Investigations of a simulated geomagnetic field experienced by the International Space Station on attentional performance.

We have previously reported that the exposure to an abnormal magnetic field simulating the one encountered by the International Space Station (ISS) orbiting around the Earth may enhance autonomic response to emotional stimuli. Here we report the results of the second part of that study which tested whether this field also affects cognitive functions. Twenty-four volunteers participated in the study, 12 exposed to the natural geomagnetic field and 12 to the magnetic field encountered by ISS. The test protocol consisted of a set of eight tests chosen from a computerized test battery for the assessment of attentional performance. The duration of exposure was 90 min. No effect of exposure to ISS magnetic field was observed on attentional performance.

Simulation of the geomagnetic field experienced by the International Space Station in its revolution around the Earth: effects on psychophysiological responses to affective picture viewing.

There is evidence suggesting that exposure to an abnormal magnetic environment may produce psychophysiological effects related to abnormalities in responses to stress. This may be of relevance for space medicine where astronauts are exposed to a magnetic field different from that exerted by the Earth. Aim of this study was to assess how the exposure of the head to a magnetic field simulating the one encountered by the International Space Station (ISS) during a single orbit (90 min) around the Earth affects the cardiovascular and psychophysiological parameters. Twenty-four human volunteers were studied double blindly in random order under sham and magnetic exposure. During exposure, the persons were shown a set of pictures of different emotional content while subjective self-rating, skin conductance (SC), blood pressure (BP), and heart rate (HR) were measured. In addition, BP, HR, and tooth pain threshold were assessed before and after exposure. While subjects were under magnetic exposure, skin conductance was strongly differentiated (F(2,36)=22.927; p=0.0001), being high during emotionally involving (positive and negative) pictures and low during neutral pictures. Conversely, when subjects were under sham exposure, no significant differences were observed. There was, however, a trend for higher heart rate during picture viewing under magnetic exposure as compared to sham exposure. No effects were found for the other variables. These results suggest that an abnormal magnetic field that simulates the one encountered by ISS orbiting around the Earth may enhance autonomic response to emotional stimuli.

Artificial life and speciation, a case study: heterochromatin and speciation in the Microtus savii Group (Rodentia-Arvicolinae).

Artificial life is a tool which is used for simulation of peculiar cases of evolutionary events. The main characteristic of artificial life is that with this technique it is possible to simulate for a high number of generations the evolution of a population of individuals. Each individual is characterised by a small number of parameters, but each individual has its own evolutive story. So far it is possible to simulate the evolution of a population of some thousands specimens, for a high number of generations. The realistic aspect of the simulation is that each specimen is taken individually. In our opinion this instrument is very useful to simulate the evolution of the hybrids barrier during speciation. For this reason it is applied to a peculiar case of speciation, that of the Savi pine vole (Microtus savii) whose experimental data were recently investigated.

Towards a theory of meaning in biology: a proposal for an operative definition.

Information is a concept developed inside the context of computational and computer sciences. Entropy is a concept developed inside physics context. The best concept in biology is that of "meaning" which is quite impossible to be measured as stated by some examples which are reported. A suggestion to develop a discussion in order to obtain an integration of these concepts inside the general problems of evolutionary biology is here reported to the attention of researchers.

Sleep disorders and daytime sleepiness in state police shiftworkers.

Police, who work shifts, participate in both risky and delicate tasks. The authors investigated sleep habits, prevalence of sleep disorders, sleepiness on the job, and hypnotic drug intake (Benzodiazepines, Zaleplon, Zolpidem, or Zoplicone) in a population of Italian state police officers. This study was conducted with self-administered questionnaires. The investigation focused on the difference between 540 non-shiftworkers (413 males, 127 females) and 575 shiftworkers (483 males, 92 females). All individuals were between 20 yr and 39 yr of age. In shiftworkers, there was a higher prevalence of difficulty in initiating sleep; in addition, these individuals had a sleep latency that exceeded 20 min, and they experienced early awakenings. No significant differences in daytime sleepiness and drug intake existed between the 2 groups. Self-evaluation of the number of hours that individuals slept each night and during a 24-hr period revealed that shiftworkers required more sleep. The results indicated that shiftworkers experienced a lower quality of sleep than non-shiftworkers, but the former did not report increased daytime sleepiness or increased hypnotic drug intake (i.e., Benzodiazepines, Zaleplon, Zolpidem, or Zoplicone). Shiftworkers seemed to compensate for the poor quality of their sleep by sleeping for a greater number of hours during 24-hr periods than the non-shiftworkers. Perhaps the aforementioned compensation resulted from a prolonged recovery from shiftwork effects.

Geophysiological modeling: new ideas on modeling the evolution of ecosystems.

Living organisms evolve within ecological associations (from ecosystems to the biosphere) that are constituted by a biological component and a physico-chemical component. It is generally supposed that interactions such as competition and predation between the biological components of ecosystems are the main cause for the observed organization of ecosystems. We believe that in the search for a more comprehensive theory of evolution a much greater attention should be paid to the ways in which living organisms interact with the physico-chemical environment. To test our ideas, we develop a mathematical model to study the evolution of ecosystems, and we apply it to the study of hydrothermal vents. The model proposed is still a qualitative model. It tries to study, in a first approximation, the behaviours of the biological and chemical components. In the following we hope to develop and to improve it so to give a more realistic model.