YAP insertion signature in South Asia

A total of 2169 samples from 21 tribal populations from different regions of India were scanned for the Y-chromosome Alu polymorphism. This study reports, for the first time, high frequencies (8-65%) of Y Alu polymorphic (YAP) insertion in northeast Indian tribes. All seven Jarawa samples from the Andaman and Nicobar islands had the YAP insertion, in conformity with an earlier study of Andaman Islanders. One isolated case with haplotype E* was found in Dungri Bhill, a western Indian population, while YAP insertion in northeast India and Andaman tribes was found in association with haplotype D* (M168, M174). YAP insertion frequencies reported in the mainland Indian populations are negligible, according to previous studies. Genetic drift may be the causative factor for the variable frequency of the YAP insertion in the mainland populations, while the founder effect may have resulted in the highest incidence of haplotype D among the Andaman Islanders. The results of YAP insertion and the evidence of previous mtDNA studies indicate an early out of Africa migration to the Andaman and Nicobar Islands. The findings of YAP insertion in northeast Indian tribes are very significant for understanding the evolutionary history of the region.     

Urinary metal concentrations among mothers and children in a Mexico City birth cohort study

Personal care product use is a potential source of metals exposure among children, but studies have been limited. We measured urinary concentrations of 10 metals (aluminum, arsenic [As], barium [Ba], cadmium, cobalt [Co], lead [Pb], manganese [Mn], molybdenum [Mo], nickel, and zinc [Zn]) in third trimester pregnant women (n?=?212) and their children at 8–14 years of age (n?=?250). Demographic factors (child sex, age, socioeconomic status, and maternal education), body mass index (BMI) z-score, and child personal care product use in the 24?h prior to urine collection were examined as predictors of urinary metal concentrations. Metals were detected in 80–100% of urine samples, with significant differences in maternal versus childhood levels. However, metal concentrations were not strongly correlated within or between time points. In linear regression models including all demographic characteristics, BMI z-score, and specific gravity, age was associated with higher Co (6% [95% CI: 2, 10]), while BMI z-score was associated with lower Mo (-6% [95% CI: -11, -1). In addition, significantly higher metal concentrations were observed among users of colored cosmetics (Mo: 42% [95% CI: 1, 99]), deodorant (Ba: 28% [3, 58]), hair spray/hair gel (Mn: 22% [3, 45]), and other toiletries (As: 50% [9, 108]), as well as with an increasing number of personal care products used (As: 7% [3, 11]) after adjustment for child sex, age, total number of products used, and specific gravity. However, significantly lower metal concentrations were noted for users of hair cream (As and Zn: -20% [-36, -2] and -21% [-35, -2], respectively), shampoo (Pb: -40% [-62, -7]), and other hair products (Pb: -44% [-65, -9]). We found that personal care product use may be a predictor of exposure to multiple metals among children. Further research is recommended to inform product-specific exposure source identification and related child health risk assessment efforts.     

Alternative evaluation metrics for risk adjustment methods

Risk adjustment is instituted to counter risk selection by accurately equating payments with expected expenditures. Traditional risk‐adjustment methods are designed to estimate accurate payments at the group level. However, this generates residual risks at the individual level, especially for high‐expenditure individuals, thereby inducing health plans to avoid those with high residual risks. To identify an optimal risk‐adjustment method, we perform a comprehensive comparison of prediction accuracies at the group level, at the tail distributions, and at the individual level across 19 estimators: 9 parametric regression, 7 machine learning, and 3 distributional estimators. Using the 2013–2014 MarketScan database, we find that no one estimator performs best in all prediction accuracies. Generally, machine learning and distribution‐based estimators achieve higher group‐level prediction accuracy than parametric regression estimators. However, parametric regression estimators show higher tail distribution prediction accuracy and individual‐level prediction accuracy, especially at the tails of the distribution. This suggests that there is a trade‐off in selecting an appropriate risk‐adjustment method between estimating accurate payments at the group level and lower residual risks at the individual level. Our results indicate that an optimal method cannot be determined solely on the basis of statistical metrics but rather needs to account for simulating plans' risk selective behaviors.     

Survey of ticks of domestic dogs and cattle in three Caribbean islands

Ticks and the pathogens they transmit can cause high morbidity and mortality in domestic animals. As part of a larger study to determine the tick‐borne pathogens infesting domestic animals and wildlife, the aim of this study was to survey the tick species infesting the canine and cattle populations in Trinidad, Tobago and St. Lucia. A total of 1,990 ticks were collected off 179 dogs in Trinidad (n = 163) and Tobago (n = 16) between June 2016 and 2018. Ticks were also collected from cattle throughout Trinidad (n = 1,098), Tobago (n = 306) and St. Lucia (n = 176). Collected ticks were morphologically identified using standard taxonomic keys. Tick‐infested dogs were characterized as pets (n = 161) or hunting dogs (n = 18). Only two tick species, Rhipicephalus sanguineus (1,926; 96.8%) and Amblyomma ovale (64; 3.2%), were found on the dogs. A total of 169 (94.4%) dogs and 10 (5.6%) dogs were infested with R. sanguineus and A. ovale, respectively. Three dogs (1.7%) were infested with both tick species. Hunting dogs or those closely associated with them were infested with A. ovale. Rhipicephalus sanguineus was widely distributed throughout both islands, whereas A. ovale was restricted to small foci in three rural settlements in both Trinidad (n = 2) and Tobago (n = 1). Rhipicephalus (Boophilus) microplus (n = 1,404) was the only tick species found in cattle from Trinidad (n = 62) and Tobago (n = 20), whilst R. B. microplus (n = 171) and Amblyomma variegatum (n = 5) were found infesting 14 and two heads of cattle, respectively, in St. Lucia. These preliminary findings will aid in determining whether there are links between ticks and tick‐borne pathogens associated with domestic, wildlife species and humans and give further insight into the potential movement of ticks and their pathogens between the human, animal and tropical forest interface.     

Relationship of muscle sympathetic nerve activity to insulin sensitivity

Purpose

An association between insulin resistance and activation of the sympathetic nervous system has been reported in previous studies. However, potential interactions between insulin sensitivity and sympathetic neural mechanisms in healthy people remain poorly understood. We conducted a study to determine the relationship between sympathetic activity and insulin resistance in young, healthy humans.

Methods

Thirty-seven healthy adults (18–35 years, BMI <28 kg m^?2) were studied. Resting muscle sympathetic nerve activity (MSNA) was measured with microneurography and insulin sensitivity of glucose and free fatty acid metabolism was measured during a hyperinsulinemic-euglycemic clamp with two levels of insulin.

Results

During lower doses of insulin, we found a small association between lower insulin sensitivity and higher MSNA (P < 0.05) but age was a cofactor in this relationship. Overall, we found no difference in insulin sensitivity between groups of low and high MSNA, but when women were analyzed separately, insulin sensitivity was lower in the high MSNA group compared with the low MSNA group of women.

Conclusions

These data suggest that MSNA and insulin sensitivity are only weakly associated with young healthy individuals and that age and sex may be important modifiers of this relationship.