Demography in eusocial Hymenoptera

In my doctoral thesis I investigated the evolution of demographic traits within eusocial Hymenoptera. In the social bees, wasps and ants, eusociality has a unique effect on life span evolution as female larvae with the same genetic background can develop through phenotypic plasticity to a queen or a worker with vastly diverging life-history traits. Ant queens belong to the longest-lived insect species, while workers in most species live only a fraction of the queen’s life span. The average colony size of a species is positively correlated with social complexity, division of labor and diverging morphological female phenotypes all of which also affect life span. Therefore the demographic traits of interest in this thesis were life span and colony size. To understand the evolution of worker life span I applied a trade-off model that includes both hierarchical levels important in eusocial systems, namely the colony- and the individual-level. I showed that the evolution of worker life span may be an adaptive trait on the colony level to optimize resource allocation and therefore fitness in response to different levels of extrinsic mortality. A shorter worker life span as a result of reduced resource investments under high levels of extrinsic mortality increases colony fitness. In a further study I showed that Lasius niger colonies produce different aging phenotypes throughout colony development. Smaller colonies which apply a different foraging strategy than larger colonies produced smaller workers, which in turn have a longer life span as compared to larger workers produced in larger colonies. With the switch to cooperative foraging in growing colonies individual workers become less important for the colony caused by their increasing redundancy. Alternatively a trade of between growth and life span may lead to the results found in this study. A further comparative analysis to study the effect of colony size on life span showed a correlation between queen and worker life span when colony size is taken into account. While neither worker nor queen life span was associated with colony size, the differences between queen and worker life span increase with larger average colony sizes across all eusocial Hymenoptera. As colony size affects both queen and worker life span, I aimed to understand which factors lead to the small colony sizes displayed by some ant species. I therefore analyzed per-capita productivity at different colony sizes of eight cavity dwelling ant species. Most colonies of the study species grew larger than optimal productivity predicted. Larger colony size was shown to increase colony homeostasis, the predictability of future productivity and in turn the survival probability of the colony. I also showed that species that deploy an individual foraging mode may circumvent the density dependent decline in foraging success by splitting the colony to several nest sites.

Fitness App per Win/Android - FitMaster

L’obiettivo di questa tesi è quello di progettare un sistema gestionale che risponda alle esigenze organizzative delle palestre. In particolar modo verrà implementato un software per piattaforma Windows dedicato ai personal trainer. Questa applicazione dovrà essere in grado di registrare e gestire i clienti del centro sportivo, e permettere la creazione degli allenamenti a loro dedicati (con l’utilizzo quindi di schede, esercizi, serie, ripetizioni, ...). Tutti i dati andranno memorizzati su un server SQL centralizzato, accessibile anche da Internet. Successivamente questi allenamenti potranno esser scaricati e visualizzati dai clienti tramite i propri Smartphone Android.

Physicians' knowledge and continuing medical education regarding fitness to drive: a questionnaire-based survey in Southeast Switzerland

Valid information for physicians in Switzerland concerning knowledge and continuing education in traffic medicine is not available. Also, their attitude to the legally prescribed periodic driving fitness examinations is unclear. In order to gain more information about these topics, 635 resident physicians in Southeast Switzerland were sent a questionnaire (response rate 52%). In a self-estimation, 79% of the queried physicians claimed to know the minimal medical requirements for drivers which are important in their specialty. Statistically significant differences existed between the specialties, whereby general practitioners most frequently claimed to know the minimal medical requirements (90%). It appears that the minimal medical requirements for drivers are well known to the queried physicians. Fifty-two percent of the physicians favored an expansion of continuing education in traffic medicine. Such an expansion was desired to a lesser extent by physicians without knowledge of the minimal requirements (p < 0.001). A clear majority of the medical professionals adjudged the legally prescribed periodic driving fitness examinations as being an expedient means to identify unfit drivers. A national standardized form for reporting potentially unfit drivers to the licensing authorities was supported by 68% of the responding physicians. Such a form could simplify and standardize the reports to the licensing authorities.

[Consensus recommendations for the assessment of fitness to drive in cognitively impaired patients]

Memory Clinics provide evidence based diagnosis and treatment of dementia. Whenever a diagnosis of dementia is made, it is important to inform the patients about the possible impact of dementia on driving. Patients and their next of kin require competent advice whenever this difficult question is addressed and the mobility desire and the risks related to driving need to be carefully weight up. The time of diagnosis does not necessarily equate to the time when a person with dementia becomes an unsafe driver. The cause and severity of dementia, comorbidities and the current medication need to be carefully taken into account for this decision. On behalf of the association of the Swiss Memory Clinics, a group of experts has developed recommendations to assess fitness to drive in cognitively impaired older adults.

Intramyocellular lipid variations in active older men: relationship with aerobic fitness

Intramyocellular lipid (IMCL) variations in older men are poorly explored. In young adults, IMCL can be influenced by both diet and exercise interventions; this flexibility is related to aerobic fitness. We evaluated in active older adults the influence of maximal aerobic capacity on short-term diet and exercise-induced variations in IMCL stores.

Effects of Aerobic Fitness and Adiposity on Coagulation Biomarkers in Men vs. Women with Elevated Blood Pressure

A hypercoagulable state is a potential mechanism linking elevated blood pressure (BP), adiposity and a sedentary lifestyle to development of coronary heart disease (CHD). We examined relationships among aerobic fitness and adiposity in 76 sedentary subjects with elevated BP. Blood levels of plasminogen activator inhibitor-1 (PAI-1), D-dimer, von Willebrand factor (vWF) and thrombomodulin were assessed as biomarkers of coagulation. In individuals with elevated BP, percent body fat and fitness were associated with biomarkers indicative of a hypercoagulable state, even after demographic and metabolic factors were considered. D-dimer was positively associated with percent body fat (beta=0.37, p=0.003). PAI-1 was higher in men than in women (beta=-0.31, p=0.015) and associated with lower VO2peak (beta=-0.35, p=0.024). Thrombomodulin was positively associated with VO2peak (beta=0.56, p< 0.01). vWF was not significantly associated with fitness or adiposity. Our results emphasise that both percent body fat and physical fitness are important in the maintenance of haemostatic balance.

Biologically relevant sex differences for fitness-related parameters in active octogenarians

The number of elderly people is growing in western populations, but only few maximal performance data exist for people >75 years, in particular for European octogenarians. This study was performed to characterize maximal performance of 55 independently living subjects (32 women, 81.1 +/- 3.4 years; 23 men, 81.7 +/- 2.9 years) with a focus on sex differences. Maximal performance was determined in a ramp test to exhaustion on a bicycle ergometer with ergospirometry, electrocardiogram and blood lactate measurements. Maximal isometric extension strength of the legs (MEL) was measured on a force platform in a seated position. Body composition was quantified by X-ray absorptiometry. In >25% of the subjects, serious cardiac abnormalities were detected during the ramp test with men more frequently being affected than women. Maximal oxygen consumption and power output were 18.2 +/- 3.2 versus 25.9 +/- 5.9 ml min(-1) kg(-1) and 66 +/- 12 versus 138 +/- 40 W for women versus men, with a significant sex difference for both parameters. Men outperformed women for MEL with 19.0 +/- 3.8 versus 13.6 +/- 3.3 N kg(-1). Concomitantly, we found a higher proportion of whole body fat in women (32.1 +/- 6.2%) compared to men (20.5 +/- 4.4%). Our study extends previously available maximal performance data for endurance and strength to independently living European octogenarians. As all sex-related differences were still apparent after normalization to lean body mass, it is concluded that it is essential to differentiate between female and male subjects when considering maximal performance parameters in the oldest segment of our population.