4,540 research outputs found

    The topological susceptibility in finite temperature QCD and axion cosmology

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    We study the topological susceptibility in 2+1 flavor QCD above the chiral crossover transition temperature using Highly Improved Staggered Quark action and several lattice spacings, corresponding to temporal extent of the lattice, Nτ=6,8,10N_\tau=6,8,10 and 1212. We observe very distinct temperature dependences of the topological susceptibility in the ranges above and below 250250 MeV. While for temperatures above 250250 MeV, the dependence is found to be consistent with dilute instanton gas approximation, at lower temperatures the fall-off of topological susceptibility is milder. We discuss the consequence of our results for cosmology wherein we estimate the bounds on the axion decay constant and the oscillation temperature if indeed the QCD axion is a possible dark matter candidate.Comment: 19 pages and 7 figures; v2: A new figure, a few references and minor comments added; published versio

    Carotid Endarterectomy During Index Hospital Admission for Patients With Acute Mild to Moderate Stroke

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    Objective: The timing of carotid endarterectomy (CEA) after acute stroke due to an infarct in themiddle cerebral artery territory with ipsilateral internal carotid artery stenosis remains controversial. We evaluated the results of CEA in this group of patients during the index hospital admission. Methods: We performed a retrospective review of all patients admitted with acute, mild (National Institutes of Health [NIH] stroke scale score, 1-5) and moderate stroke (NIH stroke scale score, 6-14) in the distribution of the middle cerebral artery with $70% ipsilateral internal carotid artery stenosis admitted to two midsize teaching hospitals with stroke certification from 2005 to 2020. Patients with focal transient ischemic attacks were excluded. An indwelling shunt was placed if the patient developed a new neurologic deficit with carotid cross-clamping or ischemic electroencephalographic changes under general anesthesia. Results: A total of 74 patients (45 men) aged 35 to 87 years (mean age, 70.1 6 10.8 years). Of the 74 patients, 61 had a NIH stroke scale score of 1 to 5) and 13 an NIH stroke scale score of 6 to 14. Twelve patients were given intravenous tissue plasminogen activator. Of the 74 patients, 21 had undergone CEA 3 to 5 days after stroke and 53 had done so 6 to 8 days after stroke. Cervical block anesthesia was used for 54 patients (20 with general anesthesia), and a shunt was required for 15 patients (20%). Four patients (5.4%) had experienced severe postoperative stroke (three new ischemic infarcts and one intracerebral hemorrhage), resulting in death in all four. Two patients (2.7%) had developed postoperative seizures. Two patients (2.7%) had experienced temporary cranial nerve palsy (hypoglossal in one, ramus mandibularis in one). Conclusions: CEA for acute mild to moderate stroke can be performed with satisfactory results during the index admission. This strategy is useful to prevent recurrent stroke

    N-grams Based Supervised Machine Learning Model for Mobile Agent Platform Protection against Unknown Malicious Mobile Agents

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    From many past years, the detection of unknown malicious mobile agents before they invade the Mobile Agent Platform has been the subject of much challenging activity. The ever-growing threat of malicious agents calls for techniques for automated malicious agent detection. In this context, the machine learning (ML) methods are acknowledged more effective than the Signature-based and Behavior-based detection methods. Therefore, in this paper, the prime contribution has been made to detect the unknown malicious mobile agents based on n-gram features and supervised ML approach, which has not been done so far in the sphere of the Mobile Agents System (MAS) security. To carry out the study, the n-grams ranging from 3 to 9 are extracted from a dataset containing 40 malicious and 40 non-malicious mobile agents. Subsequently, the classification is performed using different classifiers. A nested 5-fold cross validation scheme is employed in order to avoid the biasing in the selection of optimal parameters of classifier. The observations of extensive experiments demonstrate that the work done in this paper is suitable for the task of unknown malicious mobile agent detection in a Mobile Agent Environment, and also adds the ML in the interest list of researchers dealing with MAS security

    A Study to Reconnoitering the dynamics of Talent Management Procedure at Hotels in Jharkhand

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    Talent is the product of capability (skills, education, training, and knowledge), attached with motivation (assignation, gratification, challenge, and well-being) and opportunity (H.G. van Dijk, October 2008). An integrated strategic approach to managing careers involves attracting, retaining, developing, and transitioning people within the organization (Valamis, 2021). The world of knowledge-intensive business considers human resources to be rare and unique. According to most experts, the sector of talent management does not have a clear sense of dimensions, terminology, and a theoretical framework. The goal of this study paper is to investigate and conclude how select hotels in Jharkhand handle and differentiate their staff management operations in terms of talent recruitment and retention. Hotels in Jharkhand use a range of approaches to evaluate the effectiveness of their actions and initiatives, including an overview of how they treat an employee and how they plan to continue to innovate to measure the success of their actions and projects? Additionally, their approach needs to be more inclusive. The findings would be significant for managers who recruit and manage employees, hoteliers, and higher education institutions dealing with the industry's skills gap

    A polyethylene glycol functionalized hyaluronic acid coating for cardiovascular catheter lubrication

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    Catheterization is a common medical operation for cardiovascular disease diagnosis and treatment, where low friction is attained through hydrophilic lubricious coatings. But these coatings can cause iatrogenic complications when particles become lose and float freely in the blood stream. Here we present an ultra-thin coating based on polyethylene glycol (PEG) functionalized hyaluronic acid (HA). The mussel-inspired biopolymer hyaluronic acid was first conjugated to dopamine (DN) to get HADN and then poly (ethylene glycol) bis (3-amino-propyl) terminated (PBA) was used to functionalize the HADN with PEG. The reciprocating sliding ball-on-flat ex vivo model based on PU ball and porcine aorta was used to evaluate the lubrication performance and the results suggest coating of HADN with best lubrication enhancement. After 40 min friction test, the surface of aorta remained intact for HADN-PBA coated PU as compared to HADN coating and positive control (sliding against bare PU). The amount of glycocalyx, number of endothelial nuclei and intima surface of aorta for coated PU were similar to negative control (without rubbing). Besides lubrication, the high biocompatibility suggests the coating of HADN-PBA is safe and lubrication benefits to the cardiovascular catheter. (c) 2020 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/)

    Direct Detection of Products from the Pyrolysis of 2-Phenethyl Phenyl Ether

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    The pyrolysis of 2-phenethyl phenyl ether (PPE, C_6H_5C_2H_4OC_6H_5) in a hyperthermal nozzle (300-1350 °C) was studied to determine the importance of concerted and homolytic unimolecular decomposition pathways. Short residence times (<100 μs) and low concentrations in this reactor allowed the direct detection of the initial reaction products from thermolysis. Reactants, radicals, and most products were detected with photoionization (10.5 eV) time-of-flight mass spectrometry (PIMS). Detection of phenoxy radical, cyclopentadienyl radical, benzyl radical, and benzene suggest the formation of product by the homolytic scission of the C_6H_5C_2H_4-OC_6H_5 and C_6H_5CH_2-CH_2OC_6H_5 bonds. The detection of phenol and styrene suggests decomposition by a concerted reaction mechanism. Phenyl ethyl ether (PEE, C_6H_5OC_2H_5) pyrolysis was also studied using PIMS and using cryogenic matrix-isolated infrared spectroscopy (matrix-IR). The results for PEE also indicate the presence of both homolytic bond breaking and concerted decomposition reactions. Quantum mechanical calculations using CBS-QB3 were conducted, and the results were used with transition state theory (TST) to estimate the rate constants for the different reaction pathways. The results are consistent with the experimental measurements and suggest that the concerted retro-ene and Maccoll reactions are dominant at low temperatures (below 1000 °C), whereas the contribution of the C_6H_5C_2H_4-OC_6H_5 homolytic bond scission reaction increases at higher temperatures (above 1000 °C)

    Design of an optomagnonic crystal: towards optimal magnon-photon mode matching at the microscale

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    We put forward the concept of an optomagnonic crystal: a periodically patterned structure at the microscale based on a magnetic dielectric, which can co-localize magnon and photon modes. The co-localization in small volumes can result in large values of the photon-magnon coupling at the single quanta level, which opens perspectives for quantum information processing and quantum conversion schemes with these systems. We study theoretically a simple geometry consisting of a one-dimensional array of holes with an abrupt defect, considering the ferrimagnet Yttrium Iron Garnet (YIG) as the basis material. We show that both magnon and photon modes can be localized at the defect, and use symmetry arguments to select an optimal pair of modes in order to maximize the coupling. We show that an optomagnonic coupling in the kHz range is achievable in this geometry, and discuss possible optimization routes in order to improve both coupling strengths and optical losses.Comment: 18 pages, 11 figure

    An ex vivo salivary lubrication system to mimic xerostomic conditions and to predict the lubricating properties of xerostomia relieving agents

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    Advances in medical research has resulted in successful treatment of many life-threatening infectious diseases as well as autoimmune and lifestyle-related diseases, increasing life-expectancy of both the developed and developing world. As a result of a growing ageing population, the focus has also turned on chronic diseases which seriously affect the quality of older patient life. Xerostomia (dry mouth) is one such condition, which leads to bad oral health and difficulty in consumption of dry foods and speech. Saliva substitutes are used to ease symptoms. However, they often don't work properly and objective comparison of saliva substitutes to mimic natural salivary functions does not exist. The study thus aims to develop an ex vivo friction assay simulating dry mouth conditions and facilitating objective comparison of saliva substitutes. A reciprocating sliding tongue-enamel system was developed and compared to a PDMS (polydimethylsiloxane)-PDMS friction system. The tongue-enamel system, but not the PDMS-PDMS model, showed high mucin-containing saliva (unstimulated and submandibular/sublingual saliva) to give higher Relief than mucin-poor lubricants (water, parotid saliva, Dentaid Xeros) and correlated well (r = 0.97) with in vivo mouth feel. The tongue-enamel friction system mimicked dry mouth conditions and relief and seems suited to test agents meant to lubricate desiccated oral surfaces
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