel (Corylus avellana L.), Siberian dogwood (Cornus alba L.), and Virginia creeper (Parthenocissus quinquefolia (L.) Planch.), differing in pigment composition and at different stages of ontogenesis, were studied. Anthocyanin absorption maxima in vivo, as estimated with spectrophotometry of intact anthocyanic versus acyanic leaves and microspectrophotometry of vacuoles in the leaf cross-sections, were found between 537 nm and 542 nm, showing a red shift of 5–20 nm compared with the corresponding maxima in acidic water–methanol extracts. In non-senescent leaves, strong anthocyanin absorption was found between 500 nm and 600 nm (with a 70–80 nm apparent bandwidth). By and large, absorption by anthocyanin in leaves followed a modified form of the Lambert–Beer law, showing a linear trend up to a content of nearly 50 nmol cm−2, and permitting thereby a non-invasive determination of anthocyanin content. The apparent specific absorption coefficients of anthocyanins at 550 nm showed no substantial dependence on the species. Anthocyanin contribution to total light absorption at 550 nm was followed in maple leaves in the course of autumn senescence. Photoprotection by vacuolar anthocyanins is discussed with special regard to their distribution within a leaf; radiation screening by anthocyanins predominantly localized in the epidermal cells in A. platanoides and C. avellana leaves was also evaluated
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