Variability in energy expenditure is much greater in males than females

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Variation in human water turnover associated with environmental and lifestyle factors

Water is essential for survival, but one in three individuals worldwide (2.2 billion people) lacks access to safe drinking water. Water intake requirements largely reflect water turnover (WT), the water used by the body each day. We investigated the determinants of human WT in 5604 people from the ages of 8 days to 96 years from 23 countries using isotope-tracking (2H) methods. Age, body size, and composition were significantly associated with WT, as were physical activity, athletic status, pregnancy, socioeconomic status, and environmental characteristics (latitude, altitude, air temperature, and humidity). People who lived in countries with a low human development index (HDI) had higher WT than people in high-HDI countries. On the basis of this extensive dataset, we provide equations to predict human WT in relation to anthropometric, economic, and environmental factors.acceptedVersio

Greater male variability in daily energy expenditure develops through puberty

There is considerably greater variation in metabolic rates between men than between women, in terms of basal, activity and total (daily) energy expenditure (EE). One possible explanation is that EE is associated with male sexual characteristics (which are known to vary more than other traits) such as musculature and athletic capacity. Such traits might be predicted to be most prominent during periods of adolescence and young adulthood, when sexual behaviour develops and peaks. We tested this hypothesis on a large dataset by comparing the amount of male variation and female variation in total EE, activity EE and basal EE, at different life stages, along with several morphological traits: height, fat free mass and fat mass. Total EE, and to some degree also activity EE, exhibit considerable greater male variation (GMV) in young adults, and then a decrease in the degree of GMV in progressively older individuals. Arguably, basal EE, and also morphometrics, do not exhibit this pattern. These findings suggest that single male sexual characteristics may not exhibit peak GMV in young adulthood, however total and perhaps also activity EE, associated with many morphological and physiological traits combined, do exhibit GMV most prominently during the reproductive life stages

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Greater male variability in daily energy expenditure develops through puberty

There is considerably greater variation in metabolic rates between men than between women, in terms of basal, activity and total (daily) energy expenditure (EE). One possible explanation is that EE is associated with male sexual characteristics (which are known to vary more than other traits) such as musculature and athletic capacity. Such traits might be predicted to be most prominent during periods of adolescence and young adulthood, when sexual behaviour develops and peaks. We tested this hypothesis on a large dataset by comparing the amount of male variation and female variation in total EE, activity EE and basal EE, at different life stages, along with several morphological traits: height, fat free mass and fat mass. Total EE, and to some degree also activity EE, exhibit considerable greater male variation (GMV) in young adults, and then a decrease in the degree of GMV in progressively older individuals. Arguably, basal EE, and also morphometrics, do not exhibit this pattern. These findings suggest that single male sexual characteristics may not exhibit peak GMV in young adulthood, however total and perhaps also activity EE, associated with many morphological and physiological traits combined, do exhibit GMV most prominently during the reproductive life stages

Factors influencing contraceptive use or non-use among Aboriginal and Torres Strait Islander people: a systematic review and narrative synthesis

Background: The Australian population has an unmet need for contraception. However, evidence suggests contraceptive patterns of Aboriginal and Torres Strait Islander populations are unique. To tailor contraceptive services and meet the contraceptive needs of Aboriginal and Torres Strait Islander people, it is important to understand the contributing factors to contraceptive use and non-use. Methods: This study aimed to systematically review and narratively synthesise the evidence exploring the factors influencing contraceptive use among Aboriginal and Torres Strait Islander people. A systematic literature search was initially run in September 2016 and was updated again in April and August of 2018. A qualitative narrative synthesis was conducted from 2018 to 2019. Factors influencing contraceptive use or non-use were explored using a Social Ecological Model. Results: The review identified 17 studies meeting the inclusion criteria published between 1972 and 2018. Most of the included studies were qualitative (n = 11), with the remaining studies being mixed methods (n = 3) or quantitative (n = 3). The majority focused on either a localised geographic area or specific Aboriginal or Torres Strait Islander community (n = 11). One study specifically focused on factors influencing contraceptive use, albeit among postpartum women. The remaining studies discussed factors influencing contraceptive use within the context of risky behaviour, sexual transmitted infections, or contraceptive practices more generally. Factors unique to individual communities included community attitudes (e.g. importance of not being too young to have a baby), specific cultural norms (e.g. subincising the penis as part of transition to manhood), and access to culturally appropriate health services. Other factors, including contraceptive characteristics (e.g. discomfort of condoms) and reproductive coercion (e.g. partner wants a baby), were similar to those found in the broader population of Australia and internationally. Most studies were lacking in quality, warranting more methodologically sound studies in the future to further assess the factors contributing to contraceptive use or non-use among Aboriginal and Torres Strait Islander people. Conclusions: Identifying community specific facilitators, as well as understanding the more broadly applicable factors contributing to contraceptive use or non-use, is essential if wanting to offer appropriate contraceptive services within an Aboriginal or Torres Strait Islander community

Stages of condom use in a high HIV-risk sample

The goals were to (1) clarify high risk individuals into one of five stages of readiness for consistent condom use based on the Transtheoretical Model of behavior change (e.g., Prochaska, Norcross and DiClemente, 1994); (2) investigate whether frequency of condom use was different for vaginal vs. anal sex, and for steady vs. other partners; and (3) explore whether condom use was related to several demographic variables. Street interviews were conducted in six major geographic areas across the United States on a diverse sample of 345 individuals engaging in high HIV-risk behaviors. Percentages of individuals found in each of five stages of condom use were: 36% Precontemplators, 15% Contemplators, 7% in Preparation, 7% in Action, and 35% in Maintenance. Individuals used condoms more with other, casual partners than with a steady partner, and slightly more when engaging in anal sex rather than vaginal sex. Condoms were also used more by: men, Caucasians, non-heterosexuals, and those who were not in a steady relationship than by others not in these categories. Still, the majority of high-risk individuals were not using condoms and were not prepared to start. This presents an urgent need for effective interventions to encourage condom use