Sticky central limit theorems on open books

Given a probability distribution on an open book (a metric space obtained by gluing a disjoint union of copies of a half-space along their boundary hyperplanes), we define a precise concept of when the Fr\'{e}chet mean (barycenter) is sticky. This nonclassical phenomenon is quantified by a law of large numbers (LLN) stating that the empirical mean eventually almost surely lies on the (codimension $1$ and hence measure $0$) spine that is the glued hyperplane, and a central limit theorem (CLT) stating that the limiting distribution is Gaussian and supported on the spine. We also state versions of the LLN and CLT for the cases where the mean is nonsticky (i.e., not lying on the spine) and partly sticky (i.e., is, on the spine but not sticky).Comment: Published in at http://dx.doi.org/10.1214/12-AAP899 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

Does habitat stability structure intraspecific genetic diversity? It’s complicated...

Regional phylogeographic studies have long been conducted in the southeastern United States for a variety of species. With some exceptions, many of these studies focus on single species or single clades of organisms, and those considering multiple species tend to focus on deep historical breaks causing differentiation. However, in many species more recent factors may be influencing genetic diversity. To understand the roles of historic and contemporary processes in structuring genetic diversity, we reanalyzed existing genetic data from Southeast of North America using approaches gleaned from phylogeographic and landscape genetic literature that were implemented across species including AMOVAs, PCoAs, Species Distribution Modelling, and tests of isolation by distance, environment, and habitat instability. Genetic variance was significantly partitioned by ecoregions, watersheds, and across phylogeographic breaks in the majority of species. Similarly, genetic variation was significantly associated with some combination of geographic or environmental distance or habitat instability in most species. Patterns of genetic variation were largely idiosyncratic across species. While habitat instability over time is significantly correlated with genetic diversity in some species, it appears generally less important than isolation by geographic or environmental distance. Our results suggest that many factors, both historical and contemporary, impact genetic diversity within a species, and more so, that these patterns aren’t always similar in closely related species. This supports the importance of species- specific factors and cautions against assumptions that closely related species will respond to historical and contemporary forces in similar ways

A collaborative network trial to evaluate the effectiveness of implementation strategies to maximize adoption of a school-based healthy lunchbox program: a study protocol

IntroductionAn important impediment to the large-scale adoption of evidence-based school nutrition interventions is the lack of evidence on effective strategies to implement them. This paper describes the protocol for a “Collaborative Network Trial” to support the simultaneous testing of different strategies undertaken by New South Wales Local Health Districts to facilitate the adoption of an effective school-based healthy lunchbox program (‘SWAP IT’). The primary objective of this study is to assess the effectiveness of different implementation strategies to increase school adoption of the SWAP across New South Wales Local Health Districts.MethodsWithin a Master Protocol framework, a collaborative network trial will be undertaken. Independent randomized controlled trials to test implementation strategies to increase school adoption of SWAP IT within primary schools in 10 different New South Wales Local Health Districts will occur. Schools will be randomly allocated to either the intervention or control condition. Schools allocated to the intervention group will receive a combination of implementation strategies. Across the 10 participating Local Health Districts, six broad strategies were developed and combinations of these strategies will be executed over a 6 month period. In six districts an active comparison group (containing one or more implementation strategies) was selected. The primary outcome of the trial will be adoption of SWAP IT, assessed via electronic registration records captured automatically following online school registration to the program. The primary outcome will be assessed using logistic regression analyses for each trial. Individual participant data component network meta-analysis, under a Bayesian framework, will be used to explore strategy-covariate interactions; to model additive main effects (separate effects for each component of an implementation strategy); two way interactions (synergistic/antagonistic effects of components), and full interactions.DiscussionThe study will provide rigorous evidence of the effects of a variety of implementation strategies, employed in different contexts, on the adoption of a school-based healthy lunchbox program at scale. Importantly, it will also provide evidence as to whether health service-centered, collaborative research models can rapidly generate new knowledge and yield health service improvements.Clinical trial registrationThis trial is registered prospectively with the Australian New Zealand Clinical Trials Registry (ACTRN12623000558628)

Categorization Reduces the Effect of Context On Hedonic Preference

When moderately hedonically positive test stimuli are presented following better-liked context stimuli, preferences between the test stimuli are reduced. This reduction in preference, hedonic condensation, occurs in settings that also produce negative hedonic contrast-the phenomenon in which moderately hedonically positive test stimuli seem less positive when they follow better-liked context stimuli. Subjects who were instructed that the context and test stimuli were from different categories exhibited less hedonic condensation. Those categories have smaller hedonic ranges than does the full stimulus set. The increase in preference magnitude with reduction in size of the hedonic range is predicted by Parducci\u27s (1995) range-frequency model

The support keeps me strong : Social support among South Africans ageing with HIV

Early in the HIV epidemic, living with HIV and ageing were mutually exclusive in African countries. Increased accessibility of antiretroviral therapies has changed this. Much is known of the experience of older South Africans as caregivers in the HIV epidemic, but less of the social support experience of those ageing with HIV. This chapter presents data from interviews conducted with 15 South Africans ageing with HIV in inner-city Johannesburg. Initial reports of ageing with HIV among populations of men who have sex with men in high-income countries found shrinking social networks, lack of support, and poor mental health, from the combined impacts of homophobia, ageism, and HIV-related stigma. In contrast, our participants reported amplified support, particularly from adult children. Women were additionally supported by siblings and men by spouses. Participants reported some emotional support, but financial and instrumental support were more common. At the same time, participants (particularly women) noted that their own caregiving roles did not diminish. Social networks of older people with HIV are diverse, and in the African setting, they cannot be assumed to be the same as in high-income countries. Consideration of such difference must be factored into support provision for this population

Poor sleep quality and sleep apnea are associated with higher resting energy expenditure in obese individuals with short sleep duration

A number of epidemiologic studies have reported an association between habitual short duration of sleep and obesity or diabetes. Either an inverse or U-shaped relationship between sleep duration and weight occurred, depending on the study. It is unclear whether chronic sleep deprivation and impaired sleep quality have a causal relationship with obesity, or whether they represent coincidental secular trends. The effect of chronic sleep deprivation on resting energy expenditure (REE) is not well characterized. It has been suggested that sleep deprivation through activation of the stress system and the sympathetic nervous system could lead to increased energy expenditure. The aim of this randomized, prospective, long-term, intervention trial was to investigate the relationship between sleep, REE, and stress hormones in a population of obese adult men and premenopausal women. The study was conducted at a tertiary, referral research clinical center. The presence and severity of sleep apnea, as well as sleep duration and quality, were determined in 126 obese individuals with the following characteristics: either sex: 30 males and 96 females; age: 40.5 ± 6.9 years; body mass index: 38.6 ± 6.5 kg/m2; sleep duration, 360 ± 50 min/night; and sleep efficiency, 79.5% ± 7.5%. The primary study outcome measures included (1) REE and respiratory quotient (RQ) assessed by indirect calorimetry, (2) sleep duration and sleep efficiency assessed by actigraphy, (3) daytime sleepiness assessed by the Epworth Sleepiness Scale questionnaire, (4) sleep quality estimated by questionnaires, and (5) sleep apnea evaluated by respiratory disturbance index (RDI). Levels of plasma adrenocorticotropic hormone (ACTH), serum cortisol, 24-hour urinary free cortisol (UFC), and 24-hour catecholamines were also measured. Resting energy expenditure was adjusted for fat mass, age, and sex. Respiratory disturbance index was directly correlated with adjusted REE (r = 0.307, P = 0.003) and RQ (r = 0.377, P = 0.001). There was an inverse correlation between sleep efficiency and RQ (r = −0.200, P = 0.033). Several sex differences were noted. The relationship between RDI and REE was stronger in men than in women (P = 0.035). Among women, there was a positive correlation between serum cortisol and the adjusted REE (r = 0.407, P = 0.001), and the Epworth sleepiness score tended to be inversely correlated with adjusted REE (r = −0.190, P = 0.086). Respiratory quotient was positively related to RDI in women (P < 0.004), whereas subjective sleep time was related to RQ in men (P < 0.008). Three parameters (RDI, serum cortisol, and urinary norepinephrine) were positively related to REE in a linear regression model (P < 0.05), whereas only serum cortisol was also directly correlated with adjusted REE (P < 0.007). These data suggest that poor sleep quality is associated with increased REE. The higher RQ in patients with sleep apnea indicates a shift from fat toward carbohydrate oxidation and activation of the stress system

Poor Sleep Quality and Sleep Apnea Are Associated with Higher Resting Energy Expenditure in Obese Individuals with Short Sleep Duration

Context: Epidemiological studies reported an inverse or U-shaped relationship between sleep duration and weight. The relationship between sleep and resting energy expenditure (REE) has not been well characterized. Objective: The aim of the study was to determine the relationship between sleep, REE, and stress hormones. Design and Setting: We conducted a cross-sectional evaluation of a prospective cohort study at a tertiary referral research clinical center. Subjects: Subjects included 126 obese individuals (30 males, 96 females; age, 40.5 +/- 6.9 yr; body mass index, 38.6 +/- 6.5 kg/m(2); sleep duration, 360 +/- 50 min/night; and sleep efficiency, 79.5 +/- 7.5%). Main Outcome Measure(s): REE and respiratory quotient (RQ) were assessed by indirect calorimetry. Sleep duration and sleep efficiency were assessed by actigraphy. Sleep quality was estimated by questionnaires, and sleep apnea was evaluated by respiratory disturbance index (RDI). Morning plasma ACTH, serum cortisol, and 24-h urinary free cortisol and catecholamines were also measured. Results: RDI was positively correlated with REE adjusted by fat-free mass (r = 0.307; P = 0.003) and RQ (r = 0.377; P < 0.001). Sleep efficiency was inversely correlated with RQ (r = -0.200; P = 0.033). The relationship of RDI score and REE was stronger in men than women (P = 0.03). In women, serum cortisol was positively correlated (r = 0.407; P < 0.001), and Epworth sleepiness score tended to be inversely (r = -0.190; P = 0.086) correlated with adjusted REE. The RQ was positively related to RDI in women, whereas subjective sleep time was related to RQ in men. In a multiple regression model, RDI, serum cortisol, and urinary norepinephrine were directly related to REE, whereas serum cortisol also directly related to adjusted REE. Conclusion: Poor sleep quality was associated with increased REE, a higher RQ indicating a shift from fat toward carbohydrate oxidation, and activation of the stress system. (J Clin Endocrinol Metab 97: 2881-2889, 2012

Balkanatolia: The insular mammalian biogeographic province that partly paved the way to the Grande Coupure

International audienceThe Grande Coupure corresponds to a major episode of faunal turnover in western Europe around the Eocene-Oligocene boundary that is generally attributed to the influx of multiple clades of Asian mammals. However, Asian mammal clades begin to appear in the fossil record of southeastern Europe during the middle Eocene, 5–10 million years prior to the Grande Coupure. How and when these Asian mammal clades colonized southeastern Europe remains poorly understood, partly because the fossil record of mammals from nearby Anatolia is characterized by marked endemism and very limited exchanges with Asia during most of the Eocene. We resolve this apparent paradox by reviewing the age of existing paleontological sites from the Balkans to the Caucasus and documenting the oldest Asian perissodactyls found so far in central Anatolia, which date to the lower or middle Priabonian, 37.8 to 35 million years ago, on the basis of geochronological, magnetostratigraphic and biostratigraphic data. We show that the Eocene distribution of mammals across Eurasia supports a previously unrecognized biogeographic province, designated here as Balkanatolia, spanning the eastern and central segment of the Neotethyan margin. Isolated from mainland Eurasia during the early and middle Eocene, Balkanatolia formed a low-topography archipelago where endemic and anachronistic mammals thrived. We show that the Eocene fossil record supports Balkanatolia having been colonized by Asian ungulates and rodents by the late Bartonian (mammalian Paleogene biohorizon MP16), following the establishment of a continuous terrestrial dispersal corridor across the central segment of the Neotethyan margin. This colonization event was facilitated by a drop in global eustatic sea level and a tectonically-driven sea retreat in eastern Anatolia and the Lesser Caucasus during the late middle Eocene. These paleogeographic changes instigated the demise of Balkanatolia as a distinct biogeographic province and paved the way for the dispersal of Asian endemic clades before and during the Grande Coupure in western Europe

Obstructive Sleep Apnea Is a Predictor of Abnormal Glucose Metabolism in Chronically Sleep Deprived Obese Adults

CONTEXT: Sleep abnormalities, including obstructive sleep apnea (OSA), have been associated with insulin resistance. OBJECTIVE: To determine the relationship between sleep, including OSA, and glucose parameters in a prospectively assembled cohort of chronically sleep-deprived obese subjects. DESIGN: Cross-sectional evaluation of a prospective cohort study. SETTING: Tertiary Referral Research Clinical Center. MAIN OUTCOME MEASURES: Sleep duration and quality assessed by actigraphy, sleep diaries and questionnaires, OSA determined by a portable device; glucose metabolism assessed by oral glucose tolerance test (oGTT), and HbA1c concentrations in 96 obese individuals reporting sleeping less than 6.5 h on a regular basis. RESULTS: Sixty % of subjects had an abnormal respiratory disturbance index (RDI≥5) and 44% of these subjects had abnormal oGTT results. Severity of OSA as assessed by RDI score was associated with fasting glucose (R = 0.325, p = 0.001) and fasting insulin levels (ρ = 0.217, p = 0.033). Subjects with moderate to severe OSA (RDI>15) had higher glucose concentrations at 120 min than those without OSA (RDI<5) (p = 0.017). Subjects with OSA also had significantly higher concentrations of plasma ACTH (p = 0.009). Several pro-inflammatory cytokines were higher in subjects with OSA (p<0.050). CRP levels were elevated in this sample, suggesting increased cardiovascular risk. CONCLUSIONS: OSA is associated with impaired glucose metabolism in obese, sleep deprived individuals. Since sleep apnea is common and frequently undiagnosed, health care providers should be aware of its occurrence and associated risks