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1.
Public Health ; 222: 54-59, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37523949

RESUMO

OBJECTIVE: This study evaluates the impact of England's COVID-19 shielding programme on mortality in the City of Liverpool in North West England. STUDY DESIGN: Shielded and non-shielded people are compared using data from linked routine health records on all people registered with a general practitioner in Liverpool from April 2020 to June 2021. METHODS: A discrete time hazard model and interactions between the shielding status and the periods of higher risk of transmission are used to explore the effects of shielding across the major phases of the COVID-19 pandemic. RESULTS: Shielding was associated with a 34% reduction in the risk of dying (HR = 0.66, 95% CI: 0.58 to 0.76) compared with a propensity-matched non-shielded group. Shielding appeared to reduce mortality during the first and third waves, but not during the second wave, where shielding was not mandated by the government. The effects were similar for males and females, but more protective for those living in the least deprived areas of Liverpool. CONCLUSIONS: It is likely that the shielding programme in Liverpool saved lives, although this seems to have been a little less effective in more deprived areas. A comprehensive programme for identifying vulnerable groups and providing them with advice and support is likely to be important for future respiratory virus pandemics. Additional support may be necessary for socio-economically disadvantaged groups to avoid increased inequalities.


Assuntos
COVID-19 , Masculino , Feminino , Humanos , COVID-19/prevenção & controle , Pandemias , Inglaterra/epidemiologia , Cidades , Projetos de Pesquisa
2.
Public Health ; 218: 128-135, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37019028

RESUMO

OBJECTIVES: The pandemic has compounded existing inequalities. In the UK, there have been calls for a new cross-government health inequalities strategy. This study aims to evaluate the effectiveness of national governmental efforts between 1997 and 2010, referred to as the National Health Inequalities Strategy (NHIS). STUDY DESIGN: population-based observational study. METHODS: Using Global Burden of Disease data, age-standardised years of life lost due to premature mortality (YLL) rates per 10,000 were extracted for 150 Upper Tier Local Authority (UTLA) regions in England for every year between 1990 and 2019. The slope index of inequality was calculated using YLL rates for all causes, individual conditions, and risk factors. Joinpoint regression was used to assess the trends of any changes which arose before, during or after the NHIS. RESULTS: Absolute inequalities in YLL rates for all causes remained stable between 1990 and 2000, before decreasing over the following 10 years. After 2010, improvements slowed. A similar trend can be observed amongst inequalities in YLLs for individual causes, including ischaemic heart disease, stroke, breast cancer and lung cancer amongst females, and ischaemic heart disease stroke, diabetes and self-harm amongst males. This trend was also observed amongst certain risk factors, notably blood pressure, cholesterol, tobacco and dietary risks. Inequalities were generally greater in males than in females; however, trends were similar across both sexes. The NHIS coincided with significant reductions in inequalities in YLLs due to ischaemic heart disease and lung cancer. CONCLUSIONS: The findings suggest that the NHIS coincided with a reduction in health inequalities in England. Policy makers should consider a new cross-government strategy to tackle health inequalities drawing from the success of the previous NHIS.


Assuntos
Neoplasias Pulmonares , Isquemia Miocárdica , Acidente Vascular Cerebral , Masculino , Feminino , Humanos , Causas de Morte , Expectativa de Vida , Inglaterra/epidemiologia
3.
Epidemiol Infect ; 147: e215, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-31364538

RESUMO

Shiga toxin-producing Escherichia coli (STEC) infection can cause serious illness including haemolytic uraemic syndrome. The role of socio-economic status (SES) in differential clinical presentation and exposure to potential risk factors amongst STEC cases has not previously been reported in England. We conducted an observational study using a dataset of all STEC cases identified in England, 2010-2015. Odds ratios for clinical characteristics of cases and foodborne, waterborne and environmental risk factors were estimated using logistic regression, stratified by SES, adjusting for baseline demographic factors. Incidence was higher in the highest SES group compared to the lowest (RR 1.54, 95% CI 1.19-2.00). Odds of Accident and Emergency attendance (OR 1.35, 95% CI 1.10-1.75) and hospitalisation (OR 1.71, 95% CI 1.36-2.15) because of illness were higher in the most disadvantaged compared to the least, suggesting potential lower ascertainment of milder cases or delayed care-seeking behaviour in disadvantaged groups. Advantaged individuals were significantly more likely to report salad/fruit/vegetable/herb consumption (OR 1.59, 95% CI 1.16-2.17), non-UK or UK travel (OR 1.76, 95% CI 1.40-2.27; OR 1.85, 95% CI 1.35-2.56) and environmental exposures (walking in a paddock, OR 1.82, 95% CI 1.22-2.70; soil contact, OR 1.52, 95% CI 2.13-1.09) suggesting other unmeasured risks, such as person-to-person transmission, could be more important in the most disadvantaged group.


Assuntos
Infecções por Escherichia coli/epidemiologia , Disparidades nos Níveis de Saúde , Síndrome Hemolítico-Urêmica/epidemiologia , Toxina Shiga/efeitos adversos , Escherichia coli Shiga Toxigênica/isolamento & purificação , Adulto , Análise de Variância , Bases de Dados Factuais , Diarreia/epidemiologia , Diarreia/microbiologia , Escherichia coli Êntero-Hemorrágica/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Feminino , Síndrome Hemolítico-Urêmica/microbiologia , Humanos , Incidência , Masculino , Análise Multivariada , Avaliação das Necessidades , Prevalência , Estudos Retrospectivos , Medição de Risco , Classe Social , Reino Unido/epidemiologia
4.
J Public Health (Oxf) ; 41(1): 3-9, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29444304

RESUMO

BACKGROUND: Greater regional devolution can reduce economic inequalities between regions; however, the impact on health inequalities is not clear. We investigated the association between changes over time in the level of devolution in European countries and regional economic and health inequalities. METHODS: We used the proportion of government expenditure controlled by subnational levels of government as our measure of devolution in 14 European countries between 1995 and 2011. Fixed effects linear regression models were used to analyse trends in the level of devolution, trends in regional economic inequalities (Gini-coefficient) and trends in regional health inequalities (slope index) in life expectancy. RESULTS: Each additional percentage of government expenditure managed at subnational level reduced the Gini-coefficient of regional GDP by -0.17 points (95% CI: -0.33 to -0.01; P = 0.04). However, it increased the slope index of regional life expectancy by 23 days (95% CI: -2 to 48; P = 0.07). When trends in regional economic inequalities were controlled for, as a potential mediator-increased devolution-was significantly associated with an increase in health inequalities between regions (P = 0.01). CONCLUSIONS: Increased devolution does not appear to reduce regional health inequalities-even when it reduces regional economic inequalities-and it could be associated with increased health inequalities.


Assuntos
Financiamento Governamental/economia , Disparidades nos Níveis de Saúde , Disparidades em Assistência à Saúde/economia , Europa (Continente) , Humanos , Expectativa de Vida , Modelos Lineares , Fatores Socioeconômicos
5.
J Public Health (Oxf) ; 41(2): 214-221, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29762730

RESUMO

OBJECTIVE: Investigating the extent to which providing children with free swimming access during school holidays increased participation in swimming and whether this effect differed according to the socioeconomic deprivation of the neighbourhoods in which children lived. SETTING: A highly disadvantaged local authority (LA) in North West England. INTERVENTION: Provision of children with free swimming during the summer holidays. OUTCOME MEASURES: Number of children swimming, and the number of swims, per 100 population in 2014. DESIGN: Comparative regression discontinuity investigating the extent to which participation rates amongst children aged 5-15 were greater in the intervention LA compared to a similar control LA. We estimated the differential effect of the intervention across five groups, defined by quintiles of area deprivation. RESULTS: Free swimming during the summer holidays was associated with an additional 6% of children swimming (95% CI: 4-9%) and an additional 33 swims per 100 children per year (95% CI: 21-44). The effects were greatest in areas with intermediate levels of deprivation (quintiles 3 and 4) within this deprived LA. CONCLUSION: Providing free facilities for children in disadvantaged areas is likely to increase swimming participation and may help reduce inequalities in physical activity.


Assuntos
Piscinas , Natação/estatística & dados numéricos , Adolescente , Criança , Pré-Escolar , Inglaterra , Feminino , Humanos , Masculino , Fatores Socioeconômicos , Piscinas/estatística & dados numéricos , Populações Vulneráveis/estatística & dados numéricos
6.
J Public Health (Oxf) ; 41(4): 652-664, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-30346563

RESUMO

BACKGROUND: The Equal North network was developed to take forward the implications of the Due North report of the Independent Inquiry into Health Equity. The aim of this exercise was to identify how to reduce health inequalities in the north of England. METHODS: Workshops (15 groups) and a Delphi survey (3 rounds, 368 members) were used to consult expert opinion and achieve consensus. Round 1 answered open questions around priorities for action; Round 2 used a 5-point Likert scale to rate items; Round 3 responses were re-rated alongside a median response to each item. In total, 10 workshops were conducted after the Delphi survey to triangulate the data. RESULTS: In Round 1, responses from 253 participants generated 39 items used in Round 2 (rated by 144 participants). Results from Round 3 (76 participants) indicate that poverty/implications of austerity (4.87 m, IQR 0) remained the priority issue, with long-term unemployment (4.8 m, IQR 0) and mental health (4.7 m, IQR 1) second and third priorities. Workshop 3 did not diverge from findings in Round 1. CONCLUSIONS: Practice professionals and academics agreed that reducing health inequalities in the North of England requires prioritizing research that tackles structural determinants concerning poverty, the implications of austerity measures and unemployment.


Assuntos
Política de Saúde , Prioridades em Saúde , Disparidades nos Níveis de Saúde , Técnica Delphi , Educação , Inglaterra/epidemiologia , Indicadores Básicos de Saúde , Humanos , Determinantes Sociais da Saúde
7.
Health Promot Int ; 34(3): 379-388, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29240917

RESUMO

Reducing or eliminating the cost to the public of using leisure facilities is one tool that local authorities have available to reduce inequalities in physical activity (PA). There is limited evidence about the effect of leisure entrance charges and their impact on participation. This study aimed to ascertain how facility pricing influenced the decisions people made about how to pay and what to pay for and how, in turn, these decisions impacted on participation for different groups. A total of 83 members of the public living in 4 local authorities in the North West of England were involved in focus groups or individual interviews. The results show that cost was a key factor which influenced PA participation in low income neighbourhoods. In practise, however, the majority of service users navigated the range of prices or payment options to find one that was suitable rather than simply reporting whether leisure was affordable or not. Whilst pre-paid options (e.g. direct debit memberships) encouraged participation, entrance charges incurred each time an individual participated had a negative impact on frequency but were a convenient way of paying for occasional use or for people who were unable to afford a pre-paid option. Free access also helped people who could not afford pre-paid membership to exercise regularly as well as incentivizing non-users to try activities. The research concluded that policies that include components of free access and offer more flexible payment options are most likely to contribute to reducing inequalities in PA.


Assuntos
Custos e Análise de Custo/economia , Exercício Físico , Academias de Ginástica/economia , Promoção da Saúde/economia , Adulto , Idoso , Inglaterra , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Desemprego
8.
Bull World Health Organ ; 96(4): 256-265, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29695882

RESUMO

OBJECTIVE: To estimate the use and outcomes of the Malawian programme for the prevention of mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV). METHODS: In a cross-sectional analysis of 33 744 mother-infant pairs, we estimated the weighted proportions of mothers who had received antenatal HIV testing and/or maternal antiretroviral therapy and infants who had received nevirapine prophylaxis and/or HIV testing. We calculated the ratios of MTCT at 4-26 weeks postpartum for subgroups that had missed none or at least one of these four steps. FINDINGS: The estimated uptake of antenatal testing was 97.8%; while maternal antiretroviral therapy was 96.3%; infant prophylaxis was 92.3%; and infant HIV testing was 53.2%. Estimated ratios of MTCT were 4.7% overall and 7.7% for the pairs that had missed maternal antiretroviral therapy, 10.7% for missing both maternal antiretroviral therapy and infant prophylaxis and 11.4% for missing maternal antiretroviral therapy, infant prophylaxis and infant testing. Women younger than 19 years were more likely to have missed HIV testing (adjusted odds ratio, aOR: 4.9; 95% confidence interval, CI: 2.3-10.6) and infant prophylaxis (aOR: 6.9; 95% CI: 1.2-38.9) than older women. Women who had never started maternal antiretroviral therapy were more likely to have missed infant prophylaxis (aOR: 15.4; 95% CI: 7.2-32.9) and infant testing (aOR: 13.7; 95% CI: 4.2-83.3) than women who had. CONCLUSION: Most women used the Malawian programme for the prevention of MTCT. The risk of MTCT increased if any of the main steps in the programme were missed.


Assuntos
Fármacos Anti-HIV/administração & dosagem , Quimioprevenção/métodos , Infecções por HIV/prevenção & controle , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Complicações Infecciosas na Gravidez/tratamento farmacológico , Fármacos Anti-HIV/uso terapêutico , Criança , Pré-Escolar , Estudos Transversais , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Humanos , Lactente , Malaui/epidemiologia , Gravidez , Complicações Infecciosas na Gravidez/prevenção & controle
9.
J Public Health (Oxf) ; 40(3): 567-572, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28977634

RESUMO

Background: Reducing or eliminating entrance charges for the public use of leisure facilities is one potential tool that local authorities (LA) have to reduce inequalities in physical activity (PA). Facility charges are likely to be a greater barrier to access for those who have lower incomes. Methods: Semi-structured 1-to-1 and group interviews were conducted with 33 leisure and public health professionals in seven LAs in north-west England. We investigated how approaches to pricing varied in these settings and rationales influencing decision making. Results: Welfare orientated (e.g. affordability) and commercial drivers (e.g. income generation) featured most prominently across areas. Pricing policies placed less direct focus on public health goals, although tackling inactivity was articulated as part of leisure's role more generally. Local targeting of free/concessionary offers was also defined and implemented differently. Decision makers described navigating competing pressures of providing services for the public 'good' yet remaining financially viable. Conclusion: Many LAs are reviewing the extent of subsidy for facilities or are considering whether to invest public health budgets in leisure. The findings offer evidence of how pricing decisions are made and the approaches adopted in practice as well as the conflicting priorities for decision makers within an austerity context.


Assuntos
Exercício Físico , Disparidades nos Níveis de Saúde , Atividades de Lazer/economia , Instalações Esportivas e Recreacionais/economia , Custos e Análise de Custo , Inglaterra , Promoção da Saúde/economia , Promoção da Saúde/métodos , Humanos , Entrevistas como Assunto , Governo Local , Saúde Pública , Pesquisa Qualitativa , Instalações Esportivas e Recreacionais/organização & administração
10.
Equine Vet Educ ; 30(2): 100-105, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32313395

RESUMO

Diarrhoea is a common problem in the neonatal and suckling foal. In certain circumstances supplemental nutrition is necessary depending on the age of foal, severity of diarrhoea and presence of other systemic manifestations. Nutritional supplementation can be provided either enterally or parenterally. Enteral nutrition is superior to parenteral nutrition because it is the most natural and physiologically sound means to provide nutritional support. Parenteral nutrition may be warranted if the foal is unable to receive or tolerate enteral nutrition. Dextrose alone or with amino acids and lipids can provide appropriate nutrition when enteral feeding is not tolerated. As soon as the foal stabilises enteral feeding can be reintroduced.

11.
Phys Rev Lett ; 118(15): 151102, 2017 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-28452534

RESUMO

Interferometric gravitational wave detectors operate with high optical power in their arms in order to achieve high shot-noise limited strain sensitivity. A significant limitation to increasing the optical power is the phenomenon of three-mode parametric instabilities, in which the laser field in the arm cavities is scattered into higher-order optical modes by acoustic modes of the cavity mirrors. The optical modes can further drive the acoustic modes via radiation pressure, potentially producing an exponential buildup. One proposed technique to stabilize parametric instability is active damping of acoustic modes. We report here the first demonstration of damping a parametrically unstable mode using active feedback forces on the cavity mirror. A 15 538 Hz mode that grew exponentially with a time constant of 182 sec was damped using electrostatic actuation, with a resulting decay time constant of 23 sec. An average control force of 0.03 nN was required to maintain the acoustic mode at its minimum amplitude.

12.
Phys Rev Lett ; 116(24): 241102, 2016 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-27367378

RESUMO

On September 14, 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected a gravitational-wave transient (GW150914); we characterize the properties of the source and its parameters. The data around the time of the event were analyzed coherently across the LIGO network using a suite of accurate waveform models that describe gravitational waves from a compact binary system in general relativity. GW150914 was produced by a nearly equal mass binary black hole of masses 36_{-4}^{+5}M_{⊙} and 29_{-4}^{+4}M_{⊙}; for each parameter we report the median value and the range of the 90% credible interval. The dimensionless spin magnitude of the more massive black hole is bound to be <0.7 (at 90% probability). The luminosity distance to the source is 410_{-180}^{+160} Mpc, corresponding to a redshift 0.09_{-0.04}^{+0.03} assuming standard cosmology. The source location is constrained to an annulus section of 610 deg^{2}, primarily in the southern hemisphere. The binary merges into a black hole of mass 62_{-4}^{+4}M_{⊙} and spin 0.67_{-0.07}^{+0.05}. This black hole is significantly more massive than any other inferred from electromagnetic observations in the stellar-mass regime.

13.
Phys Rev Lett ; 116(24): 241103, 2016 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-27367379

RESUMO

We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, and reached a peak gravitational strain of 3.4_{-0.9}^{+0.7}×10^{-22}. The inferred source-frame initial black hole masses are 14.2_{-3.7}^{+8.3}M_{⊙} and 7.5_{-2.3}^{+2.3}M_{⊙}, and the final black hole mass is 20.8_{-1.7}^{+6.1}M_{⊙}. We find that at least one of the component black holes has spin greater than 0.2. This source is located at a luminosity distance of 440_{-190}^{+180} Mpc corresponding to a redshift of 0.09_{-0.04}^{+0.03}. All uncertainties define a 90% credible interval. This second gravitational-wave observation provides improved constraints on stellar populations and on deviations from general relativity.

14.
Phys Rev Lett ; 116(22): 221101, 2016 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-27314708

RESUMO

The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 10^{13} km. In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.

15.
Phys Rev Lett ; 116(13): 131103, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27081966

RESUMO

Following a major upgrade, the two advanced detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) held their first observation run between September 2015 and January 2016. With a strain sensitivity of 10^{-23}/sqrt[Hz] at 100 Hz, the product of observable volume and measurement time exceeded that of all previous runs within the first 16 days of coincident observation. On September 14, 2015, the Advanced LIGO detectors observed a transient gravitational-wave signal determined to be the coalescence of two black holes [B. P. Abbott et al., Phys. Rev. Lett. 116, 061102 (2016)], launching the era of gravitational-wave astronomy. The event, GW150914, was observed with a combined signal-to-noise ratio of 24 in coincidence by the two detectors. Here, we present the main features of the detectors that enabled this observation. At full sensitivity, the Advanced LIGO detectors are designed to deliver another factor of 3 improvement in the signal-to-noise ratio for binary black hole systems similar in mass to GW150914.

16.
Phys Rev Lett ; 116(13): 131102, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27081965

RESUMO

The LIGO detection of the gravitational wave transient GW150914, from the inspiral and merger of two black holes with masses ≳30M_{⊙}, suggests a population of binary black holes with relatively high mass. This observation implies that the stochastic gravitational-wave background from binary black holes, created from the incoherent superposition of all the merging binaries in the Universe, could be higher than previously expected. Using the properties of GW150914, we estimate the energy density of such a background from binary black holes. In the most sensitive part of the Advanced LIGO and Advanced Virgo band for stochastic backgrounds (near 25 Hz), we predict Ω_{GW}(f=25 Hz)=1.1_{-0.9}^{+2.7}×10^{-9} with 90% confidence. This prediction is robustly demonstrated for a variety of formation scenarios with different parameters. The differences between models are small compared to the statistical uncertainty arising from the currently poorly constrained local coalescence rate. We conclude that this background is potentially measurable by the Advanced LIGO and Advanced Virgo detectors operating at their projected final sensitivity.

17.
Vet Pathol ; 53(3): 674-6, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26374278

RESUMO

Canine distemper virus commonly infects free-ranging, terrestrial mesopredators throughout the United States. Due to the immunosuppressive effects of the virus, concurrent opportunistic infections are also common. Among these, secondary systemic protozoal infections have been described in a number of species. We report an unusual presentation of necrotizing encephalitis associated withSarcocystissp in four raccoons and one skunk concurrently infected with canine distemper virus. Lesions were characterized by variably sized necrotizing cavitations composed of abundant mineral admixed with inflammatory cells and protozoa.Sarcocystissp was confirmed via immunohistochemistry using a monoclonal antibody toSarcocystis neurona The pathologic changes are similar to lesions in human AIDS patients infected withToxoplasma gondii.


Assuntos
Vírus da Cinomose Canina , Cinomose/diagnóstico , Encefalite Infecciosa/veterinária , Mephitidae , Guaxinins , Sarcocistose/veterinária , Animais , Calcinose/veterinária , Cinomose/complicações , Cinomose/patologia , Cinomose/virologia , Vírus da Cinomose Canina/isolamento & purificação , Imuno-Histoquímica/veterinária , Encefalite Infecciosa/complicações , Encefalite Infecciosa/diagnóstico , Encefalite Infecciosa/patologia , Mephitidae/parasitologia , Mephitidae/virologia , Necrose/veterinária , Guaxinins/parasitologia , Guaxinins/virologia , Sarcocystis/imunologia , Sarcocystis/isolamento & purificação , Sarcocistose/complicações , Sarcocistose/diagnóstico , Sarcocistose/patologia , Estados Unidos
18.
Living Rev Relativ ; 19(1): 1, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28179853

RESUMO

We present a possible observing scenario for the Advanced LIGO and Advanced Virgo gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We determine the expected sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron-star systems, which are considered the most promising for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and 90% credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5 deg2 to 20 deg2 will require at least three detectors of sensitivity within a factor of ∼ 2 of each other and with a broad frequency bandwidth. Should the third LIGO detector be relocated to India as expected, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

19.
Nature ; 460(7258): 990-4, 2009 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-19693079

RESUMO

A stochastic background of gravitational waves is expected to arise from a superposition of a large number of unresolved gravitational-wave sources of astrophysical and cosmological origin. It should carry unique signatures from the earliest epochs in the evolution of the Universe, inaccessible to standard astrophysical observations. Direct measurements of the amplitude of this background are therefore of fundamental importance for understanding the evolution of the Universe when it was younger than one minute. Here we report limits on the amplitude of the stochastic gravitational-wave background using the data from a two-year science run of the Laser Interferometer Gravitational-wave Observatory (LIGO). Our result constrains the energy density of the stochastic gravitational-wave background normalized by the critical energy density of the Universe, in the frequency band around 100 Hz, to be <6.9 x 10(-6) at 95% confidence. The data rule out models of early Universe evolution with relatively large equation-of-state parameter, as well as cosmic (super)string models with relatively small string tension that are favoured in some string theory models. This search for the stochastic background improves on the indirect limits from Big Bang nucleosynthesis and cosmic microwave background at 100 Hz.

20.
Phys Rev Lett ; 113(23): 231101, 2014 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-25526109

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 Ω_{GW}(f)=Ω_{α}(f/f_{ref})^{α}, 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 α=0, we constrain the energy density of the stochastic background to be Ω_{GW}(f)<5.6×10^{-6}. For the 600-1000 Hz band, Ω_{GW}(f)<0.14(f/900 Hz)^{3}, a factor of 2.5 lower than the best previously reported upper limits. We find Ω_{GW}(f)<1.8×10^{-4} using a spectral index of zero for 170-600 Hz and Ω_{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.

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