99 research outputs found
Up, Down and Reciprocal: The Dynamics of Intergenerational Transfers, Family Structure and Health in a Low-Income Context
In the absence of well-functioning public transfer systems and safety nets, the family acts as the key provider of income and support through the intergenerational redistribution of resources. In this paper we use micro-level longitudinal data and a mix of methodologies to document the lifecycle patterns of financial transfers in a rural, sub-Saharan African population. Underneath a well-established age-pattern of intergenerational transfers in which transfer patterns change according to broad stages of the economic life cycle, our analyses document significant heterogeneity and fluidity: Intergenerational transfers are variable and reverse their direction, with individuals moving between the provider and recipient states repeatedly across their life course and within each major stage of the life-cycle. Contrary to common perceptions about family transfers ameliorating short-term shocks, transfers in our analyses are driven primarily by demographic factors such as changes in health, household size, and household composition, rather than short-term events. Overall our analyses suggest that the role of transfers in this rural sub-Saharan context is significantly more complex than suggested by theories and evidence on aggregate transfer patterns, and at the micro-level, intergenerational transfers encapsulate multiple functions ranging from direct exchange to old-age support in the absence of a public pension system
The Demography of Mental Health Among Mature Adults in a Low-Income High HIV-Prevalence Context
While a nascent body of research investigates the shift in sub-Saharan Africa\u27s (SSA\u27s) disease burden towards non-communicable diseases (NCDs), very few studies have investigated mental health, specifically depression and anxiety (DA), in SSA. Using the 2012--13 Malawi Longitudinal Study of Families and Health (MLSFH), this paper provides a first picture of the demography of DA among mature adults (= persons aged 45+) in a low-income high HIV-prevalence context. DA are more frequent among women than men, and individuals are often affected by both. DA are associated with adverse outcomes, such as less nutrition intake and reduced work efforts. DA also increase substantially with age for both females and males, and mature adults can expect to spend a substantial fraction of their remaining life time---for instance, 52% for a 55 year old woman---affected by DA. The positive age-gradients of DA are not due to cohort effects, and they are in sharp contrast to the age pattern of mental health that have been shown in high-income contexts where older individuals often experience lower levels of DA and better subjective well-being than middle-aged individuals. While socioeconomic and risk/uncertainty-related stressors are strongly associated with DA, they do not explain the positive age gradients and gender gap in DA. Stressors related to physical health, however, do. Hence, our analyses suggest that the general decline of physical strength and health with age, as is indicated by hand grip strength, and the interference of poor physical health with daily activities, are key drivers of the rise of DA with age among mature adults
Cognitive Health among Older Adults: Evidence from Rural Sub-Saharan Africa
Cognitive health is an important dimension of well-being in older ages, but few studies have investigated cognitive health in sub-Saharan Africa’s (SSA) growing population of mature adults (= persons age 45+). We use data from the Malawi Longitudinal Study of Families and Health (MLSFH) to document the age and gender patterns of cognitive health, the contextual and life-course correlates of poor cognitive health, and the understudied linkages between cognitive and physical/mental well-being. Surprisingly, the age-pattern of decline in cognitive health for both men and women is similar to that observed in the U.S. We also find that women have substantially worse cognitive health than men, and experience a steeper decline of cognitive ability with age. Strong social ties and exposure to socially complex environments are associated with higher cognitive health, as is higher socioeconomic status. Poor cognitive health is associated with adverse social and economic well-being outcomes such as less nutrition intake, lower income, and reduced work efforts even in this subsistence agriculture context. Lower levels of cognitive health are also strongly associated with increased levels of depression and anxiety, and are associated with worse physical health measured through both self-reports and physical performance
The Mature Adults Cohort of the Malawi Longitudinal Study of Families and Health (MLSFH-MAC)
Cohort purpose: The Mature Adults Cohort of the Malawi Longitudinal Study of Families and Health (MLSFH-MAC) contributes to global aging studies by providing a rare opportunity to study the processes of individual and population aging, the public health and social challenges associated with aging and the coincident shifts in disease burdens, in a low-income, high HIV prevalence, sub-Saharan African (SSA) context.
Design and Measures: The MLSFH-MAC is a population-based cohort study of mature adults aged 45 years and older living in rural communities in three districts in Malawi (Mchinji, Balaka and Rumphi). Initial enrollment at baseline is 1,266 individuals in 2012. MLSFH-MAC follow-ups were in 2013, 2017, and 2018. Survey instruments cover aging-related topics such as cognitive and mental health, NCDs and related health literacy, subjective survival expectations, measured biomarkers including HIV, grip strength, hypertension, fasting glucose, BMI, a broad range of individual- and household-level social and economic information, a 2018 qualitative survey of mature adults and community officials, 2019 surveys of village heads, health care facilities and health care providers in the MLSFH-MAC study areas.
Unique features: MLSFH-MAC is a data resource that covers 20 years of the life course of cohort members and provides a wealth of information unprecedented for aging studies in a low-income SSA context that broadly represents the socioeconomic environment of millions of individuals in south-eastern Africa. Among these are the longitudinal population-based data on depression and anxiety using clinically-validated instruments. MLSFH-MAC is also vanguard in measuring longitudinal changes in cognitive health among older individuals in SSA. Complemented by contextual and qualitative information, the extensive MLSFH-MAC data facilitate a life-course perspective on aging that reflects the dynamic and distinct settings in which people reach older ages in SSA LICs. Across many domains, MLSFH-MAC also allows for comparative research with global aging studies through harmonized measures and instruments.
Collaboration and data access: Public-use version of the 2012 (baseline) MLSFH-MAC data can be requested at http://www.malawi.pop.upenn.edu. Sharing of additional MLSFH-MAC data is currently possible as part of collaborative research projects (if not overlapping with ongoing research projects, and subject to a Data Use Agreement)
Frailty and physical performance in the context of extreme poverty:a population-based study of older adults in rural Burkina Faso
Background: Little is known about the prevalence of frailty and about normal values for physical performance among older individuals in low-income countries, in particular those in sub-Saharan Africa. We describe the prevalence of phenotypic frailty, and values and correlates of several physical performance measures in a cohort of middle-aged and older people living in rural Burkina Faso, one of the world's poorest communities.
Methods: We analysed data collected from participants aged over 40 in Nouna district, Burkina Faso. We measured handgrip strength, four metre walk speed, chair rise time, and derived the Fried frailty score based on grip strength, gait speed, body mass index, self-reported exhaustion, and physical activity. Frailty and physical performance indicators were then correlated with health and sociodemographic variables including comorbid disease, marital status, age, sex, wealth and activity impairment.
Results: Our sample included 2973 individuals (1503 women), mean age 54 years. 1207 (43%) were categorised as non-frail, 1324 (44%) as prefrail, 212 (7%) as frail, and 167 (6%) were unable to complete all five frailty score components. Lower grip strength, longer chair stand time, lower walk speed and prevalence of frailty rose with age. Frailty was more common in women than men (8% vs 6%, p=0.01) except in those aged 80 and over. Frailty was strongly associated with impairment of activities of daily living and with lower wealth, being widowed, diabetes mellitus, hypertension, and self-reported diagnoses of tuberculosis or heart disease. With the exception of grip strength, which was higher in women than prior international normative values, women had greater deficits than men in physical performance.
Conclusions: Phenotypic frailty and impaired physical performance were associated as expected with female sex, co-morbidities, increasing age and impaired activities of daily living. These results support the use of frailty measurements for classification of ageing related syndromes in this setting.GH is supported by a Wellcome Trust/Royal Society Sir Henry Dale fellowship, award number 210479/Z/18/Z. Support for the CRSN Heidelberg Aging Study and for TB was provided by the Alexander von Humboldt Foundation through the Alexander von Humboldt Professor award to Till Bärnighausen, funded by the German Federal Ministry of Education and Research. JMG is supported by Grant Number T32 AI007433 from the National Institute of Allergy and Infectious Diseases. The contents of this study are solely the responsibility of the authors and do not necessarily represent the official views of the NIH. MDW acknowledges support from the NIHR Newcastle Biomedical Research Centre. CFP acknowledges support from the ANU Futures Scheme
Prevalence and correlates of frailty in an older rural African population:findings from the HAALSI cohort study
Background: Frailty is a key predictor of death and dependency, yet little is known about frailty in sub-Saharan Africa despite rapid population ageing. We describe the prevalence and correlates of phenotypic frailty using data from the Health and Aging in Africa: Longitudinal Studies of an INDEPTH Community cohort. Methods: We analysed data from rural South Africans aged 40 and over. We used low grip strength, slow gait speed, low body mass index, and combinations of self-reported exhaustion, decline in health, low physical activity and high self-reported sedentariness to derive nine variants of a phenotypic frailty score. Each frailty category was compared with self-reported health, subjective wellbeing, impairment in activities of daily living and the presence of multimorbidity. Cox regression analyses were used to compare subsequent all-cause mortality for non-frail (score 0), pre-frail (score 1–2) and frail participants (score 3+). Results: Five thousand fifty nine individuals (mean age 61.7 years, 2714 female) were included in the analyses. The nine frailty score variants yielded a range of frailty prevalences (5.4% to 13.2%). For all variants, rates were higher in women than in men, and rose steeply with age. Frailty was associated with worse subjective wellbeing, and worse self-reported health. Both prefrailty and frailty were associated with a higher risk of death during a mean 17 month follow up for all score variants (hazard ratios 1.29 to 2.41 for pre-frail vs non-frail; hazard ratios 2.65 to 8.91 for frail vs non-frail). Conclusions: Phenotypic frailty could be measured in this older South African population, and was associated with worse health, wellbeing and earlier death
Incomplete gastric metaplasia in children with insulin-dependent diabetes mellitus and celiac disease. An ultrastructural study
BACKGROUND: The association of insulin-dependent diabetes mellitus (IDDM) and celiac disease (CD) has been widely reported in children but the relationship between the two conditions is incompletely understood. Moreover, specific studies on intestinal biopsies of patients with the association of the two diseases are still lacking. METHODS: We studied the ultrastructure of the duodenal mucosa in 12 patients with both IDDM and CD. RESULTS: All patients had either total or partial atrophy of duodenal mucosa. In seven subjects, an accumulation of electrondense granules in the apical cytoplasm of groups of enterocytes was found. In four of them, a double population of granules existed (mean diameter: 400-800 nm and 100-200 nm respectively) showing a biphasic pattern. In the other three patients, only smaller granules (100- 200 nm) were found in the enterocytes. CONCLUSIONS: The present work suggests that patients with IDDM/CD may represent a subgroup in the context of the CD population. Intestinal biopsies of such individuals often show accumulation of electrondense granules in the apical cytoplasm of enterocytes that can be interpreted as incomplete gastric metaplasia
Microwave sensor system for continuous monitoring of adhesive curing processes
A microwave sensor system has been developed for monitoring adhesive curing processes. The system provides continuous, real-time information about the curing progress without interfering with the reaction. An open-coaxial resonator is used as the sensor head, and measurements of its resonance frequency and quality factor are performed during cure to follow the reaction progress. Additionally, the system provides other interesting parameters such as reaction rate or cure time. The adhesive dielectric properties can also be computed off-line, which gives additional information about the process. The results given by the system correlate very well with conventional measurement techniques such as differential scanning calorimetry, combining accuracy and rate with simplicity and an affordable cost. © 2012 IOP Publishing Ltd.The authors thank Rut Benavente Martinez for her assistance in the DSC experiments. The contract of BG-B is financed by the Ministry of Science and Innovation of Spain, through the 'Torres Quevedo' Sub-programme, which is also co-financed by the European Social Fund (ESF). This work has been financed by the Ministry of Science and Innovation of Spain through the project MONIDIEL (TEC2008-04109).GarcÃa Baños, B.; Catalá Civera, JM.; Penaranda-Foix, FL.; Canós MarÃn, AJ.; Sahuquillo Navarro, O. (2012). Microwave sensor system for continuous monitoring of adhesive curing processes. Measurement Science and Technology. 23(3). https://doi.org/10.1088/0957-0233/23/3/035101S233Jost, M., & Sernek, M. (2008). Shear strength development of the phenol–formaldehyde adhesive bond during cure. Wood Science and Technology, 43(1-2), 153-166. doi:10.1007/s00226-008-0217-2Costa, M. L., Botelho, E. C., Paiva, J. M. F. de, & Rezende, M. C. (2005). Characterization of cure of carbon/epoxy prepreg used in aerospace field. 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From Sea to Sea: Canada's Three Oceans of Biodiversity
Evaluating and understanding biodiversity in marine ecosystems are both necessary and challenging for conservation. This paper compiles and summarizes current knowledge of the diversity of marine taxa in Canada's three oceans while recognizing that this compilation is incomplete and will change in the future. That Canada has the longest coastline in the world and incorporates distinctly different biogeographic provinces and ecoregions (e.g., temperate through ice-covered areas) constrains this analysis. The taxonomic groups presented here include microbes, phytoplankton, macroalgae, zooplankton, benthic infauna, fishes, and marine mammals. The minimum number of species or taxa compiled here is 15,988 for the three Canadian oceans. However, this number clearly underestimates in several ways the total number of taxa present. First, there are significant gaps in the published literature. Second, the diversity of many habitats has not been compiled for all taxonomic groups (e.g., intertidal rocky shores, deep sea), and data compilations are based on short-term, directed research programs or longer-term monitoring activities with limited spatial resolution. Third, the biodiversity of large organisms is well known, but this is not true of smaller organisms. Finally, the greatest constraint on this summary is the willingness and capacity of those who collected the data to make it available to those interested in biodiversity meta-analyses. Confirmation of identities and intercomparison of studies are also constrained by the disturbing rate of decline in the number of taxonomists and systematists specializing on marine taxa in Canada. This decline is mostly the result of retirements of current specialists and to a lack of training and employment opportunities for new ones. Considering the difficulties encountered in compiling an overview of biogeographic data and the diversity of species or taxa in Canada's three oceans, this synthesis is intended to serve as a biodiversity baseline for a new program on marine biodiversity, the Canadian Healthy Ocean Network. A major effort needs to be undertaken to establish a complete baseline of Canadian marine biodiversity of all taxonomic groups, especially if we are to understand and conserve this part of Canada's natural heritage
Ubiquitous molecular substrates for associative learning and activity-dependent neuronal facilitation.
Recent evidence suggests that many of the molecular cascades and substrates that contribute to learning-related forms of neuronal plasticity may be conserved across ostensibly disparate model systems. Notably, the facilitation of neuronal excitability and synaptic transmission that contribute to associative learning in Aplysia and Hermissenda, as well as associative LTP in hippocampal CA1 cells, all require (or are enhanced by) the convergence of a transient elevation in intracellular Ca2+ with transmitter binding to metabotropic cell-surface receptors. This temporal convergence of Ca2+ and G-protein-stimulated second-messenger cascades synergistically stimulates several classes of serine/threonine protein kinases, which in turn modulate receptor function or cell excitability through the phosphorylation of ion channels. We present a summary of the biophysical and molecular constituents of neuronal and synaptic facilitation in each of these three model systems. Although specific components of the underlying molecular cascades differ across these three systems, fundamental aspects of these cascades are widely conserved, leading to the conclusion that the conceptual semblance of these superficially disparate systems is far greater than is generally acknowledged. We suggest that the elucidation of mechanistic similarities between different systems will ultimately fulfill the goal of the model systems approach, that is, the description of critical and ubiquitous features of neuronal and synaptic events that contribute to memory induction
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