Thermodynamic analysis of Fe contamination in Cu-Mo alloys processed by mechanical alloying

ABSTRACT

This work aims to verify if Fe atoms coming from balls and jars enter into solid solution of Cu-Mo powders during mechanical alloying. The powders were milled and its structure and composition were characterised by scanning and transmission electron microscopy, and X-ray diffraction. Gibbs free of mixing values for Cu-Mo-Fe system were calculated using the Miedema’s model and showed that Cu-rich corner exhibit smallest energy values (<10?kJ?mol^?1). The observed coherency relation Cu(111) || Mo(101) || Fe(101) confirmed formation of solid solution. Fe atoms have entered in solid solution with Cu and Mo and do not remain as particles of second phase.     

The Religious Psychology of Mestizaje: Gómez Suárez de Figueroa or Garcilaso Inca de la Vega

Contrary to airtight notions of identity, this article argues that the construction of identity of peoples is far more complex and cannot be conceived separately from the sociocultural, religious and psychological dimensions of life. Using the example of the 16th century Peruvian writer Garcilaso de la Vega, I highlight the way in which the adoption of Catholic Christianity helped him resolve his internal psychological and existential identity conflict. By redefining the label of mestizaje and mestizo de la Vega reclaimed his dual ethnocultural identity, and began the painstaking job of carving a social space for people of mixed descent. He provides an alternative for framing the complex process of identity construction, and the central role of religion in it.     

Effects of different practice conditions on acquisition, retention, and transfer of soccer skills by 9-year-old schoolchildren

This study was designed to examine effects of three practice models, blocked, variable, and combined, on the acquisition, retention, and transfer of new motor skills. 67 subjects (M age = 9.5 yr., SD = .3) from the fourth year of primary school (31 boys and 26 girls) were assigned at random to three different practice groups (Blocked = 22, Variable = 23, Combined = 22) to study acquisition of two skills, dribbling a soccer ball and kicking a soccer ball at a stationary target using the dominant foot. All participants received a pretest and posttest, a transfer test, and a retention test 2 wk. later. Analysis showed significant improvement after practice of kicking skills by the three groups but not in the dribbling skills, for which only the combined practice group showed any notable improvement. At the end of acquisition, the combined practice group had significantly better performance on the dribbling task than the other two groups. However, the only differences noted in performance of kicking the ball with the dominant foot were by combined practice and blocked groups.     

Acquisition and retention in compound matching with hue and peck number elements

Pigeons learned and retained compound samples composed of hue (red vs. green) and peck number value [fixed-ratio (FR) 5 vs. FR 20] in a modified matching-to-sample (MTS) task. For different groups both FR and hue were relevant, or hue alone or FR value alone were relevant. Both acquisition and short-term retention of the samples were assessed. The rate of acquisition differed among the groups, with hue/FR > hue > FR. For groups hue/FR and hue, sample FR influenced the rate of learning, with larger sample FRs promoting faster learning. Sample FR also influenced working memory. When both hue and sample FR were relevant, and when FR alone was relevant, pigeons displayed better retention of the smaller (FR 5) sample—the “choose-small” effect. This dissociation of sample FR effects during acquisition and retention could be taken to indicate differences in the sources of immediate and delayed stimulus control.     

Effective behaviors to de-escalate organizational conflicts in the process of escalation

The goal of the present study was to determine what behaviors negotiators can use to help to quell an escalating conflict. In doing so, we formed a sample of professionals who took on the role of negotiator when we provoked an organizational conflict between a superior and subordinate that escalates due to the intervention of research confederates. Trained judges analyzed the negotiators' behaviors that most effectively mitigated the intensity of the conflict in which they were involved. The results demonstrate that the behaviors most effective at de-escalating an escalating conflict are problem-solving and accommodation, especially when said conflict has escalated considerably. Similarly, jointly employing problem-solving and direct fighting behaviors also seems to help de-escalate conflict. The results do not, however, consistently support using a forceful behavioral strategy to de-escalate a conflict in the early stages of escalation.     

2001 INVITED ADDRESS: Empowerment Evaluation: Building Communities of Practice and a Culture of Learning

Empowerment evaluation is the use of evaluation concepts, techniques, and findings to foster improvement and self-determination. Program participants—including clients—conduct their own evaluations: an outside evaluator often serves as a coach or additional facilitator depending on internal program capabilities. Empowerment evaluation has three steps: 1) establishing a mission; 2) taking stock; and 3) planning for the future. These three steps build capacity. They also build a sense of community, often referred to as communities of practice. Empowerment evaluation also helps to create a culture of learning and evaluation within an organization or community.     

Implicit alcohol and smoking associations among young adult heavy drinkers: Associations with smoking status and alcohol-cigarette co-use

Implicit memory associations may play a role in motivation to use alcohol and cigarettes, but the relationship between implicit associations and co-use of alcohol and cigarettes is currently unknown. This study provided an initial examination of alcohol and smoking implicit associations among young adult drinkers who were either nonsmokers or relatively light smokers (i.e., 10 or fewer cigarettes per day) as a function of smoking frequency and daily-level alcohol-cigarette co-use. Drinkers (n?=?129) completed alcohol-arousal and smoking-valence variants of the implicit association test as well as a daily-level assessment of past 90-day alcohol and cigarette use. Smokers were grouped according to whether they reported daily or nondaily smoking frequency. Results showed that although implicit alcohol-arousal associations did not differ between smokers and nonsmokers, stronger implicit alcohol-arousal associations were observed for nondaily smokers relative to daily smokers after controlling for drinking frequency. Further, implicit positive-smoking associations were stronger for smokers relative to nonsmokers. Within the subgroup of nondaily smokers, more frequent co-use of alcohol and cigarettes was associated with stronger implicit positive-smoking associations when controlling for total drinking and smoking frequency. The findings suggest that implicit alcohol and smoking associations may be linked with smoking patterns (daily vs. nondaily) and co-use of alcohol and cigarettes among young adult drinkers who are not heavy smokers, highlighting the need for more research on the role of implicit associations in the co-use of cigarettes and alcohol.     

On the role of hippocampal protein synthesis in the consolidation and reconsolidation of object recognition memory

Upon retrieval, consolidated memories are again rendered vulnerable to the action of metabolic blockers, notably protein synthesis inhibitors. This has led to the hypothesis that memories are reconsolidated at the time of retrieval, and that this depends on protein synthesis. Ample evidence indicates that the hippocampus plays a key role both in the consolidation and reconsolidation of different memories. Despite this fact, at present there are no studies about the consequences of hippocampal protein synthesis inhibition in the storage and post-retrieval persistence of object recognition memory. Here we report that infusion of the protein synthesis inhibitor anisomycin in the dorsal CA1 region immediately or 180 min but not 360 min after training impairs consolidation of long-term object recognition memory without affecting short-term memory, exploratory behavior, anxiety state, or hippocampal functionality. When given into CA1 after memory reactivation in the presence of familiar objects, ANI did not affect further retention. However, when administered into CA1 immediately after exposing animals to a novel and a familiar object, ANI impaired memory of both of them. The amnesic effect of ANI was long-lasting, did not happen after exposure to two novel objects, following exploration of the context alone, or in the absence of specific stimuli, suggesting that it was not reversible but was contingent on the reactivation of the consolidated trace in the presence of a salient, behaviorally relevant novel cue. Our results indicate that hippocampal protein synthesis is required during a limited post-training time window for consolidation of object recognition memory and show that the hippocampus is engaged during reconsolidation of this type of memory, maybe accruing new information into the original trace.     

The amygdala is involved in the modulation of long-term memory, but not in working or short-term memory

Rats with cannulae implanted in the junction between the central and the basolateral nuclei of the amygdala were trained in one-trial step-down inhibitory avoidance and tested at 3 s for working memory (WM) or 1.5 or 24 h later for short-term memory (STM) and long-term memory (LTM), respectively. Several drugs were infused 6 min prior to training in the animals in which WM was measured or 0 min posttraining in those in which STM and LTM were measured: the glutamate receptor antagonists CNQX (0.5 microg) and AP5 (5.0 microg), the indirect GABA A receptor antagonist picrotoxin (0.08 microg), the cholinergic muscarinic receptor blocker scopolamine (2. 0 microg), norepinephrine (0.3 microg), the protein kinase C inhibitor staurosporin (1.0 microg), or the calcium/calmodulin dependent protein kinase II inhibitor Kn-62 (3.5 ng). None of the drugs had any effect on either WM or STM. All had, as previously shown, strong effects on LTM: picrotoxin and norepinephrine enhanced it, and CNQX, AP5, scopolamine, Kn-62, and staurosporin inhibited it. The results do not support the idea that memory of this task is formed in the amygdala; they indicate that the amygdala is not involved in WM or STM processing and support the idea that the amygdala modulates LTM storage processes carried out elsewhere.