Partitioning the effects of secular trend and ageing on adult stature

A group of 16 captive-born hairy-faced, white-lipped, black-mantled tamarins, Saguinus nigricollis, were observed from birth to maturity. The data for the parameters, body weight, head-body length, right foot length and dental eruption age was recorded at monthly intervals. Linear growth was complete at approximately 12 months of age. Body weight reached the level of the wild-caught parents at 16 to 17 months of age. Deciduous dentition was complete at eight weeks of age and all permanent teeth were present by 41 weeks of age. While this sampling is too small for statistical verification, the data provides guidelines on the parameters recorded.     

The effects of aging and secular trend on adult stature in rural western Ireland

Cross-sectional data, consisting of anthropometric measurements for 347 adult males and 261 adult females in western Ireland measured during the 1930s, were used to determine the effects of aging and secular change upon stature. Estimates of statural loss due to aging were obtained using partial regression of stature on age while controlling for subischial length, and regression of the difference between observed stature and maximum predicted stature on age. Males show the effects of aging to a greater extent than do females. After correction for the effects of aging, the adjusted values of stature were regressed on age to estimate secular trend of stature. For males, there is a general increase of stature with time, excepting those born around 1878, while females generally show random variation with time. Both male and female adjusted stature decrease sharply around 1878, for which alternative historical explanations are proposed, relating to differential migration and survival.     

Age-specific variation in the secular trend for stature: A comparison of samples from industrialized and nonindustrialized regions

Age-specific secular trend patterns for children in industrialized world regions have a regular pattern, beginning low at age 6 and increasing to a maximum at age 10 to 14, then declining. While magnitude differs, the patterns are ordinarily parallel, especially in the female samples. However, age-specific secular trend values for children from developing regions, or from areas of industrialized countries not benefitting substantially from development, are irregular in pattern and magnitude. Consequently, it is difficult to predict age at maximal secular change. We suggest that fluctuating environmental circumstances in these developing countries influence growth and, hence, the pattern of secular trend. As more stable environmental conditions relating to growth are present in the industrialized countries, this leads to more stable patterns of growth and age-specific patterns of secular change.     

Founder effect and prevalence of myotonic dystrophy in South Africans: molecular studies.

A high prevalence of myotonic dystrophy (DM) has been described in South African Caucasoid Afrikaans-speaking families in the northern Transvaal. Evidence is presented for a strong founder effect, with a single haplotype occurring on 68% of all Caucasoid DM chromosomes; among the Afrikaans speakers, the proportion was 83%. In addition to this major haplotype, five minor DM haplotypes in the Caucasoids and two minor haplotypes in DM individuals of mixed ancestry were found. All DM chromosomes, however, had a common haplotype core, namely, Alu (ins), HinfI-2 (intron 9), and TaqI-2 (D19S463). We have detected significant linkage disequilibrium between the DM mutation and particular alleles of the extragenic markers D19S112 and D19S207. Significant differences were found in allele and haplotype distributions in the Caucasoid DM and non-DM chromosomes and Negroid non-DM chromosomes. These findings together with the strong association of allele 3 at the D19S63 locus on 93% (14/15) of the South African DM chromosomes suggest that the majority of present-day DM mutations in South African Caucasoids may have originated from a common initial founder who introduced one of the European ancestral mutations.     

Quantifying the biophysical and socioeconomic drivers of changes in forest and agricultural land in South and Southeast Asia

South and Southeast Asia (SSEA) has been a hotspot for land use and land cover change (LULCC) in the past few decades. The identification and quantification of the drivers of LULCC are crucial for improving our understanding of LULCC trends. So far, the biophysical and socioeconomic drivers of forest change have not been quantified at the regional scale, particularly for SSEA. In this study, we quantify the biophysical and socioeconomic drivers of forest change on a country‐by‐country basis in SSEA using an integrated quantitative methodology, which systematically accounts for previously published driver information and regional datasets. We synthesize more than 200 publications to identify the drivers of the forest change at different spatial scales in SSEA. Subsequently, we collect spatially explicit proxy data to represent the identified drivers. We quantify the dynamics of forest and agricultural land from 1992 to 2015 using the Climate Change Initiative (CCI) land cover data developed by the European Space Agency (ESA). A geographically weighted regression method is employed to quantify the spatially heterogeneous drivers of forest change. Our results show that socioeconomic drivers are more important than biophysical drivers for the conversion of forest to agricultural land in South Asia and maritime Southeast Asia. In contrast, biophysical drivers are more important than socioeconomic drivers for the conversion of agricultural land to forest in maritime Southeast Asia and less important in South Asia. Both biophysical and socioeconomic drivers contribute approximately equally to both changes in the mainland Southeast Asia region. By quantifying the dynamics of forest and agricultural land and the spatially explicit drivers of their changes in SSEA, this study provides a solid foundation for LULCC modeling and projection.     

Opportunity for natural selection in a Basque population and its secular trend: evolutionary implications of epidemic mortality

Analysis of the interaction between mortality patterns and opportunity for natural selection could help to elucidate potential evolutionary implications of epidemic mortality. In this paper secular trends are studied in relation to Crow's index (It) and its components of mortality (Im) and fertility (If), using parish records for family reconstitution in a Basque population. A principal components analysis (91% of the variance accounted for) showed marked quantitative and qualitative variations of Im and If depending on the stage of demographic transition of the population analyzed: In pretransitional societies the opportunity for natural selection is determined mainly by differential prereproductive mortality, whereas in posttransitional societies selection resulting from differential fertility plays a key role. The highest values for the mortality component (range 0.81-1.26) and for the relative contribution of Im, to It (range 47.1-57.2%) were observed in periods with a high incidence of infectious diseases and when the most severe mortality crises were detected (1830-1859, 1860-1889, and 1890-1919). A differential incidence of epidemic mortality was also found at prereproductive ages (before 16 years) and at reproductive ages (16-45 years), which provides strong support for the idea of the long-term genetic consequences of mortality crises.     

Experience of violence and socioeconomic position in South Africa: a national study

Background

Violence is a leading cause of morbidity and mortality in South Africa and needs to be researched from a public health perspective. Typically in violence research, socioeconomic position is used in the analysis to control for confounding. Social epidemiology approaches this variable as a primary determinant of interest and is used in this research to better understand the aetiology of violence in South Africa. We hypothesised that measures of socioeconomic position (employment, education and household wealth) would be inversely related to violence at the individual and household levels.

Methodology/Principal Findings

Data came from the1998 South African Demographic and Health Survey (SADHS). Measures of socioeconomic position used were employment, education and household wealth. Eighty-eight people (0.2%) received treatment for a violent injury in the previous 30 days and 103 households (0.9%) experienced a violent death in the previous year. Risk factors for violence at the individual level included employment (41% of those who experienced violence were employed vs. 27% of those who did not, p = 0.02), and education (those who experienced violence had on average, one year more education than those who did not, p = 0.04). Belonging to a household in the wealthiest quintile was protective against violence (OR: 0.32; 95% CI: 0.12–0.89). In contrast, at the household level all three measures of socioeconomic position were protective against the experience of a violent death. The only association to persist in the multivariate analysis was that between the wealth of the household and violence at the individual level.

Conclusions/Significance

Our hypothesis was supported if household wealth was used as the measure of socioeconomic position at the individual level. While more research is needed to inform the conflicting results observed between the individual and household levels, this analysis has begun to identify the disparities across the socioeconomic structure with respect to violent outcomes.     

Correlation of trimethylamine oxide and habitat depth within and among species of teleost fish: an analysis of causation

Most shallow-water teleosts have moderate levels of trimethylamine N-oxide (TMAO; approximately 50 mmol/kg wet mass), a common osmolyte in many other marine animals. Recently, muscle TMAO contents were found to increase linearly with depth in six families. In one hypothesis, this may be an adaptation to counteract the deleterious effects of pressure on protein function, which TMAO does in vitro. In another hypothesis, TMAO may be accumulated as a by-product of acylglycerol (AG) production, increasing with depth because of elevated lipid metabolisms known to occur in some deep-sea animals. Here we analyze muscle TMAO contents and total body AG (mainly triacyglycerol [TAG]) levels in 15 species of teleosts from a greater variety of depths than sampled previously, including eight individual species caught at two or more depths. Including data of previous studies (total of 17 species, nine families), there is an apparent sigmoidal increase in TMAO contents between 0- and 1.4-km depths, from about 40 to 150 mmol/kg. From 1.4 to 4.8 km, the increase appears to be linear (r2=0.91), rising to 261 mmol/kg at 4.8 km. The trend also occurred within species: in most cases in which a species was caught at two or more depths, TMAO was higher in the deeper-caught specimens (e.g., for Coryphaenoides armatus, TMAO was 173, 229, and 261 mmol/kg at 1.8, 4.1, and 4.8 km, respectively). TMAO contents not only were consistent within species at a given depth but also did not vary with season or over a wide range of body masses or TAG contents. Thus, no clear link between TMAO and lipid was found. However, TMAO contents might correlate with the rate (rather than content) of TAG production, which could not be quantified. Overall, the data strongly support the hypothesis that TMAO is adaptively regulated with depth in deep-sea teleosts. Whether lipid metabolism is the source of that TMAO is a question that remains to be tested fully.     

Testing the quality of nonadult Bayesian dental age assessment methods to juvenile skeletal remains: the Lisbon collection children and secular trend effects

Age estimation of nonadult skeletons from archaeological or forensic contexts has relied heavily on modern schedules of dental formation developed on samples of children of affluent populations. Although genetic factors have been considered to have had the greatest influence on population differences in dental development, increased interest has been placed on the role of environmental influences, such as differences in socioeconomic status and secular trends. This study evaluates the quality (i.e., accuracy and reliability) of two Bayesian dental age estimation methods to a sample of identified child skeletons from the Lisbon collection (20th century Portugal). The two Bayesian methods are developed on a reference sample of modern children from France, Ivory Coast, Iran, and Morocco. The test sample from Lisbon, compared to the reference sample, is separated by over 50 years of secular trends and comprises a lower socioeconomic segment. The two Bayesian methods show that the Lisbon children are consistently 1-year behind in dental age compared to the modern children of the reference sample. Environmental factors largely explain the differences between dental and chronological age in historic samples of nonadults.     

Keloids in rural black South Africans. Part 3: a lipid model for the prevention and treatment of keloid formations

In the third part of this study a basic lipid model (regarding phospholipids, triglycerides, cholesterol esters and free fatty acids) for keloids (n=20), compared with normal skin of keloid prone and non-keloid prone patients (n=20 of each), was constructed according to standard methods, to serve as a sound foundation for essential fatty acid supplementation strategies in the prevention and treatment of keloid formations. Essential fatty acid deficiency (EFAD) of the omega-6 series (linoleic acid (LA), g-linolenic acid (GLA), and dihomo-g-linolenic acid (DGLA)) and the omega-3 series (a-linolenic acid (ALA) and eicosapentaenoic acid (EPA)), but enhanced arachidonic acid (AA) levels, were prevalent in keloid formations. Enhanced AA, but a deficiency of AA precursors (LA, GLA and DGLA) and inflammatory competitors (DGLA and EPA), are inevitably responsible for the overproduction of pro-inflammatory metabolites (prostaglandin E(2)(PGE(2))) participating in the pathogenesis of inflammation. Of particular interest was the extremely high free oleic acid (OA) levels present, apart from the high free AA levels, in the keloid formations. OA stimulates PKC activity which, in turn, activates PLA(2)activity for the release or further release of AA from membrane pools. Interactions between EFAs, eicosanoids, cytokines, growth factors and free radicals can modulate the immune response and the immune system in undoubtedly involved in keloid formation. The histopathology of keloids can be adequately explained by: persistence of inflammatory- and cytokine-mediated reactions in the keloid/dermal interface and peripheral areas, where fibroblast proliferation and continuous depletion of membrane linoleic acid occur; microvascular regeneration and circulation of sufficient EFAs in the interface and peripheral areas, where maintenance of metabolic active fibroblasts for collagen production occur; microvessel occlusion and hypoxia in the central areas, where deprivation of EFAs and oxygen with consequent fibroblast apoptosis occur, while excessive collagen remain. All these factors contribute to different fibroblast populations present in: the keloid / dermal interface and peripheral areas where increases in fibroblast proliferation and endogenous TGF-b occur, and these metabolic active fibroblast populations are responsible for enhanced collagen production: the central areas where fibroblast populations under hypoxic conditions occur, and these fibroblasts are responsible for excessive collagen production. It was concluded that: fibroblast membrane EFAD of AA precursors and inflammatory competitors, but prevailing enhanced AA levels, can contribute to a chain of reactions eventually responsible for keloid formations.     

Human variation and body mass index: a review of the universality of BMI cut-offs, gender and urban-rural differences, and secular changes

Use of BMI as a surrogate for body fat percentage is debatable and universal BMI cut-off points do not seem appropriate; lower cut-off points than currently recommended by WHO should be used in some populations, especially in Asia. The adult WHO BMI database indicates that, on average, women are more obese than men, while men are more likely to be pre-obese than women. Urban rates of overweight and obesity are generally higher than rural rates in both sexes. The trend in pre-obesity and obesity over time is generally upward, with very marked increases in the USA and UK in both sexes over the last 10 years.     

Giant pandas are losing their edge: Population trend and distribution dynamic drivers of the giant panda

Comprehending the population trend and understanding the distribution range dynamics of species are necessary for global species protection. Recognizing what causes dynamic distribution change is crucial for identifying species' environmental preferences and formulating protection policies. Here, we studied the rear-edge population of the flagship species, giant pandas (Ailuropoda melanoleuca), to (1) assess their population trend using their distribution patterns, (2) evaluate their distribution dynamics change from the second (1988) to the third (2001) survey (2–3 Interval) and third to the fourth (2013) survey (3–4 Interval) using a machine learning algorithm (eXtremely Gradient Boosting), and (3) decode model results to identify driver factors in the first known use of SHapley Additive exPlanations. Our results showed that the population trends in Liangshan Mountains were worst in the second survey (k = 1.050), improved by the third survey (k = 0.97), but deteriorated by the fourth survey (k = 0.996), which indicates a worrying population future. We found that precipitation had the most significant influence on distribution dynamics among several potential environmental factors, showing a negative correlation between precipitation and giant panda expansion. We recommend that further research is needed to understand the microenvironment and animal distribution dynamics. We provide a fresh perspective on the dynamics of giant panda distribution, highlighting novel focal points for ecological research on this species. Our study offers theoretical underpinnings that could inform the formulation of more effective conservation policies. Also, we emphasize the uniqueness and importance of the Liangshan Mountains giant pandas as the rear-edge population, which is at a high risk of population extinction.     

Four Models of HIV Counseling and Testing: Utilization and Test Results in South Africa

Background

HIV Counseling and Testing (HCT) is the point-of-entry for pathways of HIV care and prevention. However, HCT is not reaching many who are HIV infected and this may be related to the HCT provision model. We describe HCT utilization and HIV diagnosis using four models of HCT delivery: clinic-based, urban mobile, rural mobile, and stand-alone.

Methods

Using cross-sectional data from routine HCT provided in South Africa, we described client characteristics and HIV test results from information collected during service delivery between January 2009 and June 2012.

Results

118,358 clients received services at clinic-based units, 18,597; stand-alone, 28,937; urban mobile, 38,840; and rural mobile, 31,984. By unit, clients were similar in terms of median age (range 28–31), but differed in sex distribution, employment status, prior testing, and perceived HIV risk. Urban mobile units had the highest proportion of male clients (52%). Rural mobile units reached the highest proportion of clients with no prior HCT (61%) and reporting no perceived HIV risk (64%). Overall, 10,862 clients (9.3%) tested HIV-positive.

Conclusions

Client characteristics varied by HCT model. Importantly, rural and urban mobile units reached more men, first-time testers, and clients who considered themselves to be at low risk for HIV.     

Detection of trend and seasonal changes in non-stationary remote sensing data: Case study of Tunisia vegetation dynamics

The availability of long-term time series (TS) derived from remote sensing (RS) images is favorable for the analysis of vegetation variation and dynamics. However, the choice of appropriate methods is a challenging task. This article presented an experimental comparison of four methods widely used for the detection of long-term trend and seasonal changes of TS, with a case study in north-western Tunisia. The four methods are the Ensemble Empirical Mode Decomposition (EEMD), Multi-Resolution Analysis-Wavelet transform (MRA-WT), Breaks for Additive Season and Trend (BFAST), and Detecting Breakpoints and Estimating Segments in Trend (DBEST). Their efficiencies were compared by analysing Normalized Difference Vegetation Index (NDVI) TS from 2001 to 2017 in the study area, obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) observations. The variations of long-term NDVI trends were analysed using non-parametric statistical tests. Results indicated that MRA-WT gave efficient results for both trend and seasonal changes, especially in forest area. Moreover, it exhibited the fastest efficiency in terms of time of execution and thus recommended for detecting detailed features (such as forest fire detection). DBEST also showed a good performance for trend detection in forest area as MRA-WT, however, it was more constrained to a longer computational time of execution. BFAST and EEMD exhibited a better performance in bare soil and cropland areas, and the latter can be taken as an appropriate and fast alternative for a general long-term trend overview with long TS.     

Self-efficacy difference among patients with cancer with different socioeconomic status: Application of latent class analysis and standardization and decomposition analysis

IntroductionAlthough the relationship between partial socioeconomic status (SES) and self-efficacy has been studied in previous studies, few research have examined self-efficacy difference among patients with cancer with different SES.MethodsA cross-sectional survey involving 764 patients with cancer was completed. Latent class analysis (LCA) was applied to identify distinct groups of patients with cancer using four SES indicators (education, income, employment status and health insurance status). Standardization and decomposition analysis (SDA) was then used to examine differences in patients’ self-efficacy among SES groups and the components of the differences attributed to confounding factors, such as gender, age, anxiety, depression and social support.ResultsParticipants were classified into four distinctive SES groups via using LCA method, and the observed self-efficacy level significantly varied by SES groups; as theorized, higher self-efficacy was associated with higher SES. The self-efficacy differences by SES groups were decomposed into “real” group differences and factor component effects that are attributed to group differences in confounding factor compositions.ConclusionSelf-efficacy significantly varies by SES. Social support significantly confounded the observed differences in self-efficacy between different SES groups among Chinese patients with cancer.     

Callaloo Nation: Metaphors of Race and Religious Identities among South Asians in Trinidad

Callaloo Nation: Metaphors of Race and Religious Identities among South Asians in Trinidad . Aisha Khan. Durham, NC: Duke University Press, 2004. 264 pp.