7,406 research outputs found
Cassini detection of Enceladus' cold water-group plume ionosphere
This study reports direct detection by the Cassini plasma spectrometer of freshly-produced water-group ions (O+, OH+, H2O+, H3O+) and heavier water dimer ions (HxO(2))(+) very close to Enceladus where the plasma begins to emerge from the plume. The data were obtained during two close ( 52 and 25 km) flybys of Enceladus in 2008 and are similar to ion data in cometary comas. The ions are observed in detectors looking in the Cassini ram direction exhibiting energies consistent with the Cassini speed, indicative of a nearly stagnant plasma flow in the plume. North of Enceladus the plasma slowing commences about 4 to 6 Enceladus radii away, while south of Enceladus signatures of the plasma interaction with the plume are detected 22 Enceladus radii away. Citation: Tokar, R. L., R. E. Johnson, M. F. Thomsen, R. J. Wilson, D. T. Young, F. J. Crary, A. J. Coates, G. H. Jones, and C. S. Paty ( 2009), Cassini detection of Enceladus' cold water-group plume ionosphere, Geophys. Res. Lett., 36, L13203, doi:10.1029/2009GL038923
Upper gastrointestinal diseases in patients for endoscopy in South-Western Uganda
Background: There is a paucity of published data regarding upper gastrointestinal diseases in Ugandans with upper gastrointestinal symptoms referred for endoscopy.Objectives: To study the presenting complaints, pathology and Helicobacter pylori prevalence among patients with upper gastrointestinal symptoms in South-Western Uganda.Methods: Patients presenting with upper gastrointestinal symptoms underwent upper endoscopy and a urease test for Helicobacter Pylori, all suspicious lesions were biopsied for histopathology review as appropriate.Results: The most common presenting complaints were epigastric pain (51.6%), dysphagia (13.6%) and odynophagia (7.1%). The most common endoscopy finding was gastritis (40.2%), followed by normal examination (15.2%), oesophageal cancer (13.6%), gastric ulcer (7.6%) and gastric cancer (7.1%). Patients older than 40 years (n=110) had significant findings including gastritis (50.9%), oesophageal cancer (22.7%) and gastric cancer (11.8%). However in younger patients, with the age range of 18-40 years (n=74), most examinations were normal (92.9%). Of the 176 patients able to undergo Helicobacter pylori testing 75.6% were positive. Helicobacter pylori infection was associated with statistically significant increase in gastritis, oesophageal cancer, gastric ulcer, gastric cancer, and duodenal ulcers (p-values< 0.05).Conclusion: Gastritis, ulcerative disease, and upper gastrointestinal malignancies are common in South-Western Ugandansand are associated with a high prevalence of Helicobacter pylori. Keywords: Upper gastrointestinal symptoms, Pathology, Urease test, Helicobacter pylori, Endoscopy, Uganda
Neutrophil and Monocyte Bactericidal Responses to 10 Weeks of Low-Volume High-Intensity Interval or Moderate-Intensity Continuous Training in Sedentary Adults.
Neutrophils and monocytes are key components of the innate immune system that undergo age-associated declines in function. This study compared the impact of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on immune function in sedentary adults. Twenty-seven (43 ± 11 years) healthy sedentary adults were randomized into ten weeks of either a HIIT (>90% maximum heart rate) or MICT (70% maximum heart rate) group training program. Aerobic capacity (VO2peak), neutrophil and monocyte bacterial phagocytosis and oxidative burst, cell surface receptor expression, and systemic inflammation were measured before and after the training. Total exercise time commitment was 57% less for HIIT compared to that for MICT while both significantly improved VO2peak similarly. Neutrophil phagocytosis and oxidative burst and monocyte phagocytosis and percentage of monocytes producing an oxidative burst were improved by training similarly in both groups. Expression of monocyte but not neutrophil CD16, TLR2, and TLR4 was reduced by training similarly in both groups. No differences in systemic inflammation were observed for training; however, leptin was reduced in the MICT group only. With similar immune-enhancing effects for HIIT compared to those for MICT at 50% of the time commitment, our results support HIIT as a time efficient exercise option to improve neutrophil and monocyte function
Heat and fluid flow in a scraped-surface heat exchanger containing a fluid with temperature-dependent viscosity
Scraped-surface heat exchangers (SSHEs) are extensively used in a wide variety of industrial settings where the continuous processing of fluids and fluid-like materials is involved. The steady non-isothermal flow of a Newtonian fluid with temperature-dependent viscosity in a narrow-gap SSHE when a constant temperature difference is imposed across the gap between the rotor and the stator is investigated. The mathematical model is formulated and the exact analytical solutions for the heat and fluid flow of a fluid with a general dependence of viscosity on temperature for a general blade shape are obtained. These solutions are then presented for the specific case of an exponential dependence of viscosity on temperature. Asymptotic methods are employed to investigate the behaviour of the solutions in several special limiting geometries and in the limits of weak and strong thermoviscosity. In particular, in the limit of strong thermoviscosity (i.e., strong heating or cooling and/or strong dependence of viscosity on temperature) the transverse and axial velocities become uniform in the bulk of the flow with boundary layers forming either just below the blade and just below the stationary upper wall or just above the blade and just above the moving lower wall. Results are presented for the most realistic case of a linear blade which illustrate the effect of varying the thermoviscosity of the fluid and the geometry of the SSHE on the flow
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G-Protein coupled receptors: structure and function in drug discovery
The G-protein coupled receptors (GPCRs) superfamily comprise similar proteins arranged into families or classes thus making it one of the largest in the mammalian genome. GPCRs take part in many vital physiological functions making them targets for numerous novel drugs. GPCRs share some distinctive features, such as the seven transmembrane domains, they also differ in the number of conserved residues in their transmembrane domain. Here we provide an introductory and accessible review detailing the computational advances in GPCR pharmacology and drug discovery. An overview is provided on family A-C GPCRs; their structural differences, GPCR signalling, allosteric binding and cooperativity. The dielectric constant (relative permittivity) of proteins is also discussed in the context of site-specific environmental effects
Reduction of circulating cholesterol and apolipoprotein levels during sepsis
Sepsis with multiple organ failure is frequently associated with a substantial decrease of cholesterol levels. This decrease of cholesterol is strongly associated with mortality suggesting a direct relation between inflammatory conditions and altered cholesterol homeostasis. The host response during sepsis is mediated by cytokines and growth factors, which are capable of influencing lipid metabolism. Conversely lipoproteins are also capable of modulating cytokine production during the inflammatory response. Therefore the decrease in circulating cholesterol levels seems to play a crucial role in the pathophysiology of sepsis. In this review the interaction between cytokines and lipid metabolism and its clinical consequences will be discussed
Development and initial validation of the bronchiectasis exacerbation and symptom tool (BEST)
BACKGROUND:
Recurrent bronchiectasis exacerbations are related to deterioration of lung function, progression of the disease, impairment of quality of life, and to an increased mortality. Improved detection of exacerbations has been accomplished in chronic obstructive pulmonary disease through the use of patient completed diaries. These tools may enhance exacerbation reporting and identification. The aim of this study was to develop a novel symptom diary for bronchiectasis symptom burden and detection of exacerbations, named the BEST diary.
METHODS:
Prospective observational study of patients with bronchiectasis conducted at Ninewells Hospital, Dundee. We included patients with confirmed bronchiectasis by computed tomography, who were symptomatic and had at least 1 documented exacerbation of bronchiectasis in the previous 12\u2009months to participate. Symptoms were recorded daily in a diary incorporating cough, sputum volume, sputum colour, dyspnoea, fatigue and systemic disturbance scored from 0 to 26.
RESULTS:
Twenty-one patients were included in the study. We identified 29 reported (treated exacerbations) and 23 unreported (untreated) exacerbations over 6-month follow-up. The BEST diary score showed a good correlation with the established and validated questionnaires and measures of health status (COPD Assessment Test, r =\u20090.61, p =\u20090.0037, Leicester Cough Questionnaire, r =\u2009-\u20090.52,p =\u20090.0015, St Georges Respiratory Questionnaire, r =\u20090.61,p <\u20090.0001 and 6\u2009min walk test, r =\u2009-\u20090.46,p =\u20090.037). The mean BEST score at baseline was 7.1 points (SD 2.2). The peak symptom score during exacerbation was a mean of 16.4 (3.1), and the change from baseline to exacerbation was a mean of 9.1 points (SD 2.5). Mean duration of exacerbations based on time for a return to baseline symptoms was 15.3\u2009days (SD 5.7). A minimum clinically important difference of 4 points is proposed.
CONCLUSIONS:
The BEST symptom diary has shown concurrent validity with current health questionnaires and is responsive at onset and recovery from exacerbation. The BEST diary may be useful to detect and characterise exacerbations in bronchiectasis clinical trials
A photometric monitoring of bright high-amplitude delta Scuti stars. II. Period updates for seven stars
We present new photometric data for seven high-amplitude delta Scuti stars.
The observations were acquired between 1996 and 2002, mostly in the Johnson
photometric system. For one star (GW UMa), our observations are the first since
the discovery of its pulsational nature from the Hipparcos data.The primary
goal of this project was to update our knowledge on the period variations of
the target stars. For this, we have collected all available photometric
observations from the literature and constructed decades-long O-C diagrams of
the stars. This traditional method is useful because of the single-periodic
nature of the light variations. Text-book examples of slow period evolution (XX
Cyg, DY Her, DY Peg) and cyclic period changes due to light-time effect (LITE)
in a binary system (SZ Lyn) are updated with the new observations. For YZ Boo,
we find a period decrease instead of increase. The previously suggested
LITE-solution of BE Lyn (Kiss & Szatmary 1995) is not supported with the new
O-C diagram. Instead of that, we suspect the presence of transient light curve
shape variations mimicking small period changes.Comment: 11 pages, 15 figures, accepted for publication in A&
Living Machines: A study of atypical animacy
This paper proposes a new approach to animacy detection, the task of determining whether an entity is represented as animate in a text. In particular, this work is focused on atypical animacy and examines the scenario in which typically inanimate objects, specifically machines, are given animate attributes. To address it, we have created the first dataset for atypical animacy detection, based on nineteenth-century sentences in English, with machines represented as either animate or inanimate. Our method builds on recent innovations in language modeling, specifically BERT contextualized word embeddings, to better capture fine-grained contextual properties of words. We present a fully unsupervised pipeline, which can be easily adapted to different contexts, and report its performance on an established animacy dataset and our newly introduced resource. We show that our method provides a substantially more accurate characterization of atypical animacy, especially when applied to highly complex forms of language use
A transcriptome-driven analysis of epithelial brushings and bronchial biopsies to define asthma phenotypes in U-BIOPRED
RATIONALE AND OBJECTIVES: Asthma is a heterogeneous disease driven by diverse immunologic and inflammatory mechanisms. We used transcriptomic profiling of airway tissues to help define asthma phenotypes. METHODS: The transcriptome from bronchial biopsies and epithelial brushings of 107 moderate-to-severe asthmatics were annotated by gene-set variation analysis (GSVA) using 42 gene-signatures relevant to asthma, inflammation and immune function. Topological data analysis (TDA) of clinical and histological data was used to derive clusters and the nearest shrunken centroid algorithm used for signature refinement. RESULTS: 9 GSVA signatures expressed in bronchial biopsies and airway epithelial brushings distinguished two distinct asthma subtypes associated with high expression of T-helper type 2 (Th-2) cytokines and lack of corticosteroid response (Group 1 and Group 3). Group 1 had the highest submucosal eosinophils, high exhaled nitric oxide (FeNO) levels, exacerbation rates and oral corticosteroid (OCS) use whilst Group 3 patients showed the highest levels of sputum eosinophils and had a high BMI. In contrast, Group 2 and Group 4 patients had an 86% and 64% probability of having non-eosinophilic inflammation. Using machine-learning tools, we describe an inference scheme using the currently-available inflammatory biomarkers sputum eosinophilia and exhaled nitric oxide levels along with OCS use that could predict the subtypes of gene expression within bronchial biopsies and epithelial cells with good sensitivity and specificity. CONCLUSION: This analysis demonstrates the usefulness of a transcriptomic-driven approach to phenotyping that segments patients who may benefit the most from specific agents that target Th2-mediated inflammation and/or corticosteroid insensitivity
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