2,475 research outputs found

    Slow light in paraffin-coated Rb vapor cells

    Full text link
    We present preliminary results from an experimental study of slow light in anti-relaxation-coated Rb vapor cells, and describe the construction and testing of such cells. The slow ground state decoherence rate allowed by coated cell walls leads to a dual-structured electromagnetically induced transparency (EIT) spectrum with a very narrow (<100 Hz) transparency peak on top of a broad pedestal. Such dual-structure EIT permits optical probe pulses to propagate with greatly reduced group velocity on two time scales. We discuss ongoing efforts to optimize the pulse delay in such coated cell systems.Comment: 6 pages, 6 figures, submitted to Journal of Modern Optic

    Conscious thought beats deliberation without attention in diagnostic decision-making: at least when you are an expert

    Get PDF
    Contrary to what common sense makes us believe, deliberation without attention has recently been suggested to produce better decisions in complex situations than deliberation with attention. Based on differences between cognitive processes of experts and novices, we hypothesized that experts make in fact better decisions after consciously thinking about complex problems whereas novices may benefit from deliberation-without-attention. These hypotheses were confirmed in a study among doctors and medical students. They diagnosed complex and routine problems under three conditions, an immediate-decision condition and two delayed conditions: conscious thought and deliberation-without-attention. Doctors did better with conscious deliberation when problems were complex, whereas reasoning mode did not matter in simple problems. In contrast, deliberation-without-attention improved novices’ decisions, but only in simple problems. Experts benefit from consciously thinking about complex problems; for novices thinking does not help in those cases

    Severe hydrops in the infant of a Rhesus D-positive mother due to anti-c antibodies diagnosed antenatally: a case report

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>Rhesus haemolytic disease of the newborn is a prototype of maternal isoimmunisation and fetal haemolytic disease. There are other rare blood group antigens capable of causing alloimmunisation and haemolytic disease such as c, C, E, Kell and Duffy. In India, after the confirmation of a newborn's blood group, antibodies are screened only if the mother is Rehsus D-negative negative and the father is Rhesus D-positive. Hydrops in Rhesus positive women are investigated along the lines of non-immune hydrops.</p> <p>Case presentation</p> <p>We report the case of a patient from India where irregular antibodies were requested for an O-positive 26-year-old mother in order to investigate fetal hydrops. Anti-c antibody was revealed and the fetus was treated successfully with compatible O negative and c negative intrauterine blood transfusions. The baby was treated postnatally with double volume exchange transfusion with the same compatible blood, and was discharged 30 days after birth.</p> <p>Conclusion</p> <p>We highlight the importance of conducting irregular antibody screening for women with significant obstetric history and fetal hydrops. This could assist in diagnosing and successfully treating the fetus with appropriate antigen negative cross-matched compatible blood. We note, however, that anti-c immunoglobulin is not yet readily available.</p

    Life histories of the copepods Pseudocalanus minutus, P. acuspes (Calanoida) and Oithona similis (Cyclopoida) in the Arctic Kongsfjorden (Svalbard)

    Get PDF
    The year-round variation in abundance and stage-specific (vertical) distribution of Pseudocalanus minutus and Oithona similis was studied in the Arctic Kongsfjorden, Svalbard. Maxima of vertically integrated abundance were found in November with 111,297 ind m−2 for P. minutus and 704,633 ind m−2 for O. similis. Minimum abundances comprised 1,088 ind m−2 and 4,483 ind m−2 in June for P. minutus and O. similis, respectively. The congener P. acuspes only occurred in low numbers (15–213 ind m−2), and successful reproduction was debatable. Reproduction of P. minutus took place in May/June, and stage distribution revealed a 1-year life cycle with copepodids CIII, CIV, and CV as the overwintering stages. Oithona similis exhibited two main reproductive peaks in June and August/September, respectively. Moreover, it reproduced more or less continuously throughout the whole year with all stages occurring during the entire sampling period, suggesting two generations per year. Both species migrated towards greater depth in November, but O. similis preferred to stay longer in the upper 100 m as compared to Pseudocalanus. The reproduction of the two species in Kongsfjorden seemed to be linked to phytoplankton dynamics

    The Use of a Disclosing Agent During Resective Periodontal Surgery for Improved Removal of Biofilm

    Get PDF
    A total removal of the bacterial deposits is one of the main challenges of periodontal therapy. A surgical approach is sometimes required in order to allow a correct access to the areas not thoroughly reached during the initial therapy. The present study focuses on the surgical scaling effectiveness in root deposits removal; the potential support of a disclosing agent during this procedure is also evaluated. Forty surgical periodontal patients were randomly divided between surgeries where the operator was informed about a final examination of the residual root deposits and surgeries where the operator was not informed. Straight after scaling procedures a supervisor recorded the O’Leary Plaque Index of the exposed roots by mean of a disclosing agent and the percentage of teeth with residual biofilm. After the stained deposits removal, a second chromatic examination was performed and new data were collected. Mann-Whitney U-test and Wilcoxon test for paired samples were used for comparisons respectively between the two surgery groups and the first and the second chromatic examination; one-sided p-value was set at 0.05. At first examination no significant differences between the two groups were observed regarding Plaque Index (p=0.24) and percentages of teeth with residual biofilm (p=0.07). The 100% removal of roots deposits was never achieved during the study but a significant reduction of 80% of root deposits was observed between first and second examination (p=0.0001). Since root deposits removal during periodontal surgery resulted always suboptimal, the use of a disclosing agent during this procedure could be a useful and practical aid

    Birth weight and cognitive performance in older women: the Rancho Bernardo study

    Get PDF
    Low birth weight is associated with poorer cognitive function from infancy through early adulthood, but little is known about low birth weight and cognitive performance in the elderly. This study examines the association of birth weight with cognitive function in community-dwelling older women. Participants were 292 community-dwelling women aged 55–89 (median = 71 years) who attended a 1988–91 clinic visit when cognitive function was assessed, and responded to a 1991 mailed questionnaire assessing birth weight. All analyses were adjusted for age and education. Birth weight ranged from 2 to 12 pounds (lbs; mean = 7.4 ± 1.9). When birth weight was categorized into tertiles (2–6.9 lbs, 7–8 lbs, and 8.1–12.4 lbs), women in the lowest tertile had significantly lower (“poorer”) scores on Serial 7’s, a test of concentration and calculation (p < 0.05). Other birth weight categorizations (lowest quartile or quintile, or birth weight <5.5 lbs vs. 5.6–8.9 lbs and ≄9 lbs) did not improve the prediction of poor performance on Serial 7’s. Birth weight as a continuous variable was significantly and positively associated with Serial 7’s test scores (p = 0.04). Results suggest that small decrements in cognitive function tasks involving calculation may persist throughout life in women who were of relatively low birth weight. Although this association could be spurious, it deserves further evaluation

    Observation of an Exotic S=+1S=+1 Baryon in Exclusive Photoproduction from the Deuteron

    Full text link
    In an exclusive measurement of the reaction Îłd→K+K−pn\gamma d \to K^+ K^- p n, a narrow peak that can be attributed to an exotic baryon with strangeness S=+1S=+1 is seen in the K+nK^+n invariant mass spectrum. The peak is at 1.542±0.0051.542\pm 0.005 GeV/c2^2 with a measured width of 0.021 GeV/c2^2 FWHM, which is largely determined by experimental mass resolution. The statistical significance of the peak is 5.2±0.6σ5.2 \pm 0.6 \sigma. The mass and width of the observed peak are consistent with recent reports of a narrow S=+1S=+1 baryon by other experimental groups.Comment: 5 pages, 5 figure

    What we talk about when we talk about "global mindset": managerial cognition in multinational corporations

    Get PDF
    Recent developments in the global economy and in multinational corporations have placed significant emphasis on the cognitive orientations of managers, giving rise to a number of concepts such as “global mindset” that are presumed to be associated with the effective management of multinational corporations (MNCs). This paper reviews the literature on global mindset and clarifies some of the conceptual confusion surrounding the construct. We identify common themes across writers, suggesting that the majority of studies fall into one of three research perspectives: cultural, strategic, and multidimensional. We also identify two constructs from the social sciences that underlie the perspectives found in the literature: cosmopolitanism and cognitive complexity and use these two constructs to develop an integrative theoretical framework of global mindset. We then provide a critical assessment of the field of global mindset and suggest directions for future theoretical and empirical research
    • 

    corecore