The Experts below are selected from a list of 150360 Experts worldwide ranked by ideXlab platform
Clara Cilindre - One of the best experts on this subject based on the ideXlab platform.
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unveiling co 2 heterogeneous freezing plumes during champagne cork popping
Scientific Reports, 2017Co-Authors: Gerard Ligerbelair, Daniel Cordier, Jacques Honvault, Clara CilindreAbstract:Cork popping from clear transparent bottles of champagne stored at different temperatures (namely, 6, 12, and 20 °C) was filmed through high-speed video imaging in the visible light spectrum. During the cork popping process, a plume mainly composed of gaseous CO2 with traces of water vapour freely expands out of the Bottleneck through ambient air. Most interestingly, for the bottles stored at 20 °C, the characteristic grey-white cloud of fog classically observed above the Bottlenecks of champagne stored at lower temperatures simply disappeared. It is replaced by a more evanescent plume, surprisingly blue, starting from the Bottleneck. We suggest that heterogeneous freezing of CO2 occurs on ice water clusters homogeneously nucleated in the Bottlenecks, depending on the saturation ratio experienced by gas-phase CO2 after adiabatic expansion (indeed highly bottle temperature dependent). Moreover, and as observed for the bottles stored at 20 °C, we show that the freezing of only a small portion of all the available CO2 is able to pump the energy released through adiabatic expansion, thus completely inhibiting the condensation of water vapour found in air packages adjacent to the gas volume gushing out of the Bottleneck.
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unveiling co2 heterogeneous freezing plumes during champagne cork popping
Scientific Reports, 2017Co-Authors: Gerard Ligerbelair, Daniel Cordier, Jacques Honvault, Clara CilindreAbstract:Cork popping from clear transparent bottles of champagne stored at different temperatures (namely, 6, 12, and 20 °C) was filmed through high-speed video imaging in the visible light spectrum. During the cork popping process, a plume mainly composed of gaseous CO2 with traces of water vapour freely expands out of the Bottleneck through ambient air. Most interestingly, for the bottles stored at 20 °C, the characteristic grey-white cloud of fog classically observed above the Bottlenecks of champagne stored at lower temperatures simply disappeared. It is replaced by a more evanescent plume, surprisingly blue, starting from the Bottleneck. We suggest that heterogeneous freezing of CO2 occurs on ice water clusters homogeneously nucleated in the Bottlenecks, depending on the saturation ratio experienced by gas-phase CO2 after adiabatic expansion (indeed highly bottle temperature dependent). Moreover, and as observed for the bottles stored at 20 °C, we show that the freezing of only a small portion of all the available CO2 is able to pump the energy released through adiabatic expansion, thus completely inhibiting the condensation of water vapour found in air packages adjacent to the gas volume gushing out of the Bottleneck.
Gregory Alvord - One of the best experts on this subject based on the ideXlab platform.
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impact of a population Bottleneck on symmetry and genetic diversity in the northern elephant seal
Journal of Evolutionary Biology, 2002Co-Authors: A. Rus Hoelzel, B Le J Boeuf, Claudio Campagna, Robert C Fleischer, Gregory AlvordAbstract:The northern elephant seal (NES) suffered a severe population Bottleneck towards the end of the nineteenth century. Theoretical expectations for the impact of population Bottlenecks include the loss of genetic diversity and a loss of fitness (e.g. through a disruption of developmental stability); however, there are few direct demonstrations in natural populations. Here, we report on the comparison of archive samples collected prior to and following the NES population Bottleneck. Measures of genetic diversity show a loss of variation consistent with expectations and suggest a strong disruption in the pattern of allele frequencies following the Bottleneck. Measures of bilateral characters show an increase in fluctuating asymmetry.
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impact of a population Bottleneck on symmetry and genetic diversity in the northern elephant seal
Journal of Evolutionary Biology, 2002Co-Authors: A. Rus Hoelzel, B Le J Boeuf, Claudio Campagna, Robert C Fleischer, Gregory AlvordAbstract:The northern elephant seal (NES) suffered a severe population Bottleneck towards the end of the nineteenth century. Theoretical expectations for the impact of population Bottlenecks include the loss of genetic diversity and a loss of fitness (e.g. through a disruption of developmental stability); however, there are few direct demonstrations in natural populations. Here, we report on the comparison of archive samples collected prior to and following the NES population Bottleneck. Measures of genetic diversity show a loss of variation consistent with expectations and suggest a strong disruption in the pattern of allele frequencies following the Bottleneck. Measures of bilateral characters show an increase in fluctuating asymmetry.
Robert C Fleischer - One of the best experts on this subject based on the ideXlab platform.
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impact of a population Bottleneck on symmetry and genetic diversity in the northern elephant seal
Journal of Evolutionary Biology, 2002Co-Authors: A. Rus Hoelzel, B Le J Boeuf, Claudio Campagna, Robert C Fleischer, Gregory AlvordAbstract:The northern elephant seal (NES) suffered a severe population Bottleneck towards the end of the nineteenth century. Theoretical expectations for the impact of population Bottlenecks include the loss of genetic diversity and a loss of fitness (e.g. through a disruption of developmental stability); however, there are few direct demonstrations in natural populations. Here, we report on the comparison of archive samples collected prior to and following the NES population Bottleneck. Measures of genetic diversity show a loss of variation consistent with expectations and suggest a strong disruption in the pattern of allele frequencies following the Bottleneck. Measures of bilateral characters show an increase in fluctuating asymmetry.
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impact of a population Bottleneck on symmetry and genetic diversity in the northern elephant seal
Journal of Evolutionary Biology, 2002Co-Authors: A. Rus Hoelzel, B Le J Boeuf, Claudio Campagna, Robert C Fleischer, Gregory AlvordAbstract:The northern elephant seal (NES) suffered a severe population Bottleneck towards the end of the nineteenth century. Theoretical expectations for the impact of population Bottlenecks include the loss of genetic diversity and a loss of fitness (e.g. through a disruption of developmental stability); however, there are few direct demonstrations in natural populations. Here, we report on the comparison of archive samples collected prior to and following the NES population Bottleneck. Measures of genetic diversity show a loss of variation consistent with expectations and suggest a strong disruption in the pattern of allele frequencies following the Bottleneck. Measures of bilateral characters show an increase in fluctuating asymmetry.
Hannah Blencowe - One of the best experts on this subject based on the ideXlab platform.
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kangaroo mother care a multi country analysis of health system Bottlenecks and potential solutions
BMC Pregnancy and Childbirth, 2015Co-Authors: Linda Vesel, Annemarie Bergh, Kate Kerber, Bina Valsangkar, Goldy Mazia, Sarah G Moxon, Hannah BlencoweAbstract:Preterm birth is now the leading cause of under-five child deaths worldwide with one million direct deaths plus approximately another million where preterm is a risk factor for neonatal deaths due to other causes. There is strong evidence that kangaroo mother care (KMC) reduces mortality among babies with birth weight <2000 g (mostly preterm). KMC involves continuous skin-to-skin contact, breastfeeding support, and promotion of early hospital discharge with follow-up. The World Health Organization has endorsed KMC for stabilised newborns in health facilities in both high-income and low-resource settings. The objectives of this paper are to: (1) use a 12-country analysis to explore health system Bottlenecks affecting the scale-up of KMC; (2) propose solutions to the most significant Bottlenecks; and (3) outline priority actions for scale-up. The Bottleneck analysis tool was applied in 12 countries in Africa and Asia as part of the Every Newborn Action Plan process. Country workshops involved technical experts to complete the survey tool, which is designed to synthesise and grade health system "Bottlenecks", factors that hinder the scale-up, of maternal-newborn intervention packages. We used quantitative and qualitative methods to analyse the Bottleneck data, combined with literature review, to present priority Bottlenecks and actions relevant to different health system building blocks for KMC. Marked differences were found in the perceived severity of health system Bottlenecks between Asian and African countries, with the former reporting more significant or very major Bottlenecks for KMC with respect to all the health system building blocks. Community ownership and health financing Bottlenecks were significant or very major Bottlenecks for KMC in both low and high mortality contexts, particularly in South Asia. Significant Bottlenecks were also reported for leadership and governance and health workforce building blocks. There are at least a dozen countries worldwide with national KMC programmes, and we identify three pathways to scale: (1) champion-led; (2) project-initiated; and (3) health systems designed. The combination of all three pathways may lead to more rapid scale-up. KMC has the potential to save lives, and change the face of facility-based newborn care, whilst empowering women to care for their preterm newborns.
Sarah G Moxon - One of the best experts on this subject based on the ideXlab platform.
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kangaroo mother care a multi country analysis of health system Bottlenecks and potential solutions
BMC Pregnancy and Childbirth, 2015Co-Authors: Linda Vesel, Annemarie Bergh, Kate Kerber, Bina Valsangkar, Goldy Mazia, Sarah G Moxon, Hannah BlencoweAbstract:Preterm birth is now the leading cause of under-five child deaths worldwide with one million direct deaths plus approximately another million where preterm is a risk factor for neonatal deaths due to other causes. There is strong evidence that kangaroo mother care (KMC) reduces mortality among babies with birth weight <2000 g (mostly preterm). KMC involves continuous skin-to-skin contact, breastfeeding support, and promotion of early hospital discharge with follow-up. The World Health Organization has endorsed KMC for stabilised newborns in health facilities in both high-income and low-resource settings. The objectives of this paper are to: (1) use a 12-country analysis to explore health system Bottlenecks affecting the scale-up of KMC; (2) propose solutions to the most significant Bottlenecks; and (3) outline priority actions for scale-up. The Bottleneck analysis tool was applied in 12 countries in Africa and Asia as part of the Every Newborn Action Plan process. Country workshops involved technical experts to complete the survey tool, which is designed to synthesise and grade health system "Bottlenecks", factors that hinder the scale-up, of maternal-newborn intervention packages. We used quantitative and qualitative methods to analyse the Bottleneck data, combined with literature review, to present priority Bottlenecks and actions relevant to different health system building blocks for KMC. Marked differences were found in the perceived severity of health system Bottlenecks between Asian and African countries, with the former reporting more significant or very major Bottlenecks for KMC with respect to all the health system building blocks. Community ownership and health financing Bottlenecks were significant or very major Bottlenecks for KMC in both low and high mortality contexts, particularly in South Asia. Significant Bottlenecks were also reported for leadership and governance and health workforce building blocks. There are at least a dozen countries worldwide with national KMC programmes, and we identify three pathways to scale: (1) champion-led; (2) project-initiated; and (3) health systems designed. The combination of all three pathways may lead to more rapid scale-up. KMC has the potential to save lives, and change the face of facility-based newborn care, whilst empowering women to care for their preterm newborns.
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basic newborn care and neonatal resuscitation a multi country analysis of health system Bottlenecks and potential solutions
BMC Pregnancy and Childbirth, 2015Co-Authors: Christabel Enweronularyea, Sarah G Moxon, Kim E Dickson, Aline Simenkapeu, Christabel Nyange, Susan Niermeyer, Howard L Sobel, Anne C C LeeAbstract:An estimated two-thirds of the world's 2.7 million newborn deaths could be prevented with quality care at birth and during the postnatal period. Basic Newborn Care (BNC) is part of the solution and includes hygienic birth and newborn care practices including cord care, thermal care, and early and exclusive breastfeeding. Timely provision of resuscitation if needed is also critical to newborn survival. This paper describes health system barriers to BNC and neonatal resuscitation and proposes solutions to scale up evidence-based strategies. The maternal and newborn Bottleneck analysis tool was applied by 12 countries in Africa and Asia as part of the Every Newborn Action Plan process. Country workshops engaged technical experts to complete the survey tool, which is designed to synthesise and grade health system "Bottlenecks" that hinder the scale up of maternal-newborn intervention packages. We used quantitative and qualitative methods to analyse the Bottleneck data, combined with literature review, to present priority Bottlenecks and actions relevant to different health system building blocks for BNC and neonatal resuscitation. Eleven of the 12 countries provided grading data. Overall, Bottlenecks were graded more severely for resuscitation. The most severely graded Bottlenecks for BNC were health workforce (8 of 11 countries), health financing (9 out of 11) and service delivery (7 out of 9); and for neonatal resuscitation, workforce (9 out of 10), essential commodities (9 out of 10) and service delivery (8 out of 10). Country teams from Africa graded Bottlenecks overall more severely. Improving workforce performance, availability of essential commodities, and well-integrated health service delivery were the key solutions proposed. BNC was perceived to have the least health system challenges among the seven maternal and newborn intervention packages assessed. Although neonatal resuscitation Bottlenecks were graded more severe than for BNC, similarities particularly in the workforce and service delivery building blocks highlight the inextricable link between the two interventions and the need to equip birth attendants with requisite skills and commodities to assess and care for every newborn. Solutions highlighted by country teams include ensuring more investment to improve workforce performance and distribution, especially numbers of skilled birth attendants, incentives for placement in challenging settings, and skills-based training particularly for neonatal resuscitation.
