Changes in Weight,Waist Circumference and Compensatory Responses with Different Doses of Exercise among Sedentary,Overweight Postmenopausal Women

Background

It has been suggested that exercise training results in compensatory mechanisms that attenuate weight loss. However, this has only been examined with large doses of exercise. The goal of this analysis was to examine actual weight loss compared to predicted weight loss (compensation) across different doses of exercise in a controlled trial of sedentary, overweight or obese postmenopausal women (n = 411).

Methodology/Principal Findings

Participants were randomized to a non-exercise control (n = 94) or 1 of 3 exercise groups; exercise energy expenditure of 4 (n = 139), 8 (n = 85), or 12 (n = 93) kcal/kg/week (KKW). Training intensity was set at the heart rate associated with 50% of each woman''s peak VO₂ and the intervention period was 6 months. All exercise was supervised. The main outcomes were actual weight loss, predicted weight loss (exercise energy expenditure/ 7700 kcal per kg), compensation (actual minus predicted weight loss) and waist circumference. The study sample had a mean (SD) age 57.2 (6.3) years, BMI of 31.7 (3.8) kg/m², and was 63.5% Caucasian. The adherence to the intervention was >99% in all exercise groups. The mean (95% CI) weight loss in the 4, 8 and 12 KKW groups was −1.4 (−2.0, −0.8), −2.1 (−2.9, −1.4) and −1.5 (−2.2, −0.8) kg, respectively. In the 4 and 8 KKW groups the actual weight loss closely matched the predicted weight loss of −1.0 and −2.0 kg, respectively, resulting in no significant compensation. In the 12 KKW group the actual weight loss was less than the predicted weight loss (−2.7 kg) resulting in 1.2 (0.5, 1.9) kg of compensation (P<0.05 compared to 4 and 8 KKW groups). All exercise groups had a significant reduction in waist circumference which was independent of changes in weight.

Conclusion

In this study of previously sedentary, overweight or obese, postmenopausal women we observed no difference in the actual and predicted weight loss with 4 and 8 KKW of exercise (72 and 136 minutes respectively), while the 12 KKW (194 minutes) produced only about half of the predicted weight loss. However, all exercise groups had a significant reduction in waist circumference which was independent of changes in weight.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT 00011193","term_id":"NCT00011193"}}NCT 00011193     

Social transmission of fear in rats: the role of 22-kHz ultrasonic distress vocalization

Background

Social alarm calls alert animals to potential danger and thereby promote group survival. Adult laboratory rats in distress emit 22-kHz ultrasonic vocalization (USV) calls, but the question of whether these USV calls directly elicit defensive behavior in conspecifics is unresolved.

Methodology/Principal Findings

The present study investigated, in pair-housed male rats, whether and how the conditioned fear-induced 22-kHz USVs emitted by the ‘sender’ animal affect the behavior of its partner, the ‘receiver’ animal, when both are placed together in a novel chamber. The sender rats’ conditioned fear responses evoked significant freezing (an overt evidence of fear) in receiver rats that had previously experienced an aversive event but not in naïve receiver rats. Permanent lesions and reversible inactivations of the medial geniculate nucleus (MGN) of the thalamus effectively blocked the receivers’ freeezing response to the senders'' conditioned fear responses, and this occurred in absence of lesions/inactivations impeding the receiver animals'' ability to freeze and emit 22-kHz USVs to the aversive event per se.

Conclusions/Significance

These results—that prior experience of fear and intact auditory system are required for receiver rats to respond to their conspecifics'' conditioned fear responses—indicate that the 22-kHz USV is the main factor for social transmission of fear and that learning plays a crucial role in the development of social signaling of danger by USVs.     

Who's the Boss? How Communicative Competence Is Defined in a Multilingual Preschool Classroom

This article investigates how classroom communicative competence was defined in a multilingual preschool classroom. Sociolinguistic analysis of a conflict event, and the larger classroom context, reveals the norms and values that influenced the behaviors of an English-speaking teacher, bilingual teaching assistant, and two Chinese-speaking preschoolers. The article identifies problems that teachers face when they attempt to value the children's home languages at the same time that they socialize them into U.S. English-speaking classrooms.     

The “Buruli Score”: Development of a Multivariable Prediction Model for Diagnosis of Mycobacterium ulcerans Infection in Individuals with Ulcerative Skin Lesions,Akonolinga, Cameroon

Background

Access to laboratory diagnosis can be a challenge for individuals suspected of Buruli Ulcer (BU). Our objective was to develop a clinical score to assist clinicians working in resource-limited settings for BU diagnosis.

Methododology/Principal Findings

Between 2011 and 2013, individuals presenting at Akonolinga District Hospital, Cameroon, were enrolled consecutively. Clinical data were collected prospectively. Based on a latent class model using laboratory test results (ZN, PCR, culture), patients were categorized into high, or low BU likelihood. Variables associated with a high BU likelihood in a multivariate logistic model were included in the Buruli score. Score cut-offs were chosen based on calculated predictive values. Of 325 patients with an ulcerative lesion, 51 (15.7%) had a high BU likelihood. The variables identified for the Buruli score were: characteristic smell (+3 points), yellow color (+2), female gender (+2), undermining (+1), green color (+1), lesion hyposensitivity (+1), pain at rest (-1), size >5cm (-1), locoregional adenopathy (-2), age above 20 up to 40 years (-3), or above 40 (-5). This score had AUC of 0.86 (95%CI 0.82–0.89), indicating good discrimination between infected and non-infected individuals. The cut-off to reasonably exclude BU was set at scores <0 (NPV 96.5%; 95%CI 93.0–98.6). The treatment threshold was set at a cut-off ≥4 (PPV 69.0%; 95%CI 49.2–84.7). Patients with intermediate BU probability needed to be tested by PCR.

Conclusions/Significance

We developed a decisional algorithm based on a clinical score assessing BU probability. The Buruli score still requires further validation before it can be recommended for wide use.     

Vanadium ion stimulation of chloride secretion by rabbit colonic epithelium

Ionized forms of vanadium are known to exert diverse biological activities. Of particular interest in the inhibitory action of the vanadium ion on (Na+ + K+)-ATPase. This report describes another action of the vanadium ion on the rabbit colonic epithelium. Micromolar quantities of vanadate, applied to the serosal side of the isolated rabbit colonic epithelium, result in a stimulation of electrogenic chloride secretion by this epithelium. Sodium transport is unaffected by the vanadium ion in the concentrations used in this study. It is proposed that the vanadyl ion activates adenylate cyclase and thereby initiates subsequent secretory events.