The non-ideal problem behavior using a dynamic vibration absorber with nonlinear essential stiffness and timedependent damping properties

The purpose of this study is to develop a dynamic vibration absorber using viscoelastic material with nonlinear essential stiffness and time-dependent damping properties for a non-ideal vibrating system with Sommerfeld effect, resonance capture, and jump phenomenon. The absorber is a mass-bar subsystem that consists of a viscoelastic bar with memory attached to mass, in which the internal dissipative forces depend on current, deformations, and its operational frequency varies with limited temperature. The non-ideal vibrating system consists of a linear (nonlinear) oscillator (plane frame structure) under excitation, via spring connector, of a DC-motor with limited power supply. A viscoelastic dynamic absorber modeled with elastic stiffness essentially nonlinearities was developed to further reduce the Sommerfeld effect and the response of the structure. The numerical results show the performance of the absorber on the non-ideal system response through the resonance curves, time histories, and Poincarésections. Furthermore, the structure responses using the viscoelastic damper with and without memory were studied. © IMechE 2012.

Caretaking behavior among siblings in children's shelters

Este estudo analisou 742 eventos envolvendo comportamento de cuidado entre crianças abrigadas com e sem irmão na mesma instituição. Foram aplicados testes estatísticos para avaliação intergrupal na comparação entre os sujeitos focais. As crianças com irmão manifestaram a maior proporção desses comportamentos e foram dirigidos principalmente a parceiros não-Irmãos (companheiros de dormitório) ou adultos (cuidadores). O estudo revelou ainda que o comportamento Brincar de cuidar foi mais freqüente no grupo de crianças Com Irmão na instituição enquanto que entre os participantes Sem Irmão predominou Estabelecer contato afetuoso e comportamentos direcionados mais a adultos do que aos pares. Conclui-se que o comportamento de cuidado está presente entre irmãos, mas assume formas particulares em razão da complexa dinâmica social que caracteriza o ambiente pesquisado.

Voice disorders in children and its relationship with auditory, acoustic and vocal behavior parameters

Objective: Parameters to distinguish normal from deviant voices in early childhood have not been established. The current study sought to auditorily and acoustically characterize voices of children, and to study the relationship between vocal behavior reported by teachers and the presence of vocal aberrations. Methods: One hundred children between four and 6 years and 11 months, who attended early childhood educational institutions, were included. The sample comprised 50 children with normal voices (NVG) and 50 with deviant voices (DVG) matched by gender and age. All participants were submitted to auditory and acoustic analysis of vocal quality and had their vocal behaviors assessed by teachers through a specific protocol. Results: DVG had a higher incidence of breathiness (p < 0.001) and roughness (p < 0.001), but not vocal strain (p = 0.546), which was similar in both groups. The average F-0 was lower in the DVG and a higher noise component was observed in this group as well. Regarding the protocol used "Aspects Related to Phonotrauma - Children's Protocol", higher means were observed for children from DVG in all analyzed aspects and also on the overall means (DVG = 2.15; NVG = 1.12, p < 0.001). In NVG, a higher incidence of vocal behavior without alterations or with discrete alterations was observed, whereas a higher incidence of moderate, severe or extreme alterations of vocal behavior was observed in DVG. Conclusions: Perceptual assessment of voice, vocal acoustic parameters (F-0, noise and GNE), and aspects related to vocal trauma and vocal behavior differentiated the groups of children with normal voice and deviant voice. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

Problem behavior of dementia patients predicts low-grade hypercoagulability in spousal caregivers

Low-grade hypercoagulability might be one pathway to explain how the chronic stress of dementia caregiving increases cardiovascular disease risk, but the specific aspects of caregiver stress that elicit hypercoagulability are elusive. We hypothesized that dementia patients' problem behaviors and negative reactions of caregivers to these behaviors would relate to hypercoagulability in caregivers.

Feature Versus Spatial Strategies by Orangutans (Pongo abelii) and Human Children (Homo sapiens) in a Cross-Dimensional Task

Despite the fact that photographic stimuli are used across experimental contexts with both human and nonhuman subjects, the nature of individuals' perceptions of these stimuli is still not well understood. In the present experiments, we tested whether three orangutans and 36 human children could use photographic information presented on a computer screen to solve a perceptually corresponding problem in the physical domain. Furthermore, we tested the cues that aided in this process by pitting featural information against spatial position in a series of probe trials. We found that many of the children and one orangutan were successfully able to use the information cross-dimensionally; however, the other two orangutans and almost a quarter of the children failed to acquire the task. Species differences emerged with respect to ease of task acquisition. More striking, however, were the differences in cues that participants used to solve the task: Whereas the orangutan used a spatial strategy, the majority of children used a feature one. Possible reasons for these differences are discussed from both evolutionary and developmental perspectives. The novel results found here underscore the need for further testing in this area to design appropriate experimental paradigms in future comparative research settings.

Adaptive and Maladaptive Correlates of Repetitive Behavior and Restricted Interests in Persons with Down Syndrome and Developmentally-Matched Typical Children: A Two-Year Longitudinal Sequential Design

We examined the course of repetitive behavior and restricted interests (RBRI) in children with and without Down syndrome (DS) over a two-year time period. Forty-two typically-developing children and 43 persons with DS represented two mental age (MA) levels: `` younger'' 2-4 years; `` older'' 5-11 years. For typically developing younger children some aspects of RBRI increased from Time 1 to Time 2. In older children, these aspects remained stable or decreased over the two-year period. For participants with DS, RBRI remained stable or increased over time. Time 1 RBRI predicted Time 2 adaptive behavior (measured by the Vineland Scales) in typically developing children, whereas for participants with DS, Time 1 RBRI predicted poor adaptive outcome (Child Behavior Checklist) at Time 2. The results add to the body of literature examining the adaptive and maladaptive nature of repetitive behavior.

The additive and interactive roles of aggression, prosocial behavior, and social preference in predicting resource control in young children

Distinguishing between physical and social aggression, this study examined whether the predictive effect of aggression on resource control a) is moderated by prosocial behavior and b) corresponds to a linear or a curvilinear trend. Moderating effects of children’s social preference among peers and child sex in this context were also tested. Based on a sample of 682 kindergarten children (348 girls; average age 72.7 months, 3.6 SD), multilevel regressions revealed additive linear effects of social preference and prosociality on resource control. Moderate (but not high) levels of social aggression also facilitated resource control for disliked children. There was no such threshold effect for well liked children, who increasingly controlled the resource the more socially aggressive they were. In contrast, physical aggression hampered resource control unless used very modestly. The present study has a number of positive features. First, the distinction between physical and social aggression improves our understanding of the relation between aggression and social competence and sketches a more differentiated picture of the role of different forms of aggression in resource control. Second, this study combines the concept of resource control with the concept of social preference and investigates curvilinear effects of aggression. Third, the direct observation of resource control in the Movie Viewer increases the internal validity of this study.

Sympathy, distress, and prosocial behavior of preschool children in four cultures

This study examined emotional responding (sympathy and distress) and prosocial behavior as well as their relations across four cultures in a specific context. Preschool children (N = 212) from two Western cultures, Germany and Israel, and two South-East Asian cultures, Indonesia and Malaysia, participated in this study. Children's emotional reactions and prosocial behavior were observed when interacting with an adult in a quasi-experimental situation. Results showed that children from the two South-East Asian cultures, as compared to children from the two Western cultures, displayed more self-focused distress and less prosocial behavior. Across cultures, a positive relation between sympathy and prosocial behavior and a negative relation between self-focused distress and prosocial behavior were found. The strengths of these relations were moderated by culture. These results are discussed with regard to their cultural meaning in the specific experimental situation as well as to general culture-specific characteristics.

Behavior Problems of Maltreated Children Receiving In-Home Child Welfare Services

This study evaluates the level of behavior problems in a previously little studied group—children with founded cases of abuse and neglect receiving child welfare services in their own homes. A sample of 149 maltreated children, living at home, were evaluated on the CBCL as they entered a service program to which they were referred by a large public child protective service system. These children were found to have elevated levels of behavior problems, with 43.6% scoring in the problematic range, a rate similar to children entering foster care. Practice and policy implications of these findings are discussed and highlighted.

Intensive Family Preservation in Children's Mental Health: Predictors of Placement

This article examines the predictors of placement following IFPSfor a sample of child mental health service recipients and their families. Risk and protective factors vary depending on the time frame under consideration. Immediately following service, children 's level of Social/Legal functioning, a previous group home placement, and the presence of mental health problems for other family members increase risk of placement, while the number of follow-up services serves to lessen risk. Three to six months after service, the presence of a child behavior presenting problem and a projected placement in foster care serve as protective factors, while two service targets, alcohol monitoring and time management, serve to increase risk. Appropriate use of results for program design and for structuring access to services is discussed.

Modification of aviary design reduces incidence of falls, collisions and keel bone damage in laying hens

Non-cage housing systems for laying hens such as aviaries provide greater freedom to perform species-specific behavior and thus are thought to improve welfare of the birds; however, aviaries are associated with a high prevalence of keel bone damage (fractures and deviations), which is a major welfare problem in commercial laying hens. Potential causes of keel bone damage are falls and collisions with internal housing structures that occur as birds move between tiers or perches in the aviary. The aim of this study was to investigate the scope for reducing keel bone damage by reducing falls and collisions through modifications of aviary design. Birds were kept in 20 pens in a laying hen house (225 hens per pen) that were assigned to four different treatments (n = 5 pens per treatment group) including (1) control pens and pens modified by the addition of (2) perches, (3) platforms and (4) ramps. Video recordings at 19, 22, 29, 36 and 43 weeks of age were used to analyze controlled movements and falls (including details on occurrence of collision, cause of fall, height of fall and behavior after fall) during the transitional dusk and subsequent dark phase. Palpation assessments (focusing on fractures and deviations) using 20 focal hens per pen were conducted at 18, 20, 23, 30, 37, 44, 52 and 60 weeks of age. In comparison to the control group, we found 44% more controlled movements in the ramp (P = 0.003) and 47% more controlled movements in the platform treatments (P = 0.014) as well as 45% fewer falls (P = 0.006) and 59% fewer collisions (P < 0.001) in the ramp treatment. There were no significant differences between the control and perch treatments. Also, at 60 weeks of age, 23% fewer fractured keel bones were found in the ramp compared with the control treatment (P = 0.0053). After slaughter at 66 weeks of age, no difference in keel bone damage was found between treatment groups and the prevalence of fractures increased to an average of 86%. As a potential mechanism to explain the differences in locomotion, we suggest that ramps facilitated movement in the vertical plane by providing a continuous path between the tiers and thus supported more natural behavior (i.e. walking and running) of the birds. As a consequence of reducing events that potentially damage keel bones, the installation of ramps may have reduced the prevalence of keel fractures for a major portion of the flock cycle. We conclude that aviary design and installation of specific internal housing structures (i.e. ramps and platforms) have considerable potential to reduce keel bone damage of laying hens in aviary systems.

Formative evaluation of a parental involvement program for obesity prevention with low-income elementary school children

This study addresses the responses to a postcard campaign with health messages targeting the parents of children in a sample of low-income elementary schools and assesses the feasibility and areas of possible improvements in such a project. The campaign was implemented in Spring 2009 with 4 th grade students (n=1070) in fifteen economically disadvantaged elementary schools in Travis County, Texas. Postcards were sent home with children, and parents filled out a feedback card that the children returned to school. Response data, in the form of self-administered feedback cards (n=2665) and one-on-one teacher interviews (n=8), were qualitatively analyzed using NVivo 8 software. Postcard reception and points of improvement were then identified from the significant themes that emerged including health, cessation or reduction of unhealthy behaviors, motivation, family, and the comprehension of abstract health concepts. ^ Responses to the postcard campaign were almost completely positive, with less than 1% of responses reporting some sort of dislike, and many parents reported a modification of their behavior. However, possible improvements that could be made to the campaign are: increased focus of the postcards on the parents as the target population, increased information about serving size, greater emphasis on the link between obesity and health, alteration of certain skin tones used in the graphical depiction of people on the cards, and smaller but more frequent incentives to return the feedback cards for the students. The program appears to be an effective method of communicating health messages to the parents of 4th grade children.^

Cyberbullying and school attachment: An analysis of the 2005-2006 U.S. health behavior in school-aged children (HBSC) study

Despite a lack of consistent research, the possible association between school attachment and cyberbullying suggests that targeting school attachment as a method of increasing help-seeking behaviors may be important in intervention strategies for cyberbullying. The present study sought to fill the gap in current literature by examining cyberbullying and school attachment in a nationally representative sample of U.S. adolescents, grades 6-10 (n=9,227). Results found that negative school attachment was significantly associated with greater odds of cyberbullying victimization (OR=4.71, p<0.001), perpetration (OR=2.95, p<0.001), and cyberbully-victim status (OR=3.38, p<0.001). After adjustment for confounding variables, cyberbullying victimization remained significant (OR=1.90, p=0.002). Overall, the present analyses suggest that higher negative school attachment may be associated with higher frequency of cyberbullying behaviors. These findings provide evidence for an association between school attachment and cyberbullying, and support considerations that improving school attachment may be a potential source of intervention against cyberbullying in an adolescent population.^