4,414 research outputs found

    Effects of Projected Changes in Wind, Atmospheric Temperature, and Freshwater Inflow on the Ross Sea

    Get PDF
    A 5-km horizontal resolution regional ocean-sea ice-ice shelf model of the Ross Sea is used to examine the effects of changes in wind strength, air temperature, and increased meltwater input on the formation of high-salinity shelf water (HSSW), on-shelf transport and vertical mixing of Circumpolar Deep Water (CDW) and its transformation into modified CDW (MCDW), and basal melt of the Ross Ice Shelf (RIS). A 20% increase in wind speed, with no other atmospheric changes, reduced summer sea ice minimum area by 20%, opposite the observed trend of the past three decades. Increased winds with spatially uniform, reduced atmospheric temperatures increased summer sea ice concentrations, on-shelf transport of CDW, vertical mixing of MCDW, HSSW volume, and (albeit small) RIS basal melt. Winds and atmospheric temperatures from the SRES A1B scenario forcing of the MPI ECHAM5 model decreased on-shelf transport of CDW and vertical mixing of MCDW for 2046-61 and 2085-2100 relative to the end of the twentieth century. The RIS basal melt increased slightly by 2046-61 (9%) and 2085-2100 (13%). Advection of lower-salinity water onto the continental shelf did not significantly affect sea ice extent for the 2046-61 or 2085-2100 simulations. However, freshening reduces on-shelf transport of CDW, vertical mixing of MCDW, and the volume of HSSW produced. The reduced vertical mixing of MCDW, while partially balanced by the reduced on-shelf transport of CDW, enhances the RIS basal melt rate relative to the twentieth-century simulation for 2046-61 (13%) and 2085-2100 (17%)

    ciliaFA : a research tool for automated, high-throughput measurement of ciliary beat frequency using freely available software

    Get PDF
    Background: Analysis of ciliary function for assessment of patients suspected of primary ciliary dyskinesia (PCD) and for research studies of respiratory and ependymal cilia requires assessment of both ciliary beat pattern and beat frequency. While direct measurement of beat frequency from high-speed video recordings is the most accurate and reproducible technique it is extremely time consuming. The aim of this study was to develop a freely available automated method of ciliary beat frequency analysis from digital video (AVI) files that runs on open-source software (ImageJ) coupled to Microsoft Excel, and to validate this by comparison to the direct measuring high-speed video recordings of respiratory and ependymal cilia. These models allowed comparison to cilia beating between 3 and 52 Hz. Methods: Digital video files of motile ciliated ependymal (frequency range 34 to 52 Hz) and respiratory epithelial cells (frequency 3 to 18 Hz) were captured using a high-speed digital video recorder. To cover the range above between 18 and 37 Hz the frequency of ependymal cilia were slowed by the addition of the pneumococcal toxin pneumolysin. Measurements made directly by timing a given number of individual ciliary beat cycles were compared with those obtained using the automated ciliaFA system. Results: The overall mean difference (± SD) between the ciliaFA and direct measurement high-speed digital imaging methods was −0.05 ± 1.25 Hz, the correlation coefficient was shown to be 0.991 and the Bland-Altman limits of agreement were from −1.99 to 1.49 Hz for respiratory and from −2.55 to 3.25 Hz for ependymal cilia. Conclusions: A plugin for ImageJ was developed that extracts pixel intensities and performs fast Fourier transformation (FFT) using Microsoft Excel. The ciliaFA software allowed automated, high throughput measurement of respiratory and ependymal ciliary beat frequency (range 3 to 52 Hz) and avoids operator error due to selection bias. We have included free access to the ciliaFA plugin and installation instructions in Additional file 1 accompanying this manuscript that other researchers may use

    Affective state influences retrieval-induced forgetting for integrated knowledge

    Get PDF
    Selectively testing parts of learned materials can impair later memory for nontested materials. Research has shown that such retrieval-induced forgetting occurs for low-integrated materials but may be prevented for high-integrated materials. However, previous research has neglected one factor that is ubiquitous in real-life testing: affective stat

    Preliminary Limits on the WIMP-Nucleon Cross Section from the Cryogenic Dark Matter Search (CDMS)

    Get PDF
    We are conducting an experiment to search for WIMPs, or weakly-interacting massive particles, in the galactic halo using terrestrial detectors. This generic class of hypothetical particles, whose properties are similar to those predicted by extensions of the standard model of particle physics, could comprise the cold component of non-baryonic dark matter. We describe our experiment, which is based on cooled germanium and silicon detectors in a shielded low-background cryostat. The detectors achieve a high degree of background rejection through the simultaneous measurement of the energy in phonons and ionization. Using exposures on the order of one kilogram-day from initial runs of our experiment, we have achieved (preliminary) upper limits on the WIMP-nucleon cross section that are comparable to much longer runs of other experiments.Comment: 5 LaTex pages, 5 eps figs, epsf.sty, espcrc2dsa2.sty. Proceedings of TAUP97, Gran Sasso, Italy, 7-11 Sep 1997, Nucl. Phys. Suppl., A. Bottino, A. di Credico and P. Monacelli (eds.). See also http://cfpa.berkeley.ed

    Higher incidence of clear cell adenocarcinoma of the cervix and vagina among women born between 1947 and 1971 in the United States

    Get PDF
    Although the association between in utero exposure to diethylstilbestrol (DES) and clear cell adenocarcinoma of the cervix and vagina (CCA) was first reported among young women, subsequent case reports and cohort studies suggest that an elevated risk for CCA may persist with age. Data from the National Program of Cancer Registries (NPCR) and the Surveillance, Epidemiology and End Results (SEER) Program were used to construct indirect standardized incidence ratios (SIR) comparing CCA risk among women born during the exposure period 1947 through 1971, when DES was prescribed to pregnant women, to the relevant time period for nonexposed women born before or after DES exposure period. CCA incidence among the women born before the DES exposure period (ages 30–54 at diagnosis of CAA) or after the DES exposure period (ages 15–29 at diagnosis) were used to calculate the expected rates for women born during the DES exposure period. Among women aged 15–29 years, CCA risk increased with age and peaked in the 25–29 year age group, but the risk estimates were unstable (SIR = 6.06; 95% CI: 0.97, −251.07, SEER data). Among women aged 40–54 years, CCA risk was greatest in the 40–44 year age group (SIR = 4.55; 95% CI: 1.11, 40.19, SEER data and SIR = 3.94; 95% CI: 1.06, 33.01, NPCR/SEER data) and remained significantly elevated throughout this age group in the combined data set. Risk was not elevated among women aged 30–39 years. The observed risk of CCA, if causally related to DES exposure, reflects a persistent health impact from in utero exposure that is widespread in the general population. When assessing a woman’s cancer risks, whether her mother took DES while pregnant may still be a relevant aspect of the medical history for women born during the period of DES use in pregnancy

    Health services research in the public healthcare system in Hong Kong: An analysis of over 1 million antihypertensive prescriptions between 2004-2007 as an example of the potential and pitfalls of using routinely collected electronic patient data

    Get PDF
    <b>Objectives</b> Increasing use is being made of routinely collected electronic patient data in health services research. The aim of the present study was to evaluate the potential usefulness of a comprehensive database used routinely in the public healthcare system in Hong Kong, using antihypertensive drug prescriptions in primary care as an example.<p></p> <b>Methods</b> Data on antihypertensive drug prescriptions were retrieved from the electronic Clinical Management System (e-CMS) of all primary care clinics run by the Health Authority (HA) in the New Territory East (NTE) cluster of Hong Kong between January 2004 and June 2007. Information was also retrieved on patients’ demographic and socioeconomic characteristics, visit type (new or follow-up), and relevant diseases (International Classification of Primary Care, ICPC codes). <p></p> <b>Results</b> 1,096,282 visit episodes were accessed, representing 93,450 patients. Patients’ demographic and socio-economic details were recorded in all cases. Prescription details for anti-hypertensive drugs were missing in only 18 patients (0.02%). However, ICPC-code was missing for 36,409 patients (39%). Significant independent predictors of whether disease codes were applied included patient age > 70 years (OR 2.18), female gender (OR 1.20), district of residence (range of ORs in more rural districts; 0.32-0.41), type of clinic (OR in Family Medicine Specialist Clinics; 1.45) and type of visit (OR follow-up visit; 2.39). <p></p> In the 57,041 patients with an ICPC-code, uncomplicated hypertension (ICPC K86) was recorded in 45,859 patients (82.1%). The characteristics of these patients were very similar to those of the non-coded group, suggesting that most non-coded patients on antihypertensive drugs are likely to have uncomplicated hypertension. <p></p> <b>Conclusion</b> The e-CMS database of the HA in Hong Kong varies in quality in terms of recorded information. Potential future health services research using demographic and prescription information is highly feasible but for disease-specific research dependant on ICPC codes some caution is warranted. In the case of uncomplicated hypertension, future research on pharmaco-epidemiology (such as prescription patterns) and clinical issues (such as side-effects of medications on metabolic parameters) seems feasible given the large size of the data set and the comparability of coded and non-coded patients

    Predicting residents' performance: A prospective study

    Get PDF
    BACKGROUND: Objective criteria for predicting residents' performance do not exist. The purpose of this study was to test the hypothesis that global assessment by an intern selection committee (ISC) would correlate with the future performance of residents. METHODS: A prospective study of 277 residents between 1992 and 1999. Global assessment at the time of interview was compared to subsequent clinical (assessed by chief residents) and cognitive performance (assessed by the American Board of Pediatrics in-service training examination). RESULTS: ISC ratings correlated significantly with clinical performance at 24 and 36 months of training (r = 0.58, P < .001; and r = 0.60, P < .001 respectively). ISC ratings also correlated significantly with in-service exam scores in the 1(st), 2(nd), and 3(rd) years of training (r = 0.35, P = .0016; r = 0.39, P = 0.0003; r = 0.50, P = 0.005 respectively). CONCLUSIONS: Global assessment by an ISC predicted residents' clinical and cognitive performances

    Gliosarcoma: a study of four cases

    Get PDF
    Gliosarcomas (GS) are highly malignant and rare tumors of the central nervous system with a poor prognosis. We report here on four patients with GS, the median survival for whom was 9.25 months. Prognosis of GS remains poor, and a multidisciplinary approach (surgery, radiation therapy, and chemotherapy) seems to be associated with slightly more prolonged survival times

    Immunotherapy with ponezumab for probable cerebral amyloid angiopathy

    Get PDF
    Objective: Cerebral amyloid angiopathy (CAA) is caused by cerebrovascular deposition of β‐amyloid fragments leading to cerebrovascular dysfunction and other brain injuries. This phase 2, randomized, double–blind trial in patients with probable CAA assessed the efficacy and safety of ponezumab, a novel monoclonal antibody against Aβ1–40. Methods: Thirty‐six participants aged 55–80 years with probable CAA received intravenous placebo (n = 12) or ponezumab (n = 24). The change from baseline to Days 2 and 90 in cerebrovascular reactivity (CVR) was measured in the visual cortex as the natural log of the rising slope of the BOLD fMRI response to a visual stimulus. Safety and tolerability were also assessed. Results: The mean change from baseline to Day 90 was 0.817 (ponezumab) and 0.958 (placebo): a mean ratio of 0.852 (90% CI 0.735–0.989) representing a trend towards reduced CVR in the ponezumab group. This trend was not present at Day 2. There was one asymptomatic occurrence of amyloid–related imaging abnormality–edema in the ponezumab group. The total number of new cerebral microbleeds from baseline to day 90 did not differ between groups. The ponezumab group had a participant with nonfatal new cerebral hemorrhage with aphasia and a participant with subdural hemorrhage that site investigators deemed to be nondrug related. In the placebo group one participant had a fatal intracerebral hemorrhage and one participant had migraine with aura

    Comparative genomics of isolates of a pseudomonas aeruginosa epidemic strain associated with chronic lung infections of cystic fibrosis patients

    Get PDF
    Pseudomonas aeruginosa is the main cause of fatal chronic lung infections among individuals suffering from cystic fibrosis (CF). During the past 15 years, particularly aggressive strains transmitted among CF patients have been identified, initially in Europe and more recently in Canada. The aim of this study was to generate high-quality genome sequences for 7 isolates of the Liverpool epidemic strain (LES) from the United Kingdom and Canada representing different virulence characteristics in order to: (1) associate comparative genomics results with virulence factor variability and (2) identify genomic and/or phenotypic divergence between the two geographical locations. We performed phenotypic characterization of pyoverdine, pyocyanin, motility, biofilm formation, and proteolytic activity. We also assessed the degree of virulence using the Dictyostelium discoideum amoeba model. Comparative genomics analysis revealed at least one large deletion (40-50 kb) in 6 out of the 7 isolates compared to the reference genome of LESB58. These deletions correspond to prophages, which are known to increase the competitiveness of LESB58 in chronic lung infection. We also identified 308 non-synonymous polymorphisms, of which 28 were associated with virulence determinants and 52 with regulatory proteins. At the phenotypic level, isolates showed extensive variability in production of pyocyanin, pyoverdine, proteases and biofilm as well as in swimming motility, while being predominantly avirulent in the amoeba model. Isolates from the two continents were phylogenetically and phenotypically undistinguishable. Most regulatory mutations were isolate-specific and 29% of them were predicted to have high functional impact. Therefore, polymorphism in regulatory genes is likely to be an important basis for phenotypic diversity among LES isolates, which in turn might contribute to this strain's adaptability to varying conditions in the CF lung
    corecore