Scaffolding in Second Language Learning and Instruction

In a study of the triadic interaction among pairs of advanced second language learners engaged in a complex language task, it was found that the scaffolding provided by the researcher was determinant in keeping the participants on task and encouraging language production, thus facilitating both language development and comprehension.

Association of SNPs on CAPN1 and CAST genes with tenderness in Nellore cattle

We examined whether single-nucleotide polymorphisms (SNPs) in the calpain (CAPN) and calpastatin (CAST) genes, described from Bos primigenius taurus, are polymorphic in Nellore cattle. We also looked for a possible association of linkage disequilibrium of this polymorphism with tenderness of the longissimus dorsi muscle after 7, 14 and 21 days of postmortem aging in 638 purebred Nellore bulls. Meat tenderness was measured as Warner-Bratzler shear force. Additive and dominance effects were tested for SNPs of the three genotypic classes; the substitution effect was tested for SNPs with missing genotypic classes. Genotypic and gene frequencies were also calculated for the different SNPs. An increase in tenderness was observed from 7 to 21 days; the average values for shear force at 7, 14 and 21 days of aging were 5.92 +/- 0.06, 4.92 +/- 0.05, and 4.38 +/- 0.04 kg, respectively. All markers showed polymorphism, but there was no CC genotype for CAPN316, and few animals showed the AA genotype for CAPN530. The alleles CAPN4751, UOGCAST1, and WSUCAST were found to have additive and dominance effects for shear force at 7, 14 and 21 days, while CAPN316 showed a substitution effect for shear force at 7 and 21 days. An additive-by-additive epistatic interaction was observed between CAPN4751 and markers on the CAST gene. In conclusion, these markers should be considered for use in breeding programs.

Modulation of Mediotemporal and Ventrostriatal Function in Humans by Delta 9-Tetrahydrocannabinol A Neural Basis for the Effects of Cannabis sativa on Learning and Psychosis

Context: Cannabis sativa use can impair verbal learning, provoke acute psychosis, and increase the risk of schizophrenia. It is unclear where C sativa acts in the human brain to modulate verbal learning and to induce psychotic symptoms. Objectives: To investigate the effects of 2 main psychoactive constituents of C sativa, Delta 9-tetrahydrocannabinol (Delta 9-THC) and cannabidiol, on regional brain function during verbal paired associate learning. Design: Subjects were studied on 3 separate occasions using a block design functional magnetic resonance imaging paradigm while performing a verbal paired associate learning task. Each imaging session was preceded by the ingestion of Delta 9-THC (10 mg), cannabidiol (600 mg), or placebo in a double-blind, randomized, placebo-controlled, repeated-measures, within-subject design. Setting: University research center. Participants: Fifteen healthy, native English-speaking, right-handed men of white race/ethnicity who had used C sativa 15 times or less and had minimal exposure to other illicit drugs in their lifetime. Main Outcome Measures: Regional brain activation ( blood oxygen level-dependent response), performance in a verbal learning task, and objective and subjective ratings of psychotic symptoms, anxiety, intoxication, and sedation. Results: Delta 9-Tetrahydrocannabinol increased psychotic symptoms and levels of anxiety, intoxication, and sedation, whereas no significant effect was noted on these parameters following administration of cannabidiol. Performance in the verbal learning task was not significantly modulated by either drug. Administration of Delta 9-THC augmented activation in the parahippocampal gyrus during blocks 2 and 3 such that the normal linear decrement in activation across repeated encoding blocks was no longer evident. Delta 9-Tetrahydrocannabinol also attenuated the normal time-dependent change in ventrostriatal activation during retrieval of word pairs, which was directly correlated with concurrently induced psychotic symptoms. In contrast, administration of cannabidiol had no such effect. Conclusion: The modulation of mediotemporal and ventrostriatal function by Delta 9-THC may underlie the effects of C sativa on verbal learning and psychotic symptoms, respectively.

European Schools Survey Project on Alcohol and other drugs (ESPAD)

ESPAD is a collaborative effort of independent research teams in about forty European countries and the largest cross-national research project on adolescent substance use in the world. Data are collected every fourth year with 1995 as the starting point. The fourth data collection was carried out in 35 countries during the spring of 2007 and the results were published March 26, 2009 The overall purpose of the ESPAD project is to study adolescent substance use in Europe from a comparative and longitudinal perspective. The basic goal is to collect comparable data on the use of alcohol, tobacco and other drugs among students throughout European countries. Data should be collected in cooperation between countries using a strictly standardised methodology, in order to offer as comparable results as possible. In the long run the most important aim is to monitor the of trends of the adolescent substance use in European countries and to compare trends between countries. This includes the mapping of differences and the monitoring of trends for policy purposes as well as the scientific study of the context, predictors and consequences of adolescent substance use. In relation to the EU action plan on drugs and the WHO Europe declaration about young people and alcohol, ESPAD-data can provide information for the evaluation of these charters. It is intended to repeat the surveys every fourth year. All European countries are welcome to join the ESPAD study, in the effort of making the coverage across Europe as complete as possible. Click here to download PDF 2.1mb

Effects of caffeine on learning and memory in rats tested in the Morris water maze

We studied some of the characteristics of the improving effect of the non-specific adenosine receptor antagonist, caffeine, using an animal model of learning and memory. Groups of 12 adult male Wistar rats receiving caffeine (0.3-30 mg/kg, ip, in 0.1 ml/100 g body weight) administered 30 min before training, immediately after training, or 30 min before the test session were tested in the spatial version of the Morris water maze task. Post-training administration of caffeine improved memory retention at the doses of 0.3-10 mg/kg (the rats swam up to 600 cm less to find the platform in the test session, P<=0.05) but not at the dose of 30 mg/kg. Pre-test caffeine administration also caused a small increase in memory retrieval (the escape path of the rats was up to 500 cm shorter, P<=0.05). In contrast, pre-training caffeine administration did not alter the performance of the animals either in the training or in the test session. These data provide evidence that caffeine improves memory retention but not memory acquisition, explaining some discrepancies among reports in the literature.

Disambiguating the Effects of Social Instability Stress in Adolescence on Learning and Memory Tasks that Involve the Medial Prefrontal Cortex and Hippocampus

Exposure to chronic stress can alter the structure and function of brain regions involved in learning and memory, and these effects are typically long-lasting if the stress occurs during sensitive periods of development. Until recently, adolescence has received relatively little attention as a sensitive period of development, despite marked changes in behaviour, heightened reactivity to stressors, and cognitive and neural maturation. Therefore, the purpose of the present study was to investigate the long-term effects of chronic stress in adolescence on two spatial learning and memory tasks (Morris water maze and Spatial Object Location test) and on a working memory task (Delayed Alternation task). Male rats were randomly assigned to chronic social instability stress (SS; daily 1 hour isolation and subsequent change of cage partner between postnatal days 30 and 45) or to a no-stress control group (CTL). During acquisition learning in the Morris water maze task, SS rats demonstrated impaired long-term memory for the location of the hidden escape platform compared to CTL rats, although the impairment was only seen after the first day of training. Similarly, SS rats had impaired long-term memory in the Spatial Object Location test after a long delay (240 minutes), but not after shorter delays (15 or 60 minutes) compared to CTL rats. On the Delayed Alternation task, which assessed working memory across delays ranging from 5 to 90 seconds, no group differences were observed. These results are partially in line with previous research that revealed adult impairment on spatial learning and memory tasks after exposure to chronic social instability stress in adolescence. The observed deficits, however, appear to be limited to long-term memory as no group differences were observed during brief periods of retention.

A resumé of selected research on superior and talented high school students.

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Effect of the Florida A+ Plan on curriculum and instruction in Title I public elementary schools

The purpose of this research was to study the effect of the Florida A+ Plan accountability program on curriculum and instruction in four Title I public elementary schools in the Miami-Dade County Public Schools system. It focused on the experiences of the school principals and the classroom teachers of the four schools as they related to curriculum and instruction. The study included an analysis of the school improvement plans in curriculum and instruction for each school during the school years 1998-2004. ^ The study was conducted in the format of interviews with the school principals and principal selected classroom teachers who taught third, fourth, or fifth grade during the first six years of the Florida A+ Plan. The analysis of the school improvement plans focused on the implementation of curriculum and instruction for each of the four schools. It focused on the goals and measurable objectives selected by each school to improve its instructional program in the academic subjects of reading, mathematics, writing, and science. ^ The findings indicated that under the pressure to improve their school grade on the Florida A+ Plan, each of the target schools, based on individual needs assessments, and restructured their instructional program each school year as documented in their school improvement plans. They altered their programs by analyzing student performance data to realign curriculum and instruction. The analysis of the interviews with the principals and the teachers showed that each school year they restructured their program to align it with the FCAT content. This realigning was a collaborative effort on the part of the administration and the instructional staff. ^

Commentary on: Are we overpathologizing everyday life? A tenable blueprint for behavioral addiction research: On functional and compulsive aspects of reinforcement pathologies

Background: This paper is a commentary to a debate article entitled: "Are we overpathologizing everyday life? A tenable blueprint for behavioral addiction research", by Billieux et al. (2015). Methods and aim: This brief response focused on the necessity to better characterize psychological and related neurocognitive determinants of persistent deleterious actions associated or not with substance utilization. Results: A majority of addicted people could be driven by psychological functional reasons to keep using drugs, gambling or buying despite the growing number of related negative consequences. In addition, a non-negligible proportion of them would need assistance to restore profound disturbances in basic learning processes involved in compulsive actions. Conclusions: The distinction between psychological functionality and compulsive aspects of addictive behaviors should represent a big step towards more efficient treatments.

Effects of postnatal protein malnutrition on learning and memory procedures

Protein malnutrition induces structural, neurochemical and functional changes in the central nervous system leading to alterations in cognitive and behavioral development of rats. The aim of this work was to investigate the effects of postnatal protein malnutrition on learning and memory tasks. Previously malnourished (6% protein) and well-nourished rats (16% protein) were tested in three experiments: working memory tasks in the Morris water maze (Experiment I), recognition memory of objects (Experiment II), and working memory in the water T-maze (Experiment III). The results showed higher escape latencies in malnourished animals in Experiment I, lower recognition indexes of malnourished animals in Experiment II, and no differences due to diet in Experiment III. It is suggested that protein malnutrition imposed on early life of rats can produce impairments on both working memory in the Morris maze and recognition memory in the open field tests.