Free-ranging eastern chipmunks (Tamias striatus) infected with bot fly (Cuterebra emasculator) larvae have higher resting but lower maximum metabolism

Given the ubiquity and evolutionary importance of parasites, their effect on the energy budget of mammals remains surprisingly unclear. The eastern chipmunk (Tamias striatus (L., 1758)) is a burrowing rodent that is commonly infected by cuterebrid bot fly (Cuterebra emasculator Fitch, 1856) larvae. We measured resting metabolic rate (RMR) and cold-induced [Vo.sub.2]-max (under heliox atmosphere) in 20 free-ranging individuals, of which 4 individuals were infected by one or two larva. We found that RMR was significantly higher in chipmunks infected by bot fly larvae (mean [+ or -] SE = 0.88 [+ or -] 0.05 W) than in uninfected individuals (0.74 [+ or -] 0.02 W). In contrast, V[O.sub.2]-max was significantly lower in chipmunks infected by bot fly larvae (4.96 [+ or -] 0.70 W) than in uninfected individuals (6.37 [+ or -] 0.16 W). Consequently, the aerobic scope (ratio of [Vo.sub.2]-max to RMR) was negatively correlated with the number of bot fly larvae (infected individuals = 5.74 [+ or -] 1.03 W; noninfected individuals = 8.67 [+ or -] 0.26 W). Finally, after accounting for the effects of body mass and bot fly parasitism on RMR and [Vo.sub.2]-max, there was no correlation between the two variables among individuals within our population. In addition to providing the first estimate of [Vo.sub.2]-max in T. striatus, these results offer additional evidence that bot fly parasitism has significant impacts on the metabolic ecology of this host species.

Blind extraction using fractional lower-order statistics

In traditional method to blindly extract interesting source signals sequentially, the second-order or higher-order statistics of signals are often utilized. However, for impulsive sources, both of the second-order and higher-order statistics may degenerate. Therefore, it is necessary to exploit new method for the blind extraction of impulsive sources. Based on the best compression-reconstruction principle, a novel model is proposed in this work, together with the corresponding algorithm. The proposed method can be used for blind extraction of sources which are distributed from alpha stable process. Simulations are given to illustrate availability and robustness of our algorithm.

Cycling time to failure is better maintained by cold than contrast or thermoneutral lower-body water immersion in normothermia

Purpose
To examine the effects of four commonly used recovery treatments applied between two bouts of intense endurance cycling on the performance of the second bout in normothermia (~21 °C).

Methods
Nine trained men completed two submaximal exhaustive cycling bouts (Ex1 and Ex2: 5 min at ~50 % V˙O2 peak, followed by 5 min at ~60 % V˙O2 peak and then ~80 % V˙O2 peak to failure) separated by 30 min of (a) cold water immersion at 15 °C (C15), (b) contrast water therapy alternating 2.5 min at 8 °C and 2.5 min at 40 °C (CT), (c) thermoneutral water immersion at 34 °C (T34) and (d) cycling at ~40 % V˙O2 peak (AR).

Results
Exercise performance, cardiovascular and metabolic responses during Ex1 were similar among all trials. However, time to failure (~80 % V˙O2 peak bout) during Ex2 was significantly (P < 0.05) longer in C15 (18.0 ± 1.6) than in CT (14.5 ± 1.5), T34 (12.4 ± 1.4) and AR (10.6 ± 1.0); and it was also longer (P < 0.05) in CT than AR. Core temperature and heart rate were significantly (P < 0.05) lower during the initial ~15 min of Ex2 during C15 compared with all other conditions but they reached similar levels at the end of Ex2.

Conclusions
A 30 min period of C15 was more beneficial in maintaining intense submaximal cycling performance than CT, T34 and AR; and CT was also more beneficial than T34 and AR. These effects were not mediated by the effect of water immersion per se, but by the continuous (C15) or intermittent (CT) temperature stimulus (cold) applied throughout the recovery.

Is lower income associated with an increased likelihood of qualification for treatment for osteoporosis in Canadian women?

The authors examined whether low income was associated with an increased likelihood of treatment qualification for osteoporotic fracture probability determined by Canada FRAX in women aged ≥50 years. A significant negative linear association was observed between income and treatment qualification when FRAX included bone mineral density (BMD), which may have implications for clinical practice.

Low health-related quality of life in school-aged children in Tonga, a lower-middle income country in the South Pacific

Background:
Ensuring a good life for all parts of the population, including children, is high on the public health agenda in most countries around the world. Information about children’s perception of their health-related quality of life (HRQoL) and its socio-demographic distribution is, however, limited and almost exclusively reliant on data from Western higher income countries.

Objectives:
To investigate HRQoL in schoolchildren in Tonga, a lower income South Pacific Island country, and to compare this to HRQoL of children in other countries, including Tongan children living in New Zealand, a high-income country in the same region.

Design:
A cross-sectional study from Tonga addressing all secondary schoolchildren (11–18 years old) on the outer island of Vava’u and in three districts of the main island of Tongatapu (2,164 participants). A comparison group drawn from the literature comprised children in 18 higher income and one lower income country (Fiji). A specific New Zealand comparison group involved all children of Tongan descendent at six South Auckland secondary schools (830 participants). HRQoL was assessed by the self-report Pediatric Quality of Life Inventory 4.0.

Results:
HRQoL in Tonga was overall similar in girls and boys, but somewhat lower in children below 15 years of age. The children in Tonga experienced lower HRQoL than the children in all of the 19 comparison countries, with a large difference between children in Tonga and the higher income countries (Cohen’s d 1.0) and a small difference between Tonga and the lower income country Fiji (Cohen’s d 0.3). The children in Tonga also experienced lower HRQoL than Tongan children living in New Zealand (Cohen’s d 0.6).

Conclusion:
The results reveal worrisome low HRQoL in children in Tonga and point towards a potential general pattern of low HRQoL in children living in lower income countries, or, alternatively, in the South Pacific Island countries.