Internet use in the contemporary media environment

Although a significant amount of research has focused on traditional media choice and use, and even on some ‘new’ media, these studies have either neglected the Internet and World Wide Web or were conducted prior to their recent popularity. This study offers a novel exploration of individuals' use of three Internet functions (information retrieval, information giving, and conversation capabilities) in the context of the use of other communication media. Data from 684 individuals demonstrate that the Internet is a multidimensional technology used in a manner similar to other, more traditional media. Specifically, conversation features of the Internet align with mediated interpersonal technologies (the telephone and electronic mail), whereas the Internet's information‐retrieval and information‐giving features are used in ways similar to mass media channels (newspapers, television, and books and magazines). In addition, needs fulfilled by these channels cluster in ways consistent with past research, regardless of the technologies employed to meet them.     

In Vivo Hippocampal Acetylcholine Release During Exposure to Acute Stress

Hippocampal extracellular acetylcholine (ACh) and choline levels were evaluated using in vivo microdialysis in male Fischer 344 rats before, during, and following an 80-min exposure to two different stress conditions. Measurements were taken in rats restrained and immersed in a water bath containing either 37 degreesC (normothermic-restraint) or 20 degreesC (cold-restraint) water. Results were compared to normothermic-freely-moving rats. Cold-restrained rats displayed decreased ACh levels during cold exposure relative to both normothermic-restrained and normothermic-freely-moving rats. By the end of the cold exposure period and following removal from cold, ACh levels had returned to near-baseline values. Normothermic-restrained rats had levels similar to those of normothermic-freely-moving rats, except for a marked increase in ACh following removal from restraint. Cold-restrained rats displayed a gradual elevation in choline levels during cold stress, followed by a gradual decline after stress termination, whereas both normothermic-restrained and normothermic-freely-moving rats displayed gradual decreases during the microdialysis session. These findings demonstrate that central cholinergic neurotransmission can be altered by the application of, and removal from, acute stressors. In addition, the results suggest a possible relationship between the magnitudes of both the stressor and its cholinergic consequences.     

Factor structure of the Spanish adaptation of Tarrant's Group Identification Scale

In this study, the factor structure of the Spanish version of Tarrant's Group Identification Scale is analyzed. This scale is based on the social identity theory and measures cognitive, evaluative, and affective aspects of group identification. Although this scale has been considered unidimensionally with adolescents, it is based on previous group identification scales considered multidimensionally. From confirmatory analysis, some factor models were tested in two independent samples of adolescents: Spanish (N= 1,795) and Mexican (N= 1,494). The three-factor model (self-categorization, group evaluation, and commitment to the group) produced the best fit in both samples. Results are compatible with the multidimensional structure hypothesis of group identification.     

Clamped Corticosterone (B) Reveals the Effect of Endogenous B on Both Facilitated Responsivity to Acute Restraint and Metabolic Responses to Chronic Stress

To determine the effects of both corticosterone (B) and chronic stressors on acute ACTH responses to restraint, young male rats were exposed to streptozotocin-induced diabetes, cold (5-7 degreesC) or intracerebroventricular (icv) neuropeptide Y (NPY) for 5 d and then exposed to restraint within 2 h after lights on. Two groups of rats were studied: intact and adrenalectomized replaced with B pellets that maintained plasma B in the normal mean 24-h range of intact rats. In addition to ACTH and B responses to restraint on d 5, body weight, food intake, fat depots, glucose and other hormones were measured to determine the role of stress-induced elevations in B on energy balance. ACTH responses to restraint were normal in intact rats subjected to diabetes or cold. By contrast, there was no ACTH or B response to restraint in NPY-infused intact rats. All 3 groups of chronically stimulated adrenalectomized rats with clamped B had facilitated ACTH responses to restraint compared to their treatment controls. Overall food intake increased in all groups of stressed rats; however, augmented intake occurred only during the light in intact rats and equally in the light and dark in B-clamped rats. White adipose depot weights were decreased by both diabetes and cold and increased by NPY in intact rats; the decreases with cold and increases with NPY were both blunted and changes in fat stores were not significant in adrenalectomized, B-clamped rats. We conclude that: 1. diabetes- and cold-induced facilitation of restraint-induced afferent input to hypothalamic control of the hypothalamo-pituitary-adrenal (HPA) axis is opposed in intact rats by the elevated feedback signal of B secretion; 2. NPY does not induce facilitation of afferent stress pathways; 3. chronic stimulation of the HPA axis induces acute hyperresponsiveness of hypothalamic neurons to restraint provided that the afferent input of this acute stimulus is not prevented by B feedback; 4. stimulus-induced elevations in B secretion result in day-time feeding; 5. insensitivity of both caloric efficiency and white fat stores to chronic stress in adrenalectomized, B-clamped rats results from loss of normally variable B levels.     

Family and school violence: the mediator role of self-esteem and attitudes towards institutional authority

This study analyses the influence of family communication and parental valuation of school on adolescent violent behaviour at school. By means of a structural equation model, both its direct and indirect influence through school and family self-esteem of the adolescent and his attitude towards school authority are analysed. The sample is composed of 665 adolescents whose ages range from 12 to 16 years old. The results confirm the existence of an indirect relationship but not direct influence of the family on school violence. The attitude of the adolescent towards school authority is the mediator variable which shows the strongest direct effect on school violence. Also, the two dimensions of self-esteem considered are significant intermediate variables. These results and their implications are analysed.     

Intercultural Study of Personal Space: A Case Study

The study of intercultural differences in personal space attempts to identify factors that could be helpful in guiding people from different cultures to live and work together in international ventures. The objective of this research was to measure interpersonal distance in a cross-cultural environment. Twenty-three participants classified in 4 cultural groups answered an 11-questions interview where the personal distance and orientation between seated interactants were measured. Results showed that Anglo Saxons used the largest zone of personal space, followed by Asians, then Caucasians, and, as expected, Mediterraneans and Latinos used the shortest distance. Where Latinos adopt a face-to-face position, Caucasians tend to orient themselves to the side of the interviewer, which has an impact on interpersonal communication.     

Individual and social risk factors related to overt victimization in a sample of Spanish adolescents

This study analyzes the role of adolescents' self-esteem, loneliness, sociometric status, and perceptions of family and classroom environment on overt vicitimization by peers in a sample of 1319 Spanish adolescents (48% boys and 52% girls), ages 11 to 16 years (M=13.7, SD=1.5). The findings from structural equation modeling suggest that adolescents' self-esteem, loneliness, and sociometric status had a significant direct effect on overt victimization by peers, and adolescents' perceptions of family and classroom environment had a significant indirect effect on peer overt victimization mediated by self-esteem, loneliness, and sociometric status. The findings are discussed with the consideration of these variables as individual and social risk factors for overt victimization by peers.     

Differences in protective factors of substance use in early and middle adolescence

This study focuses on possible differences in protective factors of substance use in early and middle adolescence. These possible differences are analysed by means of the same structural equation model applied to two different samples of adolescents: the first sample is made up of 450 adolescents, ages 12 to 14 years, and second of 203 adolescents, ages 15 to 17 years. The results indicate that adequate family communication is a protective factor in both samples, whereas high social self-esteem is proposed as a risk factor in middle adolescence. The adolescent's family self-esteem and attitudes towards authority are also relevant factors in both samples. These results may have important implications in the development of future intervention programmes.     

Cyberbullying: adolescent victimization through mobile phone and internet

The aim of this study was to analyse the prevalence of victimization through mobile phone and internet. The differences of gender and academic year in the type of electronic aggression were also examined. The sample comprised 2001 adolescents of both genders and ages between 11 and 17 years. Results indicated that 24.6% of the adolescents had been bullied by mobile phone during the last year, and 29% through internet. In most of the electronic aggressions, girls were more bullied than boys. It was also observed that students attending the first two years of secondary education tended to be more victimized.