How does the heel-off posture modify gait initiation parameter programming?

The authors studied the adjustment of the 2 distinct known expressions of gait velocity, the velocity of the center of gravity (CG) and the velocity of the center of foot pressure (CP) at the end of the 1st step in 2 experimental situations: natural gait initiation (the control situation, CS) and heel-off gait initiation (the test situation, TS). Gait was initiated by 7 healthy participants, from an erect spontaneous posture in the CS and from a posture with heels raised in the TS, on a force platform at 3 self-selected speed conditions. Biomechanical data from the force platform were collected in both experimental situations, and the authors used a particular gait analysis based on the differential method of Y. Brenière (2003) in order to approach velocity modulation by means of step length and frequency. Results showed that CG and CP velocities were adjusted differently during heel-off gait initiation than during natural gait initiation. CP velocity, as compared with CG velocity, was overestimated in TS. Results also established the relevance of the expression of step velocity by means of step length and frequency: The central nervous system, taking into account the specific postural constraints of each experimental situation, uses a reference value and a regulating parameter to modulate step velocity. Moreover, the contributions of 1st step length and frequency to the expression of step velocity in TS and CS were different. Thus, a specific locomotor behavior corresponds to a given experimental situation that is characterized by its own initial biomechanical constraints.     

Stimulation of hippocampal adenylyl cyclase activity dissociates memory consolidation processes for response and place learning

Procedural and declarative memory systems are postulated to interact in either a synergistic or a competitive manner, and memory consolidation appears to be a highly critical stage for this process. However, the precise cellular mechanisms subserving these interactions remain unknown. To investigate this issue, 24-h retention performances were examined in mice given post-training intrahippocampal injections of forskolin (FK) aiming at stimulating hippocampal adenylyl cyclases (ACs). The injection was given at different time points over a period of 9 h following acquisition in either an appetitive bar-pressing task or water-maze tasks challenging respectively "response memory" and "place memory." Retention testing (24 h) showed that FK injection altered memory formation only when given within a 3- to 6-h time window after acquisition but yielded opposite memory effects as a function of task demands. Retention of the spatial task was impaired, whereas retention of both the cued-response in the water maze and the rewarded bar-press response were improved. Intrahippocampal injections of FK produced an increase in pCREB immunoreactivity, which was strictly limited to the hippocampus and lasted less than 2 h, suggesting that early effects (0-2 h) of FK-induced cAMP/CREB activation can be distinguished from late effects (3-6 h). These results delineate a consolidation period during which specific cAMP levels in the hippocampus play a crucial role in enhancing memory processes mediated by other brain regions (e.g., dorsal or ventral striatum) while eliminating interference by the formation of hippocampus-dependent memory.     

Teaching Strategies and Adaptations of Teachers in Multiculturally Diverse Classrooms in Seventh-day Adventist K-8 Schools in North America

The purpose of this study was to describe the experiences of Adventist teachers—their training, their use of instructional strategies, and the challenges they encounter when teaching students of different cultures. Banks' multicultural paradigms was the theoretical framework from which a survey was developed and sent to all K-8 Adventist teachers in the United States and Canada. Strategies relating to the self-concept development and ethnic additive paradigms were used most frequently by Adventist teachers while those associated with the language paradigm were used the least. Almost half of the teachers subscribed to the goal that “students are individuals with distinct personalities regardless of their background” while about 10% of the teachers considered the goals relating to “protection of diverse groups” the most important. Their strategy use was not related to their most important goals (Nels) for multicultural education. Forty percent of the teachers had no training in multicultural education and the study recommends training so that Adventist teachers will have more effective strategies for relating to diverse students.     

Acceptance,well-being and goals in adolescents with chronic illness: a daily process analysis

Objective: The main aim of this study was to investigate the relationship between acceptance and well-being in adolescents with chronic illness from a daily process perspective. Furthermore, we explored the role of daily experienced interference and facilitation of life goals by treatment goals as mediating mechanisms.

Methods: Thirty-eight adolescents with cystic fibrosis (CF) or diabetes completed questionnaires assessing acceptance, negative life events and goal-related self-efficacy. Furthermore, an online diary assessing daily mood, daily experienced interference and facilitation of life goals by treatment goals was completed during three consecutive weeks.

Results: Acceptance of illness was positively related to daily well-being, but unrelated to daily goal interference and facilitation. Furthermore, daily goal interference and facilitation were unrelated to same-day and next-day well-being.

Conclusion: This study suggests that acceptance of illness plays an important role in the daily mood of adolescents with CF and diabetes. This relationship, however, was not mediated by daily experienced interference and facilitation of life goals by treatment goals. Further research is needed to determine whether interventions promoting acceptance are beneficial for adolescents with CF and diabetes.     

Under Pressure: The Effects of Stress on Positive and Negative Relationship Behaviors

This study investigates the effects of acute stress on positive and negative relationship behaviors, specifically assurances and attention to alternatives. A sample of 129 college students were randomly assigned to either a high or low stress condition, then were led to believe they had the opportunity to interact with attractive potential relationship partners and list compliments about their current partner. Results indicated that those in the high stress condition gave their partner fewer assurances and paid more attention to alternatives. These results suggest that when individuals experience acute stress, they may engage in fewer positive relationship behaviors and more behaviors that are potentially harmful to their relationship.     

The emergence of explicit knowledge from implicit learning

Substantial evidence has highlighted the ability of observers to incidentally extract statistical contingencies present in visual environments. This study examined whether the knowledge extracted regarding statistical contingencies is unconscious initially, even when it becomes fully accessible to conscious awareness after extensive training. Using a “typical” contextual cuing procedure adapted to real-world scenes, we first observed that, after extensive training in searching for a target within repeated scenes, knowledge about regularities was associated with conscious awareness (Experiment 1). However, both subjective and objective measures of consciousness revealed that in the early phase of training, learning of regular structures first takes place at an unconscious level (Experiments 2 and 3). These results are discussed in the light of the causal relationships between learning and consciousness.     

How visual and semantic information influence learning in familiar contexts

Previous research using the contextual cuing paradigm has revealed both quantitative and qualitative differences in learning depending on whether repeated contexts are defined by letter arrays or real-world scenes. To clarify the relative contributions of visual features and semantic information likely to account for such differences, the typical contextual cuing procedure was adapted to use meaningless but nevertheless visually complex images. The data in reaction time and in eye movements show that, like scenes, such repeated contexts can trigger large, stable, and explicit cuing effects, and that those effects result from facilitated attentional guidance. Like simpler stimulus arrays, however, those effects were impaired by a sudden change of a repeating image's color scheme at the end of the learning phase (Experiment 1), or when the repeated images were presented in a different and unique color scheme across each presentation (Experiment 2). In both cases, search was driven by explicit memory. Collectively, these results suggest that semantic information is not required for conscious awareness of context-target covariation, but it plays a primary role in overcoming variability in specific features within familiar displays. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Democracy,Epistemology and the Problem of All‐White Juries

Does it matter that almost all juries in England and Wales are all‐White? Does it matter even if this result is the unintended and undesired result of otherwise acceptable ways of choosing juries? Finally, does it matter that almost all juries are all‐White if this has no adverse effect on the treatment of non‐White defendants and victims of crime? According to Cheryl Thomas, there is no injustice in a system of jury selection which predictably results in juries with no minority members so long as this result is not deliberate, and does not adversely affect the treatment of minority defendants and victims of crime. My view is different. In and of itself, I believe, something is wrong with a system of jury selection that predictably results in all‐White juries in a diverse society, such as our own. Absent reason to believe that we lack a better alternative to current modes of jury selection, a commitment to democratic government and to the equality of citizens – or so I will argue – condemns existing arrangements as unjust, whether or not they have adverse effects on jury decisions, or on the ways in which our society approaches issues of race and crime.