Distinguishing social and asocial learning using diffusion dynamics

Theoretical models predict that the cumulative number of individuals displaying a socially learned novel behavior will follow an accelerating pattern over time, whereas asocial processes have been associated with linear or decelerating functions. This raises the possibility that the shape of the diffusion curve may reveal something about the learning processes involved. If true, this would be particularly useful for identifying social transmission in observational field studies. Published data are reviewed and are found to provide limited support for this view. The use of accelerating curves as a diagnostic is challenging because (1) alternative theoretical models make similar predictions, (2) clear supporting empirical data are lacking, and (3) practical considerations frequently make accurate construction of the diffusion curve difficult.     

Effect of tramadol on immune responses and nociceptive thresholds in a rat model of incisional pain

Objective: To evaluate the effects oftramadol on the proinflammatory responses in a rat model of incisional pain by investigating its effects on nociceptive thresholds and serum interleukin-6 (IL-6) and IL-2 levels. Methods: Forty-two male Sprague-Dawley (SD) rats scheduled for plantar incision were randomly divided into 7 groups (n=6 in each group). Rats in Group 1 receiving general anesthesia with no incision were served as control; At 30 min before skin incision, Groups 2～5 were given 5 ml normal saline or 1, 10, and 20 mg/kg tramadol, respectively, intraperitoneally (i.p.); Group 6 received 10 mg/kg tramadol after operation; Group 7 received 10 mg/kg tramadol before incision, followed by 200 μg/kg naloxone after operation. Mechanical allodynia was measured by electronic von Frey filament to evaluate the nociceptive thresholds 1 h before incision, and 1 h and 2 h after operation. Serum IL-6 and IL-2 levels were measured by enzyme-linked immunosorbent assay (ELISA) 2 h after operation. Results: Mechanical thresholds decreased significantly and serum IL-6 level increased significantly after operation in Group 2 compared with control (P＜0.01), and these changes were reversed respectively by tramadol in a dose-dependent manner (P＜0.05 and P＜0.01, respectively). IL-2 level remained unchanged after operation in Group 2, but decreased in Group 3 (P＜0.05), then gradually returned to the normal level in Groups 4 and 5. The intraperitoneally injected tramadol (10 and 20 mg/kg) produced a potent and dose-dependent antinocicptive effect on the lesioned paw. The antinocicptive effects of tramadol were partially an-tagonized by naloxone (200 μg/kg), suggesting an additional non-opioid mechanism. Conclusion: The results suggest that tramadol could be a good choice for the treatment of pain under the conditions that immunosuppression may be particularly contraindicated.     

SAFE Homes: is it worth the cost? An evaluation of a group home permanency planning program for children who first enter out-of-home care

OBJECTIVE: To evaluate the SAFE Homes (SH) program, a short-term group care program for children between 3 and 12 years of age who enter care for the first time. The program aims to improve case outcomes by consolidating resources to facilitate assessment and treatment planning. METHODS: The 1-year outcomes of 342 children who received SAFE Home services and 342 matched foster care (FC) control children were compared. The 684 subjects used in this report were selected from a larger pool of 909 subjects using propensity score matching to control for hidden bias in treatment group assignment. We hypothesized that SAFE Homes would result in greater continuity of care for children (e.g., fewer placements, more placements with siblings and in towns of origin), identification of more relatives for substitute care when needed, reduced use of high-cost restrictive care settings (e.g., residential, inpatient), and reduced rates of re-abuse through earlier detection and provision of services to meet child and family treatment needs. RESULTS: Prior to the initiation of the SAFE Homes program, 75% of the children who entered care in the State experienced three or more placements in the first year. The outcomes of both the SH and FC cases were significantly improved over pre-SAFE Home State statistics. The FC group, however, had comparable or better outcomes on most variables examined. In addition, the total cost for out-of-home care for the children in FC was significantly less, despite the fact that the two groups spent similar amounts of time in care (average time in care: 7 months). This finding held when the total placement cost was calculated using the State reimbursement rate of 206.00 US dollars per day for SAFE Home care (SH: 20,851 US dollars +/- 24,231 US dollars; FC: 8,441 US dollars +/- 21,126 US dollars, p < .001), and a conservative SAFE Home program fee of 85.00 US dollars per day that only considered the child care and custodial staffing costs uniquely associated with the program (SH: 13,314 US dollars +/- 21,718 US dollars; FC: 8,441 US dollars +/-21,126 US dollars, p < .001). CONCLUSION: Improvements in outcomes related to continuity of care can be attained through staff training. The SAFE Home model of care is not cost-effective for first-time placements.     

Fluid and electrolyte balance in elite male football (soccer) players training in a cool environment

There are few data in the published literature on sweat loss and drinking behaviour in athletes training in a cool environment. Sweat loss and fluid intake were measured in 17 first-team members of an elite soccer team training for 90 min in a cool (5 degrees C, 81% relative humidity) environment. Sweat loss was assessed from the change in body mass after correction for the volume of fluid consumed. Sweat electrolyte content was measured from absorbent patches applied at four skin sites. Mean (+/- s) sweat loss during training was 1.69+/-0.45 l (range 1.06-2.65 l). Mean fluid intake during training was 423+/-215 ml (44-951 ml). There was no apparent relationship between the amount of sweat lost and the volume of fluid consumed during training (r2 = 0.013, P = 0.665). Mean sweat sodium concentration was 42.5+/-13.0 mmol l(-1) and mean sweat potassium concentration was 4.2+/-1.0 mmol x l(-1). Total salt (NaCl) loss during training was 4.3+/-1.8 g. The sweat loss data are similar to those recorded in elite players undergoing a similar training session in warm environments, but the volume of fluid ingested is less.     

Mother-child conversational interactions as events unfold: linkages to subsequent remembering

The study reported here was designed to examine linkages between mother-child conversational interactions during events and children's subsequent recall of these activities. In this longitudinal investigation, 21 mother-child dyads were observed while they engaged in specially constructed activities when the children were 30, 36, and 42 months of age. Analyses of the children's 1-day and 3-week recall of these events indicated that at all age points, features of the activities that were jointly handled and jointly discussed by the mother and child were better remembered than were features that were either (1) jointly handled and talked about only by the mother, or (2) jointly handled and not discussed. Potential linkages were also explored between incidental memory for personal experiences and deliberate recall of familiar but arbitrary materials. In this regard, children's recall of the special activities was positively correlated with their recall of objects in a deliberate memory task performed at 42 months.     

Developmental and individual differences in girls' sex-typed activities in middle childhood and adolescence

Girls' time in sex-typed leisure activities was studied across 2 years in middle childhood ( n =98, M =8.2 years in Year 1), early adolescence ( n =106, M =11.7 years), and middle adolescence ( n =86, M =14.9 years). In annual home interviews, White middle-class girls, mothers, and fathers rated their gendered attitudes, interests, and personality qualities, and saliva samples were used to assess testosterone; activity data were collected in 7 nightly phone interviews. Girls spent more time in feminine than masculine activities except in early adolescence. Girls' and parents' personalities and interests predicted sex-typed activities at each developmental period, but associations between testosterone and activities emerged only in middle childhood.     

Mexican-Origin Youth's Cultural Orientations and Adjustment: Changes From Early to Late Adolescence

Drawing from developmental and cultural adaptation perspectives and using a longitudinal design, this study examined: (a) mean‐level changes in Mexican‐origin adolescents’ cultural orientations and adjustment from early to late adolescence and (b) bidirectional associations between cultural orientations and adjustment using a cross‐lag panel model. Participants included 246 Mexican‐origin, predominantly immigrant families that participated in home interviews and a series of nightly phone calls when target adolescents were 12 and 18 years of age. Girls exhibited more pronounced declines in traditional gender role attitudes than did boys, and all youth declined in familism values, time spent with family, and involvement in Mexican culture. Bidirectional relations between cultural orientations and adjustment emerged, and some associations were moderated by adolescent nativity and gender.     

The birth of words: ten-month-olds learn words through perceptual salience

A core task in language acquisition is mapping words onto objects, actions, and events. Two studies investigated how children learn to map novel labels onto novel objects. Study 1 investigated whether 10-month-olds use both perceptual and social cues to learn a word. Study 2, a control study, tested whether infants paired the label with a particular spatial location rather than to an object. Results show that 10-month-olds can learn new labels and do so by relying on the perceptual salience of an object instead of social cues provided by a speaker. This is in direct contrast to the way in which older children (12-, 18-, and 24-month-olds) learn and extend new object names.     

Race, ethnicity, and culture in child development: contemporary research and future directions

The editors of this special issue reflect on the current status and future directions of research on race, ethnicity, and culture in child development. Research in the special issue disentangles race, ethnicity, culture, and immigrant status, and identifies mediators of sociocultural variables on developmental outcomes. The special issue includes important research on normal development in context for ethnic and racial minority children, addresses racial and ethnic identity development, and considers intergroup processes. The methodological innovations as well as challenges of current research are highlighted. It is recommended that future research adhere to principles of cultural validity described in the text.