Search for Daily Modulation of MeV Dark Matter Signals with DAMIC-M.

Dark matter (DM) particles with sufficiently large cross sections may scatter as they travel through Earth's bulk. The corresponding changes in the DM flux give rise to a characteristic daily modulation signal in detectors sensitive to DM-electron interactions. Here, we report results obtained from the first underground operation of the DAMIC-M prototype detector searching for such a signal from DM with MeV-scale mass. A model-independent analysis finds no modulation in the rate of 1 e^{-} events with sidereal period, where a DM signal would appear. We then use these data to place exclusion limits on DM in the mass range [0.53,2.7] MeV/c^{2} interacting with electrons via a dark photon mediator. Taking advantage of the time-dependent signal we improve by ∼2 orders of magnitude on our previous limit obtained from the total rate of 1 e^{-} events, using the same dataset. This daily modulation search represents the current strongest limit on DM-electron scattering via ultralight mediators for DM masses around 1 MeV/c^{2}.

First Constraints from DAMIC-M on Sub-GeV Dark-Matter Particles Interacting with Electrons.

We report constraints on sub-GeV dark matter particles interacting with electrons from the first underground operation of DAMIC-M detectors. The search is performed with an integrated exposure of 85.23 g days, and exploits the subelectron charge resolution and low level of dark current of DAMIC-M charge-coupled devices (CCDs). Dark-matter-induced ionization signals above the detector dark current are searched for in CCD pixels with charge up to 7e^{-}. With this dataset we place limits on dark matter particles of mass between 0.53 and 1000 MeV/c^{2}, excluding unexplored regions of parameter space in the mass ranges [1.6,1000] MeV/c^{2} and [1.5,15.1] MeV/c^{2} for ultralight and heavy mediator interactions, respectively.

Improved transition to adult care in youth with type 1 diabetes: a pragmatic clinical trial.

AIMS/HYPOTHESIS: Youth with type 1 diabetes are at high risk for loss to follow-up during the transition from paediatric to adult diabetes care. Our aim was to assess the effect of a communication technology enhanced transition coordinator intervention compared with usual care on clinic attendance among transitioning youth with type 1 diabetes. METHODS: In this open label, pragmatic clinical trial of youth with type 1 diabetes, aged 17-18 years, transitioning from paediatric to adult diabetes care, the intervention group received support from a transition coordinator who used communication technology and the control group received usual care. The primary outcome was the proportion of individuals that did not attend at least one routine clinic visit in adult diabetes care within 1 year after transfer. Secondary outcomes included diabetes-related clinical outcomes and quality of life measures. RESULTS: There were no baseline differences in age, sex, HbA1c and number of follow-up visits, emergency department visits and diabetic ketoacidosis admissions in the 1 year prior to transition between the usual care (n = 101) and intervention (n = 102) groups. In the year following transfer, 47.1% in the usual care group vs 11.9% in the intervention group did not attend any outpatient diabetes appointments (p < 0.01). There were no differences in glycaemic control or diabetic ketoacidosis post transfer. CONCLUSIONS/INTERPRETATION: Our intervention was successful in improving clinic attendance among transitioning youth with type 1 diabetes. Importantly, this programme used simple, readily accessible communication technologies, which increases the sustainability and transferability of this strategy. TRIAL REGISTRATION: isrctn.org ISRCTN13459962.

Youth with diabetes and their parents' perspectives on transition care from pediatric to adult diabetes care services: A qualitative study.

BACKGROUND AND AIMS: When youth with diabetes transition from pediatric to adult diabetes care, they are at high risk for loss to follow up and worsening glucose control. We aimed to gain insight on how to improve the transition of youth with type 1 diabetes from pediatric to adult diabetes care from the patients' and parents' perspective. METHODS: We conducted focus groups in youth with type 1 diabetes in transition from pediatric to adult diabetes care and their parents, in Calgary, Alberta, between June and August 2014. Eligibility criteria included: (a) type 1 diabetes; (b) aged 15 to 25 years; (c) have or had received care at the pediatric hospital; and, (d) either pre or post-transfer; or, (e) parents of recently transferred youth. Purposive sampling was used, and the theoretical framework used was the Integrated Behaviour Model. Participants were asked about positive, negative, or challenging experiences related to diabetes and transition, solutions to challenges, and tools and strategies to improve and better support transition. Thematic analysis was conducted after focus groups were recorded and transcribed. RESULTS: Three focus groups were conducted: pre-transfer youth with diabetes (4 females and 3 males; median age 17.5 years, IQR 1.3 years); post-transfer young adults with diabetes (2 females and 2 males; median age 23.5 years, IQR 1.2 years); and parents of recently transferred young adults with diabetes (n = 3). Main themes were: (a) communication technology; (b) the need for more transition and diabetes education and preparation during transition; and, (c) the importance and need for social and peer support. CONCLUSION: This study describes specific areas that may improve diabetes transfer and transition from pediatric to adult diabetes care. This information can help inform clinical care delivery for transition and the development of programs, strategies, and interventions to improve transition care.

Minimal navigation solution for a swarm of tiny flying robots to explore an unknown environment.

Swarms of tiny flying robots hold great potential for exploring unknown, indoor environments. Their small size allows them to move in narrow spaces, and their light weight makes them safe for operating around humans. Until now, this task has been out of reach due to the lack of adequate navigation strategies. The absence of external infrastructure implies that any positioning attempts must be performed by the robots themselves. State-of-the-art solutions, such as simultaneous localization and mapping, are still too resource demanding. This article presents the swarm gradient bug algorithm (SGBA), a minimal navigation solution that allows a swarm of tiny flying robots to autonomously explore an unknown environment and subsequently come back to the departure point. SGBA maximizes coverage by having robots travel in different directions away from the departure point. The robots navigate the environment and deal with static obstacles on the fly by means of visual odometry and wall-following behaviors. Moreover, they communicate with each other to avoid collisions and maximize search efficiency. To come back to the departure point, the robots perform a gradient search toward a home beacon. We studied the collective aspects of SGBA, demonstrating that it allows a group of 33-g commercial off-the-shelf quadrotors to successfully explore a real-world environment. The application potential is illustrated by a proof-of-concept search-and-rescue mission in which the robots captured images to find "victims" in an office environment. The developed algorithms generalize to other robot types and lay the basis for tackling other similarly complex missions with robot swarms in the future.

A personalized, multi-platform nutrition, exercise, and lifestyle coaching program: A pilot in women.

The aim of this pilot study was to examine if a personalized web-based multi-platform nutrition, exercise, and lifestyle coaching program, supported weight loss and the reduction of chronic disease risk factors in overweight or obese women. Twenty-eight women completed the program, which represented 50% of those who provided baseline data. The program consisted of a one-year curriculum with daily exercise, nutritional habits, and health behaviour lessons along with access to a one-on-one coach. The workouts, habits, and lessons were available via computer, tablet, and mobile device which, along with coaching, facilitated self-monitoring and accountability. At baseline and 12-months, weight, waist circumference, fat mass, muscle mass, blood pressure, total cholesterol, low density lipoproteins, high density lipoproteins, triglycerides, C reactive protein, and fasting glucose were collected. Over the 12 months, women who completed the program, (average age 49.64 (SD 10.99) years), lost 16.52 (SD 13.63) lbs (P < 0.001), and reduced waist circumference by 3.56 (SD 2.31) in (P < 0.0001). Diastolic blood pressure decreased by 3.77 (SD 7.25) mm Hg (P = 0.02) and high density lipoproteins increased by 0.16 (SD 0.28) mmol/L (P = 0.01). No other risk factors changed significantly. Compliance was a significant predictor of weight loss (P < 0.01). In conclusion, women who completed the web-based program experienced significant weight loss (8.62% of initial body weight) coming predominantly from body fat. Chronic disease risk factors also improved.

Responses of soil fungi to logging and oil palm agriculture in Southeast Asian tropical forests.

Human land use alters soil microbial composition and function in a variety of systems, although few comparable studies have been done in tropical forests and tropical agricultural production areas. Logging and the expansion of oil palm agriculture are two of the most significant drivers of tropical deforestation, and the latter is most prevalent in Southeast Asia. The aim of this study was to compare soil fungal communities from three sites in Malaysia that represent three of the most dominant land-use types in the Southeast Asia tropics: a primary forest, a regenerating forest that had been selectively logged 50 years previously, and a 25-year-old oil palm plantation. Soil cores were collected from three replicate plots at each site, and fungal communities were sequenced using the Illumina platform. Extracellular enzyme assays were assessed as a proxy for soil microbial function. We found that fungal communities were distinct across all sites, although fungal composition in the regenerating forest was more similar to the primary forest than either forest community was to the oil palm site. Ectomycorrhizal fungi, which are important associates of the dominant Dipterocarpaceae tree family in this region, were compositionally distinct across forests, but were nearly absent from oil palm soils. Extracellular enzyme assays indicated that the soil ecosystem in oil palm plantations experienced altered nutrient cycling dynamics, but there were few differences between regenerating and primary forest soils. Together, these results show that logging and the replacement of primary forest with oil palm plantations alter fungal community and function, although forests regenerating from logging had more similarities with primary forests in terms of fungal composition and nutrient cycling potential. Since oil palm agriculture is currently the mostly rapidly expanding equatorial crop and logging is pervasive across tropical ecosystems, these findings may have broad applicability.

Waist circumference and cardiorespiratory fitness are independently associated with glucose tolerance and insulin resistance in obese women.

The purpose of this study was to determine the independent associations between physical activity (PA), cardiorespiratory fitness (CRF), abdominal obesity and insulin action in obese women. We studied 141 abdominally obese women (waist circumference (WC): 106.4 ± 10.2 cm). PA duration (min/day) and intensity (counts/min) were obtained by accelerometry. CRF was measured using a treadmill. WC was measured at the iliac crest; abdominal adiposity was measured by magnetic resonance imaging. Glucose and insulin measures were obtained during a 75-g, 2-h glucose tolerance test. The homeostasis model of assessment iHOMA2-IS was used to estimate insulin sensitivity. PA duration and intensity were not associated with glucose or insulin metabolism (p > 0.05). However, moderate-to-vigorous PA (MVPA) duration was associated with fasting insulin and iHOMA2-IS (p < 0.01). CRF was associated with fasting insulin and iHOMA2-IS (r = 0.27, p ≤ 0.01), whereas WC was associated with fasting insulin (r = 0.50, p < 0.01) and iHOMA2-IS (r = -0.52, p ≤ 0.01). Following adjustment for CRF, MVPA, and age, WC remained associated with fasting glucose, insulin, 2-h glucose and iHOMA2-IS (r = -0.44, p ≤ 0.01). CRF was associated with fasting glucose as well as 1- and 2-h glucose (r = 0.24, p < 0.01) after adjusting for WC, MVPA, and age. MVPA was not associated with glucose or insulin measures after control for CRF and WC (p > 0.05). Mediation analysis revealed that CRF and WC combined mediated the relationship between MVPA and both glucose tolerance and insulin resistance (p < 0.05). In conclusion, among abdominally obese women, WC and CRF are independently associated with measures of glucose tolerance and insulin resistance and mediate the association between MVPA and insulin resistance.

Margin width is not predictive of residual disease on re-excision in breast conserving therapy.

BACKGROUND: There is lack of consensus regarding re-excision in breast-conserving therapy (BCT) and close margins. We hypothesize that margin width does not predict residual disease. METHODS: The cancer registry was queried from 2003 to 2008 for patients with BCT who underwent re-excision for <2-mm margins. Factors associated with additional disease were evaluated. RESULTS: One thousand eight hundred forty-three patients underwent BCT. Our re-excision rate was 42%. Clinicopathologic factors from 228 patients were analyzed. One hundred five patients (46%) had additional disease; of those, 58% had BCT and 42% mastectomy. One hundred twenty-three (54%) had no additional disease; of those 82% had BCT and 18% mastectomy. Of the 66 patients who underwent mastectomy, 44 (67%) had residual disease; of the 161 who had BCT, 61 (38%) had residual disease (P < 0.01). On univariate analysis, margin width did not correlate with residual disease. Multifocality, non-invasive histology, increasing number of close margins, and higher grade predicted additional disease (P < 0.05). On multivariate analysis, only number of close margins remained significant. CONCLUSIONS: Margin width does not predict additional disease. This challenges the practice of using this to select re-excision candidates. Our data suggest that tumor behavior and extent of disease, defined by volume of residual disease and invasiveness of histology, play a more significant role.

The importance of pre-operative needle core breast biopsy results on resected tissue volume, margin status, and cosmesis.

PURPOSE: This study aimed to evaluate the relationship between pre-operative image-guided large needle core biopsy (LNCB) histopathology results and surgical resection volumes in breast conserving surgery (BCS), with attention to both margin status and cosmetic outcome. METHODS: Breast volumes (BV) were calculated using the elliptical cone based formula on mammography images for each patient. Initial resected volume (IRV), final resected volume (FRV), and resected volume ratio (RVR) were calculated and compared according to histopathological diagnosis and cosmetic outcomes. Final pathology results were classified as benign, high risk lesion (HRL), ductal carcinoma in situ (DCIS), or invasive cancer. The cosmetic results were graded based on the Harvard breast cosmesis grading scale. RESULTS: A total of 217 women underwent BCS by the same experienced breast surgeon. The resected volumes (mean, cm3) were higher among patients who underwent LNCB than those who did not (54.3 vs 26.5 ;p=0.005). The LNCB diagnoses were 16% benign, 19% HRLs, 16% DCIS, and 49% invasive cancers. Reexcision rates were 15.6% and 25.8% for DCIS and invasive cancer, respectively. Cosmesis was excellent in 79.8%. Age, pathological tumor size, IRV and FRV were different among the benign, HRLs and carcinoma groups (p= 0.001). CONCLUSION: The diagnosis of carcinoma by LNCB leads to the planning of a wider resection, but the need for reexcision is no different than less resection. HRLs are best approached with diagnostic excision, as there is no strong evidence that larger resections reduce the incidence of involved resection margins.

Acute exercise increases adiponectin levels in abdominally obese men.

Objective. To examine the effect of acute and short-term (~1 week) aerobic exercise training on plasma adiponectin levels in inactive, abdominally obese men. Materials and Methods. Inactive and abdominally obese men (n = 38, waist circumference ≥102 cm) recruited from Kingston, Canada were randomly allocated to perform three bouts of aerobic treadmill exercise at either low (50% VO(2) peak) or high (75% VO(2) peak) intensity during a 1-week period. Blood samples were taken before and after the first exercise session and 24-72 hours following the completion of the final exercise session. Results. Adiponectin levels were elevated immediately following an acute bout of exercise at both high and low intensities (High: 5.79 ± 0.42 versus 5.05 ± 0.41 ug/mL; Low: 5.24 ± 0.44 versus 4.37 ± 0.44 ug/mL, P < 0.05) and remained elevated following 30 minutes of rest. In comparison to baseline, adiponectin levels were also elevated 24-72 hours following the final exercise session (High: 5.47 ± 0.48 versus 4.88 ± 0.48 ug/mL; Low: 5.18 ± 0.49 versus 4.47 ± 0.49 ug/mL, P < 0.05). Conclusion. Both acute and short-term aerobic exercise result in a significant increase in plasma adiponectin levels in inactive, abdominally obese men independent of intensity.

Incidental physical activity and sedentary behavior are not associated with abdominal adipose tissue in inactive adults.

The aim was to determine the association between objectively measured incidental physical activity (IPA) (i.e.,nonpurposeful activity accrued through activities of daily living) and sedentary behavior (SED) with abdominal obesity in a sample of inactive men and women. Participants were inactive, abdominally obese men (n = 42; waist circumference (WC) ≥102 cm) and women (n = 84; WC ≥88 cm) recruited from Kingston, Canada. Physical activity and SED were determined by accelerometry over 7 days and summarized as IPA (accelerometer counts per min (cpm) >100), light physical activity (LPA; cpm 100-1951), sporadic moderate-to-vigorous physical activity (MVPA; cpm ≥1,952, accumulated in bouts <10 consecutive minutes) and SED (cpm <100). Magnetic resonance imaging was used to acquire measures of abdominal obesity, visceral adipose tissue (VAT), and subcutaneous adipose tissue (ASAT). Participants spent on average 310.2 ± 102.6 min/d in IPA and 627.8 ± 86.9 min/d in SED. Neither IPA nor SED was associated with any measure of abdominal obesity (P > 0.1). Similarly, LPA was not a significant predictor of abdominal obesity whereas sporadic MVPA was negatively associated with VAT (P < 0.05) after control for age and sex. In this study, neither IPA nor SED was associated with abdominal obesity among inactive men and women.

Cardiorespiratory fitness, obesity, and functional limitation in older adults.

One hundred forty-six abdominally obese adults age 60-80 yr were studied to investigate the interaction between cardiorespiratory fitness (CRF) and obesity on functional limitation. Obesity was determined by fat mass (FM), CRF was determined by a maximal treadmill test, and functional limitation was based on 4 different tasks that are predictive of subsequent disability. Both FM (r = -.34, p ≤ .01) and CRF (r = .54, p ≤ .01) were independently associated with functional limitation in bivariate analysis.After further control for sex, age, and the interaction term (CRF × FM), FM was no longer independently associated with functional limitation (p = .10). Analyses were also based on sex-specific tertiles of FM and CRF. The referent group demonstrated significantly lower functional limitation than the low-CRF/low-FM and the low-CRF/high-FM groups (both p ≤ .05). These results highlight the value of recommending exercise for abdominally obese adults.

Sedentary behavior is not associated with cardiometabolic risk in adults with abdominal obesity.

OBJECTIVE: The primary aim of this study was to determine whether time spent in sedentary behaviors (SED) was associated with 2-hour glucose and insulin resistance in adults with abdominal obesity. We also examined the association between light physical activity (LPA) and sporadic (accumulated in bouts <10 minutes in duration) moderate-to-vigorous physical activity (MVPA) with glucose metabolism. METHODS: Participants were 135 inactive, abdominally obese adults recruited from Kingston, Canada. SED and physical activity were determined by accelerometry over 7 days and summarized as SED (accelerometer counts/min <100), LPA (counts/min 100-1951), and MVPA (counts/min ≥1952). A 75 g oral glucose tolerance test was used to ascertain 2-hour glucose; the homeostasis model of assessment was used to determine insulin resistance (HOMA-IR); lipid, lipoproteins and blood pressure were determined using standard protocols. Secondary analyses considered the association between SED and physical activity with other cardiometabolic risk factors. RESULTS: Participants spent 627.2±82.9 min/d in SED, 289.0±91.7 min/d in LPA and 19.2±13.5 min/d in MVPA. Neither SED nor the physical activity variables were associated with 2-hour glucose or HOMA-IR (p>0.05). In secondary analyses, SED was not associated with any cardiometabolic risk factor (p>0.1); with the exception of blood pressure (p<0.05), LPA was not associated with any cardiometabolic risk factor (p>0.1); and MVPA was independently associated with total cholesterol and triglycerides (p<0.05). CONCLUSIONS: Objectively measured SED was not associated with 2-hr glucose or HOMA-IR. Our findings also suggest that the accumulation of LPA and sporadic MVPA is not associated with glucose metabolism in adults with abdominal obesity.

Incidental physical activity is positively associated with cardiorespiratory fitness.

PURPOSE: The primary aim was to determine whether incidental physical activity (IPA), expressed either as duration or intensity, was associated with cardiorespiratory fitness (CRF). METHODS: Participants were inactive abdominally obese men (n = 43, waist circumference ≥ 102 cm) and women (n = 92, waist circumference ≥ 88 cm) recruited from Kingston, Canada. IPA (>100 counts per minute) was determined by accelerometry during 7 d and categorized into duration (min·d(-1)) and intensity (counts per minute). In secondary analyses, IPA was further categorized as light physical activity (LPA, 100-1951 counts per minute) and sporadic moderate physical activity (MPA, ≥ 1952 counts per minute accumulated in bouts <10 consecutive minutes). CRF was assessed using a maximal treadmill exercise test. RESULTS: Participants accumulated 308.2 ± 98.8 (mean ± SD) min of IPA per day of which 19.2 ± 13.5 min was spent in sporadic MPA. Mean CRF was 26.8 ± 4.7 mL·kg(-1) body weight·min(-1). IPA duration was positively associated with CRF in the univariate model (r2 = 0.03, P < 0.05) and after control for gender and body mass index (r2 = 0.53, P < 0.01). Likewise, IPA intensity was positively associated with CRF in univariate (r2 = 0.18, P < 0.001) and multivariate analyses (r2 = 0.56, P < 0.01). After further control for each other, IPA duration was not associated with CRF (P = 0.05), whereas IPA intensity remained a significant predictor (r2 = 0.57, P < 0.001). In secondary analyses, LPA was not associated with CRF (P > 0.05). Sporadic MPA was associated with CRF (r2 = 0.20, P < 0.001) and remained a positive correlate after control for gender, body mass index, and the other physical activity variables (r2 = 0.60, P < 0.001). CONCLUSIONS: In this study, both duration and intensity of IPA were positively associated with CRF among inactive abdominally obese adults. Sporadic MPA, but not LPA, was an independent predictor of CRF.

Adenovirus membrane penetration activates the NLRP3 inflammasome.

Adenovirus type 5 (Ad5) infection of macrophages results in rapid secretion of interleukin-1ß (IL-1ß) and is dependent on the inflammasome components NLRP3 and ASC and the catalytic activity of caspase-1. Using lentivirus-expressed short hairpin RNA (shRNA) and competitive inhibitors, we show that Ad-induced IL-1ß release is dependent upon Toll-like receptor 9 (TLR9) sensing of the Ad5 double-stranded DNA (dsDNA) genome in human cell lines and primary monocyte-derived macrophages but not in mouse macrophages. Additionally, a temperature-sensitive mutant of Ad5 unable to penetrate endosomal membranes, ts1, is unable to induce IL-1ß release in TLR2-primed THP-1 cells, suggesting that penetration of endosomal membranes is required for IL-1ß release. Disruption of lysosomal membranes and the release of cathepsin B into the cytoplasm are required for Ad-induced NLRP3 activation. Ad5 cell entry also induces reactive oxygen species (ROS) production, and inhibitors of ROS prevent Ad-induced IL-1ß release. Ad5 activation of NLRP3 also induces necrotic cell death, resulting in the release of the proinflammatory molecule HMGB1. This work further defines the mechanisms of virally induced inflammasome activation.

The challenge of low physical activity during the school day: at recess, lunch and in physical education.

PURPOSE: To describe physical activity (PA) intensity across a school day and assess the percentage of girls and boys achieving recommended guidelines. METHODS: The authors measured PA via accelerometry in 380 children (8-11 years) and examined data representing (1) the whole school day, (2) regular class time, (3) recess, (4) lunch and (5) scheduled physical education (PE). Activity was categorised as sedentary (SED), light physical activity (LPA) or moderate to vigorous physical activity (MVPA) using age-specific thresholds. They examined sex differences across PA intensities during each time period and compliance with recommended guidelines. RESULTS: Girls accumulated less MVPA and more SED than boys throughout the school day (MVPA -10.6 min; SED +13.9 min) recess (MVPA -1.6 min; SED +1.7 min) and lunch (MVPA -3.1 min; SED +2.9 min). Girls accumulated less MVPA (-6.2 min), less LPA (-2.5 min) and more SED (+9.4 min) than boys during regular class time. Fewer girls than boys achieved PA guidelines during school (90.9% vs 96.2%), recess (15.7% vs 34.1%) and lunch (16.7% vs 37.4%). During PE, only 1.8% of girls and 2.9% of boys achieved the PA guidelines. Girls and boys accumulated similar amounts of MVPA, LPA and SED. CONCLUSION: The MVPA deficit in girls was due to their sedentary behaviour as opposed to LPA. Physical activity strategies that target girls are essential to overcome this deficit. Only a very small percentage of children met physical activity guidelines during PE. There is a great need for additional training and emphasis on PA during PE. In addition schools should complement PE with PA models that increase PA opportunities across the school day.

Ability of physical activity to predict cardiovascular disease beyond commonly evaluated cardiometabolic risk factors.

It is well-established that increasing physical activity (PA) is important for the prevention and management of cardiovascular disease (CVD). Although it has been demonstrated that PA predicts CVD independent of commonly measured cardiometabolic risk factors in women, it is unclear whether this association is true in men. The study participants consisted of 5,882 adults (age >or=18 years) from the 1999 to 2004 United States National Health and Nutrition Examination Survey. Blood pressure, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, glucose, and waist circumference were categorized using standard clinical thresholds. The participants were divided into the following groups according to the volume of their moderate-to-vigorous intensity PA: active (>or=150 min/wk), somewhat active (30 to 149 min/wk), and inactive (<30 min/wk). Logistic regression analyses were used to calculate the odds ratios for CVD according to PA. After controlling for the basic confounders (age, gender, race, smoking), inactive participants were 52% (95% confidence interval 16% to 98%) more likely than the active participants to have CVD. Additional adjustment for cardiometabolic risk factors did not change the odds ratio for CVD in the inactive group. To further delineate the effects of PA on CVD, the participants were cross-classified according to their PA level and their number of cardiometabolic risk factors. Both PA and cardiometabolic risk factors were independent predictors of CVD (P(trend) <0.0001). The results were not modified by gender. In conclusion, PA was associated with CVD, independent of the common cardiometabolic risk factors, in men and women. The association between PA and CVD risk was not mediated by the measured cardiometabolic risk factors.

Cardiorespiratory fitness and the risk of overweight in youth: the Healthy Hearts Longitudinal Study of Cardiometabolic Health.

The primary objective of this longitudinal study was to determine the association between cardiorespiratory fitness and the risk of overweight status in youth. To accomplish this aim we analyzed data from annual school-based surveys of cardiorespiratory fitness and anthropometry conducted between 2004 and 2006. The first analysis was performed on a cohort of 902 youth aged 6-15 years followed for 12 months to assess the association between cardiorespiratory fitness levels determined from a graded maximal field test and the risk of becoming overweight. The second analysis was conducted on a cohort of 222 youth followed for 2 years to assess the continuous association between annual changes fitness and weight gain. Children with low cardiorespiratory fitness were characterized by higher waist circumference and disproportionate weight gain over the 12-month follow-up period (P < 0.05). Within the entire cohort, the 12-month risk of overweight classification was 3.5-fold (95% confidence = 2.0-6.0, P < 0.001) higher in youth with low cardiorespiratory fitness, relative to fit peers. A time series mixed effects regression model revealed that reductions in cardiorespiratory fitness were significantly and independently associated with increasing BMI (r = -0.18, P < 0.05) in youth. Accordingly, low cardiorespiratory fitness and reductions in fitness over time are significantly associated with weight gain and the risk of overweight in children 6-15 years old. An assessment of cardiorespiratory fitness using a common field test may prove useful for the identification of youth at risk of overweight and serve as a potential target for obesity prevention.

Dual mycorrhizal colonization of forest-dominating tropical trees and the mycorrhizal status of non-dominant tree and liana species.

The contribution of mycorrhizal associations to maintaining tree diversity patterns in tropical rain forests is poorly known. Many tropical monodominant trees form ectomycorrhizal (EM) associations, and there is evidence that the EM mutualism contributes to the maintenance of monodominance. It is assumed that most other tropical tree species form arbuscular mycorrhizal (AM) associations, and while many mycorrhizal surveys have been done, the mycorrhizal status of numerous tropical tree taxa remains undocumented. In this study, we tested the assumption that most tropical trees form AM associations by sampling root vouchers from tree and liana species in monodominant Dicymbe corymbosa forest and an adjacent mixed rain forest in Guyana. Roots were assessed for the presence/ absence of AM and EM structures. Of the 142 species of trees and lianas surveyed, three tree species (the mono-dominant D. corymbosa, the grove-forming D. altsonii, and the non-dominant Aldina insignis) were EM, 137 were exclusively AM, and two were non-mycorrhizal. Both EM and AM structures wer e observed in D. corymbosa and D. altsonii. These results provide empirical data supporting the assumption that most tropical trees form AM associations for this region in the Guiana Shield and provide the first report of dual EM/AM colonization in Dicymbe species. Dual colonization of the Dicymbe species should be further explored to determine if this ability contributes to the establishment and maintenance of site dominance.