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Adaptive Behaviour (adaptive + behaviour)
Terms modified by Adaptive Behaviour Selected AbstractsSplit agent-based routing in interconnected networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 4 2004Constandinos X. Mavromoustakis Abstract Adaptive behaviour of swarm-based agents (BT Technol. J. 1994; 12:104,113; AAMAS Conference '02, Melbourne, Australia, Month 1,2, 2002; Softcomput. J. 2001; 5(4):313,317.) is being studied in this paper with respect to network throughput for a certain amount of data traffic. Algorithmically complex problems like routing data packets in a network need to be faced with a dynamically adaptive approach such as agent-based scheme. Particularly in interconnected networks where multiple networks are participating in order to figure a large-scale network with different QoS levels and heterogeneity in the service of delay sensitive packets, routing algorithm must adopt in frequent network changes to anticipate such situations. Split agent-based routing technique (SART) is a variant of swarm-based routing (Adapt. Behav. 1997; 5:169,207; Proceedings of 2003 International Symposium on Performance Evaluation of Computer and Telecommunication Systems,SPECTS, Montreal, Canada, July 20,24, 2003; 240,247.) where agents are split after their departure to the next node on a hop-by-hop basis. Packets that are delay sensitive are marked as prioritized which agents recognize-as being a part of a packet- and try to influence the two-way routing tables. Thorough examination is made, for the performance of the proposed algorithm in the network and the QoS offered, taking into account a number of metrics. It is shown that the split agent routing scheme applied to interconnected networks offers a decentralized control in the network and an efficient way to increase overall performance and packet control reducing at the same time the packet loss concept. Copyright İ 2004 John Wiley & Sons, Ltd. [source] Disturbance and habitat use: is edge more important than area?OIKOS, Issue 1 2006Alissa E. Moenting In their efforts to maximize fitness while reducing the probability of dying, animals must decide which patches to forage in, when to forage, and how long to forage in each patch. Each decision will be modified by habitat and habitat disturbance. We evaluate the effects of habitat disturbance on foraging behaviour by imagining an initially homogeneous environment that is altered to create patches of different sizes. Disturbance increases predation risk, or otherwise alters patch profitability. Foragers can respond by changing their pattern of foraging, or by reducing their activity. We develop predictions for each scenario. We then test the predictions with data on the abundance and foraging activity of meadow voles (Microtus pennsylvanicus) in and around four sizes of circular disturbed patches. We created the patches by mowing vegetation in an abandoned hay field in northern Ontario, Canada. The treatments had no effect on vole density, and there was no consistent relationship between vole activity and distance from the edge of disturbed patches. Incidental predation of sunflower seeds, our measure of vole foraging behaviour, declined linearly with increasing patch circumference (edge). Seed consumption by meadow voles, and predation by voles on lower food levels, correlates with the length of edge habitat rather than with the area disturbed. Adaptive behaviour can thereby explain edge effects that, under current priorities emphasizing area, would appear at odds with conservation ecology. [source] Functional MRI of the visual cortex and visual testing in patients with previous optic neuritisEUROPEAN JOURNAL OF NEUROLOGY, Issue 3 2002A. R. Langkilde The volume of cortical activation as detected by functional magnetic resonance imaging (fMRI) in the visual cortex has previously been shown to be reduced following optic neuritis (ON). In order to understand the cause of this change, we studied the cortical activation, both the size of the activated area and the signal change following ON, and compared the results with results of neuroophthalmological testing. We studied nine patients with previous acute ON and 10 healthy persons served as controls using fMRI with visual stimulation. In addition to a reduced activated volume, patients showed a reduced blood oxygenation level dependent (BOLD) signal increase and a greater asymmetry in the visual cortex, compared with controls. The volume of visual cortical activation was significantly correlated to the result of the contrast sensitivity test. The BOLD signal increase correlated significantly to both the results of the contrast sensitivity test and to the Snellen visual acuity. Our results indicate that fMRI is a useful method for the study of ON, even in cases where the visual acuity is severely impaired. The reduction in activated volume could be explained as a reduced neuronal input; however, the greater asymmetry might point to a cortical reorganization as a consequence of neuronal damage. Future fMRI studies in ON will add to the understanding of the neural adaptive behaviour following ON. [source] An observational measure of children's behavioural style: Evidence supporting a multi-method approach to studying temperamentINFANT AND CHILD DEVELOPMENT, Issue 2 2004Jennifer Karp Abstract This study demonstrates the potential utility of the Behavioural Style Observational System (BSOS) as a new observational measure of children's behavioural style. The BSOS is an objective, short and easy to use measure that can be readily adapted to a variety of home and laboratory situations. In the present study, 160 mother,child dyads from the Concordia Longitudinal Risk Project (CLRP) were observed during an 11-min behavioural sample. Videotaped interactions were coded using the BSOS for children's mood, activity level, vocal reactivity, approach to toys, mood consistency and adaptability. Comparisons between the BSOS observational ratings and mothers' ratings of the child on the EAS Temperament Survey (EAS) provided support for modest congruence between these two measurement systems, and revealed a differential predictive pattern of children's functioning. Specifically, the observation-based BSOS predicted children's cognitive performance and adaptive behaviour during testing, whereas the mother-rated EAS predicted maternal ratings of children's internalizing and externalizing behaviour problems. Both measures were found to independently predict mothers' ratings of parenting stress. Overall, the findings imply that neither observational measures nor maternal ratings alone are sufficient to understand children's behavioural style, and that comprehensive evaluations of children's temperament should optimally include both types of measures. Copyright İ 2004 John Wiley & Sons, Ltd. [source] Active Support, Participation and DepressionJOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES, Issue 4 2010Roger J. Stancliffe Background, Staff training in Active Support is designed to enable direct support staff to increase the engagement and participation of people with intellectual disabilities in a range of daily activities. Method, Residents (n = 41) and staff of nine group homes participated. The effectiveness of Active Support was evaluated with a pre-test:post-test design, using a number of standardized assessments and other questionnaires, with group home staff as informants. These assessments were conducted before Active Support training and an average of 6.5 months later. Results, Following implementation of Active Support residents experienced significant increases in domestic participation and adaptive behaviour. There were significant decreases in internalized challenging behaviour, overall challenging behaviour and depression. There was no significant pre,post change in other forms of challenging behaviour. Conclusions, Our findings confirm and extend previous Active Support research showing that implementation of Active Support is followed by increased resident participation in activities. The significant improvements in adaptive behaviour, challenging behaviour and depression are of particular interest as the present study is among the first to report such effects. The study's limitations are discussed. [source] The Reliability, Validity and Practical Utility of Measuring Supports using the I-CAN Instrument: Part IIJOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES, Issue 4 2009Vivienne C. Riches Background, There is an urgent need for developing reliable, valid and practical instruments that assess and classify the support needed by persons with disability to function in their chosen living, working and social environments. I-CAN is an instrument that addresses the frequency and level of support needed (not individual skills or deficits) for each individual with a disability. Method, Studies were conducted to assess the test,retest reliability and inter-rater reliability. Concurrent validity was investigated by exploring the relationship between the I-CAN domain scales and the Inventory for Client and Agency Planning (ICAP) (Bruininks et al. 1986) and the Quality of Life Questionnaire (QOL-Q) (Schalock & Keith 1993). Predictive validity studies were undertaken using day- and night-time support hours. Regression analyses were run using these measures with I-CAN domain scales. Two independent studies were also conducted to ascertain the practical utility of the instrument. Results, The I-CAN instrument demonstrated excellent inter-rater and test,retest reliability in the Activities and Participation domains. Low-to-moderate test,retest results in Physical Health, Mental Emotional Health and Behaviour domains were tracked to actual change in support needs in these areas. Validity proved acceptable. The relationships between I-CAN domain scales and adaptive behaviour were mixed but in the expected direction. Low-to-moderate correlation coefficients were evident between the I-CAN scales and the QOL-Q Total, but greater support needed in certain domains was associated with less empowerment and independence, and less community integration and social belonging. Attempts to explain current support hours against the I-CAN scales were disappointing and suggest that a number of other factors apart from individual support need to play a significant role. There was general satisfaction with the assessment process from stakeholders and participant groups. Conclusions, I-CAN is a reliable, valid and user-friendly instrument for assessing the support needs of people with disabilities. It uses a process that involves the persons with disability, their family and friends and staff as appropriate. It is also apparent that the current provision of paid support hours by agencies is a complex phenomenon that is not based solely on individual support needs. Further research is warranted on the influence of the environment and the perceptions of need for support based on negotiable and non-negotiable support needs. [source] Age Recognition in Adults with Intellectual Disabilities: a Literature Review and an Exploratory StudyJOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES, Issue 3 2000Dorothy M. Bell The ability of children to classify accurately their own ages and the ages of others has been the subject of very limited research. However, the literature is largely in agreement on there being progressive increases in skill with chronological age, although there is disagreement on the age at which this ability becomes well developed. The processes look similar in the field of intellectual disabilities, although this area is extremely under-researched. Key factors may include age, the amount of time spent in institutions (e.g. long-term hospitals for people with intellectual disabilities), developmental level and IQ. The present paper provides a review of the relevant literature and an exploratory study investigating the age recognition of self and colleagues in a group of 20 adults with intellectual disability, some from within what has been a major hospital for people with intellectual disabilities and some from the wider community. Measures of age recognition using photographs, as well as standardized measures of intellectual ability and social adaptive behaviour, were administered, and correlations were found between the ability to recognize age in others and developmental age, and also IQ. Success on the task of age discrimination appears to be more likely if the IQ of the individual is around 60,65 or above, and if the person shows social adaptive behaviour equivalent to 8 or 9 years of age and over. Also included in the study was a task in which only the discrimination of whether the photographs were of adults or children was required, and this proved to be a simpler process for the participants. The present study also demonstrates some of the discriminative stimuli used by adults with intellectual disabilities to ascertain the approximate age of a person. [source] Social learning and life skills training for hatchery reared fishJOURNAL OF FISH BIOLOGY, Issue 3 2001C. Brown With the stress placed on our natural resources, many fisheries increasingly rely on restocking from hatchery-reared sources in an attempt to maintain commercially viable populations. However, the mortality rates of hatchery-reared fishes during the period directly following release are very high. The successful development of restocking programs is consequently dependent upon production and release strategies that lead to improved migratory, antipredator and feeding behaviour in hatchery fish. While relevant individual experience prior to release might improve performance, social learning potentially provides a process whereby fish can acquire locally adaptive behaviour rapidly and efficiently. It is now well over a decade since Suboski & Templeton (1989) raised the possibility of using social learning processes to improve the post-release survival of hatchery-reared fishes. This period has witnessed considerable progress in the understanding of how social learning operates in fish populations. We review new methods and recent findings that suggest how social learning protocols could realistically be applied on a large scale to enhance the viability of hatchery fish prior to their release into the wild. We also suggest a practical pre-release training protocol that may be applied at the hatchery level. [source] Neuropsychological components of intellectual disability: the contributions of immediate, working, and associative memoryJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 5 2010Jamie O. Edgin Abstract Background Efficient memory functions are important to the development of cognitive and functional skills, allowing individuals to manipulate and store information. Theories of memory have suggested the presence of domain-specific (i.e. verbal and spatial) and general processing mechanisms across memory domains, including memory functions dependent on the prefrontal cortex (PFC) and the hippocampus. Comparison of individuals who have syndromes associated with striking contrasts in skills on verbal and spatial tasks [e.g. Down syndrome (DS) and Williams syndrome (WS)] allows us to test whether or not these dissociations may extend across cognitive domains, including PFC and hippocampal memory processes. Methods The profile of memory function, including immediate memory (IM), working memory (WM) and associative memory (AM), was examined in a sample of adolescents and young adults with DS (n = 27) or WS (n = 28), from which closely CA- and IQ-matched samples of individuals with DS (n = 18) or WS (n = 18) were generated. Relations between memory functions and IQ and adaptive behaviour were also assessed in the larger sample. Results Comparisons of the two matched groups indicated significant differences in verbal IM (DS < WS), spatial IM (DS > WS) and spatial and verbal AM (DS > WS), but no between-syndrome differences in WM. For individuals with DS, verbal IM was the most related to variation in IQ, and spatial AM related to adaptive behaviour. The pattern was clearly different for individuals with WS. Verbal and spatial AM were the most related to variation in IQ, and verbal WM related to adaptive behaviour. Conclusions These results suggest that individuals with these two syndromes have very different patterns of relative strengths and weaknesses on memory measures, which do not fully mirror verbal and spatial dissociations. Furthermore, different patterns of memory dysfunction relate to outcome in individuals with each syndrome. [source] Parenting stress in mothers of adults with an intellectual disability: parental cognitions in relation to child characteristics and family supportJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 12 2009C. Hill Abstract Background There is a body of evidence that indicates that the cognitions of parents of children with intellectual disabilities (ID) play an important role in influencing parental stress. However, there is a paucity of evidence about the experience of parents of adult children with ID. This study sought to apply a model of parenting stress to mothers of adults with ID. Of particular interest were the parental cognitions of parenting self-esteem and parental locus of control. Method Face-to face interviews were administered with 44 mothers of adults with ID. They completed the Vineland Adaptive and Maladaptive Behaviour Scale, the Family Support Scale, the Parenting Sense of Competence Scale, a shortened version of the Parental Locus of Control Scale and the Parenting Stress Index. Results Correlations were observed between parenting stress and the other study variables. Regression analysis revealed that parental cognitive variables predicted 61% of the variance in parenting stress. Parenting satisfaction, a subscale of the measure of parenting sense of competence, mediated the relationships between adaptive behaviour and parenting stress and between family support and parenting stress. Conclusions These results indicate the importance of cognitive variables in the stress of mothers of adults with ID. Potential avenues of future research might focus on the experience of fathers and the impact of positive perceptions as a cognitive factor. [source] Evaluating the inter-respondent (consumer vs. staff) reliability and construct validity (SIS vs.JOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 4 2009Vineland) of the Supports Intensity Scale on a Dutch sample Abstract Background Despite various reliability studies on the Supports Intensity Scale (SIS), to date there has not been an evaluation of the reliability of client vs. staff judgments. Such determination is important, given the increasing consumer-driven approach to services. Additionally, there has not been an evaluation of the instrument's construct validity on a non-English speaking sample. This is important as the SIS is currently translated into 13 languages. Method Data were collected in two different samples, using the Dutch translation of the SIS and the Vineland-Z. Results There was a significant correlation between ratings of staff and consumers on the SIS; however, the relationship between the mean scores of consumer and staff responses indicated significant differences in staff and consumer scores. All correlations between the Vineland-Z domains and the SIS subscales were significant and negative, ranging from ,0.37 to ,0.89. Conclusions Analyses of the inter-respondent reliability suggest that one needs to consider the source of information regarding needed supports carefully. The significant negative correlations between SIS and Vineland-Z reflect that the SIS is measuring a different construct (needed support) than the Vineland-Z (adaptive behaviour). The results of the two studies provide additional support for the etic (universal) properties of the SIS, as both hypotheses were confirmed. In conclusion, SIS users are provided with a wealth of information that can be used for multiple purposes. [source] Self-determination, social abilities and the quality of life of people with intellectual disabilityJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 11 2007L. Nota Summary Background The international literature has documented that self-determination is impacted by environmental factors, including living or work settings; and by intraindividual factors, including intelligence level, age, gender, social skills and adaptive behaviour. In addition, self-determination has been correlated with improved quality of life (QoL). This study sought to contribute to the growing literature base in this area by examining the relationship among and between personal characteristics, self-determination, social abilities and the environmental living situations of people with intellectual disabilities (ID). Methods The study involved 141 people with ID residing in Italy. Healthcare professionals and social workers who had known participants for at least 1 year completed measures of self-determination, QoL and social skills. Analysis of variance was conducted to verify whether different levels of intellectual impairment were associated with different degrees of the dependent variables. The Pearson product,moment correlation was used to examine any relationships among dependent variables and IQ scores. Finally, discriminant function analysis was used to examine the degree to which IQ score, age, self-determination and social abilities predicted membership in groups that were formed based on living arrangement, and on QoL status (high vs. low). Results The anova determined, as expected, that participants with more severe ID showed the lowest levels of self-determination, QoL and social abilities. Discriminant function analysis showed that (a) individuals attending day centres were distinguished from those living in institutions in that they were younger and showed greater autonomy of choice and self-determination in their daily activities; (b) basic social skills and IQ score predicted membership in the high or low QoL groups; and (c) the IQ score predicted membership in the high or low self-determination groups. A manova conducted to examine gender- and age-level differences on self-determination found gender differences; women had higher self-determination scores than men. Conclusions These findings contribute to an emerging knowledge base pertaining to the role of intraindividual and environmental factors in self-determination and QoL. In general, the study replicated findings pertaining to the relative contribution of intelligence to self-determination and QoL, added information about the potential contribution of social abilities, and pointed to the potentially important role of opportunities to make choices as a particularly important aspect of becoming more self-determined, at least in the context of residential settings. [source] Intellectual and adaptive behaviour functioning in pantothenate kinase-associated neurodegenerationJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 6 2007K. Freeman Abstract Background Pantothenate kinase-associated neurodegeneration (PKAN), an extremely rare autosomal recessive disorder resulting in iron accumulation in the brain, has a diverse phenotypic expression. Based on limited case studies of one or two patients, intellectual impairment is considered part of PKAN. Investigations of cognitive functioning have utilized specific neuropsychological tests, without attention to general intellectual skills or adaptive behaviour. Methods Sixteen individuals with PKAN completed measures of global intellectual functioning, and participants or care providers completed measures of adaptive behaviour skills and day-to-day functional limitations. Clinicians provided global ratings of condition severity. Results Testing with standardized measures documented varied phenotypic expression, with general cognitive skills and adaptive behaviour ranging from high average to well below average. Age of disease onset correlated with measures of intellectual functioning, adaptive functioning and disease severity. Conclusions Findings support previously described clinical impressions of varied cognitive impairment and the association between age of onset and impairment. Further, they add important information regarding the natural history of the disease and suggest assessment strategies for use in treatment trials. [source] Syndrome specificity and behavioural disorders in young adults with intellectual disability: cultural differences in family impactJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 3 2006J. Blacher Background This study examined whether behaviour problems and adaptive behaviour of low functioning young adults, and well-being of their families, varied by diagnostic syndrome [intellectual disability (ID) only, cerebral palsy, Down syndrome, autism], as well as by cultural group. Methods Behaviour disorders in young adults with moderate to severe ID were assessed from information provided by 282 caregivers during in-home interviews. The sample consisted of 150 Anglo participants, and 132 Latino, primarily Spanish-speaking, participants drawn from Southern California. Results Behaviour disorders and maternal well-being showed the same pattern across disability syndromes. Autism was associated with the highest scores in multiple behaviour problem areas as well as maternal reports of lower well-being. Down syndrome was associated with the lowest behaviour problem scores and the highest maternal well-being. When behaviour problems were controlled for, diagnostic groups accounted for no additional variance in maternal stress or depression. The pattern of behaviour problems and well-being did not differ by sample (Anglo vs. Latino), although level on well-being measures did. Latina mothers reported significantly higher depression symptoms and lower morale, but also higher positive impact from their child than did Anglo mothers. Conclusions Caregivers of young adults with autism report more maladaptive behaviour problems and lower personal well-being, or stress, relative to other diagnostic groups, regardless of cultural group. However, cultural differences exist in caregiver reports of depression, morale, and positive perceptions. Implications for service provision aimed at families of children with challenging behaviour problems are discussed in the context of culture. [source] Mothers' expressed emotion towards children with and without intellectual disabilitiesJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 7 2004A. Beck Objectives To identify factors associated with maternal expressed emotion (EE) towards their child with intellectual disability (ID). Design and method A total of 33 mothers who had a child with ID and at least one child without disabilities between the ages of 4 and 14 years participated in the study. Mothers completed self-assessment questionnaires which addressed their sense of parenting competence, beliefs about child-rearing practices, and their reports of behavioural and emotional problems of their child with ID. Telephone interviews were conducted to assess maternal EE towards the child with ID and towards a sibling using the Five Minute Speech Sample (FMSS; Magana et al. 1986), and also to assess the adaptive behaviour of the child with ID using the Vineland Adaptive Behaviour Scale (VABS; Sparrow et al. 1984). Results Mothers with high EE towards their child with ID were more satisfied with their parenting ability, and their children had more behaviour problems. Analysis of differential maternal parenting, through comparisons of EE towards their two children, showed that mothers were more negative towards their child with ID for all domains of the FMSS except dissatisfaction. Conclusions A small number of factors associated with maternal EE towards children with ID were identified. Differences in maternal EE towards their child with ID and their other child suggest that EE is child-driven rather than a general maternal characteristic. Implications of the data for future research are discussed. [source] Responsiveness to staff support: evaluating the impact of individual characteristics on the effectiveness of active support training using a conditional probability approachJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 8 2002C. Smith Abstract Background Active support training was fully conducted in 38 community houses accommodating 106 adults with intellectual disabilities (ID; group 1), but not in a further 36 accommodating 82 adults with ID (group 2). The aims of the present study were to analyse whether staff became more effective in supporting resident activity after the implementation of active support, and whether there was evidence of differential responsiveness by people with differing status in relation to adaptive behaviour, psychiatric diagnosis, challenging behaviour or autism. Methods Observations of staff:resident interaction and resident engagement in activity were taken before and after active support training. Changes in Yule's Q statistics, indicating the likelihood that resident engagement in activity followed staff giving residents verbal instruction or non-verbal assistance, were compared for the two groups. In addition, changes in similar statistics were compared for residents within group 1: (1) with Adaptive Behaviour Scale (ABS) scores above and below 180; and (2) with and without severe challenging behaviour, the triad of social impairments and mental illness. Results Yule's Q for engagement given non-verbal assistance significantly increased post-training among group 1, but not among group 2. Similar significant increases were found among group 1 residents with ABS scores below 180 without challenging behaviour, with and without the triad of social impairments, and without mental illness, but not with an ABS score above 180, with challenging behaviour and with mental illness. Conclusion The present analysis reinforces previous studies on the effectiveness of active support training for adults with more severe ID (i.e. with ABS scores below 180). Active support was as effective for people with the triad of social impairments as for those without it. However, the effectiveness of support offered to people with challenging behaviour or mental illness did not significantly increase. [source] Blunted Pituitary-Adrenocortical Stress Response in Adult Rats Following Neonatal Dexamethasone TreatmentJOURNAL OF NEUROENDOCRINOLOGY, Issue 10 2000K. Felszeghy Abstract Glucocorticoids have a prominent impact on the maturation of the stress-related neuroendocrine system and on the postnatal establishment of adaptive behaviour. The present study aimed at investigating the stress responsiveness of the hypothalamo-pituitary-adrenocortical (HPA) axis in young and adult rats after neonatal treatment with the synthetic glucocorticoid agonist, dexamethasone. Newborn male Wistar rats were injected s.c. with 1 µg/g dexamethasone on postnatal days 1, 3 and 5. Circulating adrenocorticotropic hormone (ACTH) and corticosterone concentrations were measured in the resting state and following a 30-min cold stress at the age of 10 days, as well as after a 30-min restraint stress at the age of 14 weeks. Also in adults, pituitary and adrenocortical hormone responsiveness was evaluated after i.v. administration of 2 µg/kg corticotropin releasing hormone (CRH). In addition, glucocorticoid (GR) and mineralocorticoid receptor (MR) binding capacities were assessed in the pituitaries of adult rats. The results showed that at day 10 basal ACTH concentration was elevated while the cold stress-evoked ACTH response was attenuated in the dexamethasone-treated rats. As adults, treated rats showed a suppressed elevation of both ACTH and corticosterone plasma cncentrations in response to restraint, while basal hormonal concentrations were not altered. There was no difference in the magnitude of the CRH-induced elevation of ACTH and corticosterone concentrations initially; however, the dexamethasone-treated animals showed a prolonged secretion of both hormones. These animals also showed a selective decrease in pituitary GR binding capacity. Neonatal dexamethasone treatment strongly suppressed body weight gain, and adrenal and thymus weights in the early phase of postnatal development. By adulthood, the body and adrenal weights were normalized while thymus weight was greater than in controls. These findings indicate that neonatal dexamethasone treatment permanently alters HPA axis activity by reducing stress responses to cold and restraint probably through supra-pituitary actions, and by decreasing the effectiveness of feedback through a diminished GR binding in the pituitary. [source] Habitat-dependent foraging in a classic predator,prey system: a fable from snowshoe haresOIKOS, Issue 2 2005Douglas W. Morris Current research contrasting prey habitat use has documented, with virtual unanimity, habitat differences in predation risk. Relatively few studies have considered, either in theory or in practice, simultaneous patterns in prey density. Linear predator,prey models predict that prey habitat preferences should switch toward the safer habitat with increasing prey and predator densities. The density-dependent preference can be revealed by regression of prey density in safe habitat versus that in the riskier one (the isodar). But at this scale, the predation risk can be revealed only with simultaneous estimates of the number of predators, or with their experimental removal. Theories of optimal foraging demonstrate that we can measure predation risk by giving-up densities of resource in foraging patches. The foraging theory cannot yet predict the expected pattern as predator and prey populations covary. Both problems are solved by measuring isodars and giving-up densities in the same predator,prey system. I applied the two approaches to the classic predator,prey dynamics of snowshoe hares in northwestern Ontario, Canada. Hares occupied regenerating cutovers and adjacent mature-forest habitat equally, and in a manner consistent with density-dependent habitat selection. Independent measures of predation risk based on experimental, as well as natural, giving-up densities agreed generally with the equal preference between habitats revealed by the isodar. There was no apparent difference in predation risk between habitats despite obvious differences in physical structure. Complementary studies contrasting a pair of habitats with more extreme differences confirmed that hares do alter their giving-up densities when one habitat is clearly superior to another. The results are thereby consistent with theories of adaptive behaviour. But the results also demonstrate, when evaluating differences in habitat, that it is crucial to let the organisms we study define their own habitat preference. [source] Zerstört der Sozialstaat die Familie?PERSPEKTIVEN DER WIRTSCHAFTSPOLITIK, Issue 2 2008Evelyn Korn Accordingly, all social policy measures should support (or at least not disadvantage) marriages and families. This article shows that supporting marriages and supporting families are conflicting aims. It shows that measures which are intended to support families in raising children induce adaptive behaviour of (potential) parents that erodes marriage as an institution. In consequence, female incentives to bear children might be reduced by measures that were intended to augment them. [source] I've Heard About , (A Flat, Fat, Growing Urban Experiment): Extract of Neighbourhood ProtocolsARCHITECTURAL DESIGN, Issue 4 2009François Roche Abstract Urban models are conventionally planned and intended to control urban systems. François Roche's vision is to the contrary: it is for an unpredictable organic urbanism. A biostructure develops its own adaptive behaviour, based on growth scripts and open algorithms. It is entirely reflexive, responding to human occupation and expression rather than being managed or operated at human will. Copyright İ 2009 John Wiley & Sons, Ltd. [source] A prospective study on the persistence of infant crying, sleeping and feeding problems and preschool behaviourACTA PAEDIATRICA, Issue 2 2010G Schmid Abstract Aim:, To determine the persistence of regulatory problems (RP), i.e. excessive crying (>3 months of age), feeding and sleeping difficulties from infancy to preschool age, and to evaluate whether RP at 5 months are predictive of preschool adaptive behaviour and social skills. Method:, A prospective population study of newborns admitted to neonatal care. RP at 5, 20 and 56 months of age were obtained via parent interviews and neurological examination and preschool adaptive behaviour and social skills by parent ratings. Logistic and linear regression analyses were conducted and controlled for psychosocial and neurological factors. Results:, More than half of the sample had RP at least at one measurement point. In about 8% of infants, RP persisted across the preschool years. Multiple RP and feeding problems increased the odds of eating problems at 20 and 56 months. Persistent RP and feeding problems were predictive of deficits in preschool adaptive behaviour and social skills. In addition, sex differences were found. Conclusions:, Multiple RP and feeding problems had the highest stability. Persistent RP were predictive of adverse social and adaptive behaviour. Understanding of the aetiology may help to prevent persistent RP [source] Physiological functions of glucose-inhibited neuronesACTA PHYSIOLOGICA, Issue 1 2009D. Burdakov Abstract Glucose-inhibited neurones are an integral part of neurocircuits regulating cognitive arousal, body weight and vital adaptive behaviours. Their firing is directly suppressed by extracellular glucose through poorly understood signalling cascades culminating in opening of post-synaptic K+ or possibly Cl, channels. In mammalian brains, two groups of glucose-inhibited neurones are best understood at present: neurones of the hypothalamic arcuate nucleus (ARC) that express peptide transmitters NPY and agouti-related peptide (AgRP) and neurones of the lateral hypothalamus (LH) that express peptide transmitters orexins/hypocretins. The activity of ARC NPY/AgRP neurones promotes food intake and suppresses energy expenditure, and their destruction causes a severe reduction in food intake and body weight. The physiological actions of ARC NPY/AgRP cells are mediated by projections to numerous hypothalamic areas, as well as extrahypothalamic sites such as the thalamus and ventral tegmental area. Orexin/hypocretin neurones of the LH are critical for normal wakefulness, energy expenditure and reward-seeking, and their destruction causes narcolepsy. Orexin actions are mediated by highly widespread central projections to virtually all brain areas except the cerebellum, including monosynaptic innervation of the cerebral cortex and autonomic pre-ganglionic neurones. There, orexins act on two specific G-protein-coupled receptors generally linked to neuronal excitation. In addition to sensing physiological changes in sugar levels, the firing of both NPY/AgRP and orexin neurones is inhibited by the ,satiety' hormone leptin and stimulated by the ,hunger' hormone ghrelin. Glucose-inhibited neurones are thus well placed to coordinate diverse brain states and behaviours based on energy levels. [source] Parenting and child behaviour problems: a longitudinal analysis of non-shared environmentINFANT AND CHILD DEVELOPMENT, Issue 2 2009Paula Y. Mullineaux Abstract This study examined potential non-shared environmental processes in middle childhood by estimating statistical associations between monozygotic (MZ) twin differences in externalizing and internalizing problems and positive social engagement, and differential maternal positivity and negativity, over 1 year. Seventy-seven pairs of identical twins participated (M=6.08-years old, 65% male) in two annual home visits. Observers' ratings and maternal reports were gathered. At both assessments, the twin who showed more conduct problems (maternal report and observers' ratings) and less positive social engagement (positive affect, responsiveness) received more maternal negativity and less maternal warmth (self-reports and observers' ratings), relative to his or her genetically identical co-twin. The same patterns held over time, for the associations between change in differential MZ twin conduct problems and social engagement and change in differential maternal behaviour. Effects for child internalizing problems were not consistent within or across raters. Overall, these results indicated that differential maternal warmth and negativity,self-perceived and observed by others,are important aspects of sibling differentiation for both problematic and adaptive behaviours during middle childhood. Copyright İ 2009 John Wiley & Sons, Ltd. [source] The impact of predation risk from small mustelids on prey populationsMAMMAL REVIEW, Issue 3-4 2000Kai Norrdahl ABSTRACT Small mustelids are ,snake-like' mammals adapted to hunt small rodents, which are their principal prey, in tunnels leaving practically no refuge for the prey. Prey rodents have adaptive behaviours to situations where the predation risk from mustelids is high, including reduced activity and escape by climbing. Small mustelids may affect prey population dynamics directly through killing (increased mortality) and/or indirectly through behavioural changes in prey as a response to the presence of mustelids (predation risk). The Predator-Induced Breeding Suppression hypothesis (PIBS) states that a trade-off between survival and reproduction should lead to delayed breeding under temporarily high predation risk, so that the mere presence of predators may reduce reproductive output. Current results suggest that small mustelids mainly affect prey population growth rate directly through killing. In many cyclic rodent populations, small mustelid predation is a major mortality factor, and experimental evidence supports the hypothesis that these predators drive prolonged summer declines in prey. In contrast, the evidence for PIBS is controversial. Experimental evidence shows that the indirect effects of small mustelids on prey populations are negligible during the best breeding season. However, in other seasons, the presence of predators may indirectly affect prey populations, although this has not been studied experimentally. Prey rodents may decrease mobility as a response to high predation risk by small mustelids, and this reduction in mobility decreases feeding. Reduced feeding affects the energy reserves of voles, and may delay maturation or lower the size of the first litter. [source] Giving voice to experiences: parental maltreatment of black children in the context of societal racismCHILD & FAMILY SOCIAL WORK, Issue 4 2002Claudia Bernard ABSTRACT This paper seeks to explore the ways in which black children who have been maltreated within their families come to voice to tell their stories. A discussion of black children's recovery from maltreatment necessitates understanding how they interpret and name their experiences as abusive. Research indicates that while many factors mediate the effects of abuse on children's development, telling your story about childhood trauma is critical in the healing process for promoting psychological well-being. However, what does the naming and speaking of trauma entail for black children when the broader context of their lived realities is embedded in racism that confers on them a stigmatized status? Where black children's lived experiences encompass the complexity of societal racism as a mutually reinforcing and contradictory reality in their lives, their capacity to name the maltreatment they experience will be particularly problematic. Essentially, parents' issues silence children and can encourage them to block out painful emotions, ultimately putting their emotional and psychological well-being at risk. Taking race and gender as benchmarks for analysis, the complexities involved in giving voice to childhood maltreatment are discussed to consider how these dynamics contribute to black children's resilience and adaptive behaviours in the aftermath of abuse. [source] | |||||||||||||||||||