A decrease in quality and quantity of sleep has a negative impact on efficiency during wakefulness, which shows particularly in case of people who interact with technological systems, for example system operators, vehicle drivers, etc. Day sleep can positively influence the following vigilance but in the time immediately after the sleep, the psychomotor performance is influenced by sleep inertia whose intensity depends on time and length of sleep.
The aim of the study was to compare day psychomotor performances of people suffering from sleep disorders and a control group of healthy people, and to test the hypothesis that a short, 15 minute long sleep causes more important sleep inertia at 3 p.m. than at 1 p.m.
Sleepiness was objectively evaluated on a group of 35 tested probands, consisting of 29 patients (13 women and 16 men) with given excessive daytime sleepiness accompanying sleep disorder, and of a control group of 6 healthy subjects, with help of Multiple Sleep Latency Test (MSLT) and subjectively with help of Alertness Visual Analogue Scale (VAS). Psychomotor performance was examined by Psychomotor Vigilance Task (PVT).
We found out an unimportant difference in the intensity of sleep inertia after a sleep at 1 p.m. and 3 p.m. We proved significant prolongation of a reaction time and an increase in number of lapses on the group with pathologically shortened sleep latency in MSLT compared to the group with the normal sleep latency. Our work also shows the difference between the subjective and objective evaluation of sleepiness of subjects. Our results show that the prolonged reaction time and increase in number of lapses of the patient group are significant in all PVT examinations compared to the control group. Further, it is obvious that the PVT test is a more sensitive method for judging psychomotor performance and indirectly for judging sleepiness than the MSLT.
These facts seem to be important especially from the two following reasons:
- They can be a help for recommendation of improved regime for driver relaxation.
- They can help in search for deeper understanding of mechanisms of attention decreases.
Viticulture is one of the most intensively managed agricultural ecosystems in Europe. Therefore, the conservation problems of vineyards and the ecological benefits of increasing the amount of fallow land are addressed using butterflies as a model group. We established 43 transects, each 100 m long, in a vineyard region in the vicinity of Trier (Rhineland-Palatinate, Germany) and recorded the butterflies observed along these transects on 20 occasions from late May to early August 2003. Transects crossed vineyards, fallow land and transitional areas of land. 4041 individuals of 34 species showed the typical pattern of relative abundance with few common and many relatively rare species. Fallow land had more individuals and species and a higher Shannon species diversity index than vineyards. Community evenness and average butterfly dispersal ability were highest in the vineyards. Principal Factor Analyses and UPGMA cluster analysis distinguished between fallow land and vineyards. The difference between early meadow and late forest fallow land areas was not strong, but the former tended to have a higher diversity than the latter. Vineyards thus might act as a sink for butterflies. Therefore, a clear separation between vineyards and fallow land is best for nature conservation. As young fallow land tends to have a higher diversity than older fallow land in this study, it is likely that the conservation value of vineyards for butterflies could be increased by active management of fallow land areas.
More than half of the insects collected on snow in Central Poland were flies (Diptera). Altogether 83 species of Diptera from 27 families were identified, of which 9 families were recorded for the first time. Two thirds of the Diptera belonged to the Mycetophilidae and Trichoceridae, which were also very species-rich. Other families with many species were the Heleomyzidae, Sphaeroceridae and Phoridae.
The peak activity was in the first part of December. Flies were most active on snow when the humidity ranged from 80 to 100%, temperatures between -1 to 5°C and the snow was from 20 to 40 cm deep. The occurrence of Trichoceridae was strictly associated with high humidities, in contrast to Drosophilidae and Heleomyzidae, which were most active at lower humidities. The activity of the flies of the most frequently recorded families was displaced towards either lower (Heleomyzidae and Limoniidae) or higher temperatures (Trichoceridae, Mycetophilidae). In contrast to other families, the supranivean activity of Phoridae was strictly associated with thin snow cover.
I hypothesized that sibling cannibalism is one of maternal investment in that a female controls sibling cannibalism. To test the hypothesis, I conducted a laboratory experiment and field observations to investigate sibling cannibalism in relation to cluster size and cluster site in the ladybird beetle, Harmonia axyridis Pallas. In the laboratory experiment, cluster size significantly affected the number of cannibalized eggs per cluster (R2 = 0.516), while cluster size was significantly affected by the oviposition interval. Furthermore, there was a marginally significant positive relationship between cluster size and the percentage of sibling cannibalism per cluster. In the field, cluster size and the direct distance from a cluster site to an aphid colony (an indicator of intensity of non-sibling cannibalism) significantly affected the number of cannibalized eggs per cluster (R2 = 0.472). Furthermore, there was a significant positive relationship between the direct distance from a cluster to the nearest aphid colony and cluster size. However, there was not a significant relationship between the distance and the percentage of sibling cannibalism. These results may be caused by the weakness of the female's power to control sibling cannibalism. Thus, a female H. axyridis controls cluster size through the intensity of non-sibling cannibalism, which may be one of oviposition strategies in this species.
The resuits of the Hard X-Ray Imaging Spectrometer on the Solar Maximum Mission are reviewed. Particular emphasis ís given to those results which address phenomena which cannot easily be studied by the other instruments. Among the important discoveries are the following: it has been established that during the onset of the impulsive phase the hard X-rays are emitted from the footpoints of the flare loop, cospatial with the Hα kernels; very large, coronal loops, often containing plasma with temperatures up to 10^K,
are probably quasi-permanent features of the solar atmosphere; there are often soft X-ray precursors from points separated by ^ 10^ km which signal the onset of coronal mass ejections; following the onset of the impulsive phase hot plasma is observed to rise into the corona, sometimes inhibiting further energy input to the chromosphere; surges and prominences may be emitting weakly in soft X-rays during certain phases of their evolution; rapidly-varying
(^ 10‘s) soft X-ray spikes are occasionally seen, with unpredictable corresponding hard X-rays; and there has been a tentative identification of photospheric albedo, backscattered from the hard X-ray emitting plasma as it rises into the low corona.
Several studies have investigated the association between infection with Toxoplasma gondii (Nicolle et Manceaux, 1908), pregnancy and fertility, but the results of studies focused on the fertility are rather ambiguous. Here we report results of four new cross-sectional studies. The studies were performed in the General University Hospital, Prague (study A with n = 1 165, and study C with n = 317), in private clinics of the Centre of Reproductive Medicine, Prague (study B with n = 1 016), and in a population of Czech and Slovak volunteers from the Facebook page 'Guinea Pigs' willing to participate in various basic science studies (study D with n = 524). In studies A and B, the clinical records were used to assess the fertility problems, whereas in studies C and D, the women were asked to rate their fertility problems using a six-point scale. Pregnant T. gondii-infected women were older than T. gondii-free women (study A: 33.1 vs 31.2, P < 0.001; study B: 30.6 vs 29.6, P = 0.012) and more often used assisted reproductive technology to conceive (study A: 17.2% vs 12.4%, P = 0.041; study B: 13.4% vs 9.2%, P = 0.317). Pregnant T. gondii-infected primiparous women were older than T. gondii-free primiparas (study A: 31.1 vs 29.5, P < 0.001; study B: 29.7 vs 28.9, P = 0.064) and more often used assisted reproductive technology to conceive (study A: 24.7% vs 14.4%, P = 0.010; study B: 15.9% vs 15.5%, P = 0.888). T. gondii-infected women reported to take a longer time to conceive than T. gondii-free women (P = 0.015). They also claimed to have more fertility problems than T. gondii-free women (P < 0.0001). Our results suggest that 'asymptomatic' latent toxoplasmosis could be a more serious source of fertility problems and health-associated burden than more severe but far rarer congenital toxoplasmosis., Šárka Kaňková, Jaroslav Flegr, Pavel Calda., and Obsahuje bibliografii