Developmental effects of acute, chronic, and withdrawal from chronic nicotine on fear conditioning

Pre-adolescence and adolescence are developmental periods associated with increased vulnerability for tobacco addiction, and exposure to tobacco during these periods may lead to long-lasting changes in behavioral and neuronal plasticity. The present study examined the short- and long-term effects of nicotine and nicotine withdrawal on fear conditioning in pre-adolescent, adolescent, and adult mice, and potential underlying substrates that may mediate the developmental effects of nicotine, such as changes in nicotinic acetylcholine receptor (nAChR) binding, CREB expression, and nicotine metabolism. Age-related differences existed in sensitivity to the effects of acute nicotine, chronic nicotine and nicotine withdrawal on contextual fear conditioning (no changes in cued fear conditioning were seen); younger mice were more sensitive to the acute effects and less sensitive to the effects of nicotine withdrawal 24 h post treatment cessation. Developmental differences in nAChR binding were associated with the effects of nicotine withdrawal on contextual learning. Developmental differences in nicotine metabolism and CREB expression were also observed, but were not related to the effects of nicotine withdrawal on contextual learning 24 h post treatment. Chronic nicotine exposure during pre-adolescence or adolescence, however, produced long-lasting impairments in contextual learning that were observed during adulthood, whereas adult chronic nicotine exposure did not. These developmental effects could be related to changes in CREB. Overall, there is a developmental shift in the effects of nicotine on hippocampus-dependent learning and developmental exposure to nicotine results in adult cognitive deficits; these changes in cognition may play an important role in the development and maintenance of nicotine addiction.     

A brief assessment tool for body image in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) may adversely affect body image in multitude ways. Development and validation of a brief and valid SLE specific body image tool were undertaken. Eleven items were identified on interview of 21 SLE patients for the Body Image Lupus Scale (BILS v1.0). The tool was administered to 70 SLE patients. Based on analysis, feedback, and refinement of items, the final iteration BILS v1.2 with five items was administered to 233 SLE patients along with validated body image measures (Situational Inventory of Body Image Dysphoria and Body Image Quality of Life Inventory) and health-related quality of life measures for a subsample. The BILS scores' had an internal consistency reliability of .94. It correlated with both the referent body image measures, and with health-related quality of life. It differentiated participants by health status and disease activity. Test-retest reliability estimates exceeded .90. These results support the psychometric properties of BILS.     

Challenges in Transforming Military Training: Research and Application of Advanced Simulation and Training Technologies and Methods

This study addresses the need to validate estimates of cross-job retraining times against measures of actual retraining success. Specialty-level cross-job retraining time estimates were computed for 43 U.S. Air Force (USAF) enlisted specialties. The estimates were based on profiles of mean subject- matter-expert ratings of months to proficiency across 26 task categories. Individual-level criteria indicating previous job skill utilization, current skills and abilities, and current job performance were obtained from a separate study conducted 10 years earlier. Results were supportive: Correlations between retraining time estimates and performance criteria were negative and statistically significant. Future research needs and potential applications of retraining time estimates are discussed.     

Measuring Team Performance in Complex and Dynamic Military Environments: The SPOTLITE Method

The Scenario-based Performance Observation Tool for Learning In Team Environments (SPOTLITE) provides a systematic method for developing team performance measurement instruments comprised of behaviorally anchored rating scales that are tied to observable behaviors that tap critical knowledge and skills and can be assessed at specific intervals during a training scenario. We developed a measurement instrument for four-person teams of F-16 pilots training for air-to-air combat in a high-fidelity simulation environment and implemented it in a handheld computer to support fast and accurate data entry as a team executes a scenario. An experiment demonstrated the sensitivity, reliability, and validity of the instrument.     

Influence of the restored work-hardening rate on ductility studied by X-ray computed tomography

Abstract

Void growth and coalescence in a model material containing an artificial three-dimensional void array (the estimated local void volume fraction was 1.1%) were investigated by X-ray computed tomography (=XCT). The initially tapered cylindrical voids became elongated along the principal straining direction by some amount of tensile plastic deformation, and then the work-hardening capacity in the intervoid matrix was restored by an intermediate annealing. The annealed model material was pulled in tension all the way up to fracture to see if the existing void coalescence models can predict the void coalescence strain.     

Differentiating core and co-opted mechanisms in calculation: The neuroimaging of calculation in aphasia

The role of language in exact calculation is the subject of debate. Some behavioral and functional neuroimaging investigations of healthy participants suggest that calculation requires language resources. However, there are also reports of individuals with severe aphasic language impairment who retain calculation ability. One possibility in resolving these discordant findings is that the neural basis of calculation has undergone significant reorganization in aphasic calculators. Using fMRI, we examined brain activations associated with exact addition and subtraction in two patients with severe agrammatic aphasia and retained calculation ability. Behavior and brain activations during two-digit addition and subtraction were compared to those of a group of 11 healthy, age-matched controls. Behavioral results confirmed that both patients retained calculation ability. Imaging findings revealed individual differences in processing, but also a similar activation pattern across patients and controls in bilateral parietal cortices. Patients differed from controls in small areas of increased activation in peri-lesional regions, a shift from left fronto-temporal activation to the contralateral region, and increased activations in bilateral superior parietal regions. Our results suggest that bilateral parietal cortex represents the core of the calculation network and, while healthy controls may recruit language resources to support calculation, these mechanisms are not mandatory in adult cognition.     

Modulating younger and older adults’ performance in ignoring pictorial information during a word matching task

Using both behavioural and event-related potential (ERP) data, the current study sought to examine the neurophysiological underpinnings for the effect of distracting pictorial information on semantic word matching performance in younger and older adults. This was tested in the context of semantic relations between task-relevant word pairs, a task-irrelevant picture and the resultant N400 differences in ERP. Younger and older adults were shown a context word superimposed on a to-be-ignored picture, followed by a test word. Their task was to determine whether the prime and test words were semantically related. The to-be-ignored pictures were interfering (for ‘No’ trials), facilitating (for ‘Yes’ trials), or neutral (for both ‘Yes’ and ‘No’ trials) to the expected responses. The interfering and facilitatory effects of to-be-ignored pictures were assessed under more automatic and more controlled conditions by manipulating the context–test interstimulus-interval (ISI) as 50 ms and 1000 ms, respectively. The analysis of the N400 at centro-parietal sites during test word display revealed similar N400 amplitudes for the ‘No’ response trials at the two ISIs, suggesting that younger and older adults showed an equivalent effect from interfering pictures. In contrast, younger adults showed greater reductions in the N400, as compared to older adults, for ‘Yes’ trials indicating differential effects in facilitation from to-be-ignored pictorial information, but only in the long ISI condition. The data are discussed in terms of age differences in resource demanding strategy use during a semantic word matching task, specifically during controlled retrieval.     

The Evangelical Necessity of Creedal Confession in the World of Empire

The author argues that in the world of Empire where greed, violence, and idolatry pervade, the Church is challenged to recognise that it exists to witness to the radical, liberating message of the gospel of the crucified and risen Lord, Jesus Christ. The Church is challenged to recognise and acknowledge how it is a beneficiary of Empire, but that its focus is to be on the Lord Jesus Christ and not the ‘Caesars’ who cannot give the life, healing, and forgiveness that only God can give. Faithfulness to the gospel calls for creedal‐confession that becomes both inevitable and necessary because the church's confession is communal. The community in Christ needs one another in order to be faithful through mutual creedal‐remembering and reminding of the identity of the God of Jesus Christ.     

Perception—Action Coupling during Bimanual Coordination: The Role of Visual Perception in the Coalition of Constraints That Govern Bimanual Action

Constraints pertaining to interlimb coordination have been studied extensively in the past decades. In this debate, F. Mechsner (2004) has taken a provocative position by putting primary emphasis on perceptual principles that mediate coordinative stability. Whereas the present authors agree that the role of perceptual principles is of critical importance during coordination, they take issue with Mechsner's extreme position and with the evidence forwarded to support a purely perceptual-cognitive approach to bimanual coordination. More specifically, the authors emphasize that current knowledge about brain function argues against a dualism between perception and action, criticize the presented evidence that posture manipulations during coordination provide decisive evidence against motoric and muscular constraints, and report on potential pitfalls associated with the use of visual transformation procedures to support complex coordination patterns.