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1.
J Zool (1987) ; 310(1): 71-82, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33911346

RESUMO

Animal movements and use of space are in part determined by interactions between individual attributes such as sex and body size and extrinsic environmental factors such as the seasonal availability, quality and spatial configuration of resource patches in the landscape. Fire is a common and widespread disturbance process that has the potential to affect animal movements through modifications to the environment. Using radiotelemetry, we examined the contribution of these factors to variation in movements and home range over a 5-year period in a forest-dwelling terrestrial turtle, Terrapene carolina, at fire-maintained and unburned habitats in the southeastern United States. Female turtles had annual home-range sizes twice as large as males and moved longer distances per day during the nesting season (June and July), but males exhibited greater spatial fidelity from year to year. Turtles at the unburned site had home-range sizes twice as large as those at the fire-maintained site, and home-range size also decreased with increasing frequency and extent of fire, but this latter effect was strongest in females. Home-range behavior was highly repeatable within individuals of both sexes over time. This is the first evidence that fire influences the spatial ecology and movements of turtles, most likely through fire's impact on the spatial configuration, availability and quality of critical resources. That individuals behaved consistently through time, but differently from one another according to both intrinsic individual attributes and extrinsic environmental factors provides strong evidence of consistent inter- and intra-population variation in space use and movement behaviors in T. carolina. Such intra-specific behavioral variation suggests applying caution when extrapolating results to other sites across the geographic range of a species for use in conservation and management.

2.
Phys Rev Lett ; 120(13): 132503, 2018 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-29694176

RESUMO

The GERDA experiment searches for the lepton-number-violating neutrinoless double-ß decay of ^{76}Ge (^{76}Ge→^{76}Se+2e^{-}) operating bare Ge diodes with an enriched ^{76}Ge fraction in liquid argon. The exposure for broad-energy germanium type (BEGe) detectors is increased threefold with respect to our previous data release. The BEGe detectors feature an excellent background suppression from the analysis of the time profile of the detector signals. In the analysis window a background level of 1.0_{-0.4}^{+0.6}×10^{-3} counts/(keV kg yr) has been achieved; if normalized to the energy resolution this is the lowest ever achieved in any 0νßß experiment. No signal is observed and a new 90% C.L. lower limit for the half-life of 8.0×10^{25} yr is placed when combining with our previous data. The expected median sensitivity assuming no signal is 5.8×10^{25} yr.

3.
Child Care Health Dev ; 44(3): 343-354, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29341191

RESUMO

BACKGROUND: Advances in medical knowledge have contributed to the increase in the number of children living with some form of long-term chronic illness or condition. As a consequence of these advancements, treatments that are more accessible and easier to administer, usually within a child's home, have been developed. However, this may mean that parents take on greater treatment responsibility and require extra time and energy to meet these tasks, additional to other responsibilities. This review paper aims to summarize and critique existing literature on working parents of children with a chronic condition, by focusing on patterns of parent work, the challenges experienced, and the flow-on consequences to well-being. METHODS: Employing a narrative, meta-synthesis of the current literature, this review identified 3 key themes related to working parents of children with chronic illness. RESULTS: The paper first identifies that although employment is less common, these parents are not necessarily nonworking. Second, these parents experience numerous challenges including balancing work and family, time constraints, stress, and feelings of "doing it all." And third, the above challenges lead to additional impacts on parental quality of life. CONCLUSIONS: This review summarizes what is currently known about work patterns, challenges, and consequences in parents of children with chronic conditions. Employment is clearly impacted for these parents. Although workplace challenges have been extensively researched, other challenges (eg, personal and family) and impacts on their well-being have not. This review discusses the present standing of this research. It outlines the strengths and limitations of the current literature, makes recommendations for future research, and suggests theoretical and practical implications of the further findings.


Assuntos
Educação Infantil/psicologia , Doença Crônica/terapia , Crianças com Deficiência/psicologia , Emprego , Poder Familiar/psicologia , Pais/psicologia , Adaptação Psicológica , Adulto , Criança , Doença Crônica/psicologia , Emprego/psicologia , Humanos , Relações Pais-Filho , Qualidade de Vida , Apoio Social , Fatores Socioeconômicos , Estresse Psicológico
4.
Phys Rev Lett ; 115(9): 091302, 2015 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-26371638

RESUMO

We have searched for periodic variations of the electronic recoil event rate in the (2-6) keV energy range recorded between February 2011 and March 2012 with the XENON100 detector, adding up to 224.6 live days in total. Following a detailed study to establish the stability of the detector and its background contributions during this run, we performed an unbinned profile likelihood analysis to identify any periodicity up to 500 days. We find a global significance of less than 1σ for all periods, suggesting no statistically significant modulation in the data. While the local significance for an annual modulation is 2.8σ, the analysis of a multiple-scatter control sample and the phase of the modulation disfavor a dark matter interpretation. The DAMA/LIBRA annual modulation interpreted as a dark matter signature with axial-vector coupling of weakly interacting massive particles to electrons is excluded at 4.8σ.

5.
Phys Rev Lett ; 111(2): 021301, 2013 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-23889382

RESUMO

We present new experimental constraints on the elastic, spin-dependent WIMP-nucleon cross section using recent data from the XENON100 experiment, operated in the Laboratori Nazionali del Gran Sasso in Italy. An analysis of 224.6 live days×34 kg of exposure acquired during 2011 and 2012 revealed no excess signal due to axial-vector WIMP interactions with 129Xe and 131Xe nuclei. This leads to the most stringent upper limits on WIMP-neutron cross sections for WIMP masses above 6 GeV/c², with a minimum cross section of 3.5×10(-40) cm² at a WIMP mass of 45 GeV/c², at 90% confidence level.

7.
Med Tr Prom Ekol ; (9): 42-4, 2013.
Artigo em Russo | MEDLINE | ID: mdl-24340774

RESUMO

The article covers individual coaching program specified by specialists in Sports Medicine and Rehabilitation Center in Bournazian FMBC of the FMBA of Russia, to improve functional durability of highly qualified athletes.


Assuntos
Desempenho Atlético , Modalidades de Fisioterapia/normas , Atletas , Desempenho Atlético/fisiologia , Desempenho Atlético/normas , Teste de Esforço/métodos , Teste de Esforço/normas , Humanos , Aptidão Física , Centros de Reabilitação/organização & administração , Federação Russa , Medicina Esportiva/métodos
8.
Phys Rev Lett ; 109(18): 181301, 2012 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-23215267

RESUMO

We report on a search for particle dark matter with the XENON100 experiment, operated at the Laboratori Nazionali del Gran Sasso for 13 months during 2011 and 2012. XENON100 features an ultralow electromagnetic background of (5.3 ± 0.6) × 10(-3) events/(keV(ee) × kg × day) in the energy region of interest. A blind analysis of 224.6 live days × 34 kg exposure has yielded no evidence for dark matter interactions. The two candidate events observed in the predefined nuclear recoil energy range of 6.6-30.5 keV(nr) are consistent with the background expectation of (1.0 ± 0.2) events. A profile likelihood analysis using a 6.6-43.3 keV(nr) energy range sets the most stringent limit on the spin-independent elastic weakly interacting massive particle-nucleon scattering cross section for weakly interacting massive particle masses above 8 GeV/c(2), with a minimum of 2 × 10(-45) cm(2) at 55 GeV/c(2) and 90% confidence level.

9.
Phys Rev Lett ; 107(13): 131302, 2011 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-22026838

RESUMO

We present results from the direct search for dark matter with the XENON100 detector, installed underground at the Laboratori Nazionali del Gran Sasso of INFN, Italy. XENON100 is a two-phase time-projection chamber with a 62 kg liquid xenon target. Interaction vertex reconstruction in three dimensions with millimeter precision allows the selection of only the innermost 48 kg as the ultralow background fiducial target. In 100.9 live days of data, acquired between January and June 2010, no evidence for dark matter is found. Three candidate events were observed in the signal region with an expected background of (1.8 ± 0.6) events. This leads to the most stringent limit on dark matter interactions today, excluding spin-independent elastic weakly interacting massive particle (WIMP) nucleon scattering cross sections above 7.0 × 10(-45) cm(2) for a WIMP mass of 50 GeV/c(2) at 90% confidence level.

10.
Phys Rev Lett ; 105(19): 193601, 2010 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-21231166

RESUMO

Atomic magnetometers have very high absolute precision and sensitivity to magnetic fields but suffer from a fundamental problem: the vectorial or tensorial interaction of light with atoms leads to "dead zones," certain orientations of the magnetic field where the magnetometer loses its sensitivity. We demonstrate a simple polarization modulation scheme that simultaneously creates coherent population trapping (CPT) in orientation and alignment, thereby eliminating dead zones. Using 87Rb in a 10 Torr buffer gas cell we measure narrow, high-contrast CPT transparency peaks for all orientations and also show the absence of systematic effects associated with nonlinear Zeeman splitting.

11.
Phys Rev Lett ; 105(13): 131302, 2010 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-21230760

RESUMO

The XENON100 experiment, in operation at the Laboratori Nazionali del Gran Sasso in Italy, is designed to search for dark matter weakly interacting massive particles (WIMPs) scattering off 62 kg of liquid xenon in an ultralow background dual-phase time projection chamber. In this Letter, we present first dark matter results from the analysis of 11.17 live days of nonblind data, acquired in October and November 2009. In the selected fiducial target of 40 kg, and within the predefined signal region, we observe no events and hence exclude spin-independent WIMP-nucleon elastic scattering cross sections above 3.4 × 10⁻44 cm² for 55 GeV/c² WIMPs at 90% confidence level. Below 20 GeV/c², this result constrains the interpretation of the CoGeNT and DAMA signals as being due to spin-independent, elastic, light mass WIMP interactions.

12.
Environ Microbiol ; 11(5): 1066-78, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19452594

RESUMO

The halophilic archaeon Halobacterium salinarum NRC-1 was used as a model system to investigate cellular damage induced by exposure to high doses of ionizing radiation (IR). Oxidative damages are the main lesions from IR and result from free radicals production via radiolysis of water. This is the first study to quantify DNA base modification in a prokaryote, revealing a direct relationship between yield of DNA lesions and IR dose. Most importantly, our data demonstrate the significance of DNA radiation damage other than strand breaks on cell survival. We also report the first in vivo evidence of reactive oxygen species scavenging by intracellular halides in H. salinarum NRC-1, resulting in increased protection against nucleotide modification and carbonylation of protein residues. Bromide ions, which are highly reactive with hydroxyl radicals, provided the greatest protection to cellular macromolecules. Modified DNA bases were repaired in 2 h post irradiation, indicating effective DNA repair systems. In addition, measurements of H. salinarum NRC-1 cell interior revealed a high Mn/Fe ratio similar to that of Deinococcus radiodurans and other radiation-resistant microorganisms, which has been shown to provide a measure of protection for proteins against oxidative damage. The work presented here supports previous studies showing that radiation resistance is the product of mechanisms for cellular protection and detoxification, as well as for the repair of oxidative damage to cellular macromolecules. The finding that not only Mn/Fe but also the presence of halides can decrease the oxidative damage to DNA and proteins emphasizes the significance of the intracellular milieu in determining microbial radiation resistance.


Assuntos
Sequestradores de Radicais Livres/farmacologia , Halobacterium salinarum/metabolismo , Halobacterium salinarum/efeitos da radiação , Radiação Ionizante , Protetores contra Radiação/farmacologia , Sais/farmacologia , Dano ao DNA , Reparo do DNA , Sequestradores de Radicais Livres/metabolismo , Halobacterium salinarum/química , Ferro/análise , Manganês/análise , Viabilidade Microbiana , Protetores contra Radiação/metabolismo , Espécies Reativas de Oxigênio/toxicidade , Sais/metabolismo
13.
Science ; 365(6460): 1445-1448, 2019 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-31488705

RESUMO

A discovery that neutrinos are Majorana fermions would have profound implications for particle physics and cosmology. The Majorana character of neutrinos would make possible the neutrinoless double-ß (0νßß) decay, a matter-creating process without the balancing emission of antimatter. The GERDA Collaboration searches for the 0νßß decay of 76Ge by operating bare germanium detectors in an active liquid argon shield. With a total exposure of 82.4 kg⋅year, we observe no signal and derive a lower half-life limit of T 1/2 > 0.9 × 1026 years (90% C.L.). Our T 1/2 sensitivity, assuming no signal, is 1.1 × 1026 years. Combining the latter with those from other 0νßß decay searches yields a sensitivity to the effective Majorana neutrino mass of 0.07 to 0.16 electron volts.

14.
J Bacteriol ; 190(15): 5210-6, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18502851

RESUMO

The genome of the halophilic archaeon Halobacterium sp. strain NRC-1 encodes homologs of the eukaryotic Mre11 and Rad50 proteins, which are involved in the recognition and end processing of DNA double-strand breaks in the homologous recombination repair pathway. We have analyzed the phenotype of Halobacterium deletion mutants lacking mre11 and/or rad50 after exposure to UV-C radiation, an alkylating agent (N-methyl-N'-nitro-N-nitrosoguanidine), and gamma radiation, none of which resulted in a decrease in survival of the mutant strains compared to that of the background strain. However, a decreased rate of repair of DNA double-strand breaks in strains lacking the mre11 gene was observed using pulsed-field gel electrophoresis. These observations led to the hypothesis that Mre11 is essential for the repair of DNA double-strand breaks in Halobacterium, whereas Rad50 is dispensable. This is the first identification of a Rad50-independent function for the Mre11 protein, and it represents a shift in the Archaea away from the eukaryotic model of homologous recombination repair of DNA double-strand breaks.


Assuntos
Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/metabolismo , Exodesoxirribonucleases/genética , Exodesoxirribonucleases/metabolismo , Halobacterium/fisiologia , Alquilantes/farmacologia , DNA Arqueal/química , Eletroforese em Gel de Campo Pulsado , Raios gama , Deleção de Genes , Halobacterium/efeitos dos fármacos , Halobacterium/enzimologia , Halobacterium/efeitos da radiação , Metilnitronitrosoguanidina/farmacocinética , Viabilidade Microbiana , Raios Ultravioleta
15.
Phys Rev E Stat Nonlin Soft Matter Phys ; 78(5 Pt 2): 056404, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19113223

RESUMO

Capillary discharge Z pinches have been shown to be efficient drivers for x-ray lasers (XRLs). In this work we examine the possibility of realizing a H_{alpha} nitrogen recombination laser ( 3-->2 transition) at lambda=13.4nm , using a capillary discharge Z pinch. A pulsed power generator with 60kA peak current and 70ns quarter period have been used to generate Z -pinch plasma in a 90-mm -long and 5-mm -diameter capillary. The plasma conditions were evaluated experimentally, using a filtered x-ray diode detector and time-integrated spectroscopy. The conditions required for the XRL were analytically estimated based on simple steady-state rate equations and then compared to experimental results. We demonstrated above 10% N7+ abundance at pinch time, while at least 50% is required. Then, in the expansion phase, the plasma is cooled in a time less than 5ns to temperatures below 60eV , as needed for the recombination laser. These results suggest that the required conditions for nitrogen-recombination lasing could be achieved in a capillary discharge Z pinch, but a higher-power driver might be needed.

16.
Sci Rep ; 7(1): 16984, 2017 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-29208997

RESUMO

Burial is generally detrimental to the preservation of biological signals. It has often been assumed that (bio)mineral-encrusted microorganisms are more resistant to burial-induced degradation than non-encrusted ones over geological timescales. For the present study, we submitted Sulfolobus acidocaldarius experimentally encrusted by amorphous Fe phosphates to constrained temperature conditions (150 °C) under pressure for 1 to 5 days, thereby simulating burial-induced processes. We document the molecular and mineralogical evolution of these assemblages down to the sub-micrometer scale using X-ray diffraction, scanning and transmission electron microscopies and synchrotron-based X-ray absorption near edge structure spectroscopy at the carbon K-edge. The present results demonstrate that the presence of Fe-phosphates enhances the chemical degradation of microbial organic matter. While Fe-phosphates remained amorphous in abiotic controls, crystalline lipscombite (FeIIxFeIII3-x(PO4)2(OH)3-x) entrapping organic matter formed in the presence of S. acidocaldarius cells. Lipscombite textures (framboidal vs. bipyramidal) appeared only controlled by the initial level of encrustation of the cells, suggesting that the initial organic matter to mineral ratio influences the competition between nucleation and crystal growth. Altogether these results highlight the important interplay between minerals and organic matter during fossilization, which should be taken into account when interpreting the fossil record.


Assuntos
Compostos Ferrosos , Fósseis , Fosfatos , Sulfolobus acidocaldarius/fisiologia , Compostos Ferrosos/química , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Minerais/química , Fosfatos/química , Sulfolobus acidocaldarius/crescimento & desenvolvimento , Sulfolobus acidocaldarius/ultraestrutura , Temperatura , Espectroscopia por Absorção de Raios X , Difração de Raios X
17.
Diagn Microbiol Infect Dis ; 25(1): 21-5, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8831041

RESUMO

The Etest was applied directly to 100 Gram-positive bacterial strains from blood cultures to measure their minimum inhibitory concentration (MIC). Results showed 100% concordance of MIC data between a direct Etest method and the standard Etest method for Streptococcus pneumoniae, beta-hemolytic streptococci, and viridans group streptococci. In addition, direct Etest for Staphylococcus aureus, coagulase negative staphylococci, Enterococcus faecium, and Enterococcus faecalis showed 83 to 100% correlation with standard Etests. These data indicate that the Etest is useful to obtain MIC data on Gram-positive cocci (especially streptococci) directly from positive blood cultures. The advantages of a direct Etest are two fold: MIC results can be obtained 24 hours earlier than standard methods and a more representative population of the bacterial isolate is tested.


Assuntos
Sangue/microbiologia , Cocos Gram-Positivos/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Antibacterianos/farmacologia , Cefotaxima/farmacologia , Cefalosporinas/farmacologia , Meios de Cultura , Eritromicina/farmacologia , Gentamicinas/farmacologia , Imipenem/farmacologia , Penicilina G/farmacologia , Penicilinas/farmacologia , Tienamicinas/farmacologia , Vancomicina/farmacologia
18.
Adv Space Res ; 34(7): 1470-6, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15846874

RESUMO

Solid-waste treatment in space for Advanced Life Support, ALS, applications requires that the material can be safely processed and stored in a confined environment. Many solid-wastes are not stable because they are wet (40-90% moisture) and contain levels of soluble organic compounds that can contribute to the growth of undesirable microorganisms with concomitant production of noxious odors. In the absence of integrated Advanced Life Support systems on orbit, permanent gas, trace volatile organic and microbiological analyses were performed on crew refuse returned from the volume F "wet" trash of three consecutive Shuttle missions (STS-105, 109, and 110). These analyses were designed to characterize the short-term biological stability of the material and assess potential crew risks resulting from microbial decay processes during storage. Waste samples were collected post-orbiter landing and sorted into packaging material, food waste, toilet waste, and bulk liquid fractions deposited during flight in the volume F container. Aerobic and anaerobic microbial loads were determined in each fraction by cultivation on R2A and by acridine orange direct count (AODC). Dry and ash weights were performed to determine both water and organic content of the materials. Experiments to determine the aerobic and anaerobic biostability of refuse stored for varying periods of time were performed by on-line monitoring of CO2 and laboratory analysis for production of hydrogen sulfide and methane. Volatile organic compounds and permanent gases were analyzed using EPA Method TO15 by USEPA et al. [EPA Method TO15, The Determination of Volatile Organic Compounds (VOCs) in Ambient Air using SUMMA, Passivated Canister Sampling and Gas Chromatographic Analysis,1999] with gas chromatography/mass spectrometry and by gas chromatography with selective detectors. These baseline measures of waste stream content, labile organics, and microbial load in the volume F Shuttle trash provide data for waste subsystem analysis and atmospheric management within the ALS Project.


Assuntos
Gases/análise , Esgotos/microbiologia , Voo Espacial , Gerenciamento de Resíduos/métodos , Ausência de Peso , Aerobiose , Anaerobiose , Dióxido de Carbono/análise , Microbiologia Ambiental , Etilenos/análise , Sulfeto de Hidrogênio/análise , Metano/análise , Oxigênio/análise , Resíduos/análise
19.
Rev Sci Instrum ; 81(7): 073303, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20687713

RESUMO

A difficult task with many particle detectors focusing on interactions below approximately 100 keV is to perform a calibration in the appropriate energy range that adequately probes all regions of the detector. Because detector response can vary greatly in various locations within the device, a spatially uniform calibration is important. We present a new method for calibration of liquid xenon (LXe) detectors, using the short-lived (83m)Kr. This source has transitions at 9.4 and 32.1 keV, and as a noble gas like Xe, it disperses uniformly in all regions of the detector. Even for low source activities, the existence of the two transitions provides a method of identifying the decays that is free of background. We find that at decreasing energies, the LXe light yield increases, while the amount of electric field quenching is diminished. Additionally, we show that if any long-lived radioactive backgrounds are introduced by this method, they will present less than 67x10(-6) events kg(-1) day(-1) keV(-1) in the next generation of LXe dark matter direct detection searches.


Assuntos
Criptônio , Xenônio/análise , Calibragem , Eletricidade , Isótopos , Modelos Lineares
20.
Phys Rev Lett ; 95(3): 030403, 2005 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-16090723

RESUMO

The coherence of a hyperfine-state superposition of a trapped 9Be+ ion in the presence of off-resonant light is studied experimentally. It is shown that Rayleigh elastic scattering of photons that does not change state populations also does not affect coherence. We observe coherence times that exceed the average scattering time of 19 photons which is determined from measured Stark shifts. This result implies that, with sufficient control over its parameters, laser light can be used to manipulate hyperfine-state superpositions with very little decoherence.

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