4,712 research outputs found

    Mortality, work and migration: a consideration of age-specific mortality from tuberculosis in Scotland, 1861-1901

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    This paper provides an examination into some of the most enduring debates regarding tuberculosis mortality during the nineteenth century: those related to gender, geographic and temporal variations. We use populations reconstructed from individual census and civil register data for the period 1861 to 1901, comparing a growing urban area with a declining rural area, both with around 20,000 inhabitants in 1861. Our analysis shows that among young adults tuberculosis was linked to excess female mortality in the urban area and excess male mortality in the rural area. We demonstrate that in the town textile workers of both genders had particularly high mortality from tuberculosis, and that the only reason for higher overall female mortality was the predominance of young women in the textile labour force. We show that the age and gender-specific pattern of mortality in the rural area is consistent with higher male than female out-migration together with return migration of those who had contracted the disease elsewhere and needed care during their lengthy illness. We argue that the observed patterns are difficult to reconcile with the 'bargaining-nutrition' account of gendered patterns in tuberculosis mortality, and that they provide little support for nutrition as a key influence on the disease. However, our findings do reinforce Andrew Hinde's recent (2015) argument that geographical patterns in sex-specific tuberculosis mortality rates were largely determined by migration patterns, and we discuss the implications of this for our understanding of the decline of the disease over the late nineteenth century.This work was supported by the Economic and Social Research Council, RES-000-23-0128, ‘Determining the demography of Victorian Scotland through record linkage’ (to Dr Alice Reid, University of Cambridge); Wellcome Trust Award, 082200/Z/07/Z, ‘Doctors, deaths, diagnoses and data: a comparative study of the medical certification of cause of death in nineteenth century Scotland (to Prof. Richard Smith, University of Cambridge); and Wellcome Trust Award 103322, 'Migration, Mortality and Medicalisation: investigating the long-run epidemiological consequences of urbanisation 1600 - 1945' (to Prof. Richard Smith, University of Cambridge)

    Biosocial life-course factors associated with women's early marriage in rural India: The prospective longitudinal Pune Maternal Nutrition Study

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    Objectives: By convention, women's early marriage is considered a sociocultural decision sensitive to factors acting during adolescence such as poverty, early menarche, and less education. Few studies have examined broader risk factors in the natal household prior to marriage. We investigated whether biosocial markers of parental investment through the daughters' life-course were associated with early marriage risk in rural India. We used an evolutionary perspective to interpret our findings. / Materials and Methods: A prospective cohort recruited mothers at preconception. Children were followed from birth to age 21 years. Multivariable logistic regression models estimated odds ratios of marrying early (<19 years) associated first with wealth, age at menarche and education, and then with broader markers of maternal phenotype, natal household characteristics, and girls' growth trajectories. Models adjusted for confounders. / Results: Of 305 girls, 71 (23%) had married early. Early married girls showed different patterns of growth compared to unmarried girls. Neither poverty nor early menarche predicted early marriage. Girls' non-completion of lower secondary school predicted early marriage, explaining 19% of the variance. Independent of girls' lower schooling, nuclear household, low paternal education, shorter gestation, and girls' poor infant weight gain were associated with marrying early, explaining in combination 35% of the variance. / Discussion: Early marriage reflects “future discounting,” where reduced parental investment in daughters' somatic and educational capital from early in her life favors an earlier transition to the life-course stage when reproduction can occur. Interventions initiated in adolescence may occur too late in the life-course to effectively delay women's marriage

    Adjuvant Therapy for Stage IB Germ Cell Tumors: One versus Two Cycles of BEP.

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    Testicular germ cell tumours are the commonest tumours of young men and are broadly managed either as pure seminomas or as 'nonseminomas'. The management of Stage 1 nonseminomatous germ cell tumours (NSGCTs), beyond surgical removal of the primary tumour at orchidectomy, is somewhat controversial. Cancer-specific survival rates in these patients are in the order of 99% regardless of whether surveillance, retroperitoneal lymph node dissection, or adjuvant chemotherapy is employed. However, the toxicities of these treatment modalities differ. Undertreating those destined to relapse exposes them to the potentially significant toxicities of 3-4 cycles of bleomycin, etoposide, and cisplatin (BEP) chemotherapy. Conversely, giving adjuvant chemotherapy to all patients following orchidectomy results in overtreatment of a significant proportion. Therefore, the challenge lies in delineating the patient population who require adjuvant chemotherapy and in determining how much chemotherapy to give to adequately reduce relapse risk. This chapter reviews the factors to be considered when adopting a risk-adapted strategy for giving adjuvant chemotherapy in Stage 1B NSGCT sand discusses the data regarding the number of BEP cycles to administer

    A Stochastic Approach to Shortcut Bridging in Programmable Matter

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    In a self-organizing particle system, an abstraction of programmable matter, simple computational elements called particles with limited memory and communication self-organize to solve system-wide problems of movement, coordination, and configuration. In this paper, we consider a stochastic, distributed, local, asynchronous algorithm for "shortcut bridging", in which particles self-assemble bridges over gaps that simultaneously balance minimizing the length and cost of the bridge. Army ants of the genus Eciton have been observed exhibiting a similar behavior in their foraging trails, dynamically adjusting their bridges to satisfy an efficiency trade-off using local interactions. Using techniques from Markov chain analysis, we rigorously analyze our algorithm, show it achieves a near-optimal balance between the competing factors of path length and bridge cost, and prove that it exhibits a dependence on the angle of the gap being "shortcut" similar to that of the ant bridges. We also present simulation results that qualitatively compare our algorithm with the army ant bridging behavior. Our work gives a plausible explanation of how convergence to globally optimal configurations can be achieved via local interactions by simple organisms (e.g., ants) with some limited computational power and access to random bits. The proposed algorithm also demonstrates the robustness of the stochastic approach to algorithms for programmable matter, as it is a surprisingly simple extension of our previous stochastic algorithm for compression.Comment: Published in Proc. of DNA23: DNA Computing and Molecular Programming - 23rd International Conference, 2017. An updated journal version will appear in the DNA23 Special Issue of Natural Computin

    Independent associations of women's age at marriage and first pregnancy with their height in rural lowland Nepal

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    OBJECTIVES: In many South Asian communities, the majority of women are married during adolescence and reproduce before 20 years. Early reproduction may adversely affect maternal nutrition and linear growth, however whether early marriage has similar effects is unknown. Shorter women might also be preferentially chosen for earlier marriage. We hypothesized that early marriage and early pregnancy may each be associated with women's shorter height, independent of any selection effects. MATERIALS AND METHODS: We analyzed cross-sectional data on 7,146 women aged 20-30 years from rural lowland Nepal. Linear regression models tested associations of early marriage and early reproduction with height, adjusting for women's education and husbands' characteristics (education and wealth) that might index preferential selection of short young women for marriage. RESULTS: Median ages at marriage and first pregnancy were 15 and 18 years, respectively, with 20% pregnant <16 years. Both early marriage and early pregnancy were independently associated with shorter stature, accounting for a decrement of 1.4 cm, which decreased to 1 cm after adjusting for women's education. Effects of early marriage and reproduction persisted after adjusting for the tendency of poorer and less educated men to marry young and short women, indicating a role for social selection. DISCUSSION: The decrements in height associated with early marriage and reproduction are indicative of broader adverse effects on maternal metabolism during a "critical period" of growth and maturation in the life-course of women. Although the magnitudes of effect are relatively small, they affect large numbers of women in this population

    The Accelerations of Stars Orbiting the Milky Way's Central Black Hole

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    Recent measurements, of the velocities of stars near the center of the Milky Way have provided the strongest evidence for the presence of a supermassive black hole in a galaxy, but the observational uncertainties poorly constrain many of the properties of the black hole. Determining the accelerations of stars in their orbits around the center provides much more precise information about the position and mass of the black hole. Here we report measurements of the accelerations for three stars located ~0.005 pc from the central radio source Sgr A*; these accelerations are comparable to those experienced by the Earth as it orbits the Sun. These data increase the inferred minimum mass density in the central region of the Galaxy by an order of magnitude relative to previous results and localized the dark mass to within 0.05 +- 0.04 arcsec of the nominal position of Sgr A*. In addition, the orbital period of one of the observed stars could be as short as 15 years, allowing us the opportunity in the near future to observe an entire period.Comment: To appear in September 21 2000 issue of Natur

    Multiple roles for endothelin in melanocyte development: Regulation of progenitor number and stimulation of differentiation

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    Melanocytes in the skin are derived from the embryonic neural crest, Recently, mutations in endothelin 3 and the endothelin receptor B genes have been shown to result in gross pigment defects, indicating that this signalling pathway is required for melanocyte development. We have examined the effects of endothelins on melanocyte progenitors in cultures of mouse neural crest. Firstly, they stimulate an increase in progenitor number and act synergistically with another factor, Steel factor, in the survival and proliferation of the progenitors. These findings are consistent with findings from mice with natural mutations in the endothelin receptor B gene, which show an early loss of melanocyte progenitors. Secondly, endothelins induce differentiation of the progenitors into fully mature pigmented melanocytes. This finding is consistent with the expression of endothelins in the skin of mice at the initiation of pigmentation. The melanocytes generated in endothelin-treated cultures also become responsive to alpha melanocyte-stimulating hormone, which then acts to regulate the activity of the pigmentation pathway. These findings indicate two key roles for endothelin in melanocyte development: regulation of expansion of the progenitor pool and differentiation of progenitors into mature melanocytes

    Associations of extracurricular physical activity patterns and body composition components in a multi-ethnic population of UK children (the Size and Lung Function in Children study): a multilevel modelling analysis.

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    BACKGROUND: Body Mass Index (BMI) is a common outcome when assessing associations between childhood overweight and obesity and physical activity patterns. However, the fat and fat-free components of BMI, measured by the Fat Mass Index (FMI) and Fat-Free Mass Index (FFMI), may show contrasting associations with physical activity, while ethnic groups may vary in both physical activity patterns and body composition. Body composition must therefore be evaluated when assessing the associations between childhood overweight and obesity and physical activity in multi-ethnic populations. METHODS: This cross-sectional study investigated associations of BMI, FMI and FFMI z-scores with extracurricular physical activity for 2171 London primary schoolchildren (aged 5-11 years) of black, South Asian and white/other ethnicity. Multilevel mixed-effects ordered logistic modelling was used, adjusting for age, sex and family and neighbourhood socioeconomic status as potential confounders. RESULTS: Controlling for ethnicity and individual, family and neighbourhood socioeconomic confounders, actively commuting children had significantly lower Odds Ratios for being in high BMI (Odds Ratio (OR) = 0.678; 95 % Confidence Interval (CI) = 0.531 - 0.865; p - value = 0.002) and FMI z-score groups (OR = 0.679; 95 % CI = 0.499 - 0.922; p = 0.013), but not FFMI z-score groups, than passive commuters. Children doing sports less than once a week had lower Odds Ratios for being in high BMI (OR = 0.435; 95 % CI = 0.236 - 0.802; p = 0.008) and FFMI (OR = 0.455; 95 % CI = 0.214 - 0.969; p = .041) z-score categories compared to daily active children. Differences in FMI between groups did not reach the significance threshold. A trend towards statistical significance was obtained whereby children's complete inactivity was associated with higher odds for being in higher BMI (OR = 2.222 : 95 % CI = 0.977 - 5.052; p = .057) and FMI z-score groups (OR = 2.485 : 95 % CI = 0.961 - 6.429; p = .060). FFMI z-scores did not show a similar trend with complete inactivity. CONCLUSIONS: Active commuting was objectively associated with lower adiposity, while more frequent extracurricular sports participation was correlated with greater fat-free mass accretion. These relationships were independent of ethnicity and individual, family or neighbourhood socioeconomic confounding factors
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