Concentric and eccentric shoulder rehabilitation biomechanics

The use of an impulse-momentum (IM) exercise technique was investigated for end-stage shoulder rehabilitation. The objectives of this study were to: (a) quantify the net shoulder joint forces and moments while using an IM system and (b) test the influence of gender and muscle loading type (concentric or eccentric) on kinetic and kinematic parameters. Fourteen healthy adults (eight males, six females) performed a repeated measures experiment on an instrumented device utilizing a cabled shuttle system. While maintaining 90 degrees of shoulder abduction and 90 degrees of elbow flexion, the subjects externally rotated their upper arm from 0 degrees to 90 degrees (concentric acceleration) and then internally rotated their upper arm back from 90 degrees to the 0 degrees position (eccentric deceleration). Shoulder joint forces and moments as well as rotational work and power were calculated using inverse dynamics (free-body forces and moments calculated at intersegmental joint centres). Overall concentric peak forces and moments were greater than eccentric peak forces and moments (P < 0.0001). Joint forces and moments reached a maximum during the initial phase of concentric loading (0 degrees to 45 degrees) compared with any other rotational position in the loading cycle (concentric 45 degrees to 90 degrees or eccentric 90 degrees to 0 degrees). The results also indicate that males experienced higher (P < 0.0001) average resultant peak joint forces (concentric 0 degrees to 45 degrees = 108.0 N and eccentric 90 degrees to 45 degrees = 87.2 N) than females (concentric 0 degrees to 45 degrees = 74.7 N and eccentric 45 degrees to 0 degrees = 56.0 N). In addition, males experienced higher (P < 0.0001) average resultant peak joint moments (concentric 0 degrees to 45 degrees = 30.4 N m and eccentric 45 degrees to 0 degrees = 21.0 N m) than females (concentric 0 degrees to 45 degrees = 19.7 N m and eccentric 45 degrees to 0 degrees = 12.8 N m).     

Parents' book-reading habits with their children.

Investigated the extent to which parents' teaching of children becomes less directive as a function of children's age and communicative status and relations between parents' interaction styles and children's verbal IQ. 120 families participated in the study. Each family included a target child between the ages of 3 yrs 6 mo and 5 yrs 8 mo, a mother, and a father. 60 families included a communicatively handicapped target child (CH), and 60 matched families had a noncommunicatively handicapped target child (NCH). Target children were divided into 2 age groups: 4-yr-olds and 5-yr-olds. Each parent engaged in a book-reading task with the target child. Parents' interactions with children were classified according to levels of cognitive demand and directiveness. The WPPSI was administered to all children. The Verbal IQ scale subscore was used as the criterion variable in the regression analyses. Results indicate that parents were generally more directive and less demanding with younger CH children than they were with older NCH children. Further, different types of parental interaction styles predicted CH and NCH children's IQ. Results are discussed in terms of L. Vygotsky's (1978) theory of the zone of proximal development. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

5-HTTLPR status moderates the effect of early adolescent substance use on risky sexual behavior.

Objective: A longitudinal, prospective design was used to investigate a moderation effect in the association between early adolescent substance use and risky sexual behavior 2 years later. A genetic vulnerability factor, a variable nucleotide repeat polymorphism (VNTR) in the promoter region of the serotonin transporter gene SLC6A4, known as 5-HTTLPR, was hypothesized to moderate the link between substance use at age 14 and risky sexual behavior at age 16. This VNTR has been associated with risk-taking behavior. Design: African American youths in rural Georgia (N = 185) provided 2 waves of data on their substance use and sexual behavior. Genetic data were obtained via saliva samples. Main Outcome Measures: Substance use and sexual risk behavior were assessed using youth self-report items developed for this investigation. Results: Multiple regression analyses indicated that the presence of 1 or 2 copies of the short allele of the VNTR interacted with substance use to predict sexual behavior. Substance use had little effect on sexual behavior for youths without the short allele; this effect was greatly increased for youths with the short allele. Conclusion: Genetic vulnerability affected the implications of early onset substance use for later sexual behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Smoke-free laws and secondhand smoke exposure in US non-smoking adults, 1999-2002

Objectives

To investigate the relationship between smoke‐free law coverage and secondhand smoke (SHS) exposure in the United States non‐smoking adult population.

Design

We used data from the 1999–2002 National Health and Nutrition Examination Survey, a cross‐sectional survey designed to monitor the health and nutritional status of the US population. Serum cotinine levels were available for 5866 non‐smoking adults from 57 survey locations. Each location was categorised into one of three groups indicating extensive, limited, and no coverage by a smoke‐free law.

Main outcome measures

The proportion of adults with SHS exposure, defined as having serum cotinine levels ⩾ 0.05 ng/ml.

Results

Among non‐smoking adults living in counties with extensive smoke‐free law coverage, 12.5% were exposed to SHS, compared with 35.1% with limited coverage, and 45.9% with no law. Adjusting for confounders, men and women residing in counties with extensive coverage had 0.10 (95% confidence interval (CI) 0.06 to 0.16) and 0.19 (95% CI 0.11 to 0.34) times the odds of SHS exposure compared to those residing in counties without a smoke‐free law.

Conclusions

These results support the scientific evidence suggesting that smoke‐free laws are an effective strategy for reducing SHS exposure.     

Families and risk: prospective analyses of familial and social influences on adolescent substance use.

Parental, peer, and older siblings' contributions to adolescents' substance use were investigated with 2 waves of panel data from 225 African American families. Structural equation modeling showed that older siblings' behavioral willingness (BW) to use substances at Time 1 (T1) predicted target adolescents' Time 2 (T2) use, controlling for other T1 variables. Regression analyses revealed an interaction between targets' and siblings' BW, such that targets were more likely to use at T2 if both they and their siblings reported BW at T1. This interaction was stronger for families living in high-risk neighborhoods. Finally, siblings' willingness buffered the impact of peer use on targets' later use: Low sibling BW was associated with less evidence of peer influence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Placement shift, sibling relationship quality, and child outcomes in foster care: A controlled study.

Sibling unity during family transitions is considered a protective factor for child behavior problems, but there is little empirical support for the widespread child protection policy of placing siblings together in foster care. In a prospective study of 156 maltreated children, siblings were classified in 1 of 3 placement groups: continuously together (n = 110), continuously apart (n = 22), and disrupted placement (siblings placed together were separated; n = 24). Changes in child adjustment as a function of sibling relationship and placement group were examined. Sibling positivity predicted lower child problems at follow-up (about 14 months later), while sibling negativity predicted higher child problems. Placement group did not affect child behavior problems at follow-up; however, compared to siblings in continuous placement (either together or apart), siblings in disrupted placement with high initial behavior problems were rated as having fewer problems at follow-up, while siblings in disrupted placement with low initial behavior problems were rated as having more problems at follow-up. These findings highlight the importance of considering relationships between siblings and the risk that one poses to another before early placement decisions are made. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuroimaging and frontal-subcortical circuitry in obsessive-compulsive disorder

BACKGROUND: Neuroimaging studies provide strong evidence that the pathophysiology of obsessive-compulsive disorder (OCD) involves abnormal functioning along specific frontal-subcortical brain circuits. METHOD: A literature search was carried out for all brain imaging studies of patients with OCD. We also reviewed the basic science literature on the functional neuroanatomy of cortico-basal ganglia circuits, and integrated this information with neuroimaging data in OCD to formulate a theoretical model of brain mediation of OCD symptoms and response to treatment. RESULTS: At least a subgroup of patients with OCD may have abnormal basal ganglia development. Functional neuroimaging studies indicate that OCD symptoms are associated with increased activity in orbitofrontal cortex, caudate nucleus, thalamus and anterior cingulate gyrus. CONCLUSIONS: OCD symptoms are mediated by hyperactivity in orbitofrontal-subcortical circuits, perhaps due to an imbalance of tone between direct and indirect striato-pallidal pathways. We present a model which describes how frontal-subcortical brain circuitry may mediate OCD symptomatology, and suggest a hypothesis for how successful treatments may ameliorate symptoms, via their effects on circuit activity.     

Synchrotron microradiography of temperature gradient zone melting in directional solidification

Using synchrotron microradiography, temperature gradient zone melting (TGZM) was observed in Sn-13 wt pct Bi alloy in real time during directional solidification. A significant amount of remelting was measured on the cold sides of the dendrite arms, whereas added solidification on the hot sides of the dendrite arms was observed during dendrite growth. Kinetics of TGZM was measured based on the real-time observations. TGZM had a significant effect on dendrite morphology during continuous cooling and holding within the solidification range. The presence of tertiary dendrite arms enhanced the rate of TGZM. Remelting also led to the disintegration of some secondary dendrite arms.     

Identifying patients with depression in the primary care setting: a more efficient method

OBJECTIVE: To determine if there is a core subset of depressive symptoms that could be used to efficiently diagnose depression after administering the 2-item PRIME-MD a screening questionnaire for depression. METHODS: One thousand patients selected randomly and by convenience from 4 primary care clinics were assessed by PRIME-MD and completed a questionnaire measuring the following validation variables: functional status and well-being, disability days, somatic symptoms, depression severity, suicidal thoughts, health care utilization, and the physician-patient relationship. RESULTS: Four symptoms (sleep disturbance, anhedonia, low self-esteem, and decreased appetite) accounted for virtually all the depression symptom-related variance in functional status and well-being, with 8.3% of patients having 2 of these symptoms and 8.2% having 3 or 4 of these symptoms. There was excellent agreement between diagnosis based on core symptoms and major depression (K= 0.77; overall accuracy rate, 94%). There were significant differences (P<.001) among patients with negative depression screen, 0 to 1, 2, and 3 to 4 core symptoms with scores on each of the validation variables getting progressively worse in these 4 groups. A cutoff point of 2 core symptoms identified all but 3 patients with major depression and an additional 5% of the entire sample without major depression who were significantly (P<.05) worse than patients without depression on each of the validation variables. CONCLUSION: A strategy that includes the use of a 2-item depression screener followed by the evaluation of 4 core depressive symptoms is an efficient and effective way of identifying and classifying primary care patients with depression in need of clinical attention.