120 research outputs found

    Association of socioeconomic status change between infancy and adolescence, and blood pressure, in South African young adults: Birth to Twenty Cohort

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    ObjectiveSocial epidemiology models suggest that socioeconomic status (SES) mobility across the life course affects blood pressure. The aim of this study was to investigate the association between SES change between infancy and adolescence, and blood pressure, in young adults, and the impact of early growth on this relationship.SettingData for this study were obtained from a ‘Birth to Twenty’ cohort in Soweto, Johannesburg, in South Africa.ParticipantsThe study included 838 Black participants aged 18 years who had household SES measures in infancy and at adolescence, anthropometry at 0, 2, 4 and 18 years of age and blood pressure at the age of 18 years.MethodsWe computed SES change using asset-based household SES in infancy and during adolescence as an exposure variable, and blood pressure and hypertension status as outcomes. Multivariate linear and logistic regressions were used to investigate the associations between SES change from infancy to adolescence, and age, height and sex-specific blood pressure and hypertension prevalence after adjusting for confounders.ResultsCompared to a persistent low SES, an upward SES change from low to high SES tertile between infancy and adolescence was significantly associated with lower systolic blood pressure (SBP) at the age of 18 years (ÎČ=−4.85; 95% CI −8.22 to −1.48; p<0.01; r2=0.1804) after adjusting for SES in infancy, small-for-gestational-age (SGA) and weight gain. Associations between SES change and SBP were partly explained by weight gain between birth and the age of 18 years. There was no association between SES mobility and diastolic blood pressure, mean arterial pressure or hypertension status.ConclusionsOur study confirms that upward SES change has a protective effect on SBP by the time participants reach young adulthood. Socioeconomic policies and interventions that address inequality may have the potential to reduce cardiovascular disease burden related to BP in later life

    Women’s Situational Coping With Acquaintance Sexual Assault: Applying an Appraisal-Based Model

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    Drawing on theories of appraisal-based coping, the present study applied structural modeling to examine relationships among personal goal orientations, primary and secondary appraisals of acquaintance sexual assault, and women’s emotional and behavioral responses to it. Based on 415 college women’s reports of a sexual assault experience, the model shows both direct and indirect effects. Assertive, diplomatic, and immobilized responding were each predicted by a unique profile of appraisals and orientations; personal goal orientations and primary appraisals were completely mediated by secondary appraisals. Ways that these findings can facilitate self-protective coping in an acquaintance sexual assault situation, leading to the development of effective, well-tailored self-defense and resistance programs, are discussed

    Association of socioeconomic status change between infancy and adolescence and blood pressure in South African young adults: Birth to Twenty Cohort

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    OBJECTIVE. Social epidemiology models suggest that socioeconomic status (SES) mobility across the life course affects blood pressure. The aim of this study was to investigate the association between SES change between infancy and adolescence, and blood pressure, in young adults, and the impact of early growth on this relationship. SETTING. Data for this study were obtained from a ‘Birth to Twenty’ cohort in Soweto, Johannesburg, in South Africa. PARTICIPANTS. The study included 838 Black participants aged 18 years who had household SES measures in infancy and at adolescence, anthropometry at 0, 2, 4 and 18 years of age and blood pressure at the age of 18 years. METHODS. We computed SES change using asset-based household SES in infancy and during adolescence as an exposure variable, and blood pressure and hypertension status as outcomes. Multivariate linear and logistic regressions were used to investigate the associations between SES change from infancy to adolescence, and age, height and sex-specific blood pressure and hypertension prevalence after adjusting for confounders. RESULTS. Compared to a persistent low SES, an upward SES change from low to high SES tertile between infancy and adolescence was significantly associated with lower systolic blood pressure (SBP) at the age of 18 years (ÎČ=−4.85; 95% CI −8.22 to −1.48; p<0.01; r2=0.1804) after adjusting for SES in infancy, small-for-gestational-age (SGA) and weight gain. Associations between SES change and SBP were partly explained by weight gain between birth and the age of 18 years. There was no association between SES mobility and diastolic blood pressure, mean arterial pressure or hypertension status. CONCLUSIONS. Our study confirms that upward SES change has a protective effect on SBP by the time participants reach young adulthood. Socioeconomic policies and interventions that address inequality may have the potential to reduce cardiovascular disease burden related to BP in later life

    A comparison of the socio-economic determinants of growth retardation in South African and Filipino infants

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    Objective: To examine the association between household socio-economic status (SES) at birth and poor infant growth such as small for gestational age (SGA) and stunting across two different socio-cultural settings: South Africa and the Philippines. Design: Data were from two longitudinal birth cohorts, the Birth to Twenty (Bt20) study in South Africa and the Cebu Longitudinal Health and Nutrition Survey (CLHNS) in the Philippines. Subjects: Bt20 infants (n 2293 total; reduced to 758 (SGA), 450 (stunting 1 year) and 401 (stunting 2 years)) and CLHNS infants (n 2513 total; reduced to 2161 (SGA), 1820 (stunting 1 year) and 1710 (stunting 2 years)). Results: CLHNS infants were significantly more likely to be born SGA (20.9 v. 11.7%) and be stunted at 1 year (32.6 v. 8.7%) and 2 years (48.9 v. 21.1%) compared with Bt20 infants. Logistic regression analyses showed that SES (index) was a significant predictor of stunting at 1 and 2 years of age in the CLHNS cohort. SES (index or individual variables) was not a significant predictor of SGA in either cohort, or of stunting in the Bt20 cohort. Maternal education, ownership of a television and toilet facilities were all independent predictors of stunting in the CLHNS cohort. Conclusions: The social and economic milieu within the Philippines appears to place CLHNS infants at greater risk of being born SGA and being stunted compared with Bt20 infants. The present research highlights the importance of investigating the individual SES variables that predict infantile growth faltering, to identify the key areas for context-specific policy development and intervention

    A comparison of the socio-economic determinants of growth retardation in South African and Filipino infants

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    OBJECTIVE: To examine the association between household socio-economic status (SES) at birth and poor infant growth such as small for gestational age (SGA) and stunting across two different socio-cultural settings: South Africa and the Philippines. DESIGN: Data were from two longitudinal birth cohorts, the Birth to Twenty (Bt20) study in South Africa and the Cebu Longitudinal Health and Nutrition Survey (CLHNS) in the Philippines. SUBJECTS: Bt20 infants (n 2293 total; reduced to 758 (SGA), 450 (stunting 1 year) and 401 (stunting 2 years)) and CLHNS infants (n 2513 total; reduced to 2161 (SGA), 1820 (stunting 1 year) and 1710 (stunting 2 years)). RESULTS: CLHNS infants were significantly more likely to be born SGA (20·9 v. 11·7%) and be stunted at 1 year (32·6 v. 8·7%) and 2 years (48·9 v. 21·1%) compared with Bt20 infants. Logistic regression analyses showed that SES (index) was a significant predictor of stunting at 1 and 2 years of age in the CLHNS cohort. SES (index or individual variables) was not a significant predictor of SGA in either cohort, or of stunting in the Bt20 cohort. Maternal education, ownership of a television and toilet facilities were all independent predictors of stunting in the CLHNS cohort. CONCLUSIONS: The social and economic milieu within the Philippines appears to place CLHNS infants at greater risk of being born SGA and being stunted compared with Bt20 infants. The present research highlights the importance of investigating the individual SES variables that predict infantile growth faltering, to identify the key areas for context-specific policy development and intervention

    Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

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    Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets

    Attrition, physical integrity and insecticidal activity of long-lasting insecticidal nets in sub-Saharan Africa and modelling of their impact on vectorial capacity

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    Long-lasting insecticidal nets (LLINs) are the primary malaria prevention and control intervention in many parts of sub-Saharan Africa. While LLINs are expected to last at least 3 years under normal use conditions, they can lose effectiveness because they fall out of use, are discarded, repurposed, physically damaged, or lose insecticidal activity. The contributions of these different interrelated factors to durability of nets and their protection against malaria have been unclear.; Starting in 2009, LLIN durability studies were conducted in seven countries in Africa over 5 years. WHO-recommended measures of attrition, LLIN use, insecticidal activity, and physical integrity were recorded for eight different net brands. These data were combined with analyses of experimental hut data on feeding inhibition and killing effects of LLINs on both susceptible and pyrethroid resistant malaria vectors to estimate the protection against malaria transmission-in terms of vectorial capacity (VC)-provided by each net cohort over time. Impact on VC was then compared in hypothetical scenarios where one durability outcome measure was set at the best possible level while keeping the others at the observed levels.; There was more variability in decay of protection over time by country than by net brand for three measures of durability (ratios of variance components 4.6, 4.4, and 1.8 times for LLIN survival, use, and integrity, respectively). In some countries, LLIN attrition was slow, but use declined rapidly. Non-use of LLINs generally had more effect on LLIN impact on VC than did attrition, hole formation, or insecticide loss.; There is much more variation in LLIN durability among countries than among net brands. Low levels of use may have a larger impact on effectiveness than does variation in attrition or LLIN degradation. The estimated entomological effects of chemical decay are relatively small, with physical decay probably more important as a driver of attrition and non-use than as a direct cause of loss of effect. Efforts to maximize LLIN impact in operational settings should focus on increasing LLIN usage, including through improvements in LLIN physical integrity. Further research is needed to understand household decisions related to LLIN use, including the influence of net durability and the presence of other nets in the household

    Agronomic and Economic Performance Characteristics of Conventional and Low-External-Input Cropping Systems in the Central Corn Belt

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    We conducted a 9-ha field experiment near Boone, IA, to test the hypothesis that yield, weed suppression, and profit characteristics of low-external-input (LEI) cropping systems can match or exceed those of conventional systems. Over a 4-yr period, we compared a conventionally managed 2-yr rotation system {corn (Zea mays L.)/soybean [Glycine max (L.) Merr.]} with two LEI systems: a 3-yr corn/soybean/small grain + red clover (Trifolium pratense L.) rotation, and a 4-yr corn/soybean/small grain + alfalfa (Medicago sativa L.)/alfalfa rotation. Synthetic N fertilizer use was 59 and 74% lower in the 3- and 4-yr systems, respectively, than in the 2-yr system; similarly, herbicide use was reduced 76 and 82% in the 3- and 4-yr systems. Corn and soybean yields were as high or higher in the LEI systems as in the conventional system, and weed biomass in corn and soybean was low (≀4.2 g m−2) in all systems. Experimentally supplemented giant foxtail (Setaria faberi Herrm.) seed densities in the surface 20 cm of soil declined in all systems; supplemented velvetleaf (Abutilon theophrasti Medik.) seed densities declined in the 2- and 4-yr systems and remained unchanged in the 3-yr system. Without subsidy payments, net returns were highest for the 4-yr system (540ha−1yr−1),lowestforthe3−yrsystem(540 ha−1 yr−1), lowest for the 3-yr system (475 ha−1 yr−1), and intermediate for the 2-yr system ($504 ha−1 yr−1). With subsidies, differences among systems in net returns were smaller, as subsidies favored the 2-yr system, but rank order of the systems was maintained
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