Short-term HIIT and Fatmax training increase aerobic and metabolic fitness in men with class II and III obesity.

OBJECTIVE: To compare the effects of two different 2-week-long training modalities [continuous at the intensity eliciting the maximal fat oxidation (Fatmax ) versus high-intensity interval training (HIIT)] in men with class II and III obesity. METHODS: Nineteen men with obesity (BMI ≥ 35 kg(.) m(-2) ) were assigned to Fatmax group (GFatmax ) or to HIIT group (GHIIT ). Both groups performed eight cycling sessions matched for mechanical work. Aerobic fitness and fat oxidation rates (FORs) during exercise were assessed prior and following the training. Blood samples were drawn to determine hormones and plasma metabolites levels. Insulin resistance was assessed by the homeostasis model assessment of insulin resistance (HOMA2-IR). RESULTS: Aerobic fitness and FORs during exercise were significantly increased in both groups after training (P ≤ 0.001). HOMA2-IR was significantly reduced only for GFatmax (P ≤ 0.001). Resting non-esterified fatty acids (NEFA) and insulin decreased significantly only in GFatmax (P ≤ 0.002). CONCLUSIONS: Two weeks of HIIT and Fatmax training are effective for the improvement of aerobic fitness and FORs during exercise in these classes of obesity. The decreased levels of resting NEFA only in GFatmax may be involved in the decreased insulin resistance only in this group.

How patient-centered do female physicians need to be? Analogue patients' satisfaction with male and female physicians' identical behaviors (Published online: 30 Aug 2014)

Previous research suggests that female physicians may not receive appropriate credit in patients' eyes for their patient-centered skills compared to their male counterparts. An experiment was conducted to determine whether a performance of higher (versus lower) verbal patient-centeredness would result in a greater difference in analogue patient satisfaction for male than female physicians. Two male and two female actors portrayed physicians speaking to a patient using high or low patient-centered scripts while not varying their nonverbal cues. One hundred ninety-two students served as analogue patients by assuming the patient role while watching one of the videos and rating their satisfaction and other evaluative responses to the physician. Greater verbal patient-centeredness had a stronger positive effect on satisfaction and evaluations for male than for female physicians. This pattern is consistent with the hypothesis that the different associations between patient-centeredness and patients' satisfaction for male versus female physicians occur because of the overlap between stereotypical female behavior and behaviors that comprise patient-centered medical care. If this is the case, high verbal patient-centered behavior by female physicians is not recognized as a marker of clinical competence, as it is for male physicians, but is rather seen as expected female behavior.

Asymmetrical nature of the Trollius-Chiastocheta interaction: insights into the evolution of nursery pollination systems

The mutualistic versus antagonistic nature of an interaction is defined by costs and benefits of each partner, which may vary depending on the environment. Contrasting with this dynamic view, several pollination interactions are considered as strictly obligate and mutualistic. Here, we focus on the interaction between Trollius europaeus and Chiastocheta flies, considered as a specialized and obligate nursery pollination system - the flies are thought to be exclusive pollinators of the plant and their larvae develop only in T.europaeus fruits. In this system, features such as the globelike flower shape are claimed to have evolved in a coevolutionary context. We examine the specificity of this pollination system and measure traits related to offspring fitness in isolated T.europaeus populations, in some of which Chiastocheta flies have gone extinct. We hypothesize that if this interaction is specific and obligate, the plant should experience dramatic drop in its relative fitness in the absence of Chiastocheta. Contrasting with this hypothesis, T.europaeus populations without flies demonstrate a similar relative fitness to those with the flies present, contradicting the putative obligatory nature of this pollination system. It also agrees with our observation that many other insects also visit and carry pollen among T.europaeus flowers. We propose that the interaction could have evolved through maximization of by-product benefits of the Chiastocheta visits, through the male flower function, and selection on floral traits by the most effective pollinator. We argue this mechanism is also central in the evolution of other nursery pollination systems.

Les étudiant(e)s en médecine mènent une recherche dans La communauté [Male/female medical students conduct research in the community].

Pendant quatre semaines, les étudiant(e)s en médecine de 3e année de l'Université de Lausanne mènent une enquête dans la communauté sur le sujet de leur choix. L'objectif de ce module est de faire découvrir aux futurs médecins les déterminants non biomédicaux de la santé, de la maladie et de l'exercice de la médecine : les styles de vie, les facteurs psychosociaux et culturels, l'environnement, les décisions politiques, les contraintes économiques, les questions éthiques, etc. Par groupes de cinq, les étudiant(e)s commencent par définir une question de recherche originale et en explorent la littérature scientifique. Leur travail de recherche les amène à entrer en contact avec le réseau d'acteurs de la communauté concernés, professionnels ou associations de patients dont ils analysent les rôles et influences respectives. Chaque groupe est accompagné par un(e) tuteur(trice), enseignant(e) de la Faculté de biologie et de médecine de l'Université de Lausanne. Les étudiant(e)s présentent la synthèse de leurs travaux pendant un congrès de deux jours à la fin du module. Quatre travaux parmi les plus remarquables ont été choisis pour être publiés dans la Revue Médicale Suisse et Primary Care.

Drosophila Ionotropic Receptor 25a mediates circadian clock resetting by temperature.

Circadian clocks are endogenous timers adjusting behaviour and physiology with the solar day. Synchronized circadian clocks improve fitness and are crucial for our physical and mental well-being. Visual and non-visual photoreceptors are responsible for synchronizing circadian clocks to light, but clock-resetting is also achieved by alternating day and night temperatures with only 2-4 °C difference. This temperature sensitivity is remarkable considering that the circadian clock period (~24 h) is largely independent of surrounding ambient temperatures. Here we show that Drosophila Ionotropic Receptor 25a (IR25a) is required for behavioural synchronization to low-amplitude temperature cycles. This channel is expressed in sensory neurons of internal stretch receptors previously implicated in temperature synchronization of the circadian clock. IR25a is required for temperature-synchronized clock protein oscillations in subsets of central clock neurons. Extracellular leg nerve recordings reveal temperature- and IR25a-dependent sensory responses, and IR25a misexpression confers temperature-dependent firing of heterologous neurons. We propose that IR25a is part of an input pathway to the circadian clock that detects small temperature differences. This pathway operates in the absence of known 'hot' and 'cold' sensors in the Drosophila antenna, revealing the existence of novel periphery-to-brain temperature signalling channels.

Association of Hematological Variables with Team-Sport Specific Fitness Performance.

PURPOSE: We investigated association of hematological variables with specific fitness performance in elite team-sport players. METHODS: Hemoglobin mass (Hbmass) was measured in 25 elite field hockey players using the optimized (2 min) CO-rebreathing method. Hemoglobin concentration ([Hb]), hematocrit and mean corpuscular hemoglobin concentration (MCHC) were analyzed in venous blood. Fitness performance evaluation included a repeated-sprint ability (RSA) test (8 x 20 m sprints, 20 s of rest) and the Yo-Yo intermittent recovery level 2 (YYIR2). RESULTS: Hbmass was largely correlated (r = 0.62, P<0.01) with YYIR2 total distance covered (YYIR2TD) but not with any RSA-derived parameters (r ranging from -0.06 to -0.32; all P>0.05). [Hb] and MCHC displayed moderate correlations with both YYIR2TD (r = 0.44 and 0.41; both P<0.01) and RSA sprint decrement score (r = -0.41 and -0.44; both P<0.05). YYIR2TD correlated with RSA best and total sprint times (r = -0.46, P<0.05 and -0.60, P<0.01; respectively), but not with RSA sprint decrement score (r = -0.19, P>0.05). CONCLUSION: Hbmass is positively correlated with specific aerobic fitness, but not with RSA, in elite team-sport players. Additionally, the negative relationships between YYIR2 and RSA tests performance imply that different hematological mechanisms may be at play. Overall, these results indicate that these two fitness tests should not be used interchangeably as they reflect different hematological mechanisms.

Subjective perceptions as prognostic factors of time to fitness for work during a 4-year period after inpatient rehabilitation for orthopaedic trauma.

INTRODUCTION: Time to fitness for work (TFW) was measured as the number of days that were paid as compensation for work disability during the 4 years after discharge from the rehabilitation clinic in a population of patients hospitalised for rehabilitation after orthopaedic trauma. The aim of this study was to test whether some psychological variables can be used as potential early prognostic factors of TFW. MATERIAL AND METHODS: A Cox proportional hazards model was used to estimate the associations between predictive variables and TFW. Predictors were global health, pain at hospitalisation and pain decrease during the stay (all continuous and standardised by subtracting the mean and dividing by two standard deviations), perceived severity of the trauma and expectation of a positive evolution (both binary variables). RESULTS: Full data were available for 807 inpatients (660 men, 147 women). TFW was positively associated with better perceived health (hazard ratio [HR] 1.16, 95% confidence interval [CI] 1.13-1.19), pain decrease (HR 1.46, 95% CI 1.30-1.64) and expectation of a positive evolution (HR 1.50, 95% CI 1.32-1.70) and negatively associated with pain at hospitalisation (HR 0.67, 95% CI 0.59-0.76) and high perceived severity (HR 0.72, 95% CI 0.61-0.85). DISCUSSION: The present results provide some evidence that work disability during a four-year period after rehabilitation may be predicted by prerehabilitation perceptions of general health, pain, injury severity, as well as positive expectation of evolution.

Sex ratio bias, male aggression, and population collapse in lizards.

The adult sex ratio (ASR) is a key parameter of the demography of human and other animal populations, yet the causes of variation in ASR, how individuals respond to this variation, and how their response feeds back into population dynamics remain poorly understood. A prevalent hypothesis is that ASR is regulated by intrasexual competition, which would cause more mortality or emigration in the sex of increasing frequency. Our experimental manipulation of populations of the common lizard (Lacerta vivipara) shows the opposite effect. Male mortality and emigration are not higher under male-biased ASR. Rather, an excess of adult males begets aggression toward adult females, whose survival and fecundity drop, along with their emigration rate. The ensuing prediction that adult male skew should be amplified and total population size should decline is supported by long-term data. Numerical projections show that this amplifying effect causes a major risk of population extinction. In general, such an "evolutionary trap" toward extinction threatens populations in which there is a substantial mating cost for females, and environmental changes or management practices skew the ASR toward males.

Fat oxidation over a range of exercise intensities: fitness versus fatness.

Maximal fat oxidation (MFO), as well as the exercise intensity at which it occurs (Fatmax), have been reported as lower in sedentary overweight individuals but have not been studied in trained overweight individuals. The aim of this study was to compare Fatmax and MFO in lean and overweight recreationally trained males matched for cardiorespiratory fitness (CRF) and to study the relationships between these variables, anthropometric characteristics, and CRF. Twelve recreationally trained overweight (high fatness (HiFat) group, 30.0% ± 5.3% body fat) and 12 lean males (low fatness (LoFat), 17.2% ± 5.7% body fat) matched for CRF (maximal oxygen consumption (V̇O2max) 39.0 ± 5.5 vs. 41.4 ± 7.6 mL·kg(-1)·min(-1), p = 0.31) and age (p = 0.93) performed a graded exercise test on a cycle ergometer. V̇O2max and fat and carbohydrate oxidation rates were determined using indirect calorimetry; Fatmax and MFO were determined with a mathematical model (SIN); and % body fat was assessed by air displacement plethysmography. MFO (0.38 ± 0.19 vs. 0.42 ± 0.16 g·min(-1), p = 0.58), Fatmax (46.7% ± 8.6% vs. 45.4% ± 7.2% V̇O2max, p = 0.71), and fat oxidation rates over a wide range of exercise intensities were not significantly different (p > 0.05) between HiFat and LoFat groups. In the overall cohort (n = 24), MFO and Fatmax were correlated with V̇O2max (r = 0.46, p = 0.02; r = 0.61, p = 0.002) but not with % body fat or body mass index (p > 0.05). Fat oxidation during exercise was similar in recreationally trained overweight and lean males matched for CRF. Consistently, substrate oxidation rates during exercise were not related to adiposity (% body fat) but were related to CRF. The benefits of high CRF independent of body weight and % body fat should be further highlighted in the management of obesity.

Local effects drive heterozygosity-fitness correlations in an outcrossing long-lived tree.

Heterozygosity-fitness correlations (HFCs) have been used to understand the complex interactions between inbreeding, genetic diversity and evolution. Although frequently reported for decades, evidence for HFCs was often based on underpowered studies or inappropriate methods, and hence their underlying mechanisms are still under debate. Here, we used 6100 genome-wide single nucleotide polymorphisms (SNPs) to test for general and local effect HFCs in maritime pine (Pinus pinaster Ait.), an iconic Mediterranean forest tree. Survival was used as a fitness proxy, and HFCs were assessed at a four-site common garden under contrasting environmental conditions (total of 16 288 trees). We found no significant correlations between genome-wide heterozygosity and fitness at any location, despite variation in inbreeding explaining a substantial proportion of the total variance for survival. However, four SNPs (including two non-synonymous mutations) were involved in significant associations with survival, in particular in the common gardens with higher environmental stress, as shown by a novel heterozygosity-fitness association test at the species-wide level. Fitness effects of SNPs involved in significant HFCs were stable across maritime pine gene pools naturally growing in distinct environments. These results led us to dismiss the general effect hypothesis and suggested a significant role of heterozygosity in specific candidate genes for increasing fitness in maritime pine. Our study highlights the importance of considering the species evolutionary and demographic history and different spatial scales and testing environments when assessing and interpreting HFCs.

Experimental enhancement of corticosterone levels positively affects subsequent male survival.

Corticosterone is an important hormone of the stress response that regulates physiological processes and modifies animal behavior. While it positively acts on locomotor activity, it may negatively affect reproduction and social activity. This suggests that corticosterone may promote behaviors that increase survival at the cost of reproduction. In this study, we experimentally investigate the link between corticosterone levels and survival in adult common lizards (Lacerta vivipara) by comparing corticosterone-treated with placebo-treated lizards. We experimentally show that corticosterone enhances energy expenditure, daily activity, food intake, and it modifies the behavioral time budget. Enhanced appetite of corticosterone-treated individuals compensated for increased energy expenditure and corticosterone-treated males showed increased survival. This suggests that corticosterone may promote behaviors that reduce stress and it shows that corticosterone per se does not reduce but directly or indirectly increases longer-term survival. This suggests that the production of corticosterone as a response to a stressor may be an adaptive mechanism that even controls survival.

Troubles du comportement alimentaire (TCA), sports de remise en forme et motivations de pratique = Fitness sports, sport motives and eating disorders

Cet article a pour but d'identifier et de mieux comprendre les liens entre les motivations des pratiquantes de sports de remise en forme, les troubles du comportement alimentaire (TCA) et les troubles psychologiques associés (i.e., insatisfaction corporelle, dépendance à l'exercice physique). Au total, 1270 pratiquantes ont répondu à un questionnaire et 40 ont participé à un entretien semi-directif. Les motivations de perte de poids et/ou modification de l'apparence corporelle sont en lien avec les TCA et l'insatisfaction corporelle. La dépendance à l'exercice physique n'est pas systématique chez les femmes avec TCA. Les pratiquantes de sports de remise en forme motivées uniquement par la perte de poids et/ou la modification de l'apparence sont plus à risques dans levdéveloppement des TCA. The aim of this study was to identify and to better understand links between females' motives in fitness sports, eating disorders (ED) and associated psychological disorders (i.e. body dissatisfaction, exercise dependence). In all, 1270 women were asked by questionnaire and 40 by semi-structured interview. Weight loss/body appearance change motives are related to ED and body dissatisfaction. Exercise dependence are not systematic in women with ED. Fitness sports are at risk in the development of ED for women motivated only by weight loss/body appearance change motives

"Vedo il male e non lo posso schivare" : le rime di Antonio Brocardo tra classicismi e polemiche

Antonio Brocardo è ricordato per essere entrato in polemica con Pietro Bembo, suscitando clamore e indignazione. Le fonti antiche sulla vita del Bembo lo descrivono come un folle intento a distruggere qualcosa che non riusciva bene a comprendere Vitaliani lo definisce, nel titolo della sua monografia del 1902 (l'unica fino ad ora dedicata al poeta), «vittima del bembismo», probabilmente risentendo dei pesanti giudizi sul cardinale già presenti in Leopardi e poi nel De Sanctis. Eppure, già a partire da Croce, si cerca di ricostruire in maniera meno pregiudizievole la figura del poeta veneziano, considerando più da vicino i testi pervenuti. Ci si trova, però, di fronte ad uno scarto imponente: la tradizione lo vuole opposto al bembismo, mentre la lirica brocardiana non sembra per molti aspetti differenziarsi così platealmente dal canone bembesco, a giudizio di molte storie letterarie. Questa nuova edizione mira: a ricostruire scrupolosamente la biografia del poeta, l'ambiente frequentato ed i rapporti con altri poeti/intellettuali del suo tempo; a fare finalmente chiarezza sulle polemiche che videro il giovane veneziano come protagonista, a partire dalle fonti contemporanee (correggendo quanto riportato dalle biografìe del Bembo o dalle storie letterarie); a fornire un adeguato commento alle sue rime, dopo aver ristabilito un sicuro testo critico; a fare maggior chiarezza sul rapporto tra Brocardo ed il furbesco letterario; a collocare il poeta in una ben determinata fase del petrarchismo.