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1.
Phys Rev Lett ; 131(2): 021802, 2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37505961

RESUMO

This Letter reports one of the most precise measurements to date of the antineutrino spectrum from a purely ^{235}U-fueled reactor, made with the final dataset from the PROSPECT-I detector at the High Flux Isotope Reactor. By extracting information from previously unused detector segments, this analysis effectively doubles the statistics of the previous PROSPECT measurement. The reconstructed energy spectrum is unfolded into antineutrino energy and compared with both the Huber-Mueller model and a spectrum from a commercial reactor burning multiple fuel isotopes. A local excess over the model is observed in the 5-7 MeV energy region. Comparison of the PROSPECT results with those from commercial reactors provides new constraints on the origin of this excess, disfavoring at 2.0 and 3.7 standard deviations the hypotheses that antineutrinos from ^{235}U are solely responsible and noncontributors to the excess observed at commercial reactors, respectively.

2.
Phys Rev Lett ; 128(8): 081802, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35275665

RESUMO

The PROSPECT and STEREO collaborations present a combined measurement of the pure ^{235}U antineutrino spectrum, without site specific corrections or detector-dependent effects. The spectral measurements of the two highest precision experiments at research reactors are found to be compatible with χ^{2}/ndf=24.1/21, allowing a joint unfolding of the prompt energy measurements into antineutrino energy. This ν[over ¯]_{e} energy spectrum is provided to the community, and an excess of events relative to the Huber model is found in the 5-6 MeV region. When a Gaussian bump is fitted to the excess, the data-model χ^{2} value is improved, corresponding to a 2.4σ significance.

3.
BMC Psychiatry ; 21(1): 550, 2021 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-34753436

RESUMO

BACKGROUND: Suicidal ideation (SI) affects approximately 30-40% of those with major depressive disorder (MDD). To date, studies have examined the substantial humanistic and economic burden to caregivers of persons with MDD, however little is known of the impact of caring for persons with MDD when SI is present. This study examined the additional burden imposed on caregivers for persons with unipolar depression and SI in five major European countries. METHODS: A retrospective, cross-sectional analysis was conducted in five European countries using 2020 Europe National Health Wellness Survey (France, Germany, Italy, Spain and the United Kingdom) to compare differences in health and economic outcomes between caregivers of adults with unipolar depression and SI (CAUD-SI) and caregivers of adults with unipolar depression without SI (CAUD-nSI). The outcomes assessed included health-related quality of life (HRQoL; Medical Outcomes Study Short Form [SF-12v2]), health status (Short-Form 6 Dimension [SF-6D], EuroQol 5-Dimension 5-Level [EQ-5D-5L]), Work productivity and activity impairment (WPAI) and healthcare resource utilization (HRU). Linear mixed models and generalized linear mixed models adjusted for covariates were used to compare the two groups on outcomes of interest. RESULTS: Of 62,319 respondents, 0.89% (n = 554) were CAUD-SI and 1.34% (n = 837) were CAUD-nSI. In adjusted models, CAUD-SI reported greater humanistic burden than CAUD-nSI, with lower HRQoL (PCS: 42.7 vs. 45.0, p < 0.001 and MCS: 37.5 vs. 38.9, p = 0.007) and health status (SF-6D: 0.57 vs 0.60, p < 0.001 and EQ-5D-5L: 0.58 vs 0.66, p < 001). CAUD-SI respondents reported significantly higher economic burden than CAUD-nSI respondents for WPAI (percent activity impairment: 64.9% vs. 52.5%, p = 0.026) and HRU (provider visits: 10.0 vs. 7.9, p < 0.001, emergency room visits: 1.49 vs. 0.73, p < 0.001 and hospitalizations: 1.03 vs. 0.52, p < 0.001). CONCLUSION: In five European countries, caregivers of adults with depression and SI experience additional humanistic and economic burden than caregivers of adults with depression and no SI. Distinguishing caregiver groupings and their unique burden provide important insights for providing targeted support and interventions for both the patient and caregiver.


Assuntos
Transtorno Depressivo Maior , Qualidade de Vida , Adulto , Efeitos Psicossociais da Doença , Estudos Transversais , Depressão , Transtorno Depressivo Maior/terapia , Europa (Continente) , Humanos , Estudos Retrospectivos , Ideação Suicida
4.
BMC Psychiatry ; 21(1): 312, 2021 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-34154555

RESUMO

BACKGROUND: Caregiving in depression imposes a complex health and economic burden. Moreover, there is a paucity of studies examining the impact of caregiving for adult relatives with unipolar depression (CG-UD). This study assessed the burden among CG-UD in five western European (EUR5) countries (France, Germany, Italy, Spain and the United Kingdom) compared with caregivers of adults with other chronic comorbidities (CG-OD) and general non-caregiving (non-CG) population. METHODS: A retrospective observational study was conducted using the 2016 National Health and Wellness Survey (NHWS) in EUR5. Differences in humanistic burden (health status and health-related quality of life [HRQoL]) and economic burden (work productivity and activity impairments, health care resource utilization [HRU]) were assessed between CG-UD and CG-OD respondents. Caregiver-specific burden (caregiving responsibilities and caregiver reaction assessment [CRA]) was assessed between caregiver groups. Generalized linear models were used to compare between the groups on the outcomes after adjusting for potential confounders. RESULTS: Of the 77,418 survey respondents examined, 1380 identified as CG-UD, 6470 as CG-OD and 69,334 as non-CG. Compared to CG-OD and non-CG, CG-UD, reported significantly lower health status (e.g., EuroQoL-5 Dimensions-5 Levels [EQ-5D-5L]: CG-UD = 0.63, CG-OD = 0.67, and non-CG = 0.73, p < 0.001) and HRQoL (e.g., mental component score: CG-UD = 35.0, CG-OD = 37.8, and non-CG = 40.7, p < 0.001). Although effect sizes were small (d < 0.2), minimal clinically important differences (MCID) were apparent for HRQoL and health status. Increased economic-related burden was observed for work and activity impairment (e.g., absenteeism: CG-UD = 32.6%, CG-OD = 26.5%, and non-CG = 14.8%, p < 0.001) and HRU (e.g., healthcare provider [HCP; mean, past 6 months]: CG-UD = 10.5, CG-OD = 8.6, and non-CG = 6.8, p < 0.001). Caregiving-specific burden was associated with experiencing a greater lack of family support (CG-UD: 2.9 vs CG-OD: 2.8, p < 0.01), impact on finances (CG-UD: 3.0 vs CG-OD: 2.9, p = 0.036), and on the caregiver's schedule (CG-UD: 3.1 vs CG-OD: 3.0, p = 0.048). CONCLUSION: Caregivers of persons with chronic disease experience an excess humanistic and economic burden compared to the general population, with a greater burden confronting caregiver for adults with depression. These findings illustrate the far-reaching burden of depression on both the patient and the relatives who care for them.


Assuntos
Cuidadores , Qualidade de Vida , Adulto , Efeitos Psicossociais da Doença , Estudos Transversais , Depressão , França , Alemanha , Humanos , Itália , Autorrelato , Espanha , Reino Unido
5.
Phys Rev C ; 1012020.
Artigo em Inglês | MEDLINE | ID: mdl-33336123

RESUMO

Reactor neutrino experiments have seen major improvements in precision in recent years. With the experimental uncertainties becoming lower than those from theory, carefully considering all sources of ν ¯ e is important when making theoretical predictions. One source of ν ¯ e that is often neglected arises from the irradiation of the nonfuel materials in reactors. The ν ¯ e rates and energies from these sources vary widely based on the reactor type, configuration, and sampling stage during the reactor cycle and have to be carefully considered for each experiment independently. In this article, we present a formalism for selecting the possible ν ¯ e sources arising from the neutron captures on reactor and target materials. We apply this formalism to the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, the ν ¯ e source for the the Precision Reactor Oscillation and Spectrum Measurement (PROSPECT) experiment. Overall, we observe that the nonfuel ν ¯ e contributions from HFIR to PROSPECT amount to 1% above the inverse beta decay threshold with a maximum contribution of 9% in the 1.8-2.0 MeV range. Nonfuel contributions can be particularly high for research reactors like HFIR because of the choice of structural and reflector material in addition to the intentional irradiation of target material for isotope production. We show that typical commercial pressurized water reactors fueled with low-enriched uranium will have significantly smaller nonfuel ν ¯ e contribution.

6.
PLoS One ; 15(11): e0241062, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33211693

RESUMO

In 2008 the National Institutes of Health established the Research, Condition and Disease Categorization Database (RCDC) that reports the amount spent by NIH institutes for each disease. Its goal is to allow the public "to know how the NIH spends their tax dollars," but it has been little used. The RCDC for 2018 was used to assess 428 schizophrenia-related research projects funded by the National Institute of Mental Health. Three senior psychiatrists independently rated each on its likelihood ("likely", "possible", "very unlikely") of improving the symptoms and/or quality of life for individuals with schizophrenia within 20 years. At least one reviewer rated 386 (90%), and all three reviewers rated 302 (71%), of the research projects as very unlikely to provide clinical improvement within 20 years. Reviewer agreement for the "very unlikely" category was good; for the "possible" category was intermediate; and for the "likely" category was poor. At least one reviewer rated 30 (7%) of the research projects as likely to provide clinical improvement within 20 years. The cost of the 30 projects was 5.5% of the total NIMH schizophrenia-related portfolio or 0.6% of the total NIMH budget. Study results confirm previous 2016 criticisms that the NIMH schizophrenia-related research portfolio disproportionately underfunds clinical research that might help people currently affected. Although the results are preliminary, since the RCDC database has not previously been used in this manner and because of the subjective nature of the assessment, the database would appear to be a useful tool for disease advocates who wish to ascertain how NIH spends its public funds.


Assuntos
Pesquisa Biomédica/economia , National Institute of Mental Health (U.S.)/economia , Esquizofrenia/economia , Bases de Dados Factuais , Humanos , Estados Unidos
7.
Med Vet Entomol ; 34(3): 302-308, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32175623

RESUMO

Bartonella sp. infection is quite common in free-roaming dogs in many tropical countries. However, limited information is available of the presence of these pathogens in Mexico. The present study looked at prevalence of Bartonella exposure and/or infection in dogs and their fleas in Central Mexico. Blood samples were collected from 31 stray dogs in August 2014 at the municipal pound, Tulancingo, Mexico, as well as fleas on 26 of them. Bartonella seropositivity was 46.9%, including 35.5% for Bartonella henselae, 45% for Bartonella clarridgeiae and 32.2% for Bartonella vinsonii subsp. berkhoffii. Three (9.7%) dogs were polymerase chain reaction (PCR) positive for the Bartonella gltA gene. Partial sequencing of that gene revealed that these three dogs were infected with B. henselae. In total, 86 fleas were collected from 26 dogs (range 1-9 fleas per dog), including 52 Ctenocephalides felis and 34 Ctenocephalides canis. Of 40 pools of fleas (20 pools of C. canis and 20 pools of C. felis), five (12.5%) were PCR positive for the Bartonella sp. gltA gene, including three C. canis pools (five fleas) and two C. felis pools (three fleas). All sequences showed 99.25% to 100% homology with B. henselae Houston I.


Assuntos
Infecções por Bartonella/veterinária , Bartonella henselae/isolamento & purificação , Bartonella/isolamento & purificação , Doenças do Cão/epidemiologia , Sifonápteros/microbiologia , Animais , Infecções por Bartonella/epidemiologia , Infecções por Bartonella/microbiologia , Doenças do Cão/microbiologia , Cães , Feminino , Masculino , México/epidemiologia , Reação em Cadeia da Polimerase/veterinária , Prevalência
8.
J Vet Cardiol ; 27: 1-9, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31830708

RESUMO

OBJECTIVES: Bartonella infection has been associated with endocarditis in humans, dogs, cats and cattle. In order to evaluate the importance of this pathogen as a possible source of endocarditis in United States military working dogs (MWDs), we performed a retrospective case-control study on 26 dogs with histological diagnosis of culture negative endocarditis (n = 18), endomyocarditis (n = 5) or endocardiosis (n = 3) and 28 control dogs without any histological cardiac lesions. METHODS: DNA was extracted from paraffin embedded cardiac valves and tissues from case and control dogs and submitted to PCR testing with primers targeting the Bartonella gltA gene. PCR-RFLP using four restriction endonucleases and partial sequencing was then performed to determine the Bartonella species involved. RESULTS: Nineteen (73%) cases were PCR positive for Bartonella, including B. henselae (8 dogs), B. vinsonii subsp. berkhoffii (6 dogs), B. washoensis (2 dogs) and B. elizabethae (1 dog). Only one control dog was weakly PCR positive for Bartonella. Based on the type of histological diagnosis, 13 (72.2%) dogs with endocarditis, 3 (60%) dogs with endomyocarditis and all 3 dogs with endocardiosis were Bartonella PCR positive. CONCLUSIONS: Bartonella sp. Infections were correlated with cardiopathies in US military working dogs. Systemic use of insecticides against ectoparasites and regular testing of MWDs for Bartonella infection seem highly appropriate to prevent such life-threatening exposures.


Assuntos
Infecções por Bartonella/veterinária , Bartonella/isolamento & purificação , Doenças do Cão/epidemiologia , Endocardite/veterinária , Animais , Bartonella/classificação , Bartonella/genética , Infecções por Bartonella/epidemiologia , Estudos de Casos e Controles , DNA Bacteriano , Doenças do Cão/microbiologia , Cães , Endocardite/microbiologia , Feminino , Masculino , Miocardite/microbiologia , Miocardite/veterinária , Reação em Cadeia da Polimerase/veterinária , Prevalência , Estudos Retrospectivos , Estados Unidos
9.
Phys Rev Lett ; 122(25): 251801, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31347897

RESUMO

This Letter reports the first measurement of the ^{235}U ν[over ¯]_{e} energy spectrum by PROSPECT, the Precision Reactor Oscillation and Spectrum experiment, operating 7.9 m from the 85 MW_{th} highly enriched uranium (HEU) High Flux Isotope Reactor. With a surface-based, segmented detector, PROSPECT has observed 31678±304(stat) ν[over ¯]_{e}-induced inverse beta decays, the largest sample from HEU fission to date, 99% of which are attributed to ^{235}U. Despite broad agreement, comparison of the Huber ^{235}U model to the measured spectrum produces a χ^{2}/ndf=51.4/31, driven primarily by deviations in two localized energy regions. The measured ^{235}U spectrum shape is consistent with a deviation relative to prediction equal in size to that observed at low-enriched uranium power reactors in the ν[over ¯]_{e} energy region of 5-7 MeV.

10.
Phys Rev Lett ; 121(25): 251802, 2018 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-30608854

RESUMO

This Letter reports the first scientific results from the observation of antineutrinos emitted by fission products of ^{235}U at the High Flux Isotope Reactor. PROSPECT, the Precision Reactor Oscillation and Spectrum Experiment, consists of a segmented 4 ton ^{6}Li-doped liquid scintillator detector covering a baseline range of 7-9 m from the reactor and operating under less than 1 m water equivalent overburden. Data collected during 33 live days of reactor operation at a nominal power of 85 MW yield a detection of 25 461±283 (stat) inverse beta decays. Observation of reactor antineutrinos can be achieved in PROSPECT at 5σ statistical significance within 2 h of on-surface reactor-on data taking. A reactor model independent analysis of the inverse beta decay prompt energy spectrum as a function of baseline constrains significant portions of the previously allowed sterile neutrino oscillation parameter space at 95% confidence level and disfavors the best fit of the reactor antineutrino anomaly at 2.2σ confidence level.

11.
Pediatr Blood Cancer ; 62(2): 285-290, 2015 02.
Artigo em Inglês | MEDLINE | ID: mdl-25359689

RESUMO

BACKGROUND: Although the use of central venous catheters (CVCs) has greatly improved the quality of care of children with cancer, these catheters increase the risk of deep vein thrombosis (DVT) and the potential long-term complication of post-thrombotic syndrome (PTS). We aimed to study PTS post-CVC removal using physical, functional and health related quality of life (HRQoL) domains in childhood cancer and bone marrow transplantation (BMT) survivors. PROCEDURE: We conducted a prospective study in a cohort of childhood cancer and BMT survivors post-CVC use. Participants were evaluated for PTS with the Modified Villalta Score (MVS) and the Manco-Johnson Instrument (MJI). HRQoL was assessed using the PedsQL™ questionnaire. RESULTS: A total of 158 children were enrolled at a median of 41 (4-149) months from CVC removal. Signs and symptoms of PTS were present in 34% (95% confidence interval [CI] 27-43%) (MVS criteria) and 30.5% (95% CI 23.1-37.8%) (MJI criteria). Diagnosis of PTS was associated with history of CVC occlusion, history of CVC-related DVT and the use of ≥2 CVCs. The presence of signs and symptoms of PTS was a predictor for low HRQoL tested by the PedsQL™ Total Scale scores and Physical Health Summary scores. CONCLUSIONS: PTS post-CVC removal in pediatric cancer survivors is not a rare event. The association between PTS and the history of CVC occlusion confirms earlier findings, and suggests that CVC occlusion may indicate asymptomatic DVT. PTS is also associated with lower HRQoL scores highlighting the need to study preventive measures, especially for high risk groups. Pediatr Blood Cancer 2015;62:285-290. © 2014 Wiley Periodicals, Inc.


Assuntos
Antineoplásicos/administração & dosagem , Cateterismo Venoso Central/efeitos adversos , Cateteres Venosos Centrais/efeitos adversos , Neoplasias/tratamento farmacológico , Síndrome Pós-Trombótica/diagnóstico , Adolescente , Adulto , Antineoplásicos/uso terapêutico , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos Prospectivos , Fatores de Risco , Inquéritos e Questionários , Adulto Jovem
12.
J Environ Manage ; 129: 333-40, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-23978621

RESUMO

Elevated particulate matter concentrations due to Asian long-range transport (LRT) are frequently observed in the free troposphere (FT) above the Pacific Northwest, U.S. Transport of this aerosol from the FT to the boundary layer (BL) and its effect to local air quality remain poorly constrained. We used data collected at the Mount Bachelor observatory (MBO, 2.8 km a.s.l) and from ground stations in the Pacific Northwest to study transport of fine particulate matter (PM) from the FT to the BL. During Asian LRT episodes PM concentrations were clearly elevated above the corresponding monthly averages at MBO as well as at low elevation sites across Washington and Oregon. Also, a clear correlation between MBO and low elevation sites was observed, indicating that LRT episodes are seen in both the FT and BL. In addition, drum impactor measurements show that the chemical composition of PM at MBO was similar to that measured at the BL sites. Using a simple regression model, we estimate that during springtime, when the transport from Asia is most effective, the contribution of Asian sources to PM2.5 in clean background areas of the Pacific Northwest was on average 1.7 µg m(-3) (representing approximately 50-80% of PM). The influence of LRT PM was also seen in measurement stations situated in the urban and urban background areas. However, the fraction of LRT PM was less pronounced (36-50% of PM) due to larger local emissions in the urban areas.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Material Particulado/análise , Ásia , Monitoramento Ambiental , Modelos Teóricos , Nefelometria e Turbidimetria , Oregon , Tamanho da Partícula , Washington
13.
Phys Rev Lett ; 110(17): 171801, 2013 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-23679706

RESUMO

We report on ν(e) and ν(e) appearance in ν(µ) and ν(µ) beams using the full MINOS data sample. The comparison of these ν(e) and ν(e) appearance data at a 735 km baseline with θ13 measurements by reactor experiments probes δ, the θ23 octant degeneracy, and the mass hierarchy. This analysis is the first use of this technique and includes the first accelerator long-baseline search for ν(µ) → ν(e). Our data disfavor 31% (5%) of the three-parameter space defined by δ, the octant of the θ23, and the mass hierarchy at the 68% (90%) C.L. We measure a value of 2sin(2)(2θ13)sin(2)(θ23) that is consistent with reactor experiments.

14.
Environ Sci Technol ; 47(13): 7277-84, 2013 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-23441676

RESUMO

The Reno Atmospheric Mercury Intercomparison Experiment (RAMIX) was in Reno, NV from August 22, 2011 to September 16, 2011. The goals of the experiment were to compare existing and new methods for measurements of ambient elemental and oxidized Hg, and to test these with quantitative spikes of Hg(0), HgBr2, O3 and water vapor. In this paper we describe the design, testing, and deployment of a high flow manifold system designed to deliver ambient air and spiked compounds to multiple instruments simultaneously. The manifold was constructed of 1" OD PFA tubing and heated to 115 °C for the entire active zone. Manifold flow was controlled at ∼200 LPM using a blower and a velocity sensor in a feedback control system. Permeation tubes in controlled ovens were used to deliver Hg(0) and HgBr2. Ozone was generated from a small UV lamp in a flow of high purity O2. Water vapor was generated by pumping a flow of purified N2 through heated, high purity water. The spiking delivery for Hg(0), HgBr2, O3, and water vapor after dilution in the manifold ranged up to 20 ng m(-3), 0.64 ng m(-3), 100 ppbv, and 20 g kg(-1), respectively. During laboratory tests the average transmission efficiencies for Hg(0), HgBr2, and O3 were found to be 92%, 76%, and 93%, respectively.


Assuntos
Poluentes Atmosféricos/análise , Brometos/análise , Monitoramento Ambiental/instrumentação , Compostos de Mercúrio/análise , Mercúrio/análise , Monitoramento Ambiental/métodos , Desenho de Equipamento , Nevada , Oxirredução , Ozônio/análise , Água/análise
15.
Phys Rev Lett ; 108(19): 191801, 2012 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-23003026

RESUMO

We report an improved measurement of ν(µ) disappearance over a distance of 735 km using the MINOS detectors and the Fermilab Main Injector neutrino beam in a ν(µ)-enhanced configuration. From a total exposure of 2.95×10(20) protons on target, of which 42% have not been previously analyzed, we make the most precise measurement of Δm2=[2.62(-0.28)(+0.31)(stat)±0.09(syst)]×10(-3) eV2 and constrain the ν(µ) mixing angle sin2(2θ)>0.75 (90% C.L.). These values are in agreement with Δm2 and sin2(2θ) measured for ν(µ), removing the tension reported in [P. Adamson et al. (MINOS), Phys. Rev. Lett. 107, 021801 (2011).].

16.
Phys Rev Lett ; 107(18): 181802, 2011 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-22107623

RESUMO

We report the results of a search for ν(e) appearance in a ν(µ) beam in the MINOS long-baseline neutrino experiment. With an improved analysis and an increased exposure of 8.2 × 10(20) protons on the NuMI target at Fermilab, we find that 2 sin(2) (θ(23))sin(2)(2θ(13))<0.12(0.20) at 90% confidence level for δ = 0 and the normal (inverted) neutrino mass hierarchy, with a best-fit of 2sin(2) (θ(23))sin(2)(2θ(13)) = 0.041(-0.031)(+0.047) (0.079(-0.053) (+0.071)). The θ(13) = 0 hypothesis is disfavored by the MINOS data at the 89% confidence level.

17.
Neuroscience ; 192: 205-18, 2011 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-21723921

RESUMO

The BK channel is a Ca(2+) and voltage-gated conductance responsible for shaping action potential waveforms in many types of neurons. Type II BK channels are differentiated from type I channels by their pharmacology and slow gating kinetics. The ß4 accessory subunit confers type II properties on BK α subunits. Empirically derived properties of BK channels, with and without the ß4 accessory subunit, were obtained using a heterologous expression system under physiological ionic conditions. These data were then used to study how BK channels alone (type I) and with the accessory ß4 subunit (type II) modulate action potential properties in biophysical neuron models. Overall, the models support the hypothesis that it is the slower kinetics provided by the ß4 subunit that endows the BK channel with type II properties, which leads to broadening of action potentials and, secondarily, to greater recruitment of SK channels reducing neuronal excitability. Two regions of parameter space distinguished type II and type I effects; one where the range of BK-activating Ca(2+) was high (>20 µM) and the other where BK-activating Ca(2+) was low (∼0.4-1.2 µM). The latter required an elevated BK channel density, possibly beyond a likely physiological range. BK-mediated sharpening of the spike waveform associated with the lack of the ß4 subunit was sensitive to the properties of voltage-gated Ca(2+) channels due to electrogenic effects on spike duration. We also found that depending on Ca(2+) dynamics, type II BK channels may have the ability to contribute to the medium AHP, a property not generally ascribed to BK channels, influencing the frequency-current relationship. Finally, we show how the broadening of action potentials conferred by type II BK channels can also indirectly increase the recruitment of SK-type channels decreasing the excitability of the neuron.


Assuntos
Potenciais de Ação/fisiologia , Canais de Potássio Ativados por Cálcio de Condutância Alta/fisiologia , Modelos Neurológicos , Animais , Simulação por Computador , Células HEK293 , Humanos , Ativação do Canal Iônico/fisiologia , Camundongos , Técnicas de Patch-Clamp
18.
J Environ Radioact ; 102(11): 1032-8, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21719167

RESUMO

We report results of air monitoring started due to the recent natural catastrophe on 11 March 2011 in Japan and the severe ensuing damage to the Fukushima Dai-ichi nuclear reactor complex. On 17-18 March 2011, we registered the first arrival of the airborne fission products (131)I, (132)I, (132)Te, (134)Cs, and (137)Cs in Seattle, WA, USA, by identifying their characteristic gamma rays using a germanium detector. We measured the evolution of the activities over a period of 23 days at the end of which the activities had mostly fallen below our detection limit. The highest detected activity from radionuclides attached to particulate matter amounted to 4.4 ± 1.3 mBq m(-3) of (131)I on 19-20 March.


Assuntos
Poluentes Radioativos do Ar/análise , Monitoramento Ambiental/métodos , Cinza Radioativa/análise , Liberação Nociva de Radioativos , Radioisótopos/análise , Cidades , Humanos , Japão , Medição de Risco/métodos , Fatores de Tempo , Washington
19.
Phys Rev Lett ; 107(1): 011802, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21797535

RESUMO

Results are reported from a search for active to sterile neutrino oscillations in the MINOS long-baseline experiment, based on the observation of neutral-current neutrino interactions, from an exposure to the NuMI neutrino beam of 7.07×10(20) protons on target. A total of 802 neutral-current event candidates is observed in the Far Detector, compared to an expected number of 754 ± 28(stat) ± 37(syst) for oscillations among three active flavors. The fraction f(s) of disappearing ν(µ) that may transition to ν(s) is found to be less than 22% at the 90% C.L.

20.
Phys Rev Lett ; 107(2): 021801, 2011 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-21797594

RESUMO

This Letter reports the first direct observation of muon antineutrino disappearance. The MINOS experiment has taken data with an accelerator beam optimized for ν(µ) production, accumulating an exposure of 1.71 × 10²° protons on target. In the Far Detector, 97 charged current ν(µ) events are observed. The no-oscillation hypothesis predicts 156 events and is excluded at 6.3σ. The best fit to oscillation yields |Δm²| = [3.36(-0.40)(+0.46)(stat) ± 0.06(syst)] × 10⁻³ eV², sin²(2θ) = 0.86(-0.12)(+0.11)(stat) ± 0.01(syst). The MINOS ν(µ) and ν(µ) measurements are consistent at the 2.0% confidence level, assuming identical underlying oscillation parameters.

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