SHEDS-Multimedia Model Version 3 (a) Technical Manual; (b) User Guide; and (c) Executable File to Launch SAS Program and Install Model

Science.gov (United States)

Reliable models for assessing human exposures are important for understanding health risks from chemicals. The Stochastic Human Exposure and Dose Simulation model for multimedia, multi-route/pathway chemicals (SHEDS-Multimedia), developed by EPA’s Office of Research and Developm...

Afterglow Observations Shed New Light on the Nature of X-ray Flashes

Energy Technology Data Exchange (ETDEWEB)

Granot, J

2005-02-17

X-ray flashes (XRFs) and X-ray rich gamma-ray bursts (XRGRBs) share many observational characteristics with long duration ({approx}> 2 s) GRBs, but the reason for which the spectral energy distribution of their prompt emission peaks at lower photon energies, E{sub p}, is still a subject of debate. Although many different models have been invoked in order to explain the lower values of E{sub p}, their implications for the afterglow emission were not considered in most cases, mainly because observations of XRF afterglows have become available only recently. Here we examine the predictions of the various XRF models for the afterglow emission, and test them against the observations of XRF 030723 and XRGRB 041006, the events with the best monitored afterglow light curves in their respective class. We show that most existing XRF models are hard to reconcile with the observed afterglow light curves, which are very flat at early times. Such light curves are, however, naturally produced by a roughly uniform jet with relatively sharp edges that is viewed off-axis (i.e. from outside of the jet aperture). This type of model self consistently accommodates both the observed prompt emission and the afterglow light curves of XRGRB 041006 and XRF 030723, implying viewing angles {theta}{sub obs} from the jet axis of ({theta}{sub obs}-{theta}{sub 0}) {approx} 0.15 {theta}{sub 0} and ({theta}{sub obs}-{theta}{sub 0}) {approx} {theta}{sub 0}, respectively, where {theta}{sub 0} {approx} 3{sup o} is the half-opening angle of the jet. This suggests that GRBs, XRGRBs and XRFs are intrinsically similar relativistic jets viewed from different angles. It is then natural to identify GRBs with {gamma}({theta}{sub obs} - {theta}{sub 0}) {approx}< 1, XRGRBs with 1 {approx}< ({theta}{sub obs} - {theta}{sub 0}) {approx}< a few, and XRFs with {gamma}({theta}{sub obs} - {theta}{sub 0}) {approx}> a few, where {gamma} is the Lorentz factor of the outflow near the edge of the jet from which most of the

Shedding Light on the Cosmic Skeleton

Science.gov (United States)

2009-11-01

Astronomers have tracked down a gigantic, previously unknown assembly of galaxies located almost seven billion light-years away from us. The discovery, made possible by combining two of the most powerful ground-based telescopes in the world, is the first observation of such a prominent galaxy structure in the distant Universe, providing further insight into the cosmic web and how it formed. "Matter is not distributed uniformly in the Universe," says Masayuki Tanaka from ESO, who led the new study. "In our cosmic vicinity, stars form in galaxies and galaxies usually form groups and clusters of galaxies. The most widely accepted cosmological theories predict that matter also clumps on a larger scale in the so-called 'cosmic web', in which galaxies, embedded in filaments stretching between voids, create a gigantic wispy structure." These filaments are millions of light years long and constitute the skeleton of the Universe: galaxies gather around them, and immense galaxy clusters form at their intersections, lurking like giant spiders waiting for more matter to digest. Scientists are struggling to determine how they swirl into existence. Although massive filamentary structures have been often observed at relatively small distances from us, solid proof of their existence in the more distant Universe has been lacking until now. The team led by Tanaka discovered a large structure around a distant cluster of galaxies in images they obtained earlier. They have now used two major ground-based telescopes to study this structure in greater detail, measuring the distances from Earth of over 150 galaxies, and, hence, obtaining a three-dimensional view of the structure. The spectroscopic observations were performed using the VIMOS instrument on ESO's Very Large Telescope and FOCAS on the Subaru Telescope, operated by the National Astronomical Observatory of Japan. Thanks to these and other observations, the astronomers were able to make a real demographic study of this structure

HydroSHEDS: A global comprehensive hydrographic dataset

Science.gov (United States)

Wickel, B. A.; Lehner, B.; Sindorf, N.

2007-12-01

The Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales (HydroSHEDS) is an innovative product that, for the first time, provides hydrographic information in a consistent and comprehensive format for regional and global-scale applications. HydroSHEDS offers a suite of geo-referenced data sets, including stream networks, watershed boundaries, drainage directions, and ancillary data layers such as flow accumulations, distances, and river topology information. The goal of developing HydroSHEDS was to generate key data layers to support regional and global watershed analyses, hydrological modeling, and freshwater conservation planning at a quality, resolution and extent that had previously been unachievable. Available resolutions range from 3 arc-second (approx. 90 meters at the equator) to 5 minute (approx. 10 km at the equator) with seamless near-global extent. HydroSHEDS is derived from elevation data of the Shuttle Radar Topography Mission (SRTM) at 3 arc-second resolution. The original SRTM data have been hydrologically conditioned using a sequence of automated procedures. Existing methods of data improvement and newly developed algorithms have been applied, including void filling, filtering, stream burning, and upscaling techniques. Manual corrections were made where necessary. Preliminary quality assessments indicate that the accuracy of HydroSHEDS significantly exceeds that of existing global watershed and river maps. HydroSHEDS was developed by the Conservation Science Program of the World Wildlife Fund (WWF) in partnership with the U.S. Geological Survey (USGS), the International Centre for Tropical Agriculture (CIAT), The Nature Conservancy (TNC), and the Center for Environmental Systems Research (CESR) of the University of Kassel, Germany.

77 FR 53884 - Automatic Underfrequency Load Shedding and Load Shedding Plans Reliability Standards; Notice of...

Science.gov (United States)

2012-09-04

... Underfrequency Load Shedding and Load Shedding Plans Reliability Standards; Notice of Compliance Filing Take notice that on August 9, 2012, North American Electric Reliability Corporation submitted a compliance... Load Shedding Plans Reliability Standards, 139 FERC ] 61,098, (Order No. 763) (2012). Any person...

Shedding light on diatom photonics by means of digital holography.

Science.gov (United States)

Di Caprio, Giuseppe; Coppola, Giuseppe; De Stefano, Luca; De Stefano, Mario; Antonucci, Alessandra; Congestri, Roberta; De Tommasi, Edoardo

2014-05-01

Diatoms are among the dominant phytoplankters in the world's oceans, and their external silica investments, resembling artificial photonic crystals, are expected to play an active role in light manipulation. Digital holography allowed studying the interaction with light of Coscinodiscus wailesii cell wall reconstructing the light confinement inside the cell cytoplasm, condition that is hardly accessible via standard microscopy. The full characterization of the propagated beam, in terms of quantitative phase and intensity, removed a long-standing ambiguity about the origin of the light confinement. The data were discussed in the light of living cell behavior in response to their environment. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Systemic Immune Activation and HIV Shedding in the Female Genital Tract.

Science.gov (United States)

Spencer, LaShonda Y; Christiansen, Shawna; Wang, Chia-Hao H; Mack, Wendy J; Young, Mary; Strickler, Howard D; Anastos, Kathryn; Minkoff, Howard; Cohen, Mardge; Geenblatt, Ruth M; Karim, Roksana; Operskalski, Eva; Frederick, Toni; Homans, James D; Landay, Alan; Kovacs, Andrea

2016-02-01

Plasma HIV RNA is the most significant determinant of cervical HIV shedding. However, shedding is also associated with sexually transmitted infections (STIs) and cervical inflammation. The mechanism by which this occurs is poorly understood. There is evidence that systemic immune activation promotes viral entry, replication, and HIV disease progression. We hypothesized that systemic immune activation would be associated with an increase in HIV genital shedding. Clinical assessments, HIV RNA in plasma and genital secretions, and markers of immune activation (CD38(+)DR(+) and CD38(-)DR(-)) on CD4(+) and CD8(+) T cells in blood were evaluated in 226 HIV+ women enrolled in the Women's Interagency HIV Study. There were 569 genital evaluations of which 159 (28%) exhibited HIV RNA shedding, defined as HIV viral load >80 copies per milliliter. We tested associations between immune activation and shedding using generalized estimating equations with logit link function. In the univariate model, higher levels of CD4(+) and CD8(+) T-cell activation in blood were significantly associated with genital tract shedding. However, in the multivariate model adjusting for plasma HIV RNA, STIs, and genital tract infections, only higher levels of resting CD8(+) T cells (CD38(-)DR(-)) were significantly inversely associated with HIV shedding in the genital tract (odds ratios = 0.44, 95% confidence interval: 0.21 to 0.9, P = 0.02). The association of systemic immune activation with genital HIV shedding is multifactorial. Systemic T-cell activation is associated with genital tract shedding in univariate analysis but not when adjusting for plasma HIV RNA, STIs, and genital tract infections. In addition, women with high percentage of resting T cells are less likely to have HIV shedding compared with those with lower percentages. These findings suggest that a higher percentage of resting cells, as a result of maximal viral suppression with treatment, may decrease local genital activation, HIV

Replication, pathogenicity, shedding, and transmission of Zaire ebolavirus in pigs.

Science.gov (United States)

Kobinger, Gary P; Leung, Anders; Neufeld, James; Richardson, Jason S; Falzarano, Darryl; Smith, Greg; Tierney, Kevin; Patel, Ami; Weingartl, Hana M

2011-07-15

(See the editorial commentary by Bausch, on pages 179-81.) Reston ebolavirus was recently detected in pigs in the Philippines. Specific antibodies were found in pig farmers, indicating exposure to the virus. This important observation raises the possibility that pigs may be susceptible to Ebola virus infection, including from other species, such as Zaire ebolavirus (ZEBOV), and can transmit to other susceptible hosts. This study investigated whether ZEBOV, a species commonly reemerging in central Africa, can replicate and induce disease in pigs and can be transmitted to naive animals. Domesticated Landrace pigs were challenged through mucosal exposure with a total of 1 ×10(6) plaque-forming units of ZEBOV and monitored for virus replication, shedding, and pathogenesis. Using similar conditions, virus transmission from infected to naive animals was evaluated in a second set of pigs. Following mucosal exposure, pigs replicated ZEBOV to high titers (reaching 10(7) median tissue culture infective doses/mL), mainly in the respiratory tract, and developed severe lung pathology. Shedding from the oronasal mucosa was detected for up to 14 days after infection, and transmission was confirmed in all naive pigs cohabiting with inoculated animals. These results shed light on the susceptibility of pigs to ZEBOV infection and identify an unexpected site of virus amplification and shedding linked to transmission of infectious virus.

Lighting up your product! : The influence of retail lighting on product perception

NARCIS (Netherlands)

Creusen, M.E.H.; Pont, S.C.; Schoormans, J.P.L.

2017-01-01

This research is one of the first attempts to shed light on the influence of different lighting characteristics on consumer product perception. Study 1 looked at the influence of light level (i.e., brightness) and color temperature on consumer perception of a sneaker and a toaster. Study 2 assessed

Shedding light on El Farol

Science.gov (United States)

Challet, Damien; Marsili, M.; Ottino, Gabriele

2004-02-01

We mathematize El Farol bar problem and transform it into a workable model. We find general conditions on the predictor space under which the convergence of the average attendance to the resource level does not require any intelligence on the side of the agents. Secondly, specializing to a particular ensemble of continuous strategies yields a model similar to the Minority Game. Statistical physics of disordered systems allows us to derive a complete understanding of the complex behavior of this model, on the basis of its phase diagram.

Coxiella burnetii shedding by dairy cows.

Science.gov (United States)

Guatteo, Raphaël; Beaudeau, François; Joly, Alain; Seegers, Henri

2007-01-01

While shedding routes of Coxiella burnetii are identified, the characteristics of Coxiella shedding are still widely unknown, especially in dairy cattle. However, this information is crucial to assess the natural course of Coxiella burnetii infection within a herd and then to elaborate strategies to limit the risks of transmission between animals and to humans. The present study aimed at (i) describing the characteristics of Coxiella burnetii shedding by dairy cows (in milk, vaginal mucus, faeces) in five infected dairy herds, and at (ii) investigating the possible relationships between shedding patterns and serological responses. A total of 145 cows were included in a follow-up consisting of seven concomitant samplings of milk, vaginal mucus, faeces and blood (Day 0, D7, D14, D21, D28, D63, D90). Detection and quantification of Coxiella burnetii titres were performed in milk, vaginal mucus and faeces samples using real-time PCR assay, while antibodies against Coxiella were detected using an ELISA technique. For a given shedding route, and a given periodicity (weekly or monthly), cows were gathered into different shedding kinetic patterns according to the sequence of PCR responses. Distribution of estimated titres in Coxiella burnetii was described according to shedding kinetic patterns. Coxiella burnetii shedding was found scarcely and sporadically in faeces. Vaginal mucus shedding concerned almost 50% of the cows studied and was found intermittently or sporadically, depending on the periodicity considered. Almost 40% of cows were detected as milk shedders, with two predominant shedding patterns: persistent and sporadic, regardless of the sampling periodicity. Significantly higher estimated titres in Coxiella burnetii were observed in cows with persistent shedding patterns suggesting the existence of heavy shedder cows. These latter cows were mostly, persistently highly-seropositive, suggesting that repeated serological testings could be a reliable tool to screen

Protoearth mass shedding and the origin of the moon

Science.gov (United States)

Boss, A. P.

1986-01-01

Darwin's (1980) theory of lunar formation from the earth by means of a rotationally driven dynamic fission instability is presently considered in view of viscous shear's maintenance of solid body rotation throughout the protoearth's accretion phase. Assuming the appropriateness of a polytropic account of the protoearth, it is unlikely that dynamic fission could have occurred; instantaneous spin-up following a giant impact would instead have led to mass shedding. The dynamical phenomenon of mass shedding is here explored on the basis of numerical models for a self-gravitating, axisymmetric, polytropic and dissipative protoearth. It is concluded that mass shedding from the protoearth mantle after a giant impact and explosion could have contributed substantial matter to a lunar disk.

Children's residential exposure to chlorpyrifos: Application of CPPAES field measurements of chlorpyrifos and TCPy within MENTOR/SHEDS-Pesticides model

International Nuclear Information System (INIS)

Hore, Paromita; Zartarian, Valerie; Xue Jianping; Ozkaynak, Haluk; Wang, S.-W.; Yang, Y.-C.; Chu, P.-Ling; Sheldon, Linda; Robson, Mark; Needham, Larry; Barr, Dana; Freeman, Natalie; Georgopoulos, Panos; Lioy, Paul J.

2006-01-01

The comprehensive individual field-measurements on non-dietary exposure collected in the Children's-Post-Pesticide-Application-Exposure-Study (CPPAES) were used within MENTOR/SHEDS-Pesticides, a physically based stochastic human exposure and dose model. In this application, however, the model was run deterministically. The MENTOR/SHEDS-Pesticides employed the CPPAES as input variables to simulate the exposure and the dose profiles for seven children over a 2-week post-application period following a routine residential and professional indoor crack-and-crevice chlorpyrifos application. The input variables were obtained from a personal activity diary, microenvironmental measurements and personal biomonitoring data obtained from CPPAES samples collected from the individual children and in their homes. Simulation results were compared with CPPAES field measured values obtained from the children's homes to assess the utility of the different microenvironmental data collected in CPPAES, i.e. indicator toys and wipe samplers to estimate aggregate exposures that can be result from one or more exposure pathways and routes. The final analyses of the database involved comparisons of the actual data obtained from the individual biomarker samples of a urinary metabolite of chlorpyrifos (TCPy) and the values predicted by MENTOR/SHEDS-Pesticides using the CPPAES-derived variables. Because duplicate diet samples were not part of the CPPAES study design, SHEDs-Pesticides simulated dose profiles did not account for the dietary route. The research provided more confidence in the types of data that can be used in the inhalation and dermal contact modules of MENTOR/SHEDS-Pesticides to predict the pesticide dose received by a child. It was determined that we still need additional understanding about: (1) the types of activities and durations of activities that result in non-dietary ingestion of pesticides and (2) the influence of dietary exposures on the levels of TCPy found in the

A previously undescribed organic residue sheds light on heat treatment in the Middle Stone Age.

Science.gov (United States)

Schmidt, Patrick; Porraz, Guillaume; Bellot-Gurlet, Ludovic; February, Edmund; Ligouis, Bertrand; Paris, Céline; Texier, Pierre-Jean; Parkington, John E; Miller, Christopher E; Nickel, Klaus G; Conard, Nicholas J

2015-08-01

South Africa has in recent years gained increasing importance for our understanding of the evolution of 'modern human behaviour' during the Middle Stone Age (MSA). A key element in the suite of behaviours linked with modern humans is heat treatment of materials such as ochre for ritual purposes and stone prior to tool production. Until now, there has been no direct archaeological evidence for the exact procedure used in the heat treatment of silcrete. Through the analysis of heat-treated artefacts from the Howiesons Poort of Diepkloof Rock Shelter, we identified a hitherto unknown type of organic residue - a tempering-residue - that sheds light on the processes used for heat treatment in the MSA. This black film on the silcrete surface is an organic tar that contains microscopic fragments of charcoal and formed as a residue during the direct contact of the artefacts with hot embers of green wood. Our results suggest that heat treatment of silcrete was conducted directly using an open fire, similar to those likely used for cooking. These findings add to the discussion about the complexity of MSA behaviour and appear to contradict previous studies that had suggested that heat treatment of silcrete was a complex (i.e., requiring a large number of steps for its realization) and resource-consuming procedure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Under-Frequency Load Shedding Technique Considering Event-Based for an Islanded Distribution Network

Directory of Open Access Journals (Sweden)

Hasmaini Mohamad

2016-06-01

Full Text Available One of the biggest challenge for an islanding operation is to sustain the frequency stability. A large power imbalance following islanding would cause under-frequency, hence an appropriate control is required to shed certain amount of load. The main objective of this research is to develop an adaptive under-frequency load shedding (UFLS technique for an islanding system. The technique is designed considering an event-based which includes the moment system is islanded and a tripping of any DG unit during islanding operation. A disturbance magnitude is calculated to determine the amount of load to be shed. The technique is modeled by using PSCAD simulation tool. A simulation studies on a distribution network with mini hydro generation is carried out to evaluate the UFLS model. It is performed under different load condition: peak and base load. Results show that the load shedding technique have successfully shed certain amount of load and stabilized the system frequency.

Circulation shedding in viscous starting flow past a flat plate

International Nuclear Information System (INIS)

Nitsche, Monika; Xu, Ling

2014-01-01

Numerical simulations of viscous flow past a flat plate moving in the direction normal to itself reveal details of the vortical structure of the flow. At early times, most of the vorticity is attached to the plate. This paper introduces a definition of the shed circulation at all times and shows that it indeed represents vorticity that separates and remains separated from the plate. During a large initial time period, the shed circulation satisfies the scaling laws predicted for self-similar inviscid separation. Various contributions to the circulation shedding rate are presented. The results show that during this initial time period, viscous diffusion of vorticity out of the vortex is significant but appears to be independent of the value of the Reynolds number. At later times, the departure of the shed circulation from its large Reynolds number behaviour is significantly affected by diffusive loss of vorticity through the symmetry axis. A timescale is proposed that describes when the viscous loss through the axis becomes relevant. The simulations provide benchmark results to evaluate simpler separation models such as point vortex and vortex sheet models. A comparison with vortex sheet results is included. (paper)

Shedding light on neutrino masses with dark forces

Energy Technology Data Exchange (ETDEWEB)

Batell, Brian [Pittsburgh Particle Physics, Astrophysics, and Cosmology Center,Department of Physics and Astronomy, University of Pittsburgh, PA 15260 (United States); Pospelov, Maxim [Perimeter Institute for Theoretical Physics,Waterloo, ON N2J 2W9 (Canada); Department of Physics and Astronomy, University of Victoria,Victoria, BC V8P 5C2 (Canada); Shuve, Brian [SLAC National Accelerator Laboratory,2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

2016-08-08

Heavy right-handed neutrinos, N, provide the simplest explanation for the origin of light neutrino masses and mixings. If M{sub N} is at or below the weak scale, direct experimental discovery of these states is possible at accelerator experiments such as the LHC or new dedicated beam dump experiments; in these experiments, N decays after traversing a macroscopic distance from the collision point. The experimental sensitivity to right-handed neutrinos is significantly enhanced if there is a new “dark” gauge force connecting them to the Standard Model (SM), and detection of N can be the primary discovery mode for the new dark force itself. We take the well-motivated example of a B−L gauge symmetry and analyze the sensitivity to displaced decays of N produced via the new gauge interaction in two experiments: the LHC and the proposed SHiP beam dump experiment. In the most favorable case in which the mediator can be produced on-shell and decays to right handed neutrinos (pp→X+V{sub B−L}→X+NN), the sensitivity reach is controlled by the square of the B−L gauge coupling. We demonstrate that these experiments could access neutrino parameters responsible for the observed SM neutrino masses and mixings in the most straightforward implementation of the see-saw mechanism.

CHILDREN'S RESIDENTIAL EXPOSURE TO CHLORPYRIFOS: APPLICATION OF CPPAES FIELD MEASUREMENTS OF CHLORPYRIFOS AND TCPY WITHIN MENTOR/SHEDS PESTICIDES MODEL

Science.gov (United States)

The comprehensive individual field-measurements on non-dietary exposure collected in the Children's-Post-Pesticide-Application-Exposure-Study (CPPAES) were used within MENTOR/SHEDS-Pesticides, a physically based stochastic human exposure and dose model. In this application, howev...

Children's residential exposure to chlorpyrifos: Application of CPPAES field measurements of chlorpyrifos and TCPy within MENTOR/SHEDS-Pesticides model

Energy Technology Data Exchange (ETDEWEB)

Hore, Paromita [Environmental and Occupational Health Sciences Institute (EOHSI), Rutgers University and the University of Medicine and Dentistry of New Jersey (UMDNJ), Robert Wood Johnson Medical School, 170 Frelinghuysen Road, Piscataway, NJ 08855 (United States)]|[New York City Department of Health, 253 Broadway New York, New York 10007 (United States); Zartarian, Valerie; Xue Jianping; Ozkaynak, Haluk [National Exposure Research Laboratory, U.S. EPA, 109 TW Alexander Drive, Research Triangle Park, NC 27709 (United States); Wang, S.-W.; Yang, Y.-C.; Chu, P.-Ling; Robson, Mark; Georgopoulos, Panos [Environmental and Occupational Health Sciences Institute (EOHSI), Rutgers University and the University of Medicine and Dentistry of New Jersey (UMDNJ), Robert Wood Johnson Medical School, 170 Frelinghuysen Road, Piscataway, NJ 08855 (United States); Sheldon, Linda [National Exposure Research Laboratory, U.S. EPA, 109 TW Alexander Drive, Research Triangle Park, NC 27709 (United States); Needham, Larry Barr, Dana [Contemporary Pesticide Laboratory, Centers for Disease Control, 4770 Buford Highway, Atlanta, GA 30341 (United States); Freeman, Natalie [Environmental and Occupational Health Sciences Institute (EOHSI), Rutgers University and the University of Medicine and Dentistry of New Jersey (UMDNJ), Robert Wood Johnson Medical School, 170 Frelinghuysen Road, Piscataway, NJ 08855 (United States)]|[University of Florida, Gainesville, FL 32611 (United States); Lioy, Paul J. [Environmental and Occupational Health Sciences Institute (EOHSI), Rutgers University and the University of Medicine and Dentistry of New Jersey (UMDNJ), Robert Wood Johnson Medical School, 170 Frelinghuysen Road, Piscataway, NJ 08855 (United States)]. E-mail: plioy@eohsi.rutgers.edu

2006-08-01

The comprehensive individual field-measurements on non-dietary exposure collected in the Children's-Post-Pesticide-Application-Exposure-Study (CPPAES) were used within MENTOR/SHEDS-Pesticides, a physically based stochastic human exposure and dose model. In this application, however, the model was run deterministically. The MENTOR/SHEDS-Pesticides employed the CPPAES as input variables to simulate the exposure and the dose profiles for seven children over a 2-week post-application period following a routine residential and professional indoor crack-and-crevice chlorpyrifos application. The input variables were obtained from a personal activity diary, microenvironmental measurements and personal biomonitoring data obtained from CPPAES samples collected from the individual children and in their homes. Simulation results were compared with CPPAES field measured values obtained from the children's homes to assess the utility of the different microenvironmental data collected in CPPAES, i.e. indicator toys and wipe samplers to estimate aggregate exposures that can be result from one or more exposure pathways and routes. The final analyses of the database involved comparisons of the actual data obtained from the individual biomarker samples of a urinary metabolite of chlorpyrifos (TCPy) and the values predicted by MENTOR/SHEDS-Pesticides using the CPPAES-derived variables. Because duplicate diet samples were not part of the CPPAES study design, SHEDs-Pesticides simulated dose profiles did not account for the dietary route. The research provided more confidence in the types of data that can be used in the inhalation and dermal contact modules of MENTOR/SHEDS-Pesticides to predict the pesticide dose received by a child. It was determined that we still need additional understanding about: (1) the types of activities and durations of activities that result in non-dietary ingestion of pesticides and (2) the influence of dietary exposures on the levels of TCPy found

Hair shedding score may affect body temperature more than hair coat color during heat stress in weaned beef heifers.

Science.gov (United States)

The objective of this study was to evaluate the effect of hair shedding score and hair coat color on the vaginal temperature (VT) of calves during heat stress. Weaned Bos taurus beef heifers (n = 32; BW = 282 ± 6.4 kg) were assigned to a hair coat color class (BLACK; RED; or LIGHT, where LIGHT = yel...

Process based model sheds light on climate sensitivity of Mediterranean tree-ring width

Directory of Open Access Journals (Sweden)

R. Touchan

2012-03-01

Full Text Available We use the process-based VS (Vaganov-Shashkin model to investigate whether a regional Pinus halepensis tree-ring chronology from Tunisia can be simulated as a function of climate alone by employing a biological model linking day length and daily temperature and precipitation (AD 1959–2004 from a climate station to ring-width variations. We check performance of the model on independent data by a validation exercise in which the model's parameters are tuned using data for 1982–2004 and the model is applied to generate tree-ring indices for 1959–1981. The validation exercise yields a highly significant positive correlation between the residual chronology and estimated growth curve (r=0.76 p<0.0001, n=23. The model shows that the average duration of the growing season is 191 days, with considerable variation from year to year. On average, soil moisture limits tree-ring growth for 128 days and temperature for 63 days. Model results depend on chosen values of parameters, in particular a parameter specifying a balance ratio between soil moisture and precipitation. Future work in the Mediterranean region should include multi-year natural experiments to verify patterns of cambial-growth variation suggested by the VS model.

Quantifying Children's Aggregate (Dietary and Residential) Exposure and Dose to Permethin: Application and Evaluation of EPA's Probabilistic SHED-Multimedia Model

Science.gov (United States)

Reliable, evaluated human exposure and dose models are important for understanding the health risks from chemicals. A case study focusing on permethrin was conducted because of this insecticide’s widespread use and potential health effects. SHEDS-Multimedia was applied to estimat...

Information-Theoretic Approach May Shed a Light to a Better Understanding and Sustaining the Integrity of Ecological-Societal Systems under Changing Climate

Science.gov (United States)

Kim, J.

2016-12-01

Considering high levels of uncertainty, epistemological conflicts over facts and values, and a sense of urgency, normal paradigm-driven science will be insufficient to mobilize people and nation toward sustainability. The conceptual framework to bridge the societal system dynamics with that of natural ecosystems in which humanity operates remains deficient. The key to understanding their coevolution is to understand `self-organization.' Information-theoretic approach may shed a light to provide a potential framework which enables not only to bridge human and nature but also to generate useful knowledge for understanding and sustaining the integrity of ecological-societal systems. How can information theory help understand the interface between ecological systems and social systems? How to delineate self-organizing processes and ensure them to fulfil sustainability? How to evaluate the flow of information from data through models to decision-makers? These are the core questions posed by sustainability science in which visioneering (i.e., the engineering of vision) is an essential framework. Yet, visioneering has neither quantitative measure nor information theoretic framework to work with and teach. This presentation is an attempt to accommodate the framework of self-organizing hierarchical open systems with visioneering into a common information-theoretic framework. A case study is presented with the UN/FAO's communal vision of climate-smart agriculture (CSA) which pursues a trilemma of efficiency, mitigation, and resilience. Challenges of delineating and facilitating self-organizing systems are discussed using transdisciplinary toold such as complex systems thinking, dynamic process network analysis and multi-agent systems modeling. Acknowledgments: This study was supported by the Korea Meteorological Administration Research and Development Program under Grant KMA-2012-0001-A (WISE project).

INTERNAL STRUCTURE OF ASTEROIDS HAVING SURFACE SHEDDING DUE TO ROTATIONAL INSTABILITY

Energy Technology Data Exchange (ETDEWEB)

Hirabayashi, Masatoshi [Research Associate, Colorado Center for Astrodynamics Research, Aerospace Engineering Sciences, University of Colorado Boulder (United States); Sánchez, Diego Paul [Senior Research Associate, Colorado Center for Astrodynamics Research, Aerospace Engineering Sciences, University of Colorado Boulder (United States); Scheeres, Daniel J., E-mail: masatoshi.hirabayashi@colorado.edu [Richard Seebass Chair, Professor, Colorado Center for Astrodynamics Research, Aerospace Engineering Sciences, University of Colorado Boulder (United States)

2015-07-20

Surface shedding of an asteroid is a failure mode where surface materials fly off due to strong centrifugal forces beyond the critical spin period, while the internal structure does not deform significantly. This paper proposes a possible structure of an asteroid interior that leads to surface shedding due to rapid rotation rates. A rubble pile asteroid is modeled as a spheroid composed of a surface shell and a concentric internal core, the entire assembly called the test body. The test body is assumed to be uniformly rotating around a constant rotation axis. We also assume that while the bulk density and the friction angle are constant, the cohesion of the surface shell is different from that of the internal core. First, developing an analytical model based on limit analysis, we provide the upper and lower bounds for the actual surface shedding condition. Second, we use a Soft-sphere Discrete Element Method (SSDEM) to study dynamical deformation of the test body due to a quasi-static spin-up. In this paper we show the consistency of both approaches. Additionally, the SSDEM simulations show that the initial failure always occurs locally and not globally. In addition, as the core becomes larger, the size of lofted components becomes smaller. These results imply that if there is a strong core in a progenitor body, surface shedding is the most likely failure mode.

INTERNAL STRUCTURE OF ASTEROIDS HAVING SURFACE SHEDDING DUE TO ROTATIONAL INSTABILITY

International Nuclear Information System (INIS)

Hirabayashi, Masatoshi; Sánchez, Diego Paul; Scheeres, Daniel J.

2015-01-01

Surface shedding of an asteroid is a failure mode where surface materials fly off due to strong centrifugal forces beyond the critical spin period, while the internal structure does not deform significantly. This paper proposes a possible structure of an asteroid interior that leads to surface shedding due to rapid rotation rates. A rubble pile asteroid is modeled as a spheroid composed of a surface shell and a concentric internal core, the entire assembly called the test body. The test body is assumed to be uniformly rotating around a constant rotation axis. We also assume that while the bulk density and the friction angle are constant, the cohesion of the surface shell is different from that of the internal core. First, developing an analytical model based on limit analysis, we provide the upper and lower bounds for the actual surface shedding condition. Second, we use a Soft-sphere Discrete Element Method (SSDEM) to study dynamical deformation of the test body due to a quasi-static spin-up. In this paper we show the consistency of both approaches. Additionally, the SSDEM simulations show that the initial failure always occurs locally and not globally. In addition, as the core becomes larger, the size of lofted components becomes smaller. These results imply that if there is a strong core in a progenitor body, surface shedding is the most likely failure mode

Vortex Shedding Inside a Baffled Air Duct

Science.gov (United States)

Davis, Philip; Kenny, R. Jeremy

2010-01-01

Common in the operation of both segmented and un-segmented large solid rocket motors is the occurrence of vortex shedding within the motor chamber. A portion of the energy within a shed vortex is converted to acoustic energy, potentially driving the longitudinal acoustic modes of the motor in a quasi-discrete fashion. This vortex shedding-acoustic mode excitation event occurs for every Reusable Solid Rocket Motor (RSRM) operation, giving rise to subsequent axial thrust oscillations. In order to better understand this vortex shedding/acoustic mode excitation phenomena, unsteady CFD simulations were run for both a test geometry and the full scale RSRM geometry. This paper covers the results from the subscale geometry runs, which were based on work focusing on the RSRM hydrodynamics. Unsteady CFD simulation parameters, including boundary conditions and post-processing returns, are reviewed. The results were further post-processed to identify active acoustic modes and vortex shedding characteristics. Probable locations for acoustic energy generation, and subsequent acoustic mode excitation, are discussed.

Goodbye, solar shed; Pfiat di, Solarstadl

Energy Technology Data Exchange (ETDEWEB)

Diermann, Ralph

2012-07-01

In southern Germany, farmers and conservationalists are fighting over new sheds equipped with photovoltaic roofs. The impending amendment of the EEG is expected to solve the conflict. The losers of the game will be the farmers as reimbursement for solar roofs on sheds will be lowered.

Risk assessment modelling of fecal shedding caused by extended-spectrum cephalosporin-resistant Escherichia coli transmitted through waste milk fed to dairy pre-weaned calves.

Science.gov (United States)

Awosile, Babafela B; Smith, Ben A

2017-12-01

Waste milk feeding is a common practice in dairy operations. Regardless of the benefits of this practice to the dairy farmers, concerns from the potential dissemination of antimicrobial-resistant bacteria through the gut and subsequent shedding by calves into the environment are increasing. In this study, we employed Monte Carlo simulation to assess the risk of shedding extended-spectrum cephalosporin-resistant Escherichia coli (ESC-R E. coli) caused by waste milk feeding in pre-weaned calves using an exponential dose-response model fit to data for E. coli O157:H7 in cattle. Data from pertinent studies were included in our model to predict the risk of shedding. The median (5th and 95th percentiles) for the daily risk of shedding ESC-R E. coli by calves fed only contaminated waste milk was predicted to be 2.9 × 10 -3 (2.1 × 10 -3 , 3.7 × 10 -3 ), representing a median daily risk of 29 out of 10,000 calves shedding ESC-R E. coli due to exclusive feeding of waste milk containing ESC-R E. coli. This median value was reduced by 94% when accounting for the proportion of waste milk that does not contain ESC-R E. coli. The overall risk of shedding ESC-R E. coli through the pre-weaning period for farms that feed waste milk to calves was 5.7 × 10 -3 (2.4 × 10 -3 , 1.1 × 10 -2 ), representing 57 out of 10,000 calves. When accounting for the proportion of farms that do not feed waste milk, the pre-weaning period risk was reduced by 23%. By varying the prevalence of ESC-R E. coli in waste milk using values of 3, 1.5, and 1%, the daily risk of shedding decreased by factors of 50, 65, and 82%, respectively, which supports the reduction of contamination or discontinuation of feeding waste milk containing ESC-R E. coli as major mitigation measures to reduce the risk of shedding caused by ingestion of resistant bacteria. It is anticipated that the effects of antimicrobial residues in waste milk, which was not considered herein due to lack of data, would further increase risks

Spectroscopic and thermal characterization of alternative model biomembranes from shed skins of Bothrops jararaca and Spilotis pullatus

Directory of Open Access Journals (Sweden)

André Rolim Baby

2009-09-01

Full Text Available Recently, there has been an interest in the use of shed snake skin as alternative model biomembrane for human stratum corneum. This research work presented as objective the qualitative characterization of alternative model biomembranes from Bothrops jararaca and Spilotis pullatus by FT-Raman, PAS-FTIR and DSC. The employed biophysical techniques permitted the characterization of the biomembranes from shed snake skin of B. jararaca and S. pullatus by the identification of vibrational frequencies and endothermic transitions that are similar to those of the human stratum corneum.Existe atualmente interesse no uso da muda de pele de cobra como modelos alternativos de biomembranas da pele humana. O presente trabalho apresentou como objetivo a caracterização qualitativa de modelos alternativos de biomembranas provenientes de mudas de pele de cobra da Bothrops jararaca e Spilotis pullatus por espectroscopia Raman (FT-Raman, espectroscopia fotoacústica no infravermelho (PAS-FTIR e calorimetria exploratória diferencial (DSC. As técnicas biofísicas FT-Raman, PAS-FTIR e DSC permitiram caracterizar qualitativamente os modelos alternativos de biomembranas provenientes das mudas de pele de cobra da B. jararaca e S. pullatus e identificar freqüências vibracionais e transições endotérmicas similares ao estrato córneo humano.

CRISP. Intelligent load shedding. Deliverable 1.5

International Nuclear Information System (INIS)

Gajic, Z.; Karlsson, D.; Ullah, N.R.; Okuboye, S.; Andrieu, C.; Carlsson, P.

2005-08-01

Load shedding has been used to mitigate the consequences of large disturbances in electric power systems, since the beginning of the electrification era. The way to execute the load shedding, i.e. open a circuit breaker, has hardly developed at all for a 100-year period. The modern society dependence on reliable electricity supply is continuously increasing. This means that the consequences of traditional load shedding are not acceptable. In the meantime computer and communication technology has developed tremendously. There is also a trend to use more and more intelligent control and less hardware, such as lines and generators, to provide the required level of reliability for the electric supply. Especially in power systems, and parts of power systems, comprising distributed generation, there seems to be a great potential to improve the overall cost/benefit-ratio for the desired level of reliability, by the use of intelligent load shedding. Intelligent load shedding is a means to improve power system stability, by providing an adapted load control along the distribution network, in situations where the power system otherwise would go unstable. The work with intelligent load shedding in this work package results in various technical principles of dedicated algorithms. These algorithms intend to bring a support tool for the operating system during critical situations. The main aspects are evaluating the right amount and location of power response for a given disturbance, and evaluating the right time response expected in order to comply with an acceptable stability recover. This time response is a main object in order to define appropriate ICT network enabling such a reliable implementation. A main problem of the intelligent load shedding is how to choose load to shed conveniently and quickly. There is a technical problem of finding the right level and location of the load to shed, and also an economical problem of giving incentives in order to have enough remote

Alberi Validates New Theory, Sheds Light on Semiconductors | News | NREL

Science.gov (United States)

(cadmium telluride), and GaN (gallium nitride), which are used for cell phones, solar panels, and LED suppressing defects with light, which may allow higher efficiencies in solar panels, greater lifespan for LED

Overshoot effects of electron on efficiency droop in InGaN/GaN MQW light-emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Huang, Yang; Liu, Zhiqiang, E-mail: lzq@semi.ac.cn, E-mail: spring@semi.ac.cn; Yi, Xiaoyan, E-mail: lzq@semi.ac.cn, E-mail: spring@semi.ac.cn; Guo, Yao; Wu, Shaoteng; Yuan, Guodong; Wang, JunXi; Wang, Guohong; Li, Jinmin [R& D Center for Semiconductor Lighting, Chinese Academy of Sciences, Beijing 100083 (China); State Key Laboratory of Solid State Lighting, Beijing 100083 (China); Beijing Engineering Research Center for the 3rd Generation Semiconductor Materials and Application, Beijing 100083 (China)

2016-04-15

To evaluate electron leakage in InGaN/GaN multiple quantum well (MQW) light emitting diodes (LEDs), analytic models of ballistic and quasi-ballistic transport are developed. With this model, the impact of critical variables effecting electron leakage, including the electron blocking layer (EBL), structure of multiple quantum wells (MQWs), polarization field, and temperature are explored. The simulated results based on this model shed light on previously reported experimental observations and provide basic criteria for suppressing electron leakage, advancing the design of InGaN/GaN LEDs.

Role of quantum correlations in light-matter quantum heat engines

Science.gov (United States)

Barrios, G. Alvarado; Albarrán-Arriagada, F.; Cárdenas-López, F. A.; Romero, G.; Retamal, J. C.

2017-11-01

We study a quantum Otto engine embedding a working substance composed of a two-level system interacting with a harmonic mode. The physical properties of the substance are described by a generalized quantum Rabi model arising in superconducting circuit realizations. We show that light-matter quantum correlation reduction during the hot bath stage and adiabatic stages act as an indicator for enhanced work extraction and efficiency, respectively. Also, we demonstrate that the anharmonic spectrum of the working substance has a direct impact on the transition from heat engine into refrigerator as the light-matter coupling is increased. These results shed light on the search for optimal conditions in the performance of quantum heat engines.

Model Tests of Under Frequency Load Shedding (UFLS for Connected Systems of Continental Europe

Directory of Open Access Journals (Sweden)

Marek Głaz

2016-09-01

Full Text Available The task force set up by working group System Protection and Dynamics within ENTSO-E model tests of Under Frequency Load Shedding (UFLS for connected systems of continental Europe were carried out. Over 360 simulation scenarios were performed including 16 strategies UFLS, 2 variants of load, 6 types of contingency, with and without considering the impact of dispersed generation. On the basis of calculation results conditions for improving the effectiveness of the UFLS were specified,, including recommended changes of UFLS settings, necessary to achieve this aim. The following report contains a summary description of the test method together with the presentation of selected results of summary calculations and conclusions of the study.

Light Higgs and vector-like quarks without prejudice

Science.gov (United States)

Fajfer, Svjetlana; Greljo, Admir; Kamenik, Jernej F.; Mustać, Ivana

2013-07-01

Light vector-like quarks with non-renormalizable couplings to the Higgs are a common feature of models trying to address the electroweak (EW) hierarchy problem by treating the Higgs as a pseudo-goldstone boson of a global (approximate) symmetry. We systematically investigate the implications of the leading dimension five operators on Higgs phenomenology in presence of dynamical up- and down-type weak singlet as well as weak doublet vector-like quarks. After taking into account constraints from precision EW and flavour observables we show that contrary to the renormalizable models, significant modifications of Higgs properties are still possible and could shed light on the role of vector-like quarks in solutions to the EW hierarchy problem. We also briefly discuss implications of higher dimensional operators for direct vector-like quark searches at the LHC.

Depression, Anxiety, and Stress Symptoms in Menopausal Arab Women: Shedding More Light on a Complex Relationship.

Science.gov (United States)

Bener, A; Saleh, N M; Bakir, A; Bhugra, D

2016-01-01

The association between depression, anxiety, and stress among Arab menopause and postmenopausal women have been explored in detailed. The objective of this study was to determine the correlation between depression, anxiety, and stress in menopausal and postmenopausal women and shedding more light on a complex relationship. A cross-sectional descriptive study was used to generate menopause symptoms experienced by Arabian women at the primary health care centers in Qatar. A representative sample of 1468 women aged 45-65 years were approached during July 2012 and May 2014 and 1101 women agreed to participate (75.0%) and responded to the study. Depression, anxiety, and stress were measured using the Depression Anxiety Stress Scales 21. Data on body mass index (BMI), clinical and other parameters were used. Univariate, multivariate, and matrix correlation analysis were performed for statistical analysis. A total of 1101 women agreed to participate after informed consent was obtained. The mean age and standard deviation (SD) of the menopausal age were 49.55 (3.12), the mean and SD of postmenopausal age was 58.08 (3.26) ( P stress among menopause and postmenopause. The multivariate regression analyses revealed that age in years, diastolic BP, consanguinity, regular exercise were a predictor for depression. Meanwhile, diastolic BP, occupation, and physical activity considered the main risk factors for anxiety. Furthermore, age in years, occupation, and sheesha smoking habits were considered as the main risk factors associated with stress. A large number of factors were associated with experiencing menopausal and psycho-social problems and which had negative effects on the quality of life among Arabian women. Depression, anxiety, and stress should be considered as important risk factors for osteoporosis.

Mathematical Modeling Predicts that Increased HSV-2 Shedding in HIV-1 Infected Persons Is Due to Poor Immunologic Control in Ganglia and Genital Mucosa.

Directory of Open Access Journals (Sweden)

Joshua T Schiffer

Full Text Available A signature feature of HIV infection is poor control of herpes virus infections, which reactivate from latency and cause opportunistic infections. While the general mechanism underlying this observation is deficient CD4+T-cell function, it is unknown whether increased severity of herpes virus infections is due primarily to poor immune control in latent or lytic sites of infection, or whether CD4+ immunodeficiency leads to more critical downstream deficits in humoral or cell-mediated immunologic responses. Here we compare genital shedding patterns of herpes simplex virus-2 (HSV-2 in 98 HIV infected and 98 HIV uninfected men matched on length of infection, HSV-1 serostatus and nationality. We demonstrate that high copy HSV-2 shedding is more frequent in HIV positive men, particularly in participants with CD4+ T-cell count <200/μL. Genital shedding is more frequent due to higher rate of shedding episodes, as well as a higher proportion of prolonged shedding episodes. Peak episode viral load was not found to differ between HIV infected and uninfected participants regardless of CD4+ T-cell count. We simulate a mathematical model which recapitulates these findings and identifies that rate of HSV-2 release from neural tissue increases, duration of mucosal cytolytic immune protection decreases, and cell-free viral lifespan increases in HIV infected participants. These results suggest that increased HSV-2 shedding in HIV infected persons may be caused by impaired immune function in both latent and lytic tissue compartments, with deficits in clearance of HSV-2 infected cells and extracellular virus.

Improved Load Shedding Scheme considering Distributed Generation

DEFF Research Database (Denmark)

Das, Kaushik; Nitsas, Antonios; Altin, Müfit

2017-01-01

With high penetration of distributed generation (DG), the conventional under-frequency load shedding (UFLS) face many challenges and may not perform as expected. This article proposes new UFLS schemes, which are designed to overcome the shortcomings of traditional load shedding scheme...

Shedding genomic light on Aristotle's lantern.

Science.gov (United States)

Sodergren, Erica; Shen, Yufeng; Song, Xingzhi; Zhang, Lan; Gibbs, Richard A; Weinstock, George M

2006-12-01

Sea urchins have proved fascinating to biologists since the time of Aristotle who compared the appearance of their bony mouth structure to a lantern in The History of Animals. Throughout modern times it has been a model system for research in developmental biology. Now, the genome of the sea urchin Strongylocentrotus purpuratus is the first echinoderm genome to be sequenced. A high quality draft sequence assembly was produced using the Atlas assembler to combine whole genome shotgun sequences with sequences from a collection of BACs selected to form a minimal tiling path along the genome. A formidable challenge was presented by the high degree of heterozygosity between the two haplotypes of the selected male representative of this marine organism. This was overcome by use of the BAC tiling path backbone, in which each BAC represents a single haplotype, as well as by improvements in the Atlas software. Another innovation introduced in this project was the sequencing of pools of tiling path BACs rather than individual BAC sequencing. The Clone-Array Pooled Shotgun Strategy greatly reduced the cost and time devoted to preparing shotgun libraries from BAC clones. The genome sequence was analyzed with several gene prediction methods to produce a comprehensive gene list that was then manually refined and annotated by a volunteer team of sea urchin experts. This latter annotation community edited over 9000 gene models and uncovered many unexpected aspects of the sea urchin genetic content impacting transcriptional regulation, immunology, sensory perception, and an organism's development. Analysis of the basic deuterostome genetic complement supports the sea urchin's role as a model system for deuterostome and, by extension, chordate development.

Veje ind og ud af hjemløshed

DEFF Research Database (Denmark)

Benjaminsen, Lars; Enemark, Morten Holm

Hjemløsheden i Danmark har været stigende i de seneste år. Denne rapport beskriver forløbene op mod hjemløshed, vejene gennem hjemløshed og chancerne for at komme ud af hjemløshed igen. På baggrund af data fra hjemløsetællingerne og fra landets herberger (§ 110-boformer) i perioden 2009-2015 anal...

Birds shed RNA-viruses according to the pareto principle.

Directory of Open Access Journals (Sweden)

Mark D Jankowski

Full Text Available A major challenge in disease ecology is to understand the role of individual variation of infection load on disease transmission dynamics and how this influences the evolution of resistance or tolerance mechanisms. Such information will improve our capacity to understand, predict, and mitigate pathogen-associated disease in all organisms. In many host-pathogen systems, particularly macroparasites and sexually transmitted diseases, it has been found that approximately 20% of the population is responsible for approximately 80% of the transmission events. Although host contact rates can account for some of this pattern, pathogen transmission dynamics also depend upon host infectiousness, an area that has received relatively little attention. Therefore, we conducted a meta-analysis of pathogen shedding rates of 24 host (avian - pathogen (RNA-virus studies, including 17 bird species and five important zoonotic viruses. We determined that viral count data followed the Weibull distribution, the mean Gini coefficient (an index of inequality was 0.687 (0.036 SEM, and that 22.0% (0.90 SEM of the birds shed 80% of the virus across all studies, suggesting an adherence of viral shedding counts to the Pareto Principle. The relative position of a bird in a distribution of viral counts was affected by factors extrinsic to the host, such as exposure to corticosterone and to a lesser extent reduced food availability, but not to intrinsic host factors including age, sex, and migratory status. These data provide a quantitative view of heterogeneous virus shedding in birds that may be used to better parameterize epidemiological models and understand transmission dynamics.

Birds shed RNA-viruses according to the pareto principle.

Science.gov (United States)

Jankowski, Mark D; Williams, Christopher J; Fair, Jeanne M; Owen, Jennifer C

2013-01-01

A major challenge in disease ecology is to understand the role of individual variation of infection load on disease transmission dynamics and how this influences the evolution of resistance or tolerance mechanisms. Such information will improve our capacity to understand, predict, and mitigate pathogen-associated disease in all organisms. In many host-pathogen systems, particularly macroparasites and sexually transmitted diseases, it has been found that approximately 20% of the population is responsible for approximately 80% of the transmission events. Although host contact rates can account for some of this pattern, pathogen transmission dynamics also depend upon host infectiousness, an area that has received relatively little attention. Therefore, we conducted a meta-analysis of pathogen shedding rates of 24 host (avian) - pathogen (RNA-virus) studies, including 17 bird species and five important zoonotic viruses. We determined that viral count data followed the Weibull distribution, the mean Gini coefficient (an index of inequality) was 0.687 (0.036 SEM), and that 22.0% (0.90 SEM) of the birds shed 80% of the virus across all studies, suggesting an adherence of viral shedding counts to the Pareto Principle. The relative position of a bird in a distribution of viral counts was affected by factors extrinsic to the host, such as exposure to corticosterone and to a lesser extent reduced food availability, but not to intrinsic host factors including age, sex, and migratory status. These data provide a quantitative view of heterogeneous virus shedding in birds that may be used to better parameterize epidemiological models and understand transmission dynamics.

New perspectives to the enterotoxigenic E. coli F4 porcine infection model: Susceptibility genotypes in relation to performance, diarrhoea and bacterial shedding.

Science.gov (United States)

Roubos-van den Hil, Petra J; Litjens, Ralph; Oudshoorn, Anna-Katharina; Resink, Jan Willem; Smits, Coen H M

2017-04-01

Enterotoxigenic E. coli (ETEC), causing post-weaning diarrhoea, is a major problem in weaned piglets. Individual animal responses to ETEC infection show high variability in animal experiments. Two studies were designed to optimize the ETEC F4ac infection model in piglets by combining the genotype susceptibility with performance, diarrhoea incidence and bacterial shedding. The studies were performed with respectively 120 and 80 male piglets that were tested for susceptibility or resistance towards ETEC O149:F4ac by a DNA marker based test. Three different genotypes were observed; resistant (RR), susceptible heterozygote (RS) and susceptible homozygote (SS). Piglets, were orally infected with an inoculum suspension (containing 1.5E8 CFU/ml ETEC F4ac) at day 0, 1 and 2 of the study. Performance, diarrhoea incidence and bacterial shedding were followed for 21days. In the first week after challenge a difference in average daily gain was observed between resistant and susceptible piglets in both studies. For the complete study period no significant differences were observed. Diarrhoea incidence was significantly higher in susceptible pigs compared to the resistant pigs in the first week after challenge. Bacterial shedding was much higher in the susceptible pigs and ETEC excretion lasted longer. ETEC was hardly detected in the faecal material of the resistant pigs. In conclusion, susceptible pigs showed higher diarrhoea incidence and higher numbers of faecal ETEC shedding in the first week after challenge compared to resistant pigs. The DNA marker based test can be used to select pigs that are susceptible for ETEC for inclusion in ETEC infection model, resulting in less animals needed to perform infection studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Phthalate SHEDS-HT runs

Data.gov (United States)

U.S. Environmental Protection Agency — Inputs and outputs for SHEDS-HT runs of DiNP, DEHP, DBP. This dataset is associated with the following publication: Moreau, M., J. Leonard, K. Phillips, J. Campbell,...

The International Globe at Night Citizen-Science Campaign: Shedding Light on Light Pollution

Science.gov (United States)

Walker, C. E.; Pompea, S. M.

2013-12-01

For 8 years now, the Globe at Night campaign has invited citizen-scientists worldwide to measure and record the brightness of their night sky by hunting for the faintest stars in a particular constellation. Students for science projects and scientists for research use the data to monitor levels of brightness or 'light pollution' around the world. They also use the Globe at Night data to understand light pollution's effects on energy consumption, plants, wildlife and human health, as well as our ability to enjoy a starry night sky. The dates of the campaign for 2014 have been extended to every month during the year. Ten days each month (when the Moon is not up between 8pm and 10pm) are the recommended times to take measurements for the campaign. However, one can participate at other times and dates, as long as the Moon is not in the night sky and it is more than an hour after sunset or more than an hour before sunrise. New in 2014 will be an Android app that will allow you to input visual measurements anytime the Moon is not up. Also possibly included will be an iPhone app that will take sky brightness measurements. The campaign dates and the 5 easy steps to participating in the campaign are listed at www.globeatnight.org. You do not need to register. Once on the report page, you enter your location, date and time (automatic for a smart device). You find the constellation of the month in the night sky. (Help is on the website.) Then you choose which chart looks most like what you see toward the constellation. Choose the icon for how clear or cloudy it is and hit the submit button and you are done! The fifth step is returning later to the website to compare your observations on the world map to others from around the globe. Included on the Globe at Night website are many helpful resources and tools from finding the constellations used in the campaign, to understanding concepts like light pollution, to games that test your expertise in choosing 'limiting magnitudes

Remote fluorescent penetrant system sheds new light on cracking

International Nuclear Information System (INIS)

Anon.

1993-01-01

A remotely operated fluorescent penetrant inspection system developed in Sweden has successfully identified very small cracks -less than 2mm in length and less than 0.2mm in depth. The method, which is being patented, is applicable to all sizes of tubing, as well as other types of flat or curved surfaces. The system consists of a specially designed probe attached to a flexible hose. The probe is positioned by a remotely operated pusher-puller, which can be attached to any kind of robot. The pusher-puller is equipped with electrical motors and encoders for exact positioning at any given location. The hose is attached to a pump and valve unit remote from the item under test, located in the same area as the control equipment for the pusher-puller and the robot. Once the probe has been positioned in the area of interest, it is able to apply fluorescent penetrant test fluid remotely to the surface under test, using a system of inflatable seals. A fluorescent print is made on the probe head, which is then removed from the tube and another probe head fitted for testing of the next tube. Testing takes about 10 minutes per tube. To take measurements, a photograph of the probe head can be taken under ultraviolet light. Manual transfer of the fluorescent print under ultraviolet light to a transparent plastic sheet, temporarily wrapped around the probe head, is also done. The plastic sheet is then unfolded and copied in a normal photocopying machine, and a permanent record thus created. (author)

Counter and Complicit Masculine Discourse Among Men's Shed Members.

Science.gov (United States)

Mackenzie, Corey S; Roger, Kerstin; Robertson, Steve; Oliffe, John L; Nurmi, Mary Anne; Urquhart, James

2017-07-01

Men's Sheds is a growing international movement aimed at providing men with places and activities that facilitate social connectedness. Despite Men's Sheds' focus on males, little attention has been paid to masculinities within the specific context of these settings. The current study used a gender relations framework to explore the ways in which attendees discussed Men's Sheds, with particular attention to discussions that were complicit and counter to traditional, hegemonic views of masculinity, and diverse positions in between these binaries. The data consisted of transcripts and field notes from four focus groups comprising mostly older, White, retired male members of a Canadian shed ( N = 22). The analysis revealed three overall themes: (1) focus on work, (2) independence, and (3) need for male-focused spaces. These themes and associated subthemes suggest that shed members ascribe to dominant masculine values and ideals, but also support more fluid and flexible views of masculinity. Implications are discussed for how working with an array of masculinities within the Men's Sheds movement will be helpful with respect to their future growth in Canada and internationally.

Numerical Simulations of Vortex Shedding in Hydraulic Turbines

Science.gov (United States)

Dorney, Daniel; Marcu, Bogdan

2004-01-01

Turbomachines for rocket propulsion applications operate with many different working fluids and flow conditions. Oxidizer boost turbines often operate in liquid oxygen, resulting in an incompressible flow field. Vortex shedding from airfoils in this flow environment can have adverse effects on both turbine performance and durability. In this study the effects of vortex shedding in a low-pressure oxidizer turbine are investigated. Benchmark results are also presented for vortex shedding behind a circular cylinder. The predicted results are compared with available experimental data.

Educational complex of light-colored modeling of urban environment

Directory of Open Access Journals (Sweden)

Karpenko Vladimir E.

2018-01-01

Full Text Available Mechanisms, methodological tools and structure of a training complex of light-colored modeling of the urban environment are developed in this paper. The following results of the practical work of students are presented: light composition and installation, media facades, lighting of building facades, city streets and embankment. As a result of modeling, the structure of the light form is determined. Light-transmitting materials and causing characteristic optical illusions, light-visual and light-dynamic effects (video-dynamics and photostatics, basic compositional techniques of light form are revealed. The main elements of the light installation are studied, including a light projection, an electronic device, interactivity and relationality of the installation, and the mechanical device which becomes a part of the installation composition. The meaning of modern media facade technology is the transformation of external building structures and their facades into a changing information cover, into a media content translator using LED technology. Light tectonics and the light rhythm of the plastics of the architectural object are built up through point and local illumination, modeling of the urban ensemble assumes the structural interaction of several light building models with special light-composition techniques. When modeling the social and pedestrian environment, the lighting parameters depend on the scale of the chosen space and are adapted taking into account the visual perception of the pedestrian, and the atmospheric effects of comfort and safety of the environment are achieved with the help of special light compositional techniques. With the aim of realizing the tasks of light modeling, a methodology has been created, including the mechanisms of models, variability and complementarity. The perspectives of light modeling in the context of structural elements of the city, neuropsychology, wireless and bioluminescence technologies are proposed

Load shedding scheme in the south/southeastern interconnected system

Energy Technology Data Exchange (ETDEWEB)

Vieira Filho, Xisto; Couri, J J.G.; Gomes, P; Almeida, P C [ELETROBRAS, Rio de Janeiro, RJ (Brazil)

1988-12-31

This paper presents some characteristics of the Brazilian interconnected system and discusses the load shedding scheme in its different stages considering the beginning of operation of the Itaipu power plant. The present situation of the South and Southeastern load shedding scheme combination is also commented. Finally, the interconnected system evolution and the effects on the load shedding schemes are discussed. 4 refs., 5 figs., 2 tabs.

Adjoint sensitivity studies of loop current and eddy shedding in the Gulf of Mexico

KAUST Repository

Gopalakrishnan, Ganesh; Cornuelle, Bruce D.; Hoteit, Ibrahim

2013-01-01

Adjoint model sensitivity analyses were applied for the loop current (LC) and its eddy shedding in the Gulf of Mexico (GoM) using the MIT general circulation model (MITgcm). The circulation in the GoM is mainly driven by the energetic LC and subsequent LC eddy separation. In order to understand which ocean regions and features control the evolution of the LC, including anticyclonic warm-core eddy shedding in the GoM, forward and adjoint sensitivities with respect to previous model state and atmospheric forcing were computed using the MITgcm and its adjoint. Since the validity of the adjoint model sensitivities depends on the capability of the forward model to simulate the real LC system and the eddy shedding processes, a 5 year (2004–2008) forward model simulation was performed for the GoM using realistic atmospheric forcing, initial, and boundary conditions. This forward model simulation was compared to satellite measurements of sea-surface height (SSH) and sea-surface temperature (SST), and observed transport variability. Despite realistic mean state, standard deviations, and LC eddy shedding period, the simulated LC extension shows less variability and more regularity than the observations. However, the model is suitable for studying the LC system and can be utilized for examining the ocean influences leading to a simple, and hopefully generic LC eddy separation in the GoM. The adjoint sensitivities of the LC show influences from the Yucatan Channel (YC) flow and Loop Current Frontal Eddy (LCFE) on both LC extension and eddy separation, as suggested by earlier work. Some of the processes that control LC extension after eddy separation differ from those controlling eddy shedding, but include YC through-flow. The sensitivity remains stable for more than 30 days and moves generally upstream, entering the Caribbean Sea. The sensitivities of the LC for SST generally remain closer to the surface and move at speeds consistent with advection by the high-speed core of

Adjoint sensitivity studies of loop current and eddy shedding in the Gulf of Mexico

KAUST Repository

Gopalakrishnan, Ganesh

2013-07-01

Adjoint model sensitivity analyses were applied for the loop current (LC) and its eddy shedding in the Gulf of Mexico (GoM) using the MIT general circulation model (MITgcm). The circulation in the GoM is mainly driven by the energetic LC and subsequent LC eddy separation. In order to understand which ocean regions and features control the evolution of the LC, including anticyclonic warm-core eddy shedding in the GoM, forward and adjoint sensitivities with respect to previous model state and atmospheric forcing were computed using the MITgcm and its adjoint. Since the validity of the adjoint model sensitivities depends on the capability of the forward model to simulate the real LC system and the eddy shedding processes, a 5 year (2004–2008) forward model simulation was performed for the GoM using realistic atmospheric forcing, initial, and boundary conditions. This forward model simulation was compared to satellite measurements of sea-surface height (SSH) and sea-surface temperature (SST), and observed transport variability. Despite realistic mean state, standard deviations, and LC eddy shedding period, the simulated LC extension shows less variability and more regularity than the observations. However, the model is suitable for studying the LC system and can be utilized for examining the ocean influences leading to a simple, and hopefully generic LC eddy separation in the GoM. The adjoint sensitivities of the LC show influences from the Yucatan Channel (YC) flow and Loop Current Frontal Eddy (LCFE) on both LC extension and eddy separation, as suggested by earlier work. Some of the processes that control LC extension after eddy separation differ from those controlling eddy shedding, but include YC through-flow. The sensitivity remains stable for more than 30 days and moves generally upstream, entering the Caribbean Sea. The sensitivities of the LC for SST generally remain closer to the surface and move at speeds consistent with advection by the high-speed core of

Cardiorespiratory effects of venous lipid micro embolization in an experimental model of mediastinal shed blood reinfusion

Directory of Open Access Journals (Sweden)

Dencker Magnus

2009-09-01

Full Text Available Abstract Background Retransfusion of the patient's own blood during surgery is used to reduce the need for allogenic blood transfusion. It has however been found that this blood contains lipid particles, which form emboli in different organs if the blood is retransfused on the arterial side. In this study, we tested whether retransfusion of blood containing lipid micro-particles on the venous side in a porcine model will give hemodynamic effects. Methods Seven adult pigs were used. A shed blood surrogate containing 400 ml diluted blood and 5 ml radioactive triolein was produced to generate a lipid embolic load. The shed blood surrogate was rapidly ( Results A more than 30-fold increase in pulmonary vascular resistance was observed, with subsequent increase in pulmonary artery pressure, and decrease in cardiac output and arterial pressure. This response was transient, but was followed by a smaller, persistent increase in pulmonary vascular resistance. Only a small portion of the infused triolein passed the lungs, and only a small fraction could be recirculated by increasing cardiac output and pulmonary pressure. Conclusion Infusion of blood containing lipid micro-emboli on the venous side leads to acute, severe hemodynamic responses that can be life threatening. Lipid particles will be trapped in the lungs, leading to persistent effects on the pulmonary vascular resistance.

Light regimes in Populus plantations using the Voxel-based Light Interception Model

NARCIS (Netherlands)

Van der Zande, D.; Dieussart, K.; Stuckens, J.; Verstraeten, W.W.; Coppin, P.

2011-01-01

Three-dimensional light interception by three uniform Populus canopies was studied using the Voxel-based Light Interception Model (VLIM) in combination with ground-based Light Detection and Ranging (LiDAR) measurements. As the VLIM was developed and validated in a virtual environment to ensure

Nanoscale interfacial defect shedding in a growing nematic droplet.

Science.gov (United States)

Gurevich, Sebastian; Provatas, Nikolas; Rey, Alejandro

2017-08-01

Interfacial defect shedding is the most recent known mechanism for defect formation in a thermally driven isotropic-to-nematic phase transition. It manifests in nematic-isotropic interfaces going through an anchoring switch. Numerical computations in planar geometry established that a growing nematic droplet can undergo interfacial defect shedding, nucleating interfacial defect structures that shed into the bulk as +1/2 point defects. By extending the study of interfacial defect shedding in a growing nematic droplet to larger length and time scales, and to three dimensions, we unveil an oscillatory growth mode involving shape and anchoring transitions that results in a controllable regular distributions of point defects in planar geometry, and complex structures of disclination lines in three dimensions.

Parity- and time-reversal-violating moments of light nuclei

Energy Technology Data Exchange (ETDEWEB)

Vries, Jordy de, E-mail: devries@kvi.nl [KVI, theory group (Netherlands)

2013-03-15

I present the calculation of parity- and time-reversal-violating moments of the nucleon and light nuclei, originating from the QCD {theta}-bar term and effective dimension-six operators. By applying chiral effective field theory these calculations are performed in a unified framework. I argue that measurements of a few light-nuclear electric dipole moments would shed light on the mechanism of parity and time-reversal violation.

Mucosal HSV-2 specific CD8+ T-cells represent containment of prior viral shedding rather than a correlate of future protection

Directory of Open Access Journals (Sweden)

Joshua Tisdell Schiffer

2013-07-01

Full Text Available It is largely unknown why certain infected hosts shed Herpes Simplex Virus-2 (HSV-2 more frequently and have more severe disease manifestations than others. One idea is that different density or functional capacity of tissue resident effector memory CD8+ T-cells between infected persons may explain phenotypic variability. To generate hypotheses for contrasting shedding patterns in different infected hosts, a spatial mathematical model was employed to evaluate the effects of variability in tissue resident effector memory CD8+ T-cell response, and HSV-2 replication and spread, on viral shedding rate. Model simulations suggest that high levels of CD8+ T-cells in the mucosa do not necessarily indicate a protective phenotype but rather an effective response to recent shedding. Moreover, higher CD8+ T-cell expansion rate and lower viral replication rate, which correlate with better short-term control, may have only a minor impact on long term shedding rates. Breakthrough shedding occurs under all sets of model parameter assumptions, because CD8+ T-cell levels only surpass a protective threshold in a minority of genital tract mucosal micro-regions. If CD8+ T-cell levels are artificially increased using an immunotherapeutic approach, better control of shedding is predicted to occur for at least a year. These results highlight the complex co-dependent relationship between HSV-2 and tissue resident CD8+ lymphocytes during the course of natural infection.

Light extraction in planar light-emitting diode with nonuniform current injection: model and simulation.

Science.gov (United States)

Khmyrova, Irina; Watanabe, Norikazu; Kholopova, Julia; Kovalchuk, Anatoly; Shapoval, Sergei

2014-07-20

We develop an analytical and numerical model for performing simulation of light extraction through the planar output interface of the light-emitting diodes (LEDs) with nonuniform current injection. Spatial nonuniformity of injected current is a peculiar feature of the LEDs in which top metal electrode is patterned as a mesh in order to enhance the output power of light extracted through the top surface. Basic features of the model are the bi-plane computation domain, related to other areas of numerical grid (NG) cells in these two planes, representation of light-generating layer by an ensemble of point light sources, numerical "collection" of light photons from the area limited by acceptance circle and adjustment of NG-cell areas in the computation procedure by the angle-tuned aperture function. The developed model and procedure are used to simulate spatial distributions of the output optical power as well as the total output power at different mesh pitches. The proposed model and simulation strategy can be very efficient in evaluation of the output optical performance of LEDs with periodical or symmetrical configuration of the electrodes.

Student Modeling and Machine Learning

OpenAIRE

Sison , Raymund; Shimura , Masamichi

1998-01-01

After identifying essential student modeling issues and machine learning approaches, this paper examines how machine learning techniques have been used to automate the construction of student models as well as the background knowledge necessary for student modeling. In the process, the paper sheds light on the difficulty, suitability and potential of using machine learning for student modeling processes, and, to a lesser extent, the potential of using student modeling techniques in machine le...

Yukawa couplings and the nature of zero modes in the Skyrme model

International Nuclear Information System (INIS)

Kawarabayashi, K.

1989-01-01

Several issues related, directly or indirectly, to the Yukawa coupling in the Skyrme model are discussed. The authors try to shed a new light on the physical nature of the zero modes associated with translation (rotation) invariance of the model

Economic versus belief-based models: Shedding light on the adoption of novel green technologies

International Nuclear Information System (INIS)

Girod, Bastien; Mayer, Sebastian; Nägele, Florian

2017-01-01

Understanding the determinants for the adoption of novel green consumer technologies is important to effectively foster their diffusion. Energy and environmental science literature often takes an approach based on economic variables such as objectively measureable household and technology characteristics. Increasingly, also subjective variables based on personal belief are considered. On the basis of a survey about the intention to adopt an exemplary novel green consumer technology (intelligent thermostats), we contribute to the clarification of the explanatory power of these two approaches. We first compare the economic model to the belief-based model and second, investigate how beliefs about the green technology are influenced by personal environmental norms and innovativeness. Our evaluation shows that the belief-based model explains considerably higher variance in the intention to adopt. Thereby the perceived hedonic satisfaction, usefulness, habit and facilitating conditions reveal as key determinants. Moreover, environmental norms show lower impact than personal innovativeness. In the discussion we consolidate these findings and point to the risk of omitted variable bias when selectively including belief-based variables in adoption models. Our findings suggest that policies can effectively accelerate the early market diffusion of green consumer technologies by incentivizing retailers to introduce and market such technologies. - Highlights: • Adoption of a green consumer technology (energy-saving thermostats) is evaluated. • Subjective beliefs about the technology show higher impact than objective measures. • Key beliefs relate to pleasure, usefulness, habits and facilitating conditions. • Personal innovativeness is more relevant for adoption than environmental norms. • Isolated use of belief-based adoption determinants can lead to omitted variable bias.

Consequences of Spatial Antisymmetry on Light

Energy Technology Data Exchange (ETDEWEB)

Mascarenhas, Angelo; Fluegel, Brian

2016-12-21

Light propagation in two and three dimensional lattices for which the index of refraction exhibits spatial antisymmetry is investigated in the ray and photonic crystal regimes. In these regimes, all the two dimensional antisymmetry groups for which light fails to propagate are identified. In the ray-regime, it is observed that in tilings described by 7 of the 46 two dimensional antisymmetric groups, light is localized within a fundamental domain and does not propagate through the tiling, in contrast to the behavior in the other 39 groups. To understand the above phenomenon, a rule based on the number of anti-mirror planes passing through a single Bravais lattice point is derived. In the wave regime for photonic crystals, it is observed that there are no propagating eigensolutions for the same 7 tilings as above, whereas propagating solutions and energy pass band dispersion curves can be obtained for the other 39 groups. The reasons underlying this peculiar behavior are analyzed using the topological approach for modeling flow in dynamical billiards to shed light on the applicability of Bloch's theorem for these periodic antisymmetric lattices.

Neisseria gonorrhoeae co-infection exacerbates vaginal HIV shedding without affecting systemic viral loads in human CD34+ engrafted mice.

Directory of Open Access Journals (Sweden)

Stacey X Xu

Full Text Available HIV synergy with sexually transmitted co-infections is well-documented in the clinic. Co-infection with Neisseria gonorrhoeae in particular, increases genital HIV shedding and mucosal transmission. However, no animal model of co-infection currently exists to directly explore this relationship or to bridge the gap in understanding between clinical and in vitro studies of this interaction. This study aims to test the feasibility of using a humanized mouse model to overcome this barrier. Combining recent in vivo modelling advancements in both HIV and gonococcal research, we developed a co-infection model by engrafting immunodeficient NSG mice with human CD34+ hematopoietic stem cells to generate humanized mice that permit both systemic HIV infection and genital N. gonorrhoeae infection. Systemic plasma and vaginal lavage titres of HIV were measured in order to assess the impact of gonococcal challenge on viral plasma titres and genital shedding. Engrafted mice showed human CD45+ leukocyte repopulation in blood and mucosal tissues. Systemic HIV challenge resulted in 104-105 copies/mL of viral RNA in blood by week 4 post-infection, as well as vaginal shedding of virus. Subsequent gonococcal challenge resulted in unchanged plasma HIV levels but higher viral shedding in the genital tract, which reflects published clinical observations. Thus, human CD34+ stem cell-transplanted NSG mice represent an experimentally tractable animal model in which to study HIV shedding during gonococcal co-infection, allowing dissection of molecular and immunological interactions between these pathogens, and providing a platform to assess future therapeutics aimed at reducing HIV transmission.

Neisseria gonorrhoeae co-infection exacerbates vaginal HIV shedding without affecting systemic viral loads in human CD34+ engrafted mice.

Science.gov (United States)

Xu, Stacey X; Leontyev, Danila; Kaul, Rupert; Gray-Owen, Scott D

2018-01-01

HIV synergy with sexually transmitted co-infections is well-documented in the clinic. Co-infection with Neisseria gonorrhoeae in particular, increases genital HIV shedding and mucosal transmission. However, no animal model of co-infection currently exists to directly explore this relationship or to bridge the gap in understanding between clinical and in vitro studies of this interaction. This study aims to test the feasibility of using a humanized mouse model to overcome this barrier. Combining recent in vivo modelling advancements in both HIV and gonococcal research, we developed a co-infection model by engrafting immunodeficient NSG mice with human CD34+ hematopoietic stem cells to generate humanized mice that permit both systemic HIV infection and genital N. gonorrhoeae infection. Systemic plasma and vaginal lavage titres of HIV were measured in order to assess the impact of gonococcal challenge on viral plasma titres and genital shedding. Engrafted mice showed human CD45+ leukocyte repopulation in blood and mucosal tissues. Systemic HIV challenge resulted in 104-105 copies/mL of viral RNA in blood by week 4 post-infection, as well as vaginal shedding of virus. Subsequent gonococcal challenge resulted in unchanged plasma HIV levels but higher viral shedding in the genital tract, which reflects published clinical observations. Thus, human CD34+ stem cell-transplanted NSG mice represent an experimentally tractable animal model in which to study HIV shedding during gonococcal co-infection, allowing dissection of molecular and immunological interactions between these pathogens, and providing a platform to assess future therapeutics aimed at reducing HIV transmission.

Suppression of vortex shedding around a square cylinder using ...

Indian Academy of Sciences (India)

control of vortex shedding of square cylinders using blowing or suction. ... also showed complete suppression of vortex shedding if suction velocity falls between 0.40 .... equations such that mass balance (continuity) is satisfied simultaneously.

Light reflection models for computer graphics.

Science.gov (United States)

Greenberg, D P

1989-04-14

During the past 20 years, computer graphic techniques for simulating the reflection of light have progressed so that today images of photorealistic quality can be produced. Early algorithms considered direct lighting only, but global illumination phenomena with indirect lighting, surface interreflections, and shadows can now be modeled with ray tracing, radiosity, and Monte Carlo simulations. This article describes the historical development of computer graphic algorithms for light reflection and pictorially illustrates what will be commonly available in the near future.

Cell shedding from X-irradiated multicellular spheroids of human lung carcinomas

International Nuclear Information System (INIS)

Sakata, K.; Okada, S.; Suzuki, N.; Majima, H.

1991-01-01

We studied the effect of radiation on cell shedding from the surface of multicellular spheroids. Spheroids were produced from two human lung cell lines, one adenocarcinoma (LCT1) and the other small cell carcinoma (LCT2), by using a liquid overlay culture technique. The number of cells shed from both kinds of spheroids did not change significantly when they were irradiated. The number of clonogenic cells shed from both kinds of irradiated spheroids decreased sharply as the dose of irradiation increases. There were no significant differences in clonogenic cell shedding per spheroid between LCT1 and LCT2 spheroids. 400 μm spheroids were more radioresistant to inhibition of clonogenic cell shedding than 250 μm spheroids. Shed cells were more radiosensitive than speroid cells. In these experiments, we did not obtain any results indicating that radiation enchances metastasis. (orig.) [de

Shedding light on tree growth : ring analysis of juvenile tropical trees

NARCIS (Netherlands)

Soliz Gamboa, C.C.

2010-01-01

In the understory of tropical forests light is believed to be the main limiting growth factor for the newly established trees. Trees growing in shade of the understory may experience periods of slow radial growth. It is expected that gaps created by tree or branch fall will provoke tree growth

Herpes simplex virus-2 genital tract shedding is not predictable over months or years in infected persons.

Directory of Open Access Journals (Sweden)

Varsha Dhankani

2014-11-01

Full Text Available Herpes simplex virus-2 (HSV-2 is a chronic reactivating infection that leads to recurrent shedding episodes in the genital tract. A minority of episodes are prolonged, and associated with development of painful ulcers. However, currently, available tools poorly predict viral trajectories and timing of reactivations in infected individuals. We employed principal components analysis (PCA and singular value decomposition (SVD to interpret HSV-2 genital tract shedding time series data, as well as simulation output from a stochastic spatial mathematical model. Empirical and model-derived, time-series data gathered over >30 days consists of multiple complex episodes that could not be reduced to a manageable number of descriptive features with PCA and SVD. However, single HSV-2 shedding episodes, even those with prolonged duration and complex morphologies consisting of multiple erratic peaks, were consistently described using a maximum of four dominant features. Modeled and clinical episodes had equivalent distributions of dominant features, implying similar dynamics in real and simulated episodes. We applied linear discriminant analysis (LDA to simulation output and identified that local immune cell density at the viral reactivation site had a predictive effect on episode duration, though longer term shedding suggested chaotic dynamics and could not be predicted based on spatial patterns of immune cell density. These findings suggest that HSV-2 shedding patterns within an individual are impossible to predict over weeks or months, and that even highly complex single HSV-2 episodes can only be partially predicted based on spatial distribution of immune cell density.

Modeling the vacuolar storage of malate shed lights on pre- and post-harvest fruit acidity.

Science.gov (United States)

Etienne, Audrey; Génard, Michel; Lobit, Philippe; Bugaud, Christophe

2014-11-18

Malate is one of the most important organic acids in many fruits and its concentration plays a critical role in organoleptic properties. Several studies suggest that malate accumulation in fruit cells is controlled at the level of vacuolar storage. However, the regulation of vacuolar malate storage throughout fruit development, and the origins of the phenotypic variability of the malate concentration within fruit species remain to be clarified. In the present study, we adapted the mechanistic model of vacuolar storage proposed by Lobit et al. in order to study the accumulation of malate in pre and postharvest fruits. The main adaptation concerned the variation of the free energy of ATP hydrolysis during fruit development. Banana fruit was taken as a reference because it has the particularity of having separate growth and post-harvest ripening stages, during which malate concentration undergoes substantial changes. Moreover, the concentration of malate in banana pulp varies greatly among cultivars which make possible to use the model as a tool to analyze the genotypic variability. The model was calibrated and validated using data sets from three cultivars with contrasting malate accumulation, grown under different fruit loads and potassium supplies, and harvested at different stages. The model predicted the pre and post-harvest dynamics of malate concentration with fairly good accuracy for the three cultivars (mean RRMSE = 0.25-0.42). The sensitivity of the model to parameters and input variables was analyzed. According to the model, vacuolar composition, in particular potassium and organic acid concentrations, had an important effect on malate accumulation. The model suggested that rising temperatures depressed malate accumulation. The model also helped distinguish differences in malate concentration among the three cultivars and between the pre and post-harvest stages by highlighting the probable importance of proton pump activity and particularly of the free

Vortex Shedding in the Wake Induced by a Real Elephant Seal Whisker

Science.gov (United States)

Turk, Jodi; Omilion, Alexis; Zhang, Wei; Kim, Jeong-Jae; Kim, Jeong-Ju; Choi, Woo-Rak; Lee, Sang-Joon

2017-11-01

Biomimicry has been adopted to create innovative solutions in a vast range of applications. One such application is the design of seal-whisker-inspired flow sensors for autonomous underwater vehicles (AUVs). In dark, cramped, and unstable terrain AUVs are not able to maneuver using visual and sonar-based navigation. Hence, it is critical to use underwater flow sensors to accurately detect minute disturbances in the surroundings. Certain seal whiskers exhibit a unique undulating three-dimensional morphology that can reduce vortex induced vibrations (VIVs) if the major axis of the whisker cross-section is aligned to the inflow. This allows the seal to precisely track prey fish upstream using solely their whiskers. The current study aims to understand the effect of a real seal whisker's morphology on the vortex shedding behavior. Despite extensive studies of wake induced by scaled whisker-like models, the vortex shedding in the wake of a real seal whisker is not well understood. A series of experiments are conducted with a high-speed Particle Imaging Velocimetry (PIV) system in a water channel to examine the vortex shedding downstream from a smooth whisker and an undulating whisker at a Reynolds number of a few hundred. Results of the vortex shedding induced by real seal whiskers can provide insights on developing high-sensitivity underwater flow sensors for AUVs and other whisker-inspired structures.

Avian influenza shedding patterns in waterfowl: implications for surveillance, environmental transmission, and disease spread

Science.gov (United States)

Henaux, Viviane; Samuel, Michael D.

2011-01-01

Despite the recognized importance of fecal/oral transmission of low pathogenic avian influenza (LPAI) via contaminated wetlands, little is known about the length, quantity, or route of AI virus shed by wild waterfowl. We used published laboratory challenge studies to evaluate the length and quantity of low pathogenic (LP) and highly pathogenic (HP) virus shed via oral and cloacal routes by AI-infected ducks and geese, and how these factors might influence AI epidemiology and virus detection. We used survival analysis to estimate the duration of infection (from virus inoculation to the last day virus was shed) and nonlinear models to evaluate temporal patterns in virus shedding. We found higher mean virus titer and longer median infectious period for LPAI-infected ducks (10–11.5 days in oral and cloacal swabs) than HPAI-infected ducks (5 days) and geese (7.5 days). Based on the median bird infectious dose, we found that environmental contamination is two times higher for LPAI- than HPAI-infectious ducks, which implies that susceptible birds may have a higher probability of infection during LPAI than HPAI outbreaks. Less environmental contamination during the course of infection and previously documented shorter environmental persistence for HPAI than LPAI suggest that the environment is a less favorable reservoir for HPAI. The longer infectious period, higher virus titers, and subclinical infections with LPAI viruses favor the spread of these viruses by migratory birds in comparison to HPAI. Given the lack of detection of HPAI viruses through worldwide surveillance, we suggest monitoring for AI should aim at improving our understanding of AI dynamics (in particular, the role of the environment and immunity) using long-term comprehensive live bird, serologic, and environmental sampling at targeted areas. Our findings on LPAI and HPAI shedding patterns over time provide essential information to parameterize environmental transmission and virus spread in predictive

76 FR 66220 - Automatic Underfrequency Load Shedding and Load Shedding Plans Reliability Standards

Science.gov (United States)

2011-10-26

.... I. Background A. Underfrequency Load Shedding 4. An interconnected electric power system must... generation and load within an interconnected electric power system is shown in the frequency of the system.\\4... Reliability Standards for the Bulk-Power System, Order No. 693, FERC Stats. & Regs. ] 31,242, order on reh'g...

Periodic cavitation shedding in a cylindrical orifice

Energy Technology Data Exchange (ETDEWEB)

Stanley, C.; Barber, T.; Milton, B.; Rosengarten, G. [University of New South Wales, School of Mechanical and Manufacturing Engineering, Sydney (Australia)

2011-11-15

Cavitation structures in a large-scale (D = 8.25 mm), plain orifice style nozzle within a unique experimental rig are investigated using high-speed visualisation and digital image processing techniques. Refractive index matching with an acrylic nozzle is achieved using aqueous sodium iodide for the test fluid. Cavitation collapse length, unsteady shedding frequency and spray angles are measured for cavitation conditions from incipient to supercavitation for a range of Reynolds numbers, for a fixed L/D ratio of 4.85. Periodic cavitation shedding was shown to occur with frequencies between 500 and 2,000 Hz for conditions in which cavitation occupied less than 30% of the nozzle length. A discontinuity in collapse length was shown to occur once the cavitation exceeded this length, coinciding with a loss of periodic shedding. A mechanism for this behaviour is discussed. Peak spray angles of approximately {theta} {approx} 14 were recorded for supercavitation conditions indicating the positive influence of cavitation bubble collapse on the jet atomisation process. (orig.)

Modeling the Frequency of Cyclists’ Red-Light Running Behavior Using Bayesian PG Model and PLN Model

Directory of Open Access Journals (Sweden)

Yao Wu

2016-01-01

Full Text Available Red-light running behaviors of bicycles at signalized intersection lead to a large number of traffic conflicts and high collision potentials. The primary objective of this study is to model the cyclists’ red-light running frequency within the framework of Bayesian statistics. Data was collected at twenty-five approaches at seventeen signalized intersections. The Poisson-gamma (PG and Poisson-lognormal (PLN model were developed and compared. The models were validated using Bayesian p values based on posterior predictive checking indicators. It was found that the two models have a good fit of the observed cyclists’ red-light running frequency. Furthermore, the PLN model outperformed the PG model. The model estimated results showed that the amount of cyclists’ red-light running is significantly influenced by bicycle flow, conflict traffic flow, pedestrian signal type, vehicle speed, and e-bike rate. The validation result demonstrated the reliability of the PLN model. The research results can help transportation professionals to predict the expected amount of the cyclists’ red-light running and develop effective guidelines or policies to reduce red-light running frequency of bicycles at signalized intersections.

The Role of Collaborative Learning on Training and Development Practices within the Australian Men's Shed Movement: A Study of Five Men's Sheds

Science.gov (United States)

Cavanagh, Jillian; Southcombe, Amie; Bartram, Tim

2014-01-01

This study examines the role and impact of collaborative learning on training and development practices in Australian Men's Sheds. We use a case study approach, underpinned by Peters and Armstrong's theoretical framework of collaborative learning in adult education, to investigate five Men's Sheds. Semi-structured interviews were carried out with…

Bifidobacterium breve reduces apoptotic epithelial cell shedding in an exopolysaccharide and MyD88-dependent manner.

Science.gov (United States)

Hughes, K R; Harnisch, L C; Alcon-Giner, C; Mitra, S; Wright, C J; Ketskemety, J; van Sinderen, D; Watson, A J M; Hall, L J

2017-01-01

Certain members of the microbiota genus Bifidobacterium are known to positively influence host well-being. Importantly, reduced bifidobacterial levels are associated with inflammatory bowel disease (IBD) patients, who also have impaired epithelial barrier function, including elevated rates of apoptotic extrusion of small intestinal epithelial cells (IECs) from villi-a process termed 'cell shedding'. Using a mouse model of pathological cell shedding, we show that mice receiving Bifidobacterium breve UCC2003 exhibit significantly reduced rates of small IEC shedding. Bifidobacterial-induced protection appears to be mediated by a specific bifidobacterial surface exopolysaccharide and interactions with host MyD88 resulting in downregulation of intrinsic and extrinsic apoptotic responses to protect epithelial cells under highly inflammatory conditions. Our results reveal an important and previously undescribed role for B. breve, in positively modulating epithelial cell shedding outcomes via bacterial- and host-dependent factors, supporting the notion that manipulation of the microbiota affects intestinal disease outcomes. © 2017 The Authors.

Replication and shedding kinetics of infectious hematopoietic necrosis virus in juvenile rainbow trout

Science.gov (United States)

Wargo, Andrew R.; Scott, Robert J.; Kerr, Benjamin; Kurath, Gael

2017-01-01

Viral replication and shedding are key components of transmission and fitness, the kinetics of which are heavily dependent on virus, host, and environmental factors. To date, no studies have quantified the shedding kinetics of infectious hematopoietic necrosis virus (IHNV) in rainbow trout (Oncorhynchus mykiss), or how they are associated with replication, making it difficult to ascertain the transmission dynamics of this pathogen of high agricultural and conservation importance. Here, the replication and shedding kinetics of two M genogroup IHNV genotypes were examined in their naturally co-evolved rainbow trout host. Within host virus replication began rapidly, approaching maximum values by day 3 post-infection, after which viral load was maintained or gradually dropped through day 7. Host innate immune response measured as stimulation of Mx-1 gene expression generally followed within host viral loads. Shedding also began very quickly and peaked within 2 days, defining a generally uniform early peak period of shedding from 1 to 4 days after exposure to virus. This was followed by a post-peak period where shedding declined, such that the majority of fish were no longer shedding by day 12 post-infection. Despite similar kinetics, the average shedding rate over the course of infection was significantly lower in mixed compared to single genotype infections, suggesting a competition effect, however, this did not significantly impact the total amount of virus shed. The data also indicated that the duration of shedding, rather than peak amount of virus shed, was correlated with fish mortality. Generally, the majority of virus produced during infection appeared to be shed into the environment rather than maintained in the host, although there was more retention of within host virus during the post-peak period. Viral virulence was correlated with shedding, such that the more virulent of the two genotypes shed more total virus. This fundamental understanding of IHNV

Modeling of lighting behaviour of a hybrid lighting system in inner spaces of Building of Electrical Engineering

Science.gov (United States)

Amado, L.; Osma, G.; Villamizar, R.

2016-07-01

This paper presents the modelling of lighting behaviour of a hybrid lighting system - HLS in inner spaces for tropical climate. HLS aims to mitigate the problem of high electricity consumption used by artificial lighting in buildings. These systems integrate intelligently the daylight and artificial light through control strategies. However, selection of these strategies usually depends on expertise of designer and of available budget. In order to improve the selection process of the control strategies, this paper analyses the Electrical Engineering Building (EEB) case, initially modelling of lighting behaviour is established for the HLS of a classroom and an office. This allows estimating the illuminance level of the mixed lighting in the space, and energy consumption by artificial light according to different lighting control techniques, a control strategy based on occupancy and a combination of them. The model considers the concept of Daylight Factor (DF) for the estimating of daylight illuminance on the work plane for tropical climatic conditions. The validation of the model was carried out by comparing the measured and model-estimated indoor illuminances.

On vortex shedding and prediction of vortex-induced vibrations of circular cylinders

Energy Technology Data Exchange (ETDEWEB)

Halse, Karl Henning

1998-12-31

In offshore installations, many crucial components can be classified as slender marine structures: risers, mooring lines, umbilicals and cables, pipelines. This thesis studies the vortex shedding phenomenon and the problem of predicting vortex-induced vibrations of such structures. As the development of hydrocarbons move to deeper waters, the importance of accurately predicting the vortex-induced response has increased and so the need for proper response prediction methods is large. This work presents an extensive review of existing research publications about vortex shedding from circular cylinders and the vortex-induced vibrations of cylinders and the different numerical approaches to modelling the fluid flow. The response predictions from different methods are found to disagree, both in response shapes and in vibration amplitudes. This work presents a prediction method that uses a fully three-dimensional structural finite element model integrated with a laminar two-dimensional Navier-Stokes solution modelling the fluid flow. This solution is used to study the flow both around a fixed cylinder and in a flexibly mounted one-degree-of-freedom system. It is found that the vortex-shedding process (in the low Reynolds number regime) is well described by the computer program, and that the vortex-induced vibration of the flexibly mounted section do reflect the typical dynamic characteristics of lock-in oscillations. However, the exact behaviour of the experimental results found in the literature was not reproduced. The response of the three-dimensional structural model is larger than the expected difference between a mode shape and a flexibly mounted section. This is due to the use of independent hydrodynamic sections along the cylinder. The predicted response is not unrealistic, and the method is considered a powerful tool. 221 refs., 138 figs., 36 tabs.

On vortex shedding and prediction of vortex-induced vibrations of circular cylinders

Energy Technology Data Exchange (ETDEWEB)

Halse, Karl Henning

1997-12-31

In offshore installations, many crucial components can be classified as slender marine structures: risers, mooring lines, umbilicals and cables, pipelines. This thesis studies the vortex shedding phenomenon and the problem of predicting vortex-induced vibrations of such structures. As the development of hydrocarbons move to deeper waters, the importance of accurately predicting the vortex-induced response has increased and so the need for proper response prediction methods is large. This work presents an extensive review of existing research publications about vortex shedding from circular cylinders and the vortex-induced vibrations of cylinders and the different numerical approaches to modelling the fluid flow. The response predictions from different methods are found to disagree, both in response shapes and in vibration amplitudes. This work presents a prediction method that uses a fully three-dimensional structural finite element model integrated with a laminar two-dimensional Navier-Stokes solution modelling the fluid flow. This solution is used to study the flow both around a fixed cylinder and in a flexibly mounted one-degree-of-freedom system. It is found that the vortex-shedding process (in the low Reynolds number regime) is well described by the computer program, and that the vortex-induced vibration of the flexibly mounted section do reflect the typical dynamic characteristics of lock-in oscillations. However, the exact behaviour of the experimental results found in the literature was not reproduced. The response of the three-dimensional structural model is larger than the expected difference between a mode shape and a flexibly mounted section. This is due to the use of independent hydrodynamic sections along the cylinder. The predicted response is not unrealistic, and the method is considered a powerful tool. 221 refs., 138 figs., 36 tabs.

Modeling of CPDOs - Identifying optimal and implied leverage

DEFF Research Database (Denmark)

Dorn, Jochen

2010-01-01

by Standard & Poor's rating model error which illustrated that closed-form analytical pricing is necessary in order to evaluate and understand complex derivatives. This article aims to shed a light on CPDOs' specific structural enhancements and mechanisms. We quantify inherent risks and provide a dynamic...

Experimental investigation on cavitating flow shedding over an axisymmetric blunt body

Science.gov (United States)

Hu, Changli; Wang, Guoyu; Huang, Biao

2015-03-01

Nowadays, most researchers focus on the cavity shedding mechanisms of unsteady cavitating flows over different objects, such as 2D/3D hydrofoils, venturi-type section, axisymmetric bodies with different headforms, and so on. But few of them pay attention to the differences of cavity shedding modality under different cavitation numbers in unsteady cavitating flows over the same object. In the present study, two kinds of shedding patterns are investigated experimentally. A high speed camera system is used to observe the cavitating flows over an axisymmetric blunt body and the velocity fields are measured by a particle image velocimetry (PIV) technique in a water tunnel for different cavitation conditions. The U-type cavitating vortex shedding is observed in unsteady cavitating flows. When the cavitation number is 0.7, there is a large scale cavity rolling up and shedding, which cause the instability and dramatic fluctuation of the flows, while at cavitation number of 0.6, the detached cavities can be conjunct with the attached part to induce the break-off behavior again at the tail of the attached cavity, as a result, the final shedding is in the form of small scale cavity and keeps a relatively steady flow field. It is also found that the interaction between the re-entrant flow and the attached cavity plays an important role in the unsteady cavity shedding modality. When the attached cavity scale is insufficient to overcome the re-entrant flow, it deserves the large cavity rolling up and shedding just as that at cavitation number of 0.7. Otherwise, the re-entrant flow is defeated by large enough cavity to induce the cavity-combined process and small scale cavity vortexes shedding just as that of the cavitation number of 0.6. This research shows the details of two different cavity shedding modalities which is worthful and meaningful for the further study of unsteady cavitation.

Vortex Shedding Characteristics of the Wake of a Thin Flat Plate with a Circular Trailing Edge

Science.gov (United States)

Rai, Man Mohan

2018-01-01

The near and very near wake of a thin flat plate with a circular trailing edge are investigated with direct numerical simulations (DNS). Data obtained for two different Reynolds numbers (based on plate thickness, D) are the main focus of this study. The separating boundary layers are turbulent in both cases. An earlier investigation of one of the cases (Case F) showed shed vortices in the wake that were about 1.0 D to 4.0 D in spanwise length. Considerable variation in both the strength and frequency of these shed vortices was observed. One objective of the present investigation is to determine the important contributors to this variability in strength and frequency of shed vortices and their finite spanwise extent. Analysis of the data shows that streamwise vortices in the separating boundary layer play an important role in strengthening/weakening of the shed vortices and that high/low-speed streaks in the boundary layer are important contributors to variability in shedding frequency. Both these features of the boundary layer contribute to the finite extent of the vortices in the spanwise direction. The second plate DNS (Case G, with 40 percent of the plate thickness of Case F) shows that while shedding intensity is weaker than obtained in Case F, many of the wake features are similar to that of Case F. This is important in understanding the path to the wake of the thin plate with a sharp trailing edge where shedding is absent. Here we also test the efficacy of a functional relationship between the shedding frequency and the Reynolds numbers based on the boundary layer momentum thickness (Re (sub theta) and D (Re (sub D)); data for developing this behavioral model is from Cases F & G and five earlier DNSs of the flat plate wake.

BLAM (Benthic Light Availability Model): A Proposed Model of Hydrogeomorphic Controls on Light in Rivers

Science.gov (United States)

Julian, J. P.; Doyle, M. W.; Stanley, E. H.

2006-12-01

Light is vital to the dynamics of aquatic ecosystems. It drives photosynthesis and photochemical reactions, affects thermal structure, and influences behavior of aquatic biota. Despite the fundamental role of light to riverine ecosystems, light studies in rivers have been mostly neglected because i) boundary conditions (e.g., banks, riparian vegetation) make ambient light measurements difficult, and ii) the optical water quality of rivers is highly variable and difficult to characterize. We propose a benthic light availability model (BLAM) that predicts the percent of incoming photosynthetically active radiation (PAR) available at the river bed. BLAM was developed by quantifying light attenuation of the five hydrogeomorphic controls that dictate riverine light availability: topography, riparian vegetation, channel geometry, optical water quality, and water depth. BLAM was calibrated using hydrogeomorphic data and light measurements from two rivers: Deep River - a 5th-order, turbid river in central North Carolina, and Big Spring Creek - a 2nd-order, optically clear stream in central Wisconsin. We used a series of four PAR sensors to measure i) above-canopy PAR, ii) PAR above water surface, iii) PAR below water surface, and iv) PAR on stream bed. These measurements were used to develop empirical light attenuation coefficients, which were then used in combination with optical water quality measurements, shading analyses, channel surveys, and flow records to quantify the spatial and temporal variability in riverine light availability. Finally, we apply BLAM to the Baraboo River - a 6th-order, 120-mile, unimpounded river in central Wisconsin - in order to characterize light availability along the river continuum (from headwaters to mouth).

Subclinical herpesvirus shedding among HIV-1-infected men on antiretroviral therapy.

Science.gov (United States)

Agudelo-Hernandez, Arcadio; Chen, Yue; Bullotta, Arlene; Buchanan, William G; Klamar-Blain, Cynthia R; Borowski, Luann; Riddler, Sharon A; Rinaldo, Charles R; Macatangay, Bernard J C

2017-09-24

We evaluated the subclinical shedding of six different herpesviruses in antiretroviral drug-treated HIV-positive [HIV(+)] MSM, and determined how this is associated with markers of inflammation and immune activation. We obtained blood, semen, throat washing, urine, and stool from 15 antiretroviral-treated HIV-1-infected MSM with CD4 T-cell reconstitution, and 12 age-matched HIV-negative [HIV (-)] MSM from the Multicenter AIDS Cohort Study at four timepoints over 24 weeks to measure DNA levels of cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus 1 and 2, human herpesvirus 6 (HHV6), and HHV8. T-cell activation and plasma levels of soluble markers of inflammation and activation were also measured at the corresponding timepoints. HIV(+) participants had a trend for higher total herpesvirus shedding rate. HIV(+) participants also had a significantly higher rate of shedding EBV and CMV compared with the HIV(-) group. Herpesvirus shedding was mostly seen in throat washings. In the HIV(+) group, herpesvirus shedding rate inversely correlated with plasma levels of interferon γ-induced protein 10 and soluble CD163. CMV DNA levels negatively correlated with levels of T-cell activation. There was a trend for a positive correlation between EBV shedding rate and plasma soluble CD14. HHV6 shedding rate negatively correlated with plasma levels of interleukin-6, soluble CD163, and interferon gamma-induced protein 10. Correlations were not observed among HIV(-) individuals. Among treated HIV-infected MSM, there are higher subclinical shedding rates of some herpesviruses that occur in different body compartments and negatively correlate with levels of inflammation and immune activation.

Capacity building in indigenous men's groups and sheds across Australia.

Science.gov (United States)

Southcombe, Amie; Cavanagh, Jillian; Bartram, Timothy

2015-09-01

This article presents an investigation into capacity building, at the community level, in Aboriginal and Torres Strait Islander Men's Groups and Sheds. As safe men's spaces, Men's Groups and Sheds represent an ever-growing social, and health and well-being community service across Australia. The study is qualitative and employs 'yarning circles' (focus groups), semi-structured interviews and observations to gather data from 15 Groups/Sheds involving 45 men from urban, regional and remote communities. We found that capacity building is primarily about securing relationships between Group Leaders/Shed Co-ordinators and Government services. Capacity building establishes links to services such as Centrelink, Medicare, Department of Housing, Probation and Control, and positive outcomes such as Indigenous men securing housing and Centrelink payments. Capacity building results in better health outcomes and, educates and empowers men to improve their social, cultural, emotional and economic well-being. It helps men to better connect with family and community. The current research paves the way for countries worldwide to explore the conceptual and empirical approach of capacity building applicable to other Indigenous [and non-Indigenous] Men's Groups/Sheds. We recommend feasibilities studies, on approaches to capacity building in Indigenous Groups/Sheds, be carried out within urban, regional and remote regions across the country. © The Author (2014). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A pressure-gradient mechanism for vortex shedding in constricted channels

Science.gov (United States)

Boghosian, M. E.; Cassel, K. W.

2013-01-01

Numerical simulations of the unsteady, two-dimensional, incompressible Navier–Stokes equations are performed for a Newtonian fluid in a channel having a symmetric constriction modeled by a two-parameter Gaussian distribution on both channel walls. The Reynolds number based on inlet half-channel height and mean inlet velocity ranges from 1 to 3000. Constriction ratios based on the half-channel height of 0.25, 0.5, and 0.75 are considered. The results show that both the Reynolds number and constriction geometry have a significant effect on the behavior of the post-constriction flow field. The Navier–Stokes solutions are observed to experience a number of bifurcations: steady attached flow, steady separated flow (symmetric and asymmetric), and unsteady vortex shedding downstream of the constriction depending on the Reynolds number and constriction ratio. A sequence of events is described showing how a sustained spatially growing flow instability, reminiscent of a convective instability, leads to the vortex shedding phenomenon via a proposed streamwise pressure-gradient mechanism. PMID:24399860

Lectures on algebraic model theory

CERN Document Server

Hart, Bradd

2001-01-01

In recent years, model theory has had remarkable success in solving important problems as well as in shedding new light on our understanding of them. The three lectures collected here present recent developments in three such areas: Anand Pillay on differential fields, Patrick Speissegger on o-minimality and Matthias Clasen and Matthew Valeriote on tame congruence theory.

Falling, flapping, flying, swimming,...: High-Re fluid-solid interactions with vortex shedding

Science.gov (United States)

Michelin, Sebastien Honore Roland

The coupling between the motion of a solid body and the dynamics of the surrounding flow is essential to the understanding of a large number of engineering and physical problems, from the stability of a slender structure exposed to the wind to the locomotion of insects, birds and fishes. Because of the strong coupling on a moving boundary of the equations for the solid and fluid, the simulation of such problems is computationally challenging and expensive. This justifies the development of simplified models for the fluid-solid interactions to study their physical properties and behavior. This dissertation proposes a reduced-order model for the interaction of a sharp-edged solid body with a strongly unsteady high Reynolds number flow. In such a case, viscous forces in the fluid are often negligible compared to the fluid inertia or the pressure forces, and the thin boundary layers separate from the solid at the edges, leading to the shedding of large and persistent vortices in the solid's wake. A general two-dimensional framework is presented based on complex potential flow theory. The formation of the solid's vortical wake is accounted for by the shedding of point vortices with unsteady intensity from the solid's sharp edges, and the fluid-solid problem is reformulated exclusively as a solid-vortex interaction problem. In the case of a rigid solid body, the coupled problem is shown to reduce to a set of non-linear ordinary differential equations. This model is used to study the effect of vortex shedding on the stability of falling objects. The solid-vortex model is then generalized to study the fluttering instability and non-linear flapping dynamics of flexible plates or flags. The uttering instability and resulting flapping motion result from the competing effects of the fluid forcing and of the solid's flexural rigidity and inertia. Finally, the solid-vortex model is applied to the study of the fundamental effect of bending rigidity on the flapping performance of

Modeling Water Clarity and Light Quality in Oceans

Directory of Open Access Journals (Sweden)

Mohamed A. Abdelrhman

2016-11-01

Full Text Available Phytoplankton is a primary producer of organic compounds, and it forms the base of the food chain in ocean waters. The concentration of phytoplankton in the water column controls water clarity and the amount and quality of light that penetrates through it. The availability of adequate light intensity is a major factor in the health of algae and phytoplankton. There is a strong negative coupling between light intensity and phytoplankton concentration (e.g., through self-shading by the cells, which reduces available light and in return affects the growth rate of the cells. Proper modeling of this coupling is essential to understand primary productivity in the oceans. This paper provides the methodology to model light intensity in the water column, which can be included in relevant water quality models. The methodology implements relationships from bio-optical models, which use phytoplankton chlorophyll a (chl-a concentration as a surrogate for light attenuation, including absorption and scattering by other attenuators. The presented mathematical methodology estimates the reduction in light intensity due to absorption by pure seawater, chl-a pigment, non-algae particles (NAPs and colored dissolved organic matter (CDOM, as well as backscattering by pure seawater, phytoplankton particles and NAPs. The methods presented facilitate the prediction of the effects of various environmental and management scenarios (e.g., global warming, altered precipitation patterns, greenhouse gases on the wellbeing of phytoplankton communities in the oceans as temperature-driven chl-a changes take place.

Counter and Complicit Masculine Discourse Among Men’s Shed Members

Science.gov (United States)

Mackenzie, Corey S.; Roger, Kerstin; Robertson, Steve; Oliffe, John L.; Nurmi, Mary Anne; Urquhart, James

2017-01-01

Men’s Sheds is a growing international movement aimed at providing men with places and activities that facilitate social connectedness. Despite Men’s Sheds’ focus on males, little attention has been paid to masculinities within the specific context of these settings. The current study used a gender relations framework to explore the ways in which attendees discussed Men’s Sheds, with particular attention to discussions that were complicit and counter to traditional, hegemonic views of masculinity, and diverse positions in between these binaries. The data consisted of transcripts and field notes from four focus groups comprising mostly older, White, retired male members of a Canadian shed (N = 22). The analysis revealed three overall themes: (1) focus on work, (2) independence, and (3) need for male-focused spaces. These themes and associated subthemes suggest that shed members ascribe to dominant masculine values and ideals, but also support more fluid and flexible views of masculinity. Implications are discussed for how working with an array of masculinities within the Men’s Sheds movement will be helpful with respect to their future growth in Canada and internationally. PMID:28068851

Two-Stage Load Shedding for Secondary Control in Hierarchical Operation of Islanded Microgrids

DEFF Research Database (Denmark)

Zhou, Quan; Li, Zhiyi; Wu, Qiuwei

2018-01-01

A two-stage load shedding scheme is presented to cope with the severe power deficit caused by microgrid islanding. Coordinated with the fast response of inverter-based distributed energy resources (DERs), load shedding at each stage and the resulting power flow redistribution are estimated....... The first stage of load shedding will cease rapid frequency decline in which the measured frequency deviation is employed to guide the load shedding level and process. Once a new steady-state is reached, the second stage is activated, which performs load shedding according to the priorities of loads...

Studies of Human 2,4-Dienoyl CoA Reductase Shed New Light on Peroxisomal β-Oxidation of Unsaturated Fatty Acids

Energy Technology Data Exchange (ETDEWEB)

Hua, Tian; Wu, Dong; Ding, Wei; Wang, Jiangyun; Shaw, Neil; Liu, Zhi-Jie [Nankai; (Chinese Aca. Sci.)

2012-10-15

Peroxisomes play an essential role in maintaining fatty acid homeostasis. Although mitochondria are also known to participate in the catabolism of fatty acids via β-oxidation, differences exist between the peroxisomal and mitochondrial β-oxidation. Only peroxisomes, but not mitochondrion, can shorten very long chain fatty acids. Here, we describe the crystal structure of a ternary complex of peroxisomal 2,4-dienoyl CoA reductases (pDCR) with hexadienoyl CoA and NADP, as a prototype for comparison with the mitochondrial 2,4-dienoyl CoA reductase (mDCR) to shed light on the differences between the enzymes from the two organelles at the molecular level. Unexpectedly, the structure of pDCR refined to 1.84 Å resolution reveals the absence of the tyrosine-serine pair seen in the active site of mDCR, which together with a lysine and an asparagine have been deemed a hallmark of the SDR family of enzymes. Instead, aspartate hydrogen-bonded to the Cα hydroxyl via a water molecule seems to perturb the water molecule for protonation of the substrate. Our studies provide the first structural evidence for participation of water in the DCR-catalyzed reactions. Biochemical studies and structural analysis suggest that pDCRs can catalyze the shortening of six-carbon-long substrates in vitro. However, the Km values of pDCR for short chain acyl CoAs are at least 6-fold higher than those for substrates with 10 or more aliphatic carbons. Unlike mDCR, hinge movements permit pDCR to process very long chain polyunsaturated fatty acids.

Impact of Shed/Soluble targets on the PK/PD of approved therapeutic monoclonal antibodies.

Science.gov (United States)

Samineni, Divya; Girish, Sandhya; Li, Chunze

2016-12-01

Suboptimal treatment for monoclonal antibodies (mAbs) directed against endogenous circulating soluble targets and the shed extracellular domains (ECD) of the membrane-bound targets is an important clinical concern due to the potential impact of mAbs on the in vivo efficacy and safety. Consequently, there are considerable challenges in the determination of an optimal dose and/or dosing regimen. Areas covered: This review outlines the impact of shed antigen targets from membrane-bound proteins and soluble targets on the PK and/or PD of therapeutic mAbs that have been approved in the last decade. We discuss various bioanalytical techniques that have facilitated the interpretation of the PK/PD properties of therapeutic mAbs and also considered the factors that may impact such measurements. Quantitative approaches include target-mediated PK models and bi- or tri-molecular interaction PK/PD models that describe the relationships between the antibody PK and the ensuing effects on PD biomarkers, to facilitate the mAb PK/PD characterization. Expert commentary: The proper interpretation of PK/PD relationships through the integrated PK/PD modeling and bioanalytical strategy facilitates a mechanistic understanding of the disease processes and dosing regimen optimization, thereby offering insights into developing effective therapeutic regimens. This review provides an overview of the impact of soluble targets or shed ECD on mAb PK/PD properties. We provide examples of quantitative approaches that facilitate the characterization of mAb PK/PD characteristics and their corresponding bioanalytical strategies.

The different growth pathways of Brightest Cluster Galaxies and the Intra-Cluster Light

Science.gov (United States)

Contini, E.; Yi, S. K.; Kang, X.

2018-06-01

We study the growth pathways of Brightest Central Galaxies (BCGs) and Intra-Cluster Light (ICL) by means of a semi-analytic model. We assume that the ICL forms by stellar stripping of satellite galaxies and violent processes during mergers, and implement two independent models: (1) one considers both mergers and stellar stripping (named STANDARD model), and one considers only mergers (named MERGERS model). We find that BCGs and ICL form, grow and overall evolve at different times and with different timescales, but they show a clear co-evolution after redshift z ˜ 0.7 - 0.8. Around 90% of the ICL from stellar stripping is built-up in the innermost 150 Kpc from the halo centre and the dominant contribution comes from disk-like galaxies (B/Tcluster other than the BCG, at z = 0. We then suggest that this quantity is a valid observable that can shed light on the relative importance of mergers and stellar stripping for the formation of the ICL.

Review of the Phenomenon of Ice Shedding from Wind Turbine Blades

Directory of Open Access Journals (Sweden)

H Xue

2016-08-01

Full Text Available Wind power is a sustainable source of energy. However, there are certain challenges to be  overcome. One of the operational challenges is the phenomenon of ice shedding. Icing happens on wind turbine blades in cold regions. When ice grows to a certain size, it separates from the wind turbine blades resulting in the phenomenon of ice shedding. This phenomenon is of significantly dangerous for equipment and personnel in the region. Ice shedding may happen either because of vibrations or bending in blades. However, it was noticed by operators at Nygårdsfjell wind park, Narvik, Norway that ice shedding is more probable to happen when blades are stopped and turned back on. This observation reveals the fact that bending of blades (from loaded to unloaded positions allows the ice to separate and hence result in ice shedding. This can be linked to the phenomenon of icing, mechanical and adhesive properties of ice. This paper reviews above in detail.

Stochastic oscillations induced by vortex shedding in wind

DEFF Research Database (Denmark)

Christensen, Claus

1997-01-01

As a fluid flows past a circular cylinder,vortices are shed alternately from each side at most values of the Reynolds number. Over a certain range of windspeeds, the periodicity in the wake is synchronized or captured by the mechanical system. The shedding abruptly deviates from the linear Strouhal...... dependence and stays constant at the mechanical natural frequency. This coupling between the velocity field and the motion of the mechanical system is referred to as the lock-in phenomenon. The lock-in phenomenon has importance in structural engineering for slightly damped slender structures exposed to wind...... in the wake is synchronized or captured by the mechanical system. The shedding abruptly deviates from the linear Strouhal dependence and stays constant at the mechanical natural frequency. This coupling between the velocity field and the motion of the mechanical system is referred to as the lock-in phenomenon...

Modulation of statin-activated shedding of Alzheimer APP ectodomain by ROCK.

Directory of Open Access Journals (Sweden)

Steve Pedrini

2005-01-01

Full Text Available Statins are widely used cholesterol-lowering drugs that act by inhibiting HMGCoA reductase, the rate-limiting enzyme in cholesterol biosynthesis. Recent evidence suggests that statin use may be associated with a decreased risk for Alzheimer disease, although the mechanisms underlying this apparent risk reduction are poorly understood. One popular hypothesis for statin action is related to the drugs' ability to activate alpha-secretase-type shedding of the alpha-secretase-cleaved soluble Alzheimer amyloid precursor protein ectodomain (sAPP(alpha. Statins also inhibit the isoprenoid pathway, thereby modulating the activities of the Rho family of small GTPases-Rho A, B, and C-as well as the activities of Rac and cdc42. Rho proteins, in turn, exert many of their effects via Rho-associated protein kinases (ROCKs. Several cell-surface molecules are substrates for activated alpha-secretase-type ectodomain shedding, and regulation of shedding typically occurs via activation of protein kinase C or extracellular-signal-regulated protein kinases, or via inactivation of protein phosphatase 1 or 2A. However, the possibility that these enzymes play a role in statin-stimulated shedding has been excluded, leading us to investigate whether the Rho/ROCK1 protein phosphorylation pathway might be involved.We found that both atorvastatin and simvastatin stimulated sAPP(alpha shedding from a neuroblastoma cell line via a subcellular mechanism apparently located upstream of endocytosis. A farnesyl transferase inhibitor also increased sAPP(alpha shedding, as did a dominant negative form of ROCK1. Most conclusively, a constitutively active ROCK1 molecule inhibited statin-stimulated sAPP(alpha shedding.Together, these data suggest that statins exert their effects on shedding of sAPP(alpha from cultured cells, at least in part, by modulation of the isoprenoid pathway and ROCK1.

Modelling of classical ghost images obtained using scattered light

International Nuclear Information System (INIS)

Crosby, S; Castelletto, S; Aruldoss, C; Scholten, R E; Roberts, A

2007-01-01

The images obtained in ghost imaging with pseudo-thermal light sources are highly dependent on the spatial coherence properties of the incident light. Pseudo-thermal light is often created by reducing the coherence length of a coherent source by passing it through a turbid mixture of scattering spheres. We describe a model for simulating ghost images obtained with such partially coherent light, using a wave-transport model to calculate the influence of the scattering on initially coherent light. The model is able to predict important properties of the pseudo-thermal source, such as the coherence length and the amplitude of the residual unscattered component of the light which influence the resolution and visibility of the final ghost image. We show that the residual ballistic component introduces an additional background in the reconstructed image, and the spatial resolution obtainable depends on the size of the scattering spheres

Modelling of classical ghost images obtained using scattered light

Energy Technology Data Exchange (ETDEWEB)

Crosby, S; Castelletto, S; Aruldoss, C; Scholten, R E; Roberts, A [School of Physics, University of Melbourne, Victoria, 3010 (Australia)

2007-08-15

The images obtained in ghost imaging with pseudo-thermal light sources are highly dependent on the spatial coherence properties of the incident light. Pseudo-thermal light is often created by reducing the coherence length of a coherent source by passing it through a turbid mixture of scattering spheres. We describe a model for simulating ghost images obtained with such partially coherent light, using a wave-transport model to calculate the influence of the scattering on initially coherent light. The model is able to predict important properties of the pseudo-thermal source, such as the coherence length and the amplitude of the residual unscattered component of the light which influence the resolution and visibility of the final ghost image. We show that the residual ballistic component introduces an additional background in the reconstructed image, and the spatial resolution obtainable depends on the size of the scattering spheres.

Leading-edge vortex shedding from rotating wings

Energy Technology Data Exchange (ETDEWEB)

Kolomenskiy, Dmitry [Centre de Recherches Mathématiques (CRM), Department of Mathematics and Statistics, McGill University, 805 Sherbrooke W., Montreal, QC H3A 0B9 (Canada); Elimelech, Yossef [Faculty of Aerospace Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Schneider, Kai, E-mail: dkolom@gmail.com [M2P2–CNRS, Université d' Aix-Marseille, 39, rue Frédéric Joliot-Curie, F-13453 Marseille Cedex 13 (France)

2014-06-01

This paper presents a numerical investigation of the leading-edge vortices generated by rotating triangular wings at Reynolds number Re = 250. A series of three-dimensional numerical simulations have been carried out using a Fourier pseudo-spectral method with volume penalization. The transition from stable attachment of the leading-edge vortex to periodic vortex shedding is explored, as a function of the wing aspect ratio and the angle of attack. It is found that, in a stable configuration, the spanwise flow in the recirculation bubble past the wing is due to the centrifugal force, incompressibility and viscous stresses. For the flow outside of the bubble, an inviscid model of spanwise flow is presented. (papers)

Shedding New Light on Project Portfolio Risk Management

Directory of Open Access Journals (Sweden)

Mariusz Hofman

2017-10-01

Full Text Available This paper constitutes an innovative attempt to analyse the risks and negative phenomena dependencies within a project portfolio. Based on the available literature, the risks and negative phenomena (that is, the problems with the availability of resources, interpersonal conflicts, irregularities in the portfolio balance, etc. specific to a project portfolio were identified. Theoretical constructs were then used to connect the identified risks with the negative phenomena. Structural equations were used to confirm the existence and quality of these constructs, as well as models describing connections between phenomena. The determination of the structural equations also provided a setting in which statistical methods (χ2, RMSEA and CFI could be used to investigate the level of fit of the constructs and models to the empirical data.

The Transition from Thick to Thin Plate Wake Physics: Whither Vortex Shedding?

Science.gov (United States)

Rai, Man Mohan

2016-01-01

The near and very near wake of a flat plate with a circular trailing edge is investigated with data from direct numerical simulations. Computations were performed for six different combinations of the Reynolds numbers based on plate thickness (D) and boundary layer momentum thickness upstream of the trailing edge (theta). Unlike the case of the cylinder, these Reynolds numbers are independent parameters for the flat plate. The separating boundary layers are turbulent in all the cases investigated. One objective of the study is to understand the changes in the wake vortex shedding process as the plate thickness is reduced (increasing theta/D). The value of D varies by a factor of 16 and that of theta by approximately 5 in the computations. Vortex shedding is vigorous in the low theta/D cases with a substantial decrease in shedding intensity in the large theta/D cases. Other shedding characteristics are also significantly altered with increasing theta/D. A visualization of the shedding process in the different cases is provided and discussed. The basic shedding mechanism is explored in depth. The effect of changing theta/D on the time-averaged, near-wake velocity statistics is also discussed. A functional relationship between the shedding frequency and the Reynolds numbers mentioned above is obtained.

Cervical Shedding of HIV-1 RNA Among Women With Low Levels of Viremia While Receiving Highly Active Antiretroviral Therapy

Science.gov (United States)

Neely, Michael N.; Benning, Lorie; Xu, Jiaao; Strickler, Howard D.; Greenblatt, Ruth M.; Minkoff, Howard; Young, Mary; Bremer, James; Levine, Alexandra M.; Kovacs, Andrea

2011-01-01

Background Among women with low o r undetectable quantities of HIV-1 RNA in plasma, factors associated with genital HIV-1 RNA shedding, including choice of treatment regimen, are poorly characterized. Methods We measured HIV-1 RNA in cervical swab specimens obtained from participants in the Women’s Interagency HIV Study who had concurrent plasma viral RNA levels <500 copies/mL, and we assessed factors associated with genital HIV shedding. The study was powered to determine the relative effects of antiretroviral protease inhibitors (PIs) versus nonnucleoside reverse transcriptase inhibitors (NNRTIs) on viral RNA shedding. Results Overall, 44 (15%) of 290 women had detectable HIV-1 RNA in cervical specimens. In the final multivariate model, shedding was independently associated with NNRTI (vs. PI) use (odds ratio [OR], 95% confidence interval [CI]: 2.24, 1.13 to 4.45) and illicit drug use (OR, 95% CI: 2.41, 0.96 to 5.69). Conclusions This is the largest study to define risks for genital HIV-1 RNA shedding in women with low/undetectable plasma virus. Shedding in this population was common, and NNRTI-based highly active antiretroviral therapy (HAART) (vs. PI-based HAART) was associated with genital HIV shedding. Further study is required to determine the impact of these findings on transmission of HIV from mother to child or to sexual partners. PMID:17106279

Current-voltage model of LED light sources

DEFF Research Database (Denmark)

Beczkowski, Szymon; Munk-Nielsen, Stig

2012-01-01

Amplitude modulation is rarely used for dimming light-emitting diodes in polychromatic luminaires due to big color shifts caused by varying magnitude of LED driving current and nonlinear relationship between intensity of a diode and driving current. Current-voltage empirical model of light...

Monte Carlo and Lambertian light guide models of the light output from scintillation crystals at megavoltage energies

International Nuclear Information System (INIS)

Evans, Philip M.; Mosleh-Shirazi, M. Amin; Harris, Emma J.; Seco, Joao

2006-01-01

A new model of the light output from single-crystal scintillators in megavoltage energy x-ray beams has been developed, based on the concept of a Lambertian light guide model (LLG). This was evaluated in comparison with a Monte Carlo (MC) model of optical photon transport, previously developed and reported in the literature, which was used as a gold standard. The LLG model was developed to enable optimization of scintillator detector design. In both models the dose deposition and light propagation were decoupled, the scintillators were cuboids, split into a series of cells as a function of depth, with Lambertian side and entrance faces, and a specular exit face. The signal in a sensor placed 1 and 1000 mm beyond the exit face was calculated. Cesium iodide (CSI) crystals of 1.5 and 3 mm square cross section and 1, 5, and 10 mm depth were modeled. Both models were also used to determine detector signal and optical gain factor as a function of CsI scintillator thickness, from 2 to 10 mm. Results showed a variation in light output with position of dose deposition of a factor of up to approximately 5, for long, thin scintillators (such as 10x1.5x1.5 mm 3 ). For short, fat scintillators (such as 1x3x3 mm 3 ) the light output was more uniform with depth. MC and LLG generally agreed to within 5%. Results for a sensor distance of 1 mm showed an increase in light output the closer the light originates to the exit face, while a distance of 1000 mm showed a decrease in light output the closer the light originates to the exit face. For a sensor distance of 1 mm, the ratio of signal for a 10 mm scintillator to that for a 2 mm scintillator was 1.98, whereas for the 1000 mm distance the ratio was 3.00. The ratio of quantum efficiency (QE) between 10 and 2 mm thicknesses was 4.62. We conclude that these models may be used for detector optimization, with the light guide model suitable for parametric study

Men's Sheds function and philosophy: towards a framework for future research and men's health promotion.

Science.gov (United States)

Wilson, Nathan J; Cordier, Reinie; Doma, Kenji; Misan, Gary; Vaz, Sharmila

2015-08-01

The Men's Shed movement supports a range of men's health promotion initiatives. This paper examines whether a Men's Shed typology could inform future research and enable more efficient and targeted health promotion activities through Men's Sheds. The International Men's Shed Survey consisted of a cross-sectional exploration of sheds, their members, and health and social activities. Survey data about shed 'function' and 'philosophy' were analysed using descriptive and inferential statistics. A framework of Men's Sheds based on function and philosophy demonstrated that most sheds serve a primary utility function, a secondary social function, but most importantly a primary social opportunity philosophy. Sheds with a primary health philosophy participated in fewer health promotion activities when compared with sheds without a primary health philosophy. In addition to the uniform health promotion resources distributed by the Men's Shed associations, specific health promotion activities, such as prostate education, are being initiated from an individual shed level. This framework can potentially be used to enable future research and health promotion activities to be more efficiently and effectively targeted. SO WHAT? Men experience poorer health and well being outcomes than women. This framework offers a novel approach to providing targeted health promotion activities to men in an environment where it is okay to talk about men's health.

Influence of particle shedding from silicone tubing on antibody stability.

Science.gov (United States)

Saller, Verena; Hediger, Constanze; Matilainen, Julia; Grauschopf, Ulla; Bechtold-Peters, Karoline; Mahler, Hanns-Christian; Friess, Wolfgang

2018-05-01

Peristaltic pumps are increasingly employed during fill & finish operations of a biopharmaceutical drug, due to sensitivity of many biological products to rotary piston pump-related stresses. Yet, possibly also unit operations using peristaltic pumps may shed particulates into the final product due to abrasion from the employed tubing. It was the aim of this study to elucidate the potential influence of particles shed from peristaltic pump tubing on the stability of a drug product. Spiking solutions containing shed silicone particles were prepared via peristaltic pumping of placebo under recirculating conditions and subsequently characterized. Two formulated antibodies were spiked with two realistic, but worst-case levels of particles and a 6-month accelerated stability study with storage at 2-8, 25 and 40°C were conducted. Regarding the formation of aggregates and fragments, both mAbs degraded at their typically expected rates and no additional impact of spiked particles was observed. No changes were discerned however in turbidity, subvisible and visible particle assessments. Flow imaging data for one of the mAb formulations with spiked particles suggested limited colloidal stability of shed particles as indicated by a similar increase in spiked placebo. Shed silicone particles from peristaltic pump tubing are assumed to not impair drug product stability. © 2016 Royal Pharmaceutical Society.

Porphyromonas gingivalis-mediated shedding of extracellular matrix metalloproteinase inducer (EMMPRIN) by oral epithelial cells: a potential role in inflammatory periodontal disease.

Science.gov (United States)

Feldman, Mark; La, Vu Dang; Lombardo Bedran, Telma Blanca; Palomari Spolidorio, Denise Madalena; Grenier, Daniel

2011-12-01

Extracellular matrix metalloproteinase inducer (EMMPRIN) or CD147 is a transmembrane glycoprotein expressed by various cell types, including oral epithelial cells. Recent studies have brought evidence that EMMPRIN plays a role in periodontitis. In the present study, we investigated the effect of Porphyromonas gingivalis, a major pathogen in chronic periodontitis, on the shedding of membrane-anchored EMMPRIN and on the expression of the EMMPRIN gene by oral epithelial cells. A potential contribution of shed EMMPRIN to the inflammatory process of periodontitis was analyzed by evaluating the effect of recombinant EMMPRIN on cytokine and matrix metalloproteinase (MMP) secretion by human gingival fibroblasts. ELISA and immunofluorescence analyses revealed that P. gingivalis mediated the shedding of epithelial cell-surface EMMPRIN in a dose- and time-dependent manner. Cysteine proteinase (gingipain)-deficient P. gingivalis mutants were used to demonstrate that both Arg- and Lys-gingipain activities are involved in EMMPRIN shedding. Real-time PCR showed that P. gingivalis had no significant effect on the expression of the EMMPRIN gene in epithelial cells. Recombinant EMMPRIN induced the secretion of IL-6 and MMP-3 by gingival fibroblasts, a phenomenon that appears to involve mitogen activated protein kinases. The present study brought to light a new mechanism by which P. gingivalis can promote the inflammatory response during periodontitis. Copyright © 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Genetic relationship between wool shedding in ewe-lambs and ewes

Science.gov (United States)

Interest in reducing labor costs related to shearing has led to the development of breeds that naturally shed their wool annually. This goal has been achieved by introducing hair-sheep genetics. These developments are relatively recent and thus the genetic underpinnings of wool shedding (WS) are not...

Developing of the EV charging and parking shed of BIPV

Institute of Scientific and Technical Information of China (English)

Wu Shaobo; Wei Chuanchuan; Yu Jiang

2013-01-01

Building-integrated photovoltaic (BIPV) is an important application way of solar photovoltaic power. The electric vehicle (EV) charging and parking shed of BIPV is the regeneration energy intellectual integration demonstration application system collection of photovoltaic (PV) grid power,PV off-grid power,EV charging and parking shed,and any part of the functions and their combination will be engaged in practical application on demand. The paper describes the PV shed system structure and design in detail with the present of its actual photos. The shed is 50 m long and 5.5 m wide and capable of parking 18 cars. Under the control of system intellectual con-troller,the power produced by PV from sunlight will charge the parking EV car prior to charging the storage bat-tery,charging the storage battery prior to grid power,grid power at last,and charge the EV by utility grid when it is a cloudy or rainy day.

From Ordinary Differential Equations to Structural Causal Models: the deterministic case

NARCIS (Netherlands)

Mooij, J.M.; Janzing, D.; Schölkopf, B.; Nicholson, A.; Smyth, P.

2013-01-01

We show how, and under which conditions, the equilibrium states of a first-order Ordinary Differential Equation (ODE) system can be described with a deterministic Structural Causal Model (SCM). Our exposition sheds more light on the concept of causality as expressed within the framework of

Light-limited growth and competition for light in well-mixed aquatic environments : An elementary model

NARCIS (Netherlands)

Huisman, Jef; Weissing, F.J.

Light is never distributed homogeneously since it forms a gradient over biomass. As a consequence, the common theories on nutrient competition are not applicable to competition for light. In this paper, we investigate a model for light-limited growth and competition among phytoplankton species in a

Forest Carbon Offsets Revisited: Shedding Light on Darkwoods

NARCIS (Netherlands)

Kooten, van G.C.; Bogle, T.; Vries, de F.P.

2015-01-01

This paper investigates the viability of carbon offset credits created through forest conservation and preservation. A detailed forest management model based on a case study of a forest estate in southeastern British Columbia, owned by The Nature Conservancy of Canada (NCC) is used to demonstrate

Modeling of CPDOs - Identifying Optimal and Implied Leverage

DEFF Research Database (Denmark)

Dorn, Jochen

famous notably by Standard & Poor's rating model error which illustrated that closed-form analytical pricing is necessary in order to evaluate and understand complex derivatives. This article aims to shed a light on CPDOs specific structural enhancements and mechanisms. The author quantifies inherent...... risks and provides a dynamic closed-form pricing formula....

Application of computational intelligence techniques for load shedding in power systems: A review

International Nuclear Information System (INIS)

Laghari, J.A.; Mokhlis, H.; Bakar, A.H.A.; Mohamad, Hasmaini

2013-01-01

Highlights: • The power system blackout history of last two decades is presented. • Conventional load shedding techniques, their types and limitations are presented. • Applications of intelligent techniques in load shedding are presented. • Intelligent techniques include ANN, fuzzy logic, ANFIS, genetic algorithm and PSO. • The discussion and comparison between these techniques are provided. - Abstract: Recent blackouts around the world question the reliability of conventional and adaptive load shedding techniques in avoiding such power outages. To address this issue, reliable techniques are required to provide fast and accurate load shedding to prevent collapse in the power system. Computational intelligence techniques, due to their robustness and flexibility in dealing with complex non-linear systems, could be an option in addressing this problem. Computational intelligence includes techniques like artificial neural networks, genetic algorithms, fuzzy logic control, adaptive neuro-fuzzy inference system, and particle swarm optimization. Research in these techniques is being undertaken in order to discover means for more efficient and reliable load shedding. This paper provides an overview of these techniques as applied to load shedding in a power system. This paper also compares the advantages of computational intelligence techniques over conventional load shedding techniques. Finally, this paper discusses the limitation of computational intelligence techniques, which restricts their usage in load shedding in real time

Light-light and heavy-light mesons in the model of QCD string with quarks at the ends

CERN Document Server

Nefediev, A V

2002-01-01

The variational einbein field method is applied to the model of the QCD string with quarks at the ends for the case of light-light and heavy-light mesons. Special attention is payed to the proper string dynamics. The correct string slope of the Regge trajectories is reproduced for light-light states which comes out from the picture of rotating string. Masses of several low-lying orbitally and radially excited states in the D, D_s, B, and B_s meson spectra are calculated and a good agreement with the experimental data as well as with recent lattice calculations is found. The role of the string correction to the interquark interaction is discussed at the example of the identification of D*'(2637) state recently claimed by DELPHI Collaboration. For the heavy-light mesons the standard constants used in Heavy Quark Effective Theory are extracted and compared to the results of other approaches.

ADAM15 is involved in MICB shedding and mediates the effects of gemcitabine on MICB shedding in PANC-1 pancreatic cancer cells.

Science.gov (United States)

Duan, Xiaohui; Mao, Xianhai; Sun, Weijia

2013-03-01

The aim of this study was to investigate the role of ADAM15 in MHC class I polypeptide-related sequence B (MICB) protein ectodomain shedding and observe whether or not gemcitabine affects MICB shedding from PANC-1 cells. In this study, immunohistochemistry of MICB and ADAM15 were performed on tumor samples obtained from 93 patients with pancreatic ductal adenocarcinoma (PDAC). The expression of MICB and ADAM15 in the PDAC tissues was significantly higher compared with that in the normal tissues of the pancreas. Statistical analysis showed a significant correlation between the expression of MICB and certain classic clinicopathological characteristics (i.e., histological grade and TNM stage). ADAM15 expression was found to correlate with lymph node metastasis and TNM stage. The Spearman's rank test suggested that the expression of MICB was inversely correlated with that of ADAM15 in PDAC tissues. Knockdown of ADAM15 in PANC-1 cells clearly upregulated MICB expression on the cellular surface and downregulated soluble MICB (sMICB) levels in the culture supernatants. A non-toxic dose of 0.5 µmol/l gemcitabine suppresses ADAM15 expression leading, at the same time, to an increase in MICB expression and a decrease in sMICB production in PANC-1 cells. The mRNA levels of MICB did not change following PANC-1 exposure to gemcitabine. Further study suggests that the suppressive effect of gemcitabine on MICB shedding in PANC-1 cells is mediated by ADAM15 downregulation. In conclusion, the results of the present study support the hypothesis that ADAM15 is involved in MICB shedding of PANC-1 cells and that gemcitabine inhibits MICB ectodomain shedding through the suppression of ADAM15.

LHCf sheds new light on cosmic rays

CERN Multimedia

Anaïs Schaeffer

2011-01-01

The energy spectrum of the single photon obtained using data from the LHCf experiment has turned out to be very different from that predicted by the theoretical models used until now to describe the interactions between very high-energy cosmic rays and the earth's atmosphere. The consequences of this discrepancy for cosmic ray studies could be significant.   Artistic impression of cosmic rays entering Earth's atmosphere. (Credit: Asimmetrie/Infn). It took physicists by surprise when analysis of the data collected by the two LHCf calorimeters in 2010 showed that high-energy cosmic rays don't interact with the atmosphere in the manner predicted by theory. The LHCf detectors, set up 140 metres either side of the ATLAS interaction point, are dedicated to the study of the secondary particles emitted at very small angles during proton-proton collisions in the LHC, with energies comparable to cosmic rays entering the earth's atmosphere at 2.5x1016 eV. The aim of the experiment is to r...

The Gamma-Ray Burst ToolSHED is Open for Business

Science.gov (United States)

Giblin, Timothy W.; Hakkila, Jon; Haglin, David J.; Roiger, Richard J.

2004-09-01

The GRB ToolSHED, a Gamma-Ray Burst SHell for Expeditions in Data-Mining, is now online and available via a web browser to all in the scientific community. The ToolSHED is an online web utility that contains pre-processed burst attributes of the BATSE catalog and a suite of induction-based machine learning and statistical tools for classification and cluster analysis. Users create their own login account and study burst properties within user-defined multi-dimensional parameter spaces. Although new GRB attributes are periodically added to the database for user selection, the ToolSHED has a feature that allows users to upload their own burst attributes (e.g. spectral parameters, etc.) so that additional parameter spaces can be explored. A data visualization feature using GNUplot and web-based IDL has also been implemented to provide interactive plotting of user-selected session output. In an era in which GRB observations and attributes are becoming increasingly more complex, a utility such as the GRB ToolSHED may play an important role in deciphering GRB classes and understanding intrinsic burst properties.

Residuals and the Residual-Based Statistic for Testing Goodness of Fit of Structural Equation Models

Science.gov (United States)

Foldnes, Njal; Foss, Tron; Olsson, Ulf Henning

2012-01-01

The residuals obtained from fitting a structural equation model are crucial ingredients in obtaining chi-square goodness-of-fit statistics for the model. The authors present a didactic discussion of the residuals, obtaining a geometrical interpretation by recognizing the residuals as the result of oblique projections. This sheds light on the…

Improved spring model-based collaborative indoor visible light positioning

Science.gov (United States)

Luo, Zhijie; Zhang, WeiNan; Zhou, GuoFu

2016-06-01

Gaining accuracy with indoor positioning of individuals is important as many location-based services rely on the user's current position to provide them with useful services. Many researchers have studied indoor positioning techniques based on WiFi and Bluetooth. However, they have disadvantages such as low accuracy or high cost. In this paper, we propose an indoor positioning system in which visible light radiated from light-emitting diodes is used to locate the position of receivers. Compared with existing methods using light-emitting diode light, we present a high-precision and simple implementation collaborative indoor visible light positioning system based on an improved spring model. We first estimate coordinate position information using the visible light positioning system, and then use the spring model to correct positioning errors. The system can be employed easily because it does not require additional sensors and the occlusion problem of visible light would be alleviated. We also describe simulation experiments, which confirm the feasibility of our proposed method.

A PROBABILISTIC EXPOSURE ASSESSMENT FOR CHILDREN WHO CONTACT CCA-TREATED PLAYSETS AND DECKS USING THE STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION (SHEDS) MODEL FOR THE WOOD PRESERVATIVE EXPOSURE SCENARIO

Science.gov (United States)

The U.S. Environmental Protection Agency has conducted a probabilistic exposure and dose assessment on the arsenic (As) and chromium (Cr) components of Chromated Copper Arsenate (CCA) using the Stochastic Human Exposure and Dose Simulation model for wood preservatives (SHEDS-Wood...

Men's re-placement: Social practices in a Men's Shed.

Science.gov (United States)

Anstiss, David; Hodgetts, Darrin; Stolte, Ottilie

2018-05-06

Transitions into retirement can be difficult at the best of times. Many men find themselves having to reflect on who they are and what their lives are about. Their access to social supports and material resources are often disrupted. Men's Sheds offer a space where retired men can actively pursue wellbeing, and respond to disruption and loneliness through emplaced community practices. This paper draws on ethnographic research in a Men's Shed in Auckland, New Zealand in order to explore the social practices through which men create a shared space for themselves in which they can engage in meaningful relationships with each other. We document how participants work in concert to create a space in which they can be together through collective labour. Their emplacement in the shed affords opportunities for supported transitions into retirement and for engaging healthy lives beyond paid employment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Phase space model for transmission of light beam

International Nuclear Information System (INIS)

Fu Shinian

1989-01-01

Based on Fermat's principle of ray optics, the Hamiltonian of an optical ray is derived by comparison with classical mechanics. A phase space model of light beam is proposed, assuming that the light beam, regarded as a group of rays, can be described by an ellipse in the μ-phase space. Therefore, the transmission of light beam is represented by the phase space matrix transformation. By means of this non-wave formulation, the same results are obtained as those from wave equation such as Kogelnik's ABCD law. As an example of the application on this model, the matching problem of optical cavity is solved

BPS submodels of the Skyrme model

Energy Technology Data Exchange (ETDEWEB)

Adam, C., E-mail: adam@fpaxp1.usc.es [Departamento de Física de Partículas, Universidad de Santiago de Compostela and Instituto Galego de Física de Altas Enerxias (IGFAE), E-15782 Santiago de Compostela (Spain); Sanchez-Guillen, J. [Departamento de Física de Partículas, Universidad de Santiago de Compostela and Instituto Galego de Física de Altas Enerxias (IGFAE), E-15782 Santiago de Compostela (Spain); Wereszczynski, A. [Institute of Physics, Jagiellonian University, Lojasiewicza 11, Kraków (Poland)

2017-06-10

We show that the standard Skyrme model without pion mass term can be expressed as a sum of two BPS submodels, i.e., of two models whose static field equations, independently, can be reduced to first order equations. Further, these first order (BPS) equations have nontrivial solutions, at least locally. These two submodels, however, cannot have common solutions. Our findings also shed some light on the rational map approximation. Finally, we consider certain generalisations of the BPS submodels.

Shedding light on the subject: introduction to illumination engineering and design for multidiscipline engineering students

Science.gov (United States)

Ronen, Ram S.; Smith, R. Frank

1995-10-01

Educating engineers and architects in Illumination Engineering and related subjects has become a very important field and a very satisfying and rewarding one. Main reasons include the need to significantly conserve lighting energy and meet government regulations while supplying appropriate light levels and achieving aesthetical requirements. The proliferation of new lamps, luminaries and lighting controllers many of which are 'energy savers' also helps a trend to seek help from lighting engineers when designing new commercial and residential buildings. That trend is believed to continue and grow as benefits become attractive and new government conservation regulations take affect. To make things even better one notices that Engineering and Science students in most disciplines make excellent candidates for Illumination Engineers because of their background and teaching them can move ahead at a brisk pace and be a rewarding experience nevertheless. In the past two years, Cal Poly Pomona College of Engineering has been the beneficiary of a DOE/California grant. Its purpose was to precipitate and oversee light curricula in various California community colleges and also develop and launch an Illumination Engineering minor at Cal Poly University. Both objectives have successfully been met. Numerous community colleges throughout California developed and are offering a sequence of six lighting courses leading to a certificate; the first graduating class is now coming out of both Cypress and Consumnes Community Colleges. At Cal Poly University a four course/laboratory sequence leading to a minor in Illumination Engineering (ILE) is now offered to upper division students in the College of Engineering, College of Science and College of Architecture and Design. The ILE sequence will briefly be described. The first course, Introduction to Illumination Engineering and its laboratory are described in more detail alter. Various methods of instruction including lectures, self work

The dynamics of EBV shedding implicate a central role for epithelial cells in amplifying viral output.

Directory of Open Access Journals (Sweden)

Vey Hadinoto

2009-07-01

Full Text Available To develop more detailed models of EBV persistence we have studied the dynamics of virus shedding in healthy carriers. We demonstrate that EBV shedding into saliva is continuous and rapid such that the virus level is replaced in < or =2 minutes, the average time that a normal individual swallows. Thus, the mouth is not a reservoir of virus but a conduit through which a continuous flow stream of virus passes in saliva. Consequently, virus is being shed at a much higher rate than previously thought, a level too high to be accounted for by replication in B cells in Waldeyer's ring alone. Virus shedding is relatively stable over short periods (hours-days but varies through 3.5 to 5.5 logs over longer periods, a degree of variation that also cannot be accounted for solely by replication in B cells. This variation means, contrary to what is generally believed, that the definition of high and low shedder is not so much a function of variation between individuals but within individuals over time. The dynamics of shedding describe a process governing virus production that is occurring independently < or =3 times at any moment. This process grows exponentially and is then randomly terminated. We propose that these dynamics are best explained by a model where single B cells sporadically release virus that infects anywhere from 1 to 5 epithelial cells. This infection spreads at a constant exponential rate and is terminated randomly, resulting in infected plaques of epithelial cells ranging in size from 1 to 10(5 cells. At any one time there are a very small number (< or =3 of plaques. We suggest that the final size of these plaques is a function of the rate of infectious spread within the lymphoepithelium which may be governed by the structural complexity of the tissue but is ultimately limited by the immune response.

The value of Autoimmune Syndrome Induced by Adjuvant (ASIA) - Shedding light on orphan diseases in autoimmunity.

Science.gov (United States)

Segal, Yahel; Dahan, Shani; Sharif, Kassem; Bragazzi, Nicola Luigi; Watad, Abdulla; Amital, Howard

2018-05-01

Autoimmune Syndrome Induced by Adjuvant (ASIA) is a definition aimed to describe the common etiological process at the root of five clinical entities sharing similar symptomatology: macrophagic myofasciitis syndrome (MMF), Gulf War Syndrome (GWS), sick building syndrome (SBS), siliconosis, and post vaccination autoimmune phenomena. ASIA illustrates the role of environmental immune stimulating agents, or adjuvants, in the instigation of complex autoimmune reactions among individuals bearing a genetic preponderance for autoimmunity. The value of ASIA lies first in the acknowledgment it provides for patients suffering from these as yet ill-defined medical conditions. Equally important is the spotlight it sheds for further research of these poorly understood conditions sharing a common pathogenesis. In this article we elaborate on the significance of ASIA, review the current evidence in support of the syndrome, and address recent reservations raised regarding its validity. Copyright © 2018 Elsevier B.V. All rights reserved.

On light dilaton extensions of the Standard Model

International Nuclear Information System (INIS)

Megías, Eugenio; Pujolàs, Oriol; Quirós, Mariano

2016-01-01

We discuss the presence of a light dilaton in Conformal Field Theories deformed by a single scalar operator, in the holographic realization consisting of confining Renormalization Group flows. Then, we apply this formalism to study the extension of the Standard Model with a light dilaton in a 5D warped model. We study the spectrum of scalar and vector perturbations, compare the model predictions with Electroweak Precision Tests and find the corresponding bounds for the lightest modes. Finally, we analyze the possibility that the Higgs resonance found at the LHC be a dilaton

Understanding the proton radius puzzle: Nuclear structure effects in light muonic atoms

Directory of Open Access Journals (Sweden)

Ji Chen

2016-01-01

Full Text Available We present calculations of nuclear structure effects to the Lamb shift in light muonic atoms. We adopt a modern ab-initio approach by combining state-of-the-art nuclear potentials with the hyperspherical harmonics method. Our calculations are instrumental to the determination of nuclear charge radii in the Lamb shift measurements, which will shed light on the proton radius puzzle.

A bankruptcy problem approach to load-shedding in multiagent-based microgrid operation.

Science.gov (United States)

Kim, Hak-Man; Kinoshita, Tetsuo; Lim, Yujin; Kim, Tai-Hoon

2010-01-01

A microgrid is composed of distributed power generation systems (DGs), distributed energy storage devices (DSs), and loads. To maintain a specific frequency in the islanded mode as an important requirement, the control of DGs' output and charge action of DSs are used in supply surplus conditions and load-shedding and discharge action of DSs are used in supply shortage conditions. Recently, multiagent systems for autonomous microgrid operation have been studied. Especially, load-shedding, which is intentional reduction of electricity use, is a critical problem in islanded microgrid operation based on the multiagent system. Therefore, effective schemes for load-shedding are required. Meanwhile, the bankruptcy problem deals with dividing short resources among multiple agents. In order to solve the bankruptcy problem, division rules, such as the constrained equal awards rule (CEA), the constrained equal losses rule (CEL), and the random arrival rule (RA), have been used. In this paper, we approach load-shedding as a bankruptcy problem. We compare load-shedding results by above-mentioned rules in islanded microgrid operation based on wireless sensor network (WSN) as the communication link for an agent's interactions.

Effects of ethanol on plasma protein shedding in the human stomach

International Nuclear Information System (INIS)

Brassinne, A.

1979-01-01

Plasma protein shedding in the stomach was measured in 23 normal individuals before and after intragastric administration of a 30% solution of ethyl alcohol. Two different methods were used to assess plasma protein shedding. The first technique utilizes [ 131 I] albumin and requires neutralization of the gastric juice. It was used in 12 subjects and failed to demonstrate any increase of plasma protein shedding under the influence of ethanol. The second technique which utilizes [ 51 Cr] chloride was used in 11 subjects. It demonstrated a significant increase of the gastric clearance of plasma protein which reached 2.5 times the control values. The [ 51 Cr] chloride technique does not require prior neutralization of gastric acidity. It is concluded that, in normal man, ethanol administration increases plasma protein shedding in the stomach when it is given in the presence of an acid gastric juice. The effect is not observed when the gastric acidity is neutralized

Light-front quantization of the sine-Gordon model

International Nuclear Information System (INIS)

Burkardt, M.

1993-01-01

It is shown how to modify the canonical light-front quantization of the (1+1)-dimensional sine-Gordon model such that the zero-mode problem of light-front quantization is avoided. The canonical sine-Gordon Lagrangian is replaced by an effective Lagrangian which does not lead to divergences as k + =(k 0 +k 1 )/ √2 →0. After canonically quantizing the effective Lagrangian, one obtains the effective light-front Hamiltonian which agrees with the naive light-front (LF) Hamiltonian, up to one additional renormalization. The spectrum of the effective LF Hamiltonian is determined using discrete light-cone quantization and agrees with results from equal-time quantization

Shedding light on the role of lipid flippases in the secretory pathway

DEFF Research Database (Denmark)

Lopez Marques, Rosa Laura

that these pumps serve important functions in vesicular traffic, their activities being required to support vesicle formation in the secretory and endocytic pathways. We are now aiming at determining the mechanism by which these ATPases function in vesicle biogenesis. For this purpose, we are using novel...... biophysical approaches based on giant vesicles and several advanced bioimaging methods. The limitations and future perspectives of these techniques for the characterization of lipid translocases will be discussed in the light of our recent results....

Affordable and personalized lighting using inverse modeling and virtual sensors

Science.gov (United States)

Basu, Chandrayee; Chen, Benjamin; Richards, Jacob; Dhinakaran, Aparna; Agogino, Alice; Martin, Rodney

2014-03-01

Wireless sensor networks (WSN) have great potential to enable personalized intelligent lighting systems while reducing building energy use by 50%-70%. As a result WSN systems are being increasingly integrated in state-ofart intelligent lighting systems. In the future these systems will enable participation of lighting loads as ancillary services. However, such systems can be expensive to install and lack the plug-and-play quality necessary for user-friendly commissioning. In this paper we present an integrated system of wireless sensor platforms and modeling software to enable affordable and user-friendly intelligent lighting. It requires ⇠ 60% fewer sensor deployments compared to current commercial systems. Reduction in sensor deployments has been achieved by optimally replacing the actual photo-sensors with real-time discrete predictive inverse models. Spatially sparse and clustered sub-hourly photo-sensor data captured by the WSN platforms are used to develop and validate a piece-wise linear regression of indoor light distribution. This deterministic data-driven model accounts for sky conditions and solar position. The optimal placement of photo-sensors is performed iteratively to achieve the best predictability of the light field desired for indoor lighting control. Using two weeks of daylight and artificial light training data acquired at the Sustainability Base at NASA Ames, the model was able to predict the light level at seven monitored workstations with 80%-95% accuracy. We estimate that 10% adoption of this intelligent wireless sensor system in commercial buildings could save 0.2-0.25 quads BTU of energy nationwide.

Neuroscience Meets Music Education: Exploring the Implications of Neural Processing Models on Music Education Practice

Science.gov (United States)

Collins, Anita

2013-01-01

Over the past two decades, neuroscientists have been fascinated by the way the brain processes music. Using new technologies, neuroscientists offer us a better understanding of the human brain's structures and functions. They have further proposed explanatory models for how the brain processes music. While these models shed light on how the…

Experimental Investigation of Vortex Shedding in High Reynolds Number Flow Over Compressor Blades in Cascade

National Research Council Canada - National Science Library

Lim, Choon

2003-01-01

.... Vortex shedding was determined to be a leading edge phenomenon as periodic shedding was only detected on the pressure side of the wake, The relationship between vortex shedding frequency and Reynolds...

Community-based Men's Sheds: promoting male health, wellbeing and social inclusion in an international context.

Science.gov (United States)

Cordier, Reinie; Wilson, Nathan J

2014-09-01

Males experience greater mortality and morbidity than females in most Western countries. The Australian and Irish National Male Health Policies aim to develop a framework to address this gendered health disparity. Men's Sheds have a distinct community development philosophy and are thus identified in both policies as an ideal location to address social isolation and positively impact the health and wellbeing of males who attend. The aim of this international cross-sectional survey was to gather information about Men's Sheds, the people who attend Men's Sheds, the activities at Men's Sheds, and the social and health dimensions of Men's Sheds. Results demonstrate that Men's Sheds are contributing a dual health and social role for a range of male subgroups. In particular, Men's Sheds have an outward social focus, supporting the social and mental health needs of men; health promotion and health literacy are key features of Men's Sheds. Men's Sheds have an important role to play in addressing the gendered health disparity that males face. They serve as an exemplar to health promotion professionals of a community development context where the aims of male health policy can be actualized as one part of a wider suite of global initiatives to reduce the gendered health disparity. © The Author (2013). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Persistent genital herpes simplex virus-2 shedding years following the first clinical episode.

Science.gov (United States)

Phipps, Warren; Saracino, Misty; Magaret, Amalia; Selke, Stacy; Remington, Mike; Huang, Meei-Li; Warren, Terri; Casper, Corey; Corey, Lawrence; Wald, Anna

2011-01-15

Patients with newly acquired genital herpes simplex virus 2 (HSV-2) infection have virus frequently detected at the genital mucosa. Rates of genital shedding initially decrease over time after infection, but data on long-term viral shedding are lacking. For this study, 377 healthy adults with history of symptomatic genital HSV-2 infection collected anogenital swabs for HSV-2 DNA polymerase chain reaction for at least 30 consecutive days. Time since first genital herpes episode was significantly associated with reduced genital shedding. Total HSV shedding occurred on 33.6% of days in participants <1 year, 20.6% in those 1-9 years, and 16.7% in those ≥10 years from first episode. Subclinical HSV shedding occurred on 26.2% of days among participants <1 year, 13.1% in those 1-9 years, and 9.3% in those ≥10 years from first episode. On days with HSV detection, mean quantity was 4.9 log₁₀ copies/mL for those <1 year, 4.7 log₁₀ copies/mL among those 1-9 years, and 4.6 log₁₀ copies/mL among those ≥10 years since first episode. Rates of total and subclinical HSV-2 shedding decrease after the first year following the initial clinical episode. However, viral shedding persists at high rates and copy numbers years after infection, and therefore may pose continued risk of HSV-2 transmission to sexual partners.

Virus and host-specific differences in oral human herpesvirus shedding kinetics among Ugandan women and children.

Science.gov (United States)

Matrajt, Laura; Gantt, Soren; Mayer, Bryan T; Krantz, Elizabeth M; Orem, Jackson; Wald, Anna; Corey, Lawrence; Schiffer, Joshua T; Casper, Corey

2017-10-12

Human herpesviruses (HHV) establish lifelong latent infection and are transmitted primarily via shedding at mucosal surfaces. Each HHV causes a unique spectrum of disease depending on the infected individual's age and immunity. We collected weekly oral swabs from young children and mothers in 32 Ugandan households for a median of one year. We characterized kinetics of oral shedding during primary and chronic infection for each virus. Cytomegalovirus (CMV), Epstein-Barr virus (EBV), and HHV-6 were shed at high rates following primary infection. The rate of oral herpes simplex virus (HSV) shedding was lower overall, and children and mothers with chronic HSV infection had lower shedding rates than children with primary infection. CMV shedding rate and viral load were higher in children with primary infection compared to children with chronic infection, and even lower in mothers with chronic infection. HHV-6 shedding rate and viral load were similar between children with primary or chronic infection, but lower in mothers. EBV shedding rate and quantity decreased less dramatically in mothers versus children, with HIV-positive mothers shedding at a higher rate than HIV-negative mothers. Each HHV has a distinct pattern of oral shedding which depends partially on the age and immune status of the host.

BPS submodels of the Skyrme model

Directory of Open Access Journals (Sweden)

C. Adam

2017-06-01

Full Text Available We show that the standard Skyrme model without pion mass term can be expressed as a sum of two BPS submodels, i.e., of two models whose static field equations, independently, can be reduced to first order equations. Further, these first order (BPS equations have nontrivial solutions, at least locally. These two submodels, however, cannot have common solutions. Our findings also shed some light on the rational map approximation. Finally, we consider certain generalisations of the BPS submodels.

Reaction times to weak test lights. [psychophysics biological model

Science.gov (United States)

Wandell, B. A.; Ahumada, P.; Welsh, D.

1984-01-01

Maloney and Wandell (1984) describe a model of the response of a single visual channel to weak test lights. The initial channel response is a linearly filtered version of the stimulus. The filter output is randomly sampled over time. Each time a sample occurs there is some probability increasing with the magnitude of the sampled response - that a discrete detection event is generated. Maloney and Wandell derive the statistics of the detection events. In this paper a test is conducted of the hypothesis that the reaction time responses to the presence of a weak test light are initiated at the first detection event. This makes it possible to extend the application of the model to lights that are slightly above threshold, but still within the linear operating range of the visual system. A parameter-free prediction of the model proposed by Maloney and Wandell for lights detected by this statistic is tested. The data are in agreement with the prediction.

A Bankruptcy Problem Approach to Load-shedding in Multiagent-based Microgrid Operation

Directory of Open Access Journals (Sweden)

Yujin Lim

2010-09-01

Full Text Available A microgrid is composed of distributed power generation systems (DGs, distributed energy storage devices (DSs, and loads. To maintain a specific frequency in the islanded mode as an important requirement,  the control of DGs’ output and charge action of DSs are used in supply surplus conditions and load-shedding and discharge action of DSs are used in supply shortage conditions. Recently, multiagent systems for autonomous microgrid operation have been studied. Especially, load-shedding, which is intentional reduction of electricity use, is a critical problem in islanded microgrid operation based on the multiagent system. Therefore, effective schemes for load-shedding are required. Meanwhile, the bankruptcy problem deals with dividing short resources among multiple agents. In order to solve the bankruptcy problem, division rules, such as the constrained equal awards rule (CEA, the constrained equal losses rule (CEL, and the random arrival rule (RA, have been used. In this paper, we approach load-shedding as a bankruptcy problem. We compare load-shedding results by above-mentioned rules in islanded microgrid operation based on wireless sensor network (WSN as the communication link for an agent’s interactions.

Wake shed by an accelerating carangiform fish

Science.gov (United States)

Ting, Shang-Chieh; Yang, Jing-Tang

2008-11-01

We reveal an important fact that momentum change observed in the wake of an accelerating carangiform fish does not necessarily elucidate orientations of propulsive forces produced. An accelerating Crucian Carp (Carassius auratus) was found to shed a wake with net forward fluid momentum, which seemed drag-producing. Based on Newton's law, however, an accelerating fish is expected to shed a thrust wake with net rearward fluid momentum, rather than a drag wake. The unusual wake pattern observed is considered to be resulted primarily from the effect of pressure gradient created by accelerating movements of the fish. Ambient fluids tend to be sucked into low pressure zones behind an accelerating fish, resulting in forward orientations of jets recognizable in the wake. Accordingly, as to an accelerating fish, identifying force orientations from the wake requires considering also the effect of pressure gradient.

Reduction of Salmonella Shedding by Sows during Gestation in Relation to Its Fecal Microbiome

Directory of Open Access Journals (Sweden)

Guillaume Larivière-Gauthier

2017-11-01

Full Text Available Pork meat is estimated to be responsible for 10–20% of human salmonellosis cases in Europe. Control strategies at the farm could reduce contamination at the slaughterhouse. One of the targeted sectors of production is maternity, where sows could be Salmonella reservoirs. The aim of this study was to assess the dynamics of shedding of Salmonella in terms of variation in both shedding prevalence and strains excreted during gestation in Quebec’s maternity sector. The evolution of the fecal microbiota of these sows during gestation was also assessed to detect bacterial populations associated with these variations. A total of 73 sows both at the beginning and the end of the gestation were randomly selected and their fecal matter was analyzed. Salmonella detection was conducted using a method that includes two selective enrichment media (MSRV and TBG. Nine isolates per positive samples were collected. Among the 73 sows tested, 27 were shedding Salmonella. Sows in the first third of their gestation shed Salmonella significantly more frequently (21/27 than those in the last third (6/46 (χ2P < 0.05. The shedding status of 19 of the sows that were previously sampled in the first third of their gestation was followed, this time in the last third of their gestation, which confirmed reduction of shedding. Using 16S rRNA gene sequencing and qPCR, significant differences between the fecal flora of sows at the beginning and the end of the gestation, shedding Salmonella or not and with different parity number were detected. Using MaAsLin, multiple OTUs were found to be associated with the time of gestation, the status of Salmonella excretion and parity number. Some of the identified taxa could be linked to the reduction of the shedding of Salmonella at the end of gestation. In this study, we showed that the level of Salmonella shedding was variable during gestation with significantly higher shedding at the beginning rather than at the end of gestation. We

Implementation of a Dynamic Mooring Solver (MOODY) into a wave to wire model of a simple WEC

DEFF Research Database (Denmark)

Ferri, Francesco; Palm, Johannes

This report forms the deliverable D4.6 of the Structural Design of Wave Energy Devices (SDWED) project. The main objective of the report is to shed light on the implementation of a simple floating wave energy converter (fWEC) numerical model coupled with a dynamic model of the reaction system. Th...

Zika Virus Shedding in Semen of Symptomatic Infected Men.

Science.gov (United States)

Mead, Paul S; Duggal, Nisha K; Hook, Sarah A; Delorey, Mark; Fischer, Marc; Olzenak McGuire, Dana; Becksted, Heidi; Max, Ryan J; Anishchenko, Michael; Schwartz, Amy M; Tzeng, Wen-Pin; Nelson, Christina A; McDonald, Erin M; Brooks, John T; Brault, Aaron C; Hinckley, Alison F

2018-04-12

Zika virus (ZIKV) is an emerging mosquito-borne flavivirus that has been linked to adverse birth outcomes. Previous reports have shown that person-to-person transmission can occur by means of sexual contact. We conducted a prospective study involving men with symptomatic ZIKV infection to determine the frequency and duration of ZIKV shedding in semen and urine and to identify risk factors for prolonged shedding in these fluids. Specimens were obtained twice per month for 6 months after illness onset and were tested by real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay for ZIKV RNA and by Vero cell culture and plaque assay for infectious ZIKV. A total of 1327 semen samples from 184 men and 1038 urine samples from 183 men were obtained 14 to 304 days after illness onset. ZIKV RNA was detected in the urine of 7 men (4%) and in the semen of 60 (33%), including in semen samples from 22 of 36 men (61%) who were tested within 30 days after illness onset. ZIKV RNA shedding in semen decreased substantially during the 3 months after illness onset but continued for 281 days in 1 man (1%). Factors that were independently associated with prolonged RNA shedding included older age, less frequent ejaculation, and the presence of certain symptoms at the time of initial illness. Infectious ZIKV was isolated from 3 of 78 semen samples with detectable ZIKV RNA, all obtained within 30 days after illness onset and all with at least 7.0 log 10 ZIKV RNA copies per milliliter of semen. ZIKV RNA was commonly present in the semen of men with symptomatic ZIKV infection and persisted in some men for more than 6 months. In contrast, shedding of infectious ZIKV appeared to be much less common and was limited to the first few weeks after illness onset. (Funded by the Centers for Disease Control and Prevention.).

Measuring, modeling and mapping ecosystem services in the Eastern Arc Mountains of Tanzania

DEFF Research Database (Denmark)

Fisher, B.; Turner, R. K.; Burgess, Neil David

2011-01-01

sourced data, data-driven models, and socio-economic scenarios coupled with rule-based assumptions. Here we describe the construction of this spatial information and how it can help to shed light on the complex relationships between ecological and social systems. There are obvious difficulties......In light of the significance that ecosystem service research is likely to play in linking conservation activities and human welfare, systematic approaches to measuring, modeling and mapping ecosystem services (and their value to society) are sorely needed. In this paper we outline one such approach...

Measurement on the cavitating vortex shedding behind rectangular obstacles

International Nuclear Information System (INIS)

Hegedus, F; Hos, C; Pandula, Z; Kullmann, L

2010-01-01

Measurement results on the cavitating vortex shedding behind sharp-edged rectangular bodies are presented, intended to provide benchmark cases for the validation of unsteady cavitation models of CFD codes. Rectangular bodies of increasing aspect ratio (1, 2, 3 and 4) were used with a constant 25mm height (12.5% blockage ratio). The water velocity in the 0.2x0.05m test section of the channel was varied between 1 and 12 m/s resulting in a Reynolds number in the range of (0.4-3.5)x105. Pressure signals were measured at several locations, notably in the wake. Dominant frequencies and Strouhal numbers are reported from cavitation-free flow (classic von Karman vortex shedding) up to supercavitation as a function of the free-stream Reynolds number. The results are in good agreement with the literature in case of the square cylinder. We experienced a slight increase of the dominant Strouhal number with increasing aspect ratio. This result is somewhat inconsistent with the literature, in which a fall of the Strouhal number can be observed at side ratio 2. This may be the consequence of the different ranges of Reynolds numbers. It was also found that between the inception of cavitation and the formation of supercavitation the Strouhal number is not affected by cavitation.

Measurement on the cavitating vortex shedding behind rectangular obstacles

Energy Technology Data Exchange (ETDEWEB)

Hegedus, F; Hos, C; Pandula, Z; Kullmann, L, E-mail: hegedusf@hds.bme.h [Department of Hydrodynamic Systems, Budapest University of Technology and Economics Muegyetem rkp. 1, Budapest 1111 (Hungary)

2010-08-15

Measurement results on the cavitating vortex shedding behind sharp-edged rectangular bodies are presented, intended to provide benchmark cases for the validation of unsteady cavitation models of CFD codes. Rectangular bodies of increasing aspect ratio (1, 2, 3 and 4) were used with a constant 25mm height (12.5% blockage ratio). The water velocity in the 0.2x0.05m test section of the channel was varied between 1 and 12 m/s resulting in a Reynolds number in the range of (0.4-3.5)x105. Pressure signals were measured at several locations, notably in the wake. Dominant frequencies and Strouhal numbers are reported from cavitation-free flow (classic von Karman vortex shedding) up to supercavitation as a function of the free-stream Reynolds number. The results are in good agreement with the literature in case of the square cylinder. We experienced a slight increase of the dominant Strouhal number with increasing aspect ratio. This result is somewhat inconsistent with the literature, in which a fall of the Strouhal number can be observed at side ratio 2. This may be the consequence of the different ranges of Reynolds numbers. It was also found that between the inception of cavitation and the formation of supercavitation the Strouhal number is not affected by cavitation.

Information report published in application of the article 145 of the rule by the Commission on economic affairs on stakes and impacts of distributed load shedding. Nr 3690

International Nuclear Information System (INIS)

Battistel, Marie-Noelle

2016-01-01

Distributed load shedding is a complex issue with actual stakes for public policy: a constrained context for public finances, and necessity to use public money in an optimal and efficient way. Even though load shedding has a positive impact on the environment, its business model presents important weaknesses and cannot survive without public subsidy. This report addresses these issues, and first defines load shedding, states the reasons for supporting distributed load shedding, discusses how the French arrangement for the valorisation of load shedding is ambitious and innovative. It also outlines and discusses the present difficulties faced by load shedding, that it could become in the future an actual lever for energy transition. The authors then examine what public authorities could do regarding the payment of load shedding by the operator to the provider, regarding returns on experience and other solutions on the short term, and regarding the promotion of innovative means of distributed load shedding which would be focused on consumers

Modeling of photoluminescence in laser-based lighting systems

Science.gov (United States)

Chatzizyrli, Elisavet; Tinne, Nadine; Lachmayer, Roland; Neumann, Jörg; Kracht, Dietmar

2017-12-01

The development of laser-based lighting systems has been the latest step towards a revolution in illumination technology brought about by solid-state lighting. Laser-activated remote phosphor systems produce white light sources with significantly higher luminance than LEDs. The weak point of such systems is often considered to be the conversion element. The high-intensity exciting laser beam in combination with the limited thermal conductivity of ceramic phosphor materials leads to thermal quenching, the phenomenon in which the emission efficiency decreases as temperature rises. For this reason, the aim of the presented study is the modeling of remote phosphor systems in order to investigate their thermal limitations and to calculate the parameters for optimizing the efficiency of such systems. The common approach to simulate remote phosphor systems utilizes a combination of different tools such as ray tracing algorithms and wave optics tools for describing the incident and converted light, whereas the modeling of the conversion process itself, i.e. photoluminescence, in most cases is circumvented by using the absorption and emission spectra of the phosphor material. In this study, we describe the processes involved in luminescence quantum-mechanically using the single-configurational-coordinate diagram as well as the Franck-Condon principle and propose a simulation model that incorporates the temperature dependence of these processes. Following an increasing awareness of climate change and environmental issues, the development of ecologically friendly lighting systems featuring low power consumption and high luminous efficiency is imperative more than ever. The better understanding of laser-based lighting systems is an important step towards that aim as they may improve on LEDs in the near future.

Predicted protein interactions of IFITMs may shed light on mechanisms of Zika virus-induced microcephaly and host invasion [version 2; referees: 2 approved, 1 approved with reservations, 1 not approved

Directory of Open Access Journals (Sweden)

Madhavi K. Ganapathiraju

2017-11-01

Full Text Available After the first reported case of Zika virus (ZIKV in Brazil, in 2015, a significant increase in the reported cases of microcephaly was observed. Microcephaly is a neurological condition in which the infant’s head is significantly smaller with complications in brain development. Recently, two small membrane-associated interferon-inducible transmembrane proteins (IFITM1 and IFITM3 have been shown to repress members of the flaviviridae family which includes ZIKV. However, the exact mechanisms leading to the inhibition of the virus are yet unknown. Here, we assembled an interactome of IFITM1 and IFITM3 with known protein-protein interactions (PPIs collected from publicly available databases and novel PPIs predicted using the High-confidence Protein-Protein Interaction Prediction (HiPPIP model. We analyzed the functional and pathway associations of the interacting proteins, and found that there are several immunity pathways (toll-like receptor signaling, cd28 signaling in T-helper cells, crosstalk between dendritic cells and natural killer cells, neuronal pathways (axonal guidance signaling, neural tube closure and actin cytoskeleton signaling and developmental pathways (neural tube closure, embryonic skeletal system development that are associated with these interactors. Our novel PPIs associate cilia dysfunction in ependymal cells to microcephaly, and may also shed light on potential targets of ZIKV for host invasion by immunosuppression and cytoskeletal rearrangements. These results could help direct future research in elucidating the mechanisms underlying host defense to ZIKV and other flaviviruses.

Hot-Wire Calibration at Low Velocities: Revisiting the Vortex Shedding Method

Directory of Open Access Journals (Sweden)

Sohrab S. Sattarzadeh

2013-01-01

Full Text Available The necessity to calibrate hot-wire probes against a known velocity causes problems at low velocities, due to the inherent inaccuracy of pressure transducers at low differential pressures. The vortex shedding calibration method is in this respect a recommended technique to obtain calibration data at low velocities, due to its simplicity and accuracy. However, it has mainly been applied in a low and narrow Reynolds number range known as the laminar vortex shedding regime. Here, on the other hand, we propose to utilize the irregular vortex shedding regime and show where the probe needs to be placed with respect to the cylinder in order to obtain unambiguous calibration data.

Research on light rail electric load forecasting based on ARMA model

Science.gov (United States)

Huang, Yifan

2018-04-01

The article compares a variety of time series models and combines the characteristics of power load forecasting. Then, a light load forecasting model based on ARMA model is established. Based on this model, a light rail system is forecasted. The prediction results show that the accuracy of the model prediction is high.

Penggunaan Elaboration Likelihood Model dalam Menganalisis Penerimaan Teknologi Informasi

OpenAIRE

vitrian, vitrian2

2010-01-01

This article discusses some technology acceptance models in an organization. Thorough analysis of how technology is acceptable help managers make any planning to implement new teachnology and make sure that new technology could enhance organization's performance. Elaboration Likelihood Model (ELM) is the one which sheds light on some behavioral factors in acceptance of information technology. The basic tenet of ELM states that human behavior in principle can be influenced through central r...

Beyond Knut Holt's fusion model, balancing market pull and technology push

NARCIS (Netherlands)

Nagel, A.P.

2003-01-01

Should a firm rely on market pull or on technology push? Some scholars have extreme opinions on this and firms do switch emphasis on push and pull over time. Knut Holt, the first president of ISPIM, presented his so-called Fusion Model in the early 1970s to shed light onto this debate. This paper

Current state and future perspectives on coupled ice-sheet – sea-level modelling

NARCIS (Netherlands)

de Boer, Bas; Stocchi, Paolo; Whitehouse, Pippa L.; van de Wal, Roderik S.W.

2017-01-01

The interaction between ice-sheet growth and retreat and sea-level change has been an established field of research for many years. However, recent advances in numerical modelling have shed new light on the precise interaction of marine ice sheets with the change in near-field sea level, and the

The Elaboration Likelihood Model and Proxemic Violations as Peripheral Cues to Information Processing.

Science.gov (United States)

Eaves, Michael

This paper provides a literature review of the elaboration likelihood model (ELM) as applied in persuasion. Specifically, the paper addresses distraction with regard to effects on persuasion. In addition, the application of proxemic violations as peripheral cues in message processing is discussed. Finally, the paper proposes to shed new light on…

Modeling of an Adjustable Beam Solid State Light

Data.gov (United States)

National Aeronautics and Space Administration — This proposal is for the development of a computational model of a prototype variable beam light source using optical modeling software, Zemax OpticStudio ®. The...

Secretome analysis to elucidate metalloprotease-dependent ectodomain shedding of glycoproteins during neuronal differentiation.

Science.gov (United States)

Tsumagari, Kazuya; Shirakabe, Kyoko; Ogura, Mayu; Sato, Fuminori; Ishihama, Yasushi; Sehara-Fujisawa, Atsuko

2017-02-01

Many membrane proteins are subjected to limited proteolyses at their juxtamembrane regions, processes referred to as ectodomain shedding. Shedding ectodomains of membrane-bound ligands results in activation of downstream signaling pathways, whereas shedding those of cell adhesion molecules causes loss of cell-cell contacts. Secreted proteomics (secretomics) using high-resolution mass spectrometry would be strong tools for both comprehensive identification and quantitative measurement of membrane proteins that undergo ectodomain shedding. In this study, to elucidate the ectodomain shedding events that occur during neuronal differentiation, we establish a strategy for quantitative secretomics of glycoproteins released from differentiating neuroblastoma cells into culture medium with or without GM6001, a broad-spectrum metalloprotease inhibitor. Considering that most of transmembrane and secreted proteins are N-glycosylated, we include a process of N-glycosylated peptides enrichment as well as isotope tagging in our secretomics workflow. Our results show that differentiating N1E-115 neurons secrete numerous glycosylated polypeptides in metalloprotease-dependent manners. They are derived from cell adhesion molecules such as NCAM1, CADM1, L1CAM, various transporters and receptor proteins. These results show the landscape of ectodomain shedding and other secretory events in differentiating neurons and/or during axon elongation, which should help elucidate the mechanism of neurogenesis and the pathogenesis of neurological disorders. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

Faecal Campylobacter shedding among dogs in animal shelters across Texas.

Science.gov (United States)

Leahy, A M; Cummings, K J; Rodriguez-Rivera, L D; Hamer, S A; Lawhon, S D

2017-12-01

Epidemiologic studies on faecal Campylobacter shedding among dogs in the United States have been limited, despite evidence that the incidence of human campylobacteriosis has increased over the last decade. Our objectives were to estimate the prevalence of faecal Campylobacter shedding among shelter dogs in Texas, to estimate the specific prevalence of Campylobacter jejuni and Campylobacter coli shedding, and to identify risk factors for Campylobacter-positive status. Using a cross-sectional study design, we collected faecal samples from dogs in six animal shelters across Texas between May and December, 2014. Quantitative PCR protocols were used to detect Campylobacter in samples and to specifically identify C. jejuni and C. coli. The prevalence of faecal Campylobacter shedding among sampled dogs was 75.7% (140/185). Prevalence varied significantly by shelter (p = .03), ranging from 57% to 93%. There was a marginal association (p = .06) between abnormal faecal consistency and positive Campylobacter status, after controlling for shelter as a random effect. However, approximately 70% of Campylobacter-positive dogs had grossly normal faeces. Campylobacter prevalence did not vary significantly by age group or sex. The prevalence of C. jejuni-positive samples was 5.4% (10/185), but C. coli was not detected in any samples. Dogs are a potential source of zoonotic Campylobacter transmission. © 2017 Blackwell Verlag GmbH.

Reinfusion of Shed Blood Following Pediatric Orthopaedic Surgery

National Research Council Canada - National Science Library

Blevins, Field

1991-01-01

.... The use of a system for salvage and reinfusion of nonwashed shed blood postoperatively is recommended as a safe method to minimize the need for homologous transfusion, especially when there is...

Hjemløshed i Danmark 2011

DEFF Research Database (Denmark)

Lauritzen, Heidi Hesselberg; Boje-Kovacs, Bence; Benjaminsen, Lars

Rapporten fremlægger resultaterne af den tredje nationale kortlægning af hjemløshed i Danmark og giver et ajourført billede af omfanget og karakteren af hjemløsheden. Ligesom i de to forrige optællinger blev der i kortlægningsugen (uge 6) registreret ca. 5.000 hjemløse. Sammensætningen af gruppen...

Particle shedding from peristaltic pump tubing in biopharmaceutical drug product manufacturing.

Science.gov (United States)

Saller, Verena; Matilainen, Julia; Grauschopf, Ulla; Bechtold-Peters, Karoline; Mahler, Hanns-Christian; Friess, Wolfgang

2015-04-01

In a typical manufacturing setup for biopharmaceutical drug products, the fill and dosing pump is placed after the final sterile filtration unit in order to ensure adequate dispensing accuracy and avoid backpressure peaks. Given the sensitivity of protein molecules, peristaltic pumps are often preferred over piston pumps. However, particles may be shed from the silicone tubing employed. In this study, particle shedding and a potential turbidity increase during peristaltic pumping of water and buffer were investigated using three types of commercially available silicone tubing. In the recirculates, mainly particles of around 200 nm next to a very small fraction of particles in the lower micrometer range were found. Using 3D laser scanning microscopy, surface roughness of the inner tubing surface was found to be a determining factor for particle shedding from silicone tubing. As the propensity toward particle shedding varied between tubing types and also cannot be concluded from manufacturer's specifications, individual testing with the presented methods is recommended during tubing qualification. Choosing low abrasive tubing can help to further minimize the very low particle counts to be expected in pharmaceutical drug products. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

AutoLens: Automated Modeling of a Strong Lens's Light, Mass and Source

Science.gov (United States)

Nightingale, J. W.; Dye, S.; Massey, Richard J.

2018-05-01

This work presents AutoLens, the first entirely automated modeling suite for the analysis of galaxy-scale strong gravitational lenses. AutoLens simultaneously models the lens galaxy's light and mass whilst reconstructing the extended source galaxy on an adaptive pixel-grid. The method's approach to source-plane discretization is amorphous, adapting its clustering and regularization to the intrinsic properties of the lensed source. The lens's light is fitted using a superposition of Sersic functions, allowing AutoLens to cleanly deblend its light from the source. Single component mass models representing the lens's total mass density profile are demonstrated, which in conjunction with light modeling can detect central images using a centrally cored profile. Decomposed mass modeling is also shown, which can fully decouple a lens's light and dark matter and determine whether the two component are geometrically aligned. The complexity of the light and mass models are automatically chosen via Bayesian model comparison. These steps form AutoLens's automated analysis pipeline, such that all results in this work are generated without any user-intervention. This is rigorously tested on a large suite of simulated images, assessing its performance on a broad range of lens profiles, source morphologies and lensing geometries. The method's performance is excellent, with accurate light, mass and source profiles inferred for data sets representative of both existing Hubble imaging and future Euclid wide-field observations.

Modeling repetitive motions using structured light.

Science.gov (United States)

Xu, Yi; Aliaga, Daniel G

2010-01-01

Obtaining models of dynamic 3D objects is an important part of content generation for computer graphics. Numerous methods have been extended from static scenarios to model dynamic scenes. If the states or poses of the dynamic object repeat often during a sequence (but not necessarily periodically), we call such a repetitive motion. There are many objects, such as toys, machines, and humans, undergoing repetitive motions. Our key observation is that when a motion-state repeats, we can sample the scene under the same motion state again but using a different set of parameters; thus, providing more information of each motion state. This enables robustly acquiring dense 3D information difficult for objects with repetitive motions using only simple hardware. After the motion sequence, we group temporally disjoint observations of the same motion state together and produce a smooth space-time reconstruction of the scene. Effectively, the dynamic scene modeling problem is converted to a series of static scene reconstructions, which are easier to tackle. The varying sampling parameters can be, for example, structured-light patterns, illumination directions, and viewpoints resulting in different modeling techniques. Based on this observation, we present an image-based motion-state framework and demonstrate our paradigm using either a synchronized or an unsynchronized structured-light acquisition method.

Pedagogical Catalysts of Civic Competence: The Development of a Critical Epistemological Model for Community-Based Learning

Science.gov (United States)

Stokamer, Stephanie

2013-01-01

Democratic problem-solving necessitates an active and informed citizenry, but existing research on service-learning has shed little light on the relationship between pedagogical practices and civic competence outcomes. This study developed and tested a model to represent that relationship and identified pedagogical catalysts of civic competence…

Turbulence theories and modelling of fluids and plasmas

Energy Technology Data Exchange (ETDEWEB)

Yoshizawa, Akira; Yokoi, Nobumitsu [Institute of Industrial Science, Univ. of Tokyo, Tokyo (Japan); Itoh, Sanae-I. [Research Institute for Applied Mechanics, Kyushu Univ., Kasuga, Fukuoka (Japan); Itoh, Kimitaka [National Inst. for Fusion Science, Toki, Gifu (Japan)

2001-04-01

Theoretical and heuristic modelling methods are reviewed for studying turbulence phenomena of fluids and plasmas. Emphasis is put on understanding of effects on turbulent characteristics due to inhomogeneities of field and plasma parameters. The similarity and dissimilarity between the methods for fluids and plasmas are sought in order to shed light on the properties that are shared or not by fluid and plasma turbulence. (author)

The Standard Model and the neutron beta-decay

CERN Document Server

Abele, H

2000-01-01

This article reviews the relationship between the observables in neutron beta-decay and the accepted modern theory of particle physics known as the Standard Model. Recent neutron-decay measurements of various mixed American-British-French-German-Russian collaborations try to shed light on the following topics: the coupling strength of charged weak currents, the universality of the electroweak interaction and the origin of parity violation.

The effect of structural motifs on the ectodomain shedding of human angiotensin-converting enzyme.

Science.gov (United States)

Conrad, Nailah; Schwager, Sylva L U; Carmona, Adriana K; Sturrock, Edward D

2016-12-02

Somatic angiotensin converting enzyme (sACE) is comprised of two homologous domains (N and C domains), whereas the smaller germinal isoform (tACE) is identical to the C domain. Both isozymes share an identical stalk, transmembrane and cytoplasmic domain, and undergo ectodomain shedding by an as yet unknown protease. Here we present evidence for the role of regions distal and proximal to the cleavage site in human ACE shedding. First, because of intrinsic differences between the N and C domains, discrete secondary structures (α-helix 7 and 8) on the surface of tACE were replaced with their N domain counterparts. Surprisingly, neither α-helix 7 nor α-helix 8 proved to be an absolute requirement for shedding. In the proximal ectodomain of tACE residues H 610 -L 614 were mutated to alanines and this resulted in a decrease in ACE shedding. An N-terminal extension of this mutation caused a reduction in cellular ACE activity. More importantly, it affected the processing of the protein to the membrane, resulting in expression of an underglycosylated form of ACE. When E 608 -H 614 was mutated to the homologous region of the N domain, processing was normal and shedding only moderately decreased suggesting that this region is more crucial for the processing of ACE than it is for regulating shedding. Finally, to determine whether glycosylation of the asparagine proximal to the Pro1199-Leu polymorphism in sACE affected shedding, the equivalent P 623 L mutation in tACE was investigated. The P 623 L tACE mutant showed an increase in shedding and MALDI MS analysis of a tryptic digest indicated that N 620 WT was glycosylated. The absence of an N-linked glycan at N 620 , resulted in an even greater increase in shedding. Thus, the conformational flexibility that the leucine confers to the stalk, is increased by the lack of glycosylation reducing access of the sheddase to the cleavage site. Copyright © 2016 Elsevier Inc. All rights reserved.

Load function modelling for light impact

International Nuclear Information System (INIS)

Klingmueller, O.

1982-01-01

For Pile Integrity Testing light weight drop hammers are used to induce stress waves. In the computational analysis of one-dimensional wave propagation a load function has to be used. Several mechanical models and corresponding load functions are discussed. It is shown that a bell-shaped function which does not correspond to a mechanical model is in best accordance with test results and does not lead to numerical disturbances in the computational results. (orig.) [de

Genital HSV Shedding among Kenyan Women Initiating Antiretroviral Therapy.

Directory of Open Access Journals (Sweden)

Griffins O Manguro

Full Text Available Genital ulcer disease (GUD prevalence increases in the first month of antiretroviral treatment (ART, followed by a return to baseline prevalence by month 3. Since most GUD is caused by herpes simplex virus type 2 (HSV-2, we hypothesized that genital HSV detection would follow a similar pattern after treatment initiation.We conducted a prospective cohort study of 122 HSV-2 and HIV-1 co-infected women with advanced HIV disease who initiated ART and were followed closely with collection of genital swab specimens for the first three months of treatment.At baseline, the HSV detection rate was 32%, without significant increase in genital HSV detection noted during the first month or the third month of ART. HIV-1 shedding declined during this period; no association was also noted between HSV and HIV-1 shedding during this period.Because other studies have reported increased HSV detection in women initiating ART and we have previously reported an increase in GUD during early ART, it may be prudent to counsel HIV-1 infected women initiating ART that HSV shedding in the genital tract may continue after ART initiation.

Solar lighting system delivery models for rural areas in developing countries

Energy Technology Data Exchange (ETDEWEB)

Koirala, Binod Prasad; Ortiz, Brisa [Freiburg Univ. (DE). Center for Renewable Energy (ZEE); Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany); Modi, Anish [KTH Royal Inst. of Technology, Stockholm (Sweden); Mathur, Jyotirmay [Malaviya National Institute of Technology, Jaipur (India); Kafle, Nashib [Alternative Energy Promotion Center (AEPC), Kathmandu (Nepal)

2011-07-01

Many rural areas in developing countries will not have electricity access from the central grid for several years to come. Autonomous Solar Lighting Systems (SLS) are attractive and enviromentally friendly options for replacing kerosene lamps and providing basic lighting services to such areas. In order to highlight the benefits of these technologies, analysis of reduction in indoor air pollution due to replacement of kerosene lamp by SLS has been carried out. Use of SLS in place of kerosene lamps saves an equivalent of 1341 kg CO{sub 2} emissions per annum from each household. If a suitable mechanism is created, this amount of GHG emissions saving could alone be sufficient to finance solar lighting system for rural households. However, these technologies have not reached most of the poor population. In order to guarantee the access of solar lighting to the people at the Base of the Pyramid (BOP), strengths of different organizations working in the rural areas should be combined together to form successful business models. This paper will discuss business models to disseminate such services to needy people. A comparative study of SLS delivery models based on cash, credit, leasing, subsidy and service is performed. In addition, SWOT analysis for each model is employed. Further, Case studies of few projects to elaborate different models are also presented. If suitable business models for its delivery to rural people are considered, solar lighting systems are viable for providing basic lighting needs of rural areas in developing countries. (orig.)

CAD Instructor Designs Eco-Friendly Shed

Science.gov (United States)

Schwendau, Mark

2013-01-01

Dissatisfied with the options offered by big box stores--and wanting to save some money and go as green as possible--the author puts his design and construction skills to good use. In this article, he shares how he designed and built an eco-friendly shed. He says he is very pleased with the results of working with his own design, reducing waste,…

[Blood conservation effect and safety of shed mediastinal blood autotransfusion after cardiac surgery].

Science.gov (United States)

Komiya, T; Ban, K; Yamazaki, K; Date, O; Nakamura, T; Kanzaki, Y

1998-10-01

Autotransfusion of shed mediastinal blood after cardiac surgery has been used to reduce risks related to homologous blood transfusions. To document the efficacy and safety of autotransfusion, we compared clinical findings of 80 patients receiving shed mediastinal blood (autotransfusion group) with those of the control group of 52 patients. The amount of the autotransfusion was limited to 800 ml, given the potentially harmful effects of shed blood transfusion. The mean transfused shed volume was 314 +/- 236 ml (S.D.). The serum levels of FDP-E, D-dimer and TAT after autotransfusion were higher in the autotransfusion group than in the control group (p = 0.01, p = 0.0004, p = 0.001, respectively). However, postoperative blood loss and the rate of reexploration for bleeding were similar in the two groups. The patients receiving blood products were fewer in the autotransfusion group than those in the control group (21% vs 44%; p = 0.005). Autotransfusion did not increase postoperative complications, including infection. Thus, although autotransfusion of mediastinal shed blood has the potential to affect hemostasis, unless the amount of autotransfusion exceeds 800 ml, it appears that this method is clinically safe and effective as a mean of blood conservation.

Leaf life span plasticity in tropical seedlings grown under contrasting light regimes

OpenAIRE

Vincent, Grégoire

2006-01-01

Background and Aims The phenotypic plasticity of leaf life span in response to low resource conditions has a potentially large impact on the plant carbon budget, notably in evergreen species not subject to seasonal leaf shedding, but has rarely been well documented. This study evaluates the plasticity of leaf longevity, in terms of its quantitative importance to the plant carbon balance under limiting light. Methods Seedlings of four tropical tree species with contrasting light requirements (...

Efficacy of N-methanocarbathymidine against genital herpes simplex virus type 2 shedding and infection in guinea pigs.

Science.gov (United States)

Bernstein, David I; Bravo, Fernando J; Pullum, Derek A; Shen, Hui; Wang, Mei; Rahman, Aquilur; Glazer, Robert I; Cardin, Rhonda D

2015-02-01

Current approved nucleoside therapies for genital herpes simplex virus (HSV) infections are effective but improved therapies are needed for treatment of both acute and recurrent diseases. The effects of N-methanocarbathymidine were evaluated and compared to acyclovir using guinea pig models of acute and recurrent infection. For acute disease following intravaginal inoculation of 10(6 )pfu HSV-2 (MS strain), animals were treated intraperitoneally beginning 24 h post-infection, and the effects on disease severity, vaginal virus replication, subsequent recurrences, and latent virus loads were evaluated. For evaluation of recurrent infection, animals were treated for 21 days beginning 14 days after infection and disease recurrence and recurrent shedding were evaluated. Treatment of the acute disease with N-methanocarbathymidine significantly reduced the severity of acute disease and decreased acute vaginal virus shedding more effectively than acyclovir. Significantly, none of the animals developed visible disease in the high-dose N-methanocarbathymidine group and this was the only group in which the number of days with recurrent virus shedding was reduced. Treatment of recurrent disease was equivalent to acyclovir when acyclovir was continuously supplied in the drinking water. N-methanocarbathymidine was effective as therapy for acute and recurrent genital HSV-2 disease in the guinea pig models. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Axial-Current Matrix Elements in Light Nuclei from Lattice QCD

Energy Technology Data Exchange (ETDEWEB)

Savage, Martin [Univ. of Washington, Seattle, WA (United States); Shanahan, Phiala E. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Tiburzi, Brian C. [Univ. of Maryland, College Park, MD (United States); Wagman, Michael L. [Univ. of Washington, Seattle, WA (United States); Winter, Frank T. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Beane, Silas [Univ. of New Hampshire, Durham, NH (United States); Chang, Emmanuel [Univ. of Washington, Seattle, WA (United States); Davoudi, Zohreh; Detmold, William [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Orginos, Konstantinos [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); College of William and Mary, Williamsburg, VA (United States)

2016-12-01

I present results from the first lattice QCD calculations of axial-current matrix elements in light nuclei, performed by the NPLQCD collaboration. Precision calculations of these matrix elements, and the subsequent extraction of multi-nucleon axial-current operators, are essential in refining theoretical predictions of the proton-proton fusion cross section, neutrino-nucleus cross sections and $\\beta\\beta$-decay rates of nuclei. In addition, they are expected to shed light on the phenomenological quenching of $g_A$ that is required in nuclear many-body calculations.

Parallel Beam Dynamics Simulation Tools for Future Light Source Linac Modeling

International Nuclear Information System (INIS)

Qiang, Ji; Pogorelov, Ilya v.; Ryne, Robert D.

2007-01-01

Large-scale modeling on parallel computers is playing an increasingly important role in the design of future light sources. Such modeling provides a means to accurately and efficiently explore issues such as limits to beam brightness, emittance preservation, the growth of instabilities, etc. Recently the IMPACT codes suite was enhanced to be applicable to future light source design. Simulations with IMPACT-Z were performed using up to one billion simulation particles for the main linac of a future light source to study the microbunching instability. Combined with the time domain code IMPACT-T, it is now possible to perform large-scale start-to-end linac simulations for future light sources, including the injector, main linac, chicanes, and transfer lines. In this paper we provide an overview of the IMPACT code suite, its key capabilities, and recent enhancements pertinent to accelerator modeling for future linac-based light sources

Quantifying shedding of synthetic fibers from textiles; a source of microplastics released into the environment.

Science.gov (United States)

Carney Almroth, Bethanie M; Åström, Linn; Roslund, Sofia; Petersson, Hanna; Johansson, Mats; Persson, Nils-Krister

2018-01-01

Microplastics in the environment are a subject of intense research as they pose a potential threat to marine organisms. Plastic fibers from textiles have been indicated as a major source of this type of contaminant, entering the oceans via wastewater and diverse non-point sources. Their presence is also documented in terrestrial samples. In this study, the amount of microfibers shedding from synthetic textiles was measured for three materials (acrylic, nylon, polyester), knit using different gauges and techniques. All textiles were found to shed, but polyester fleece fabrics shed the greatest amounts, averaging 7360 fibers/m -2 /L -1 in one wash, compared with polyester fabrics which shed 87 fibers/m -2 /L -1 . We found that loose textile constructions shed more, as did worn fabrics, and high twist yarns are to be preferred for shed reduction. Since fiber from clothing is a potentially important source of microplastics, we suggest that smarter textile construction, prewashing and vacuum exhaustion at production sites, and use of more efficient filters in household washing machines could help mitigate this problem.

Stochastic biomathematical models with applications to neuronal modeling

CERN Document Server

Batzel, Jerry; Ditlevsen, Susanne

2013-01-01

Stochastic biomathematical models are becoming increasingly important as new light is shed on the role of noise in living systems. In certain biological systems, stochastic effects may even enhance a signal, thus providing a biological motivation for the noise observed in living systems. Recent advances in stochastic analysis and increasing computing power facilitate the analysis of more biophysically realistic models, and this book provides researchers in computational neuroscience and stochastic systems with an overview of recent developments. Key concepts are developed in chapters written by experts in their respective fields. Topics include: one-dimensional homogeneous diffusions and their boundary behavior, large deviation theory and its application in stochastic neurobiological models, a review of mathematical methods for stochastic neuronal integrate-and-fire models, stochastic partial differential equation models in neurobiology, and stochastic modeling of spreading cortical depression.

Shedding Light on Shadow Education

Science.gov (United States)

Kobakhidze, Magda Nutsa

2015-01-01

This essay review examines four different movies that directly or indirectly refer to the theme of private tutoring or, as it is widely called, shadow education. The movies, directed in locations as diverse as India, Turkey, and Cambodia, are all made from a critical perspective. The directors demonstrate challenges in public education systems and…

Shedding light on the past

International Nuclear Information System (INIS)

Stampfl, A.P.J.; Friedman, E.S.; Wilkinson, T.J.; Alp, E.E.; Yener, K.A.

2001-01-01

The Amuq valley in southern Turkey is an important and interesting area in the Near East forming a space-time bridge for archaeologists and scientists to ancient and modern civilizations. The Lake of Antioch which evolved during the mid-late Holocene appears to have been located nearby some of the largest human settlements existing during this period. By documenting the conditions of the lake in time, using classical and modern approaches, the climate and geomorphology of the basin may be reconstructed. Synchrotron X-ray fluorescence measurements were performed on sections of a sedimentary core from the lake, representing an estimated 7500 yr of history. Analysis yielded the distribution of elemental masses spanning Ca to Mo as a function of depth from the surface. We find that the elemental concentrations measured follow a number of distinct patterns that may be related to local geomorphology, climate and human activities

[Shedding light on chaos theory].

Science.gov (United States)

Chou, Shieu-Ming

2004-06-01

Gleick (1987) said that only three twentieth century scientific theories would be important enough to continue be of use in the twenty-first century: The Theory of Relativity, Quantum Theory, and Chaos Theory. Chaos Theory has become a craze which is being used to forge a new scientific system. It has also been extensively applied in a variety of professions. The purpose of this article is to introduce chaos theory and its nursing applications. Chaos is a sign of regular order. This is to say that chaos theory emphasizes the intrinsic potential for regular order within disordered phenomena. It is to be hoped that this article will inspire more nursing scientists to apply this concept to clinical, research, or administrative fields in our profession.

Shedding light on energy transition

DEFF Research Database (Denmark)

Markovska, Natasa; Duić, Neven; Mathiesen, Brian Vad

2018-01-01

-carbon technologies in energy supply, buildings, transport, and industry, as well as address other key issues like demand response, co-benefits to other energy policies objectives, the role of declining costs for renewables and markets - all needed to facilitate energy sector transition. This editorial outlines......Ever since 2002, when the first Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES) was held in Dubrovnik, the SDEWES conferences series has been providing a forum for world-wide scientists and those interested in learning about the sustainability of development...... into account its economic, environmental and social pillars, as well as methods for assessing and measuring sustainability of development, regarding energy, transport, water, food production and environment systems and their many combinations. SDEWES has maintained high publishing standard as nearly 1100...

Shedding light to sleep studies

Science.gov (United States)

Dieffenderfer, James; Krystal, Andrew; Bozkurt, Alper

2017-08-01

This paper presents our efforts in the development of a small wireless, flexible bandage sized near-infrared spectroscopy (NIRS) system for sleep analysis. The current size of the system is 2.8 cm × 1.7 cm × 0.6 cm. It is capable of performing NIRS with 660nm, 940nm and 850nm wavelengths for up to 11 hours continuously. The device is placed on the forehead to measure from the prefrontal cortex and the raw data is continuously streamed over Bluetooth to a nearby data aggregator such as a smartphone for post processing and cloud connection. In this study, we performed traditional polysomnography simultaneously with NIRS to evaluate agreement with traditional measures of sleep and to provide labelled data for future work involving learning algorithms. Ultimately, we expect a machine learning algorithm to be able to generate characterization of sleep states comparable to traditional methods based on this biophotonics data. The system also includes an inertial measurement unit and the features that can be extracted from the presented system include sleep posture, heart rate, respiratory rate, relative change in oxy and deoxy hemoglobin concentrations and tissue oxygenation and cerebral arterial oxygen extracted from these. Preliminary proof of concept results are promising and demonstrate the capability to measure heart rate, respiratory rate and slow-wave-sleep stages. This system serves as a prototype to evaluate the potential of a small bandage-size continuous-wave NIRS device to be a useful means of studying sleep.

Shedding light on proteins, nucleic acids, cells, humans and fish

Science.gov (United States)

Setlow, Richard B.

2002-01-01

I was trained as a physicist in graduate school. Hence, when I decided to go into the field of biophysics, it was natural that I concentrated on the effects of light on relatively simple biological systems, such as proteins. The wavelengths absorbed by the amino acid subunits of proteins are in the ultraviolet (UV). The wavelengths that affect the biological activities, the action spectra, also are in the UV, but are not necessarily parallel to the absorption spectra. Understanding these differences led me to investigate the action spectra for affecting nucleic acids, and the effects of UV on viruses and cells. The latter studies led me to the discovery of the important molecular nature of the damages affecting DNA (cyclobutane pyrimidine dimers) and to the discovery of nucleotide excision repair. Individuals with the genetic disease xeroderma pigmentosum (XP) are extraordinarily sensitive to sunlight-induced skin cancer. The finding, by James Cleaver, that their skin cells were defective in DNA repair strongly suggested that DNA damage was a key step in carcinogenesis. Such information was important for estimating the wavelengths in sunlight responsible for human skin cancer and for predicting the effects of ozone depletion on the incidence of non-melanoma skin cancer. It took experiments with backcross hybrid fish to call attention to the probable role of the longer UV wavelengths not absorbed by DNA in the induction of melanoma. These reflections trace the biophysicist's path from molecules to melanoma.

Transcranial red and near infrared light transmission in a cadaveric model.

Directory of Open Access Journals (Sweden)

Jared R Jagdeo

Full Text Available BACKGROUND AND OBJECTIVE: Low level light therapy has garnered significant interest within the past decade. The exact molecular mechanisms of how red and near infrared light result in physiologic modulation are not fully understood. Heme moieties and copper within cells are red and near infrared light photoreceptors that induce the mitochondrial respiratory chain component cytochrome C oxidase, resulting in a cascade linked to cytoprotection and cellular metabolism. The copper centers in cytochrome C oxidase have a broad absorption range that peaks around 830 nm. Several in vitro and in vivo animal and human models exist that have demonstrated the benefits of red light and near infrared light for various conditions. Clinical applications for low level light therapy are varied. One study in particular demonstrated improved durable functional outcomes status post-stroke in patients treated with near infrared low level light therapy compared to sham treatment [1]. Despite previous data suggesting the beneficial effect in treating multiple conditions, including stroke, with low level light therapy, limited data exists that measures transmission in a human model. STUDY DESIGN/MATERIALS AND METHODS: To investigate this idea, we measured the transmission of near infrared light energy, using red light for purposes of comparison, through intact cadaver soft tissue, skull bones, and brain using a commercially available LED device at 830 nm and 633 nm. RESULTS: Our results demonstrate that near infrared measurably penetrates soft tissue, bone and brain parenchyma in the formalin preserved cadaveric model, in comparison to negligible red light transmission in the same conditions. CONCLUSION: These findings indicate that near infrared light can penetrate formalin fixed soft tissue, bone and brain and implicate that benefits observed in clinical studies are potentially related to direct action of near infrared light on neural tissue.

The Use of Canopy Models to Analyze Light Competition Among Plants

NARCIS (Netherlands)

Anten, N.P.R.; Bastiaans, L.

2016-01-01

Competition for light among plants is an important factor determining plant trait evolution and community dynamics. It may also strongly modulate crop production. Canopy models provide a useful means of analyzing light competition. This use however entails that these models take account of the

Prolonged Shedding of Human Parechovirus in Feces of Young Children after Symptomatic Infection

NARCIS (Netherlands)

Wildenbeest, Joanne G; Benschop, Kimberley S M; Bouma-de Jongh, Saskia; Wolthers, Katja C; Pajkrt, Dasja

2016-01-01

After symptomatic human parechovirus (HPeV) infection in infants, the duration of (mostly asymptomatic) shedding in feces was 2-24 weeks (median 58 days). HPeV cycle threshold value could neither differentiate between symptomatic disease and asymptomatic shedding nor between severe and mild disease

Reliability Constrained Priority Load Shedding for Aerospace Power System Automation

Science.gov (United States)

Momoh, James A.; Zhu, Jizhong; Kaddah, Sahar S.; Dolce, James L. (Technical Monitor)

2000-01-01

The need for improving load shedding on board the space station is one of the goals of aerospace power system automation. To accelerate the optimum load-shedding functions, several constraints must be involved. These constraints include congestion margin determined by weighted probability contingency, component/system reliability index, generation rescheduling. The impact of different faults and indices for computing reliability were defined before optimization. The optimum load schedule is done based on priority, value and location of loads. An optimization strategy capable of handling discrete decision making, such as Everett optimization, is proposed. We extended Everett method to handle expected congestion margin and reliability index as constraints. To make it effective for real time load dispatch process, a rule-based scheme is presented in the optimization method. It assists in selecting which feeder load to be shed, the location of the load, the value, priority of the load and cost benefit analysis of the load profile is included in the scheme. The scheme is tested using a benchmark NASA system consisting of generators, loads and network.

New Directions in Modeling the Lighting Systems

Directory of Open Access Journals (Sweden)

P. Fiala

2004-12-01

Full Text Available This paper presents information about new directions in the modelingof lighting systems, and an overview of methods for the modeling oflighting systems. The new R-FEM method is described, which is acombination of the Radiosity method and the Finite Elements Method. Thepaper contains modeling results and their verification by experimentalmeasurements and by the Matlab simulation for this R-FEM method.

New composite distributions for modeling industrial income and wealth per employee

Science.gov (United States)

Wiegand, Martin; Nadarajah, Saralees

2018-02-01

Forbes Magazine offers an annual list of the 2000 largest publicly traded companies, shedding light on four different measurements: Sales, profits, market value and assets held. Soriano-Hernández et al. (2017) modeled these wealth metrics using composite distributions made up of two parts. In this note, we introduce different composite distributions to more accurately describe the spread of these wealth metrics.

Velocity measurement by vortex shedding. Contribution to the mass-flow measurement

International Nuclear Information System (INIS)

Martinez Piquer, T.

1988-01-01

The phenomenon of vortex shedding has been known for centuries and has been the subject of scientific studies for about one hundred years. It is only in the ten last years that is has been applied to the measurement of fluids velocity. In 1878 F. Strouhal observed the vortex shedding phenomenon and shown that the shedding frequency of a wire vibrating in the wind was related to the wire diameter and the wind velocity. Rayleigh, who introduced the non-dimensional Strouhal number, von Karman and Rohsko, carried out extensive work or the subject which indicated that vortex shedding could form the basis for a new type of flowmeter. The thesis describes two parallel lines of investigation which study in depth the practical applications of vortex shedding. The first one deals with the measure of velocity and it presents the novelty of a bluff body with a cross-section which has not been used until this day. This body is a circular cylinder with a two-dimensional slit along the diameter and situated in crossdirection to the fluid's stream. It possesses excellent characteristics and it is the most stable as a vortex shedder, which gives it great advantage to the rest of the shapes used until now. The detection of the vortex has been performed by measuring the pressure changes generated by the vortex on two posts situated just beside the slit. To calculate the frequency of the vortex shedding, we obtain the difference of the mentioned signals, which are the same and 180 out of phase. Finding out the period of the autocorrelation function of this signal we can estimate the velocity of the fluid. A logical equipment based on a microprocessor has been designed for the calculation using a zero-crossing time algorithm implemented in assembler language. The second line of research refers to a new method of measure mass flow. The pressure signal generated by the vortex has an intensity which is proportional to the density and to the square of the velocity. Since we have already

Advanced modeling of reaction cross sections for light nuclei

International Nuclear Information System (INIS)

Resler, D.A.

1991-01-01

The shell model/R-matrix technique of calculating nuclear reaction cross sections for light projectiles incident on light nuclei is discussed, particularly in the application of the technique to thermonuclear reactions. Details are presented on the computational methods for the shell model which display how easily the calculations can be performed. Results of the shell model/R-matrix technique are discussed as are some of the problems encountered in picking an appropriate nucleon-nucleon interaction for the large model spaces which must be used for current problems. The status of our work on developing an effective nucleon-nucleon interaction for use in large-basis shell model calculations is presented. This new interaction is based on a combination of global constraints and microscopic nuclear data. 23 refs., 6 figs., 2 tabs

Fuzzy Load-Shedding Strategy Considering Photovoltaic Output Fluctuation Characteristics and Static Voltage Stability

Directory of Open Access Journals (Sweden)

Sheng Li

2018-03-01

Full Text Available Based on the equilibrium point equations of a classic three-node system integrated with a large-scale photovoltaic cell (PV power plant, the impact of PV output fluctuation on the saddle-node bifurcation (SNB was derived and analyzed. When PV runs in a unity power factor and the PV output active power Ppv is not too large (several hundred MW and below, the PV output fluctuation has little effect on the SNB point position and load margin index, so that the load margin index can be calculated online using the SNB point at Ppv = 0 pu. On the other hand, the local reactive power compensation in the load center can effectively raise the load bus voltage and make the voltage stability problem become more concealed; the traditional under-voltage load-shedding (UVLS strategy only carries out load shedding when the bus voltage amplitude is below the specified value and cannot effectively maintain the system static voltage stability in some occasions. In this paper, a fuzzy load-shedding strategy considering the impact of PV output fluctuations for the large-scale PV grid-connected system was designed, taking the load bus voltage amplitude and load margin index as fuzzy input variables, and the load-shedding command as a fuzzy output variable. Nine fuzzy IF-THEN rules were extracted for the fuzzy controller and the corresponding practical calculation method of load-shedding quantity was put forward. The simulation results of the classic three-node system and IEEE 14-bus system, both with a 100 MW PV power plant, verified the effectiveness of the fuzzy load-shedding controller whose input variable load margin index was calculated using the SNB point when the PV active power output was 0. The designed fuzzy load-shedding strategy can compensate for the defect—that the traditional UVLS strategy cannot effectively guarantee the system static voltage stability—and it can be widely used in power grids integrated with PV power plants whose scales are at a

Connecting the Kuramoto Model and the Chimera State

Science.gov (United States)

Kotwal, Tejas; Jiang, Xin; Abrams, Daniel M.

2017-12-01

Since its discovery in 2002, the chimera state has frequently been described as a counterintuitive, puzzling phenomenon. The Kuramoto model, in contrast, has become a celebrated paradigm useful for understanding a range of phenomena related to phase transitions, synchronization, and network effects. Here we show that the chimera state can be understood as emerging naturally through a symmetry-breaking bifurcation from the Kuramoto model's partially synchronized state. Our analysis sheds light on recent observations of chimera states in laser arrays, chemical oscillators, and mechanical pendula.

Factors associated with fecal-shedding of Salmonella spp by horses on US operations

Directory of Open Access Journals (Sweden)

Losinger W.C.

2002-01-01

Full Text Available In a cross-sectional national study that included 972 operations with > 3 horses on 1/1/98 in 28 states in the USA, 8,417 fecal specimens were collected from horses and cultured to test for the presence of Salmonella spp. Operations were characterized as Salmonella spp-positive if at least one fecal specimen tested positive for Salmonella spp. Percentages of Salmonella spp-positive operations were computed by management and other factors (collected from operation-level questionnaires that were hypothesized to be related to fecal shedding of Salmonella spp. A logistic-regression model was constructed to identify factors associated with horses? shedding Salmonella spp in feces on an operation. The odds of an operation being Salmonella spp positive increased as the number of resident horses increased. In addition, the following factors were found to be associated with increased odds of an operation being Salmonella spp positive: horses were used primarily for breeding; operation cleanliness was characterized as poor by the data collector; and new resident equids had been added to the operation without routine quarantine.

Housing a Raspberry Pi Connected AS-1 Seismometer in a Solar-Paneled Shed

Science.gov (United States)

Marton, F.; Tokman, T. L.; Echreshzadeh, M.; Palaric, K. D.; Filippone, N. V.; Sivo, J.

2016-12-01

Last year, students working on the SeismoSTEM project at Bergen Community College successfully manufactured and assembled an AS-1 seismometer1. However, issues students encountered were not knowing where to place the TC-1 and AS-1 seismometers, nor how to configure the instruments with a computer for monitoring and measuring earthquakes. Our solution was to purchase a Raspberry Pi 3 model B, which has four USB ports and a Wi-Fi adapter. We then installed the Raspbian operating system that can run jAmaSeis, which allows for the collection and analysis of seismic data. In terms of the shed that was constructed last summer2, we installed roof shingles, as well as a ventilation system to prevent overheating. The seismometers will then be placed on a concrete slab. In the future, we plan on applying a wood varnish around the exterior of the shed, as well as gravel around the shed for water drainage as well as to make it more visually appealing. Moreover, we plan on mounting a 170-W solar panel on the roof to charge a 12-V deep cycle marine battery, which will provide electricity to the system. References: 1Tokman, T.L. et al., What's shaking? Manufacturing & assembling an AS-1 educational seismometer for undergraduate stem research, Geological Society of America Abstracts with Programs. Vol. 47, No. 7, p.524, 2015. 2Palaric, K.D., et al., Constructing a solar-powered seismic station for educational seismometers, Geological Society of America Abstracts with Programs. Vol. 47, No. 7, p.524, 2015.

Strongyle egg shedding consistency in horses on farms using selective therapy in Denmark

DEFF Research Database (Denmark)

Nielsen, Martin Krarup; Haaning, Niels; Olsen, Susanne Nautrup

2006-01-01

Knowledge of horses that shed the same number of strongyle eggs over time can lead to the optimization of parasite control strategies. This study evaluated shedding of strongyle eggs in 424 horses on 10 farms whan a selective anthelmintic treatment regime was used over a 3-year period....

Men with disabilities - A cross sectional survey of health promotion, social inclusion and participation at community Men's Sheds.

Science.gov (United States)

Wilson, Nathan J; Cordier, Reinie; Parsons, Richard; Vaz, Sharmila; Buchanan, Angus

2016-01-01

The intersections between chronicity, disability and social inequality are well understood. Novel ways to counter the social determinants of health and disability are needed. Men's Sheds are a community space where men can participate in a range of shared activities and potentially experience a health and social benefits. This cross-sectional survey was conducted to inform future research by determining who attended Men's Sheds and the range of health, social, community, and educational activities undertaken there. This paper explores the membership of people with disabilities (PWD) at Men's Sheds and the factors that predict their membership. An online survey link was sent to all known Men's Sheds internationally in 2012. Data were analyzed using descriptive and inferential (univariate and multivariate) statistics. 32.2% of international sheds and 29% of Australian sheds specifically targeted the inclusion of PWD. 80% of these sheds have significantly more members with disabilities than sheds who do no target PWD. Factors associated with greater membership of PWD included the provision of transport, social outings and promoting occupational skills. PWD are being encouraged to join and are joining Men's Sheds. This is significant as the value of participation and inclusion toward better health and wellbeing is well known. Men's Sheds offer a community space where the social determinants of chronicity and disability can potentially be countered. Copyright © 2016 Elsevier Inc. All rights reserved.

A new parameterization for surface ocean light attenuation in Earth System Models: assessing the impact of light absorption by colored detrital material

OpenAIRE

G. E. Kim; M.-A. Pradal; A. Gnanadesikan

2015-01-01

Light limitation can affect the distribution of biota and nutrients in the ocean. Light absorption by colored detrital material (CDM) was included in a fully coupled Earth System Model using a new parameterization for shortwave attenuation. Two model runs were conducted, with and without light attenuation by CDM. In a global average sense, greater light limitation associated with CDM increased surface chlorophyll, biomass and nutrients together. These changes can be attribut...

Turnover of rod photoreceptor outer segments. II. Membrane addition and loss in relationship to light

International Nuclear Information System (INIS)

Besharse, J.C.; Hollyfield, J.G.; Rayborn, M.E.

1977-01-01

The rate of disk addition to rod outer segments (ROS) varies widely in Xenopus laevis tadpoles kept in cyclic light (12L:12D). When measured as radioactive band ( 3 H-band) displacement during the 2nd day after injection of [ 3 H]leucine, 75% of the daily increment of displacement occurred during the first 8 h of light. During the same interval, the number of open disks at the ROS base increased more than threefold. During the last 8 h of darkness, 3 H-band displacement was undetectable and the number of open disks was reduced. These observations suggest the possibility that disk addition may occur discontinuously. During the 3rd and 4th days after injection of [ 3 H]leucine, maximal displacement of the 3 H-band occurred later in the day than on the 2nd day, its movement no longer corresponding to the increase in open disks. This delay in 3 H-band displacement may reflect a time delay as a result of propagation of compressive stress in an elastic ROS system. Maximal disk loss from ROS as reflected in counts of phagosomes in the pigment epithelium occurred within 1 h of light exposure, and phagosome counts remained high for 4 h before declining to a low level in darkness. Modified lighting regimes affected the daily rhythms of shedding and disk addition differently, suggesting that control mechanisms for the two processes are not directly coupled. During 3 days in darkness, disk addition was reduced 50% compared to controls (12L:12D), whereas shedding was reduced by about 40%. Although reduced in level, shedding occurred as a free-running circadian rhythm

Highly efficient light management for perovskite solar cells.

Science.gov (United States)

Wang, Dong-Lin; Cui, Hui-Juan; Hou, Guo-Jiao; Zhu, Zhen-Gang; Yan, Qing-Bo; Su, Gang

2016-01-06

Organic-inorganic halide perovskite solar cells have enormous potential to impact the existing photovoltaic industry. As realizing a higher conversion efficiency of the solar cell is still the most crucial task, a great number of schemes were proposed to minimize the carrier loss by optimizing the electrical properties of the perovskite solar cells. Here, we focus on another significant aspect that is to minimize the light loss by optimizing the light management to gain a high efficiency for perovskite solar cells. In our scheme, the slotted and inverted prism structured SiO2 layers are adopted to trap more light into the solar cells, and a better transparent conducting oxide layer is employed to reduce the parasitic absorption. For such an implementation, the efficiency and the serviceable angle of the perovskite solar cell can be promoted impressively. This proposal would shed new light on developing the high-performance perovskite solar cells.

Supersymmetric models with light higgsinos

International Nuclear Information System (INIS)

Bruemmer, F.

2012-05-01

In the Minimal Supersymmetric Standard Model, the higgsinos can have masses around the electroweak scale, while the other supersymmetric particles have TeV-scale masses. This happens in models of gauge-mediated SUSY breaking with a high messenger scale, which are motivated from string theory. For particular choices of the messenger eld content, multi-TeV squark and gluino masses naturally lead to a much lower electroweak scale, somewhat similar to focus point supersymmetry. They also induce Higgs masses of 124-126 GeV, while making the discovery of supersymmetry at the LHC unlikely. The light higgsinos will be di cult to see at the LHC but may eventually be discovered at a linear collider.

Influence of On-farm pig Salmonella status on Salmonella Shedding at Slaughter.

Science.gov (United States)

Casanova-Higes, A; Andrés-Barranco, S; Mainar-Jaime, R C

2017-08-01

The risk of Salmonella shedding among pigs at slaughter with regard to their previous on-farm Salmonella status was assessed in a group of pigs from a farm from NE of Spain. A total of 202 pigs that had been serologically monitored monthly during the fattening period and from which mesenteric lymph nodes (MLN) and faecal (SFEC) samples were collected at slaughter for Salmonella isolation were included. A repeated-measures anova was used to assess the relationship between mean OD% values during the fattening period and sampling time and bacteriology on MLN and SFEC. Pigs were also grouped into four groups, that is pigs seronegative during the fattening period and Salmonella negative in MLN (group A; n = 69); pigs seronegative during the fattening period but Salmonella positive in MLN (B; n = 36); pigs seropositive at least once and Salmonella positive in MLN (C; n = 50); and pigs seropositive at least once but Salmonella negative in (D; n = 47). Pigs shedding at slaughter seroconverted much earlier and showed much higher mean OD% values than non-shedders pigs. The proportion of Salmonella shedders in groups A and D was high and similar (26.1% and 29.8%, respectively), but significantly lower than that for groups B and C. The odds of shedding Salmonella for groups B and C were 4.8 (95% CI = 1.5-15.5) and 20.9 (3.7-118) times higher, respectively, when compared to A. It was concluded that a large proportion of Salmonella seronegative pigs may shed Salmonella at slaughter, which would be likely associated to previous exposure with contaminated environments (i.e. transport and lairage). For pigs already infected at farm, the likelihood of shedding Salmonella was much higher and may depend on whether the bacterium has colonized the MLN or not. The odds of shedding Salmonella spp. were always much higher for pigs in which Salmonella was isolated from MLN. © 2016 Blackwell Verlag GmbH.

Rotavirus shedding following administration of RV3-BB human neonatal rotavirus vaccine.

Science.gov (United States)

Cowley, Daniel; Boniface, Karen; Bogdanovic-Sakran, Nada; Kirkwood, Carl D; Bines, Julie E

2017-08-03

The RV3-BB human neonatal rotavirus vaccine aims to provide protection from severe rotavirus disease from birth. A phase IIa safety and immunogenicity trial was undertaken in Dunedin, New Zealand between January 2012 and April 2014. Healthy, full-term (≥ 36 weeks gestation) babies, who were 0-5 d old were randomly assigned (1:1:1) to receive 3 doses of oral RV3-BB vaccine with the first dose given at 0-5 d after birth (neonatal schedule), or the first dose given at about 8 weeks after birth (infant schedule), or to receive placebo (placebo schedule). Vaccine take (serum immune response or stool shedding of vaccine virus after any dose) was detected after 3 doses of RV3-BB vaccine in >90% of participants when the first dose was administered in the neonatal and infant schedules. The aim of the current study was to characterize RV3-BB shedding and virus replication following administration of RV3-BB in a neonatal and infant vaccination schedule. Shedding was defined as detection of rotavirus by VP6 reverse transcription polymerase chain reaction (RT-PCR) in stool on days 3-7 after administration of RV3-BB. Shedding of rotavirus was highest following vaccination at 8 weeks of age in both neonatal and infant schedules (19/30 and 17/27, respectively). Rotavirus was detected in stool on days 3-7, after at least one dose of RV3-BB, in 70% (21/30) of neonate, 78% (21/27) of infant and 3% (1/32) placebo participants. In participants who shed RV3-BB, rotavirus was detectable in stool on day 1 following RV3-BB administration and remained positive until day 4-5 after administration. The distinct pattern of RV3-BB stool viral load demonstrated using a NSP3 quantitative qRT-PCR in participants who shed RV3-BB, suggests that detection of RV3-BB at day 3-7 was the result of replication rather than passage through the gastrointestinal tract.

Lightswitch 2002 : a model for electric lighting and blind usage in single offices

Energy Technology Data Exchange (ETDEWEB)

Reinhart, C.F. [National Research Council of Canada, Ottawa, ON (Canada). Inst. for Research in Construction

2003-04-03

This report presents the Lightswitch 2002 model which predicts the electric lighting energy demand in private offices with manually and automatically controlled lighting and blind systems. Some basic behaviour patterns that define occupant interaction with lighting and blind controls were also identified and incorporated into the simulation tool called Lightswitch Wizard. This study studied integrated lighting control systems in 20 offices with a SSW orientation. Integrated lighting control systems coordinate the control of automated electric lights and blind systems with conventional building energy management systems. The benefits include a gain in occupant comfort and energy performance. It was concluded that Lightswitch 2002 has an advantage over former models in that each manual switching decision has a probability function assigned to it and a random process decides whether a switching event takes place or not. It was shown that the annual electric lighting energy demand for a manually controlled lighting and blind system can vary between 10 and 39 kWh/m{sup 2} per year for different user types. The model has some technical limitations concerning intermediate switch-off, thermal consideration, privacy issues, seating orientation and the location of controls. It was suggested that the model should be integrated with a thermal and lighting simulation tool in order to assess overall energy performance of different lighting and blind control strategies. refs., tabs., figs.

Comparison of Coxiella burnetii shedding in milk of dairy bovine, caprine, and ovine herds.

Science.gov (United States)

Rodolakis, A; Berri, M; Héchard, C; Caudron, C; Souriau, A; Bodier, C C; Blanchard, B; Camuset, P; Devillechaise, P; Natorp, J C; Vadet, J P; Arricau-Bouvery, N

2007-12-01

The shedding of Coxiella burnetii in bovine, caprine, and ovine milk was measured using PCR, in 3 herds for each species, the bulk tank milk samples of which were positive at the time of their selection. Milk samples of 95 cows, 120 goats, and 90 ewes were sampled over 16 wk, as was the bulk tank milk. The shedding of C. burnetii in vaginal mucus and feces was checked at the beginning of the experiment and 2 mo later. The clinical signs in the selected herds as well as the duration and the shedding routes differed among the 3 species. The cows were asymptomatic and shed C. burnetii almost exclusively in milk. In one of the caprine herds, abortions due to C. burnetii were reported. The goats excreted the bacteria mainly in milk. In contrast, the ewes, which came from flocks with abortions due to Q fever (C. burnetii infection), shed the bacteria mostly in feces and in vaginal mucus. This could explain why human outbreaks of Q fever are more often related to ovine flocks than to bovine herds. These excretions did not seem more frequent when the samples were taken close to parturition. The samples were taken from 0 to 421 d after parturition in bovine herds and from 5 to 119 d and 11 to 238 d after parturition in the caprine and ovine herds, respectively. The shedding in milk was sometimes intermittent, and several animals shed the bacteria but were negative by ELISA: 80% of the ewes were seronegative, underscoring the lack of sensitivity of the ELISA tests available for veterinary diagnosis. The detection of antibodies in milk seems more sensitive than it is in serum.

Characterization, Modeling, and Optimization of Light-Emitting Diode Systems

DEFF Research Database (Denmark)

Thorseth, Anders

are simulated SPDs similar to traditional light sources, and with high light quality. As part of this work the techniques have been applied in practical illumination applications. The presented examples are historical artifacts and illumination of plants to increase photosynthesis....... comparing the chromaticity of the measured SPD with tted models, the deviation is found to be larger than the lower limit of human color perception. A method has been developed to optimize multicolored cluster LED systems with respect to light quality, using multi objective optimization. The results...

Regional impacts of iron-light colimitation in a global biogeochemical model

Science.gov (United States)

Galbraith, E. D.; Gnanadesikan, A.; Dunne, J. P.; Hiscock, M. R.

2010-03-01

Laboratory and field studies have revealed that iron has multiple roles in phytoplankton physiology, with particular importance for light-harvesting cellular machinery. However, although iron-limitation is explicitly included in numerous biogeochemical/ecosystem models, its implementation varies, and its effect on the efficiency of light harvesting is often ignored. Given the complexity of the ocean environment, it is difficult to predict the consequences of applying different iron limitation schemes. Here we explore the interaction of iron and nutrient cycles in an ocean general circulation model using a new, streamlined model of ocean biogeochemistry. Building on previously published parameterizations of photoadaptation and export production, the Biogeochemistry with Light Iron Nutrients and Gasses (BLING) model is constructed with only four explicit tracers but including macronutrient and micronutrient limitation, light limitation, and an implicit treatment of community structure. The structural simplicity of this computationally-inexpensive model allows us to clearly isolate the global effect that iron availability has on maximum light-saturated photosynthesis rates vs. the effect iron has on photosynthetic efficiency. We find that the effect on light-saturated photosynthesis rates is dominant, negating the importance of photosynthetic efficiency in most regions, especially the cold waters of the Southern Ocean. The primary exceptions to this occur in iron-rich regions of the Northern Hemisphere, where high light-saturated photosynthesis rates allow photosynthetic efficiency to play a more important role. In other words, the ability to efficiently harvest photons has little effect in regions where light-saturated growth rates are low. Additionally, we speculate that the phytoplankton cells dominating iron-limited regions tend to have relatively high photosynthetic efficiency, due to reduced packaging effects. If this speculation is correct, it would imply that

Regional impacts of iron-light colimitation in a global biogeochemical model

Directory of Open Access Journals (Sweden)

E. D. Galbraith

2010-03-01

Full Text Available Laboratory and field studies have revealed that iron has multiple roles in phytoplankton physiology, with particular importance for light-harvesting cellular machinery. However, although iron-limitation is explicitly included in numerous biogeochemical/ecosystem models, its implementation varies, and its effect on the efficiency of light harvesting is often ignored. Given the complexity of the ocean environment, it is difficult to predict the consequences of applying different iron limitation schemes. Here we explore the interaction of iron and nutrient cycles in an ocean general circulation model using a new, streamlined model of ocean biogeochemistry. Building on previously published parameterizations of photoadaptation and export production, the Biogeochemistry with Light Iron Nutrients and Gasses (BLING model is constructed with only four explicit tracers but including macronutrient and micronutrient limitation, light limitation, and an implicit treatment of community structure. The structural simplicity of this computationally-inexpensive model allows us to clearly isolate the global effect that iron availability has on maximum light-saturated photosynthesis rates vs. the effect iron has on photosynthetic efficiency. We find that the effect on light-saturated photosynthesis rates is dominant, negating the importance of photosynthetic efficiency in most regions, especially the cold waters of the Southern Ocean. The primary exceptions to this occur in iron-rich regions of the Northern Hemisphere, where high light-saturated photosynthesis rates allow photosynthetic efficiency to play a more important role. In other words, the ability to efficiently harvest photons has little effect in regions where light-saturated growth rates are low. Additionally, we speculate that the phytoplankton cells dominating iron-limited regions tend to have relatively high photosynthetic efficiency, due to reduced packaging effects. If this speculation is correct

Neural net based determination of generator-shedding requirements in electric power systems

Energy Technology Data Exchange (ETDEWEB)

Djukanovic, M [Electrical Engineering Inst. ' Nikola Tesla' , Belgrade (Yugoslavia); Sobajic, D J; Pao, Y -H [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Electrical Engineering and Applied Physics Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Computer Engineering and Science AI WARE Inc., Cleveland, OH (United States)

1992-09-01

This paper presents an application of artificial neural networks (ANN) in support of a decision-making process by power system operators directed towards the fast stabilisation of multi-machine systems. The proposed approach considers generator shedding as the most effective discrete supplementary control for improving the dynamic performance of faulted power systems and preventing instabilities. The sensitivity of the transient energy function (TEF) with respect to changes in the amount of dropped generation is used during the training phase of ANNs to assess the critical amount of generator shedding required to prevent the loss of synchronism. The learning capabilities of neural nets are used to establish complex mappings between fault information and the amount of generation to be shed, suggesting it as the control signal to the power system operator. (author)

Kinetic modeling sheds light on the mode of action of recombinant factor VIIa on thrombin generation.

Science.gov (United States)

Mitrophanov, Alexander Y; Reifman, Jaques

2011-10-01

The therapeutic potential of a hemostatic agent can be assessed by investigating its effects on the quantitative parameters of thrombin generation. For recombinant activated factor VII (rFVIIa)--a promising hemostasis-inducing biologic--experimental studies addressing its effects on thrombin generation yielded disparate results. To elucidate the inherent ability of rFVIIa to modulate thrombin production, it is necessary to identify rFVIIa-induced effects that are compatible with the available biochemical knowledge about thrombin generation mechanisms. The existing body of knowledge about coagulation biochemistry can be rigorously represented by a computational model that incorporates the known reactions and parameter values constituting the biochemical network. We used a thoroughly validated numerical model to generate activated factor VII (FVIIa) titration curves in the cases of normal blood composition, hemophilia A and B blood, blood lacking factor VII, blood lacking tissue factor pathway inhibitor, and diluted blood. We utilized the generated curves to perform systematic fold-change analyses for five quantitative parameters characterizing thrombin accumulation. The largest fold changes induced by increasing FVIIa concentration were observed for clotting time, thrombin peak time, and maximum slope of the thrombin curve. By contrast, thrombin peak height was much less affected by FVIIa titrations, and the area under the thrombin curve stayed practically unchanged. Comparisons with experimental data demonstrated that the computationally derived patterns can be observed in vitro. rFVIIa modulates thrombin generation primarily by accelerating the process, without significantly affecting the total amount of generated thrombin. Copyright © 2011 Elsevier Ltd. All rights reserved.

On the experimental determination of the one-way speed of light

International Nuclear Information System (INIS)

Perez, Israel

2011-01-01

In this paper the question of the isotropy of the one-way speed of light is addressed from an experimental perspective. In particular, we analyse two experimental methods commonly used in its determination. The analysis is aimed at clarifying the view that the one-way speed of light cannot be determined by techniques in which physical entities close paths. The procedure employed here will provide epistemological tools so that physicists understand that a direct measurement of the speed not only of light but of any physical entity is by no means trivial. Our results shed light on the physics behind the experiments which may be of interest for both physicists with an elemental knowledge in special relativity and philosophers of science.

On the experimental determination of the one-way speed of light

Energy Technology Data Exchange (ETDEWEB)

Perez, Israel, E-mail: cooguion@yahoo.com, E-mail: iperez@cicese.mx [Department of Applied Physics, Optics Division, CICESE, Carretera Ensena da-Tijuana 3918, Zona Playitas, CP 22860, Ensenada, Baja California (Mexico)

2011-07-15

In this paper the question of the isotropy of the one-way speed of light is addressed from an experimental perspective. In particular, we analyse two experimental methods commonly used in its determination. The analysis is aimed at clarifying the view that the one-way speed of light cannot be determined by techniques in which physical entities close paths. The procedure employed here will provide epistemological tools so that physicists understand that a direct measurement of the speed not only of light but of any physical entity is by no means trivial. Our results shed light on the physics behind the experiments which may be of interest for both physicists with an elemental knowledge in special relativity and philosophers of science.

Early light curves for Type Ia supernova explosion models

Science.gov (United States)

Noebauer, U. M.; Kromer, M.; Taubenberger, S.; Baklanov, P.; Blinnikov, S.; Sorokina, E.; Hillebrandt, W.

2017-12-01

Upcoming high-cadence transient survey programmes will produce a wealth of observational data for Type Ia supernovae. These data sets will contain numerous events detected very early in their evolution, shortly after explosion. Here, we present synthetic light curves, calculated with the radiation hydrodynamical approach STELLA for a number of different explosion models, specifically focusing on these first few days after explosion. We show that overall the early light curve evolution is similar for most of the investigated models. Characteristic imprints are induced by radioactive material located close to the surface. However, these are very similar to the signatures expected from ejecta-CSM or ejecta-companion interaction. Apart from the pure deflagration explosion models, none of our synthetic light curves exhibit the commonly assumed power-law rise. We demonstrate that this can lead to substantial errors in the determination of the time of explosion. In summary, we illustrate with our calculations that even with very early data an identification of specific explosion scenarios is challenging, if only photometric observations are available.

Faecal shedding of antimicrobial-resistant Clostridium difficile strains by dogs.

Science.gov (United States)

Álvarez-Pérez, S; Blanco, J L; Peláez, T; Lanzarot, M P; Harmanus, C; Kuijper, E; García, M E

2015-03-01

To longitudinally assess the shedding of antimicrobial resistant Clostridium difficile strains by clinically healthy dogs raised at breeding facilities. 18 puppies from three different litters (#1, 2 and 3) were sampled weekly from parturition to day 20-55 postpartum. Faecal samples from the mothers of litters #2 and 3 were also available for analysis. Bacterial isolates were ribotyped, tested for in vitro antimicrobial susceptibility and further characterised. C. difficile was recovered from all sampled animals of litters #1 and 2, and a third of puppies from litter #3, but marked differences in C. difficile recovery were detected in different age groups (0-100%). Recovered PCR ribotypes included 056 (22 isolates), 010 (6 isolates), 078 and 213 (2 isolates each), and 009 and 020 (1 isolate each). Different ribotypes were shed by four individual animals. Regardless of their origin and ribotype, all isolates demonstrated full resistance to levofloxacin. Additionally, all but one isolate (belonging to ribotype 078) were resistant to ertapenem, and all ribotype 010 isolates displayed high-level resistance to clindamycin, clarithromycin and erythromycin. A single ribotype 078 isolate showed metronidazole heteroresistance. Healthy dogs can shed antimicrobial-resistant C. difficile strains. © 2014 British Small Animal Veterinary Association.

Large-Eddy Simulation of turbulent vortex shedding

International Nuclear Information System (INIS)

Archambeau, F.

1995-06-01

This thesis documents the development and application of a computational algorithm for Large-Eddy Simulation. Unusually, the method adopts a fully collocated variable storage arrangement and is applicable to complex, non-rectilinear geometries. A Reynolds-averaged Navier-Stokes algorithm has formed the starting point of the development, but has been modified substantially: the spatial approximation of convection is effected by an energy-conserving central-differencing scheme; a second-order time-marching Adams-Bashforth scheme has been introduced; the pressure field is determined by solving the pressure-Poisson equation; this equation is solved either by use of preconditioned Conjugate-Gradient methods or with the Generalised Minimum Residual method; two types of sub-grid scale models have been introduced and examined. The algorithm has been validated by reference to a hierarchy of unsteady flows of increasing complexity starting with unsteady lid-driven cavity flows and ending with 3-D turbulent vortex shedding behind a square prism. In the latter case, for which extensive experimental data are available, special emphasis has been put on examining the dependence of the results on mesh density, near-wall treatment and the nature of the sub-grid-scale model, one of which is an advanced dynamic model. The LES scheme is shown to return time-average and phase-averaged results which agree well with experimental data and which support the view that LES is a promising approach for unsteady flows dominated by large periodic structures. (author)

Large-Eddy Simulation of turbulent vortex shedding

Energy Technology Data Exchange (ETDEWEB)

Archambeau, F

1995-06-01

This thesis documents the development and application of a computational algorithm for Large-Eddy Simulation. Unusually, the method adopts a fully collocated variable storage arrangement and is applicable to complex, non-rectilinear geometries. A Reynolds-averaged Navier-Stokes algorithm has formed the starting point of the development, but has been modified substantially: the spatial approximation of convection is effected by an energy-conserving central-differencing scheme; a second-order time-marching Adams-Bashforth scheme has been introduced; the pressure field is determined by solving the pressure-Poisson equation; this equation is solved either by use of preconditioned Conjugate-Gradient methods or with the Generalised Minimum Residual method; two types of sub-grid scale models have been introduced and examined. The algorithm has been validated by reference to a hierarchy of unsteady flows of increasing complexity starting with unsteady lid-driven cavity flows and ending with 3-D turbulent vortex shedding behind a square prism. In the latter case, for which extensive experimental data are available, special emphasis has been put on examining the dependence of the results on mesh density, near-wall treatment and the nature of the sub-grid-scale model, one of which is an advanced dynamic model. The LES scheme is shown to return time-average and phase-averaged results which agree well with experimental data and which support the view that LES is a promising approach for unsteady flows dominated by large periodic structures. (author) 87 refs.

Proteomics approaches shed new light on hibernation physiology.

Science.gov (United States)

Grabek, Katharine R; Martin, Sandra L; Hindle, Allyson G

2015-08-01

The broad phylogenetic distribution and rapid phenotypic transitions of mammalian hibernators imply that hibernation is accomplished by differential expression of common genes. Traditional candidate gene approaches have thus far explained little of the molecular mechanisms underlying hibernation, likely due to (1) incomplete and imprecise sampling of a complex phenotype, and (2) the forming of hypotheses about which genes might be important based on studies of model organisms incapable of such dynamic physiology. Unbiased screening approaches, such as proteomics, offer an alternative means to discover the cellular underpinnings that permit successful hibernation and may reveal previously overlooked, important pathways. Here, we review the findings that have emerged from proteomics studies of hibernation. One striking feature is the stability of the proteome, especially across the extreme physiological shifts of torpor-arousal cycles during hibernation. This has led to subsequent investigations of the role of post-translational protein modifications in altering protein activity without energetically wasteful removal and rebuilding of protein pools. Another unexpected finding is the paucity of universal proteomic adjustments across organ systems in response to the extreme metabolic fluctuations despite the universality of their physiological challenges; rather each organ appears to respond in a unique, tissue-specific manner. Additional research is needed to extend and synthesize these results before it will be possible to address the whole body physiology of hibernation.

Modelling of a laser-pumped light source for endoscopic surgery

Science.gov (United States)

Nadeau, Valerie J.; Elson, Daniel S.; Hanna, George B.; Neil, Mark A. A.

2008-09-01

A white light source, based on illumination of a yellow phosphor with a fibre-coupled blue-violet diode laser, has been designed and built for use in endoscopic surgery. This narrow light probe can be integrated into a standard laparoscope or inserted into the patient separately via a needle. We present a Monte Carlo model of light scattering and phosphorescence within the phosphor/silicone matrix at the probe tip, and measurements of the colour, intensity, and uniformity of the illumination. Images obtained under illumination with this light source are also presented, demonstrating the improvement in illumination quality over existing endoscopic light sources. This new approach to endoscopic lighting has the advantages of compact design, improved ergonomics, and more uniform illumination in comparison with current technologies.

Toxoplasma gondii: A study of oocyst re-shedding in domestic cats.

Science.gov (United States)

Zulpo, Dauton Luiz; Sammi, Ana Sue; Dos Santos, Joeleni Rosa; Sasse, João Pedro; Martins, Thais Agostinho; Minutti, Ana Flávia; Cardim, Sérgio Tosi; de Barros, Luiz Daniel; Navarro, Italmar Teodorico; Garcia, João Luis

2018-01-15

The aim of the present study was to evaluate the re-shedding of T. gondii oocysts in cats fed tissue cysts of homologous and heterologous strains 12, 24 and 36 months after the first infection. Thirteen cats were used in the present study and were divided into four groups: G1 (n=2), G2 (n=3), G3 (n=5), and G4 (n=3). G1, G3 and G4 cats were infected with brain cysts of ME49 and G2 with TgDoveBr8, both genotype II strains of T. gondii. The G1 and G2 cats were re-infected after twelve months with brain cysts of VEG strain (genotype III), and G3 cats were re-infected with TgDoveBr1 (genotype II). The G3 cats were re-infected a third time after 24 months from the second infection, and the G4 cats were re-infected 36 months after the initial infection with cysts of the VEG strain. The cats' feces were evaluated using fecal flotation and genotyped with PCR-RFLP. The serological responses for IgM, IgA and IgG were determined by ELISA. All cats shed oocysts after the initial infection. Only one G1 cat shed oocysts when re-infected after twelve months with the VEG strain. No G2 cats excreted oocysts after the second infection with VEG. G3 cats, when re-infected after twelve months with the TgDoveBr1 strain, did not shed oocysts. However, when challenged after a third time with the VEG strain, three out of four cats shed oocysts. In the G4 group, when re-infected after thirty-six months with the VEG strain, two out of three cats shed oocysts. All oocyst samples were genotyped and characterized as the same genotype from the inoculum. Protection against oocyst re-excretion occurred in 90%, 25%, and 33.4% of cats after 12, 24, and 36 months from the initial infection, respectively. Therefore, the environmental contamination by oocysts from re-infected adult cats is only 30% lower than from kittens. In conclusion, the excretion of T. gondii oocysts was higher in experimentally re-infected cats throughout the years, especially when a heterologous strain was used. Copyright © 2017

GreenLight Model 960.

Science.gov (United States)

Fernandes, Richard; Carey, Conn; Hynes, James; Papkovsky, Dmitri

2013-01-01

The importance of food safety has resulted in a demand for a more rapid, high-throughput method for total viable count (TVC). The industry standard for TVC determination (ISO 4833:2003) is widely used but presents users with some drawbacks. The method is materials- and labor-intensive, requiring multiple agar plates per sample. More importantly, the method is slow, with 72 h typically required for a definitive result. Luxcel Biosciences has developed the GreenLight Model 960, a microtiter plate-based assay providing a rapid high-throughput method of aerobic bacterial load assessment through analysis of microbial oxygen consumption. Results are generated in 1-12 h, depending on microbial load. The mix and measure procedure allows rapid detection of microbial oxygen consumption and equates oxygen consumption to microbial load (CFU/g), providing a simple, sensitive means of assessing the microbial contamination levels in foods (1). As bacteria in the test sample grow and respire, they deplete O2, which is detected as an increase in the GreenLight probe signal above the baseline level (2). The time required to reach this increase in signal can be used to calculate the CFU/g of the original sample, based on a predetermined calibration. The higher the initial microbial load, the earlier this threshold is reached (1).

Syndecan-4 shedding impairs macrovascular angiogenesis in diabetes mellitus

Energy Technology Data Exchange (ETDEWEB)

Li, Ran; Xie, Jun; Wu, Han; Li, Guannan; Chen, Jianzhou; Chen, Qinhua; Wang, Lian; Xu, Biao, E-mail: xubiao@medmail.com.cn

2016-05-20

Purpose: Syndecan-4 (synd4) is a ubiquitous heparan sulfate proteoglycan cell surface receptor that modulates cell proliferation, migration, mechanotransduction, and endocytosis. The extracellular domain of synd4 sheds heavily in acute inflammation, but the shedding of synd4 in chronic inflammation, such as diabetes mellitus (DM), is still undefined. We investigated the alterations of synd4 endothelial expression in DM and the influence of impaired synd4 signaling on angiogenesis in human umbilical vein endothelial cells (HUVECs), diabetic rats, synd4 null mice, and db/db mice. Material and methods: HUVECs were incubated with advanced glycation end products (AGEs). Western blot analysis was used to determine synd4 protein expression and ELISA was used to detect soluble synd4 fragments. The concentration of synd4 in the aortic endothelia of diabetic rats was detected by immunohistochemical staining. Aortic ring assays were performed to study the process of angiogenesis in the diabetic rats and in synd4 null and db/db mice. Recombinant adenoviruses containing the synd4 gene or null were constructed to enhance synd4 aortic expression in db/db mice. Results: Western blot analysis showed decreased expression of the synd4 extracellular domain in HUVECs, and ELISA detected increased soluble fragments of synd4 in the media. Synd4 endothelial expression in the aortas of diabetic rats was decreased. Aortic ring assay indicated impaired angiogenesis in synd4 null and db/db mice, which was partially reversed by synd4 overexpression in db/db mice. Conclusion: Synd4 shedding from vascular endothelial cells played an important role in the diabetes-related impairment of angiogenesis. -- Highlights: •Synd4 shedding from endothelial cells is accelerated under the stimulation of AGEs. •Extracellular domain of synd4 is diminished in the endothelium of DM rats. •Aortic rings of synd4 null mice showed impaired angiogenesis. •Overexpression of synd4 partly rescues macrovascular

Kinetics of viral shedding provide insights into the epidemiology of viral hemorrhagic septicemia in Pacific herring

Science.gov (United States)

Hershberger, Paul K.; Gregg, Jacob L.; Winton, James R.; Grady, Courtney; Collins, Rachael

2010-01-01

Losses from infectious diseases are an important component of natural mortality among marine fish species, but factors controlling the ecology of these diseases and their potential responses to anthropogenic changes are poorly understood. We used viral hemorrhagic septicemia virus (VHSV) and a laboratory stock of Pacific herring Clupea pallasii to investigate the kinetics of viral shedding and its effect on disease transmission and host mortality. Outbreaks of acute disease, accompanied by mortality and viral shedding, were initiated after waterborne exposure of herring to concentrations of VHSV as low as 101 plaque-forming units (pfu) ml–1. Shed virus in flow-through tanks was first detected 4 to 5 d post-exposure, peaked after 6 to 10 d, and was no longer detected after 16 d. Shedding rates, calculated from density, flow and waterborne virus titer reached 1.8 to 5.0 × 108 pfu fish–1 d–1. Onset of viral shedding was dose-dependent and preceded initial mortality by 2 d. At 21 d, cumulative mortality in treatment groups ranged from 81 to 100% and was dependent not on challenge dose, but on the kinetics and level of viral shedding by infected fish in the tank. Possible consequences of the viral shedding and disease kinetics are discussed in the context of epizootic initiation and perpetuation among populations of wild Pacific herring.

Bovine coronavirus in naturally and experimentally exposed calves; viral shedding and the potential for transmission.

Science.gov (United States)

Oma, Veslemøy Sunniva; Tråvén, Madeleine; Alenius, Stefan; Myrmel, Mette; Stokstad, Maria

2016-06-13

Bovine coronavirus (BCoV) is a widely distributed pathogen, causing disease and economic losses in the cattle industry worldwide. Prevention of virus spread is impeded by a lack of basic knowledge concerning viral shedding and transmission potential in individual animals. The aims of the study were to investigate the duration and quantity of BCoV shedding in feces and nasal secretions related to clinical signs, the presence of virus in blood and tissues and to test the hypothesis that seropositive calves are not infectious to naïve in-contact calves three weeks after BCoV infection. A live animal experiment was conducted, with direct contact between animal groups for 24 h as challenge procedure. Four naïve calves were commingled with a group of six naturally infected calves and sequentially euthanized. Two naïve sentinel calves were commingled with the experimentally exposed group three weeks after exposure. Nasal swabs, feces, blood and tissue samples were analyzed for viral RNA by RT-qPCR, and virus isolation was performed on nasal swabs. Serum was analyzed for BCoV antibodies. The calves showed mild general signs, and the most prominent signs were from the respiratory system. The overall clinical score corresponded well with the shedding of viral RNA the first three weeks after challenge. General depression and cough were the signs that correlated best with shedding of BCoV RNA, while peak respiratory rate and peak rectal temperature appeared more than a week later than the peak shedding. Nasal shedding preceded fecal shedding, and the calves had detectable amounts of viral RNA intermittently in feces through day 35 and in nasal secretions through day 28, however virus isolation was unsuccessful from day six and day 18 from the two calves investigated. Viral RNA was not detected in blood, but was found in lymphatic tissue through day 42 after challenge. Although the calves were shedding BCoV RNA 21 days after infection the sentinel animals were not infected

Lysophosphatidic acid stimulates thrombomodulin lectin-like domain shedding in human endothelial cells

International Nuclear Information System (INIS)

Wu Hualin; Lin ChiIou; Huang Yuanli; Chen, Pin-Shern; Kuo, Cheng-Hsiang; Chen, Mei-Shing; Wu, G.C.-C.; Shi, G.-Y.; Yang, H.-Y.; Lee Hsinyu

2008-01-01

Thrombomodulin (TM) is an anticoagulant glycoprotein highly expressed on endothelial cell surfaces. Increased levels of soluble TM in circulation have been widely accepted as an indicator of endothelial damage or dysfunction. Previous studies indicated that various proinflammatory factors stimulate TM shedding in various cell types such as smooth muscle cells and epithelial cells. Lysophosphatidic acid (LPA) is a bioactive lipid mediator present in biological fluids during endothelial damage or injury. In the present study, we first observed that LPA triggered TM shedding in human umbilical vein endothelial cells (HUVECs). By Cyflow analysis, we showed that the LPA-induced accessibility of antibodies to the endothelial growth factor (EGF)-like domain of TM is independent of matrix metalloproteinases (MMPs), while LPA-induced TM lectin-like domain shedding is MMP-dependent. Furthermore, a stable cell line expressing TM without its lectin-like domain exhibited a higher cell proliferation rate than a stable cell line expressing full-length TM. These results imply that LPA induces TM lectin-like domain shedding, which might contribute to the exposure of its EGF-like domain for EGF receptor (EGFR) binding, thereby stimulating subsequent cell proliferation. Based on our findings, we propose a novel mechanism for the exposure of TM EGF-like domain, which possibly mediates LPA-induced EGFR transactivation

Multispectral simulation environment for modeling low-light-level sensor systems

Science.gov (United States)

Ientilucci, Emmett J.; Brown, Scott D.; Schott, John R.; Raqueno, Rolando V.

1998-11-01

Image intensifying cameras have been found to be extremely useful in low-light-level (LLL) scenarios including military night vision and civilian rescue operations. These sensors utilize the available visible region photons and an amplification process to produce high contrast imagery. It has been demonstrated that processing techniques can further enhance the quality of this imagery. For example, fusion with matching thermal IR imagery can improve image content when very little visible region contrast is available. To aid in the improvement of current algorithms and the development of new ones, a high fidelity simulation environment capable of producing radiometrically correct multi-band imagery for low- light-level conditions is desired. This paper describes a modeling environment attempting to meet these criteria by addressing the task as two individual components: (1) prediction of a low-light-level radiance field from an arbitrary scene, and (2) simulation of the output from a low- light-level sensor for a given radiance field. The radiance prediction engine utilized in this environment is the Digital Imaging and Remote Sensing Image Generation (DIRSIG) model which is a first principles based multi-spectral synthetic image generation model capable of producing an arbitrary number of bands in the 0.28 to 20 micrometer region. The DIRSIG model is utilized to produce high spatial and spectral resolution radiance field images. These images are then processed by a user configurable multi-stage low-light-level sensor model that applies the appropriate noise and modulation transfer function (MTF) at each stage in the image processing chain. This includes the ability to reproduce common intensifying sensor artifacts such as saturation and 'blooming.' Additionally, co-registered imagery in other spectral bands may be simultaneously generated for testing fusion and exploitation algorithms. This paper discusses specific aspects of the DIRSIG radiance prediction for low

Modelling light distributions of homogeneous versus discrete absorbers in light irradiated turbid media

NARCIS (Netherlands)

Verkruysse, W.; Lucassen, G. W.; de Boer, J. F.; Smithies, D. J.; Nelson, J. S.; van Gemert, M. J.

1997-01-01

Laser treatment of port wine stains has often been modelled assuming that blood is distributed homogeneously over the dermal volume, instead of enclosed within discrete vessels. The purpose of this paper is to analyse the consequences of this assumption. Due to strong light absorption by blood,

Shedding light on DOC release by benthic primary producers and its consumption by bioeroding sponges

NARCIS (Netherlands)

Müller, Benjamin

2015-01-01

The effect of light on dissolved organic carbon (DOC) release of benthic primary producers (BPPs) was investigated on the coral reefs of Curaçao. Incubation experiments revealed a positive relation between the DOC release of four Caribbean reef algae (Cladophora sp., Dictyota menstrualis, Lobophora

Flavobacterium psychrophilum, invasion into and shedding by rainbow trout Oncorhynchus mykiss

DEFF Research Database (Denmark)

Madetoja, J.; Nyman, P.; Wiklund, T.

2000-01-01

The infection route of Flavobacterium psychrophilum into rainbow trout Oncorhynchus mykiss was studied using bath and cohabitation challenges as well as oral challenge with live feed as a vector. Additionally, the number of bacterial cells shed by infected fish into the surrounding water...... is discussed as an important invasion route for F. psychrophilum into the fish. The shedding rate of F. psychrophiIlun by infected fish was associated with water temperature and the mortality of the infected fish. High numbers of F. psychrophilum cells were released into the water by dead rainbow trout during...

Coxiella burnetii shedding routes and antibody response after outbreaks of Q fever-induced abortion in dairy goat herds.

Science.gov (United States)

Rousset, Elodie; Berri, Mustapha; Durand, Benoit; Dufour, Philippe; Prigent, Myriam; Delcroix, Thibault; Touratier, Anne; Rodolakis, Annie

2009-01-01

Q fever is a zoonosis caused by Coxiella burnetii, a bacterium largely carried by ruminants and shed into milk, vaginal mucus, and feces. The main potential hazard to humans and animals is due to shedding of bacteria that can then persist in the environment and be aerosolized. The purpose of this study was to evaluate shedding after an outbreak of Q fever abortion in goat herds and to assess the relationship with the occurrence of abortions and antibody responses. Aborting and nonaborting goats were monitored by PCR for C. burnetii shedding 15 and 30 days after the abortion episodes. PCR analysis of all samples showed that 70% (n = 50) of the aborting and 53% (n = 70) of the nonaborting goats were positive. C. burnetii was shed into vaginal mucus, feces, and milk of 44%, 21%, and 38%, respectively, of goats that aborted and 27%, 20%, and 31%, respectively, of goats that delivered normally. Statistical comparison of these shedding results did not reveal any difference between these two groups. PCR results obtained for the vaginal and fecal routes were concordant in 81% of cases, whereas those for milk correlated with only 49% of cases with either vaginal or fecal shedding status. Serological analysis, using enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence assay (IFA), and complement fixation tests, showed that at least 24% of the seronegative goats shed bacteria. Positive vaginal and fecal shedding, unlike positive milk shedding, was observed more often in animals that were weakly positive or negative by ELISA or IFA. Two opposite shedding trends were thus apparent for the milk and vaginal-fecal routes. Moreover, this study showed that a nonnegligible proportion of seronegative animals that delivered normally could excrete C. burnetii.

A Bankruptcy Problem Approach to Load-shedding in Multiagent-based Microgrid Operation

OpenAIRE

Kim, Hak-Man; Kinoshita, Tetsuo; Lim, Yujin; Kim, Tai-Hoon

2010-01-01

A microgrid is composed of distributed power generation systems (DGs), distributed energy storage devices (DSs), and loads. To maintain a specific frequency in the islanded mode as an important requirement,  the control of DGs’ output and charge action of DSs are used in supply surplus conditions and load-shedding and discharge action of DSs are used in supply shortage conditions. Recently, multiagent systems for autonomous microgrid operation have been studied. Especially, load-shedding, whi...

Proteomic Analysis of Leptospira interrogans Shed in Urine of Chronically Infected Hosts▿

OpenAIRE

Monahan, Avril M.; Callanan, John J.; Nally, Jarlath E.

2008-01-01

Leptospirosis is a global zoonotic disease. The causative agent, pathogenic Leptospira species, survives in the renal tubules of chronically infected hosts, from where leptospires are shed via urine into the environment. Infection of new hosts can present as an array of acute and chronic disease processes reflecting variations in host-pathogen interactions. The present study was designed to reproduce the carrier phase of infection in Rattus norvegicus, thus facilitating shedding of leptospire...

Microscopic modeling of multi-lane highway traffic flow

Science.gov (United States)

Hodas, Nathan O.; Jagota, Anand

2003-12-01

We discuss a microscopic model for the study of multi-lane highway traffic flow dynamics. Each car experiences a force resulting from a combination of the desire of the driver to attain a certain velocity, aerodynamic drag, and change of the force due to car-car interactions. The model also includes multi-lane simulation capability and the ability to add and remove obstructions. We implement the model via a Java applet, which is used to simulate traffic jam formation, the effect of bottlenecks on traffic flow, and the existence of light, medium, and heavy traffic flow. The simulations also provide insight into how the properties of individual cars result in macroscopic behavior. Because the investigation of emergent characteristics is so common in physics, the study of traffic in this manner sheds new light on how the micro-to-macro transition works in general.

Co-occurrence of Trichomonas vaginalis and bacterial vaginosis and vaginal shedding of HIV-1 RNA.

Science.gov (United States)

Fastring, Danielle R; Amedee, Angela; Gatski, Megan; Clark, Rebecca A; Mena, Leandro A; Levison, Judy; Schmidt, Norine; Rice, Janet; Gustat, Jeanette; Kissinger, Patricia

2014-03-01

Trichomonas vaginalis (TV) and bacterial vaginosis (BV) are independently associated with increased risk of vaginal shedding in HIV-positive women. Because these 2 conditions commonly co-occur, this study was undertaken to examine the association between TV/BV co-occurrence and vaginal shedding of HIV-1 RNA. HIV-positive women attending outpatient HIV clinics in 3 urban US cities underwent a clinical examination; were screened for TV, BV, Neisseria gonorrhoeae, Chlamydia trachomatis, and vulvovaginal candidiasis; and completed a behavioral survey. Women shedding HIV-1 RNA vaginally (≥50 copies/mL) were compared with women who had an undetectable (women who were TV positive and BV positive or had co-occurrence of TV/BV had higher odds of shedding vaginally when compared with women who did not have these conditions. In this sample of 373 HIV-positive women, 43.1% (n = 161) had co-occurrence of TV/BV and 33.2% (n = 124) were shedding HIV-1 RNA vaginally. The odds of shedding HIV vaginally in the presence of TV alone or BV alone and when TV/BV co-occurred were 4.07 (95% confidence interval [CI], 1.78-9.37), 5.65 (95% CI, 2.64-12.01), and 18.63 (95% CI, 6.71-51.72), respectively, when compared with women with no diagnosis of TV or BV, and after adjusting for age, antiretroviral therapy status, and plasma viral load. T. vaginalis and BV were independently and synergistically related to vaginal shedding of HIV-1 RNA. Screening and prompt treatment of these 2 conditions among HIV-positive women are important not only clinically but for HIV prevention, as well.

"A Simplified 'Benchmark” Stock-flow Consistent (SFC) Post-Keynesian Growth Model"

OpenAIRE

Claudio H. Dos Santos; Gennaro Zezza

2007-01-01

Despite being arguably one of the most active areas of research in heterodox macroeconomics, the study of the dynamic properties of stock-flow consistent (SFC) growth models of financially sophisticated economies is still in its early stages. This paper attempts to offer a contribution to this line of research by presenting a simplified Post-Keynesian SFC growth model with well-defined dynamic properties, and using it to shed light on the merits and limitations of the current heterodox SFC li...

Generalized Beer-Lambert model for near-infrared light propagation in thick biological tissues

Science.gov (United States)

Bhatt, Manish; Ayyalasomayajula, Kalyan R.; Yalavarthy, Phaneendra K.

2016-07-01

The attenuation of near-infrared (NIR) light intensity as it propagates in a turbid medium like biological tissue is described by modified the Beer-Lambert law (MBLL). The MBLL is generally used to quantify the changes in tissue chromophore concentrations for NIR spectroscopic data analysis. Even though MBLL is effective in terms of providing qualitative comparison, it suffers from its applicability across tissue types and tissue dimensions. In this work, we introduce Lambert-W function-based modeling for light propagation in biological tissues, which is a generalized version of the Beer-Lambert model. The proposed modeling provides parametrization of tissue properties, which includes two attenuation coefficients μ0 and η. We validated our model against the Monte Carlo simulation, which is the gold standard for modeling NIR light propagation in biological tissue. We included numerous human and animal tissues to validate the proposed empirical model, including an inhomogeneous adult human head model. The proposed model, which has a closed form (analytical), is first of its kind in providing accurate modeling of NIR light propagation in biological tissues.

Inhibition of TGF-β Signaling in SHED Enhances Endothelial Differentiation.

Science.gov (United States)

Xu, J G; Gong, T; Wang, Y Y; Zou, T; Heng, B C; Yang, Y Q; Zhang, C F

2018-02-01

Low efficiency of deriving endothelial cells (ECs) from adult stem cells hampers their utilization in tissue engineering studies. The purpose of this study was to investigate whether suppression of transforming growth factor beta (TGF-β) signaling could enhance the differentiation efficiency of dental pulp-derived stem cells into ECs. We initially used vascular endothelial growth factor A (VEGF-A) to stimulate 2 dental pulp-derived stem cells (dental pulp stem cells and stem cells from human exfoliated deciduous teeth [SHED]) and compared their differentiation capacity into ECs. We further evaluated whether the vascular endothelial growth factor receptor I (VEGF-RI)-specific ligand placental growth factor-1 (PlGF-1) could mediate endothelial differentiation. Finally, we investigated whether the TGF-β signaling inhibitor SB-431542 could enhance the inductive effect of VEGF-A on endothelial differentiation, as well as the underlying mechanisms involved. ECs differentiated from dental pulp-derived stem cells exhibited the typical phenotypes of primary ECs, with SHED possessing a higher endothelial differentiation potential than dental pulp stem cells. VEGFR1-specific ligand-PLGF exerted a negligible effect on SHED-ECs differentiation. Compared with VEGF-A alone, the combination of VEGF-A and SB-431542 significantly enhanced the endothelial differentiation of SHED. The presence of SB-431542 inhibited the phosphorylation of Suppressor of Mothers Against Decapentaplegic 2/3 (SMAD2/3), allowing for VEGF-A-dependent phosphorylation and upregulation of VEGFR2. Our results indicate that the combination of VEGF-A and SB-431542 could enhance the differentiation of dental pulp-derived stem cells into endothelial cells, and this process is mediated through enhancement of VEGF-A-VEGFR2 signaling and concomitant inhibition of TGF-β-SMAD2/3 signaling.

Once Daily Valacyclovir for Reducing Viral Shedding in Subjects Newly Diagnosed with Genital Herpes

Directory of Open Access Journals (Sweden)

Mark G. Martens

2009-01-01

Results. 52 subjects had at least one PCR measurement in both treatment periods and comprised the primary efficacy population. Valacyclovir significantly reduced HSV-2 shedding during all days compared to placebo (mean 2.9% versus 13.5% of all days (P<.01, a 78% reduction. Valacyclovir significantly reduced subclinical HSV-2 shedding during all days compared to placebo (mean 2.4% versus 11.0% of all days (P<.01, a 78% reduction. However, 79% of subjects had no GH recurrences while receiving valacyclovir compared to 52% of subjects receiving placebo (P<.01. Conclusion. In this study, the frequency of total and subclinical HSV-2 shedding was greater than reported in earlier studies involving subjects with a history of symptomatic genital recurrences. Our study is the first to demonstrate a significant reduction in viral shedding with valacyclovir 1 g daily compared to placebo in a population of subjects newly diagnosed with HSV-2 infection.

A proteorhodopsin-based biohybrid light-powering pH sensor.

Science.gov (United States)

Rao, Siyuan; Guo, Zhibin; Liang, Dawei; Chen, Deliang; Wei, Yen; Xiang, Yan

2013-10-14

The biohybrid sensor is an emerging technique for multi-functional detection that utilizes the instinctive responses or interactions of biomolecules. We develop a biohybrid pH sensor by taking advantage of the pH-dependent photoelectric characteristics of proteorhodopsin (pR). The transient absorption kinetics study indicates that the photoelectric behavior of pR is attributed to the varying lifetime of the M intermediate at different environmental pH values. This pR-based biohybrid light-powering sensor with microfluidic design can achieve real-time pH detection with quick response and high sensitivity. The results of this work would shed light on pR and its potential applications.

Influence of excitation light rejection on forward model mismatch in optical tomography

International Nuclear Information System (INIS)

Hwang, K; Pan, T; Joshi, A; Rasmussen, J C; Bangerth, W; Sevick-Muraca, E M

2006-01-01

Fluorescence enhanced tomography for molecular imaging requires low background for detection and accurate image reconstruction. In this contribution, we show that excitation light leakage is responsible for elevated background and can be minimized with the use of gradient index (GRIN) lenses when using fibre optics to collect propagated fluorescence light from tissue or other biological media. We show that the model mismatch between frequency-domain photon migration (FDPM) measurements and the diffusion approximation prediction is decreased when GRIN lenses are placed prior to the interference filters to provide efficient excitation light rejection. Furthermore, model mismatch is correlated to the degree of excitation light leakage. This work demonstrates the importance of proper light filtering when designing fluorescence optical imaging and tomography

Shedding of a low pathogenic avian influenza virus in a common synanthropic mammal--the cottontail rabbit.

Directory of Open Access Journals (Sweden)

J Jeffrey Root

Full Text Available BACKGROUND: Cottontails (Sylvilagus spp. are common mammals throughout much of the U.S. and are often found in peridomestic settings, potentially interacting with livestock and poultry operations. If these animals are susceptible to avian influenza virus (AIV infections and shed the virus in sufficient quantities they may pose a risk for movement of avian influenza viruses between wildlife and domestic animals in certain situations. METHODOLOGY/PRINCIPAL FINDINGS: To assess the viral shedding potential of AIV in cottontails, we nasally inoculated fourteen cottontails with a low pathogenic AIV (H4N6. All inoculated cottontails shed relatively large quantities of viral RNA both nasally (≤ 10(6.94 PCR EID50 equivalents/mL and orally (≤ 10(5.09 PCR EID50 equivalents/mL. However, oral shedding tended to decline more quickly than did nasal shedding. No animals showed any obvious signs of disease throughout the study. Evidence of a serological response was found in all infected rabbits at 22 days post infection in convalescent sera. CONCLUSIONS/SIGNIFICANCE: To our knowledge, cottontails have not been previously assessed for AIV shedding. However, it was obvious that they shed AIV RNA extensively via the nasal and oral routes. This is significant, as cottontails are widely distributed throughout the U.S. and elsewhere. These mammals are often found in highly peridomestic situations, such as farms, parks, and suburban neighborhoods, often becoming habituated to human activities. Thus, if infected these mammals could easily transport AIVs short distances.

The shedding activity of ADAM17 is sequestered in lipid rafts

International Nuclear Information System (INIS)

Tellier, Edwige; Canault, Matthias; Rebsomen, Laure; Bonardo, Bernadette; Juhan-Vague, Irene; Nalbone, Gilles; Peiretti, Franck

2006-01-01

The tumor necrosis factor-alpha (TNF) converting enzyme (ADAM17) is a metalloprotease-disintegrin responsible for the cleavage of several biologically active transmembrane proteins. However, the substrate specificity of ADAM17 and the regulation of its shedding activity are still poorly understood. Here, we report that during its transport through the Golgi apparatus, ADAM17 is included in cholesterol-rich membrane microdomains (lipid rafts) where its prodomain is cleaved by furin. Consequently, ADAM17 shedding activity is sequestered in lipid rafts, which is confirmed by the fact that metalloproteinase inhibition increases the proportion of ADAM17 substrates (TNF and its receptors TNFR1 and TNFR2) in lipid rafts. Membrane cholesterol depletion increases the ADAM17-dependent shedding of these substrates demonstrating the importance of lipid rafts in the control of this process. Furthermore, ADAM17 substrates are present in different proportions in lipid rafts, suggesting that the entry of each of these substrates in these particular membrane microdomains is specifically regulated. Our data support the idea that one of the mechanisms regulating ADAM17 substrate cleavage involves protein partitioning in lipid rafts

Shedding of Japanese Encephalitis Virus in Oral Fluid of Infected Swine.

Science.gov (United States)

Lyons, Amy C; Huang, Yan-Jang S; Park, So Lee; Ayers, Victoria B; Hettenbach, Susan M; Higgs, Stephen; McVey, D Scott; Noronha, Leela; Hsu, Wei-Wen; Vanlandingham, Dana L

2018-05-09

Japanese encephalitis virus (JEV) is a zoonotic mosquito-borne flavivirus endemic in the Asia-Pacific region. Maintenance of JEV in nature involves enzootic transmission by competent Culex mosquitoes among susceptible avian and swine species. Historically, JEV has been regarded as one of the most important arthropod-borne viruses in Southeast Asia. Oronasal shedding of JEV from infected amplification hosts was not recognized until the recent discovery of vector-free transmission of JEV among domestic pigs. In this study, oral shedding of JEV was characterized in domestic pigs and miniature swine representing the feral phenotype. A rope-based sampling method followed by the detection of viral RNA using RT-qPCR allowed the collection and detection of JEV in oral fluid samples collected from intradermally challenged animals. The results suggest that the shedding of JEV in oral fluid can be readily detected by molecular diagnostic assays at the acute phase of infection. It also demonstrates the feasibility of this technique for the diagnosis and surveillance of JEV in swine species.

Shedding of the immunodominant P20 surface antigen of Eimeria bovis sporozoites.

OpenAIRE

Speer, C A; Whitmire, W M

1989-01-01

P20 is an immunodominant surface antigen of Eimeria bovis sporozoites. As parasites underwent merogony within cultured bovine monocytes and Madin-Darby bovine kidney (MDBK) cells, P20 appeared to be shed gradually by meronts and was absent in type 1 and 2 first-generation merozoites. Meronts of E. bovis appeared to shed P20 into the parasitophorous vacuole of bovine monocytes, whereas MDBK cells evidently released P20 into the culture medium or destroyed its antigenic determinant.

The Role of Shed PrPc in the Neuropathogenesis of HIV Infection.

Science.gov (United States)

Megra, Bezawit W; Eugenin, Eliseo A; Berman, Joan W

2017-07-01

HIV-1 enters the CNS soon after peripheral infection and causes chronic neuroinflammation and neuronal damage that leads to cognitive impairment in 40-70% of HIV-infected people. The nonpathogenic cellular isoform of the human prion protein (PrP c ) is an adhesion molecule constitutively expressed in the CNS. Previously, our laboratory showed that shed PrP c (sPrP c ) is increased in the cerebrospinal fluid of HIV-infected people with cognitive deficits as compared with infected people with no impairment. In this article, we demonstrate that CCL2 and TNF-α, inflammatory mediators that are elevated in the CNS of HIV-infected people, increase shedding of PrP c from human astrocytes by increasing the active form of the metalloprotease ADAM10. We show that the consequence of this shedding can be the production of inflammatory mediators, because treatment of astrocytes with rPrP c increased secretion of CCL2, CXCL-12, and IL-8. Supernatants from rPrP c -treated astrocytes containing factors produced in response to this treatment, but not rPrP c by itself, cause increased chemotaxis of both uninfected and HIV-infected human monocytes, suggesting a role for sPrP c in monocyte recruitment into the brain. Furthermore, we examined whether PrP c participates in glutamate uptake and found that rPrP c decreased uptake of this metabolite in astrocytes, which could lead to neurotoxicity and neuronal loss. Collectively, our data characterize mediators involved in PrP c shedding and the effect of this sPrP c on monocyte chemotaxis and glutamate uptake from astrocytes. We propose that shedding of PrP c could be a potential target for therapeutics to limit the cognitive impairment characteristic of neuroAIDS. Copyright © 2017 by The American Association of Immunologists, Inc.

Chiral soliton models for baryons

International Nuclear Information System (INIS)

Weigel, H.

2008-01-01

This concise research monograph introduces and reviews the concept of chiral soliton models for baryons. In these models, baryons emerge as (topological) defects of the chiral field. The many applications shed light on a number of baryon properties, ranging from static properties via nucleon resonances and deep inelastic scattering to even heavy ion collisions. As far as possible, the theoretical investigations are confronted with experiment. Conceived to bridge the gap between advanced graduate textbooks and the research literature, this volume also features a number of appendices to help nonspecialist readers to follow in more detail some of the calculations in the main text. (orig.)

The N domain of somatic angiotensin-converting enzyme negatively regulates ectodomain shedding and catalytic activity

OpenAIRE

Woodman, Zenda L.; Schwager, Sylva L. U.; Redelinghuys, Pierre; Carmona, Adriana K.; Ehlers, Mario R. W.; Sturrock, Edward D.

2005-01-01

sACE (somatic angiotensin-converting enzyme) consists of two homologous, N and C domains, whereas the testis isoenzyme [tACE (testis ACE)] consists of a single C domain. Both isoenzymes are shed from the cell surface by a sheddase activity, although sACE is shed much less efficiently than tACE. We hypothesize that the N domain of sACE plays a regulatory role, by occluding a recognition motif on the C domain required for ectodomain shedding and by influencing the catalytic efficiency. To test ...

Hepatocyte growth factor inhibitor-2 prevents shedding of matritpase

DEFF Research Database (Denmark)

Larsen, Brian R; Steffensen, Simon D; Nielsen, Nis V L

2013-01-01

Hepatocyte growth factor activator inhibitor-2 (HAI-2) is an inhibitor of many proteases in vitro, including the membrane-bound serine protease, matriptase. Studies of knock-out mice have shown that HAI-2 is essential for placental development only in mice expressing matriptase, suggesting that HAI......-2 is important for regulation of matriptase. Previous studies have shown that recombinant expression of matriptase was unsuccessful unless co-expressed with another HAI, HAI-1. In the present study we show that when human matriptase is recombinantly expressed alone in the canine cell line MDCK......, then human matriptase mRNA can be detected and the human matriptase ectodomain is shed to the media, suggesting that matriptase expressed alone is rapidly transported through the secretory pathway and shed. Whereas matriptase expressed together with HAI-1 or HAI-2 accumulates on the plasma membrane where...

Shedding Light on Fish Otolith Biomineralization Using a Bioenergetic Approach

Science.gov (United States)

Fablet, Ronan; Pecquerie, Laure; de Pontual, Hélène; Høie, Hans; Millner, Richard; Mosegaard, Henrik; Kooijman, Sebastiaan A. L. M.

2011-01-01

Otoliths are biocalcified bodies connected to the sensory system in the inner ears of fish. Their layered, biorhythm-following formation provides individual records of the age, the individual history and the natural environment of extinct and living fish species. Such data are critical for ecosystem and fisheries monitoring. They however often lack validation and the poor understanding of biomineralization mechanisms has led to striking examples of misinterpretations and subsequent erroneous conclusions in fish ecology and fisheries management. Here we develop and validate a numerical model of otolith biomineralization. Based on a general bioenergetic theory, it disentangles the complex interplay between metabolic and temperature effects on biomineralization. This model resolves controversial issues and explains poorly understood observations of otolith formation. It represents a unique simulation tool to improve otolith interpretation and applications, and, beyond, to address the effects of both climate change and ocean acidification on other biomineralizing organisms such as corals and bivalves. PMID:22110601

Shedding light on fish otolith biomineralization using a bioenergetic approach.

Directory of Open Access Journals (Sweden)

Ronan Fablet

Full Text Available Otoliths are biocalcified bodies connected to the sensory system in the inner ears of fish. Their layered, biorhythm-following formation provides individual records of the age, the individual history and the natural environment of extinct and living fish species. Such data are critical for ecosystem and fisheries monitoring. They however often lack validation and the poor understanding of biomineralization mechanisms has led to striking examples of misinterpretations and subsequent erroneous conclusions in fish ecology and fisheries management. Here we develop and validate a numerical model of otolith biomineralization. Based on a general bioenergetic theory, it disentangles the complex interplay between metabolic and temperature effects on biomineralization. This model resolves controversial issues and explains poorly understood observations of otolith formation. It represents a unique simulation tool to improve otolith interpretation and applications, and, beyond, to address the effects of both climate change and ocean acidification on other biomineralizing organisms such as corals and bivalves.

Computational Models for Analysis of Illicit Activities

DEFF Research Database (Denmark)

Nizamani, Sarwat

been explored in this thesis by considering them as epidemic-like processes. A mathematical model has been developed based on differential equations, which studies the dynamics of the issues from the very beginning until the issues cease. This study extends classical models of the spread of epidemics...... to describe the phenomenon of contagious public outrage, which eventually leads to the spread of violence following a disclosure of some unpopular political decisions and/or activity. The results shed a new light on terror activity and provide some hint on how to curb the spreading of violence within...

Evaluation of the shedding of Sarcocystis falcatula sporocysts in experimentally infected Virginia opossums (Didelphis virginiana).

Science.gov (United States)

Porter, R A; Ginn, P E; Dame, J B; Greiner, E C

2001-02-26

Five Virginia opossums (Didelphis virginiana) were fed muscles of brown-headed cowbirds (Molothrus ater) containing sarcocysts of Sarcocystis falcatula. Shedding of sporocysts was confirmed in all five opossums by fecal flotation. Counts were conducted daily for 2 weeks and then biweekly until the animals were euthanized and necropsied. The average prepatent period was 9.8 (7-16) days. The number of sporocysts shed varied greatly between the opossums with maximum mean shedding occurring at 71.6 (26-112) days post-infection (DPI). Average sporocyst production was 1480 sporocysts/gram of feces (SPG). Maximum output was 37,000 SPG. Average fecal yield in captivity was 17.5g of feces/day. Opossums shed 25,900 sporocysts/day (average) and a maximum of 647,500 sporocysts/day. All opossums shed sporocysts until time of euthanasia (46-200 DPI). Histologically, numerous sporocysts were present in the lamina propria at necropsy, primarily in the proximal half of the small intestine. Sporocysts were generally in clusters within the lamina propria of the luminal two-thirds of the villi. Sporocysts were found less frequently in the epithelium. No evidence of ongoing gametogony or other development was evident.

Model petri net of adaptive traffic lights and its collaboration with a special event

Directory of Open Access Journals (Sweden)

Tristono Tomi

2018-01-01

Full Text Available Traffic lights have an important role as the system control of vehicles flow on the urban network. Commonly, most countries still using fixed time strategy. Our research proposes the adaptive traffic lights model to response the traffic demand. It uses basic Petri net as a general modeling framework. Foractuating method of minimum and maximum green signal time interval, the green traffic lights have three-time extension units. Next, we collaborate on a case of the existence of railways that crosses on the southern arm of an intersection. We introduce both of collaboration model design of traffic lights and the railway's gate which always closes while a train passing. Verification and validation of the model are based on the simulation result of vehicles queue. The collaboration model design of traffic lights has excellent performance, and it can resolve the congestion problem better than conventional schedule.

Monte Carlo simulations shed light on Bathsheba's suspect breast.

Science.gov (United States)

Heijblom, Michelle; Meijer, Linda M; van Leeuwen, Ton G; Steenbergen, Wiendelt; Manohar, Srirang

2014-05-01

In 1654, Rembrandt van Rijn painted his famous painting Bathsheba at her Bath. Over the years, the depiction of Bathsheba's left breast and especially the presence of local discoloration, has generated debate on whether Rembrandt's Bathsheba suffered from breast cancer. Historical, medical and artistic arguments appeared to be not sufficient to prove if Bathsheba's model truly suffered from breast cancer. However, the bluish discoloration of the breast is an intriguing aspect from a biomedical optics point of view that might help us ending the old debate. By using Monte Carlo simulations in combination with the retinex theory of color vision, we showed that is highly unlikely that breast cancer results in a local bluish discoloration of the skin as is present on Bathsheba's breast. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Numerical Modelling of the Special Light Source with Novel R-FEM Method

Directory of Open Access Journals (Sweden)

Pavel Fiala

2008-01-01

Full Text Available This paper presents information about new directions in the modelling of lighting systems, and an overview of methods for the modelling of lighting systems. The novel R-FEM method is described, which is a combination of the Radiosity method and the Finite Elements Method (FEM. The paper contains modelling results and their verification by experimental measurements and by the Matlab simulation for this R-FEM method.

Shedding light on walking in the dark: the effects of reduced lighting on the gait of older adults with a higher-level gait disorder and controls

Directory of Open Access Journals (Sweden)

Gruendlinger Leor

2005-08-01

Full Text Available Abstract Objective To study the effects of reduced lighting on the gait of older adults with a high level gait disorder (HLGD and to compare their response to that of healthy elderly controls. Methods 22 patients with a HLGD and 20 age-matched healthy controls were studied under usual lighting conditions (1000 lumens and in near darkness (5 lumens. Gait speed and gait dynamics were measured under both conditions. Cognitive function, co-morbidities, depressive symptoms, and vision were also evaluated. Results Under usual lighting conditions, patients walked more slowly, with reduced swing times, and increased stride-to-stride variability, compared to controls. When walking under near darkness conditions, both groups slowed their gait. All other measures of gait were not affected by lighting in the controls. In contrast, patients further reduced their swing times and increased their stride-to-stride variability, both stride time variability and swing time variability. The unique response of the patients was not explained by vision, mental status, co-morbidities, or the values of walking under usual lighting conditions. Conclusion Walking with reduced lighting does not affect the gait of healthy elderly subjects, except for a reduction in speed. On the other hand, the gait of older adults with a HLGD becomes more variable and unsteady when they walk in near darkness, despite adapting a slow and cautious gait. Further work is needed to identify the causes of the maladaptive response among patients with a HLGD and the potential connection between this behavior and the increased fall risk observed in these patients.

New limb-darkening coefficients for modeling binary star light curves

Science.gov (United States)

Van Hamme, W.

1993-01-01

We present monochromatic, passband-specific, and bolometric limb-darkening coefficients for a linear as well as nonlinear logarithmic and square root limb-darkening laws. These coefficients, including the bolometric ones, are needed when modeling binary star light curves with the latest version of the Wilson-Devinney light curve progam. We base our calculations on the most recent ATLAS stellar atmosphere models for solar chemical composition stars with a wide range of effective temperatures and surface gravitites. We examine how well various limb-darkening approximations represent the variation of the emerging specific intensity across a stellar surface as computed according to the model. For binary star light curve modeling purposes, we propose the use of a logarithmic or a square root law. We design our tables in such a manner that the relative quality of either law with respect to another can be easily compared. Since the computation of bolometric limb-darkening coefficients first requires monochromatic coefficients, we also offer tables of these coefficients (at 1221 wavelength values between 9.09 nm and 160 micrometer) and tables of passband-specific coefficients for commonly used photometric filters.

Single-molecule fluorescence microscopy review: shedding new light on old problems.

Science.gov (United States)

Shashkova, Sviatlana; Leake, Mark C

2017-08-31

Fluorescence microscopy is an invaluable tool in the biosciences, a genuine workhorse technique offering exceptional contrast in conjunction with high specificity of labelling with relatively minimal perturbation to biological samples compared with many competing biophysical techniques. Improvements in detector and dye technologies coupled to advances in image analysis methods have fuelled recent development towards single-molecule fluorescence microscopy, which can utilize light microscopy tools to enable the faithful detection and analysis of single fluorescent molecules used as reporter tags in biological samples. For example, the discovery of GFP, initiating the so-called 'green revolution', has pushed experimental tools in the biosciences to a completely new level of functional imaging of living samples, culminating in single fluorescent protein molecule detection. Today, fluorescence microscopy is an indispensable tool in single-molecule investigations, providing a high signal-to-noise ratio for visualization while still retaining the key features in the physiological context of native biological systems. In this review, we discuss some of the recent discoveries in the life sciences which have been enabled using single-molecule fluorescence microscopy, paying particular attention to the so-called 'super-resolution' fluorescence microscopy techniques in live cells, which are at the cutting-edge of these methods. In particular, how these tools can reveal new insights into long-standing puzzles in biology: old problems, which have been impossible to tackle using other more traditional tools until the emergence of new single-molecule fluorescence microscopy techniques. © 2017 The Author(s).

Phenomenological study of extended seesaw model for light sterile neutrino

International Nuclear Information System (INIS)

Nath, Newton; Ghosh, Monojit; Goswami, Srubabati; Gupta, Shivani

2017-01-01

We study the zero textures of the Yukawa matrices in the minimal extended type-I seesaw (MES) model which can give rise to ∼ eV scale sterile neutrinos. In this model, three right handed neutrinos and one extra singlet S are added to generate a light sterile neutrino. The light neutrino mass matrix for the active neutrinos, m ν , depends on the Dirac neutrino mass matrix (M D ), Majorana neutrino mass matrix (M R ) and the mass matrix (M S ) coupling the right handed neutrinos and the singlet. The model predicts one of the light neutrino masses to vanish. We systematically investigate the zero textures in M D and observe that maximum five zeros in M D can lead to viable zero textures in m ν . For this study we consider four different forms for M R (one diagonal and three off diagonal) and two different forms of (M S ) containing one zero. Remarkably we obtain only two allowed forms of m ν (m eτ =0 and m ττ =0) having inverted hierarchical mass spectrum. We re-analyze the phenomenological implications of these two allowed textures of m ν in the light of recent neutrino oscillation data. In the context of the MES model, we also express the low energy mass matrix, the mass of the sterile neutrino and the active-sterile mixing in terms of the parameters of the allowed Yukawa matrices. The MES model leads to some extra correlations which disallow some of the Yukawa textures obtained earlier, even though they give allowed one-zero forms of m ν . We show that the allowed textures in our study can be realized in a simple way in a model based on MES mechanism with a discrete Abelian flavor symmetry group Z 8 ×Z 2 .

Laminar vortex shedding behind a cooled circular cylinder

Czech Academy of Sciences Publication Activity Database

Trávníček, Zdeněk; Wang, A. B.; Tu, W.Y.

2014-01-01

Roč. 55, č. 2 (2014), s. 1-12 ISSN 0723-4864 R&D Projects: GA ČR GA14-08888S Institutional support: RVO:61388998 Keywords : vortex shedding * cooled circular cylinder * thermal effect Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts Impact factor: 1.670, year: 2014 http://link.springer.com/journal/348/55/2/page/1

Discovery of a new strain of murine rotavirus that is consistently shed in large quantities after oral inoculation of adult mice

International Nuclear Information System (INIS)

McNeal, Monica M.; Belli, Janine; Basu, Mitali; Choi, Anthony H.-C.; Ward, Richard L.

2004-01-01

In 1990, we developed the adult mouse model for studies on active immunity against shedding of the EDIM strain of murine rotavirus. Low and inconsistent levels of EDIM shedding in some strains of adult mice, particularly those on C57BL/6 backgrounds, established the need for an alternative murine rotavirus strain for these studies. Fortuitously, such a rotavirus strain was obtained from mice housed within the conventional colony at Children's Hospital. This strain, named EMcN, was clearly distinguishable from EDIM based on electropherotype. Furthermore, sequence analyses of VP4 and VP7 genes of EMcN revealed non-identities in 5% of the amino acids of both proteins relative to EDIM but established EMcN as another G3P[16] strain of murine rotavirus. Subgroup analysis showed EMcN belonged to SG1 while EDIM was found to be non-SG1/SG2. Similarly, unlike EDIM, the EMcN strain was identified as serotype G3 based on neutralization by hyperimmune antisera developed against prototype human and simian G3 rotavirus strains. Although EDIM produced more days of diarrhea and was shed in greater quantities in neonatal BALB/c mice, EMcN was shed in much greater quantities in adult BALB/c mice. More importantly, in contrast to the EDIM strain, EMcN was shown to be consistently shed in large quantities in adult C57BL/6 mice and ko mice on this background. Therefore, it is recommended that the EMcN strain be used for future challenge studies with mice on this background

Re-evaluation of model-based light-scattering spectroscopy for tissue spectroscopy

Science.gov (United States)

Lau, Condon; Šćepanović, Obrad; Mirkovic, Jelena; McGee, Sasha; Yu, Chung-Chieh; Fulghum, Stephen; Wallace, Michael; Tunnell, James; Bechtel, Kate; Feld, Michael

2009-01-01

Model-based light scattering spectroscopy (LSS) seemed a promising technique for in-vivo diagnosis of dysplasia in multiple organs. In the studies, the residual spectrum, the difference between the observed and modeled diffuse reflectance spectra, was attributed to single elastic light scattering from epithelial nuclei, and diagnostic information due to nuclear changes was extracted from it. We show that this picture is incorrect. The actual single scattering signal arising from epithelial nuclei is much smaller than the previously computed residual spectrum, and does not have the wavelength dependence characteristic of Mie scattering. Rather, the residual spectrum largely arises from assuming a uniform hemoglobin distribution. In fact, hemoglobin is packaged in blood vessels, which alters the reflectance. When we include vessel packaging, which accounts for an inhomogeneous hemoglobin distribution, in the diffuse reflectance model, the reflectance is modeled more accurately, greatly reducing the amplitude of the residual spectrum. These findings are verified via numerical estimates based on light propagation and Mie theory, tissue phantom experiments, and analysis of published data measured from Barrett’s esophagus. In future studies, vessel packaging should be included in the model of diffuse reflectance and use of model-based LSS should be discontinued. PMID:19405760

Optimal Load Shedding and Generation Rescheduling for Overload Suppression in Large Power Systems.

Science.gov (United States)

Moon, Young-Hyun

Ever-increasing size, complexity and operation costs in modern power systems have stimulated the intensive study of an optimal Load Shedding and Generator Rescheduling (LSGR) strategy in the sense of a secure and economic system operation. The conventional approach to LSGR has been based on the application of LP (Linear Programming) with the use of an approximately linearized model, and the LP algorithm is currently considered to be the most powerful tool for solving the LSGR problem. However, all of the LP algorithms presented in the literature essentially lead to the following disadvantages: (i) piecewise linearization involved in the LP algorithms requires the introduction of a number of new inequalities and slack variables, which creates significant burden to the computing facilities, and (ii) objective functions are not formulated in terms of the state variables of the adopted models, resulting in considerable numerical inefficiency in the process of computing the optimal solution. A new approach is presented, based on the development of a new linearized model and on the application of QP (Quadratic Programming). The changes in line flows as a result of changes to bus injection power are taken into account in the proposed model by the introduction of sensitivity coefficients, which avoids the mentioned second disadvantages. A precise method to calculate these sensitivity coefficients is given. A comprehensive review of the theory of optimization is included, in which results of the development of QP algorithms for LSGR as based on Wolfe's method and Kuhn -Tucker theory are evaluated in detail. The validity of the proposed model and QP algorithms has been verified and tested on practical power systems, showing the significant reduction of both computation time and memory requirements as well as the expected lower generation costs of the optimal solution as compared with those obtained from computing the optimal solution with LP. Finally, it is noted that an

Faecal shedding of canine parvovirus after modified-live vaccination in healthy adult dogs.

Science.gov (United States)

Freisl, M; Speck, S; Truyen, U; Reese, S; Proksch, A-L; Hartmann, K

2017-01-01

Since little is known about the persistence and faecal shedding of canine parvovirus (CPV) in dogs after modified-live vaccination, diagnostic tests for CPV can be difficult to interpret in the post-vaccination period. The primary aim of this study was to determine the incidence, duration and extent of CPV vaccine virus shedding in adult dogs and to investigate related factors, including the presence of protective antibodies, increase in anti-CPV antibody titres and development of any gastrointestinal side-effects. A secondary objective was to assess prevalence of CPV field virus shedding in clinically healthy dogs due to subclinical infections. One hundred adult, healthy privately owned dogs were vaccinated with a commercial CPV-2 modified-live vaccine (MLV). Faeces were tested for the presence of CPV DNA on days 0 (prior to vaccination), 3, 7, 14, 21 and 28 by quantitative real-time PCR. Pre- and post-vaccination serum titres were determined by haemagglutination inhibition on days 0, 7 and 28. Transient excretion of CPV DNA was detected in 2.0% of dogs before vaccination. About one quarter of dogs (23.0%) shed CPV DNA during the post-vaccination period, but field and vaccine virus differentiation by VP2 gene sequencing was only successful in few samples. Faecal CPV excretion occurred despite protective serum antibody titres. Post-vaccination CPV shedding was not related to adequate antibody response after vaccination or to the occurrence of gastrointestinal side-effects. Despite individual differences, CPV DNA was detectable for up to 28 days after vaccination, although the faecal CPV DNA load in these clinically healthy dogs was very low. Copyright © 2016 Elsevier Ltd. All rights reserved.

Shedding and serological patterns of dairy cows following abortions associated with Coxiella burnetii DNA detection.

Science.gov (United States)

Guatteo, R; Joly, A; Beaudeau, F

2012-03-23

To describe both shedding and serological patterns following abortions detected as being associated with Coxiella burnetii (Cb), 24 cows experiencing an abortion due to Cb were followed over a one month period. Samples taken on the day of abortion (D0) were followed 3-fold by weekly samplings from day 14 (D14) to D28 after the abortion. Milk and vaginal mucus were collected at each weekly sampling and tested using real-time PCR while blood samples were collected 2-fold on D21 and D28 and tested using ELISA. We found a very short duration of C. burnetii shedding in vaginal mucus after abortion, highlighting the need to collect samples as rapidly as possible following an abortion to avoid false negative results. In contrast with previous results, concomitancy of vaginal and mucus shedding was frequent, especially for cows shedding a high bacterial load on DO leading to the hypothesis that the clinical onset of the infection influences the modalities of Cb shedding. Lastly, serological results indicating a lack of sensitivity to detect Cb shedder cows (especially for cows for which Ct values were high) suggest that ELISA is not a useful tool to diagnose abortions at the individual level. Copyright © 2011 Elsevier B.V. All rights reserved.

Computer Modeling of Daylight-Integrated Photocontrol of Electric Lighting Systems

Directory of Open Access Journals (Sweden)

Richard Mistrick

2015-05-01

Full Text Available This article presents a variety of different approaches to both model and assess the performance of daylight-integrated electric lighting control systems. In these systems, the output of a controlled lighting zone is based on a light sensor reading and a calibrated control algorithm. Computer simulations can consider the simulated illuminance data generated from both the electric lighting system and a daylight delivery system whose performance is addressed using typical meteorological year (TMY weather data. Photosensor signals and the operation of a control system’s dimming algorithms are also included. Methods and metrics for evaluating simulated performance for the purpose of making informed design decisions that lead to the best possible installed system performance are presented.

Retinal transcriptome sequencing sheds light on the adaptation to nocturnal and diurnal lifestyles in raptors.

Science.gov (United States)

Wu, Yonghua; Hadly, Elizabeth A; Teng, Wenjia; Hao, Yuyang; Liang, Wei; Liu, Yu; Wang, Haitao

2016-09-20

Owls (Strigiformes) represent a fascinating group of birds that are the ecological night-time counterparts to diurnal raptors (Accipitriformes). The nocturnality of owls, unusual within birds, has favored an exceptional visual system that is highly tuned for hunting at night, yet the molecular basis for this adaptation is lacking. Here, using a comparative evolutionary analysis of 120 vision genes obtained by retinal transcriptome sequencing, we found strong positive selection for low-light vision genes in owls, which contributes to their remarkable nocturnal vision. Not surprisingly, we detected gene loss of the violet/ultraviolet-sensitive opsin (SWS1) in all owls we studied, but two other color vision genes, the red-sensitive LWS and the blue-sensitive SWS2, were found to be under strong positive selection, which may be linked to the spectral tunings of these genes toward maximizing photon absorption in crepuscular conditions. We also detected the only other positively selected genes associated with motion detection in falcons and positively selected genes associated with bright-light vision and eye protection in other diurnal raptors (Accipitriformes). Our results suggest the adaptive evolution of vision genes reflect differentiated activity time and distinct hunting behaviors.

Spectra of heavy-light mesons in a relativistic model

Energy Technology Data Exchange (ETDEWEB)

Liu, Jing-Bin; Lue, Cai-Dian [Institute of High Energy Physics, Beijing (China)

2017-05-15

The spectra and wave functions of heavy-light mesons are calculated within a relativistic quark model which is based on a heavy-quark expansion of the instantaneous Bethe-Salpeter equation by applying the Foldy-Wouthuysen transformation. The kernel we choose is the standard combination of linear scalar and Coulombic vector. The effective Hamiltonian for heavy-light quark-antiquark system is calculated up to order 1/m{sub Q}{sup 2}. Our results are in good agreement with available experimental data except for the anomalous D{sub s0}{sup *}(2317) and D{sub s1}(2460) states. The newly observed heavy-light meson states can be accommodated successfully in the relativistic quark model with their assignments presented. The D{sub sJ}{sup *}(2860) can be interpreted as the vertical stroke 1{sup 3/2}D{sub 1} right angle and vertical stroke 1{sup 5/2}D{sub 3} right angle states being members of the 1D family with J{sup P} = 1{sup -} and 3{sup -}. (orig.)

Discovery Mondays - "Seeing the Universe in a different light"

CERN Multimedia

2005-01-01

The fibre-optic cables for the ALICE experiment. This evening should shed a little more light on CERN! Come and discover the role played by light in the research performed at CERN and how physicists make use of it to gain a better understanding of particles and the history of our Universe. Scientists will be inviting you to discover light in all its guises through a series of interactive demonstrations and fun activities open to the whole family. For example, you will be able to measure the speed of light with the help of a microwave oven and a bar of chocolate! You'll also find out how a camera or a telescope works. Children (aged between 8 and 10) will be able to make Newton's disc, an astonishing rainbow-coloured disc. The ALICE experiment will demonstrate to older participants how an electric signal produced following a collision between particles is first converted into a digital signal before being transmitted as a light signal to computers via a fibre-optic cable. Finally, you will be able to bec...

Discovery Mondays - "Seeing the Universe in a different light"

CERN Multimedia

2005-01-01

The fibre-optic cables for the ALICE experiment. This evening should shed a little more light on CERN! Come and discover the role played by light in the research performed at CERN or how physicists make use of it to gain a better understanding of particles and the history of our Universe. Legend The fibre-optic cables for the ALICE experiment. Scientists will therefore be inviting you to discover light in all its guises through a series of interactive demonstrations and fun activities open to the whole family. For example, you will be able to measure the speed of light with the help of a microwave oven and a bar of chocolate! You'll also find out how a camera or a telescope works. Children (aged between 8 and 10) will be able to make Newton's disc, an astonishing rainbow-coloured disc. The ALICE experiment will demonstrate to older participants how an electric signal produced following a collision between particles is first converted into a digital signal before being transmitted as a light signal to compu...

Entropic information of dynamical AdS/QCD holographic models

Energy Technology Data Exchange (ETDEWEB)

Bernardini, Alex E., E-mail: alexeb@ufscar.br [Departamento de Física, Universidade Federal de São Carlos, PO Box 676, 13565-905, São Carlos, SP (Brazil); Rocha, Roldão da, E-mail: roldao.rocha@ufabc.edu.br [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, UFABC, 09210-580, Santo André (Brazil)

2016-11-10

The Shannon based conditional entropy that underlies five-dimensional Einstein–Hilbert gravity coupled to a dilaton field is investigated in the context of dynamical holographic AdS/QCD models. Considering the UV and IR dominance limits of such AdS/QCD models, the conditional entropy is shown to shed some light onto the meson classification schemes, which corroborate with the existence of light-flavor mesons of lower spins in Nature. Our analysis is supported by a correspondence between statistical mechanics and information entropy which establishes the physical grounds to the Shannon information entropy, also in the context of statistical mechanics, and provides some specificities for accurately extending the entropic discussion to continuous modes of physical systems. From entropic informational grounds, the conditional entropy allows one to identify the lower experimental/phenomenological occurrence of higher spin mesons in Nature. Moreover, it introduces a quantitative theoretical apparatus for studying the instability of high spin light-flavor mesons.

A vortex-shedding flowmeter based on IPMCs

International Nuclear Information System (INIS)

Pasquale, Giovanna Di; Pollicino, Antonino; Graziani, Salvatore; Strazzeri, Salvatore

2016-01-01

Ionic polymer–metal composites (IPMCs) are electroactive polymers that can be used both as sensors and actuators. They have been demonstrated for many potential applications, in wet and underwater environments. Applications in fields such as biomimetics, robotics, and aerospace, just to mention a few, have been proposed. In this paper, the sensing nature of IPMCs is used to develop a flowmeter based on the vortex shedding phenomenon. The system is described, and a model is proposed and verified. A setup has been realized, and data have been acquired for many working conditions. The performance of the sensing system has been investigated by using acquired experimental data. Water flux velocities in the range [0.38, 2.83] m s −1 have been investigated. This working range is comparable with ranges claimed for established technologies. Results show the suitability of the proposed system to work as a flowmeter. The proposed transducer is suitable for envisaged post-silicon applications, where the use of IPMCs gives the opportunity to realize a new generating polymeric flowmeter. This has potential applications in fields where properties of IPMCs such as low cost, usability, and disposability are relevant. (paper)

Cation-Dependent Light-Induced Halide Demixing in Hybrid Organic-Inorganic Perovskites

OpenAIRE

Sutter-Fella, CM; Ngo, QP; Cefarin, N; Gardener, K; Tamura, N; Stan, CV; Drisdell, WS; Javey, A; Toma, FM; Sharp, ID

2018-01-01

© 2018 American Chemical Society. Mixed cation metal halide perovskites with increased power conversion efficiency, negligible hysteresis, and improved long term stability under illumination, moisture, and thermal stressing have emerged as promising compounds for photovoltaic and optoelectronic applications. Here, we shed light on photo-induced halide demixing using in-situ photoluminescence spectroscopy and in-situ synchrotron X-ray diffraction (XRD) to directly compare the evolution of comp...

Towards a 3D structural tomato model for calculating light interception

NARCIS (Netherlands)

Sarlikioti, V.; Marcelis, L.F.M.; Visser, de P.H.B.

2011-01-01

A number of physiological tomato models have been proposed the last decades, their main challenge being the correct simulation of fruit yield. For this, an accurate simulation of light interception, and thus photosynthesis, is of primary importance. Light interception is highly dependent of the

Design, characterization and modelling of high efficient solar powered lighting systems

DEFF Research Database (Denmark)

Svane, Frederik; Nymann, Peter; Poulsen, Peter Behrensdorff

2016-01-01

This paper discusses some of the major challenges in the development of L2L (Light-2-Light) products. It’s the lack of efficient converter electronics, modelling tools for dimensioning and furthermore, characterization facilities to support the successful development of the products. We report...

Strange star candidates revised within a quark model with chiral mass scaling

Institute of Scientific and Technical Information of China (English)

Ang Li; Guang-Xiong Peng; Ju-Fu Lu

2011-01-01

We calculate the properties of static strange stars using a quark model with chiral mass scaling. The results are characterized by a large maximum mass (～ 1.6 M⊙) and radius (～ 10 km). Together with a broad collection of modern neutron star models, we discuss some recent astrophysical observational data that could shed new light on the possible presence of strange quark matter in compact stars. We conclude that none of the present astrophysical observations can prove or confute the existence of strange stars.

Enhancing Localized Evaporation through Separated Light Absorbing Centers and Scattering Centers

Science.gov (United States)

Zhao, Dengwu; Duan, Haoze; Yu, Shengtao; Zhang, Yao; He, Jiaqing; Quan, Xiaojun; Tao, Peng; Shang, Wen; Wu, Jianbo; Song, Chengyi; Deng, Tao

2015-01-01

This report investigates the enhancement of localized evaporation via separated light absorbing particles (plasmonic absorbers) and scattering particles (polystyrene nanoparticles). Evaporation has been considered as one of the most important phase-change processes in modern industries. To improve the efficiency of evaporation, one of the most feasible methods is to localize heat at the top water layer rather than heating the bulk water. In this work, the mixture of purely light absorptive plasmonic nanostructures such as gold nanoparticles and purely scattering particles (polystyrene nanoparticles) are employed to confine the incident light at the top of the solution and convert light to heat. Different concentrations of both the light absorbing centers and the light scattering centers were evaluated and the evaporation performance can be largely enhanced with the balance between absorbing centers and scattering centers. The findings in this study not only provide a new way to improve evaporation efficiency in plasmonic particle-based solution, but also shed lights on the design of new solar-driven localized evaporation systems. PMID:26606898

Colour dependence of zodiacal light models

Science.gov (United States)

Giese, R. H.; Hanner, M. S.; Leinert, C.

1973-01-01

Colour models of the zodiacal light in the ecliptic have been calculated for both dielectric and metallic particles in the sub-micron and micron size range. Two colour ratios were computed, a blue ratio and a red ratio. The models with a size distribution proportional to s to the -2.5 power ds (where s is the particle radius) generally show a colour close to the solar colour and almost independent of elongation. Especially in the blue colour ratio there is generally no significant dependence on the lower cutoff size (0.1-1 micron). The main feature of absorbing particles is a reddening at small elongations. The models for size distributions proportional to s to the -4 power ds show larger departures from solar colour and more variation with model parameters. Colour measurements, including red and near infra-red, therefore are useful to distinguish between flat and steep size spectra and to verify the presence of slightly absorbing particles.

Th1 cytokine-induced syndecan-4 shedding by airway smooth muscle cells is dependent on mitogen-activated protein kinases.

Science.gov (United States)

Tan, Xiahui; Khalil, Najwa; Tesarik, Candice; Vanapalli, Karunasri; Yaputra, Viki; Alkhouri, Hatem; Oliver, Brian G G; Armour, Carol L; Hughes, J Margaret

2012-04-01

In asthma, airway smooth muscle (ASM) chemokine secretion can induce mast cell recruitment into the airways. The functions of the mast cell chemoattractant CXCL10, and other chemokines, are regulated by binding to heparan sulphates such as syndecan-4. This study is the first demonstration that airway smooth muscle cells (ASMC) from people with and without asthma express and shed syndecan-4 under basal conditions. Syndecan-4 shedding was enhanced by stimulation for 24 h with the Th1 cytokines interleukin-1β (IL-1β) or tumor necrosis factor-α (TNF-α), but not interferon-γ (IFNγ), nor the Th2 cytokines IL-4 and IL-13. ASMC stimulation with IL-1β, TNF-α, and IFNγ (cytomix) induced the highest level of syndecan-4 shedding. Nonasthmatic and asthmatic ASM cell-associated syndecan-4 protein expression was also increased by TNF-α or cytomix at 4-8 h, with the highest levels detected in cytomix-stimulated asthmatic cells. Cell-associated syndecan-4 levels were decreased by 24 h, whereas shedding remained elevated at 24 h, consistent with newly synthesized syndecan-4 being shed. Inhibition of ASMC matrix metalloproteinase-2 did not prevent syndecan-4 shedding, whereas inhibition of ERK MAPK activation reduced shedding from cytomix-stimulated ASMC. Although ERK inhibition had no effect on syndecan-4 mRNA levels stimulated by cytomix, it did cause an increase in cell-associated syndecan-4 levels, consistent with the shedding being inhibited. In conclusion, ASMC produce and shed syndecan-4 and although this is increased by the Th1 cytokines, the MAPK ERK only regulates shedding. ASMC syndecan-4 production during Th1 inflammatory conditions may regulate chemokine activity and mast cell recruitment to the ASM in asthma.

Hybrid diffusion and two-flux approximation for multilayered tissue light propagation modeling

Science.gov (United States)

Yudovsky, Dmitry; Durkin, Anthony J.

2011-07-01

Accurate and rapid estimation of fluence, reflectance, and absorbance in multilayered biological media has been essential in many biophotonics applications that aim to diagnose, cure, or model in vivo tissue. The radiative transfer equation (RTE) rigorously models light transfer in absorbing and scattering media. However, analytical solutions to the RTE are limited even in simple homogeneous or plane media. Monte Carlo simulation has been used extensively to solve the RTE. However, Monte Carlo simulation is computationally intensive and may not be practical for applications that demand real-time results. Instead, the diffusion approximation has been shown to provide accurate estimates of light transport in strongly scattering tissue. The diffusion approximation is a greatly simplified model and produces analytical solutions for the reflectance and absorbance in tissue. However, the diffusion approximation breaks down if tissue is strongly absorbing, which is common in the visible part of the spectrum or in applications that involve darkly pigmented skin and/or high local volumes of blood such as port-wine stain therapy or reconstructive flap monitoring. In these cases, a model of light transfer that can accommodate both strongly and weakly absorbing regimes is required. Here we present a model of light transfer through layered biological media that represents skin with two strongly scattering and one strongly absorbing layer.

Assessing the individual risk of fecal poliovirus shedding among vaccinated and non-vaccinated subjects following national health weeks in Mexico.

Directory of Open Access Journals (Sweden)

Leticia Ferreyra-Reyes

Full Text Available Mexico introduced inactivated polio vaccine (IPV into its routine immunization (RI schedule in 2007 but continued to give trivalent oral polio vaccine (tOPV twice a year during national health weeks (NHW through 2015.To evaluate individual variables associated with poliovirus (PV shedding among children with IPV-induced immunity after vaccination with tOPV and their household contacts.We recruited 72 children (both genders, ≤30 months, vaccinated with at least two doses of IPV and 144 household contacts (both genders, 2 per household, children and adults between 08/2010 and 09/2010 in Orizaba, Veracruz. Three NHW took place (one before and two after enrollment. We collected fecal samples monthly for 12 months, and tested 2500 samples for polioviruses types 1, 2 and 3 with three serotype-specific singleplex real-time RT-PCR (rRT-PCR assays. In order to increase the specificity for OPV virus, all positive and 112 negative samples were also processed with a two-step, OPV serotype-specific multiplex rRT-PCR.We estimated adjusted hazard ratios (HR and 95% CI using Cox proportional hazards regression for recurrent events models accounting for individual clustering to assess the association of individual variables with the shedding of any poliovirus for all participants and stratifying according to whether the participant had received tOPV in the month of sample collection.216 participants were included. Of the 2500 collected samples, using the singleplex rRT-PCR assay, PV was detected in 5.7% (n = 142; PV1 in 1.2% (n = 29, PV2 in 4.1% (n = 103, and PV3 in 1.9% (n = 48. Of the 256 samples processed by multiplex rRT-PCR, PV was detected in 106 (PV1 in 16.41% (n = 42, PV2 in 21.09% (n = 54, and PV3 in 23.05% (n = 59. Both using singleplex and multiplex assays, shedding of OPV among non-vaccinated children and subjects older than 5 years of age living in the same household was associated with shedding of PV2 by a household contact. All models were

Assessing the individual risk of fecal poliovirus shedding among vaccinated and non-vaccinated subjects following national health weeks in Mexico

Science.gov (United States)

Ferreyra-Reyes, Leticia; Cruz-Hervert, Luis Pablo; Troy, Stephanie B.; Huang, ChunHong; Sarnquist, Clea; Delgado-Sánchez, Guadalupe; Canizales-Quintero, Sergio; Holubar, Marisa; Ferreira-Guerrero, Elizabeth; Montero-Campos, Rogelio; Rodríguez-Álvarez, Mauricio; Mongua-Rodriguez, Norma; Maldonado, Yvonne

2017-01-01

Background Mexico introduced inactivated polio vaccine (IPV) into its routine immunization (RI) schedule in 2007 but continued to give trivalent oral polio vaccine (tOPV) twice a year during national health weeks (NHW) through 2015. Objectives To evaluate individual variables associated with poliovirus (PV) shedding among children with IPV-induced immunity after vaccination with tOPV and their household contacts. Materials and methods We recruited 72 children (both genders, ≤30 months, vaccinated with at least two doses of IPV) and 144 household contacts (both genders, 2 per household, children and adults) between 08/2010 and 09/2010 in Orizaba, Veracruz. Three NHW took place (one before and two after enrollment). We collected fecal samples monthly for 12 months, and tested 2500 samples for polioviruses types 1, 2 and 3 with three serotype-specific singleplex real-time RT-PCR (rRT-PCR) assays. In order to increase the specificity for OPV virus, all positive and 112 negative samples were also processed with a two-step, OPV serotype-specific multiplex rRT-PCR. Analysis We estimated adjusted hazard ratios (HR) and 95% CI using Cox proportional hazards regression for recurrent events models accounting for individual clustering to assess the association of individual variables with the shedding of any poliovirus for all participants and stratifying according to whether the participant had received tOPV in the month of sample collection. Results 216 participants were included. Of the 2500 collected samples, using the singleplex rRT-PCR assay, PV was detected in 5.7% (n = 142); PV1 in 1.2% (n = 29), PV2 in 4.1% (n = 103), and PV3 in 1.9% (n = 48). Of the 256 samples processed by multiplex rRT-PCR, PV was detected in 106 (PV1 in 16.41% (n = 42), PV2 in 21.09% (n = 54), and PV3 in 23.05% (n = 59). Both using singleplex and multiplex assays, shedding of OPV among non-vaccinated children and subjects older than 5 years of age living in the same household was associated with

Monte Carlo Simulations of Compressible Ising Models: Do We Understand Them?

Science.gov (United States)

Landau, D. P.; Dünweg, B.; Laradji, M.; Tavazza, F.; Adler, J.; Cannavaccioulo, L.; Zhu, X.

Extensive Monte Carlo simulations have begun to shed light on our understanding of phase transitions and universality classes for compressible Ising models. A comprehensive analysis of a Landau-Ginsburg-Wilson hamiltonian for systems with elastic degrees of freedom resulted in the prediction that there should be four distinct cases that would have different behavior, depending upon symmetries and thermodynamic constraints. We shall provide an account of the results of careful Monte Carlo simulations for a simple compressible Ising model that can be suitably modified so as to replicate all four cases.

A model that allows teachers to reflect on their ict approaches

DEFF Research Database (Denmark)

Kjeldsen, Lars Peter Bech; Kjærgaard, Hanne Wacher

2016-01-01

The increased global availability of technology and its entry onto the educational stage of Higher Education (HE) requires changes in the way we think of education and learning. This article will briefly describe and shed light on the new conditions for learning that are challenging our traditional...... pedagogical principles and present a model for pedagogical reflection that we call the Convergent Learning Space (CLS) consisting of the elements: Learning approaches; learning tools; learning spaces; availability; lifeworlds. The model reflects the choices and priorities teachers must make in relation...

Resuscitation from severe hemorrhagic shock after traumatic brain injury using saline, shed blood, or a blood substitute.

Science.gov (United States)

Gibson, Jeffrey B; Maxwell, Robert A; Schweitzer, John B; Fabian, Timothy C; Proctor, Kenneth G

2002-03-01

The original purpose of this study was to compare initial resuscitation of hemorrhagic hypotension after traumatic brain injury (TBI) with saline and shed blood. Based on those results, the protocol was modified and saline was compared to a blood substitute, diaspirin cross-linked hemoglobin (DCLHb). Two series of experiments were performed in anesthetized and mechanically ventilated (FiO2 = 0.4) pigs (35-45 kg). In Series 1, fluid percussion TBI (6-8 ATM) was followed by a 30% hemorrhage. At 120 min post-TBI, initial resuscitation consisted of either shed blood (n = 7) or a bolus of 3x shed blood volume as saline (n = 13). Saline supplements were then administered to all pigs to maintain a systolic arterial blood pressure (SAP) of >100 mmHg and a heart rate (HR) of 100 mmHg and a HR of CO2 reactivity was preserved with blood vs. saline (all P CO2 reactivity were improved, and ScvO2 was lower with DCLHb vs. saline (P effective than saline for resuscitation of TBI, whereas DCLHb was no more, and according to many variables, less effective than saline resuscitation. These experimental results are comparable to those in a recent multicenter trial using DCLHb for the treatment of severe traumatic shock. Further investigations in similar experimental models might provide some plausible explanations why DCLHb unexpectedly increased mortality in patients.

In Vitro Evaluation and Mechanism Analysis of the Fiber Shedding Property of Textile Pile Debridement Materials

Directory of Open Access Journals (Sweden)

Yijun Fu

2016-04-01

Full Text Available Fiber shedding is a critical problem in biomedical textile debridement materials, which leads to infection and impairs wound healing. In this work, single fiber pull-out test was proposed as an in vitro evaluation for the fiber shedding property of a textile pile debridement material. Samples with different structural design (pile densities, numbers of ground yarns and coating times were prepared and estimated under this testing method. Results show that single fiber pull-out test offers an appropriate in vitro evaluation for the fiber shedding property of textile pile debridement materials. Pull-out force for samples without back-coating exhibited a slight escalating trend with the supplement in pile density and number of ground yarn plies, while back-coating process significantly raised the single fiber pull-out force. For fiber shedding mechanism analysis, typical pull-out behavior and failure modes of the single fiber pull-out test were analyzed in detail. Three failure modes were found in this study, i.e., fiber slippage, coating point rupture and fiber breakage. In summary, to obtain samples with desirable fiber shedding property, fabric structural design, preparation process and raw materials selection should be taken into full consideration.

Universal Behavior in Excited Heavy-Light and Light-Light Mesons

OpenAIRE

Olsson, M. G.

1996-01-01

A common pattern of large orbital and radial excitations in heavy-light and light-light mesons is demonstrated. Within a general potential model the Regge slopes of the light degrees of freedom for these mesons are shown to be in the ratio of two. The possibility of ``tower'' degeneracy occurs only with pure scalar confinement.

[Light response characteristics of photosynthesis and model comparison of Distylium chinense in different flooding durations].

Science.gov (United States)

Liu, Ze-bin; Cheng, Rui-mei; Xiao, Wen-fa; Guo, Quan-shui; Wang, Na

2015-04-01

The light responses of photosynthesis of two-year-old Distytum chinense seedlings subjected to a simulated reservoir flooding environment in autumn and winter seasons were measured by using a Li-6400 XT portable photosynthesis system, and the light response curves were fitted and analyzed by three models of the rectangular hyperbola, non-rectangular hyperbola and modified rectangular hyperbola to investigate the applicability of different light response models for the D. chinense in different flooding durations and the adaption regulation of light response parameters to flooding stress. The results showed that the fitting effect of the non-rectangular hyperbola model for light response process of D. chinense under normal growth condition and under short-term flooding (15 days of flooding) was better than that of the other two models, while the fitting effect of the modified rectangular hyperbola model for light response process of D. chinense under longer-term flooding (30, 45 and 60 days of flooding) was better than that of the other two models. The modified rectangular hyperbola model gave the best fitted results of light compensation point (LCP) , maximum net photosynthetic rate (P(n max)) and light saturation point (LSP), and the non-rectangular hyperbola model gave the best fitted result of dark respiration rate (R(d)). The apparent quantum yield (Φ), P(n max) and LSP of D. chinense gradually decreased, and the LCP and R(d) of D. chinense gradually increased in early flooding (30 days), but D. chinense gradually produced adaptability for flooding as the flooding duration continued to increase, and various physiological indexes were gradually stabilized. Thus, this species has adaptability to some degree to the flooding environment.

Prospective cohort study showing persistent HSV-2 shedding in women with genital herpes 2 years after acquisition.

Science.gov (United States)

Ramchandani, Meena; Selke, Stacy; Magaret, Amalia; Barnum, Gail; Huang, Meei-Li Wu; Corey, Lawrence; Wald, Anna

2017-11-25

Herpes simplex virus type 2 (HSV-2) is a prevalent infection with great variability in clinical and virological manifestations among individuals. This prospective cohort study aims to evaluate the natural history of HSV-2 reactivation in the genital area in the same group of women over time. Eighteen immunocompetent HSV-2 seropositive women were evaluated for viral shedding for 70 consecutive days within a median of 8 months (range 1-24 months) of HSV-2 acquisition and again approximately 2.5 years later from the original study. Participants obtained daily swabs of genital secretions for HSV PCR and recorded genital symptoms. The viral shedding rate was 29% during the initial study and 19% in the follow-up study (32% reduction, P=0.019). Subclinical shedding rate also decreased from 24% to 13% (37% reduction, P=0.032), as did the rate of days with genital lesions from 22% to 15% (33% reduction, P=0.24). The mean copy number during viral shedding remained unchanged over time at 4.8 log 10 c/mL (SD=2.0 and 1.6 during each study, respectively, P=0.33). Women with high viral shedding rates in the past were likely to continue to have high shedding rates (r=0.63, P=0.005). Despite some reduction, high viral shedding rates persist in women with genital HSV-2 greater than 2 years after acquisition. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Avian bornavirus in free-ranging waterfowl: prevalence of antibodies and cloacal shedding of viral RNA.

Science.gov (United States)

Delnatte, Pauline; Nagy, Éva; Ojkic, Davor; Leishman, David; Crawshaw, Graham; Elias, Kyle; Smith, Dale A

2014-07-01

We surveyed free-ranging Canada Geese (Branta canadensis), Trumpeter Swans (Cygnus buccinator), Mute Swans (Cygnus olor), and Mallards (Anas platyrhynchos) to estimate the prevalence of antibodies to avian bornavirus (ABV) and of cloacal shedding of ABV RNA in southern Ontario, Canada. Blood samples and cloacal swabs were collected from 206 free-ranging Canada Geese, 135 Trumpeter Swans, 75 Mute Swans, and 208 Mallards at 10 main capture sites between October 2010 and May 2012. Sera were assessed for antibodies against ABV by enzyme-linked immunosorbent assay and swabs were evaluated for ABV RNA using real-time reverse-transcription PCR. Serum antibodies were detected in birds from all four species and at each sampling site. Thirteen percent of the geese caught on the Toronto Zoo site shed ABV RNA in feces compared with 0% in geese sampled at three other locations. The proportions of shedders among Mute Swans, Trumpeter Swans, and Mallards were 9%, 0%, and 0%, respectively. Birds that were shedding viral RNA were more likely to have antibodies against ABV and to have higher antibody levels than those that were not, although many birds with antibodies were not shedding. We confirmed that exposure to, or infection with, ABV is widespread in asymptomatic free-ranging waterfowl in Canada; however, the correlation between cloacal shedding, presence of antibodies, and presence of disease is not fully understood.

Effect of perforation on flow past a conic cylinder at Re = 100: vortex-shedding pattern and force history

Science.gov (United States)

Lin, L. M.; Zhong, X. F.; Wu, Y. X.

2017-09-01

The flow past a circular-section cylinder with a conic shroud perforated with four holes at the peak was simulated numerically at Re=100 , considering two factors, viz. the angle of attack and the diameter of the holes. The effects of the perforated conic shroud on the vortex shedding pattern in the near wake was mainly investigated, as well as the time history of the drag and lift forces. In the investigated parameter space, three flow regimes were generally identified, corresponding to weak, moderate, and strong disturbance effects. In regime I, the wake can mainly be described by alternately shedding Kármán or Kármán-like vortices. In regime II, the spanwise vortices are obviously disturbed along the span due to the appearance of additional vorticity components and their interactions with the spanwise vortices, but still shed in synchronization along the spanwise direction. In regime III, the typical Kármán vortices partially or totally disappear, and some new vortex shedding patterns appear, such as Ω -type, obliquely shedding, and crossed spanwise vortices with opposite sign. Corresponding to these complex vortex shedding patterns in the near wake, the fluid forces no longer oscillate regularly at a single vortex shedding frequency, but rather with a lower modulation frequency and multiple amplitudes. An overview of these flow regimes is presented.

A simple electromagnetic model for the light clock of special relativity

International Nuclear Information System (INIS)

Smith, Glenn S

2011-01-01

Thought experiments involving a light clock are common in introductory treatments of special relativity, because they provide a simple way of demonstrating the non-intuitive phenomenon of time dilation. The properties of the ray or pulse of light that is continuously reflected between the parallel mirrors of the clock are often stated vaguely and sometimes involve implicitly other relativistic effects, such as aberration. While this approach is adequate for an introduction, it should be supplemented by a more accurate analysis of the light clock once the formulae for the Lorentz transformation and the transformation of the electromagnetic field have been developed. A simple yet accurate electromagnetic model for the light clock is presented for this purpose. In this model, the ray of light in the qualitative treatment is replaced by a guided wave in a parallel-plate waveguide. Expressions for the electromagnetic field and energy density within the waveguide are determined in the inertial frame in which the clock is at rest and the laboratory frame in which the clock is moving with constant velocity. The analytical expressions and graphical results obtained clearly demonstrate the operation of the clock and time dilation, as well as other interesting relativistic effects.

Fly proof net shed for livestock: A novel concept of physical barrier for integrated management of Culicoides spp. (Diptera: Ceratopogonidae

Directory of Open Access Journals (Sweden)

B. W. Narladkar

2014-11-01

Full Text Available Aim: An age old and time tested technique of mosquito net requiring no energy, used by humans since prehistoric period was the inspiration behind this novel technique of fly proof net shed for livestock. With the aim to develop similar type of net shed for animals, which will protect them at night from biting of range of insects from Culicoides midges to mosquitoes, research was undertaken. Materials and Methods: Net shed with pitch roof (gable type was erected for use of livestock. The open inlet area was covered with 40 mesh size wire net. The roof at attic level was fitted with hurricane type of ventilator. Shed was used for animals at night hours only. vane anemometer was used for estimation of temperature and wind related parameters. Thermal humidity index (THI and air changes were calculated as per the standard formulas. Based on these parameters suitability of shed was judged. Results: It was observed that, due to netting of the shed population of Culicoides and other flies and incidences of their bites at night hours were considerably lowered. As a result, animals were found comfortable, and their body movements undertaken for wiping off these flies were significantly reduced from 196.50 to 22.16. All it accrued to increased milk yield to the tune of 18.97% in the net shed buffaloes as against control shed. Studies on suitability and comfort to animals were tested by estimating THI and air changes per hour in the net shed, which also revealed the estimates in comfortable regimen and ventilation, remained not much affected despite of netting. Other parameters studied for testing its more accuracy by taking other species of animals as kids, for them also, shed was found suitable through estimation of various physiological and behavioral parameters. Finally, the efficacy of shed was judged on the basis of cost effectiveness. Highly encouraging results on the above said parameters endorsed the effectiveness of the technique. Conclusion: A

Virtual Geographic Simulation of Light Distribution within Three-Dimensional Plant Canopy Models

Directory of Open Access Journals (Sweden)

Liyu Tang

2017-12-01

Full Text Available Virtual geographic environments (VGEs have been regarded as an important new means of simulating, analyzing, and understanding complex geological processes. Plants and light are major components of the geographic environment. Light is a critical factor that affects ecological systems. In this study, we focused on simulating light transmission and distribution within a three-dimensional plant canopy model. A progressive refinement radiosity algorithm was applied to simulate the transmission and distribution of solar light within a detailed, three-dimensional (3D loquat (Eriobotrya japonica Lindl. canopy model. The canopy was described in three dimensions, and each organ surface was represented by a set of triangular facets. The form factors in radiosity were calculated using a hemi-cube algorithm. We developed a module for simulating the instantaneous light distribution within a virtual canopy, which was integrated into ParaTree. We simulated the distribution of photosynthetically active radiation (PAR within a loquat canopy, and calculated the total PAR intercepted at the whole canopy scale, as well as the mean PAR interception per unit leaf area. The ParaTree-integrated radiosity model simulates the uncollided propagation of direct solar and diffuse sky light and the light-scattering effect of foliage. The PAR captured by the whole canopy based on the radiosity is approximately 9.4% greater than that obtained using ray tracing and TURTLE methods. The latter methods do not account for the scattering among leaves in the canopy in the study, and therefore, the difference might be due to the contribution of light scattering in the foliage. The simulation result is close to Myneni’s findings, in which the light scattering within a canopy is less than 10% of the incident PAR. Our method can be employed for visualizing and analyzing the spatial distribution of light within a canopy, and for estimating the PAR interception at the organ and canopy

Dynamics of Salmonella Shedding and Welfare of Hens in Free-Range Egg Production Systems

Science.gov (United States)

Gole, Vaibhav C.; Woodhouse, Rebecca; Caraguel, Charles; Moyle, Talia; Rault, Jean-Loup; Sexton, Margaret

2016-01-01

ABSTRACT The current study investigated the effect of environmental stressors (i.e., weather changes) on Salmonella shedding in free-range production systems and the correlations with behavioral and physiological measures (i.e., fecal glucocorticoid metabolites). This involved longitudinal and point-in-time surveys of Salmonella shedding and environmental contamination on four commercial free-range layer farms. The shedding of Salmonella was variable across free-range farms and in different seasons. There was no significant effect of season on the Salmonella prevalence during this investigation. In this study, the combined Salmonella most probable number (MPN) counts in environmental (including feces, egg belt, dust, nest box, and ramp) samples were highest in samples collected during the summer season (4th sampling, performed in February). The predominant serovars isolated during this study were Salmonella enterica serovar Mbandaka and Salmonella enterica serovar Typhimurium phage types 135 and 135a. These two phage types were involved in several egg product-related Salmonella outbreaks in humans. Multilocus variable-number tandem-repeat analysis (MLVA) results indicated that MLVA types detected from human food poisoning cases exhibited MLVA patterns similar to the strains isolated during this study. All Salmonella isolates (n = 209) were tested for 15 different genes involved in adhesion, invasion, and survival of Salmonella spp. We also observed variations for sopA, ironA, and misL. There were no positive correlations between fecal corticosterone metabolite (FCM) and Salmonella prevalence and/or shedding in feces. Also, there were no positive correlations between Salmonella prevalence and Salmonella count (log MPN) and any of the other welfare parameters. IMPORTANCE In this study, the welfare of laying hens and Salmonella shedding were compared over a prolonged period of time in field conditions. This study investigated the long-term shedding of Salmonella

Dynamics of Salmonella Shedding and Welfare of Hens in Free-Range Egg Production Systems.

Science.gov (United States)

Gole, Vaibhav C; Woodhouse, Rebecca; Caraguel, Charles; Moyle, Talia; Rault, Jean-Loup; Sexton, Margaret; Chousalkar, Kapil

2017-03-01

The current study investigated the effect of environmental stressors (i.e., weather changes) on Salmonella shedding in free-range production systems and the correlations with behavioral and physiological measures (i.e., fecal glucocorticoid metabolites). This involved longitudinal and point-in-time surveys of Salmonella shedding and environmental contamination on four commercial free-range layer farms. The shedding of Salmonella was variable across free-range farms and in different seasons. There was no significant effect of season on the Salmonella prevalence during this investigation. In this study, the combined Salmonella most probable number (MPN) counts in environmental (including feces, egg belt, dust, nest box, and ramp) samples were highest in samples collected during the summer season (4th sampling, performed in February). The predominant serovars isolated during this study were Salmonella enterica serovar Mbandaka and Salmonella enterica serovar Typhimurium phage types 135 and 135a. These two phage types were involved in several egg product-related Salmonella outbreaks in humans. Multilocus variable-number tandem-repeat analysis (MLVA) results indicated that MLVA types detected from human food poisoning cases exhibited MLVA patterns similar to the strains isolated during this study. All Salmonella isolates ( n = 209) were tested for 15 different genes involved in adhesion, invasion, and survival of Salmonella spp. We also observed variations for sopA , ironA , and misL There were no positive correlations between fecal corticosterone metabolite (FCM) and Salmonella prevalence and/or shedding in feces. Also, there were no positive correlations between Salmonella prevalence and Salmonella count (log MPN) and any of the other welfare parameters. IMPORTANCE In this study, the welfare of laying hens and Salmonella shedding were compared over a prolonged period of time in field conditions. This study investigated the long-term shedding of Salmonella serovars in

Predictors and risk factors for the intestinal shedding of Escherichia coli O157 among working donkeys (Equus asinus) in Nigeria

Science.gov (United States)

Jedial, Jesse T.; Shittu, Aminu; Tambuwal, Faruk M.; Abubakar, Mikail B.; Garba, Muhammed K.; Kwaga, Jacob P.; Fasina, Folorunso O.

2015-01-01

Objectives Escherichia coli are an important group of bacteria in the normal gastrointestinal system but can sometimes cause infections in domestic animals and man. Donkeys are routinely used as multipurpose animal but details of burdens of potentially infectious bacteria associated with it are limited. The prevalence and associations between intestinal shedding of E. coli O157 and animal characteristics and management factors were studied among 240 randomly selected working donkeys in north-western Nigeria. Design Four local government areas, of Sokoto State in north-western Nigeria were recruited in this study. A multistage randomised cluster design was used to select subjects and donkey owners within selected zones. Confirmation of infection was based on bacterial culture, isolation and biochemical test for E. coli O157 from faecal samples. Results Of the total bacteria isolated, 203 of the 329 (61.70 per cent) were E. coli, 76 of which was E. coli serotype O157. A multivariable logistic regression model was used to examine the relation between intestinal shedding of E. coli O157 and selected variables. The analysis yielded five potential predictors of shedding: soft faeces in donkeys, Akaza and Fari ecotypes of donkey were positive predictors while maize straw as feed and sampling during the cold dry period were negative predictors. Conclusions This study concludes that controlling intestinal shedding of E. coli O157 among working donkeys in Nigeria is possible using the identified predictors in planning appropriate interventions to reduced human risk of infection. PMID:26392892

Shedding light on baryonic dark matter

Science.gov (United States)

Silk, Joseph

1991-01-01

Halo dark matter, if it is baryonic, may plausibly consist of compact stellar remnants. Jeans mass clouds containing 10 to the 6th to 10 to the 8th solar masses could have efficiently formed stars in the early universe and could plausibly have generated, for a suitably top-heavy stellar initial mass function, a high abundance of neutron stars as well as a small admixture of long-lived low mass stars. Within the resulting clusters of dark remnants, which eventually are tidally disrupted when halos eventually form, captures of neutron stars by nondegenerate stars resulted in formation of close binaries. These evolve to produce, by the present epoch, an observable X-ray signal associated with dark matter aggregations in galaxy cluster cores.

Shedding light on the dark social

DEFF Research Database (Denmark)

Swart, Joëlle; Peters, Chris; Broersma, Marcel

2018-01-01

Messaging apps and Facebook groups are increasingly significant in everyday life, shaping not only interpersonal communication but also how people orient themselves to public life. These “dark social media” are important spaces for “public connection,” a means for bridging people’s private worlds...... with local, work, and leisure-related communities to investigate questions of inclusiveness, engagement, relevance, and constructiveness associated with sharing and discussing news. We find the perceived value of news on dark social media hinges on the control and privacy it provides. Community type was less...

Shedding light on canine pituitary dwarfism

NARCIS (Netherlands)

Voorbij, A.M.W.Y.

2015-01-01

Pituitary dwarfism, associated with growth hormone deficiency, is an autosomal, recessively inherited disorder in shepherd dogs. Due to the serious nature of pituitary dwarfism and lack of efficient treatment, it is preferable to prevent dwarfs from being born by applying a correct breeding policy.

Shedding light on canine pituitary dwarfism

OpenAIRE

Voorbij, A.M.W.Y.

2015-01-01

Pituitary dwarfism, associated with growth hormone deficiency, is an autosomal, recessively inherited disorder in shepherd dogs. Due to the serious nature of pituitary dwarfism and lack of efficient treatment, it is preferable to prevent dwarfs from being born by applying a correct breeding policy. However, because pituitary dwarfism is a recessively inherited disorder and carriers do not differ phenotypically from non-carriers, genetic testing is required to prevent mating of 2 carriers. But...

Shedding Light on Dark Liquidity Pools

NARCIS (Netherlands)

Degryse, H.A.; van Achter, M.; Wuyts, G.

2008-01-01

This article reviews the recent developments on dark liquidity pools starting from the theoretical and empirical academic literature. The number of dark liquidity pools as well as their trading volume has grown substantially in the last couple of years. We highlight the incentives of providers as

Properties of light flavour baryons in hypercentral quark model

Indian Academy of Sciences (India)

Light baryons; magnetic moments; transition magnetic moment; radiative decay width. ... particles are produced by scattering the pion, photon, or electron ... and decuplet) for testing any model hypothesis and understanding the dynamics of ...

Gravitational form factors and angular momentum densities in light-front quark-diquark model

Energy Technology Data Exchange (ETDEWEB)

Kumar, Narinder [Indian Institute of Technology Kanpur, Department of Physics, Kanpur (India); Mondal, Chandan [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China); Sharma, Neetika [I K Gujral Punjab Technical University, Department of Physical Sciences, Jalandhar, Punjab (India); Panjab University, Department of Physics, Chandigarh (India)

2017-12-15

We investigate the gravitational form factors (GFFs) and the longitudinal momentum densities (p{sup +} densities) for proton in a light-front quark-diquark model. The light-front wave functions are constructed from the soft-wall AdS/QCD prediction. The contributions from both the scalar and the axial vector diquarks are considered here. The results are compared with the consequences of a parametrization of nucleon generalized parton distributions (GPDs) in the light of recent MRST measurements of parton distribution functions (PDFs) and a soft-wall AdS/QCD model. The spatial distribution of angular momentum for up and down quarks inside the nucleon has been presented. At the density level, we illustrate different definitions of angular momentum explicitly for an up and down quark in the light-front quark-diquark model inspired by AdS/QCD. (orig.)

Phenomenological study of extended seesaw model for light sterile neutrino

Energy Technology Data Exchange (ETDEWEB)

Nath, Newton [Physical Research Laboratory,Navarangpura, Ahmedabad 380 009 (India); Indian Institute of Technology,Gandhinagar, Ahmedabad-382424 (India); Ghosh, Monojit [Department of Physics, Tokyo Metropolitan University,Hachioji, Tokyo 192-0397 (Japan); Goswami, Srubabati [Physical Research Laboratory,Navarangpura, Ahmedabad 380 009 (India); Gupta, Shivani [Center of Excellence for Particle Physics (CoEPP), University of Adelaide,Adelaide SA 5005 (Australia)

2017-03-14

We study the zero textures of the Yukawa matrices in the minimal extended type-I seesaw (MES) model which can give rise to ∼ eV scale sterile neutrinos. In this model, three right handed neutrinos and one extra singlet S are added to generate a light sterile neutrino. The light neutrino mass matrix for the active neutrinos, m{sub ν}, depends on the Dirac neutrino mass matrix (M{sub D}), Majorana neutrino mass matrix (M{sub R}) and the mass matrix (M{sub S}) coupling the right handed neutrinos and the singlet. The model predicts one of the light neutrino masses to vanish. We systematically investigate the zero textures in M{sub D} and observe that maximum five zeros in M{sub D} can lead to viable zero textures in m{sub ν}. For this study we consider four different forms for M{sub R} (one diagonal and three off diagonal) and two different forms of (M{sub S}) containing one zero. Remarkably we obtain only two allowed forms of m{sub ν} (m{sub eτ}=0 and m{sub ττ}=0) having inverted hierarchical mass spectrum. We re-analyze the phenomenological implications of these two allowed textures of m{sub ν} in the light of recent neutrino oscillation data. In the context of the MES model, we also express the low energy mass matrix, the mass of the sterile neutrino and the active-sterile mixing in terms of the parameters of the allowed Yukawa matrices. The MES model leads to some extra correlations which disallow some of the Yukawa textures obtained earlier, even though they give allowed one-zero forms of m{sub ν}. We show that the allowed textures in our study can be realized in a simple way in a model based on MES mechanism with a discrete Abelian flavor symmetry group Z{sub 8}×Z{sub 2}.

Vortex shedding induced by a solitary wave propagating over a submerged vertical plate

International Nuclear Information System (INIS)

Lin Chang; Ho, T.-C.; Chang, S.-C.; Hsieh, S.-C.; Chang, K.-A.

2005-01-01

Experimental study was conducted on the vortex shedding process induced by the interaction between a solitary wave and a submerged vertical plate. Particle image velocimetry (PIV) was used for quantitative velocity measurement while a particle tracing technique was used for qualitative flow visualization. Vortices are generated at the tip of each side of the plate. The largest vortices at each side of the plate eventually grow to the size of the water depth. Although the fluid motion under the solitary wave is only translatory, vortices are shed in both the upstream and downstream directions due to the interaction of the generated vortices as well as the vortices with the plate and the bottom. The process can be divided into four phases: the formation of a separated shear layer, the generation and shedding of vortices, the formation of a vertical jet, and the impingement of the jet onto the free surface. Similarity velocity profiles were found both in the separated shear layer and in the vertical jet

A garment for use in the operating theatre: the effect upon bacterial shedding.

Science.gov (United States)

Dankert, J; Zijlstra, J B; Lubberding, H

1979-02-01

In operating theatres the air is mainly contaminated with bacteria shed from the human skin. The emission of bacteria can be prevented by wearing clothing of impervious material, while normal cotton clothing does not decrease the shedding of bacteria. In this study shedding of viable bacteria from 20 test-persons wearing an operating theatre suit, composed of 65% polyester and 35% cotton (Diolen), was investigated in a test-chamber and compared with that when normal clothing was worn. The use of this operating-theatre suit resulted in a significant reduction (50--75%) in the number of bacteria-carrying particles in the air of the test-chamber and in an operating room when everyone present wore this suit. A combination of the suit with knee-high boots showed a further reduction in the dispersal of colony forming units. The dispersion from female subjects wearing an operating-theatre frock was significantly higher than when wearing an operating-theatre suit.

Current Concepts for Genital Herpes Simplex Virus Infection: Diagnostics and Pathogenesis of Genital Tract Shedding

Science.gov (United States)

Corey, Lawrence

2015-01-01

SUMMARY Herpes simplex virus 2 (HSV-2) is a DNA virus that is efficiently transmitted through intimate genital tract contact and causes persistent infection that cannot be eliminated. HSV-2 may cause frequent, symptomatic self-limited genital ulcers, but in most persons infection is subclinical. However, recent studies have demonstrated that the virus is frequently shed from genital surfaces even in the absence of signs or symptoms of clinical disease and that the virus can be transmitted during these periods of shedding. Furthermore, HSV-2 shedding is detected throughout the genital tract and may be associated with genital tract inflammation, which likely contributes to increased risk of HIV acquisition. This review focuses on HSV diagnostics, as well as what we have learned about the importance of frequent genital HSV shedding for (i) HSV transmission and (ii) genital tract inflammation, as well as (iii) the impact of HSV-2 infection on HIV acquisition and transmission. We conclude with discussion of future areas of research to push the field forward. PMID:26561565

Current Concepts for Genital Herpes Simplex Virus Infection: Diagnostics and Pathogenesis of Genital Tract Shedding.

Science.gov (United States)

Johnston, Christine; Corey, Lawrence

2016-01-01

Herpes simplex virus 2 (HSV-2) is a DNA virus that is efficiently transmitted through intimate genital tract contact and causes persistent infection that cannot be eliminated. HSV-2 may cause frequent, symptomatic self-limited genital ulcers, but in most persons infection is subclinical. However, recent studies have demonstrated that the virus is frequently shed from genital surfaces even in the absence of signs or symptoms of clinical disease and that the virus can be transmitted during these periods of shedding. Furthermore, HSV-2 shedding is detected throughout the genital tract and may be associated with genital tract inflammation, which likely contributes to increased risk of HIV acquisition. This review focuses on HSV diagnostics, as well as what we have learned about the importance of frequent genital HSV shedding for (i) HSV transmission and (ii) genital tract inflammation, as well as (iii) the impact of HSV-2 infection on HIV acquisition and transmission. We conclude with discussion of future areas of research to push the field forward. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Computational optogenetics: empirically-derived voltage- and light-sensitive channelrhodopsin-2 model.

Directory of Open Access Journals (Sweden)

John C Williams

Full Text Available Channelrhodospin-2 (ChR2, a light-sensitive ion channel, and its variants have emerged as new excitatory optogenetic tools not only in neuroscience, but also in other areas, including cardiac electrophysiology. An accurate quantitative model of ChR2 is necessary for in silico prediction of the response to optical stimulation in realistic tissue/organ settings. Such a model can guide the rational design of new ion channel functionality tailored to different cell types/tissues. Focusing on one of the most widely used ChR2 mutants (H134R with enhanced current, we collected a comprehensive experimental data set of the response of this ion channel to different irradiances and voltages, and used these data to develop a model of ChR2 with empirically-derived voltage- and irradiance- dependence, where parameters were fine-tuned via simulated annealing optimization. This ChR2 model offers: 1 accurate inward rectification in the current-voltage response across irradiances; 2 empirically-derived voltage- and light-dependent kinetics (activation, deactivation and recovery from inactivation; and 3 accurate amplitude and morphology of the response across voltage and irradiance settings. Temperature-scaling factors (Q10 were derived and model kinetics was adjusted to physiological temperatures. Using optical action potential clamp, we experimentally validated model-predicted ChR2 behavior in guinea pig ventricular myocytes. The model was then incorporated in a variety of cardiac myocytes, including human ventricular, atrial and Purkinje cell models. We demonstrate the ability of ChR2 to trigger action potentials in human cardiomyocytes at relatively low light levels, as well as the differential response of these cells to light, with the Purkinje cells being most easily excitable and ventricular cells requiring the highest irradiance at all pulse durations. This new experimentally-validated ChR2 model will facilitate virtual experimentation in neural and

Genital Herpes Simplex Virus Type 2 Shedding Among Adults With and Without HIV Infection in Uganda.

Science.gov (United States)

Phipps, Warren; Nakku-Joloba, Edith; Krantz, Elizabeth M; Selke, Stacy; Huang, Meei-Li; Kambugu, Fred; Orem, Jackson; Casper, Corey; Corey, Lawrence; Wald, Anna

2016-02-01

Despite the high prevalence of herpes simplex virus type 2 (HSV-2) in sub-Saharan Africa, the natural history of infection among Africans is not well characterized. We evaluated the frequency of genital HSV shedding in HIV-seropositive and HIV-seronegative men and women in Uganda. Ninety-three HSV-2-seropositive Ugandan adults collected anogenital swab specimens for HSV DNA quantification by polymerase chain reaction 3 times daily for 6 weeks. HSV-2 was detected from 2484 of 11 283 swab specimens collected (22%), with a median quantity of 4.3 log10 HSV copies/mL (range, 2.2-8.9 log10 HSV copies/mL). Genital lesions were reported on 749 of 3875 days (19%), and subclinical HSV shedding was detected from 1480 of 9113 swab specimens (16%) collected on days without lesions. Men had higher rates of total HSV shedding (relative risk [RR], 2.0 [95% confidence interval {CI}, 1.3-2.9]; P genital lesions (RR, 2.1 [95% CI, 1.2-3.4]; P = .005), compared with women. No differences in shedding rates or lesion frequency were observed based on HIV serostatus. HSV-2 shedding frequency and quantity are high among HSV-2-seropositive adults in sub-Saharan Africa, including persons with and those without HIV infection. Shedding rates were particularly high among men, which may contribute to the high prevalence of HSV-2 and early acquisition among African women. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Computational model of lightness perception in high dynamic range imaging

Science.gov (United States)

Krawczyk, Grzegorz; Myszkowski, Karol; Seidel, Hans-Peter

2006-02-01

An anchoring theory of lightness perception by Gilchrist et al. [1999] explains many characteristics of human visual system such as lightness constancy and its spectacular failures which are important in the perception of images. The principal concept of this theory is the perception of complex scenes in terms of groups of consistent areas (frameworks). Such areas, following the gestalt theorists, are defined by the regions of common illumination. The key aspect of the image perception is the estimation of lightness within each framework through the anchoring to the luminance perceived as white, followed by the computation of the global lightness. In this paper we provide a computational model for automatic decomposition of HDR images into frameworks. We derive a tone mapping operator which predicts lightness perception of the real world scenes and aims at its accurate reproduction on low dynamic range displays. Furthermore, such a decomposition into frameworks opens new grounds for local image analysis in view of human perception.

THE INFORMATION CONTENT IN ANALYTIC SPOT MODELS OF BROADBAND PRECISION LIGHT CURVES

Energy Technology Data Exchange (ETDEWEB)

Walkowicz, Lucianne M. [Department of Astrophysical Sciences, Princeton University, Peyton Hall, 4 Ivy Lane, Princeton, NJ 08534 (United States); Basri, Gibor [Astronomy Department, University of California at Berkeley, Hearst Field Annex, Berkeley, CA 94720 (United States); Valenti, Jeff A. [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States)

2013-04-01

We present the results of numerical experiments to assess degeneracies in light curve models of starspots. Using synthetic light curves generated with the Cheetah starspot modeling code, we explore the extent to which photometric light curves constrain spot model parameters, including spot latitudes and stellar inclination. We also investigate the effects of spot parameters and differential rotation on one's ability to correctly recover rotation periods and differential rotation in the Kepler light curves. We confirm that in the absence of additional constraints on the stellar inclination, such as spectroscopic measurements of vsin i or occultations of starspots by planetary transits, the spot latitude and stellar inclination are difficult to determine uniquely from the photometry alone. We find that for models with no differential rotation, spots that appear on opposite hemispheres of the star may cause one to interpret the rotation period to be half of the true period. When differential rotation is included, the changing longitude separation between spots breaks the symmetry of the hemispheres and the correct rotation period is more likely to be found. The dominant period found via periodogram analysis is typically that of the largest spot. Even when multiple spots with periods representative of the star's differential rotation exist, if one spot dominates the light curve the signal of differential rotation may not be detectable from the periodogram alone. Starspot modeling is applicable to stars with a wider range of rotation rates than other surface imaging techniques (such as Doppler imaging), allows subtle signatures of differential rotation to be measured, and may provide valuable information on the distribution of stellar spots. However, given the inherent degeneracies and uncertainty present in starspot models, caution should be exercised in their interpretation.

THE INFORMATION CONTENT IN ANALYTIC SPOT MODELS OF BROADBAND PRECISION LIGHT CURVES

International Nuclear Information System (INIS)

Walkowicz, Lucianne M.; Basri, Gibor; Valenti, Jeff A.

2013-01-01

We present the results of numerical experiments to assess degeneracies in light curve models of starspots. Using synthetic light curves generated with the Cheetah starspot modeling code, we explore the extent to which photometric light curves constrain spot model parameters, including spot latitudes and stellar inclination. We also investigate the effects of spot parameters and differential rotation on one's ability to correctly recover rotation periods and differential rotation in the Kepler light curves. We confirm that in the absence of additional constraints on the stellar inclination, such as spectroscopic measurements of vsin i or occultations of starspots by planetary transits, the spot latitude and stellar inclination are difficult to determine uniquely from the photometry alone. We find that for models with no differential rotation, spots that appear on opposite hemispheres of the star may cause one to interpret the rotation period to be half of the true period. When differential rotation is included, the changing longitude separation between spots breaks the symmetry of the hemispheres and the correct rotation period is more likely to be found. The dominant period found via periodogram analysis is typically that of the largest spot. Even when multiple spots with periods representative of the star's differential rotation exist, if one spot dominates the light curve the signal of differential rotation may not be detectable from the periodogram alone. Starspot modeling is applicable to stars with a wider range of rotation rates than other surface imaging techniques (such as Doppler imaging), allows subtle signatures of differential rotation to be measured, and may provide valuable information on the distribution of stellar spots. However, given the inherent degeneracies and uncertainty present in starspot models, caution should be exercised in their interpretation.

Mathematical modeling for surface hardness in investment casting applications

International Nuclear Information System (INIS)

Singh, Rupinder

2012-01-01

Investment casting (IC) has many potential engineering applications. Not much work hitherto has been reported for modeling the surface hardness (SH) in IC of industrial components. In the present study, outcome of Taguchi based macro model has been used for developing a mathematical model for SH; using Buckingham's π theorem. Three input parameters namely volume/surface area (V/A) ratio of cast components, slurry layer's combination (LC) and molten metal pouring temperature were selected to give output in form of SH. This study will provide main effects of these variables on SH and will shed light on the SH mechanism in IC. The comparison with experimental results will also serve as further validation of model

Model-checking dense-time Duration Calculus

DEFF Research Database (Denmark)

Fränzle, Martin

2004-01-01

Since the seminal work of Zhou Chaochen, M. R. Hansen, and P. Sestoft on decidability of dense-time Duration Calculus [Zhou, Hansen, Sestoft, 1993] it is well-known that decidable fragments of Duration Calculus can only be obtained through withdrawal of much of the interesting vocabulary...... of this logic. While this was formerly taken as an indication that key-press verification of implementations with respect to elaborate Duration Calculus specifications were also impossible, we show that the model property is well decidable for realistic designs which feature natural constraints...... suitably sparser model classes we obtain model-checking procedures for rich subsets of Duration Calculus. Together with undecidability results also obtained, this sheds light upon the exact borderline between decidability and undecidability of Duration Calculi and related logics....

A dynamical systems analysis of the kinematics of time-periodic vortex shedding past a circular cylinder

Science.gov (United States)

Ottino, Julio M.

1991-01-01

Computer flow simulation aided by dynamical systems analysis is used to investigate the kinematics of time-periodic vortex shedding past a two-dimensional circular cylinder in the context of the following general questions: (1) Is a dynamical systems viewpoint useful in the understanding of this and similar problems involving time-periodic shedding behind bluff bodies; and (2) Is it indeed possible, by adopting such a point of view, to complement previous analyses or to understand kinematical aspects of the vortex shedding process that somehow remained hidden in previous approaches. We argue that the answers to these questions are positive. Results are described.

Molecular epidemiology of Avian Rotaviruses Group A and D shed by different bird species in Nigeria.

Science.gov (United States)

Pauly, Maude; Oni, Oluwole O; Sausy, Aurélie; Owoade, Ademola A; Adeyefa, Christopher A O; Muller, Claude P; Hübschen, Judith M; Snoeck, Chantal J

2017-06-12

Avian rotaviruses (RVs) cause gastrointestinal diseases of birds worldwide. However, prevalence, diversity, epidemiology and phylogeny of RVs remain largely under-investigated in Africa. Fecal samples from 349 birds (158 symptomatic, 107 asymptomatic and 84 birds without recorded health status) were screened by reverse transcription PCR to detect RV groups A and D (RVA and RVD). Partial gene sequences of VP4, VP6, VP7 and NSP4 for RVA, and of VP6 and VP7 for RVD were obtained and analyzed to infer phylogenetic relationship. Fisher's exact test and logistic regression were applied to identify factors potentially influencing virus shedding in chickens. A high prevalence of RVA (36.1%; 126/349) and RVD (31.8%; 111/349) shedding was revealed in birds. In chickens, RV shedding was age-dependent and highest RVD shedding rates were found in commercial farms. No negative health effect could be shown, and RVA and RVD shedding was significantly more likely in asymptomatic chickens: RVA/RVD were detected in 51.9/48.1% of the asymptomatic chickens, compared to 18.9/29.7% of the symptomatic chickens (p epidemiology, diversity and classification of avian RVA and RVD in Nigeria. We show that cross-species transmission of host permissive RV strains occurs when different bird species are mixed.

{theta}-vacua in the light-front quantized Schwinger model

Energy Technology Data Exchange (ETDEWEB)

Srivastava, Prem P. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Fisica]|[Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

1996-09-01

The light-front quantization of the bosonized Schwinger model is discussed in the continuum formulation. The proposal, successfully used earlier for describing the spontaneous symmetry breaking on the light-front, of separating first the scalar field into the dynamical condensate and the fluctuation fields before employing the standard Dirac method works here as well. Some topics on the front form theory are summarized in the Appendices and attention is drawn to the fact that the theory quantized, at x{sup +} seems already to carry information on equal x{sup -} commutators as well. (author). 21 refs.

θ-vacua in the light-front quantized Schwinger model

International Nuclear Information System (INIS)

Srivastava, Prem P.

1996-09-01

The light-front quantization of the bosonized Schwinger model is discussed in the continuum formulation. The proposal, successfully used earlier for describing the spontaneous symmetry breaking on the light-front, of separating first the scalar field into the dynamical condensate and the fluctuation fields before employing the standard Dirac method works here as well. Some topics on the front form theory are summarized in the Appendices and attention is drawn to the fact that the theory quantized, at x + seems already to carry information on equal x - commutators as well. (author). 21 refs

Systematic review of mucosal immunity induced by oral and inactivated poliovirus vaccines against virus shedding following oral poliovirus challenge.

Directory of Open Access Journals (Sweden)

Thomas R Hird

Full Text Available Inactivated poliovirus vaccine (IPV may be used in mass vaccination campaigns during the final stages of polio eradication. It is also likely to be adopted by many countries following the coordinated global cessation of vaccination with oral poliovirus vaccine (OPV after eradication. The success of IPV in the control of poliomyelitis outbreaks will depend on the degree of nasopharyngeal and intestinal mucosal immunity induced against poliovirus infection. We performed a systematic review of studies published through May 2011 that recorded the prevalence of poliovirus shedding in stool samples or nasopharyngeal secretions collected 5-30 days after a "challenge" dose of OPV. Studies were combined in a meta-analysis of the odds of shedding among children vaccinated according to IPV, OPV, and combination schedules. We identified 31 studies of shedding in stool and four in nasopharyngeal samples that met the inclusion criteria. Individuals vaccinated with OPV were protected against infection and shedding of poliovirus in stool samples collected after challenge compared with unvaccinated individuals (summary odds ratio [OR] for shedding 0.13 (95% confidence interval [CI] 0.08-0.24. In contrast, IPV provided no protection against shedding compared with unvaccinated individuals (summary OR 0.81 [95% CI 0.59-1.11] or when given in addition to OPV, compared with individuals given OPV alone (summary OR 1.14 [95% CI 0.82-1.58]. There were insufficient studies of nasopharyngeal shedding to draw a conclusion. IPV does not induce sufficient intestinal mucosal immunity to reduce the prevalence of fecal poliovirus shedding after challenge, although there was some evidence that it can reduce the quantity of virus shed. The impact of IPV on poliovirus transmission in countries where fecal-oral spread is common is unknown but is likely to be limited compared with OPV.

Consistent partnership formation: application to a sexually transmitted disease model.

Science.gov (United States)

Artzrouni, Marc; Deuchert, Eva

2012-02-01

We apply a consistent sexual partnership formation model which hinges on the assumption that one gender's choices drives the process (male or female dominant model). The other gender's behavior is imputed. The model is fitted to UK sexual behavior data and applied to a simple incidence model of HSV-2. With a male dominant model (which assumes accurate male reports on numbers of partners) the modeled incidences of HSV-2 are 77% higher for men and 50% higher for women than with a female dominant model (which assumes accurate female reports). Although highly stylized, our simple incidence model sheds light on the inconsistent results one can obtain with misreported data on sexual activity and age preferences. Copyright © 2011 Elsevier Inc. All rights reserved.

Universal behavior in excited heavy-light and light-light mesons

International Nuclear Information System (INIS)

Olsson, M.G.

1997-01-01

A common pattern of large orbital and radial excitations in heavy-light and light-light mesons is demonstrated. For a general potential model with linear confinement the Regge slopes of the light degrees of freedom for these mesons are shown to be in the ratio of 2. The possibility of 'tower' degeneracy occurs only with pure scalar confinement. copyright 1997 The American Physical Society

Threshold pion photoproduction in A light-cone quark model

International Nuclear Information System (INIS)

Konen, W.; Drechsel, D.

1991-01-01

The instantaneous and seagull graphs are calculated for pion photoproduction in a relativistic light-cone model of the nucleon. In both pseudoscalar and pseudovector coupling we find the ratios A (-) :A (0) :A (+) =1:(-1/2μ):(-9/5 1/2μ) in the nonrelativistic limit. These results correspond to the sum of seagull and Z-graph in the nonrelativistic quark model. In pseudovector coupling also the numerical results for realistic-model parameters are close to those values. (orig.)

A High-Resolution Proteomic Landscaping of Primary Human Dental Stem Cells: Identification of SHED- and PDLSC-Specific Biomarkers

Directory of Open Access Journals (Sweden)

Vasiliki Taraslia

2018-01-01

Full Text Available Dental stem cells (DSCs have emerged as a promising tool for basic research and clinical practice. A variety of adult stem cell (ASC populations can be isolated from different areas within the dental tissue, which, due to their cellular and molecular characteristics, could give rise to different outcomes when used in potential applications. In this study, we performed a high-throughput molecular comparison of two primary human adult dental stem cell (hADSC sub-populations: Stem Cells from Human Exfoliated Deciduous Teeth (SHEDs and Periodontal Ligament Stem Cells (PDLSCs. A detailed proteomic mapping of SHEDs and PDLSCs, via employment of nano-LC tandem-mass spectrometry (MS/MS revealed 2032 identified proteins in SHEDs and 3235 in PDLSCs. In total, 1516 proteins were expressed in both populations, while 517 were unique for SHEDs and 1721 were exclusively expressed in PDLSCs. Further analysis of the recorded proteins suggested that SHEDs predominantly expressed molecules that are involved in organizing the cytoskeletal network, cellular migration and adhesion, whereas PDLSCs are highly energy-producing cells, vastly expressing proteins that are implicated in various aspects of cell metabolism and proliferation. Applying the Rho-GDI signaling pathway as a paradigm, we propose potential biomarkers for SHEDs and for PDLSCs, reflecting their unique features, properties and engaged molecular pathways.

A Crystallographic Study of the Role of Sequence Context in Thymine Glycol Bypass by a Replicative DNA Polymerase Serendipitously Sheds Light on the Exonuclease Complex

Energy Technology Data Exchange (ETDEWEB)

Aller, Pierre; Duclos, Stéphanie; Wallace, Susan S.; Doublié, Sylvie (Vermont)

2012-06-27

Thymine glycol (Tg) is the most common oxidation product of thymine and is known to be a strong block to replicative DNA polymerases. A previously solved structure of the bacteriophage RB69 DNA polymerase (RB69 gp43) in complex with Tg in the sequence context 5'-G-Tg-G shed light on how Tg blocks primer elongation: The protruding methyl group of the oxidized thymine displaces the adjacent 5'-G, which can no longer serve as a template for primer elongation [Aller, P., Rould, M. A., Hogg, M, Wallace, S. S. and Doublie S. (2007). A structural rationale for stalling of a replicative DNA polymerase at the most common oxidative thymine lesion, thymine glycol. Proc. Natl. Acad. Sci. USA, 104, 814-818.]. Several studies showed that in the sequence context 5'-C-Tg-purine, Tg is more likely to be bypassed by Klenow fragment, an A-family DNA polymerase. We set out to investigate the role of sequence context in Tg bypass in a B-family polymerase and to solve the crystal structures of the bacteriophage RB69 DNA polymerase in complex with Tg-containing DNA in the three remaining sequence contexts: 5'-A-Tg-G, 5'-T-Tg-G, and 5'-C-Tg-G. A combination of several factors - including the associated exonuclease activity, the nature of the 3' and 5' bases surrounding Tg, and the cis-trans interconversion of Tg - influences Tg bypass. We also visualized for the first time the structure of a well-ordered exonuclease complex, allowing us to identify and confirm the role of key residues (Phe123, Met256, and Tyr257) in strand separation and in the stabilization of the primer strand in the exonuclease site.

Color design model of high color rendering index white-light LED module.

Science.gov (United States)

Ying, Shang-Ping; Fu, Han-Kuei; Hsieh, Hsin-Hsin; Hsieh, Kun-Yang

2017-05-10

The traditional white-light light-emitting diode (LED) is packaged with a single chip and a single phosphor but has a poor color rendering index (CRI). The next-generation package comprises two chips and a single phosphor, has a high CRI, and retains high luminous efficacy. This study employs two chips and two phosphors to improve the diode's color tunability with various proportions of two phosphors and various densities of phosphor in the silicone used. A color design model is established for color fine-tuning of the white-light LED module. The maximum difference between the measured and color-design-model simulated CIE 1931 color coordinates is approximately 0.0063 around a correlated color temperature (CCT) of 2500 K. This study provides a rapid method to obtain the color fine-tuning of a white-light LED module with a high CRI and luminous efficacy.

Light hadrons in the bag model with broken chiral symmetry

International Nuclear Information System (INIS)

Efrosinin, V.P.; Zaikin, D.A.

1987-01-01

A version of the bag model with broken chiral symmetry is proposed. A satisfactory description of the experimental data on light hadrons including the pion is obtained. The estimate of the pion-nucleon σ term is given in the framework of this model. The pion and kaon decay constants are calculated. The centre-of-mass motion problem in bag models is discussed

Voltage Stability Control of Electrical Network Using Intelligent Load Shedding Strategy Based on Fuzzy Logic

Directory of Open Access Journals (Sweden)

Houda Jouini

2010-01-01

Full Text Available As a perspective to ensure the power system stability and to avoid the vulnerability leading to the blackouts, several preventive and curative means are adopted. In order to avoid the voltage collapse, load shedding schemes represent a suitable action to maintain the power system service quality and to control its vulnerability. In this paper, we try to propose an intelligent load shedding strategy as a new approach based on fuzzy controllers. This strategy was founded on the calculation of generated power sensitivity degree related to those injected at different network buses. During the fault phase, fuzzy controller algorithms generate monitor vectors ensuring a precalculated load shedding ratio in the purpose to reestablish the power balance and conduct the network to a new steady state.

Skipper genome sheds light on unique phenotypic traits and phylogeny.

Science.gov (United States)

Cong, Qian; Borek, Dominika; Otwinowski, Zbyszek; Grishin, Nick V

2015-08-27

Butterflies and moths are emerging as model organisms in genetics and evolutionary studies. The family Hesperiidae (skippers) was traditionally viewed as a sister to other butterflies based on its moth-like morphology and darting flight habits with fast wing beats. However, DNA studies suggest that the family Papilionidae (swallowtails) may be the sister to other butterflies including skippers. The moth-like features and the controversial position of skippers in Lepidoptera phylogeny make them valuable targets for comparative genomics. We obtained the 310 Mb draft genome of the Clouded Skipper (Lerema accius) from a wild-caught specimen using a cost-effective strategy that overcomes the high (1.6 %) heterozygosity problem. Comparative analysis of Lerema accius and the highly heterozygous genome of Papilio glaucus revealed differences in patterns of SNP distribution, but similarities in functions of genes that are enriched in non-synonymous SNPs. Comparison of Lepidoptera genomes revealed possible molecular bases for unique traits of skippers: a duplication of electron transport chain components could result in efficient energy supply for their rapid flight; a diversified family of predicted cellulases might allow them to feed on cellulose-enriched grasses; an expansion of pheromone-binding proteins and enzymes for pheromone synthesis implies a more efficient mate-recognition system, which compensates for the lack of clear visual cues due to the similarities in wing colors and patterns of many species of skippers. Phylogenetic analysis of several Lepidoptera genomes suggested that the position of Hesperiidae remains uncertain as the tree topology varied depending on the evolutionary model. Completion of the first genome from the family Hesperiidae allowed comparative analyses with other Lepidoptera that revealed potential genetic bases for the unique phenotypic traits of skippers. This work lays the foundation for future experimental studies of skippers and

An implementation of particle swarm optimization to evaluate optimal under-voltage load shedding in competitive electricity markets

Science.gov (United States)

Hosseini-Bioki, M. M.; Rashidinejad, M.; Abdollahi, A.

2013-11-01

Load shedding is a crucial issue in power systems especially under restructured electricity environment. Market-driven load shedding in reregulated power systems associated with security as well as reliability is investigated in this paper. A technoeconomic multi-objective function is introduced to reveal an optimal load shedding scheme considering maximum social welfare. The proposed optimization problem includes maximum GENCOs and loads' profits as well as maximum loadability limit under normal and contingency conditions. Particle swarm optimization (PSO) as a heuristic optimization technique, is utilized to find an optimal load shedding scheme. In a market-driven structure, generators offer their bidding blocks while the dispatchable loads will bid their price-responsive demands. An independent system operator (ISO) derives a market clearing price (MCP) while rescheduling the amount of generating power in both pre-contingency and post-contingency conditions. The proposed methodology is developed on a 3-bus system and then is applied to a modified IEEE 30-bus test system. The obtained results show the effectiveness of the proposed methodology in implementing the optimal load shedding satisfying social welfare by maintaining voltage stability margin (VSM) through technoeconomic analyses.

Organic Light-Emitting Transistors: Materials, Device Configurations, and Operations.

Science.gov (United States)

Zhang, Congcong; Chen, Penglei; Hu, Wenping

2016-03-09

Organic light-emitting transistors (OLETs) represent an emerging class of organic optoelectronic devices, wherein the electrical switching capability of organic field-effect transistors (OFETs) and the light-generation capability of organic light-emitting diodes (OLEDs) are inherently incorporated in a single device. In contrast to conventional OFETs and OLEDs, the planar device geometry and the versatile multifunctional nature of OLETs not only endow them with numerous technological opportunities in the frontier fields of highly integrated organic electronics, but also render them ideal scientific scaffolds to address the fundamental physical events of organic semiconductors and devices. This review article summarizes the recent advancements on OLETs in light of materials, device configurations, operation conditions, etc. Diverse state-of-the-art protocols, including bulk heterojunction, layered heterojunction and laterally arranged heterojunction structures, as well as asymmetric source-drain electrodes, and innovative dielectric layers, which have been developed for the construction of qualified OLETs and for shedding new and deep light on the working principles of OLETs, are highlighted by addressing representative paradigms. This review intends to provide readers with a deeper understanding of the design of future OLETs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Should we assess climate model predictions in light of severe tests?

Science.gov (United States)

Katzav, Joel

2011-06-01

According to Austro-British philosopher Karl Popper, a system of theoretical claims is scientific only if it is methodologically falsifiable, i.e., only if systematic attempts to falsify or severely test the system are being carried out [Popper, 2005, pp. 20, 62]. He holds that a test of a theoretical system is severe if and only if it is a test of the applicability of the system to a case in which the system's failure is likely in light of background knowledge, i.e., in light of scientific assumptions other than those of the system being tested [Popper, 2002, p. 150]. Popper counts the 1919 tests of general relativity's then unlikely predictions of the deflection of light in the Sun's gravitational field as severe. An implication of Popper's above condition for being a scientific theoretical system is the injunction to assess theoretical systems in light of how well they have withstood severe testing. Applying this injunction to assessing the quality of climate model predictions (CMPs), including climate model projections, would involve assigning a quality to each CMP as a function of how well it has withstood severe tests allowed by its implications for past, present, and nearfuture climate or, alternatively, as a function of how well the models that generated the CMP have withstood severe tests of their suitability for generating the CMP.

Effect of a probiotic on prevention of diarrhea and Clostridium difficile and Clostridium perfringens shedding in foals

DEFF Research Database (Denmark)

Schoster, Angelika; Staempfli, H R; Abrahams, M

2015-01-01

of incidence and duration of diarrhea and fecal shedding of Clostridium perfringens and Clostridium difficile between treatment and age groups. RESULTS: The overall incidence of diarrhea was 41 of 72 (59%) and did not differ (P = 0.37) between treatment groups. Foals treated with probiotics were more likely...... of C. perfringens shedding was 55% with no difference between treatment groups (P = 0.23). The prevalence of C. difficile shedding was 11%. CONCLUSION AND CLINICAL IMPORTANCE: There was no benefit of administering a 3-week course of probiotics, but potential adverse effects were noted. Whether...

Hybrid light transport model based bioluminescence tomography reconstruction for early gastric cancer detection

Science.gov (United States)

Chen, Xueli; Liang, Jimin; Hu, Hao; Qu, Xiaochao; Yang, Defu; Chen, Duofang; Zhu, Shouping; Tian, Jie

2012-03-01

Gastric cancer is the second cause of cancer-related death in the world, and it remains difficult to cure because it has been in late-stage once that is found. Early gastric cancer detection becomes an effective approach to decrease the gastric cancer mortality. Bioluminescence tomography (BLT) has been applied to detect early liver cancer and prostate cancer metastasis. However, the gastric cancer commonly originates from the gastric mucosa and grows outwards. The bioluminescent light will pass through a non-scattering region constructed by gastric pouch when it transports in tissues. Thus, the current BLT reconstruction algorithms based on the approximation model of radiative transfer equation are not optimal to handle this problem. To address the gastric cancer specific problem, this paper presents a novel reconstruction algorithm that uses a hybrid light transport model to describe the bioluminescent light propagation in tissues. The radiosity theory integrated with the diffusion equation to form the hybrid light transport model is utilized to describe light propagation in the non-scattering region. After the finite element discretization, the hybrid light transport model is converted into a minimization problem which fuses an l1 norm based regularization term to reveal the sparsity of bioluminescent source distribution. The performance of the reconstruction algorithm is first demonstrated with a digital mouse based simulation with the reconstruction error less than 1mm. An in situ gastric cancer-bearing nude mouse based experiment is then conducted. The primary result reveals the ability of the novel BLT reconstruction algorithm in early gastric cancer detection.

Comparison of three light doses in the photodynamic treatment of actinic keratosis using mathematical modeling

Science.gov (United States)

Vignion-Dewalle, Anne-Sophie; Betrouni, Nacim; Tylcz, Jean-Baptiste; Vermandel, Maximilien; Mortier, Laurent; Mordon, Serge

2015-05-01

Photodynamic therapy (PDT) is an emerging treatment modality for various diseases, especially for cancer therapy. Although high efficacy is demonstrated for PDT using standardized protocols in nonhyperkeratotic actinic keratoses, alternative light doses expected to increase efficiency, to reduce adverse effects or to expand the use of PDT, are still being evaluated and refined. We propose a comparison of the three most common light doses in the treatment of actinic keratosis with 5-aminolevulinic acid PDT through mathematical modeling. The proposed model is based on an iterative procedure that involves determination of the local fluence rate, updating of the local optical properties, and estimation of the local damage induced by the therapy. This model was applied on a simplified skin sample model including an actinic keratosis lesion, with three different light doses (red light dose, 37 J/cm2, 75 mW/cm2, 500 s blue light dose, 10 J/cm2, 10 mW/cm2, 1000 s and daylight dose, 9000 s). Results analysis shows that the three studied light doses, although all efficient, lead to variable local damage. Defining reference damage enables the nonoptimal parameters for the current light doses to be refined and the treatment to be more suitable.

Wind Forced Variability in Eddy Formation, Eddy Shedding, and the Separation of the East Australian Current

Science.gov (United States)

Bull, Christopher Y. S.; Kiss, Andrew E.; Jourdain, Nicolas C.; England, Matthew H.; van Sebille, Erik

2017-12-01

The East Australian Current (EAC), like many other subtropical western boundary currents, is believed to be penetrating further poleward in recent decades. Previous observational and model studies have used steady state dynamics to relate changes in the westerly winds to changes in the separation behavior of the EAC. As yet, little work has been undertaken on the impact of forcing variability on the EAC and Tasman Sea circulation. Here using an eddy-permitting regional ocean model, we present a suite of simulations forced by the same time-mean fields, but with different atmospheric and remote ocean variability. These eddy-permitting results demonstrate the nonlinear response of the EAC to variable, nonstationary inhomogeneous forcing. These simulations show an EAC with high intrinsic variability and stochastic eddy shedding. We show that wind stress variability on time scales shorter than 56 days leads to increases in eddy shedding rates and southward eddy propagation, producing an increased transport and southward reach of the mean EAC extension. We adopt an energetics framework that shows the EAC extension changes to be coincident with an increase in offshore, upstream eddy variance (via increased barotropic instability) and increase in subsurface mean kinetic energy along the length of the EAC. The response of EAC separation to regional variable wind stress has important implications for both past and future climate change studies.

Factors associated with Salmonella shedding among equine colic patients at a veterinary teaching hospital.

Science.gov (United States)

Kim, L M; Morley, P S; Traub-Dargatz, J L; Salman, M D; Gentry-Weeks, C

2001-03-01

To evaluate factors potentially associated with fecal Salmonella shedding among equine patients hospitalized for colic at a veterinary teaching hospital and to determine the effects of probiotic treatment on fecal Salmonella shedding and clinical signs. Longitudinal study and controlled trial. 246 equine colic patients. History and medical information were obtained from patient records. Fecal and environmental samples were submitted for aerobic bacterial culture for Salmonella enterica. Fifty-one patients were treated with a commercially available probiotic; 46 were treated with a placebo. Logistic regression was used to evaluate data. Salmonella organisms were detected in feces from 23 (9%) patients at least once during hospitalization. Patients were more likely to shed Salmonella organisms if diarrhea was evident equine patients hospitalized at a veterinary teaching hospital because of colic and that pathogen monitoring in patients and the hospital environment and use of barrier nursing precautions for equine colic patients are beneficial.

Extended viral shedding of a low pathogenic avian influenza virus by striped skunks (Mephitis mephitis.

Directory of Open Access Journals (Sweden)

J Jeffrey Root

Full Text Available BACKGROUND: Striped skunks (Mephitis mephitis are susceptible to infection with some influenza A viruses. However, the viral shedding capability of this peri-domestic mammal and its potential role in influenza A virus ecology are largely undetermined. METHODOLOGY/PRINCIPAL FINDINGS: Striped skunks were experimentally infected with a low pathogenic (LP H4N6 avian influenza virus (AIV and monitored for 20 days post infection (DPI. All of the skunks exposed to H4N6 AIV shed large quantities of viral RNA, as detected by real-time RT-PCR and confirmed for live virus with virus isolation, from nasal washes and oral swabs (maximum ≤ 10(6.02 PCR EID50 equivalent/mL and ≤ 10(5.19 PCR EID50 equivalent/mL, respectively. Some evidence of potential fecal shedding was also noted. Following necropsy on 20 DPI, viral RNA was detected in the nasal turbinates of one individual. All treatment animals yielded evidence of a serological response by 20 DPI. CONCLUSIONS/SIGNIFICANCE: These results indicate that striped skunks have the potential to shed large quantities of viral RNA through the oral and nasal routes following exposure to a LP AIV. Considering the peri-domestic nature of these animals, along with the duration of shedding observed in this species, their presence on poultry and waterfowl operations could influence influenza A virus epidemiology. For example, this species could introduce a virus to a naive poultry flock or act as a trafficking mechanism of AIV to and from an infected poultry flock to naive flocks or wild bird populations.

Genital Shedding of Herpes Simplex Virus Among Symptomatic and Asymptomatic Persons with HSV-2 Infection

Science.gov (United States)

Tronstein, Elizabeth; Johnston, Christine; Huang, Meei-Li; Selke, Stacy; Magaret, Amalia; Warren, Terri; Corey, Lawrence; Wald, Anna

2011-01-01

Context Since HSV-2 antibody tests have become commercially available, an increasing number of persons learn that they have genital herpes through serologic testing. The course of natural history of HSV-2 in asymptomatic, seropositive persons is uncertain. Objective To evaluate the virologic and clinical course of HSV genital shedding among participants with symptomatic and asymptomatic HSV-2 infection. Design, Setting and Participants Cohort of 498 immunocompetent HSV-2 seropositive persons enrolled in prospective studies of genital HSV shedding at the University of Washington Virology Research Clinic, Seattle, Washington, and Westover Heights Clinic in Portland, Oregon, between 1992 and 2008. Each participant obtained daily self-collected swabs of genital secretions for ≥ 30 days. Main Outcome Measurement The rate of viral shedding measured by quantitative real-time fluorescence polymerase chain reaction (PCR) for HSV DNA from genital swabs. Results HSV was detected on 4,753 of 23,683 days (20.1%; 95% CI, 18.3 to 22.0) in persons with symptomatic genital HSV-2 infection compared with 519 of 5,070 days (10.2%; 95% CI, 7.7 to 13.6) in persons with asymptomatic infection, pgenital viral shedding among persons with symptomatic genital HSV-2 infection compared with 85 of 519 days (16.4%; 95% CI, 11.2 to 23.9) among persons with asymptomatic infection, pgenital tract less frequently than persons with symptomatic infection, but much of the difference is attributable to less frequent genital lesions, as lesions are accompanied by frequent viral shedding. PMID:21486977

A Search for Beyond Standard Model Light Bosons Decaying into Muon Pairs

CERN Document Server

CMS Collaboration

2016-01-01

A dataset corresponding to $2.8~\\mathrm{fb}^{-1}$ of proton-proton collisions at $\\sqrt{s} = 13~\\mathrm{TeV}$ was recorded by the CMS experiment at the CERN LHC. These data are used to search for new light bosons with a mass in the range $0.25-8.5~\\mathrm{GeV}/c^2$ decaying into muon pairs. No excess is observed in the data, and a model-independent upper limit on the product of the cross section, branching fraction and acceptance is derived. The results are interpreted in the context of two benchmark models, namely, the next-to-minimal supersymmetric standard model, and dark SUSY models including those predicting a non-negligible light boson lifetime.

Acoustically levitated dancing drops: Self-excited oscillation to chaotic shedding

Science.gov (United States)

Lin, Po-Cheng; I, Lin

2016-02-01

We experimentally demonstrate self-excited oscillation and shedding of millimeter-sized water drops, acoustically levitated in a single-node standing waves cavity, by decreasing the steady acoustic wave intensity below a threshold. The perturbation of the acoustic field by drop motion is a possible source for providing an effective negative damping for sustaining the growing amplitude of the self-excited motion. Its further interplay with surface tension, drop inertia, gravity and acoustic intensities, select various self-excited modes for different size of drops and acoustic intensity. The large drop exhibits quasiperiodic motion from a vertical mode and a zonal mode with growing coupling, as oscillation amplitudes grow, until falling on the floor. For small drops, chaotic oscillations constituted by several broadened sectorial modes and corresponding zonal modes are self-excited. The growing oscillation amplitude leads to droplet shedding from the edges of highly stretched lobes, where surface tension no longer holds the rapid expanding flow.

Emergency Load Shedding Strategy Based on Sensitivity Analysis of Relay Operation Margin against Cascading Events

DEFF Research Database (Denmark)

Liu, Zhou; Chen, Zhe; Sun, Haishun Sun

2012-01-01

the runtime emergent states of related system component. Based on sensitivity analysis between the relay operation margin and power system state variables, an optimal load shedding strategy is applied to adjust the emergent states timely before the unwanted relay operation. Load dynamics is also taken...... into account to compensate load shedding amount calculation. And the multi-agent technology is applied for the whole strategy implementation. A test system is built in real time digital simulator (RTDS) and has demonstrated the effectiveness of the proposed strategy.......In order to prevent long term voltage instability and induced cascading events, a load shedding strategy based on the sensitivity of relay operation margin to load powers is discussed and proposed in this paper. The operation margin of critical impedance backup relay is defined to identify...

Continuous business model innovation in the Danish newspaper industry

DEFF Research Database (Denmark)

Holm, Anna B.; Günzel, Franziska

Business model innovation is undoubtedly of strategic importance in innovation management. However, little is known on how in fact how companies experiment and innovate with regards to their business models. To shed more light on this issue, we have conducted a qualitative study of the newspaper...... industry in Denmark. Business model innovation became imperative for the traditional newspaper publishers after many years of the declining readership and revenues. We collected rich primary and secondary data from various sources during 2010-2012. Our analysis suggests that changing business models in its...... various parts does not guarantee a successful business model change and may even harm the existing well-functioning business model. To innovate a business model successfully, managers need to secure the business logic flow and its feedback loops....

A Composite Light Curve Model of the Symbiotic Nova PU Vul (1979

Directory of Open Access Journals (Sweden)

Kato M.

2012-06-01

Full Text Available PU Vul (1979 is a symbiotic nova that shows a long-lasting flat optical peak followed by a slow decline. We made a quasi-evolution model for outbursts on a 0.6 M⊙ white dwarf consisting of a series of static solutions with optically-thin winds. Our theoretical models reproduce well the observed visual/UV light curves as well as the new estimates of the temperature and radius of the hot component. We also modeled the light curve of the 1980 and 1994 eclipses as the total eclipse occulted by a pulsating M-giant companion star. In the second eclipse, the visual magnitude is dominated by nebular emission which is possibly ejected from the hot component between 1990 to 2000. We have quantitatively estimated three components of emission, i.e., the white dwarf, companion and nebular, and made a composite light curve that represents well the evolution of the PU Vul outburst.

Coxiella burnetii Shedding Routes and Antibody Response after Outbreaks of Q Fever-Induced Abortion in Dairy Goat Herds▿

OpenAIRE

Rousset, Elodie; Berri, Mustapha; Durand, Benoit; Dufour, Philippe; Prigent, Myriam; Delcroix, Thibault; Touratier, Anne; Rodolakis, Annie

2008-01-01

Q fever is a zoonosis caused by Coxiella burnetii, a bacterium largely carried by ruminants and shed into milk, vaginal mucus, and feces. The main potential hazard to humans and animals is due to shedding of bacteria that can then persist in the environment and be aerosolized. The purpose of this study was to evaluate shedding after an outbreak of Q fever abortion in goat herds and to assess the relationship with the occurrence of abortions and antibody responses. Aborting and nonaborting goa...

Teaching: in light of Noel Gough's and Ajay Sharma's articles

Science.gov (United States)

Pouliot, Chantal

2017-12-01

In their articles, Ajay Sharma (Cult Stud Sci Educ, doi: 10.1007/s11422-017-9835-z, 2017) and Noel Gough (Cult Stud Sci Educ, doi: 10.1007/s11422-017-9834-0, 2017) shed light on the impact neoliberalism has on the teaching of science and suggest ways to ensure that science education remains critical and socially equitable. In this paper, I illustrate how their proposals influenced my instructional choices during the fall of 2016 in a course entitled Epistemology and Education.

Bringing light into darkness

Directory of Open Access Journals (Sweden)

Dorothea McEwan

2015-11-01

Full Text Available The art historian Fritz Saxl, Aby Warburg’s librarian and trusted friend, researched apart from art historical topics images of gods of late antiquity, Oriental and Greek mystery cults and the pictorial presentation of dialogue in early Christian art. This research led him to Mithraism, the images and practices of this mystery cult and in particular how Oriental thought flowed into Occidental thought. Saxl was engaged in this work for many years. In this article I touch upon Saxl’s extended correspondence with Aby Warburg in 1929, when Warburg was in Rome and was able to see Mithraic temples for himself. The exchange of their queries and tentative answers, their theoretical speculations and findings, their approach to understanding Mithraic monuments and sites, shed light on their unique method of scholarly collaboration.

Light pollution: measuring and modelling skyglow. An application in two Portuguese reserves

Science.gov (United States)

Lima, Raul Cerveira Pinto Sousa

Outdoors human-made lighting at night causes sky glow, one of the effects of light pollution. Sky glow is rising with the growth of world population. Urban inhabitants are increasingly deprived from a starry sky. However, since light propagates to regions far from where it is produced, light pollution spreads to places where few or none artificial light at night existed, disturbing the quality of the night sky. In this work we assess for the first time the sky brightness of two regions in Portugal, the Peneda-Geres National Park, and the recently created Starlight Reserve Dark Sky® Alqueva. We used a portable unit, a Unihedron Sky Quality Meter-L (SQM-L), to measure the luminance of the night sky. We also tested the SQM-L in a laboratory to a more thorough analysis of the device, and to check the effect of polarization on the unit, suggested by our observations and other users. Our results suggest that the SQM-L is not affected by any measurable effect of polarization, but some guidelines to use the SQM-L in the field are provided based on our work. The data from the field measurement was used to compare to one light pollution propagation model (Kocifaj, 2007), using VIIRS DNB satellite upwards radiance as input to the model. The results obtained from the model are favourably compared to the field measurements. We proceeded to a set of tests with the model to find the best fit. Our best results were achieved by analysing the data by night rather than the global set of data. Our first results were used to apply to the classification of the region of Alqueva to a Starlight Tourism Destination. That classification was attained during the course of this work (December 2011). A guideline on the Peneda-Geres National Park was also implemented after our first results were provided. We believe we have achieved a set of results in a set of parallel issues all related to light pollution that we hope may contribute to the current knowledge on this area of research.

EDGE EFFECT MODELING AND STUDY FOR THREE-CHIP RGB LIGHT-EMITTING DIODES

Directory of Open Access Journals (Sweden)

A. I. Podosinnikov

2015-03-01

Full Text Available Subject of study. The paper deals with light quality improvement of multi–chip RGB light-emitting diodes (LEDs and luminaries on their basis. In particular, we have studied the issues of the edge effect reducing, which is non–uniformity of color when observing the source of light under different angles as well as non-uniformity of color distribution on the illuminated surface. Methods. Experimental study of the edge effect has been performed, namely, the analysis of the halo at the periphery of the illuminated area and the non–uniformity of area at the surface of the screen illuminated with RGB LEDs with and without light concentrators. Modeling of illumination distribution at various distances from the source for the system containing four RGB LEDs with reflectors by ZEMAX software has been carried out. Assessment of the uniformity for light distribution via calculating the chromaticity coordinates has been performed. Main results. The possibility of modeling application at the stage of a luminary design is shown on the example of RGB LEDs for assessing the efficiency of light flux usage and colorimetric parameters. Suggested method simplifies significantly the design of luminaries and reduces associated costs. Practical relevance. The findings can be used in the design of luminaries based on RGB LEDs, including the ones with secondary optics elements.

The Influence of Load Shedding on the Productivity of Hotel Staff in Cape Town, South Africa

Directory of Open Access Journals (Sweden)

Henriëtte STEENKAMP

2016-07-01

Full Text Available In South Africa, ESCOM is the country’s main electricity supplier. Since 2008, Eskom has implemented load shedding on an ongoing basis as a result of insufficient electricity supply to meet the demands of all its customers. Owing to the fact that many organisations across South Africa are depended on electricity in order to function, previous research studies show that the wide-spread impact of load shedding has had an adverse on the sustainability of many of these organisations. Among these organisations are those based in the hospitality industry – imperative in relation to the stimulation of the national economy; directly related to tourism. Albeit the aforementioned, the sustainability of organisations in the hospitality industry is also heavily dependent on the productivity of their employees. For this research study the influence of load shedding on the productivity of the staff in the hospitality industry was investigated within one particular hotel (Hotel X based in Cape Town. Empirical research was deployed, making use of a mixed methods approach to obtain both quantitative data and qualitative data from respondents. Stemming from the findings it was found that load shedding did have an adverse influence on the productivity of staff in Hotel X, despite the fact that affordable measures were put in place to mitigate the disruptions caused by load shedding. Moreover, the latter dispensation was found to have an inadvertently adverse influence on the overall sustainability of Hotel X on the long run.

A Lagrangian analysis of a two-dimensional airfoil with vortex shedding

Energy Technology Data Exchange (ETDEWEB)

Lipinski, Doug; Cardwell, Blake; Mohseni, Kamran [Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO 80309-0429 (United States)], E-mail: Mohseni@colorado.edu

2008-08-29

Using invariant material manifolds and flow topology, the flow behavior and structure of flow around a two-dimensional Eppler 387 airfoil is examined with an emphasis on vortex shedding and the time-dependent reattachment profile. The examination focuses on low Reynolds number (Re = 60 000) flow at several angles of attack. Using specialized software, we identify invariant manifolds in the flow and use these structures to illuminate the process of vortex formation and the periodic behavior of the reattachment profile. Our analysis concludes with a topological view of the flow, including fixed points and a discussion of phase plots and the frequency spectrum of several key points in the flow. The behavior of invariant manifolds directly relates to the flow topology and illuminates some aspects seen in phase space during vortex shedding. Furthermore, it highlights the reattachment behavior in ways not seen before.

A Lagrangian analysis of a two-dimensional airfoil with vortex shedding

International Nuclear Information System (INIS)

Lipinski, Doug; Cardwell, Blake; Mohseni, Kamran

2008-01-01

Using invariant material manifolds and flow topology, the flow behavior and structure of flow around a two-dimensional Eppler 387 airfoil is examined with an emphasis on vortex shedding and the time-dependent reattachment profile. The examination focuses on low Reynolds number (Re = 60 000) flow at several angles of attack. Using specialized software, we identify invariant manifolds in the flow and use these structures to illuminate the process of vortex formation and the periodic behavior of the reattachment profile. Our analysis concludes with a topological view of the flow, including fixed points and a discussion of phase plots and the frequency spectrum of several key points in the flow. The behavior of invariant manifolds directly relates to the flow topology and illuminates some aspects seen in phase space during vortex shedding. Furthermore, it highlights the reattachment behavior in ways not seen before

Practical investigation for road lighting using renewable energy sources "Sizing and modelling of solar/wind hybrid system for road lighting application"

Directory of Open Access Journals (Sweden)

Maged A. Abu Adma

2017-12-01

Full Text Available This study explains a design of a fully independent -off grid- hybrid solar and wind road lighting system according to geography and weather conditions recorded from the Egyptian National Research Institute of Astronomy and Geophysics.Presenting here the virtual simulation by using Matlab/Simulink & real-time implementation of road lighting system consists of 150 W photovoltaic cell, 420 W wind generator, 100 Ah acid gel battery and LED lighting luminar 30 W -12 VDC . Over three different stages; 1.Operating the system with PV only as power source, 2. Switching to Wind generator only configuration and 3.  Running the hybrid design with both PV & Wind power sources ; load characteristics and output real-time data will be recorded, evaluated ,compared  and validated against the virtual simulation generated by Matlab/Simulink model.The results of this research will be used to investigate the advantages of using a hybrid system to counteract the limitations of solar and wind as solo renewable energy sources due to adverse weather conditions ,the efficiency of the proposed system as an alternative for the current conventional road lighting poles as well as the accuracy of the virtual model data in order to be used for future adaptation of the model for different geographical locations.

The N domain of somatic angiotensin-converting enzyme negatively regulates ectodomain shedding and catalytic activity.

Science.gov (United States)

Woodman, Zenda L; Schwager, Sylva L U; Redelinghuys, Pierre; Carmona, Adriana K; Ehlers, Mario R W; Sturrock, Edward D

2005-08-01

sACE (somatic angiotensin-converting enzyme) consists of two homologous, N and C domains, whereas the testis isoenzyme [tACE (testis ACE)] consists of a single C domain. Both isoenzymes are shed from the cell surface by a sheddase activity, although sACE is shed much less efficiently than tACE. We hypothesize that the N domain of sACE plays a regulatory role, by occluding a recognition motif on the C domain required for ectodomain shedding and by influencing the catalytic efficiency. To test this, we constructed two mutants: CNdom-ACE and CCdom-ACE. CNdom-ACE was shed less efficiently than sACE, whereas CCdom-ACE was shed as efficiently as tACE. Notably, cleavage occurred both within the stalk and the interdomain bridge in both mutants, suggesting that a sheddase recognition motif resides within the C domain and is capable of directly cleaving at both positions. Analysis of the catalytic properties of the mutants and comparison with sACE and tACE revealed that the k(cat) for sACE and CNdom-ACE was less than or equal to the sum of the kcat values for tACE and the N-domain, suggesting negative co-operativity, whereas the kcat value for the CCdom-ACE suggested positive co-operativity between the two domains. Taken together, the results provide support for (i) the existence of a sheddase recognition motif in the C domain and (ii) molecular flexibility of the N and C domains in sACE, resulting in occlusion of the C-domain recognition motif by the N domain as well as close contact of the two domains during hydrolysis of peptide substrates.

Analysing, Interpreting, and Testing the Invariance of the Actor-Partner Interdependence Model

Directory of Open Access Journals (Sweden)

Gareau, Alexandre

2016-09-01

Full Text Available Although in recent years researchers have begun to utilize dyadic data analyses such as the actor-partner interdependence model (APIM, certain limitations to the applicability of these models still exist. Given the complexity of APIMs, most researchers will often use observed scores to estimate the model's parameters, which can significantly limit and underestimate statistical results. The aim of this article is to highlight the importance of conducting a confirmatory factor analysis (CFA of equivalent constructs between dyad members (i.e. measurement equivalence/invariance; ME/I. Different steps for merging CFA and APIM procedures will be detailed in order to shed light on new and integrative methods.

Beam-based model of broad-band impedance of the Diamond Light Source

Science.gov (United States)

Smaluk, Victor; Martin, Ian; Fielder, Richard; Bartolini, Riccardo

2015-06-01

In an electron storage ring, the interaction between a single-bunch beam and a vacuum chamber impedance affects the beam parameters, which can be measured rather precisely. So we can develop beam-based numerical models of longitudinal and transverse impedances. At the Diamond Light Source (DLS) to get the model parameters, a set of measured data has been used including current-dependent shift of betatron tunes and synchronous phase, chromatic damping rates, and bunch lengthening. A matlab code for multiparticle tracking has been developed. The tracking results and analytical estimations are quite consistent with the measured data. Since Diamond has the shortest natural bunch length among all light sources in standard operation, the studies of collective effects with short bunches are relevant to many facilities including next generation of light sources.

Beam-based model of broad-band impedance of the Diamond Light Source

Directory of Open Access Journals (Sweden)

Victor Smaluk

2015-06-01

Full Text Available In an electron storage ring, the interaction between a single-bunch beam and a vacuum chamber impedance affects the beam parameters, which can be measured rather precisely. So we can develop beam-based numerical models of longitudinal and transverse impedances. At the Diamond Light Source (DLS to get the model parameters, a set of measured data has been used including current-dependent shift of betatron tunes and synchronous phase, chromatic damping rates, and bunch lengthening. A matlab code for multiparticle tracking has been developed. The tracking results and analytical estimations are quite consistent with the measured data. Since Diamond has the shortest natural bunch length among all light sources in standard operation, the studies of collective effects with short bunches are relevant to many facilities including next generation of light sources.

Shedding of Ebola Virus Surface Glycoprotein Is a Mechanism of Self-regulation of Cellular Cytotoxicity and Has a Direct Effect on Virus Infectivity.

Science.gov (United States)

Dolnik, Olga; Volchkova, Valentina A; Escudero-Perez, Beatriz; Lawrence, Philip; Klenk, Hans-Dieter; Volchkov, Viktor E

2015-10-01

The surface glycoprotein (GP) is responsible for Ebola virus (EBOV) attachment and membrane fusion during virus entry. Surface expression of highly glycosylated GP causes marked cytotoxicity via masking of a wide range of cellular surface molecules, including integrins. Considerable amounts of surface GP are shed from virus-infected cells in a soluble truncated form by tumor necrosis factor α-converting enzyme. In this study, the role of GP shedding was investigated using a reverse genetics approach by comparing recombinant viruses possessing amino acid substitutions at the GP shedding site. Virus with an L635V substitution showed a substantial decrease in shedding, whereas a D637V substitution resulted in a striking increase in the release of shed GP. Variations in shedding efficacy correlated with observed differences in the amounts of shed GP in the medium, GP present in virus-infected cells, and GP present on virions. An increase in shedding appeared to be associated with a reduction in viral cytotoxicity, and, vice versa, the virus that shed less was more cytotoxic. An increase in shedding also resulted in a reduction in viral infectivity, whereas a decrease in shedding efficacy enhanced viral growth characteristics in vitro. Differences in shedding efficacy and, as a result, differences in the amount of mature GP available for incorporation into budding virions did not equate to differences in overall release of viral particles. Likewise, data suggest that the resulting differences in the amount of mature GP on the cell surface led to variations in the GP content of released particles and, as a consequence, in infectivity. In conclusion, fine-tuning of the levels of EBOV GP expressed at the surface of virus-infected cells via GP shedding plays an important role in EBOV replication by orchestrating the balance between optimal virion GP content and cytotoxicity caused by GP. © The Author 2015. Published by Oxford University Press on behalf of the Infectious

Juxtamembrane shedding of Plasmodium falciparum AMA1 is sequence independent and essential, and helps evade invasion-inhibitory antibodies.

Directory of Open Access Journals (Sweden)

Anna Olivieri

2011-12-01

Full Text Available The malarial life cycle involves repeated rounds of intraerythrocytic replication interspersed by host cell rupture which releases merozoites that rapidly invade fresh erythrocytes. Apical membrane antigen-1 (AMA1 is a merozoite protein that plays a critical role in invasion. Antibodies against AMA1 prevent invasion and can protect against malaria in vivo, so AMA1 is of interest as a malaria vaccine candidate. AMA1 is efficiently shed from the invading parasite surface, predominantly through juxtamembrane cleavage by a membrane-bound protease called SUB2, but also by limited intramembrane cleavage. We have investigated the structural requirements for shedding of Plasmodium falciparum AMA1 (PfAMA1, and the consequences of its inhibition. Mutagenesis of the intramembrane cleavage site by targeted homologous recombination abolished intramembrane cleavage with no effect on parasite viability in vitro. Examination of PfSUB2-mediated shedding of episomally-expressed PfAMA1 revealed that the position of cleavage is determined primarily by its distance from the parasite membrane. Certain mutations at the PfSUB2 cleavage site block shedding, and parasites expressing these non-cleavable forms of PfAMA1 on a background of expression of the wild type gene invade and replicate normally in vitro. The non-cleavable PfAMA1 is also functional in invasion. However - in contrast to the intramembrane cleavage site - mutations that block PfSUB2-mediated shedding could not be stably introduced into the genomic pfama1 locus, indicating that some shedding of PfAMA1 by PfSUB2 is essential. Remarkably, parasites expressing shedding-resistant forms of PfAMA1 exhibit enhanced sensitivity to antibody-mediated inhibition of invasion. Drugs that inhibit PfSUB2 activity should block parasite replication and may also enhance the efficacy of vaccines based on AMA1 and other merozoite surface proteins.

Light aircraft sound transmission studies - Noise reduction model

Science.gov (United States)

Atwal, Mahabir S.; Heitman, Karen E.; Crocker, Malcolm J.

1987-01-01

Experimental tests conducted on the fuselage of a single-engine Piper Cherokee light aircraft suggest that the cabin interior noise can be reduced by increasing the transmission loss of the dominant sound transmission paths and/or by increasing the cabin interior sound absorption. The validity of using a simple room equation model to predict the cabin interior sound-pressure level for different fuselage and exterior sound field conditions is also presented. The room equation model is based on the sound power flow balance for the cabin space and utilizes the measured transmitted sound intensity data. The room equation model predictions were considered good enough to be used for preliminary acoustical design studies.

Modeling Phase-Aligned Gamma-Ray and Radio Millisecond Pulsar Light Curves

Science.gov (United States)

Venter, C.; Johnson, T.; Harding, A.

2012-01-01

Since the discovery of the first eight gamma-ray millisecond pulsars (MSPs) by the Fermi Large Area Telescope, this population has been steadily expanding. Four of the more recent detections, PSR J00340534, PSR J1939+2134 (B1937+21; the first MSP ever discovered), PSR J1959+2048 (B1957+20; the first discovery of a black widow system), and PSR J2214+3000, exhibit a phenomenon not present in the original discoveries: nearly phase-aligned radio and gamma-ray light curves (LCs). To account for the phase alignment, we explore models where both the radio and gamma-ray emission originate either in the outer magnetosphere near the light cylinder or near the polar caps. Using a Markov Chain Monte Carlo technique to search for best-fit model parameters, we obtain reasonable LC fits for the first three of these MSPs in the context of altitude-limited outer gap (alOG) and two-pole caustic (alTPC) geometries (for both gamma-ray and radio emission). These models differ from the standard outer gap (OG)/two-pole caustic (TPC) models in two respects: the radio emission originates in caustics at relatively high altitudes compared to the usual conal radio beams, and we allow both the minimum and maximum altitudes of the gamma-ray and radio emission regions to vary within a limited range (excluding the minimum gamma-ray altitude of the alTPC model, which is kept constant at the stellar radius, and that of the alOG model, which is set to the position-dependent null charge surface altitude). Alternatively, phase-aligned solutions also exist for emission originating near the stellar surface in a slot gap scenario (low-altitude slot gap (laSG) models). We find that the alTPC models provide slightly better LC fits than the alOG models, and both of these give better fits than the laSG models (for the limited range of parameters considered in the case of the laSG models). Thus, our fits imply that the phase-aligned LCs are likely of caustic origin, produced in the outer magnetosphere, and

Planck’s radiation law, the light quantum, and the prehistory of indistinguishability in the teaching of quantum mechanics

International Nuclear Information System (INIS)

Passon, Oliver; Grebe-Ellis, Johannes

2017-01-01

Planck’s law for black-body radiation marks the origin of quantum theory and is discussed in all introductory (or advanced) courses on this subject. However, the question whether Planck really implied quantisation is debated among historians of physics. We present a simplified account of this debate which also sheds light on the issue of indistinguishability and Einstein’s light quantum hypothesis. We suggest that the teaching of quantum mechanics could benefit from including this material beyond the question of historical accuracy. (paper)

Isoprene and monoterpene emissions in south-east Australia: comparison of a multi-layer canopy model with MEGAN and with atmospheric observations

Directory of Open Access Journals (Sweden)

K. M. Emmerson

2018-05-01

Full Text Available One of the key challenges in atmospheric chemistry is to reduce the uncertainty of biogenic volatile organic compound (BVOC emission estimates from vegetation to the atmosphere. In Australia, eucalypt trees are a primary source of biogenic emissions, but their contribution to Australian air sheds is poorly quantified. The Model of Emissions of Gases and Aerosols from Nature (MEGAN has performed poorly against Australian isoprene and monoterpene observations. Finding reasons for the MEGAN discrepancies and strengthening our understanding of biogenic emissions in this region is our focus. We compare MEGAN to the locally produced Australian Biogenic Canopy and Grass Emissions Model (ABCGEM, to identify the uncertainties associated with the emission estimates and the data requirements necessary to improve isoprene and monoterpene emissions estimates for the application of MEGAN in Australia. Previously unpublished, ABCGEM is applied as an online biogenic emissions inventory to model BVOCs in the air shed overlaying Sydney, Australia. The two models use the same meteorological inputs and chemical mechanism, but independent inputs of leaf area index (LAI, plant functional type (PFT and emission factors. We find that LAI, a proxy for leaf biomass, has a small role in spatial, temporal and inter-model biogenic emission variability, particularly in urban areas for ABCGEM. After removing LAI as the source of the differences, we found large differences in the emission activity function for monoterpenes. In MEGAN monoterpenes are partially light dependent, reducing their dependence on temperature. In ABCGEM monoterpenes are not light dependent, meaning they continue to be emitted at high rates during hot summer days, and at night. When the light dependence of monoterpenes is switched off in MEGAN, night-time emissions increase by 90–100 % improving the comparison with observations, suggesting the possibility that monoterpenes emitted from Australian

Organizational Aspects of Business Model Innovation

DEFF Research Database (Denmark)

Sund, Kristian J.; Villarroel, Juan Andrei; Bogers, Marcel

2014-01-01

shed new light on the existence of four key organizational issues: (1) organizational conflicts for scarce resources, (2) cognitive limitations in terms of a persistent dominant logic, (3) design of organizational structure, and (4) the sourcing and development of new capabilities....

Traveling waves in a continuum model of 1D schools

Science.gov (United States)

Oza, Anand; Kanso, Eva; Shelley, Michael

2017-11-01

We construct and analyze a continuum model of a 1D school of flapping swimmers. Our starting point is a delay differential equation that models the interaction between a swimmer and its upstream neighbors' wakes, which is motivated by recent experiments in the Applied Math Lab at NYU. We coarse-grain the evolution equations and derive PDEs for the swimmer density and variables describing the upstream wake. We study the equations both analytically and numerically, and find that a uniform density of swimmers destabilizes into a traveling wave. Our model makes a number of predictions about the properties of such traveling waves, and sheds light on the role of hydrodynamics in mediating the structure of swimming schools.

Shedding light on the $b\\to s$ anomalies with a dark sector

CERN Document Server

Aristizabal Sierra, D.; Vicente, Avelino

2015-01-01

The LHCb collaboration has recently reported on some anomalies in $b\\to s$ transitions. In addition to discrepancies with the Standard Model (SM) predictions in some angular observables and branching ratios, an intriguing hint for lepton universality violation was found. Here we propose a simple model that extends the SM with a dark sector charged under an additional $U(1)$ gauge symmetry. The spontaneous breaking of this symmetry gives rise to a massive $Z^\\prime$ boson, which communicates the SM particles with a valid dark matter candidate, while solving the $b\\to s$ anomalies with contributions to the relevant observables.

The Job Demands-Resources model as predictor of work identity and work engagement: A comparative analysis

OpenAIRE

Roslyn De Braine; Gert Roodt

2011-01-01

Orientation: Research shows that engaged employees experience high levels of energy and strong identification with their work, hence this study’s focus on work identity and dedication. Research purpose: This study explored possible differences in the Job Demands-Resources model (JD-R) as predictor of overall work engagement, dedication only and work-based identity, through comparative predictive analyses. Motivation for the study: This study may shed light on the dedication component o...

Electromagnetic properties of light and heavy baryons in the relativistic quark model

International Nuclear Information System (INIS)

Nicmorus Marinescu, Diana

2007-01-01

One of the main challenges of nowadays low-energy physics remains the description of the internal structure of hadrons, strongly connected to the electromagnetic properties of matter. In this vein, the success of the relativistic quark model in the analysis of the hadron structure constitutes a solid motivation for the study carried out throughout this work. The relativistic quark model is extended to the investigation of static electromagnetic properties of both heavy and light baryons. The bare contributions to the magnetic moments of the single-, double- and triple-heavy baryons are calculated. Moreover, the relativistic quark model allows the study of the electromagnetic properties of the light baryon octet incorporating meson cloud contributions in a perturbative manner. The long disputed values of the multipole ratios E2/M1 and C2/M1 and the electromagnetic form factors of the N→Δγ transition are successfully reproduced. The relativistic quark model can be viewed as a quantum field theory approach based on a phenomenological Lagrangian coupling light and heavy baryons to their constituent quarks. In our approach the baryon is a composite object of three constituent quarks, at least in leading order. The effective interaction Lagrangian is written in terms of baryon and constituent quark fields. The effective action preserves Lorentz covariance and gauge invariance. The main ingredients of the model are already introduced at the level of the interaction Lagrangian: the three-quark baryon currents, the Gaussian distribution of the constituent quarks inside the baryon and the compositeness condition which sets an upper limit for the baryon-quark vertex. The S-matrix elements are expressed by a set of Feynman quark-diagrams. The model contains only few parameters, namely, the cut-off parameter of the Gaussian quark distribution and the free quark propagator, which are unambiguously determined from the best fit to the data. The heavy quark limit within this

Electromagnetic properties of light and heavy baryons in the relativistic quark model

Energy Technology Data Exchange (ETDEWEB)

Nicmorus Marinescu, Diana

2007-06-14

One of the main challenges of nowadays low-energy physics remains the description of the internal structure of hadrons, strongly connected to the electromagnetic properties of matter. In this vein, the success of the relativistic quark model in the analysis of the hadron structure constitutes a solid motivation for the study carried out throughout this work. The relativistic quark model is extended to the investigation of static electromagnetic properties of both heavy and light baryons. The bare contributions to the magnetic moments of the single-, double- and triple-heavy baryons are calculated. Moreover, the relativistic quark model allows the study of the electromagnetic properties of the light baryon octet incorporating meson cloud contributions in a perturbative manner. The long disputed values of the multipole ratios E2/M1 and C2/M1 and the electromagnetic form factors of the N{yields}{delta}{gamma} transition are successfully reproduced. The relativistic quark model can be viewed as a quantum field theory approach based on a phenomenological Lagrangian coupling light and heavy baryons to their constituent quarks. In our approach the baryon is a composite object of three constituent quarks, at least in leading order. The effective interaction Lagrangian is written in terms of baryon and constituent quark fields. The effective action preserves Lorentz covariance and gauge invariance. The main ingredients of the model are already introduced at the level of the interaction Lagrangian: the three-quark baryon currents, the Gaussian distribution of the constituent quarks inside the baryon and the compositeness condition which sets an upper limit for the baryon-quark vertex. The S-matrix elements are expressed by a set of Feynman quark-diagrams. The model contains only few parameters, namely, the cut-off parameter of the Gaussian quark distribution and the free quark propagator, which are unambiguously determined from the best fit to the data. The heavy quark limit

C P asymmetry in Bd → φ KS: Standard model pollution

International Nuclear Information System (INIS)

Grossman, Y.; Worah, M. P.; Seattle, Univ. of Washington

1997-09-01

The difference in the time dependent C P asymmetries between the modes B → ψ K S and B d → φ K S is a clean signal for physics beyond the Standard Model. this interpretation could fail if there is a large enhancement of the matrix element of the b → u u-bar s operator between the B d initial state and the φ K S final state. They argue against this possibility and propose some experimental tests that could shed light on the situation

The SHED-IT community trial study protocol: a randomised controlled trial of weight loss programs for overweight and obese men

Directory of Open Access Journals (Sweden)

Young Myles D

2010-11-01

intake, sedentary behaviour, physical activity and dietary cognitions, sleepiness, quality of life, and perceived sexual health. Generalised linear mixed models will be used to assess all outcomes for the impact of group (Resources, Online, and Control, time (treated as categorical with levels baseline, 3-months and 6-months and the group-by-time interaction. These three terms will form the base model. 'Intention-to-treat' analysis will include all randomised participants. Discussion Our study will compare evidence-based and theoretically driven, low cost and easily disseminated strategies specifically targeting weight loss in men. The SHED-IT community trial will provide evidence to inform development and dissemination of sustainable strategies to reduce obesity in men. Trial Registration Australian New Zealand Clinical Trials Registry (ACTRN12610000699066

Thermodynamic activity-based intrinsic enzyme kinetic sheds light on enzyme-solvent interactions.

Science.gov (United States)

Grosch, Jan-Hendrik; Wagner, David; Nistelkas, Vasilios; Spieß, Antje C

2017-01-01

The reaction medium has major impact on biocatalytic reaction systems and on their economic significance. To allow for tailored medium engineering, thermodynamic phenomena, intrinsic enzyme kinetics, and enzyme-solvent interactions have to be discriminated. To this end, enzyme reaction kinetic modeling was coupled with thermodynamic calculations based on investigations of the alcohol dehydrogenase from Lactobacillus brevis (LbADH) in monophasic water/methyl tert-butyl ether (MTBE) mixtures as a model solvent. Substrate concentrations and substrate thermodynamic activities were varied separately to identify the individual thermodynamic and kinetic effects on the enzyme activity. Microkinetic parameters based on concentration and thermodynamic activity were derived to successfully identify a positive effect of MTBE on the availability of the substrate to the enzyme, but a negative effect on the enzyme performance. In conclusion, thermodynamic activity-based kinetic modeling might be a suitable tool to initially curtail the type of enzyme-solvent interactions and thus, a powerful first step to potentially understand the phenomena that occur in nonconventional media in more detail. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:96-103, 2017. © 2016 American Institute of Chemical Engineers.

Power System Stability Using Decentralized Under Frequency and Voltage Load Shedding

DEFF Research Database (Denmark)

Hoseinzadeh, Bakhtyar; Silva, Filipe Faria Da; Bak, Claus Leth

2014-01-01

information to shed the loads with higher voltage decay first. Therefore, this approach deals with coordination of voltage and frequency information instead of independent methods. Numerical simulations which are carried out in DigSilent PowerFactory software confirm the efficiency of proposed methodology...

Th17 in Animal Models of Rheumatoid Arthritis

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Motomu Hashimoto

2017-07-01

Full Text Available IL-17-secreting helper CD4 T cells (Th17 cells constitute a newly identified subset of helper CD4 T cells that play a key role in the development of rheumatoid arthritis (RA in its animal models. Recently, several models of spontaneous RA, which elucidate the mechanism of RA onset, have been discovered. These animal models shed new light on the role of Th17 in the development of autoimmune arthritis. Th17 cells coordinate inflammation and promote joint destruction, acting on various cells, including neutrophils, macrophages, synovial fibroblasts, and osteoclasts. Regulatory T cells cannot control Th17 cells under conditions of inflammation. In this review, the pathogenic role of Th17 cells in arthritis development, which was revealed by the recent animal models of RA, is discussed.

Prolonged Leptospira Urinary Shedding in a 10-Year-Old Girl

Directory of Open Access Journals (Sweden)

Emilie Chow

2012-01-01

Full Text Available We present a case of leptospirosis in a previously healthy girl following a trip to Costa Rica. While she was clinically asymptomatic, she had spirochetes cultured from her urine six weeks following her trip. Prolonged urinary shedding following infection with Leptospira is possible in humans and often has subtle manifestations in children.

Predicted congestions never occur. On the gap between transport modeling and human behavior

Directory of Open Access Journals (Sweden)

Harald FREY

2011-01-01

Full Text Available This paper presents an introduction to meso-scale transport modeling and issues of human behaviour in transport systems. Along with other examples of the human ability to learn in transport systems we look at the comparison of real life data and the prediction of modeling tools for the closure of Vienna’s inner ring road during the 2008 European Football Championship (EURO 2008. Some light is shed on the scientific question, whether currently used modeling tools are able to adequately reproduce the real-life behaviour of human beings in the transport system and should be used for transport policy decision making.

Microparticle Shedding from Neural Progenitor Cells and Vascular Compartment Cells Is Increased in Ischemic Stroke.

Science.gov (United States)

Chiva-Blanch, Gemma; Suades, Rosa; Crespo, Javier; Peña, Esther; Padró, Teresa; Jiménez-Xarrié, Elena; Martí-Fàbregas, Joan; Badimon, Lina

2016-01-01

Ischemic stroke has shown to induce platelet and endothelial microparticle shedding, but whether stroke induces microparticle shedding from additional blood and vascular compartment cells is unclear. Neural precursor cells have been shown to replace dying neurons at sites of brain injury; however, if neural precursor cell activation is associated to microparticle shedding, and whether this activation is maintained at long term and associates to stroke type and severity remains unknown. We analyzed neural precursor cells and blood and vascular compartment cells microparticle shedding after an acute ischemic stroke. Forty-four patients were included in the study within the first 48h after the onset of stroke. The cerebral lesion size was evaluated at 3-7 days of the stroke. Circulating microparticles from neural precursor cells and blood and vascular compartment cells (platelets, endothelial cells, erythrocytes, leukocytes, lymphocytes, monocytes and smooth muscle cells) were analyzed by flow cytometry at the onset of stroke and at 7 and 90 days. Forty-four age-matched high cardiovascular risk subjects without documented vascular disease were used as controls. Compared to high cardiovascular risk controls, patients showed higher number of neural precursor cell- and all blood and vascular compartment cell-derived microparticles at the onset of stroke, and after 7 and 90 days. At 90 days, neural precursor cell-derived microparticles decreased and smooth muscle cell-derived microparticles increased compared to levels at the onset of stroke, but only in those patients with the highest stroke-induced cerebral lesions. Stroke increases blood and vascular compartment cell and neural precursor cell microparticle shedding, an effect that is chronically maintained up to 90 days after the ischemic event. These results show that stroke induces a generalized blood and vascular cell activation and the initiation of neuronal cell repair process after stroke. Larger cerebral lesions

Microparticle Shedding from Neural Progenitor Cells and Vascular Compartment Cells Is Increased in Ischemic Stroke.

Directory of Open Access Journals (Sweden)

Gemma Chiva-Blanch

Full Text Available Ischemic stroke has shown to induce platelet and endothelial microparticle shedding, but whether stroke induces microparticle shedding from additional blood and vascular compartment cells is unclear. Neural precursor cells have been shown to replace dying neurons at sites of brain injury; however, if neural precursor cell activation is associated to microparticle shedding, and whether this activation is maintained at long term and associates to stroke type and severity remains unknown. We analyzed neural precursor cells and blood and vascular compartment cells microparticle shedding after an acute ischemic stroke.Forty-four patients were included in the study within the first 48h after the onset of stroke. The cerebral lesion size was evaluated at 3-7 days of the stroke. Circulating microparticles from neural precursor cells and blood and vascular compartment cells (platelets, endothelial cells, erythrocytes, leukocytes, lymphocytes, monocytes and smooth muscle cells were analyzed by flow cytometry at the onset of stroke and at 7 and 90 days. Forty-four age-matched high cardiovascular risk subjects without documented vascular disease were used as controls.Compared to high cardiovascular risk controls, patients showed higher number of neural precursor cell- and all blood and vascular compartment cell-derived microparticles at the onset of stroke, and after 7 and 90 days. At 90 days, neural precursor cell-derived microparticles decreased and smooth muscle cell-derived microparticles increased compared to levels at the onset of stroke, but only in those patients with the highest stroke-induced cerebral lesions.Stroke increases blood and vascular compartment cell and neural precursor cell microparticle shedding, an effect that is chronically maintained up to 90 days after the ischemic event. These results show that stroke induces a generalized blood and vascular cell activation and the initiation of neuronal cell repair process after stroke. Larger

A new parameterization for surface ocean light attenuation in Earth System Models: assessing the impact of light absorption by colored detrital material

Science.gov (United States)

Kim, G. E.; Pradal, M.-A.; Gnanadesikan, A.

2015-03-01

Light limitation can affect the distribution of biota and nutrients in the ocean. Light absorption by colored detrital material (CDM) was included in a fully coupled Earth System Model using a new parameterization for shortwave attenuation. Two model runs were conducted, with and without light attenuation by CDM. In a global average sense, greater light limitation associated with CDM increased surface chlorophyll, biomass and nutrients together. These changes can be attributed to the movement of biological productivity higher up the water column, which increased surface chlorophyll and biomass while simultaneously decreasing total biomass. Meanwhile, the reduction in biomass resulted in greater nutrient availability throughout the water column. Similar results were found on a regional scale in an analysis of the oceans by biome. In coastal regions, surface chlorophyll increased by 35% while total integrated phytoplankton biomass diminished by 18%. The largest relative increases in modeled surface chlorophyll and biomass in the open ocean were found in the equatorial biomes, while largest decreases in depth-integrated biomass and chlorophyll were found in the subpolar and polar biomes. This mismatch of surface and subsurface trends and their regional dependence was analyzed by comparing the competing factors of diminished light availability and increased nutrient availability on phytoplankton growth in the upper 200 m. Overall, increases in surface biomass were expected to accompany greater nutrient uptake and therefore diminish surface nutrients, but changes in light limitation decoupled trends between these two variables. Understanding changes in biological productivity requires both surface and depth-resolved information. Surface trends may be minimal or of the opposite sign to depth-integrated amounts, depending on the vertical structure of phytoplankton abundance.

Solar lanterns for domestic lighting in India. Viability of central charging station model

International Nuclear Information System (INIS)

Chaurey, A.; Kandpal, T.C.

2009-01-01

About 68 million households in India rely on kerosene as a fuel for domestic lighting. Kerosene-based lighting devices, not only for poor quality of light, but also for the risks of indoor air pollution and fire hazards, etc. are not a desired option for domestic lighting purposes. Solar lantern is a better alternative in terms of its quality of illumination, durability and versatility of use. The dissemination model for solar lantern in India has so far been based on cash sales with or without the incentive of capital subsidy. This paper analyses several dissemination models including rental and fee-for-service based on centralized solar charging station concept for CFL- and LED-based designs of solar lanterns available in India. The basis of comparison is the acceptable daily costs or rental to the user as well as to the owner of the charging station. Further, the paper studies the impact of likely escalation in kerosene price on the acceptable daily rental and estimates the amount of subsidy required to make the charging station model viable for disseminating solar lanterns among rural households. (author)

Synthetic sex pheromone attracts the leishmaniasis vector Lutzomyia longipalpis to experimental chicken sheds treated with insecticide

Directory of Open Access Journals (Sweden)

Brazil Reginaldo P

2010-03-01

Full Text Available Abstract Background Current strategies for controlling American visceral leishmaniasis (AVL have been unable to prevent the spread of the disease across Brazil. With no effective vaccine and culling of infected dogs an unpopular and unsuccessful alternative, new tools are urgently needed to manage populations of the sand fly vector, Lutzomyia longipalpis Lutz and Neiva (Diptera: Psychodidae. Here, we test two potential strategies for improving L. longipalpis control using the synthetic sand fly pheromone (±-9-methylgermacrene-B: the first in conjunction with spraying of animal houses with insecticide, the second using coloured sticky traps. Results Addition of synthetic pheromone resulted in greater numbers of male and female sand flies being caught and killed at experimental chicken sheds sprayed with insecticide, compared to pheromone-less controls. Furthermore, a ten-fold increase in the amount of sex pheromone released from test sheds increased the number of females attracted and subsequently killed. Treating sheds with insecticide alone resulted in a significant decrease in numbers of males attracted to sheds (compared to pre-spraying levels, and a near significant decrease in numbers of females. However, this effect was reversed through addition of synthetic pheromone at the time of insecticide spraying, leading to an increase in number of flies attracted post-treatment. In field trials of commercially available different coloured sticky traps, yellow traps caught more males than blue traps when placed in chicken sheds. In addition, yellow traps fitted with 10 pheromone lures caught significantly more males than pheromone-less controls. However, while female sand flies showed a preference for both blue and yellow pheromone traps sticky traps over white traps in the laboratory, neither colour caught significant numbers of females in chicken sheds, either with or without pheromone. Conclusions We conclude that synthetic pheromone could

Interaction of hematoporphyrin derivative, light, and ionizing radiation in a rat glioma model

International Nuclear Information System (INIS)

Kostron, H.; Swartz, M.R.; Miller, D.C.; Martuza, R.L.

1986-01-01

The effects of hematoporphyrin derivative, light, and cobalt 60 ( 60 Co) irradiation were studied in a rat glioma model using an in vivo and an in vitro clonogenic assay. There was no effect on tumor growth by visible light or by a single dose of 60 Co irradiation at 4 Gy or 8 Gy, whereas 16 Gy inhibited tumor growth to 40% versus the control. Hematoporphyrin derivative alone slightly stimulated growth (P less than 0.1). Light in the presence of 10 mg hematoporphyrin derivative/kg inhibited tumor growth to 32%. 60 Co irradiation in the presence of hematoporphyrin derivative produced a significant tumor growth inhibition (P less than 0.02). This growth inhibition was directly related to the concentration of hematoporphyrin derivative. The addition of 60 Co to light in the presence of hematoporphyrin derivative produced a greater growth inhibition than light or 60 Co irradiation alone. This effect was most pronounced when light was applied 30 minutes before 60 Co irradiation. Our experiments in a subcutaneous rat glioma model suggest a radiosensitizing effect of hematoporphyrin derivative. Furthermore, the photodynamic inactivation is enhanced by the addition of 60 Co irradiation. These findings may be of importance in planning new treatment modalities in malignant brain tumors

Modeling of light absorption in tissue during infrared neural stimulation

Science.gov (United States)

Thompson, Alexander C.; Wade, Scott A.; Brown, William G. A.; Stoddart, Paul R.

2012-07-01

A Monte Carlo model has been developed to simulate light transport and absorption in neural tissue during infrared neural stimulation (INS). A range of fiber core sizes and numerical apertures are compared illustrating the advantages of using simulations when designing a light delivery system. A range of wavelengths, commonly used for INS, are also compared for stimulation of nerves in the cochlea, in terms of both the energy absorbed and the change in temperature due to a laser pulse. Modeling suggests that a fiber with core diameter of 200 μm and NA=0.22 is optimal for optical stimulation in the geometry used and that temperature rises in the spiral ganglion neurons are as low as 0.1°C. The results show a need for more careful experimentation to allow different proposed mechanisms of INS to be distinguished.

Nucleon parton distributions in a light-front quark model

International Nuclear Information System (INIS)

Gutsche, Thomas; Lyubovitskij, Valery E.; Schmidt, Ivan

2017-01-01

Continuing our analysis of parton distributions in the nucleon, we extend our light-front quark model in order to obtain both the helicity-independent and the helicity-dependent parton distributions, analytically matching the results of global fits at the initial scale μ∝ 1 GeV; they also contain the correct Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution. We also calculate the transverse parton, Wigner and Husimi distributions from a unified point of view, using our light-front wave functions and expressing them in terms of the parton distributions q_v(x) and δq_v(x). Our results are very relevant for the current and future program of the COMPASS experiment at SPS (CERN). (orig.)

Nucleon parton distributions in a light-front quark model

Energy Technology Data Exchange (ETDEWEB)

Gutsche, Thomas [Universitaet Tuebingen, Institut fuer Theoretische Physik, Kepler Center for Astro and Particle Physics, Tuebingen (Germany); Lyubovitskij, Valery E. [Universitaet Tuebingen, Institut fuer Theoretische Physik, Kepler Center for Astro and Particle Physics, Tuebingen (Germany); Tomsk State University, Department of Physics, Tomsk (Russian Federation); Tomsk Polytechnic University, Laboratory of Particle Physics, Mathematical Physics Department, Tomsk (Russian Federation); Universidad Tecnica Federico Santa Maria, Departamento de Fisica y Centro Cientifico Tecnologico de Valparaiso (CCTVal), Valparaiso (Chile); Schmidt, Ivan [Universidad Tecnica Federico Santa Maria, Departamento de Fisica y Centro Cientifico Tecnologico de Valparaiso (CCTVal), Valparaiso (Chile)

2017-02-15

Continuing our analysis of parton distributions in the nucleon, we extend our light-front quark model in order to obtain both the helicity-independent and the helicity-dependent parton distributions, analytically matching the results of global fits at the initial scale μ∝ 1 GeV; they also contain the correct Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution. We also calculate the transverse parton, Wigner and Husimi distributions from a unified point of view, using our light-front wave functions and expressing them in terms of the parton distributions q{sub v}(x) and δq{sub v}(x). Our results are very relevant for the current and future program of the COMPASS experiment at SPS (CERN). (orig.)

Manipulation of light wavelength at appropriate growth stage to enhance biomass productivity and fatty acid methyl ester yield using Chlorella vulgaris.

Science.gov (United States)

Kim, Dae Geun; Lee, Changsu; Park, Seung-Moon; Choi, Yoon-E

2014-05-01

LEDs light offer several advantages over the conventional lamps, thereby being considered as the optimal light sources for microalgal cultivation. In this study, various light-emitting diodes (LEDs) especially red and blue color with different light wavelengths were employed to explore the effects of light source on phototrophic cultivation of Chlorella vulgaris. Blue light illumination led to significantly increased cell size, whereas red light resulted in small-sized cell with active divisions. Based on the discovery of the effect of light wavelengths on microalgal biology, we then applied appropriate wavelength at different growth stages; blue light was illuminated first and then shifted to red light. By doing so, biomass and lipid productivity of C. vulgaris could be significantly increased, compared to that in the control. These results will shed light on a novel approach using LED light for microalgal biotechnology. Copyright © 2014 Elsevier Ltd. All rights reserved.

Finite difference time domain modeling of light matter interaction in light-propelled microtools

DEFF Research Database (Denmark)

Bañas, Andrew Rafael; Palima, Darwin; Aabo, Thomas

2013-01-01

save time as it helps optimize the structures prior to fabrication and experiments. In addition to field distributions, optical forces can also be obtained using the Maxwell stress tensor formulation. By calculating the forces on bent waveguides subjected to tailored static light distributions, we...... may trigger highly localized non linear processes in the surface of a cell. Since these functionalities are strongly dependent on design, it is important to use models that can handle complexities and take in little simplifying assumptions about the system. Hence, we use the finite difference time...

Shedding Light on a New Treatment for Diabetic Wound Healing: A Review on Phototherapy

Directory of Open Access Journals (Sweden)

Nicolette N. Houreld

2014-01-01

Full Text Available Impaired wound healing is a common complication associated with diabetes with complex pathophysiological underlying mechanisms and often necessitates amputation. With the advancement in laser technology, irradiation of these wounds with low-intensity laser irradiation (LILI or phototherapy, has shown a vast improvement in wound healing. At the correct laser parameters, LILI has shown to increase migration, viability, and proliferation of diabetic cells in vitro; there is a stimulatory effect on the mitochondria with a resulting increase in adenosine triphosphate (ATP. In addition, LILI also has an anti-inflammatory and protective effect on these cells. In light of the ever present threat of diabetic foot ulcers, infection, and amputation, new improved therapies and the fortification of wound healing research deserves better prioritization. In this review we look at the complications associated with diabetic wound healing and the effect of laser irradiation both in vitro and in vivo in diabetic wound healing.

Identification of shed or plucked origin of Indian peafowl (Pavo cristatus) tail feathers: preliminary findings.

Science.gov (United States)

Sahajpal, Vivek; Goyal, S P

2008-06-01

Indian Peafowl (Pavo cristatus) tail covert feathers were studied to investigate the difference between shed and plucked feathers in the context of wildlife offence cases involving the killing of the Indian national bird for the purpose of plucking feathers. Plucked feathers were distinguished from shed feathers by examining their roots under low magnification of a stereoscopic microscope. A chemical test to show the presence of blood on the roots of plucked feathers was used to corroborate the plucked origin of feathers.

Light dependence of carboxylation capacity for C3 photosynthesis models

Science.gov (United States)

Photosynthesis at high light is often modelled by assuming limitation by the maximum capacity of Rubisco carboxylation at low carbon dioxide concentrations, by electron transport capacity at higher concentrations, and sometimes by triose-phosphate utilization rate at the highest concentrations. Pho...

Richards-like two species population dynamics model.

Science.gov (United States)

Ribeiro, Fabiano; Cabella, Brenno Caetano Troca; Martinez, Alexandre Souto

2014-12-01

The two-species population dynamics model is the simplest paradigm of inter- and intra-species interaction. Here, we present a generalized Lotka-Volterra model with intraspecific competition, which retrieves as particular cases, some well-known models. The generalization parameter is related to the species habitat dimensionality and their interaction range. Contrary to standard models, the species coupling parameters are general, not restricted to non-negative values. Therefore, they may represent different ecological regimes, which are derived from the asymptotic solution stability analysis and are represented in a phase diagram. In this diagram, we have identified a forbidden region in the mutualism regime, and a survival/extinction transition with dependence on initial conditions for the competition regime. Also, we shed light on two types of predation and competition: weak, if there are species coexistence, or strong, if at least one species is extinguished.

Exploring the spatial distribution of light interception and photosynthesis of canopies by means of a functional–structural plant model

Science.gov (United States)

Sarlikioti, V.; de Visser, P. H. B.; Marcelis, L. F. M.

2011-01-01

Background and Aims At present most process-based models and the majority of three-dimensional models include simplifications of plant architecture that can compromise the accuracy of light interception simulations and, accordingly, canopy photosynthesis. The aim of this paper is to analyse canopy heterogeneity of an explicitly described tomato canopy in relation to temporal dynamics of horizontal and vertical light distribution and photosynthesis under direct- and diffuse-light conditions. Methods Detailed measurements of canopy architecture, light interception and leaf photosynthesis were carried out on a tomato crop. These data were used for the development and calibration of a functional–structural tomato model. The model consisted of an architectural static virtual plant coupled with a nested radiosity model for light calculations and a leaf photosynthesis module. Different scenarios of horizontal and vertical distribution of light interception, incident light and photosynthesis were investigated under diffuse and direct light conditions. Key Results Simulated light interception showed a good correspondence to the measured values. Explicitly described leaf angles resulted in higher light interception in the middle of the plant canopy compared with fixed and ellipsoidal leaf-angle distribution models, although the total light interception remained the same. The fraction of light intercepted at a north–south orientation of rows differed from east–west orientation by 10 % on winter and 23 % on summer days. The horizontal distribution of photosynthesis differed significantly between the top, middle and lower canopy layer. Taking into account the vertical variation of leaf photosynthetic parameters in the canopy, led to approx. 8 % increase on simulated canopy photosynthesis. Conclusions Leaf angles of heterogeneous canopies should be explicitly described as they have a big impact both on light distribution and photosynthesis. Especially, the vertical

Exploring the spatial distribution of light interception and photosynthesis of canopies by means of a functional-structural plant model.

Science.gov (United States)

Sarlikioti, V; de Visser, P H B; Marcelis, L F M

2011-04-01

At present most process-based models and the majority of three-dimensional models include simplifications of plant architecture that can compromise the accuracy of light interception simulations and, accordingly, canopy photosynthesis. The aim of this paper is to analyse canopy heterogeneity of an explicitly described tomato canopy in relation to temporal dynamics of horizontal and vertical light distribution and photosynthesis under direct- and diffuse-light conditions. Detailed measurements of canopy architecture, light interception and leaf photosynthesis were carried out on a tomato crop. These data were used for the development and calibration of a functional-structural tomato model. The model consisted of an architectural static virtual plant coupled with a nested radiosity model for light calculations and a leaf photosynthesis module. Different scenarios of horizontal and vertical distribution of light interception, incident light and photosynthesis were investigated under diffuse and direct light conditions. Simulated light interception showed a good correspondence to the measured values. Explicitly described leaf angles resulted in higher light interception in the middle of the plant canopy compared with fixed and ellipsoidal leaf-angle distribution models, although the total light interception remained the same. The fraction of light intercepted at a north-south orientation of rows differed from east-west orientation by 10 % on winter and 23 % on summer days. The horizontal distribution of photosynthesis differed significantly between the top, middle and lower canopy layer. Taking into account the vertical variation of leaf photosynthetic parameters in the canopy, led to approx. 8 % increase on simulated canopy photosynthesis. Leaf angles of heterogeneous canopies should be explicitly described as they have a big impact both on light distribution and photosynthesis. Especially, the vertical variation of photosynthesis in canopy is such that the

Spatial extrapolation of light use efficiency model parameters to predict gross primary production

Directory of Open Access Journals (Sweden)

Karsten Schulz

2011-12-01

Full Text Available To capture the spatial and temporal variability of the gross primary production as a key component of the global carbon cycle, the light use efficiency modeling approach in combination with remote sensing data has shown to be well suited. Typically, the model parameters, such as the maximum light use efficiency, are either set to a universal constant or to land class dependent values stored in look-up tables. In this study, we employ the machine learning technique support vector regression to explicitly relate the model parameters of a light use efficiency model calibrated at several FLUXNET sites to site-specific characteristics obtained by meteorological measurements, ecological estimations and remote sensing data. A feature selection algorithm extracts the relevant site characteristics in a cross-validation, and leads to an individual set of characteristic attributes for each parameter. With this set of attributes, the model parameters can be estimated at sites where a parameter calibration is not possible due to the absence of eddy covariance flux measurement data. This will finally allow a spatially continuous model application. The performance of the spatial extrapolation scheme is evaluated with a cross-validation approach, which shows the methodology to be well suited to recapture the variability of gross primary production across the study sites.

Zika Virus Infection in Mice Causes Panuveitis with Shedding of Virus in Tears

Directory of Open Access Journals (Sweden)

Jonathan J. Miner

2016-09-01

Full Text Available Zika virus (ZIKV is an emerging flavivirus that causes congenital abnormalities and Guillain-Barré syndrome. ZIKV infection also results in severe eye disease characterized by optic neuritis, chorioretinal atrophy, and blindness in newborns and conjunctivitis and uveitis in adults. We evaluated ZIKV infection of the eye by using recently developed mouse models of pathogenesis. ZIKV-inoculated mice developed conjunctivitis, panuveitis, and infection of the cornea, iris, optic nerve, and ganglion and bipolar cells in the retina. This phenotype was independent of the entry receptors Axl or Mertk, given that Axl−/−, Mertk−/−, and Axl−/−Mertk−/− double knockout mice sustained levels of infection similar to those of control animals. We also detected abundant viral RNA in tears, suggesting that virus might be secreted from lacrimal glands or shed from the cornea. This model provides a foundation for studying ZIKV-induced ocular disease, defining mechanisms of viral persistence, and developing therapeutic approaches for viral infections of the eye.

Sanitation and Microbiological Quality in Production Field and Fruit-Packing Shed of Persimmon and Satsuma Mandarin in Japan

Directory of Open Access Journals (Sweden)

Hidemi Izumi

2008-01-01

Full Text Available The effects of sanitation treatments including chlorination (ca 10 ppm available chlorine of agricultural water and ethyl alcohol (70% spraying on packing shed equipment on microbial contamination on fruits and the environment were determined and compared with those in conventionally managed field and packing shed in persimmon and satsuma mandarin orchards. Chlorinated water reduced the microbial counts to levels below the lower limit of detection (1.4 log CFU/ml for bacteria and 2.0 log CFU/ml for fungi in most agricultural water samples. Microbial counts of pesticide solution, which contained the agricultural water or chlorinated water for the mixture, were lower in sanitary field than in control field in both fruit orchards. The number of bacterial and mold species detected in agricultural water, chlorinated water, and pesticide solution were almost proportional to microbial counts in each sample throughout the year. The chlorination treatment of agricultural water tended to reduce the counts of mesophiles and fungi on the peel of persimmon fruit during production season. The ethyl alcohol spray treatment on packing shed equipment resulted in a substantial microbial reduction on plastic harvest basket and container in persimmon orchard and plastic harvest basket and container, gloves, scissors, and size sorter in satsuma mandarin orchard. The spray application on packing shed equipment reduced the counts of mesophiles and fungi on the peel of persimmon fruit by >1 log CFU/g. The number of satsuma mandarin packing shed equipment containing the species found on fruit peel was higher in control than in sanitary packing shed. No human pathogens such as verotoxin-producing Escherichia coli and Salmonella were detected in any of the fruit and environmental samples. These results indicate that uses of sanitizers such as chlorine for agricultural water and ethyl alcohol for packing shed equipment would be useful in a good agricultural practices

Sanitation and Microbiological Quality in Production Field and Fruit-Packing Shed of Persimmon and Satsuma Mandarin in Japan

Directory of Open Access Journals (Sweden)

Hidemi Izumi

2008-01-01

Full Text Available The effects of sanitation treatments including chlorination (ca 10 ppm available chlorine of agricultural water and ethyl alcohol (70% spraying on packing shed equipment on microbial contamination on fruits and the environment were determined and compared with those in conventionally managed field and packing shed in persimmon and satsuma mandarin orchards. Chlorinated water reduced the microbial counts to levels below the lower limit of detection (1.4 log CFU/ml for bacteria and 2.0 log CFU/ml for fungi in most agricultural water samples. Microbial counts of pesticide solution, which contained the agricultural water or chlorinated water for the mixture, were lower in sanitary field than in control field in both fruit orchards. The number of bacterial and mold species detected in agricultural water, chlorinated water, and pesticide solution were almost proportional to microbial counts in each sample throughout the year. The chlorination treatment of agricultural water tended to reduce the counts of mesophiles and fungi on the peel of persimmon fruit during production season. The ethyl alcohol spray treatment on packing shed equipment resulted in a substantial microbial reduction on plastic harvest basket and container in persimmon orchard and plastic harvest basket and container, gloves, scissors, and size sorter in satsuma mandarin orchard. The spray application on packing shed equipment reduced the counts of mesophiles and fungi on the peel of persimmon fruit by 1 log CFU/g. The number of satsuma mandarin packing shed equipment containing the species found on fruit peel was higher in control than in sanitary packing shed. No human pathogens such as verotoxin-producing Escherichia coli and Salmonella were detected in any of the fruit and environmental samples. These results indicate that uses of sanitizers such as chlorine for agricultural water and ethyl alcohol for packing shed equipment would be useful in a good agricultural practices

A Model of the Temporal Variability of Optical Light from Extrasolar Terrestrial Planets

OpenAIRE

Ford, Eric B.; Seager, Sara; Turner, Edwin L.

2002-01-01

The light scattered by an extrasolar Earth-like planet's surface and atmosphere will vary in intensity and color as the planet rotates; the resulting light curve will contain information about the planet's properties. Since most of the light comes from a small fraction of the planet's surface, the temporal flux variability can be quite significant, $\\sim$ 10-100%. In addition, for cloudless Earth-like extrasolar planet models, qualitative changes to the surface (such as ocean fraction, ice co...

Exploring mechanisms for mobilising industrial sustainability models across different industrial locations

DEFF Research Database (Denmark)

Jacobsen, Ole Morten Noel Brings

2009-01-01

Industrial symbiosis is a model of sustainability which suggests that agglomerations of industries can achieve considerable environmental benefits by engaging in inter-organisational waste recycling, energy cascading and water recovery. This article considers how such a complex inter-organisation......Industrial symbiosis is a model of sustainability which suggests that agglomerations of industries can achieve considerable environmental benefits by engaging in inter-organisational waste recycling, energy cascading and water recovery. This article considers how such a complex inter...... symbiosis model may in this way be mobilised across industrial localities as part of the global corporate search for marked access and cost reductions. This suggestion is supported by an illustrative case study shedding some light on the mechanisms for mobilising sustainability models across localities....

Patterns of faecal nematode egg shedding after treatment of sheep with a long-acting formulation of moxidectin.

Science.gov (United States)

Crilly, James Patrick; Jennings, Amy; Sargison, Neil

2015-09-15

Much of the current information on the effects of long-acting anthelmintics on nematode populations derives either from research farms or mathematical models. A survey was performed with the aim of establishing how moxidectin is currently being used on sheep farms in the south-east of Scotland. A study was undertaken on a subsection of the surveyed farms to examine the effects of long-acting moxidectin treatments in both spring and autumn on faecal nematode egg output. The survey showed that whole flock treatments of injectable 2% moxidectin were used to control sheep scab on 21% of farms. Injectable 2% moxidectin and oral moxidectin were used to control the periparturient rise in faecal nematode egg shedding by ewes on 13% and 55% of farms respectively. The effects of injectable 2% moxidectin treatment on faecal nematode egg shedding post-treatment in both the autumn and spring were investigated by faecal nematode egg counts at the time of treatment and at 2-weekly interval thereafter on eight and six farms in the autumn and spring, respectively. Faecal egg shedding recommenced at 8 weeks (autumn) and 4 weeks (spring) post-treatment. Counts increased to a peak and then declined. The mean (95% confidence interval) peak counts post-treatment were 2.8 (0.6, 5.1), 3.6 (1.7, 5.5) and 53.5 (25.1, 82.0) eggs per gram (EPG) for autumn-treated ewes, autumn-treated lambs and spring-treated ewes respectively. The spring treated sheep showed a statistically significantly earlier return to faecal egg shedding (p=0.0125, p=0.0342) compared to both other groups, statistically significantly higher peak in egg counts than the autumn treated sheep (pegg counts (p=0.0148). There was no statistically significant difference in the timing of the peak FECs between autumn and spring (p=0.211). The FECs of all groups of sheep treated with an injectable long-acting formulation of moxidectin became positive earlier than would be expected from the period of persistence given on the datasheet

Two-singlet model for light cold dark matter

International Nuclear Information System (INIS)

Abada, Abdessamad; Ghaffor, Djamal; Nasri, Salah

2011-01-01

We extend the standard model by adding two gauge-singlet Z 2 -symmetric scalar fields that interact with visible matter only through the Higgs particle. One is a stable dark matter WIMP, and the other one undergoes a spontaneous breaking of the symmetry that opens new channels for the dark matter annihilation, hence lowering the mass of the WIMP. We study the effects of the observed dark matter relic abundance on the WIMP annihilation cross section and find that in most regions of the parameters' space, light dark matter is viable. We also compare the elastic-scattering cross section of our dark matter candidate off a nucleus with existing (CDMSII and XENON100) and projected (SuperCDMS and XENON1T) experimental exclusion bounds. We find that most of the allowed mass range for light dark matter will be probed by the projected sensitivity of the XENON1T experiment.

In-medium pion valence distributions in a light-front model

Energy Technology Data Exchange (ETDEWEB)

Melo, J.P.B.C. de, E-mail: joao.mello@cruzeirodosul.edu.br [Laboratório de Física Teórica e Computacional – LFTC, Universidade Cruzeiro do Sul, 01506-000 São Paulo (Brazil); Tsushima, K. [Laboratório de Física Teórica e Computacional – LFTC, Universidade Cruzeiro do Sul, 01506-000 São Paulo (Brazil); Ahmed, I. [Laboratório de Física Teórica e Computacional – LFTC, Universidade Cruzeiro do Sul, 01506-000 São Paulo (Brazil); National Center for Physics, Quaidi-i-Azam University Campus, Islamabad 45320 (Pakistan)

2017-03-10

Pion valence distributions in nuclear medium and vacuum are studied in a light-front constituent quark model. The in-medium input for studying the pion properties is calculated by the quark-meson coupling model. We find that the in-medium pion valence distribution, as well as the in-medium pion valence wave function, are substantially modified at normal nuclear matter density, due to the reduction in the pion decay constant.

An analytical model for light backscattering by coccoliths and coccospheres of Emiliania huxleyi.

Science.gov (United States)

Fournier, Georges; Neukermans, Griet

2017-06-26

We present an analytical model for light backscattering by coccoliths and coccolithophores of the marine calcifying phytoplankter Emiliania huxleyi. The model is based on the separation of the effects of diffraction, refraction, and reflection on scattering, a valid assumption for particle sizes typical of coccoliths and coccolithophores. Our model results match closely with results from an exact scattering code that uses complex particle geometry and our model also mimics well abrupt transitions in scattering magnitude. Finally, we apply our model to predict changes in the spectral backscattering coefficient during an Emiliania huxleyi bloom with results that closely match in situ measurements. Because our model captures the key features that control the light backscattering process, it can be generalized to coccoliths and coccolithophores of different morphologies which can be obtained from size-calibrated electron microphotographs. Matlab codes of this model are provided as supplementary material.

Epidemiology of Chronic Wasting Disease: PrPres Detection, Shedding and Environmental Contamination

National Research Council Canada - National Science Library

Lewis, Randolph V

2005-01-01

.... The specific goals of these studies are to develop sensitive assays for PrP(exp res) as a marker for infectivity, and use these techniques to monitor the dynamics and modes of shedding of PrP(exp res...

Light radiation pressure upon a wrinkled membrane – parametrization of an optically orthotropic model

Science.gov (United States)

Nerovny, N. A.; Zimin, V. N.

2018-04-01

In this paper, the problem of representing the light pressure force upon the surface of a thin wrinkled film is discussed. The common source of wrinkles is the shear deformation of the membrane sample. The optical model of such a membrane is assumed to be optically orthotropic and an analytic equation for infinitesimal light pressure force is written. A linear regression model in the case of wrinkle geometry, where a surface element can have different optical parameters, is constructed and the Bayesian approach is used to calculate the parameters of this model.

Hierarchical Models for Type Ia Supernova Light Curves in the Optical and Near Infrared

Science.gov (United States)

Mandel, Kaisey; Narayan, G.; Kirshner, R. P.

2011-01-01

I have constructed a comprehensive statistical model for Type Ia supernova optical and near infrared light curves. Since the near infrared light curves are excellent standard candles and are less sensitive to dust extinction and reddening, the combination of near infrared and optical data better constrains the host galaxy extinction and improves the precision of distance predictions to SN Ia. A hierarchical probabilistic model coherently accounts for multiple random and uncertain effects, including photometric error, intrinsic supernova light curve variations and correlations across phase and wavelength, dust extinction and reddening, peculiar velocity dispersion and distances. An improved BayeSN MCMC code is implemented for computing probabilistic inferences for individual supernovae and the SN Ia and host galaxy dust populations. I use this hierarchical model to analyze nearby Type Ia supernovae with optical and near infared data from the PAIRITEL, CfA3, and CSP samples and the literature. Using cross-validation to test the robustness of the model predictions, I find that the rms Hubble diagram scatter of predicted distance moduli is 0.11 mag for SN with optical and near infrared data versus 0.15 mag for SN with only optical data. Accounting for the dispersion expected from random peculiar velocities, the rms intrinsic prediction error is 0.08-0.10 mag for SN with both optical and near infrared light curves. I discuss results for the inferred intrinsic correlation structures of the optical-NIR SN Ia light curves and the host galaxy dust distribution captured by the hierarchical model. The continued observation and analysis of Type Ia SN in the optical and near infrared is important for improving their utility as precise and accurate cosmological distance indicators.

Effects of supplementary lighting by natural light for growth of Brassica chinensis

Science.gov (United States)

Yeh, Shih-Chuan; Lee, Hui-Ping; Kao, Shih-Tse; Lu, Ju-Lin

2016-04-01

This paper present a model of cultivated chamber with supplementary natural colour light. We investigate the effects of supplementary natural red light and natural blue light on growth of Brassica chinensis under natural white light illumination. After 4 weeks of supplementary colour light treatment, the experiment results shown that the weight of fresh leaf were not affected by supplementary natural blue light. However, those Brassica chinensis were cultivated in the chambers with supplementary natural red light obtained a significant increasing of fresh weight of leaf under both white light illuminate models. The combination of natural white light with supplementary natural red light illumination will be benefits in growth for cultivation and energy saving.

Hjemløshed i Grønland

DEFF Research Database (Denmark)

Hansen, Knud Erik; Andersen, Hans Thor

Rapporten giver en beskrivelse af karakteren af hjemløsheden i Grønland. Den beskriver forholdene for tre måder at være ude i hjemløshed på i Grønland, hvordan husstande når dertil og hvilke muligheder de har for at komme ud af hjemløsheden. I rapporten indgår beskrivelser af en række personers liv...... households get homeless and their options to get out of homelessness. The report contains descriptions of how a number of people live in homelessness. The three types are: Homeless with no fixed accommodation, resettled living in resettlement housing and homeless who are long-time living with family, friends...

Radicals excess in the retina: A model for light flashes in space

International Nuclear Information System (INIS)

Narici, L.; De Martino, A.; Brunetti, V.; Rinaldi, A.; Sannita, W.G.; Paci, M.

2009-01-01

The risk due to cosmic radiation is a major issue in planning future missions to the Moon or Mars and would be critical if inadequately addressed. Functional risks must also be considered. The perception of light flashes reported by astronauts in space, and ascribed mostly to the action of ionizing radiation in the eye (retina), is an evidence for radiation functional interaction. No detailed model of the ion/retina interaction is yet available. Here we present the first model for a generation mechanism compatible with light flashes in space, and the results of in vitro tests supporting it. The model can be a common end point for the interactions between ionizing radiation and visual system in space. It would also support the assessment of functional radiation risks in space.

Intraseasonal oscillations and their predictability in a hemispheric barotropic model with seasonal forcing

International Nuclear Information System (INIS)

Strong, C.; Jin, F.; Ghil, M.

1994-01-01

Intraseasonal oscillations with a period of 40-50 days were discovered in zonal winds over the tropical Pacific by Madden and Julian in the 1970s. Since that time, considerable modeling and observational literature on intraseasonal tropical variability has emerged. Links have been established between such fluctuations and those in global atmospheric angular momentum (AAM). This study sheds further light on the seasonal dependence of intraseasonal variability. Floquet theory is used to study the stability of the large-scale, midlatitude atmospheric system's periodic basic state

Vortex Shedding from Tapered Cylinders at high Reynolds Numbers

DEFF Research Database (Denmark)

Johansson, Jens; Andersen, Michael Styrk; Christensen, Silas Sverre

2015-01-01

percent for strakes of circular cross section. The present paper argues that this height can be reduced for structures where the critical wind velocity for vortex shedding is in the Supercritical Reynolds number regime. The present investigations are aimed for suppressing VIV on offshore wind turbine......^5 (Supercritical). Results indicate that circular strakes with a diameter corresponding to 3 percent of the structures mean diameter can be used to efficiently reduce VIV in the Supercritical Reynolds number regime....

Dynamics of virus shedding and in situ confirmation of chelonid herpesvirus 5 in Hawaiian green turtles with Fibropapillomatosis

Science.gov (United States)

Work, Thierry M.; Dagenais, Julie; Balazs, George H.; Schettle, Nelli; Ackermann, Mathias

2015-01-01

Cancers in humans and animals can be caused by viruses, but virus-induced tumors are considered to be poor sites for replication of intact virions (lytic replication). Fibropapillomatosis (FP) is a neoplastic disease associated with a herpesvirus, chelonid herpesvirus 5 (ChHV5), that affects green turtles globally. ChHV5 probably replicates in epidermal cells of tumors, because epidermal intranuclear inclusions (EIIs) contain herpesvirus-like particles. However, although EIIs are a sign of herpesvirus replication, they have not yet been firmly linked to ChHV5. Moreover, the dynamics of viral shedding in turtles are unknown, and there are no serological reagents to confirm actual presence of the specific ChHV5 virus in tissues. The investigators analyzed 381 FP tumors for the presence of EIIs and found that overall, about 35% of green turtles had lytic replication in skin tumors with 7% of tumors showing lytic replication. A few (11%) turtles accounted for more than 30% cases having lytic viral replication, and lytic replication was more likely in smaller tumors. To confirm that turtles were actively replicating ChHV5, a prerequisite for shedding, the investigators used antiserum raised against F-VP26, a predicted capsid protein of ChHV5 that localizes to the host cell nucleus during viral replication. This antiserum revealed F-VP26 in EIIs of tumors, thus confirming the presence of replicating ChHV5. In this light, it is proposed that unlike other virus-induced neoplastic diseases, FP is a disease that may depend on superspreaders, a few highly infectious individuals growing numerous small tumors permissive to viral production, for transmission of ChHV5.

Dynamics of Virus Shedding and In Situ Confirmation of Chelonid Herpesvirus 5 in Hawaiian Green Turtles With Fibropapillomatosis.

Science.gov (United States)

Work, T M; Dagenais, J; Balazs, G H; Schettle, N; Ackermann, M

2015-11-01

Cancers in humans and animals can be caused by viruses, but virus-induced tumors are considered to be poor sites for replication of intact virions (lytic replication). Fibropapillomatosis (FP) is a neoplastic disease associated with a herpesvirus, chelonid herpesvirus 5 (ChHV5), that affects green turtles globally. ChHV5 probably replicates in epidermal cells of tumors, because epidermal intranuclear inclusions (EIIs) contain herpesvirus-like particles. However, although EIIs are a sign of herpesvirus replication, they have not yet been firmly linked to ChHV5. Moreover, the dynamics of viral shedding in turtles are unknown, and there are no serological reagents to confirm actual presence of the specific ChHV5 virus in tissues. The investigators analyzed 381 FP tumors for the presence of EIIs and found that overall, about 35% of green turtles had lytic replication in skin tumors with 7% of tumors showing lytic replication. A few (11%) turtles accounted for more than 30% cases having lytic viral replication, and lytic replication was more likely in smaller tumors. To confirm that turtles were actively replicating ChHV5, a prerequisite for shedding, the investigators used antiserum raised against F-VP26, a predicted capsid protein of ChHV5 that localizes to the host cell nucleus during viral replication. This antiserum revealed F-VP26 in EIIs of tumors, thus confirming the presence of replicating ChHV5. In this light, it is proposed that unlike other virus-induced neoplastic diseases, FP is a disease that may depend on superspreaders, a few highly infectious individuals growing numerous small tumors permissive to viral production, for transmission of ChHV5. © The Author(s) 2014.

Blindness and Consciousness: new lights from the dark

DEFF Research Database (Denmark)

Pietrini, Pietro; Ptito, M.; Kupers, R.

2009-01-01

How what we perceive is transformed into a coherent and integrated representation of the world around us is a question that has fascinated humans since the early days. What happens in our brain that enables us to make sense of what we see, hear, touch, smell or taste? How does the brain of someone...... new light on how the brain works....... who has never had any visual perception form an image of the external world? Do brains from sighted and blind individuals differ and how? In this chapter we discuss recent findings from research in animals as well from functional brain imaging studies in sighted and blind individuals that are shedding...

Supernova sheds light on gamma-ray bursts

CERN Multimedia

2003-01-01

On 29 March the HETE-II satellite detected the most violent explosion in the universe to date - an enormous burst of gamma rays. Observers across the world recorded and studied the event. It appears to prove that gamma ray bursts originate in supernovae (1 page)

Snapshots to shed light on LHC performance

CERN Multimedia

2006-01-01

With the impressive size and unprecedented power of the LHC, it is all too easy to overlook the smaller devices that have the difficult task of monitoring the new accelerator. You don't have to stand too far back from the big picture to see examples of clever technology inside the LHC. One of the undulators installed in the LHC tunnel can be seen on the right of the photo. From right to left, back row: Lucio Rossi (group leader, MCS), Davide Tommasini (conceptual design, MCS), Thierry Tenaglia (integration design,TS-MME), Remo Maccaferri (project leader, MCS) and Hans Kummer (MCS/ME); front row: Gilles Trachez (MCS-ME) and Bruno Meunier (FSU-AT12). In contrast to the usual articles about the LHC's big number statistics, examples of clever problem-solving found in beam monitoring machinery show that smaller things can be beautiful too. The design of the LHC accelerator brought new challenges for monitoring the shape of the particle beam, known as the beam profile. The size of the beam shrinks as higher energi...

Clinical Trials Shed Light on Minority Health

Science.gov (United States)

... Native Hawaiian and Pacific Islander communities. OMH project manager Christine Merenda, M.P.H., R.N. explains ... are disproportionately affected by diabetes. But historically, both women and minorities have been under-represented in clinical ...

ATLAS helps shed light on the retina

CERN Multimedia

2007-01-01

Technology developed for high-energy physics has led to the discovery of a retinal cell that eluded biologists for 40 years. The 512 electrode array, inspired by silicon microstrip detector technology in ATLAS, records the electrical activity of retinal neurones.ATLAS expertise have crossed over to biology enabling the discovery of a retinal cell type that may help humans see motion. The research, carried out by ATLAS collaborators at the University of California, Santa Cruz, and by neurobiologists at the Salk Institute in La Jolla, California, appeared in the 10 October issue of the Journal of Neuroscience and may help open biologists’ eyes to the uses of techniques developed in high-energy physics. At least 22 different types of primate retinal output cell are known from anatomical studies, but the functions of only a handful of these have been determined. The cells discovered have been ca...

Expertise: to shed light on energy challenges

International Nuclear Information System (INIS)

2012-01-01

This report compares different visions of energy consumption and the associated energy production means proposed by IED (Innovation Energie Developpement), RTE and NegaWatt, and their consequences. These visions and consequences are studied in terms of demand satisfaction, share of electricity in the energy mix, power and energy needs by 2030, share of nuclear energy in electricity production, and socio-economic challenges. The studied scenarios are presented in terms of production fleet: a constant nuclear fleet, a reduced nuclear fleet, phasing out nuclear, phasing out nuclear by stopping 40 year old reactors. They are compared with respect of peak power, installed power, electricity production, electricity consumption, electricity production cost, funding requirements, annual production total cost, trade deficit, CO 2 emissions, used surface, and jobs. Other consequences of putting the electronuclear option into question again are discussed: issues of electric grids and gas networks, socio-economic consequences

Shedding new light on Gaussian harmonic analysis

NARCIS (Netherlands)

Teuwen, J.J.B.

2016-01-01

This dissertation consists out of two rather disjoint parts. One part concerns some results on Gaussian harmonic analysis and the other on an optimization problem in optics. In the first part we study the Ornstein–Uhlenbeck process with respect to the Gaussian measure. We focus on two areas. One is

Sensitivity of light interaction computer model to the absorption properties of skin

Science.gov (United States)

Karsten, A. E.; Singh, A.

2011-06-01

Light based treatments offer major benefits to patients. Many of the light based treatments or diagnostic techniques need to penetrate the skin to reach the site of interest. Human skin is a highly scattering medium and the melanin in the epidermal layer of the skin is a major absorber of light in the visible and near infrared wavelength bands. The effect of increasing absorption in the epidermis is tested on skin simulating phantoms as well as on a computer model. Changing the absorption coefficient between 0.1 mm-1 and 1.0 mm-1 resulted in a decrease of light reaching 1 mm into the sample. Transmission through a 1 mm thick sample decreased from 48% to 13% and from 31% to 2% for the different scattering coefficients.

Quantification of eDNA shedding rates from invasive bighead carp Hypophthalmichthys nobilis and silver carp Hypophthalmichthys molitrix

Science.gov (United States)

Klymus, Katy E.; Richter, Catherine A.; Chapman, Duane C.; Paukert, Craig P.

2015-01-01

Wildlife managers can more easily mitigate the effects of invasive species if action takes place before a population becomes established. Such early detection requires sensitive survey tools that can detect low numbers of individuals. Due to their high sensitivity, environmental DNA (eDNA) surveys hold promise as an early detection method for aquatic invasive species. Quantification of eDNA amounts may also provide data on species abundance and timing of an organism’s presence, allowing managers to successfully combat the spread of ecologically damaging species. To better understand the link between eDNA and an organism’s presence, it is crucial to know how eDNA is shed into the environment. Our study used quantitative PCR (qPCR) and controlled laboratory experiments to measure the amount of eDNA that two species of invasive bigheaded carps (Hypophthalmichthys nobilis and Hypophthalmichthys molitrix) shed into the water. We first measured how much eDNA a single fish sheds and the variability of these measurements. Then, in a series of manipulative lab experiments, we studied how temperature, biomass (grams of fish), and diet affect the shedding rate of eDNA by these fish. We found that eDNA amounts exhibit a positive relationship with fish biomass, and that feeding could increase the amount of eDNA shed by ten-fold, whereas water temperature did not have an effect. Our results demonstrate that quantification of eDNA may be useful for predicting carp density, as well as densities of other rare or invasive species.

Sub-saturation matter in compact stars: Nuclear modelling in the framework of the extended Thomas-Fermi theory

Energy Technology Data Exchange (ETDEWEB)

Aymard, François; Gulminelli, Francesca [CNRS and ENSICAEN, UMR6534, LPC, 14050 Caen cédex (France); Margueron, Jérôme [Institut de Physique Nucléaire de Lyon, Université Claude Bernard Lyon 1, IN2P3-CNRS, F-69622 Villeurbanne Cedex (France)

2015-02-24

A recently introduced analytical model for the nuclear density profile [1] is implemented in the Extended Thomas-Fermi (ETF) energy density functional. This allows to (i) shed a new light on the issue of the sign of surface symmetry energy in nuclear mass formulas, as well as to (ii) show the importance of the in-medium corrections to the nuclear cluster energies in thermodynamic conditions relevant for the description of core-collapse supernovae and (proto)-neutron star crust.

Modeling stock return distributions with a quantum harmonic oscillator

Science.gov (United States)

Ahn, K.; Choi, M. Y.; Dai, B.; Sohn, S.; Yang, B.

2017-11-01

We propose a quantum harmonic oscillator as a model for the market force which draws a stock return from short-run fluctuations to the long-run equilibrium. The stochastic equation governing our model is transformed into a Schrödinger equation, the solution of which features “quantized” eigenfunctions. Consequently, stock returns follow a mixed χ distribution, which describes Gaussian and non-Gaussian features. Analyzing the Financial Times Stock Exchange (FTSE) All Share Index, we demonstrate that our model outperforms traditional stochastic process models, e.g., the geometric Brownian motion and the Heston model, with smaller fitting errors and better goodness-of-fit statistics. In addition, making use of analogy, we provide an economic rationale of the physics concepts such as the eigenstate, eigenenergy, and angular frequency, which sheds light on the relationship between finance and econophysics literature.

Prolonged Shedding of Human Coronavirus in Hematopoietic Cell Transplant Recipients: Risk Factors and Viral Genome Evolution.

Science.gov (United States)

Ogimi, Chikara; Greninger, Alexander L; Waghmare, Alpana A; Kuypers, Jane M; Shean, Ryan C; Xie, Hu; Leisenring, Wendy M; Stevens-Ayers, Terry L; Jerome, Keith R; Englund, Janet A; Boeckh, Michael

2017-07-15

Recent data suggest that human coronavirus (HCoV) pneumonia is associated with significant mortality in hematopoietic cell transplant (HCT) recipients. Investigation of risk factors for prolonged shedding and intrahost genome evolution may provide critical information for development of novel therapeutics. We retrospectively reviewed HCT recipients with HCoV detected in nasal samples by polymerase chain reaction (PCR). HCoV strains were identified using strain-specific PCR. Shedding duration was defined as time between first positive and first negative sample. Logistic regression analyses were performed to evaluate factors for prolonged shedding (≥21 days). Metagenomic next-generation sequencing (mNGS) was conducted when ≥4 samples with cycle threshold values of Genome changes were consistent with the expected molecular clock of HCoV. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Very light Higgs bosons in extended models at the LHC

International Nuclear Information System (INIS)

Belyaev, Alexander; Guedes, Renato; Santos, Rui; Moretti, Stefano

2010-01-01

The Large Electron-Positron (LEP) collider experiments have constrained the mass of the standard model (SM) Higgs boson to be above 114.4 GeV. This bound applies to all extensions of the SM where the coupling of a Higgs boson to the Z boson and also the Higgs decay profile do not differ much from the SM one. However, in scenarios with extended Higgs sectors, this coupling can be made very small by a suitable choice of the parameters of the model. In such cases, the lightest CP-even Higgs boson mass can in turn be made very small. Such a very light Higgs state, with a mass of the order of the Z boson one or even smaller, could have escaped detection at LEP. In this work we perform a detailed parton level study on the feasibility of the detection of such a very light Higgs particle at the Large Hadron Collider (LHC) in the production process pp→hj→τ + τ - j, where j is a resolved jet. We conclude that there are several models where such a Higgs state could be detected at the LHC with early data.