Polymer matrix composites on LDEF experiments M0003-9 and M0003-10

Over 250 polymer matrix composites were exposed to the natural space environment on Long Duration Exposure Facility (LDEF) experiments M0003-9 and 10. The experiments included a wide variety of epoxy, thermoplastic, polyimide, and bismalimide matrix composites reinforced with graphite, glass, or organic fibers. A review of the significant observations and test results obtained to date is presented. Estimated recession depths from atomic oxygen exposure are reported and the resulting surface morphologies are discussed. The effects of the LDEF exposure on the flexural strength and modulus, short beam shear strength, and coefficient of thermal expansion of several classes of bare and coated composites are reviewed. Lap shear data are presented for composite-to-composite and composite-to-aluminum alloy samples that were prepared using different bonding techniques and subsequently flown on LDEF

Discourse-based Instructional Strategies to Engage Middle School Students With Standards for Mathematical Practice

Student achievement in mathematics is correlated with factors related to student engagement. Improving engagement has the potential to improve student achievement at the middle school level. The Common Core State Standards for Mathematics explicate eight specific Standards for Mathematical Practice (SMPs) that clarify the types of skills and learning dispositions associated with mathematical proficiency. The CCSS further urge teachers to engage students through pedagogical practices that provide opportunities to use the SMPs in increasingly complex ways. This study aims to identify how discourse is used as an instructional strategy to engage middle school mathematics students with the SMPs. Data was collected through a qualitative case study of a middle school mathematics teachers teaching five classes of mathematics to students at three grade levels. Instructional activities should be thoughtfully planned to emphasize independence and perseverance. A delicate balance of independent work and group interactions can support these dual goals. While discourse provides an opportunity to monitor students’ engagement with many of the SMPs, thoughtfully planned activities and questioning routines help to guide the discussions toward the intended learning target

Snca and Bdnf gene expression in the VTA and raphe nuclei of midbrain in chronically victorious and defeated male mice

The study aimed to analyze the mRNA levels of Snca and Bdnf genes in the ventral tegmental area (VTA) and raphe nuclei of the midbrain in male mice that had each won or defeated 20 encounters in daily agonistic interactions. Groups of animals that had the same winning and losing track record followed by a no-fight period for 14 days were also studied. Snca mRNA levels were increased in the raphe nuclei in the losers and in the VTA of the winners. After fighting deprivation Snca mRNA levels were decreased to the control level in both groups. Snca mRNA levels were similar to the control level in the VTA of the losers and in the raphe nuclei of the winners. However Snca gene expression was increased in these areas after no-fight period in the winners and losers in comparison with respective mRNA levels in the undeprived animals. Significant positive correlations were found between the mRNA levels of Snca and Bdnf genes in the raphe nuclei. It was concluded, that social experience affects Snca gene expression depending on brain areas and functional activity of monoaminergic systems in chronically victorious or defeated mice

Waiting times and socioeconomic status: evidence from England

Waiting times for elective surgery, like hip replacement, are often referred to as an equitable rationing mechanism in publicly-funded healthcare systems because access to care is not based on socioeconomic status. Previous work has established that that this may not be the case and there is evidence of inequality in NHS waiting times favouring patients living in the least deprived neighbourhoods in England. We advance the literature by explaining variations of inequalities in waiting times in England in four different ways. First, we ask whether inequalities are driven by education rather than income. Our analysis shows that education and income deprivation have distinct effects on waiting time. Patients in the first quintile with least deprivation in education wait 9% less than patients in the second quintile and 14% less than patients in the third-to-fifth quintile. Patients in the fourth and fifth most income-deprived quintile wait about 7% longer than patients in the least deprived quintile. Second, we investigate whether inequalities arise "across" hospitals or "within" the hospital. The analysis provides evidence that most inequalities occur within hospitals rather than across hospitals. Moreover, failure to control for hospital fixed effects results in underestimation of the income gradient. Third, we explore whether inequalities arise across the entire waiting time distribution. Inequalities between better educated patients and other patients occur over large part of the waiting time distribution. Moreover we find that the education gradient becomes smaller for very long waiting. Fourth, we investigate whether the gradient may reflect the fact that patients with higher socioeconomic status have a different severity as proxied through a range of types and the number of diagnoses (in addition to age and gender) compared to those with lower socioeconomic status. We find no evidence that differences in severity explain the social gradient in waiting times

The role of microbiology and pharmacy departments in the stewardship of antibiotic prescribing in European hospitals

This observational, cross-sectional study describes the role played by clinical microbiology and pharmacy departments in the stewardship of antibiotic prescribing in European hospitals. A total of 170 acute care hospitals from 32 European countries returned a questionnaire on antibiotic policies and practices implemented in 2001. Data on antibiotic use, expressed as De.ned Daily Doses per 100 occupied bed-days (DDD/100 BD) were provided by 139 hospitals from 30 countries. A total of 124 hospitals provided both datasets. 121 (71%) of Clinical Microbiology departments and 66 (41%) of Pharmacy departments provided out of hours clinical advice. 70 (41%) of microbiology/infectious disease specialists and 28 (16%) of pharmacists visited wards on a daily basis. The majority of laboratories provided monitoring of blood cultures more than once per day and summary data of antibiotic susceptibility testing (AST) for empiric prescribing (86% and 73% respectively). Most of the key laboratory and pharmacy-led initiatives examined did not vary signi.cantly by geographical location. Hospitals from the North and West of Europe were more likely to examine blood cultures more than once daily compared with other regions (p < 0.01). Hospitals in the North were least likely routinely to report susceptibility results for restricted antibiotics compared to those in the South-East and Central/Eastern Europe (p < 0.01). Hospital wards in the North were more likely to hold antibiotic stocks (100%) compared with hospitals in the South-East which were least likely (39%) (p < 0.001). Conversely, hospital pharmacies in the North were least likely to dispense antibiotics on an individual patient basis (16%) compared with hospital pharmacies from Southern Europe (60%) (p = 0.01). Hospitals that routinely reported susceptibility results for restricted antibiotics had signi.cantly lower median total antibiotic use in 2001 (p < 0.01). Hospitals that provided prescribing advice outside normal working hours had signi.cantly higher antibiotic use compared with institutions that did not provide this service (p = 0.01). A wide range of antibiotic stewardship measures was practised in the participating hospitals in 2001, although there remains great scope for expansion of those overseen by pharmacy departments. Most hospitals had active antibiotic stewardship programmes led by specialists in infection, although there is no evidence that these were associated with reduced antibiotic consumption. There was also no evidence that pharmacy services reduced the amount of antibiotics prescribed.The ARPAC study was funded by the European Commission (project QLK2-CT-2001-00915). F.M. MacKenzie was supported by the European Study Group on Antibiotic Policies to write this manuscript

Is there a difference in artistic ability between learning -disabled students and "regular-class" students?

Research and practice regarding LO students usually has focussed upon defining and supplementing deficiencies rather than seeking unique talents and capability patterns for learning and expression. This study examined nine dimensions that may constitute artistic or creative talent and compared LDs with "regular-class" students, pair-wise and as groups, for levels and distributions of the dimensions. For 14 LO and 9 "regular-class" elementary-school subjects, both genders, data were taken by direct observation, from a standardized test and assessments by two practicing artists. Assessments by artists were in concord. LOs improved more in "Composition". No other significant class, age or gender-related differences were found

Neural mechanisms for stimulus-response preparation

Human behavior relies on the accumulation of task-relevant information to narrow the range of possible responses to a single response. How do we utilize advance information that can help us select and prepare responses to a task? How is this performance benefit facilitated in the brain? Previous literature suggests a subset of brain regions involved in cue-specific processing. We investigated how informative cues affect brain processing. Specifically, to what extent is activity modulated for stimulus-related and response-related cues versus neutral cues in control- and processing-related regions? Participants made manual responses to the identity of face or place stimuli in a variation of the response cuing paradigm while fMRI BOLD signal was recorded. Prior to the stimulus, a letter cue indicating the upcoming stimulus type (face or place) or response hand (left or right) or a neutral cue was presented. We proposed three hypotheses: 1) control-related activity (e.g., prefrontal, parietal) would increase for cued vs. uncued trials; 2) activity in face and place processing regions and left and right premotor regions would activate for their respective cues, although all cues were letters; and 3) stimulus processing regions would also be activated by response cues, and vice versa.M.S