title: Evolution of the axial magnetic field in solar filament channels

authors: Litvinenko, Yuri E.

subjects: magnetic reconnection

abstract: Formation of solar filament channels by photospheric magnetic reconnection is considered. A magnetohydrodynamic model for magnetic merging, driven by converging convective motions in the photosphere, is presented. Evolution of the axial magnetic field in a channel is analyzed. An exact time-dependent analytical solution for the field profile in a steady stagnation-point flow is derived. The maximum magnetic field in the channel is determined, and its dependence on the reconnection inflow speed is discussed. The quantitative results show that the maximum axial magnetic field in a forming channel is an indicator of the photospheric reconnection rate, in agreement with recent solar observations and laboratory experiments.

text: Evolution of the axial magnetic field in solar filament channels Formation of solar filament channels by photospheric magnetic reconnection is considered. A magnetohydrodynamic model for magnetic merging, driven by converging convective motions in the photosphere, is presented. Evolution of the axial magnetic field in a channel is analyzed. An exact time-dependent analytical solution for the field profile in a steady stagnation-point flow is derived. The maximum magnetic field in the channel is determined, and its dependence on the reconnection inflow speed is discussed. The quantitative results show that the maximum axial magnetic field in a forming channel is an indicator of the photospheric reconnection rate, in agreement with recent solar observations and laboratory experiments.

year: 2010

title: Underlying and state-level contextual determinants of early childhood mortality in Nigeria

authors: Umesi, Love Ugonna

subjects: Under-five mortality

abstract: Early childhood mortality has remained stubbornly high in Nigeria, even compared with other sub-Saharan African countries. Tragically, one in every eight children in Nigeria die before their fifth birthday and more than half of those deaths are from preventable causes. Nigeria’s high under-five mortality is indicative of the poor quality of health for the average Nigerian. Sub-national under-five mortality is even more worrisome given the vast differences in survivorship, ranging from a high of 252 deaths per 1,000 live births in Kebbi state (North West) to a low of 30 deaths per 1,000 live births in Ogun state (South West). These sub-national disparities highlight the importance of accounting for the hitherto unexplored impacts of community level background characteristics.

This study conducted an in-depth analysis of the determinants of under-five mortality in Nigeria from 2008 to 2018, focusing on the direct and indirect impacts of community context and socio-economic change. This approach is novel as most studies of under-five mortality in Africa have focused on individual and household factors. Using data from the Nigeria Demographic and Health Survey (NDHS), I examined persistent inequalities in under five-mortality between states and within socio-economic groups. Analyses were carried out in three stages. Trends and patterns of under-five deaths in Nigeria, alongside individual/household level factors associated with it was done using 2008, 2013, and 2018 NDHS. Then data from 2018 NDHS was used to explore child survival function, incidence rates of death, and determinants of under-five mortality using Cox proportional hazards regression. While still focusing on the 2018 NDHS, the study was further extended to a multilevel analysis to investigate the community-level contextual factors associated with under-five mortality in Nigeria using mixed-effects logistics regression and Cox proportional hazards regression with random effects.

The results showed that under-five mortality in Nigeria was persistently high over the focal period. Generally, the hazard rate of death was highest at birth and in the first month of life. The study found that the composition of the community at the individual/household level, together with community level contextual factors were predisposing factors to under-five mortality. Hence, residence in different community context in Nigeria appear to significantly influence variations in under-five mortality between and across communities, geo-political zones, and states. More specifically, the proportion of hospital deliveries and proportion of children fully immunized in the community influenced early childhood survival. Child survival estimates and incidence of death also confirmed that under-five children in the North East and North West had lower survival probabilities than their counterparts in other geo-political zones. The findings suggest that effective measures to improve early childhood survival should look further than individual and household-level interventions to also address pertinent community contextual factors.

text: Underlying and state-level contextual determinants of early childhood mortality in Nigeria Early childhood mortality has remained stubbornly high in Nigeria, even compared with other sub-Saharan African countries. Tragically, one in every eight children in Nigeria die before their fifth birthday and more than half of those deaths are from preventable causes. Nigeria’s high under-five mortality is indicative of the poor quality of health for the average Nigerian. Sub-national under-five mortality is even more worrisome given the vast differences in survivorship, ranging from a high of 252 deaths per 1,000 live births in Kebbi state (North West) to a low of 30 deaths per 1,000 live births in Ogun state (South West). These sub-national disparities highlight the importance of accounting for the hitherto unexplored impacts of community level background characteristics.

This study conducted an in-depth analysis of the determinants of under-five mortality in Nigeria from 2008 to 2018, focusing on the direct and indirect impacts of community context and socio-economic change. This approach is novel as most studies of under-five mortality in Africa have focused on individual and household factors. Using data from the Nigeria Demographic and Health Survey (NDHS), I examined persistent inequalities in under five-mortality between states and within socio-economic groups. Analyses were carried out in three stages. Trends and patterns of under-five deaths in Nigeria, alongside individual/household level factors associated with it was done using 2008, 2013, and 2018 NDHS. Then data from 2018 NDHS was used to explore child survival function, incidence rates of death, and determinants of under-five mortality using Cox proportional hazards regression. While still focusing on the 2018 NDHS, the study was further extended to a multilevel analysis to investigate the community-level contextual factors associated with under-five mortality in Nigeria using mixed-effects logistics regression and Cox proportional hazards regression with random effects.

The results showed that under-five mortality in Nigeria was persistently high over the focal period. Generally, the hazard rate of death was highest at birth and in the first month of life. The study found that the composition of the community at the individual/household level, together with community level contextual factors were predisposing factors to under-five mortality. Hence, residence in different community context in Nigeria appear to significantly influence variations in under-five mortality between and across communities, geo-political zones, and states. More specifically, the proportion of hospital deliveries and proportion of children fully immunized in the community influenced early childhood survival. Child survival estimates and incidence of death also confirmed that under-five children in the North East and North West had lower survival probabilities than their counterparts in other geo-political zones. The findings suggest that effective measures to improve early childhood survival should look further than individual and household-level interventions to also address pertinent community contextual factors.

year: 2023

title: A discursive analysis of Maori in sexual and reproductive health policy

authors: Green, Jane Alison

subjects: Maori

abstract: No abstract provided

text: A discursive analysis of Maori in sexual and reproductive health policy No abstract provided

year: 2011