2,557 research outputs found

    Long-term record of aerosol optical properties and chemical composition from a high-altitude site (Manora Peak) in Central Himalaya

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    A long-term study, conducted from February 2005 to July 2008, involving chemical composition and optical properties of ambient aerosols from a high-altitude site (Manora Peak: 29.4°N, 79.5°E, ~1950ma.s.l.) in the central Himalaya is reported here. The total suspended particulate (TSP) mass concentration varied from 13 to 272 µgm.3 over a span of 42 months. Aerosol optical depth (AOD) and TSP increase significantly during the summer (April-June) due to increase in the concentration of mineral dust associated with the long-range transport from desert regions (from the middle-East and Thar Desert in western India). The seasonal variability in the carbonaceous species (EC, OC) is also significantly pronounced, with lower concentrations during the summer and monsoon (July-August) and relatively high during the post-monsoon (September-November) and winter (December-March). On average, total carbonaceous aerosols (TCA) and water-soluble inorganic species (WSIS) contribute nearly 25 and 10% of the TSP mass, respectively. The WSOC/OC ratios range from 0.36 to 0.83 (average: 0.55±0.15), compared to lower ratios in the Indo-Gangetic Plain (range: 0.35-0.40), and provide evidence for the enhanced contribution from secondary organic aerosols. The mass fraction of absorbing EC ranged from less than a percent (during the summer) to as high as 7.6% (during the winter) and absorption coefficient (babs, at 678 nm) varied between 0.9 to 33.9Mm-1 (1Mm-1=10-6 m-1). A significant linear relationship between babs and EC (µgCm-3) yields a slope of 12.2 (±2.3) m2 g-1, which is used as a measure of the mass absorption efficiency (σabs) of EC

    Diamond pixel detector for beam profile monitoring in COMET experiment at J-PARC

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    We present the design and initial prototype results of a pixellized proton beam profile monitor for the COMET experiment at J-PARC. The goal of COMET is to look for charged lepton flavor violation by direct muon to electron conversion at a sensitivity of 0−190^{-19}. An 8 GeV proton beam pulsed at 100 ns with 101010^{10} protons/s will be used to create muons through pion production and decay. In the final experiment, the proton flux will be raised to 101410^{14} protons/sec to increase the sensitivity. These requirements of harsh radiation tolerance and fast readout make diamond a good choice for constructing a beam profile monitor in COMET. We present first results of the characterization of single crystal diamond (scCVD) sourced from a new company, 2a systems Singapore. Our measurements indicate excellent charge collection efficiency and high carrier mobility down to cryogenic temperatures.Comment: Pixel 2014 Workshop proceedings in JINS

    Patient-Specific Patellofemoral Arthroplasty

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    Mine-Rescue Stations in Kuzbass in 1922–1934

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    In the early 1920s, Russia moved on from the New Economic Policy to industrialization. The Kuznetsk Coal Basin needed an advanced mine-rescue system to support its growing coal industry. This research focused on the chain of decisions made by the state authorities to expand the mine-rescue stations network across the USSR. The authors used the examples of mine-rescue stations in Anzhero-Sudzhensk, Leninskiy, and Kemerovo to describe the formation and development of respiratory and supporting rescue teams. Archival sources made it possible to restore the quantitative composition, wage system, and funding sources of the Kuzbass mine-rescue service in July 1, 1924, as well as to identify the first management team. The mine-rescue development followed the expansion of the coal industry under the efficient state control provided by the centralized mining supervision. By the beginning of the second five-year industrial plan, Kuzbass was responsible for 8.5 % of the total mine-rescue stations in the country. The Kuzbass region owed its wide and efficient network of mine-rescue stations to the financial and organizational support of the state

    Early identification of haemodynamic response to pharmacotherapy is essential for primary prophylaxis of variceal bleeding in patients with 'high-risk' varices

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    Background: A beta-blocker is recommended for primary prophylaxis of variceal bleeding; however, only one-third have hepatic venous pressure gradient (HVPG) response. The role of addition of isosorbide-5-mononitrate (ISMN) to beta-blocker and benefits of HVPG-guided 'a la carte' approach remain unclear. Aim: To determine the benefits of HVPG-guided pharmacotherapy in primary prophylaxis of variceal bleeding using beta-blocker and ISMN. Patients and methods: Consecutive patients of cirrhosis, with high-risk varices, with no previous variceal bleeding were included. After baseline HVPG, patients received incremental propranolol to achieve HR of 55/min. After one-month, HVPG was repeated to determine response (<12 mmHg or ≥20% reduction). ISMN was added in nonresponders and HVPG repeated. Patients were followed up for 24 months. Results: Of 56 patients (age 47 ± 13, males 79%) from 89 eligible patients, 21 (38%) responded to beta-blocker alone. Six additional patients responded to combination. Thus, overall 48% (27/56) patients responded. Variceal bleeding occurred in seven of 56 (13%) patients [one of 27 (4%) responder, five of 23 (22%) nonresponders and one of six (17%) with unknown response; P = N.S.]. The actuarial probability of variceal bleeding at median 24 months was 4% in responders and 22% in nonresponders (P < 0.05). Ten (18%) patients developed adverse effects to propranolol and six of 35 (17%) to nitrates requiring dose reduction. Risk factors of variceal bleed were grade IV varices and haemodynamic nonresponse. Conclusions: For primary prophylaxis, a beta-blocker is effective in 38% and addition of ISMN raises the response rate to about half of patients. The HVPG-guided 'a la carte' approach may be considered for these patients

    Mergers of double neutron stars with one high-spin component: brighter kilonovae and fallback accretion, weaker gravitational waves

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    Neutron star mergers where both stars have negligible spins are commonly considered as the most likely, "standard" case. But based on observed systems, we estimate that actually a non-negligible fraction of all double neutron star mergers (∼\sim 5 %) may contain one millisecond component. We use the Lagrangian Numerical Relativity code SPHINCS_BSSN to simulate mergers where one star has no spin and the other has a dimensionless spin parameter of χ=0.5\chi=0.5. These mergers exhibit several distinct signatures compared to irrotational cases. Morphologically, they are similar to unequal mass mergers and they form in particular only one, very pronounced spiral arm. Compared to the non-spinning cases, they dynamically eject an order of magnitude more mass of unshocked material at the original low electron fraction of the neutron stars and therefore produce particularly bright, red kilonovae and brighter kilonova afterglows months after the merger. We also find that the spinning cases have significantly more fallback accretion, with implications for late-time X-ray flares and the duration of the associated gamma-ray burst. Overall, the spinning case collisions are substantially less violent and they emit smaller amounts of shock-generated semi-relativistic material and therefore produce less pronounced blue/UV kilonova precursor signals. Their post-merger gravitational wave signal is weaker and, during the simulated time, substantially smaller amounts of energy and angular momentum are emitted. Therefore the central remnant contains a larger angular momentum reservoir and could remain an "active engine" for a longer time.Comment: 17 pages, 15 figures, submitte

    Revealed Likelihood and Knightian Uncertainty.

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    Abstract Nonadditive expected utility models were developed for explaining preferences in settings where probabilities cannot be assigned to events. In the absence of probabilities, difficulties arise in the interpretation of likelihoods of events. In this paper we introduce a notion of revealed likelihood that is defined entirely in terms of preferences and that does not require the existence of (subjective) probabilities. Our proposal is that decision weights rather than capacities are more suitable measures of revealed likelihood in rank-dependent expected utility models and prospect theory. Applications of our proposal to the updating of beliefs and to the description of attitudes towards ambiguity are presented

    Analysis of cerebrospinal fluid adenosine deaminase level in tuberculous meningitis and validation of sensitivity and specificity

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    Background: Tuberculous meningitis is an important cause of morbidity and mortality in developing countries especially in India. The mortality associated with tuberculous meningitis is very high if not detected early and meticulous treatment is not given. CSF analysis and imaging are the most commonly used tools for diagnosis of meningitis. But these are often inadequate in making a definitive diagnosis. CSF Adenosine Deaminase estimation (ADA) is useful in differentiation of tuberculous meningitis from non-tuberculous meningitis. Though few studies have proved efficacy of Adenosine Deaminase level for the diagnosis, studies to assess the sensitivity and specificity of ADA levels were limited. This study was conducted to assess its usefulness and to validate the sensitivity and specificity of ADA level in tuberculous meningitis (TBM).Methods: This was a prospective study conducted at Academy of Medical Sciences, Pariyaram for a period of 18 months from December 2013 to June 2015, Adenosine deaminase level was studied in the cerebrospinal fluid of 50 patients who got admitted with symptoms and signs of meningitis in the medical wards and intensive care units who fulfilled the inclusion criteria.Results: In this study 50 patients were diagnosed clinically and with CSF analysis as meningitis. The mean cerebrospinal fluid adenosine deaminase activity was 23.08+17.5in Tuberculous meningitis 3.8 +1.92U/l in Bacterial meningitis and 4.8+2.3U/l in Viral meningitis. The adenosine deaminase activity in Tuberculous meningitis cases were significantly higher than non-tuberculous meningitis. The sensitivity and specificity of this test for diagnosis of tuberculous meningitis was 90% and 100% respectively with ADA value of more than 10U/L.Conclusions: This study found out that estimation of CSF Adenosine level is a very useful test for the diagnosis of tuberculous meningitis. The sensitivity and specificity attained in this study were comparable to other studies. This study also found out that ADA estimation is very useful in distinguishing tuberculous and viral meningitis

    Histological subclassification of cirrhosis based on histological-haemodynamic correlation

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    Background: Determining a relationship between specific histological parameters in cirrhosis and hepatic venous pressure gradient can be used to subclassify cirrhosis. Aim: To determine the relationship between hepatic venous pressure gradient and specific histological parameters in cirrhosis. Methods: Forty-seven patients (mean age: 46.2 ± 13.6 years; 36 male) with biopsy-proven cirrhosis and hepatic venous pressure gradient measurements within 1 month of biopsy were studied. The following histological parameters were scored semiquantitatively: nodule size, loss of portal tracts and central veins, portal inflammation, periportal inflammation, bile duct proliferation, lobular inflammation, ballooning, fatty change, cholestasis and septal thickness. Results: On multiple ordinal regression analysis, small nodule size (odds ratio: 21.0; 95% confidence interval: 2.1-208.2, P = 0.009) and thick septa (OR: 42.6; CI: 2.3-783.7, P = 0.011) were significantly associated with the presence of clinically significant portal hypertension. A score was assigned to each of the two parameters (nodule size: large = 1, medium = 2, small = 3 and septal thickness: thin = 1, medium = 2, thick = 3). Two subcategories were devised based on the composite score: category A (n = 12): score 1-3 and category B (n = 35): score 4-6. On ordinal regression, subcategory B (OR: 15.5; CI: 3.3-74.2, P = 0.001) was significantly associated with clinically significant portal hypertension. Conclusion: Small nodularity and thick septa are independent predictors of the presence of clinically significant portal hypertension
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