Suchergebnisse

Despite almost three decades of the Universal Immunization Program in India, a little more than half the children aged 12-23months receive the full schedule of routine vaccinations. We examined socio-demographic factors associated with partial-vaccination and non-vaccination and the reasons for non-vaccination among Indian children during 1998 and 2008. Data from three consecutive, nationally-representative, District Level Household and Facility Surveys (1998-99, 2002-04 and 2007-08) were pooled. Multinomial logistic regression was used to identify individual and household level socio-demographic variables associated with the child's vaccination status. The mother's reported reasons for non-vaccination were analyzed qualitatively, adapting from a previously published framework. The pooled dataset contained information on 178,473 children 12-23months of age; 53%, 32% and 15% were fully vaccinated, partially vaccinated and unvaccinated respectively. Compared with the 1998-1999 survey, children in the 2007-2008 survey were less likely to be unvaccinated (Adjusted Prevalence Odds Ratio (aPOR): 0.92, 95%CI=0.86-0.98) but more likely to be partially vaccinated (aPOR: 1.58, 95%CI=1.52-1.65). Vaccination status was inversely associated with female gender, Muslim religion, lower caste, urban residence and maternal characteristics such as lower educational attainment, non-institutional delivery, fewer antenatal care visits and non-receipt of maternal tetanus vaccination. The mother's reported reasons for non-vaccination indicated gaps in awareness, acceptance and affordability (financial and non-financial costs) related to routine vaccinations. Persisting socio-demographic disparities related to partial-vaccination and non-vaccination were associated with important childhood, maternal and household characteristics. Further research investigating the causal pathways through which maternal and social characteristics influence decision-making for childhood vaccinations is needed to improve uptake of routine vaccination in India. Also, efforts to increase uptake should address parental fears related to vaccination to improve trust in government health services as part of ongoing social mobilization and communication strategies.

Background Established in 2000, Millennium Development Goal 4 (MDG4) catalysed extraordinary political, fi nancial, and social commitments to reduce under-5 mortality by two-thirds between 1990 and 2015. At the country level, the pace of progress in improving child survival has varied markedly, highlighting a crucial need to further examine potential drivers of accelerated or slowed decreases in child mortality. The Global Burden of Disease 2015 Study (GBD 2015) provides an analytical framework to comprehensively assess these trends for under-5 mortality, age-specifi c and cause-specifi c mortality among children under 5 years, and stillbirths by geography over time. Methods Drawing from analytical approaches developed and refi ned in previous iterations of the GBD study, we generated updated estimates of child mortality by age group (neonatal, post-neonatal, ages 1–4 years, and under 5) for 195 countries and territories and selected subnational geographies, from 1980–2015. We also estimated numbers and rates of stillbirths for these geographies and years. Gaussian process regression with data source adjustments for sampling and non-sampling bias was applied to synthesise input data for under-5 mortality for each geography. Age-specifi c mortality estimates were generated through a two-stage age–sex splitting process, and stillbirth estimates were produced with a mixed-eff ects model, which accounted for variable stillbirth defi nitions and data source-specifi c biases. For GBD 2015, we did a series of novel analyses to systematically quantify the drivers of trends in child mortality across geographies. First, we assessed observed and expected levels and annualised rates of decrease for under-5 mortality and stillbirths as they related to the Soci-demographic Index (SDI). Second, we examined the ratio of recorded and expected levels of child mortality, on the basis of SDI, across geographies, as well as diff erences in recorded and expected annualised rates of change for under-5 mortality. Third, we analysed levels and cause compositions of under-5 mortality, across time and geographies, as they related to rising SDI. Finally, we decomposed the changes in under-5 mortality to changes in SDI at the global level, as well as changes in leading causes of under-5 deaths for countries and territories. We documented each step of the GBD 2015 child mortality estimation process, as well as data sources, in accordance with the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER). Findings Globally, 5·8 million (95% uncertainty interval [UI] 5·7–6·0) children younger than 5 years died in 2015, representing a 52·0% (95% UI 50·7–53·3) decrease in the number of under-5 deaths since 1990. Neonatal deaths and stillbirths fell at a slower pace since 1990, decreasing by 42·4% (41·3–43·6) to 2·6 million (2·6–2·7) neonatal deaths and 47·0% (35·1–57·0) to 2·1 million (1·8-2·5) stillbirths in 2015. Between 1990 and 2015, global under-5 mortality decreased at an annualised rate of decrease of 3·0% (2·6–3·3), falling short of the 4·4% annualised rate of decrease required to achieve MDG4. During this time, 58 countries met or exceeded the pace of progress required to meet MDG4. Between 2000, the year MDG4 was formally enacted, and 2015, 28 additional countries that did not achieve the 4·4% rate of decrease from 1990 met the MDG4 pace of decrease. However, absolute levels of under-5 mortality remained high in many countries, with 11 countries still recording rates exceeding 100 per 1000 livebirths in 2015. Marked decreases in under-5 deaths due to a number of communicable diseases, including lower respiratory infections, diarrhoeal diseases, measles, and malaria, accounted for much of the progress in lowering overall under-5 mortality in low-income countries. Compared with gains achieved for infectious diseases and nutritional defi ciencies, the persisting toll of neonatal conditions and congenital anomalies on child survival became evident, especially in low-income and low-middle-income countries. We found sizeable heterogeneities in comparing observed and expected rates of under-5 mortality, as well as diff erences in observed and expected rates of change for under-5 mortality. At the global level, we recorded a divergence in observed and expected levels of under-5 mortality starting in 2000, with the observed trend falling much faster than what was expected based on SDI through 2015. Between 2000 and 2015, the world recorded 10·3 million fewer under-5 deaths than expected on the basis of improving SDI alone. Interpretation Gains in child survival have been large, widespread, and in many places in the world, faster than what was anticipated based on improving levels of development. Yet some countries, particularly in sub-Saharan Africa, still had high rates of under-5 mortality in 2015. Unless these countries are able to accelerate reductions in child deaths at an extraordinary pace, their achievement of proposed SDG targets is unlikely. Improving the evidence base on drivers that might hasten the pace of progress for child survival, ranging from cost-eff ective intervention packages to innovative fi nancing mechanisms, is vital to charting the pathways for ultimately ending preventable child deaths by 2030.

Background Established in 2000, Millennium Development Goal 4 (MDG4) catalysed extraordinary political, fi nancial, and social commitments to reduce under-5 mortality by two-thirds between 1990 and 2015. At the country level, the pace of progress in improving child survival has varied markedly, highlighting a crucial need to further examine potential drivers of accelerated or slowed decreases in child mortality. The Global Burden of Disease 2015 Study (GBD 2015) provides an analytical framework to comprehensively assess these trends for under-5 mortality, age-specifi c and cause-specifi c mortality among children under 5 years, and stillbirths by geography over time. Methods Drawing from analytical approaches developed and refi ned in previous iterations of the GBD study, we generated updated estimates of child mortality by age group (neonatal, post-neonatal, ages 1–4 years, and under 5) for 195 countries and territories and selected subnational geographies, from 1980–2015. We also estimated numbers and rates of stillbirths for these geographies and years. Gaussian process regression with data source adjustments for sampling and non-sampling bias was applied to synthesise input data for under-5 mortality for each geography. Age-specifi c mortality estimates were generated through a two-stage age–sex splitting process, and stillbirth estimates were produced with a mixed-eff ects model, which accounted for variable stillbirth defi nitions and data source-specifi c biases. For GBD 2015, we did a series of novel analyses to systematically quantify the drivers of trends in child mortality across geographies. First, we assessed observed and expected levels and annualised rates of decrease for under-5 mortality and stillbirths as they related to the Soci-demographic Index (SDI). Second, we examined the ratio of recorded and expected levels of child mortality, on the basis of SDI, across geographies, as well as diff erences in recorded and expected annualised rates of change for under-5 mortality. Third, we analysed levels and cause compositions of under-5 mortality, across time and geographies, as they related to rising SDI. Finally, we decomposed the changes in under-5 mortality to changes in SDI at the global level, as well as changes in leading causes of under-5 deaths for countries and territories. We documented each step of the GBD 2015 child mortality estimation process, as well as data sources, in accordance with the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER). Findings Globally, 5·8 million (95% uncertainty interval [UI] 5·7–6·0) children younger than 5 years died in 2015, representing a 52·0% (95% UI 50·7–53·3) decrease in the number of under-5 deaths since 1990. Neonatal deaths and stillbirths fell at a slower pace since 1990, decreasing by 42·4% (41·3–43·6) to 2·6 million (2·6–2·7) neonatal deaths and 47·0% (35·1–57·0) to 2·1 million (1·8-2·5) stillbirths in 2015. Between 1990 and 2015, global under-5 mortality decreased at an annualised rate of decrease of 3·0% (2·6–3·3), falling short of the 4·4% annualised rate of decrease required to achieve MDG4. During this time, 58 countries met or exceeded the pace of progress required to meet MDG4. Between 2000, the year MDG4 was formally enacted, and 2015, 28 additional countries that did not achieve the 4·4% rate of decrease from 1990 met the MDG4 pace of decrease. However, absolute levels of under-5 mortality remained high in many countries, with 11 countries still recording rates exceeding 100 per 1000 livebirths in 2015. Marked decreases in under-5 deaths due to a number of communicable diseases, including lower respiratory infections, diarrhoeal diseases, measles, and malaria, accounted for much of the progress in lowering overall under-5 mortality in low-income countries. Compared with gains achieved for infectious diseases and nutritional defi ciencies, the persisting toll of neonatal conditions and congenital anomalies on child survival became evident, especially in low-income and low-middle-income countries. We found sizeable heterogeneities in comparing observed and expected rates of under-5 mortality, as well as diff erences in observed and expected rates of change for under-5 mortality. At the global level, we recorded a divergence in observed and expected levels of under-5 mortality starting in 2000, with the observed trend falling much faster than what was expected based on SDI through 2015. Between 2000 and 2015, the world recorded 10·3 million fewer under-5 deaths than expected on the basis of improving SDI alone. Interpretation Gains in child survival have been large, widespread, and in many places in the world, faster than what was anticipated based on improving levels of development. Yet some countries, particularly in sub-Saharan Africa, still had high rates of under-5 mortality in 2015. Unless these countries are able to accelerate reductions in child deaths at an extraordinary pace, their achievement of proposed SDG targets is unlikely. Improving the evidence base on drivers that might hasten the pace of progress for child survival, ranging from cost-eff ective intervention packages to innovative fi nancing mechanisms, is vital to charting the pathways for ultimately ending preventable child deaths by 2030.

Background Established in 2000, Millennium Development Goal 4 (MDG4) catalysed extraordinary political, financial, and social commitments to reduce under-5 mortality by two-thirds between 1990 and 2015. At the country level, the pace of progress in improving child survival has varied markedly, highlighting a crucial need to further examine potential drivers of accelerated or slowed decreases in child mortality. The Global Burden of Disease 2015 Study (GBD 2015) provides an analytical framework to comprehensively assess these trends for under-5 mortality, age-specific and cause-specific mortality among children under 5 years, and stillbirths by geography over time. Methods Drawing from analytical approaches developed and refined in previous iterations of the GBD study, we generated updated estimates of child mortality by age group (neonatal, post-neonatal, ages 1�4 years, and under 5) for 195 countries and territories and selected subnational geographies, from 1980�2015. We also estimated numbers and rates of stillbirths for these geographies and years. Gaussian process regression with data source adjustments for sampling and non-sampling bias was applied to synthesise input data for under-5 mortality for each geography. Age-specific mortality estimates were generated through a two-stage age�sex splitting process, and stillbirth estimates were produced with a mixed-effects model, which accounted for variable stillbirth definitions and data source-specific biases. For GBD 2015, we did a series of novel analyses to systematically quantify the drivers of trends in child mortality across geographies. First, we assessed observed and expected levels and annualised rates of decrease for under-5 mortality and stillbirths as they related to the Soci-demographic Index (SDI). Second, we examined the ratio of recorded and expected levels of child mortality, on the basis of SDI, across geographies, as well as differences in recorded and expected annualised rates of change for under-5 mortality. Third, we analysed levels and cause compositions of under-5 mortality, across time and geographies, as they related to rising SDI. Finally, we decomposed the changes in under-5 mortality to changes in SDI at the global level, as well as changes in leading causes of under-5 deaths for countries and territories. We documented each step of the GBD 2015 child mortality estimation process, as well as data sources, in accordance with the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER). Findings Globally, 5·8 million (95 uncertainty interval UI 5·7�6·0) children younger than 5 years died in 2015, representing a 52·0% (95% UI 50·7�53·3) decrease in the number of under-5 deaths since 1990. Neonatal deaths and stillbirths fell at a slower pace since 1990, decreasing by 42·4% (41·3�43·6) to 2·6 million (2·6�2·7) neonatal deaths and 47·0% (35·1�57·0) to 2·1 million (1·8-2·5) stillbirths in 2015. Between 1990 and 2015, global under-5 mortality decreased at an annualised rate of decrease of 3·0% (2·6�3·3), falling short of the 4·4% annualised rate of decrease required to achieve MDG4. During this time, 58 countries met or exceeded the pace of progress required to meet MDG4. Between 2000, the year MDG4 was formally enacted, and 2015, 28 additional countries that did not achieve the 4·4% rate of decrease from 1990 met the MDG4 pace of decrease. However, absolute levels of under-5 mortality remained high in many countries, with 11 countries still recording rates exceeding 100 per 1000 livebirths in 2015. Marked decreases in under-5 deaths due to a number of communicable diseases, including lower respiratory infections, diarrhoeal diseases, measles, and malaria, accounted for much of the progress in lowering overall under-5 mortality in low-income countries. Compared with gains achieved for infectious diseases and nutritional deficiencies, the persisting toll of neonatal conditions and congenital anomalies on child survival became evident, especially in low-income and low-middle-income countries. We found sizeable heterogeneities in comparing observed and expected rates of under-5 mortality, as well as differences in observed and expected rates of change for under-5 mortality. At the global level, we recorded a divergence in observed and expected levels of under-5 mortality starting in 2000, with the observed trend falling much faster than what was expected based on SDI through 2015. Between 2000 and 2015, the world recorded 10·3 million fewer under-5 deaths than expected on the basis of improving SDI alone. Interpretation Gains in child survival have been large, widespread, and in many places in the world, faster than what was anticipated based on improving levels of development. Yet some countries, particularly in sub-Saharan Africa, still had high rates of under-5 mortality in 2015. Unless these countries are able to accelerate reductions in child deaths at an extraordinary pace, their achievement of proposed SDG targets is unlikely. Improving the evidence base on drivers that might hasten the pace of progress for child survival, ranging from cost-effective intervention packages to innovative financing mechanisms, is vital to charting the pathways for ultimately ending preventable child deaths by 2030. Funding Bill & Melinda Gates Foundation. © 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license.

United States National Science Foundation (NSF) ; Science and Technology Facilities Council (STFC) of the United Kingdom ; Max-Planck-Society (MPS) ; State of Niedersachsen/Germany ; Australian Research Council ; International Science Linkages program of the Commonwealth of Australia ; Council of Scientific and Industrial Research of India ; Department of Science and Technology, India ; Science & Engineering Research Board (SERB), India ; Ministry of Human Resource Development, India ; Spanish Ministerio de Economia y Competitividad ; Conselleria d'Economia i Competitivitat and Conselleria d'Educaci, Cultura i Universitats of the Govern de les Illes Balears ; Foundation for Fundamental Research on Matter - Netherlands Organization for Scientific Research ; Polish Ministry of Science and Higher Education ; FOCUS Programme of Foundation for Polish Science ; European Union ; Royal Society ; Scottish Funding Council ; Scottish Universities Physics Alliance ; National Aeronautics and Space Administration ; Hungarian Scientific Research Fund (OTKA) ; Lyon Institute of Origins (LIO) ; National Research Foundation of Korea ; Industry Canada ; Province of Ontario through the Ministry of Economic Development and Innovation ; National Science and Engineering Research Council Canada ; Brazilian Ministry of Science, Technology, and Innovation ; Carnegie Trust ; Leverhulme Trust ; David and Lucile Packard Foundation ; Research Corporation ; Alfred P. Sloan Foundation ; NSF ; STFC ; MPS ; INFN ; CNRS ; Science and Technology Facilities Council ; Science and Technology Facilities Council: ST/L000938/1 ; Science and Technology Facilities Council: ST/I006285/1 ; Science and Technology Facilities Council: ST/I006269/1 ; Science and Technology Facilities Council: ST/L000946/1 ; Science and Technology Facilities Council: ST/L000962/1 ; Science and Technology Facilities Council: ST/L003465/1 ; Science and Technology Facilities Council: ST/K000845/1 ; Science and Technology Facilities Council: ST/J00166X/1 ; Science and Technology Facilities Council: ST/L000911/1 Gravitational Waves ; Science and Technology Facilities Council: Gravitational Waves ; Science and Technology Facilities Council: PPA/G/S/2002/00652 ; Science and Technology Facilities Council: ST/I006269/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000911/1 ; Science and Technology Facilities Council: 1362895 ; Science and Technology Facilities Council: ST/I006277/1 ; Science and Technology Facilities Council: ST/H002359/1 ; Science and Technology Facilities Council: ST/K005014/1 ; Science and Technology Facilities Council: ST/K00137X/1 ; Science and Technology Facilities Council: ST/M006735/1 ; Science and Technology Facilities Council: ST/M000931/1 ; Science and Technology Facilities Council: ST/L000938/1 Gravitational Waves ; We describe directed searches for continuous gravitational waves (GWs) in data from the sixth Laser Interferometer Gravitational-wave Observatory (LIGO) science data run. The targets were nine young supernova remnants not associated with pulsars; eight of the remnants are associated with non-pulsing suspected neutron stars. One target ' s parameters are uncertain enough to warrant two searches, for a total of 10. Each search covered a broad band of frequencies and first and second frequency derivatives for a fixed sky direction. The searches coherently integrated data from the two LIGO interferometers over time spans from 5.3-25.3 days using the matched-filtering. -statistic. We found no evidence of GW signals. We set 95% confidence upper limits as strong (low) as 4 x 10(-25) on intrinsic strain, 2 x 10(-7) on fiducial ellipticity, and 4 x 10(-5) on r-mode amplitude. These beat the indirect limits from energy conservation and are within the range of theoretical predictions for neutron-star ellipticities and r-mode amplitudes.

United States National Science Foundation (NSF) ; Science and Technology Facilities Council (STFC) of the United Kingdom ; Max-Planck-Society (MPS) ; State of Niedersachsen/Germany ; Italian Istituto Nazionale di Fisica Nucleare (INFN) ; French Centre National de la Recherche Scientifique (CNRS) ; Australian Research Council ; International Science Linkages program of the Commonwealth of Australia ; Council of Scientific and Industrial Research of India ; Department of Science and Technology, India ; Science & Engineering Research Board (SERB), India ; Ministry of Human Resource Development, India ; Spanish Ministerio de Economia y Competitividad ; Conselleria d'Economia i Competitivitat and Conselleria d'Educaci, Cultura i Universitats of the Govern de les Illes Balears ; Netherlands Organisation for Scientific Research ; National Science Centre of Poland ; European Union ; Royal Society ; Scottish Funding Council ; Scottish Universities Physics Alliance ; National Aeronautics and Space Administration ; Hungarian Scientific Research Fund (OTKA) ; Lyon Institute of Origins (LIO) ; National Research Foundation of Korea ; Industry Canada ; Province of Ontario through the Ministry of Economic Development and Innovation ; Natural Science and Engineering Research Council, Canada ; Brazilian Ministry of Science, Technology, and Innovation ; Carnegie Trust ; Leverhulme Trust ; David and Lucile Packard Foundation ; Research Corporation ; Alfred P. Sloan Foundation ; NSF ; STFC ; MPS ; INFN ; CNRS ; Science and Technology Facilities Council ; Science and Technology Facilities Council: ST/L000938/1 Gravitational Waves ; Science and Technology Facilities Council: 1362895 ; Science and Technology Facilities Council: ST/L000962/1 ; Science and Technology Facilities Council: ST/I006285/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L003465/1 ; Science and Technology Facilities Council: ST/L000962/1 Gravitational Waves ; Science and Technology Facilities Council: ST/I006285/1 ; Science and Technology Facilities Council: ST/I006242/1 Gravitational Waves ; Science and Technology Facilities Council: ST/J000019/1 ; Science and Technology Facilities Council: ST/N00003X/1 ; Science and Technology Facilities Council: ST/L000946/1 ; Science and Technology Facilities Council: ST/N000064/1 ; Science and Technology Facilities Council: ST/L000954/1 Gravitational Waves ; Science and Technology Facilities Council: ST/K000845/1 ; Science and Technology Facilities Council: ST/I006269/1 ; Science and Technology Facilities Council: ST/L000938/1 ; Science and Technology Facilities Council: Gravitational Waves ; Science and Technology Facilities Council: ST/K005014/1 ; Science and Technology Facilities Council: ST/I006269/1 Gravitational Waves ; We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4 x 10(-5) and 9.4 x 10(-4) Mpc(-3) yr(-1) at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves.

Advanced LIGO ; Science and Technology Facilities Council (STFC) of the United Kingdom ; Australian Research Council ; Council of Scientific and Industrial Research of India, Department of Science and Technology, India ; Science & Engineering Research Board (SERB), India ; Ministry of Human Resource Development, India ; Spanish Ministerio de Economia y Competitividad ; Conselleria d'Economia i Competitivitat and Conselleria d'Educacio, Cultura i Universitats of the Govern de les Illes Balears ; National Science Centre of Poland ; FOCUS Programme of Foundation for Polish Science ; European Union ; Royal Society ; Scottish Funding Council ; Scottish Universities Physics Alliance ; Lyon Institute of Origins (LIO) ; National Research Foundation of Korea ; Industry Canada ; Province of Ontario through the Ministry of Economic Development and Innovation ; National Science and Engineering Research Council Canada ; Brazilian Ministry of Science, Technology, and Innovation ; Research Corporation, Ministry of Science and Technology (MOST), Taiwan ; Kavli Foundation ; Science and Technology Facilities Council ; Science and Technology Facilities Council: ST/L000954/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000946/1 ; Science and Technology Facilities Council: ST/I006269/1 Gravitational Waves ; Science and Technology Facilities Council: ST/I006242/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L003465/1 ; Science and Technology Facilities Council: ST/J000019/1 ; Science and Technology Facilities Council: ST/N000072/1 ; Science and Technology Facilities Council: ST/K000845/1 ; Science and Technology Facilities Council: ST/I006269/1 ; Science and Technology Facilities Council: ST/N000633/1 ; Science and Technology Facilities Council: ST/M000931/1 ; Science and Technology Facilities Council: ST/K005014/1 ; Science and Technology Facilities Council: PPA/G/S/2002/00652 ; Science and Technology Facilities Council: Gravitational Waves ; Science and Technology Facilities Council: ST/N00003X/1 ; 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 deg(2) to 20 deg(2) will require at least three detectors of sensitivity within a factor of similar to 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.

Australian Research Council ; International Science Linkages program of the Commonwealth of Australia ; Council of Scientific and Industrial Research of India, Department of Science and Technology, India ; Science and Engineering Research Board, India ; Ministry of Human Resource Development, India ; Spanish Ministerio de Economia y Competitividad ; Conselleria d'Economia i Competitivitat ; Cultura i Universitats of the Govern de les Illes Balears ; Foundation for Fundamental Research on Matter - Netherlands Organisation for Scientific Research ; National Science Centre of Poland ; European Union ; Royal Society ; Scottish Funding Council ; Scottish Universities Physics Alliance ; National Aeronautics and Space Administration ; Hungarian Scientific Research Fund ; Lyon Institute of Origins ; National Research Foundation of Korea ; Industry Canada ; Province of Ontario through the Ministry of Economic Development and Innovation ; National Science and Engineering Research Council Canada ; Brazilian Ministry of Science, Technology, and Innovation ; Carnegie Trust ; Leverhulme Trust ; David and Lucile Packard Foundation ; Research Corporation ; Alfred P. Sloan Foundation ; Conselleria d'Educacio ; Science and Technology Facilities Council ; Science and Technology Facilities Council: ST/L000962/1 Gravitational Waves ; Science and Technology Facilities Council: 1362895 ; Science and Technology Facilities Council: ST/I006285/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000938/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000962/1 ; Science and Technology Facilities Council: ST/K000845/1 ; Science and Technology Facilities Council: Gravitational Waves ; Science and Technology Facilities Council: ST/K005014/1 ; Science and Technology Facilities Council: ST/L003465/1 ; Science and Technology Facilities Council: ST/L000938/1 ; Science and Technology Facilities Council: ST/N000064/1 ; Science and Technology Facilities Council: ST/L000946/1 ; Science and Technology Facilities Council: ST/L000954/1 Gravitational Waves ; Science and Technology Facilities Council: ST/I006269/1 Gravitational Waves ; Science and Technology Facilities Council: ST/I006269/1 ; Science and Technology Facilities Council: ST/J000019/1 ; Science and Technology Facilities Council: ST/I006242/1 Gravitational Waves ; In this paper we present the results of the first low frequency all-sky search of continuous gravitational wave signals conducted on Virgo VSR2 and VSR4 data. The search covered the full sky, a frequency range between 20 and 128 Hz with a range of spin-down between -1.0 x 10(-10) and +1.5 x 10(-11) Hz/s, and was based on a hierarchical approach. The starting point was a set of short fast Fourier transforms, of length 8192 s, built from the calibrated strain data. Aggressive data cleaning, in both the time and frequency domains, has been done in order to remove, as much as possible, the effect of disturbances of instrumental origin. On each data set a number of candidates has been selected, using the Frequency Hough transform in an incoherent step. Only coincident candidates among VSR2 and VSR4 have been examined in order to strongly reduce the false alarm probability, and the most significant candidates have been selected. The criteria we have used for candidate selection and for the coincidence step greatly reduce the harmful effect of large instrumental artifacts. Selected candidates have been subject to a follow-up by constructing a new set of longer fast Fourier transforms followed by a further incoherent analysis, still based on the Frequency Hough transform. No evidence for continuous gravitational wave signals was found, and therefore we have set a population-based joint VSR2-VSR4 90% confidence level upper limit on the dimensionless gravitational wave strain in the frequency range between 20 and 128 Hz. This is the first all-sky search for continuous gravitational waves conducted, on data of ground-based interferometric detectors, at frequencies below 50 Hz. We set upper limits in the range between about 10(-24) and 2 x 10(-23) at most frequencies. Our upper limits on signal strain show an improvement of up to a factor of similar to 2 with respect to the results of previous all-sky searches at frequencies below 80 Hz.

United States National Science Foundation (NSF) ; Science and Technology Facilities Council (STFC) of the United Kingdom ; MaxPlanck- Society (MPS) ; State of Niedersachsen/Germany ; Australian Research Council ; Netherlands Organisation for Scientific Research ; EGO consortium ; Council of Scientific and Industrial Research of India, Department of Science and Technology, India ; Science AMP; Engineering Research Board (SERB), India ; Ministry of Human Resource Development, India ; Spanish Ministerio de Economia y Competitividad ; Conselleria d'Economia i Competitivitat and Conselleria d'Educacio Cultura i Universitats of the Govern de les Illes Balears ; National Science Centre of Poland ; European Union ; Royal Society ; Scottish Funding Council ; Scottish Universities Physics Alliance ; Lyon Institute of Origins (LIO) ; National Research Foundation of Korea, Industry Canada ; Province of Ontario through the Ministry of Economic Development and Innovation ; National Science and Engineering Research Council Canada ; Brazilian Ministry of Science, Technology, and Innovation ; Leverhulme Trust ; Research Corporation, Ministry of Science and Technology (MOST), Taiwan ; Kavli Foundation ; NSF ; STFC ; MPS ; INFN ; CNRS ; Science and Technology Facilities Council ; State of Niedersachsen/Germany: GEO600 ; Science and Technology Facilities Council: ST/K005014/1 ; Science and Technology Facilities Council: ST/L000938/1 Gravitational Waves ; Science and Technology Facilities Council: ST/N000072/1 ; Science and Technology Facilities Council: PPA/G/S/2002/00652 ; Science and Technology Facilities Council: ST/I006269/1 ; Science and Technology Facilities Council: ST/L000962/1 ; Science and Technology Facilities Council: ST/J00166X/1 ; Science and Technology Facilities Council: ST/M006735/1 ; Science and Technology Facilities Council: ST/I006285/1 Gravitational Waves ; Science and Technology Facilities Council: ST/J000019/1 Gravitational Waves ; Science and Technology Facilities Council: ST/I006285/1 ; Science and Technology Facilities Council: ST/J000019/1 ; Science and Technology Facilities Council: 1362895 ; Science and Technology Facilities Council: ST/M000931/1 ; Science and Technology Facilities Council: ST/L000962/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000938/1 ; Science and Technology Facilities Council: ST/K000845/1 ; Science and Technology Facilities Council: ST/I006242/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L003465/1 ; Science and Technology Facilities Council: ST/G504284/1 ; Science and Technology Facilities Council: ST/I006269/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000954/1 Gravitational Waves ; Science and Technology Facilities Council: ST/N00003X/1 ; Science and Technology Facilities Council: Gravitational Waves ; Science and Technology Facilities Council: ST/N000633/1 ; Science and Technology Facilities Council: ST/L000946/1 ; The discovery of the gravitational-wave (GW) source GW150914 with the Advanced LIGO detectors provides the first observational evidence for the existence of binary black hole (BH) systems that inspiral and merge within the age of the universe. Such BH mergers have been predicted in two main types of formation models, involving isolated binaries in galactic fields or dynamical interactions in young and old dense stellar environments. The measured masses robustly demonstrate that relatively heavy BHs (greater than or similar to 25M(circle dot)) can form in nature. This discovery implies relatively weak massive-star winds and thus the formation of GW150914 in an environment with a metallicity lower than about 1/2 of the solar value. The rate of binary-BH (BBH) mergers inferred from the observation of GW150914 is consistent with the higher end of rate predictions (greater than or similar to 1 Gpc(-3) yr(-1)) from both types of formation models. The low measured redshift (z similar or equal to 0.1) of GW150914 and the low inferred metallicity of the stellar progenitor imply either BBH formation in a low-mass galaxy in the local universe and a prompt merger, or formation at high redshift with a time delay between formation and merger of several Gyr. This discovery motivates further studies of binary-BH formation astrophysics. It also has implications for future detections and studies by Advanced LIGO and Advanced Virgo, and GW detectors in space.