Risk reduction strategies in Branchipus schaefferi (Crustacea: Anostraca: Branchiopoda) as adaptation to a variable environment

Mud from a temporary pool in Morocco was sequentially inundated and dried at the laboratory to follow the life history of Branchipus schaefferi. Once adult, each female was coupled to a male in order to study their life history and reproduction. The average percentage of hatching decreased during the successive inundations, presumably as an adaptation to the unpredictability of the habitat. However, there was no indication that the offspring of the first inundation would preferentially hatch during their first inundation too, neither was there any such preference in the offspring of the delayed hatchings. Each female reduced risk by spreading hatching time of her resting eggs over consecutive inundations. Eggs did not hatch all at the same moment, reducing the chance that a female's entire offspring would die before reaching maturity if the pool would dry out too soon. There was a significant difference between the mean value of the number of resting eggs produced by the females from a large clutch size, and those produced by females from a small clutch size. There thus appears to be a genetic base for the clutch size of females

Independent associations between sedentary time, moderate-to-vigorous physical activity, cardiorespiratory fitness and cardio-metabolic health : a cross-sectional study

We aimed to study the independent associations of sedentary time (ST), moderate-to-vigorous physical activity (MVPA), and objectively measured cardiorespiratory fitness (CRF) with clustered cardio-metabolic risk and its individual components (waist circumference, fasting glucose, HDL-cholesterol, triglycerides and blood pressure). We also investigated whether any associations between MVPA or ST and clustered cardio-metabolic risk were mediated by CRF. MVPA, ST, CRF and individual cardio-metabolic components were measured in a population-based sample of 341 adults (age 53.8 +/- 8.9 years; 61% men) between 2012 and 2014. MVPA and ST were measured with the SenseWear pro 3 Armband and CRF was measured with a maximal exercise test. Multiple linear regression models and the product of coefficients method were used to examine independent associations and mediation effects, respectively. Results showed that low MVPA and low CRF were associated with a higher clustered cardio-metabolic risk (beta = -0.26 and beta = -0.43, both p<0.001, respectively). CRF explained 73% of the variance in the association between MVPA and clustered cardio-metabolic risk and attenuated this association to non-significance. After mutual adjustment for MVPA and ST, CRF was the most important risk factor for a higher clustered cardio-metabolic risk (beta = -0.39, p<0.001). In conclusion, because of the mediating role of CRF, lifestyle-interventions need to be feasible yet challenging enough to lead to increases in CRF to improve someone's cardio-metabolic health

Longitudinal study on the association between three dietary indices, anthropometric parameters and blood lipids

Background: From a health promotion perspective, the use of dietary indices is preferred above single nutrients and foods to evaluate diet quality. Longitudinal research about the association between dietary indices and respectively anthropometric parameters and blood lipids is lacking. The aim of this study was to investigate the longitudinal association between three dietary indices (Healthy Eating Index-2010 (HEI), Mediterranean Diet Score (MDS) and Diet Quality Index (DQI)) and respectively anthropometric parameters and blood lipids. Methods: A three day diet record was completed by 373 men and 197 women in 2002-2004 and 2012-2014. HEI, MDS and DQI were calculated. Waist circumference (WC) and Body Mass Index (BMI) were used as anthropometric parameters. A linear regression analysis was performed to investigate associations between changes in dietary indices and changes in respectively anthropometric parameters and blood lipids, adjusted for potential confounders. Results: Only in men an increase in all three dietary indices was associated with a decrease in WC and BMI in the non-adjusted analysis and for HEI and DQI also in the adjusted analysis. No longitudinal associations were found between dietary indices and blood lipids both in men and women. Conclusions: Only few associations were found between dietary indices and anthropometric parameters, whilst no associations were found with blood lipids. An increase in dietary indices was associated with an improvement in anthropometric parameters only in men. As this is the first study investigating associations between changes in dietary indices and changes in respectively anthropometric parameters and blood lipids, further research is needed to evaluate these possible associations

Longitudinal study on the association between cardiorespiratory fitness, anthropometric parameters and blood lipids

Background: Longitudinal evidence concerning the association between cardiorespiratory fitness (CRF) and blood lipids and between anthropometric parameters (ANTP) and blood lipids is limited. This study aimed to investigate the association between changes in CRF and ANTP and changes in blood lipids. Methods: In 2002-2004 and 2012-2014,652 participants were tested. CRF was measured as VO(2)peak using a maximal ergometer test. Waist circumference (WC) and Body Mass Index (BMI) were used as ANTP. Blood samples were analyzed for total cholesterol (TC), HDL cholesterol, LDL cholesterol and triglycerides. A linear regression analysis was performed to investigate associations between changes in CRF and ANTP and changes in blood lipids. Results: After adjustment a decrease in CRF was associated with an increase in triglycerides and a decrease in HDL cholesterol in men. An increase in WC was associated with an increase in TC, LDL cholesterol and ratio total/HDL cholesterol and a decrease in HDL cholesterol, while an increase in BMI was associated with an increase in ratio total/HDL cholesterol and a decrease in HDL cholesterol. Conclusions: WC and BMI were more longitudinally associated with blood lipids compared with CRF. Improving ANTP can enhance the blood lipid profile, while CRF had only limited influence

Differences in the chemical composition of organic-walled dinoflagellate resting cysts from phototrophic and heterotrophic dinoflagellates

Dinoflagellates constitute a large proportion of the planktonic biomass from marine to freshwater environments. Some species produce a preservable organic-walled resting cyst (dinocyst) during the sexual phase of their life cycle that is an important link between the organisms, the environment in which their parent motile theca grew, and the sedimentary record. Despite their abundance and widespread usage as proxy indicators for environmental conditions, there is a lack of knowledge regarding the dinocyst wall chemical composition. It is likely that numerous factors, including phylogeny and life strategy, determine the cyst wall chemistry. However, the extent to which this composition varies based on inherent (phylogenetic) or variable (ecological) factors has not been studied. To address this, we used micro-Fourier transform infrared spectroscopy to analyze nine cyst species produced by either phototrophic or heterotrophic dinoflagellates from the extant orders Gonyaulacales, Gymnodiniales, and Peridiniales. Based on the presence of characteristic functional groups, two significantly different cyst wall compositions are observed that correspond to the dinoflagellate's nutritional strategy. The dinocyst wall compositions analyzed appeared carbohydrate-based, but the cyst wall produced by phototrophic dinoflagellates suggested a cellulose-like glucan, while heterotrophic forms produced a nitrogen-rich glycan. This constitutes the first empirical evidence nutritional strategy is related to different dinocyst wall chemistries. Our results indicated phylogeny was less important for predicting composition than the nutritional strategy of the dinoflagellate, suggesting potential for cyst wall chemistry to infer past nutritional strategies of extinct taxa preserved in the sedimentary record

The importance of feeding status and desiccation rate in successful anhydrobiosis of Panagrolaimus detritophagus

We examined the effect of nutritional status and desiccation rate on the ability of Panagrolaimus detritophagus to undergo anhydrobiosis, as well as to survive high temperatures in the dried state. Both nutrition and drying rate were found to be important, with starvation and slow drying providing better success at anhydrobiosis. The upper temperature for survival of dried animals in laboratory studies was 80 degrees C. Starved worms recovered from drying more successfully when the starvation period was followed by a smooth, gradual dry period prior to undergoing desiccation. Thus, the ability of these worms to enter and leave anhydrobiosis is dependent on critical stress signals