Сравнительный анализ нелинейных резонансов механической системы с несимметричной кусочно-линейной характеристикой восстанавливающей силы

Представлены результаты численного сравнительного анализа супергармонических резонансов порядка 2/1...5/1 и субгармонического резонанса порядка 1/2 механической колебательной системы с одной степенью свободы с несимметричной кусочно-линейной характеристикой восстанавливающей силы при различных соотношениях жесткости системы на полуциклах и в условиях существенного изменения уровня демпфирования колебаний в системе.Представлено результати числового порівняльного аналізу супергармоніч- них резонансів порядку 2/1...5/1 і субгармонічного резонансу порядку 1/2 механічної коливної системи з одним ступенем вільності з несиметричною кусково-лінійною характеристикою відновлювальної сили при різних співвідношеннях жорсткості системи на півциклах і в умовах суттєвої зміни рівня демпфірування коливань у системі.We present results of the numerical comparative analysis of superharmonic resonances of 2/1-5/1 order and a sub-harmonic resonance of 1/2 order of mechanical vibratory systems with one degree of freedom with asymmetrical piecewise linear performance of recovering force for various system rigidity ratios in half-cycles and for conditions of significant variation of the level of vibration damping in the system

Аналіз провідних складових маркетингового потенціалу аграрного сектора економіки

Визначено та проаналізовано провідні складові маркетингового потенціалу аграрного сектора економіки: трудовий (кадровий), фінансовий потенціал; організаційне, управлінське та інформаційне забезпечення маркетингу; потенціал маркетингових підрозділів. Акцентовано увагу на відсутності маркетингових підрозділів у сільськогосподарських підприємствах, низькому рівні розвитку цього потенціалу в цілому. Наголошено на необхідності розробки заходів щодо підвищення ефективності господарювання підприємств аграрної галузі із застосуванням маркетингуCertainly and the leading constituents of marketing potential of agrarian sector of economy are analyzed. Attention is accented on absence of marketing subsections in agricultural enterprises low level of development of this potential on the whole. It will provide development of measures on the increase of efficienc y of menage enterprises of this industry

Continuous affect state annotation using a joystick-based user interface

Ongoing research at the DLR (German Aerospace Center) aims to employ affective computing techniques to ascertain the emotional states of users in motion simulators. In this work, a novel user feedback interface employing a joystick to acquire subjective evaluation of the affective experience is presented. This interface allows the subjects to continuously annotate their affect states, elicited in this scenario by watching video clips. Several physiological parameters (e.g. heart rate, electrodermal activity, respiration rate, etc.) were acquired during the viewing session. A statistical analysis is presented, which shows expected patterns in data that validate the design and methodology of the experiment and lay the groundwork for further experiments to be undertaken at the DLR

Stress, endogenous opioids and stereotypies in tethered pigs

Tether housing of female pigs in narrow, individual boxes represents a chronic stressor for the animals. Pigs that are housed tethered often develop behavioural disturbances, such as stereotypies, and changes in physiological regulation. The results of the studies described in the present thesis confirm and extend previous suggestions that there is an association between stereotypies and brain opioid activity. We found a negative correlation between the intensity of stereotypy performance and opioid receptor densities in the hippocampus and the hypothalamus of pigs which had been housed tethered for two months. This correlation seemed to disappear with increasing duration of tether housing, likely as a consequence of the gradual decrease in receptor density that occurred in pigs with low levels of stereotypies. This receptor decrease might reflect glucocorticoid-induced neuronal cell loss, since we also found a negative correlation between he salivary cortisol concentration and the number of neurons in the hippocampus in long-term tether housed pigs. These results accord with the idea that stereotypies represent a strategy to reduce adverse effects of chronic stress.The chronic stress of tether housing not only leads to the development of stereotypies, it can also induce changes in physiological responsivity to further stressful stimulation. The mechanisms underlying these changes likely include alterations in endogenous opioid systems. This is indicated by our finding that antagonism of endogenous opioid activity increased the heart rate response of pigs to a stressful challenge after long-term tether housing but not after loose housing. These results provide evidence indicating that long-term tether housing leads to an increased impact of endogenous opioid systems that attenuate physiological responses to additional acute stress.Taken together, the present thesis highlights changes in endogenous opioid activity that are induced by chronic stress and appear to prevent or reduce potentially harmful stress effects

Brain opioid receptor density reflects behavioral and heart rate responses in pigs

Results from our previous research indicate that long-term tether-housed pigs with high and low levels of stereotypies show differences in the density of endogenous opioid receptors in the hippocampus and hypothalamus. It was not clear whether differences in opioid receptor density were induced by the chronic stress of tether housing or stereotypy performance, or were already present before the animals were tethered. The latter possibility was tested in the present experiment. We used a group of 18 nonstereotyping pigs that had no experience with tether housing and investigated whether the animals differed in the density of endogenous opioid receptors in the brain and, if so, whether these differences were related to the animals' reactions to acute challenges. The pigs were subjected to two tests: an open field test and a tethering test. Behavioral reactions as well as heart rate responses were measured. Opioid receptor densities were determined postmortem in the hippocampus and hypothalamus using a membrane binding assay with [3H]naloxone as a ligand. Animals differed widely in their responses to the two tests. In support of our hypothesis, we found a relationship between behavioral and heart rate responses and densities of naloxone binding sites in the hippocampus and hypothalamus. The data suggest that endogenous opioid systems in the brain contribute to differences in stress responding between individual pigs

Brain opioid receptor density relates to stereotypies in chronically stressed pigs

Opioid receptor densities were measured in the hippocampus of chronically stressed (tethered) pigs to study the involvement of endogenous opioid systems in stereotypy performance. Three groups of animals were housed tethered for 2 (n = 12), 5.5 (n = 12) and 8-9 months (n = 8), respectively, and the intensity of stereotypy performance was determined. Opioid receptor densities were measured post mortem, using membrane binding assays with [ 3H]naloxone as a ligand. A negative correlation was found between the density of opioid receptors and the intensity of stereotypy performance in the animals that had been housed tethered for 2 months. This correlation seemed to disappear with increasing duration of tethered housing. The data further suggest that, associated with the duration of tethered housing, there was a gradual decrease in the density of opioid receptors in the left hippocampal lobe of the low-stereotyping animals, but not in the right lobe, nor in the left and right lobes of the high-stereotypers. This suggests that chronic stress leads to a (asymmetrically expressed) progressive loss of opioid receptors in the hippocampus, and that stereotypies exert a mitigating effect on stress-induced changes in opioid receptor densities, supporting the hypothesis that stereotypies help the animals cope with the adverse effects of chronic stress

Opioid activity in behavorial and heart rate responses of tethered pigs to acute stress

In a longitudinal experiment, effects of long-term tether housing on heart rate and behavioral responses to an acute stressor (a 15-min challenge with a nosesling) were investigated in pigs. The animals were challenged during loose housing and again after 10–11 weeks of tether housing. To detect possible changes in endogenous opioid systems modifying these responses, the pigs were pretreated with the opioid receptor antagonist naloxone (0.5 mg/kg body weight, iv). In response to the nosesling challenge, the animals showed pronounced resistance behavior and a sharp rise in heart rate. Following this initial phase of resistance, the heart rate dropped to prechallenge levels or below this line, and the pigs seemed to become sedated. Pretreatment with naloxone increased the heart rate response in animals that were long-term tether housed (n=12). No such effect was found in the control group (n=5) that was loose-housed during the entire experiment, indicating that the impact of endogenous opioid systems mitigating heart rate responses to acute stress had increased as a result of long-term tether housing. Changes in the effect of naloxone on the behavioral response were not found. Adaptive changes in opioid systems may prevent excessive physiological reactions to acute stress and, thus, may serve as a coping mechanism

Bedding-in and Rooming-in on the post-natal ward: breastfeeding initiation

Hospitals making a commitment to the UNICEF UK Baby Friendly Initiative adopt a number of practices to help increase breastfeeding initiation rates. Allowing mothers and their infants uninterrupted skin to skin contact for at least the first 30 minutes following delivery and keeping mothers and babies close are two of the practices that have been shown to encourage breastfeeding initiation. Bedding-in (bed-sharing on the postnatal ward) is an obvious extension to skin-to-skin contact and a way of ensuring that mothers and their infants stay close. Bedding-in also has a number of other benefits in that it can facilitate bonding and assists in post partum rest for mothers. This randomised control trial investigated the effects of bedding-in compared to rooming-in on breastfeeding initiation, mother-infant contact, maternal responsiveness, midwifery assistance and infant safety required on the first post-natal night. In addition, a relatively new infant sleep condition (clip on crib) was assessed to determine whether infants and their mothers allocated to this condition behaved more like the bedding-in group or the rooming-in group. This presentation will concentrate on breastfeeding initiation in the three groups only. Mothers were recruited via breast-feeding workshops held within the Royal Victoria Infirmary, Newcastle-Upon-Tyne, England, when they were approximately 37 weeks gestation. Following vaginal delivery (without the use of intramuscular opiate analgesics) the behaviors and interaction of the mothers and their babies were recorded on the post-natal ward using infra-red video equipment. Tapes were coded using The Observer® (Noldus Information Technology bv, The Netherlands) according to a taxonomy used by the Parent-Infant Sleep Lab team at the University of Durham. We found that mothers who bed-in were more responsive to their infants’ feeding cues, breastfed more frequently and breastfed for longer durations when initiating breastfeeding on the first postnatal night

Bedding-in and rooming-in on the post-natal ward : breastfeeding initiation.

Hospitals making a commitment to the UNICEF UK Baby Friendly Initiative adopt a number of practices to help increase breastfeeding initiation rates. Allowing mothers and their infants uninterrupted skin to skin contact for at least the first 30 minutes following delivery and keeping mothers and babies close are two of the practices that have been shown to encourage breastfeeding initiation. Bedding-in (bed-sharing on the postnatal ward) is an obvious extension to skin-to-skin contact and a way of ensuring that mothers and their infants stay close. Bedding-in also has a number of other benefits in that it can facilitate bonding and assists in post partum rest for mothers. This randomised control trial investigated the effects of bedding-in compared to rooming-in on breastfeeding initiation, mother-infant contact, maternal responsiveness, midwifery assistance and infant safety required on the first post-natal night. In addition, a relatively new infant sleep condition (clip on crib) was assessed to determine whether infants and their mothers allocated to this condition behaved more like the bedding-in group or the rooming-in group. This presentation will concentrate on breastfeeding initiation in the three groups only. Mothers were recruited via breast-feeding workshops held within the Royal Victoria Infirmary, Newcastle-Upon-Tyne, England, when they were approximately 37 weeks gestation. Following vaginal delivery (without the use of intramuscular opiate analgesics) the behaviors and interaction of the mothers and their babies were recorded on the post-natal ward using infra-red video equipment. Tapes were coded using The Observer® (Noldus Information Technology bv, The Netherlands) according to a taxonomy used by the Parent-Infant Sleep Lab team at the University of Durham. We found that mothers who bed-in were more responsive to their infants’ feeding cues, breastfed more frequently and breastfed for longer durations when initiating breastfeeding on the first postnatal night