618 resultados para Deb Rollins
Resumo:
This paper reports on an unmodeled, all-sky search for gravitational waves from merging intermediate mass black hole binaries (IMBHB). The search was performed on data from the second joint science run of the LIGO and Virgo detectors (July 2009-October 2010) and was sensitive to IMBHBs with a range up to similar to 200 Mpc, averaged over the possible sky positions and inclinations of the binaries with respect to the line of sight. No significant candidate was found. Upper limits on the coalescence-rate density of nonspinning IMBHBs with total masses between 100 and 450 M-circle dot and mass ratios between 0.25 and 1 were placed by combining this analysis with an analogous search performed on data from the first LIGO-Virgo joint science run (November 2005-October 2007). The most stringent limit was set for systems consisting of two 88 M-circle dot black holes and is equal to 0.12 Mpc(-3) Myr(-1) at the 90% confidence level. This paper also presents the first estimate, for the case of an unmodeled analysis, of the impact on the search range of IMBHB spin configurations: the visible volume for IMBHBs with nonspinning components is roughly doubled for a population of IMBHBs with spins aligned with the binary's orbital angular momentum and uniformly distributed in the dimensionless spin parameter up to 0.8, whereas an analogous population with antialigned spins decreases the visible volume by similar to 20%.
Resumo:
We present the first results of an all-sky search for continuous gravitational waves from unknown spinning neutron stars in binary systems using LIGO and Virgo data. Using a specially developed analysis program, the TwoSpect algorithm, the search was carried out on data from the sixth LIGO science run and the second and third Virgo science runs. The search covers a range of frequencies from 20 Hz to 520 Hz, a range of orbital periods from 2 to similar to 2,254 h and a frequency-and period-dependent range of frequency modulation depths from 0.277 to 100 mHz. This corresponds to a range of projected semimajor axes of the orbit from similar to 0.6 x 10(-3) ls to similar to 6,500 ls assuming the orbit of the binary is circular. While no plausible candidate gravitational wave events survive the pipeline, upper limits are set on the analyzed data. The most sensitive 95% confidence upper limit obtained on gravitational wave strain is 2.3 x 10(-24) at 217 Hz, assuming the source waves are circularly polarized. Although this search has been optimized for circular binary orbits, the upper limits obtained remain valid for orbital eccentricities as large as 0.9. In addition, upper limits are placed on continuous gravitational wave emission from the low-mass x-ray binary Scorpius X-1 between 20 Hz and 57.25 Hz.
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We report the results of a multimessenger search for coincident signals from the LIGO and Virgo gravitational-wave observatories and the partially completed IceCube high-energy neutrino detector, including periods of joint operation between 2007-2010. These include parts of the 2005-2007 run and the 2009-2010 run for LIGO-Virgo, and IceCube's observation periods with 22, 59 and 79 strings. We find no significant coincident events, and use the search results to derive upper limits on the rate of joint sources for a range of source emission parameters. For the optimistic assumption of gravitational-wave emission energy of 10(-2) M(circle dot)c(2) at similar to 150 Hz with similar to 60 ms duration, and high-energy neutrino emission of 1051 erg comparable to the isotropic gamma-ray energy of gamma-ray bursts, we limit the source rate below 1.6 x 10(-2) Mpc(-3) yr(-1). We also examine how combining information from gravitational waves and neutrinos will aid discovery in the advanced gravitational-wave detector era.
Resumo:
Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of Omega(GW)(f) = Omega(alpha)(f/f(ref))(alpha), we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5-1726 Hz. In the frequency band of 41.5-169.25 Hz for a spectral index of alpha = 0, we constrain the energy density of the stochastic background to be Omega(GW)(f) < 5.6 x 10(-6). For the 600-1000 Hz band, Omega(GW)(f) < 0.14(f/900 Hz)(3), a factor of 2.5 lower than the best previously reported upper limits. We find Omega(GW)(f) < 1.8 x 10(-4) using a spectral index of zero for 170-600 Hz and Omega(GW)(f) < 1.0(f/1300 Hz)(3) for 1000-1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves.
Resumo:
In this paper we present the results of a coherent narrow-band search for continuous gravitational-wave signals from the Crab and Vela pulsars conducted on Virgo VSR4 data. In order to take into account a possible small mismatch between the gravitational-wave frequency and two times the star rotation frequency, inferred from measurement of the electromagnetic pulse rate, a range of 0.02 Hz around two times the star rotational frequency has been searched for both the pulsars. No evidence for a signal has been found and 95% confidence level upper limits have been computed assuming both that polarization parameters are completely unknown and that they are known with some uncertainty, as derived from x-ray observations of the pulsar wind torii. For Vela the upper limits are comparable to the spin-down limit, computed assuming that all the observed spin-down is due to the emission of gravitational waves. For Crab the upper limits are about a factor of 2 below the spin-down limit, and represent a significant improvement with respect to past analysis. This is the first time the spin-down limit is significantly overcome in a narrow-band search.
Resumo:
We present results of a search for continuously emitted gravitational radiation, directed at the brightest low-mass x-ray binary, Scorpius X-1. Our semicoherent analysis covers 10 days of LIGO S5 data ranging from 50-550 Hz, and performs an incoherent sum of coherent F-statistic power distributed amongst frequency-modulated orbital sidebands. All candidates not removed at the veto stage were found to be consistent with noise at a 1% false alarm rate. We present Bayesian 95% confidence upper limits on gravitational-wave strain amplitude using two different prior distributions: a standard one, with no a priori assumptions about the orientation of Scorpius X-1; and an angle-restricted one, using a prior derived from electromagnetic observations. Median strain upper limits of 1.3 x 10(-24) and 8 x 10(-25) are reported at 150 Hz for the standard and angle-restricted searches respectively. This proof-of-principle analysis was limited to a short observation time by unknown effects of accretion on the intrinsic spin frequency of the neutron star, but improves upon previous upper limits by factors of similar to 1.4 for the standard, and 2.3 for the angle-restricted search at the sensitive region of the detector.
Resumo:
The Advanced LIGO gravitational wave detectors are second-generation instruments designed and built for the two LIGO observatories in Hanford, WA and Livingston, LA, USA. The two instruments are identical in design, and are specialized versions of a Michelson interferometer with 4 km long arms. As in Initial LIGO, Fabry-Perot cavities are used in the arms to increase the interaction time with a gravitational wave, and power recycling is used to increase the effective laser power. Signal recycling has been added in Advanced LIGO to improve the frequency response. In the most sensitive frequency region around 100 Hz, the design strain sensitivity is a factor of 10 better than Initial LIGO. In addition, the low frequency end of the sensitivity band is moved from 40 Hz down to 10 Hz. All interferometer components have been replaced with improved technologies to achieve this sensitivity gain. Much better seismic isolation and test mass suspensions are responsible for the gains at lower frequencies. Higher laser power, larger test masses and improved mirror coatings lead to the improved sensitivity at mid and high frequencies. Data collecting runs with these new instruments are planned to begin in mid-2015.
Resumo:
The literature reports dealing with the dietary electrolyte ratio (K+Cl)/ Na are rare, although the concept has been proposed by Mongin in 1981. Thus, its application appears to be limited as a nutritional strategy in feed formulation, which usually meets only the minimum nutritional recommendations in Na, K and Cl. The objective of this study was to evaluate the performance of broilers submitted to different dietary electrolyte balances (DEB) Na+K-Cl and dietary electrolyte ratio (DER) from 1 to 21 d of age. A total of 1575 male 1-d old broiler chicks were randomly assigned to 5 treatments with 9 replicates of 35 chicks each. The treatments consisted of diets with 5 relation of electrolytes, arising from combinations DEB/DER 150/3, 250/2, 250/3, 250/4 and 350/3, with use of NaCl, NaHCO3, KCl, K2SO4 and CaCl2. All diets were corn-soybean meal based and formulated to meet or exceed the NRC (1994) requirements. Chicks had ad libitum access to feed and water in floor pens with wood shavings as litter. Body weight, feed intake and feed conversion ratio were measured at 21 d of age. It was found that only the feed conversion was significantly affected (P = 0.0142) by the combinations of relation of electrolytes (DEB and DER). The supplementation levels in DEB and DER were made to fit the data into a surface analysis to allow increasing levels of DEB (150–350 mEq/kg) and narrow and broad ratio of DER (2–4). For the canonical analysis of response surface was obtained the stationary point for body weight (DEB = 255.77 mEq/kg, and DER = 2.73:1) the value was 942.02 g; for feed intake (DEB = 251.69 mEq / kg and DER = 3.51:1), the value was 1200.02 g; and for feed conversion (DEB = 254.62 mEq/kg and DER = 3.06:1) the value was 1.35. The results of this experiment indicated that the best performance was obtained with combinations of relation of electrolytes for DEB between 251 and 255 mEq/kg and DER between 2.73:1 and 3.5:1.
Resumo:
An experiment was conducted to evaluate the impact in relation of dietary electrolytes, based on changes in the balance Na+K-Cl (DEB) and the ratio (K+Cl)/Na (DER) on the performance and survival of broilers subjected to acute heat stress. A total of 1575 male broiler chicks from 1 to 46 d of age were allocated in a 5x3 factorial arrangement in a completely randomized design, totaling of 15 treatments with 3 replicates of 35 birds each. The treatments consisted of 5 diets with electrolyte balances, arising from combinations DEB/DER (150/3, 250/2, 250/3, 250/4 and 350/3), associated with different times of application or not of the acute heat stress on birds at 25 and 36 d old. All diets were cornsoybean meal based and formulated to meet or exceed NRC requirements. Chicks had ad libitum access to feed and water in floor pens with wood shavings as litter. It was possible to verify that a DEB of 250 mEq/kg and a DER very close to the 3:1 providing a more nutritionally adequate diet. There was, however, the impossibility of obtaining a more suitable electrolyte ratio for a very low DEB (150 mEq/kg) or very high (350 mEq/kg) and also, to a very narrow DER (2:1) or very wide (4:1), due to an unfavorable performance and survival rate of birds in these conditions electrolytes adjustments of K, Na and Cl. There was clear indication, with significant difference (P < 0.05), that the DER has the potential to improve the performance of broilers, since simultaneous adjustment made in DEB, even in conditions of acute stress. The results of performance and survival rate of this study also indicate clearly that DER could not replace the DEB, and vice versa, in practical diets for broilers. Therefore, it can be affirmed that the strategic formulation of the correct electrolyte balance for DEB and DER enhances the performance and is able to prevent the effect of heat stress in broiler chickens, leading to better performance and survival.
Resumo:
The objective of this study was to evaluate the application of early age thermal conditioning (TC) and dietary electrolyte balances (DEB) to minimize the effect of heat stress. A total of 240 Cobb 500 1-d-old male broiler chicks was randomly allocated to 24 floor pens with six replicates per treatment in a 2x2 factorial arrangement (with and without TC and with and without DEB). Dietary treatments consisted: (T1) a traditional diet without TC; (T2) traditional diet with TC; (T3) with the application of dietary electrolyte and without TC and (T4) application of dietary electrolyte with TC. The thermal conditioning was conducted at 5 d of age (36°C for 24 h), only half of the batch (120 birds). After this period, all birds were transferred to boxes of 1.5 x 3m (10 birds / box), with wood shavings reused as litter. Chicks were exposed to chronic heat stress (32°C) for 6 h from 35 to 39 d of age, in all treatments, being electronically monitored the temperature and humidity of the microclimate of the birds. Feed and water were provided ad libitum, even during periods of stress. Were measured performance data (weight gain, feed intake and feed conversion) and mortality rate. Data were subjected to ANOVA using the GLM procedures of SAS. The results of this study demonstrated no interaction effects of all evaluated parameters (performance and mortality). Therefore, no synergism occurred when both strategies (TC and DEB) were applied. Only the first week there was prejudice on broiler performance with the application of the TC and apparently the technique of early age thermal conditioning no improve the resistance of broilers to chronic heat stress. On the other hand, DEB had significantly favorable effects (P<0.05) on performance and minimized mortality immediately after application of the TC.
Resumo:
In this action research study I focused on my eighth grade pre-algebra students’ abilities to attack problems with enthusiasm and self confidence whether they completely understand the concepts or not. I wanted to teach them specific strategies and introduce and use precise vocabulary as a part of the problem solving process in hopes that I would see students’ confidence improve as they worked with mathematics. I used non-routine problems and concept-related open-ended problems to teach and model problem solving strategies. I introduced and practiced communication with specific and precise vocabulary with the goal of increasing student confidence and lowering student anxiety when they were faced with mathematics problem solving. I discovered that although students were working more willingly on problem solving and more inclined to attempt word problems using the strategies introduced in class, they were still reluctant to use specific vocabulary as they communicated to solve problems. As a result of this research, my style of teaching problem solving will evolve so that I focus more specifically on strategies and use precise vocabulary. I will spend more time introducing strategies and necessary vocabulary at the beginning of the year and continue to focus on strategies and process in order to lower my students’ anxiety and thus increase their self confidence when it comes to doing mathematics, especially problem solving.
Resumo:
Research, Cooperation Pays Off for Fish Farmers -- Peter Butchko, District Supervisor, USDA-APHIS-WS, Mississippi and NADCA Vice-President, East Thoughts... Robert H. Giles, Jr., President, NADCA Book Review : The Wildlife Damage Inspection Handbook, by Stephen Vantassel with Tom Olander; Reviewed by Rex E. Marsh British Fox Hunting Ban Fails Passage Recent Coyote Research From Texas: Diets of Coyotes (Canis latrans) in the Edwards Plateau and Trans-Pecos regions of Texas, by J. Harris Glass, S.K. Canon, and D. Rollins Long-time NADCA Member Robert H. Schmidt Featured in Associated Press Article on Nuisance Animal Control Industry Research Continues in New Zealand and Australia on the Efficacy of Rabbit Calicivirus Disease as Rabbit Population Control Method Latest Rabies Trends Subject of Meeting of State and National Health Experts: Keeping Physicians and the Public Informed on Managing Deadly Disease Bogus Gizmos and Gadgets No Help With Homeowners' Wildlife Problems
Resumo:
Supporting children's curiosity was considered important at my family child care home. How could we best achieve this? As my assistant caregiver Deb and 1 attended professional development workshops, we began to wonder if the project approach (Helm & Katz 2001) would be an effective means of supporting inquiry and collaborative learning. Before we would commit ourselves, we wanted to learn more. We had many questions. Just what is the project approach? What does it look like? How will it support children's learning? What do we need to be successful with it? The literature suggested many examples of successful projects at child care centers and preschools (Breig-Allen et al. 1998; Harkem: 1999; Beneke 2000; Glassman & Whaley 2000). Our challenge was how to adapt the project approach to our home child care situations.
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NADCA Election in Progress Berryman Institute Announces 1999 Awards New Probe Editor to be Appointed: Larry Sullivan Ken Garner Retires Book Review: "Master Land Snaring: Canine and Coon Techniques, Effective in All Terrains." by Newt Sterling as told to Bob Noonan. 1999. 58 pages, illustrated. NPCA Gets New Name Lobster Plates: PETA (People for the Ethical Treatment of Animals) is fighting to prevent the return of the lobster to Maine's automobile license plates. Active Antis in the Northwest Animal Rights Violence on Increase Abstracts from the 6th Annual Conference of The Wildlife Society: Monitoring of Sin Nombre Hantavirus in deer mice of the Southwest, USA -- Robinson, Rhonda /., Kathryn D. Bennett, James R. Biggs, Timothy K. Haarmann, David C. Keller, and Mary E. Salisbury Predators in the classroom: A prickly paradigm for educators -- Rollins, Dale Trends in bat rabies in the U.S.: Shaping public health policy -- Rupprecht, Charles E., Sharon B. Messenger, and Jean S. Smith
Resumo:
Black carbon (BC) is an important fraction of many soils worldwide and plays an important role in global C biogeochemistry. However, few studies have examined how it influences the mineralization of added organic matter (AOM) and its incorporation into soil physical fractions and whether BC decomposition is increased by AOM. BC-rich Anthrosols and BC-poor adjacent soils from the Central Amazon (Brazil) were incubated for 532 days either with or without addition of (13)C-isotopically different plant residue. Total C mineralization from the BC-rich Anthrosols with AOM was 25.5% (P < 0.05) lower than with mineralization from the BC-poor adjacent soils. The AOM contributed to a significantly (P < 0.05) higher proportion to the total C mineralized in the BC-rich Anthrosols (91-92%) than the BC-poor adjacent soils (69-80%). The AOM was incorporated more rapidly in BC-rich than BC-poor soils from the separated free light fraction through the intra-aggregate light fraction into the stable organo-mineral fraction and up to 340% more AOM was found in the organo-mineral fraction. This more rapid stabilization was observed despite a significantly (P < 0.05) lower metabolic quotient for BC-rich Anthrosols. The microbial biomass (MB) was up to 125% greater (P < 0.05) in BC-rich Anthrosols than BC-poor adjacent soils. To account for increased MB adsorption onto BC during fumigation extraction, a correction factor was developed via addition of a (13)C-enriched microbial culture. The recovery was found to be 21-41 % lower (P < 0.05) for BC-rich than BC-poor soils due to re-adsorption of MB onto BC. Mineralization of native soil C was enhanced to a significantly greater degree in BC-poor adjacent soils compared to BC-rich Anthrosols as a result of AOM. No positive priming by way of cometabolism due to AOM could be found for aged BC in the soils. (C) 2009 Elsevier Ltd. All rights reserved.