This study examined the effects of different types on anthropogenic disturbance on behaviours of grey herons Ardea cinerea, and great egrets Ardea alba, that gather in an Important Bird Area near Belgrade (Serbia), during their autumn migration, with the goal of assessing how diverse human-caused stimuli affect the behaviours of foraging and resting birds. I obtained behavioural data through scan sampling, with six categories of behaviour distinguished: vigilant, flying, feeding, comfort, inactive and other. In total, I collected 5,065 observations of individual birds: 1,293 for grey herons and 3,772 for great egrets. Significantly more birds were vigilant or in flight when they were disturbed by construction vehicles, military jets, and rural free-ranging dogs, whereas no statistical significance was associated with shooting and passing cars. Using a linear mixed model, it was shown that a greater proportion of birds was vigilant during disturbance than following disturbance or in the absence of disturbance, whereas air temperature and wind speed were not statistically significant. This study demonstrates that anthropogenic disturbance can alter the behaviour of the study species, which could aid future management and conservation planning.
Decrease of attention and an eventual microsleep of an artificial system operator is very dangerous and its early detection can prevent great losses. This chapter deals with a classification of states of vigilance based on analysis of an electroencefalographic activity of the brain. Preprocessing of data is done by the discrete Fourier transform. For the recognition radial basis functions (RBF), learning vector quantization (LVQ), multi-layer perceptron networks, k-nearest neighbor and a method based on Bayesian theory are used. Coefficients of bayes classifier are found using the maximum likelihood estimation. The experiments deal with analysis of human vigilance while their eyes are open. Then the reaction on visual stimuli is investigated. For this experiment 10 volunteers were repeatedly measured. The chapter shows that it is possible to classify vigilance in such conditions.
EEG activities with open eyes in a quiet state (OA), during pseudo-Raven's test (PRA), in a hypnagogic state (HYP) and REM sleep (REM) are marked by similar, nearly flat curves. Further we observed states with eyes closed (OC), with hyperventilation (HV), with calculation (CAL) and in NONREM 1 sleep (NR 1). During OA, the EEG spectrum contains some delta and but rudimental alpha activity while during PRA and in HY there is an increase in delta-theta and a significant decrease in alpha activities. Hence, not even Fast Fourier Transformation (FFT) can differentiate between the states with fkat curves. This made us introduce another EEG curve analysis for coherence function (CF). We investigated 24 healthy volunteers aged 22 -- 55 years, 19 men and 5 women, in the above mentioned eight states with simultaneous EEG recording.
Vigilance was controlled by means of acoustic stimulation, reactivity was expressed in reaction time (ReT), i.e. latency of response in milliseconds (ms). Imitation Raven's test (pseudo-Raven' = PRA) was used for psychic testing. Recorded in the afternoon hours after partial sleep deprivation, the EEG curve was described optically using FFT and CF as well. FFT results have already been mentioned above. CF showed lower values during OA with up to 400 ms of ReT, a diffuse increase during HYP with ReT of 800 - 1200 ms, and a multifocal rise of delta activity in the EEG curve during PRA.
Consequently, EEG analysis can help differentiate between the above eight states, otherwise barely distinguishable with the naked eye especially in cases with flat EEG curves. Using similar analyses, it is possible to discriminate all stages of NONREM and REM sleep without polysomnography.
Transportation of people and goods represents a still more significant
component of the human culture. Its influence is extremely high today and will increase greatly in the future.
Almost all the contemporary transportation systems are based on the necessity of interaction between the transportation tool (vehicle, plane, ship), the transport control system and the human subject. Though a large effort is put into the development of automatic transport systems, none of the present attempts is fully automatic, in all of them the human subject plays a non-neglectable role with considerably high impact on the reliability and safety of the transportation function. Among such functions the driving and control activity dominates.
The drivers, pilots, captains and transportation systems dispatchers and controllers are usually exposed to considerably long and exhausting Services, which could last up to 8 and even more hours.
It is generally known that the human subject is not able to retain in the state of vigilance without brakes and relaxation. Usually, its ability to concentrate his/her attention to some activity (like driving of systém control) decreases considerably soon, mainly after 45 or 60 niinutes only.
The decrease of human subject attention in the course of his/her activity is not monotone of course, it can involve several periods of temporary increases and decreases. However, without exception, if the exposition is long enough, the subject attention finally falls under the limit of acceptability for safe and reliable activity of the particular type. The subject activity becomes dangerous for him/her, his/her environment and for the driven vehicle, plane, ship or the controlled transportation system too. Finally, the subject falls in the stage of the so-called micro-sleep, in which he/she is not able to produce the particular driving or control activity at all.
A considerably large effort was given to the analysis of negative impacts of this factor. Unfortunately, the used methodology for such analyses differs up to now in many countries, so that the results are not quite comparable. However, one can estimate that between 15 and 40% of all the accidents on the roads are caused by the non-satisfactory level of the human subject attention. If we take into account that the average economic loss of one mortal road accident is estimated to more than 1 million Euro and if the density of such accidents is taken into account as well, we come to a tremendous figure, which has to be enlarged more by the estimation of losses of non-mortal accidents.
In rats, the basic licking rhythm is generated by the central pattern generator located in the brainstem. Nevertheless, the licking frequency can be regulated between abou 7.5 and 4 Hz by changing the drinking conditions. If these conditions are kept constant, the licking frequency can be influenced only to a minor degree by factors such as deprivation level, type of solution, and phase of the session. The aim of our study was to compare the licking frequency of rats at different levels of vigilance. We investigated spontaneous licking of rats by an electrical lick sensor; parallel behavior monitoring was also performed. Animals kept in a stable environment and showing a lower level of vigilance licked at a rate of 5.96 Hz, fully vigilant rats licked significantly more rapidly at a frequency 6.57 Hz. The fastest rate of licking (6.49 Hz and 6.82 Hz, respectively) was encountered in alert rats under a mild stress caused by the presence of a second animal in the experimental box. The vigilance level is thus another factor affecting the licking rate of rats that should be taken into account in behavioral licking experiments., O. Vajnerová, E. Bielavská, P. Jiruška, G. Brožek., and Obsahuje bibliografii
In modern society, many people keep working hours different from the standard (9 hours, 5 days a week during conventional time of the day), a regimen leading to sleep deprivation and/or circadian desynchronization, and, consequently, to sleepiness, fatigue, impaired efficiency and ultimately to psychic and somatic complaints. Fortunately, sleepiness-related health and occupational hazards can be kept under control using scientifically tested precautions designed to help maintain wakefulness. Suitable work and rest scheduling and observance of the principles of sleep hygiene are of major importance there. In situations which interfere with sleep, it is possible to use hypnotics or behavioral techniques and melatonin for circadian regimen optimization. In situations when sleep loss is temporarily inevitable, options to be taken into account include work shift shortening, breaks for rest, naps of short duration or administration of vigilance enhancing drugs. In the future, risks associated with sleepiness could be mitigated by means of currently developed technologies for real-time detection of sleepiness.
EEG activities with open eyes in a quiet state (OA), during the pseudo-Raven's test (PRA), in hypnagogic state (HYP) and in the course of REM sleep (REM) are characteristic by nearly flat curves. We observed the states with eyes closed (OC), with hyperventilation (HV), during mental activity of calculation (CAL) and in NONREM 1 sleep (NR 1). 24 tested persons (probands) were investigated. We have found 8 typical states of EEG signals, which all have relation to attention and mental activity. Consequently, the EEG analysis can help in the differentiation between the above eight states. Using similar analyses, it is possible to discriminate all stages of NONREM and REM sleep without polysomnography.