Effects of Time of Day and Sleep Deprivation on Motorcycle-Driving Performance

The aim of this study was to investigate whether motorcycle handling capabilities – measured by means of the efficiency of emergency manoeuvres – were dependent on prior sleep deprivation and time of day. Twelve male participants voluntarily took part in four test sessions, starting at 6 a.m., 10 a.m., 2 p.m., and 6 p.m., following a night either with or without sleep. Each test session comprised temperature and sleepiness measurements, before three different types of motorcycling tests were initiated: (1) stability in straight ahead riding at low speed (in “slow motion” mode and in “brakes and clutch” mode), (2) emergency braking and (3) crash avoidance tasks performed at 20 kph and 40 kph. The results indicate that motorcycle control at low speed depends on time of day, with an improvement in performance throughout the day. Emergency braking performance is affected at both speeds by time of day, with poorer performance (longer total stopping distance, reaction time and braking distance) in the morning, and also by sleep deprivation, from measurements obtained at 40 kph (incorrect initial speed). Except for a tendency observed after the sleepless night to deviate from the initial speed, it seems that crash avoidance capabilities are quite unaffected by the two disturbance factors. Consequently, some motorcycle handling capabilities (stability at low speed and emergency braking) change in the same way as the diurnal fluctuation observed in body temperature and sleepiness, whereas for others (crash avoidance) the participants were able to maintain their initial performance level despite the high levels of sleepiness recorded after a sleepless night. Motorcycle riders have to be aware that their handling capabilities are limited in the early morning and/or after sleep deprivation. Both these situations can increase the risk of falls and of being involved in a road accident

Sleep-amount differentially affects fear-processing neural circuitry in pediatric anxiety: A preliminary fMRI investigation

Insufficient sleep, as well as the incidence of anxiety disorders, both peak during adolescence. While both conditions present perturbations in fear-processing-related neurocircuitry, it is unknown whether these neurofunctional alterations directly link anxiety and compromised sleep in adolescents. Fourteen anxious adolescents (AAs) and 19 healthy adolescents (HAs) were compared on a measure of sleep amount and neural responses to negatively valenced faces during fMRI. Group differences in neural response to negative faces emerged in the dorsal anterior cingulate cortex (dACC) and the hippocampus. In both regions, correlation of sleep amount with BOLD activation was positive in AAs, but negative in HAs. Follow-up psychophysiological interaction (PPI) analyses indicated positive connectivity between dACC and dorsomedial prefrontal cortex, and between hippocampus and insula. This connectivity was correlated negatively with sleep amount in AAs, but positively in HAs. In conclusion, the presence of clinical anxiety modulated the effects of sleep-amount on neural reactivity to negative faces differently among this group of adolescents, which may contribute to different clinical significance and outcomes of sleep disturbances in healthy adolescents and patients with anxiety disorders

The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts

The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts. June 4-7, 2019, Szczyrk, Polan

Dynamic site index curves for Scots pine (Pinus sylvestris L.) in southern Poland

The aim of the study was to develop a site index model for Scots pine stands in southern Poland describing changes in height growth of stand's upper storey over time. The research material contained the height growth data obtained from an analysis of 189 tree stems. The collected material was used to develop the parameters of six dynamic growth equations which allowed to determine site productivity and predict changes in height growth of stands with age. Statistical criteria for assessing the accuracy of mapping empirical data and biological reasonableness were the basis of selection of the equation that best fits changes in height growth of the examined pine stands with age. The developed model can be used to predict the growth rate and determine the site index for Scots pine stands in southern Poland

Dynamic site index curves for Scots pine stands in Niepolomice Primeval Forest

The aim of the research was to evaluate, under the conditions of the Niepołomice Primeval Forest, the usefulness of site index models applied in forest practice in Poland and to develop a local system of site index curves for Scots pine. The research materials included measurement results for the trees growing on 74 circular, 0.05 ha sample plots. On the basis of the completed analyses, the age−related change in stand heights in the Niepołomice Primeval Forest is different than the height growth described by means of the site index models used in forest practice in Poland. As a result of several−stage analyses, a dynamic system of site index curves was developed for the Niepołomice Primeval Forest allowing calculation of the site index, as well as forecast of the height of stands at any age

Study on analytical procedure of plutonium separation from air aerosols collected on Petrianov filter

A standard procedure for the determination of plutonium in soil was modified and applied for the assay of this element in dust and aerosols collected from ground-level air on a Petrianov filter, in an ASS-500 air monitoring station. The modification consists in replacing a dry ashing mineralization step by direct acid leaching. The problem of polonium interference with plutonium determination was also discussed and the concentration of polonium in air was estimated