2,248 research outputs found

    Determination of some dominant parameters of the global dynamic sea surface topography from GEOS-3 altimetry

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    The 1977 altimetry data bank is analyzed for the geometrical shape of the sea surface expressed as surface spherical harmonics after referral to the higher reference model defined by GEM 9. The resulting determination is expressed as quasi-stationary dynamic SST. Solutions are obtained from different sets of long arcs in the GEOS-3 altimeter data bank as well as from sub-sets related to the September 1975 and March 1976 equinoxes assembled with a view to minimizing seasonal effects. The results are compared with equivalent parameters obtained from the hydrostatic analysis of sporadic temperature, pressure and salinity measurements of the oceans and the known major steady state current systems with comparable wavelengths. The most clearly defined parameter (the zonal harmonic of degree 2) is obtained with an uncertainty of + or - 6 cm. The preferred numerical value is smaller than the oceanographic value due to the effect of the correction for the permanent earth tide. Similar precision is achieved for the zonal harmonic of degree 3. The precision obtained for the fourth degree zonal harmonic reflects more closely the accuracy expected from the level of noise in the orbital solutions

    Effect of daily restriction and age at initiation of a skip-a-day program for young broiler breeders.

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    Two experiments were conducted with Cobb feather sex broiler breeders comparing skip-a-day (SAD) feeding programs which began at either 2, 4, 6 or 8 wk of age. A fifth program, daily restriction started at 2 wk of age, was also compared. Chicks hatched in December and July, respectively, in Experiments 1 and 2 were exposed to natural daylight until 20 wk of age. All birds were fed ad libitum until the respective restriction programs began. All grower programs terminated at 20 wk of age. A breeder diet was given daily after 20 wk. Males and females were grown together. Sexual maturity was reached earlier in the 2-wk restriction groups (2-wi SAD in Experiment 1 and the 2-wk daily restriction in both experiments) than in the 8-wk SAD group. Egg production in Experiment 1 was also improved by the early restriction. Fertility and hatchability were not significantly affected by treatment. Based on the results of these experiments a SAD program beginning at 2 wk of age was as good as or better than one initiated at later ages. The 2-wk daily restriction program was equivalent to the 2-wk SAD program

    Lighting of end of lay broiler breeders: fluorescent versus incandescent.

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    An 18-week experiment was conducted to investigate the effects of changing from incandescent to fluorescent lighting on egg production, egg weight, fertility, and hatchability of end of lay broiler breeders housed in an open-sided house. Forty-eight-week-old Cobb feather-sexed broiler breeders were housed, 30 females and 3 males per pen, in a total of 28 pens. Incandescent lights had been used previously, so pens were randomly assigned to either fluorescent or incandescent lights giving 20 lx of light at bird level. Lights used were 60 W incandescent and 22 W fluorescent cool-white circular. Body weight and egg production were measured weekly, and fertility, hatchability, and egg weight were determined monthly from 48 to 65 weeks of age. No significant treatment effects were observed on body weight, fertility, hatchability, or egg weight. A significant reduction in egg production was observed with fluorescent lighting from Weeks 58 to 65. The reduced egg production indicated it was detrimental to change from incandescent to cool-white fluorescent lighting

    The impact of multifactorial factors on the Quality of Life of Behçet's patients over 10 years.

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    OBJECTIVE: This study analyses the 2020 survey and reviews the 2009, 2014 surveys to ascertain which Behçet's symptoms, personal and family status, patients' lifestyle, and work-related outcomes impacted on Health-Related Quality of Life (HRQoL). METHODS: Four hundred and fifty-nine Behçet's patients submitted an online survey/questionnaire. Patients provided information on socio-demographic characteristics, disease duration, historical and current symptoms, systemic and topical medication, health related lifestyle, work-related outcomes regarding employment status and claiming benefits and Quality of Life (QoL) measured by EQ-5D index. RESULTS: Four hundred and nineteen patients met the inclusion criteria, and 371 who had full data (Males: Females: Others = 84:285:2, mean-age = 41.1 ± 23.3:38 ± 13.2:40 ± 5). The main symptoms associated with patients seeking medical care were mouth ulcers 30% and genital ulcers 23%, joint 14%, and eye problems 9%. The EQ-5D index for 2009, 2014, 2020 was (mean ± SD); 0.47 ± 0.38, 0.42 ± 0.37, 0.34 ± 0.40, respectively, p < 0.05. 2020 patients had the worst values of the five domains compared to 2014 and 2009. Interestingly, mobility value was the same over the 10 years of monitoring patients. Behçet's syndrome (BS) symptoms that had significant negative impact on QoL were; 2009 (arthropathy, neurological problems, pathergy reaction, and stomach/bowel symptoms), 2014 (arthropathy, headache, neurological problems, pathergy reaction, and skin lesions), 2020 (arthropathy, neurological problems, and stomach/bowel symptoms). The 2014 and 2020 surveys reported the QoL is significantly better in patients on immunosuppressant, who did sport, continued in employment and not receiving benefits. CONCLUSION: Joints and neurological symptoms are the main symptoms which had negative impact on BS patients over the 10 years, sociodemographic (gender, age, marital, and education status), lifestyle (medication, cannabis, drinking wine, and regular exercise), employment status (employee and no career change), and accessing benefits (never claim benefit) had significant influence on patients' HRQoL

    Antiinflammatory and Immunosuppressive Activity of Sialostatin L, a Salivary Cystatin from the Tick Ixodes scapularis

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    Here we report the ability of the tick Ixodes scapularis, the main vector of Lyme disease in the United States, to actively and specifically affect the host proteolytic activity in the sites of infestation through the release of a cystatin constituent of its saliva. The cystatin presence in the saliva was verified both biochemically and immunologically. We named the protein sialostatin L because of its inhibitory action against cathepsin L. We also show that the proteases it targets, although limited in number, have a prominent role in the proteolytic cascades that take place in the extracellular and intracellular environment. As a result, sialostatin L displays an antiinflammatory role and inhibits proliferation of cytotoxic T lymphocytes. Beyond unraveling another component accounting for the properties of tick saliva, contributing to feeding success and pathogen transmission, we describe a novel tool for studying the role of papain-like proteases in diverse biologic phenomena and a protein with numerous potential pharmaceutical applications

    Insecurity for compact surfaces of positive genus

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    A pair of points in a riemannian manifold MM is secure if the geodesics between the points can be blocked by a finite number of point obstacles; otherwise the pair of points is insecure. A manifold is secure if all pairs of points in MM are secure. A manifold is insecure if there exists an insecure point pair, and totally insecure if all point pairs are insecure. Compact, flat manifolds are secure. A standing conjecture says that these are the only secure, compact riemannian manifolds. We prove this for surfaces of genus greater than zero. We also prove that a closed surface of genus greater than one with any riemannian metric and a closed surface of genus one with generic metric are totally insecure.Comment: 37 pages, 11 figure

    Scaling law in the Standard Map critical function. Interpolating hamiltonian and frequency map analysis

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    We study the behaviour of the Standard map critical function in a neighbourhood of a fixed resonance, that is the scaling law at the fixed resonance. We prove that for the fundamental resonance the scaling law is linear. We show numerical evidence that for the other resonances p/qp/q, q≄2q \geq 2, p≠0p \neq 0 and pp and qq relatively prime, the scaling law follows a power--law with exponent 1/q1/q.Comment: AMS-LaTeX2e, 29 pages with 8 figures, submitted to Nonlinearit

    4D Antarctica: a new effort aims to help bridge the gap between Antarctic crust and lithosphere structure and geothermal heat flux

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    Seismology, satellite-magnetic and aeromagnetic data, and sparse MT provide the only available geophysical proxies for large parts of Antarctica\u2019s Geothermal Heat Flux (GHF) due to the sparseness of direct measurements. However, these geophysical methods have yielded significantly different GHF estimates. This restricts our knowledge of Antarctica\u2019s contrasting tectono-thermal provinces and their influence on subglacial hydrology and ice sheet dynamics. For example, some models derived from aeromagnetic data predict remarkably high GHF in the interior of the West Antarctic Rift System (WARS), while other satellite magnetic and seismological models favour instead a significantly colder rift interior but higher GHF stretching from the Marie Byrd Land dome towards the Antarctic Peninsula, and beneath parts of the Transantarctic Mountains. Reconciling these differences in West Antarctica is imperative to better comprehend the degree to which the WARS influences the West Antarctic Ice Sheet, including thermal influences on GIA. Equally important, is quantifying geothermal heat flux variability in the generally colder but composite East Antarctic craton, especially beneath its giant marine-based basins. Here we present a new ESA project- 4D Antarctica that aims to better connect international Antarctic crust and lithosphere studies with GHF, and assess its influence on subglacial hydrology by analysing and modelling recent satellite and airborne geophysical datasets. The state of the art, hypotheses to test, and methodological approaches for five key study areas, including the Amundsen Sea Embayment, the Wilkes Subglacial Basin and the Totten catchment, the Recovery and Pensacola-Pole Basins and the Gamburtsev Sublgacial Mountains/East Antarctic Rift System are highlighted

    Limits on models of the ultrahigh energy cosmic rays based on topological defects

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    An erratum exists for this article. Please see the description link below for details.Using the propagation of ultrahigh energy nucleons, photons, and electrons in the universal radiation backgrounds, we obtain limits on the luminosity of topological defect scenarios for the origin of the highest energy cosmic rays. The limits are set as a function of the mass of the X particles emitted by the cosmic strings or other defects, the cosmological evolution of the topological defects, and the strength of the extragalactic magnetic fields. The existing data on the cosmic ray spectrum and on the isotropic 100 MeV gamma-ray background limit significantly the parameter space in which topological defects can generate the flux of the highest energy cosmic rays, and rule out models with the standard X-particle mass of 10Âč⁶GeV and higher.R. J. Protheroe and Todor Stane
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