13,223 research outputs found

    Reproducibility of the bronchoconstrictive response to eucapnic voluntary hyperpnoea

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    Background: Eucapnic voluntary hyperpnoea (EVH) is considered an effective bronchoprovocation challenge for identifying exercise-induced bronchoconstriction (EIB). However, the reproducibility of the hyperpnoea-induced bronchoconstriction (HIB) response elicited by EVH remains unknown and was therefore the focus of this study. Methods: Two cohorts of 16 physically active males (each cohort comprised 8 controls and 8 with physician diagnosis of asthma) participated in two studies of the short- and long-term reproducibility of the bronchoconstrictive response to an EVH test with dry air. EVH was performed on days 0, 7, 14, and 21 (short-term study), and 0, 35, and 70 (long-term study). HIB was diagnosed by a ≥10% fall in forced expiratory volume in 1 s (FEV1) after EVH. Results: On day 0 of the short-term study, FEV1 fell by 2 ± 1% (P < 0.05) and 27 ± 18% (P < 0.01) from pre-to post-EVH in control and HIB-positive groups respectively. The post-EVH fall in FEV1 did not differ across the short-term study test days. In the HIB-positive group, the day-to-day coefficient of variation, reproducibility, and smallest meaningful change for the fall in FEV1 were 12%, 328 mL, and 164 mL, respectively. On day 0 of the long-term study, FEV1 fell by 2 ± 2% and 25 ± 18% (P < 0.01) after EVH in control and HIB-positive groups respectively. The post-EVH fall in FEV1 did not differ across the long-term study test days. In the HIB-positive group, the day-to-day coefficient of variation, reproducibility, and smallest meaningful change for the fall in FEV1 were 10%, 196 mL, and 98 mL respectively. Conclusion: The EVH test elicits a reproducible bronchoconstrictive response in physically active males with physician diagnosed asthma. These data thus support the clinical utility of the EVH test for EIB screening and monitoring

    Midday measurements of leaf water potential and stomatal conductance are highly correlated with daily water use of Thompson Seedless grapevines

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    A study was conducted to determine the relationship between midday measurements of vine water status and daily water use of grapevines measured with a weighing lysimeter. Water applications to the vines were terminated on August 24th for 9 days and again on September 14th for 22 days. Daily water use of the vines in the lysimeter (ETLYS) was approximately 40 L vine−1 (5.3 mm) prior to turning the pump off, and it decreased to 22.3 L vine−1 by September 2nd. Pre-dawn leaf water potential (ΨPD) and midday Ψl on August 24th were −0.075 and −0.76 MPa, respectively, with midday Ψl decreasing to −1.28 MPa on September 2nd. Leaf g s decreased from ~500 to ~200 mmol m−2 s−1 during the two dry-down periods. Midday measurements of g s and Ψl were significantly correlated with one another (r = 0.96) and both with ETLYS/ETo (r = ~0.9). The decreases in Ψl, g s, and ETLYS/ETo in this study were also a linear function of the decrease in volumetric soil water content. The results indicate that even modest water stress can greatly reduce grapevine water use and that short-term measures of vine water status taken at midday are a reflection of daily grapevine water us

    Service evaluation to establish the sensitivity, specificity and additional value of broad-range 16S rDNA PCR for the diagnosis of infective endocarditis from resected endocardial material in patients from eight UK and Ireland hospitals

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    Infective endocarditis (IE) can be diagnosed in the clinical microbiology laboratory by culturing explanted heart valve material. We present a service evaluation that examines the sensitivity and specificity of a broad-range 16S rDNA polymerase chain reaction (PCR) assay for the detection of the causative microbe in culture-proven and culture-negative cases of IE. A clinical case-note review was performed for 151 patients, from eight UK and Ireland hospitals, whose endocardial specimens were referred to the Microbiology Laboratory at Great Ormond Street Hospital (GOSH) for broad-range 16S rDNA PCR over a 12-year period. PCR detects the causative microbe in 35/47 cases of culture-proven IE and provides an aetiological agent in 43/69 cases of culture-negative IE. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the 16S rDNA PCR assay were calculated for this series of selected samples using the clinical diagnosis of IE as the reference standard. The values obtained are as follows: sensitivity = 67 %, specificity = 91 %, PPV = 96 % and NPV = 46 %. A wide range of organisms are detected by PCR, with Streptococcus spp. detected most frequently and a relatively large number of cases of Bartonella spp. and Tropheryma whipplei IE. PCR testing of explanted heart valves is recommended in addition to culture techniques to increase diagnostic yield. The data describing the aetiological agents in a large UK and Ireland series of culture-negative IE will allow future development of the diagnostic algorithm to include real-time PCR assays targeted at specific organisms

    Personal area technologies for internetworked services

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    Potential for Detection of Safety Signals for Over-the-Counter Medicines Using National ADR Spontaneous Reporting Data: The Example of OTC NSAID-Associated Gastrointestinal Bleeding.

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    One post-marketing surveillance challenge for many regulatory authorities is access to information regarding the safety of over-the-counter (OTC) medicines. National spontaneous adverse drug reaction (ADR) report data represent a rich potential data source for the detection of safety signals associated with OTC medicines, yet little is known regarding the possibility of detecting safety signals for OTC medicines within these datasets. The aim of this study was to evaluate the potential for detecting safety signals for OTC medicines in National ADR spontaneous reporting data, using OTC non-steroidal anti-inflammatory drugs (NSAIDs) and gastrointestinal bleeding as an example. Data from the Australian Adverse Drug Reactions System (ADRS) dataset (1971-2008) and the Canadian Vigilance Adverse Reaction Online Database (VAROD) (1965-2013) were used to explore the feasibility of using spontaneous reporting data, exploring the association between gastrointestinal bleeding and the use of OTC NSAIDs. Safety signals were examined using disproportionality analyses and reporting odds ratios calculated. After adjusting for age, gender, medications known to increase the risk of bleeding, and medications used for the management of conditions associated with an increased risk of bleeding, a two-fold increase in the risk of gastrointestinal (GI) bleeding with OTC NSAID was observed within each dataset. This study demonstrates that spontaneous ADR reporting data can be used in pharmacovigilance to monitor the safety of OTC medicines

    Design of 100 GHz-class Mach-Zehnder modulators in a generic indium phosphide platform

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    We propose a push-pull electrode design for a Mach-Zehnder modulator in a generic indium phosphide platform. We calculate the frequency response of the modulator for a range of mask design parameters. We propose the design parameters for a 50Ω, velocity matched MZM with 95GHz bandwidth

    Defining constipation to estimate its prevalence in the community: Results from a national survey

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    © 2019 The Author(s). Background: Different definitions of constipation have been used to estimate its prevalence in the community but this creates difficulties when comparing results from various studies. This study explores the impact of different definitions on prevalence estimates in the same population and compares the performance of simple definitions with the Rome III criteria. Methods: The prevalence of constipation in a large nationally representative sample of community-dwelling adults was estimated using five simple definitions of constipation and compared with definitions based on the Rome III criteria. The sensitivity, specificity, and positive and negative predictive values, were calculated for each definition using the Rome III criteria as the gold standards for chronic and sub-chronic constipation. Results: Prevalence estimates for the five simple definitions ranged from 9.4 to 58.9%, while the prevalence estimates using the Rome III criteria were 24.0% (95%CI: 22.1, 25.9) for chronic constipation and 39.6% (95%CI: 37.5, 41.7) for sub-chronic constipation. None of the simple definitions were adequate compared to the Rome III criteria. Self-reported constipation over the past 12 months had the highest sensitivity (91.1%, 95%CI: 88.8, 93.4) and negative predictive value (94.5%, 95%CI: 93.1, 96.1) compared to the Rome III criteria for chronic constipation but an unacceptably low specificity (51.3%, 95%CI: 48.8, 53.8) and positive predictive value (37.1%, 95%CI: 34.4, 39.9). Conclusions: The definition used to identify constipation within a population has a considerable impact on the prevalence estimate obtained. Simple definitions, commonly used in research, performed poorly compared with the Rome III criteria. Studies estimating population prevalence of constipation should use definitions based on the Rome criteria where possible

    Orbital Elements of Comet C/1490 Y1 and the Quadrantid shower

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    The Quadrantid shower, one of the most intense showers, has been observed at the beginning of January each year. However, the origin of the meteors is still unknown. It was Hasegawa (1979) who first suggested comet C/1490 Y1 to be the likely origin of the shower based on the historical records of East Asia. We analyse the records of Jo-Seon-Wang-Jo-Sil-Lok (the Annals of the Joseon Dynasty in ancient Korea) and calculate the preliminary orbital elements of comet C/1490 Y1 using a modified Gauss method. We find that comet C/1490 Y1 was a periodic one and its orbital path was very similar to that of the Quadrantid meteor stream. The determined orbital elements are perifocal passage time Tp=2265652.2983 days (7.8 Jan. 1491 in UT), perifocal distance q=0.769 AU, eccentricity e=0.747, semimajor axis a=3.04 AU, argument of the perifocus omega=164.03 degrees, longitude of ascending node Omega=283.00 degrees, and inclination i=70.22 degrees for the epoch of J2000.0. We, therefore, conclude that our result verifies the suggestion that the comet C/1490 Y1 is the origin of the Quandrantid meteor shower, but was a periodic comet. We dicuss a possible link between this comet and the asteroid 2003 EH1 as well.Comment: 7 pages, 2 figures, accepted for publication in MNRA

    Health care providers' judgments in chronic pain: the influence of gender and trustworthiness

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    Estimates of patients' pain, and judgments of their pain expression, are affected by characteristics of the observer and of the patient. In this study, we investigated the impact of high or low trustworthiness, a rapid and automatic decision made about another, and of gender and depression history on judgments made by pain clinicians and by medical students. Judges viewed a video of a patient in pain presented with a brief history and rated his or her pain, and the likelihood that it was being exaggerated, minimized, or hidden. Judges also recommended various medical and treatment options. Contrary to expectations, trustworthiness had no main effect on pain estimates or judgments, but interacted with gender producing pervasive bias. Women, particularly those rated of low trustworthiness, were estimated to have less pain and to be more likely to exaggerate it. Unexpectedly, judgments of exaggeration and pain estimates were independent. Consistent with those judgments, men were more likely to be recommended analgesics, and women to be recommended psychological treatment. Effects of depression history were inconsistent and hard to interpret. Contrary to expectations, clinicians' pain estimates were higher than medical students', and indicated less scepticism. Empathy was unrelated to these judgments. Trustworthiness merits further exploration in healthcare providers' judgments of pain authenticity and how it interacts with other characteristics of patients. Furthermore, systematic disadvantage to women showing pain is of serious concern in healthcare settings
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