821 research outputs found

    Minimal Uncertainty in Momentum: The Effects of IR Gravity on Quantum Mechanics

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    The effects of the IR aspects of gravity on quantum mechanics is investigated. At large distances where due to gravity the space-time is curved, there appears nonzero minimal uncertainty Δp0\Delta p_{0} in the momentum of a quantum mechanical particle. We apply the minimal uncertainty momentum to some quantum mechanical interferometry examples and show that the phase shift depends on the area surrounded by the path of the test particle . We also put some limits on the related parameters. This prediction may be tested through future experiments. The assumption of minimal uncertainty in momentum can also explain the anomalous excess of the mass of the Cooper pair in a rotating thin superconductor ring.Comment: 8 pages, revised version accepted by PR

    Optimal Control of HIV Dynamic Using Embedding Method

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    This present study proposes an optimal control problem, with the final goal of implementing an optimal treatment protocol which could maximize the survival time of patients and minimize the cost of drug utilizing a system of ordinary differential equations which describes the interaction of the immune system with the human immunodeficiency virus (HIV). Optimal control problem transfers into a modified problem in measure space using an embedding method in which the existence of optimal solution is guaranteed by compactness of the space. Then the metamorphosed problem is approximated by a linear programming (LP) problem, and by solving this LP problem a suboptimal piecewise constant control function, which is more practical from the clinical viewpoint, is achieved. The comparison between the immune system dynamics in treated and untreated patients is introduced. Finally, the relationships between the healthy cells and virus are shown

    Impairment of perceptual closure in autism for vertex- but not edge-defined object images

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    One of the characteristics of autism spectrum disorder (ASD) is atypical sensory processing and perceptual integration. Here, we used an object naming task to test the significance of deletion of vertices versus extended contours (edges) in naming fragmented line drawings of natural objects in typically developing and ASD children. The basic components of a fragmented image in perceptual closure need to be integrated to make a coherent visual perception. When vertices were missing and only edges were visible, typically developing and ASD subjects performed similarly. But typically developing children performed significantly better than ASD children when only vertex information was visible. These results indicate impairment of binding vertices but not edges to form a holistic representation of an object in children with ASD

    A survey of patient safety culture: A tool for improving patient safety in healthcare providers service organizations

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    Background and aims: Patient safety is one of the main factors in quality of services provided by a health system. Patient safety culture plays a key role in improvement of patient safety, reduction of medical errors, and prevention of adverse events in health care organizations. Thereby, the present study is aimed to survey patient safety culture in hospitals of Neyshabur University of Medical Sciences. Methods: This research was a cross sectional study that conducted on all qualified staff of hospitals affiliated with Neyshabur University of Medical Sciences in 2013. Hospital Survey of Patient Safety Culture (HSOPSC) questionnaire was used to assess patient safety culture. The collected data were analyzed in SPSS (16), using Chi-Square test and logistic regression model. Results: Total score average of patient safety culture was 25.50±9.52. The results showed that among the twelve dimensions the highest and lowest scores were obtained by the supervisor/ manager expectations & actions promoting patient safety (score rate 45) and the reporting frequency of adverse events (score rate 15) respectively According to logistic regression model there was also significant relationship between the patient safety culture and direct contact with the patient, employment duration in hospital, and current unit (p<0.05). Conclusion: Total average of patient safety culture and scores of all twelve dimensions were lower than the acceptable criteria. Patient safety culture in the studied hospitals urgently needs enhancement and improvement. So, creating policies to institutionalize and enhance patient safety culture among the staffs are recommended

    Investigation on the Essential Oils of the Achillea Species: From Chemical Analysis to the In Silico Uptake against SARS-CoV-2 Main Protease

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    In this study, phytochemicals extracted from three different Achillea genera were identified and analyzed to be screened for their interactions with the SARS-CoV-2 main protease. In particular, the antiviral potential of these natural products against the SARS-CoV-2 main protease was investigated, as was their effectiveness against the SARS-CoV-1 main protease as a standard (due to its high similarity with SARS-CoV-2). These enzymes play key roles in the proliferation of viral strains in the human cytological domain. GC-MS analysis was used to identify the essential oils of the Achillea species. Chemi-informatics tools, such as AutoDock 4.2.6, SwissADME, ProTox-II, and LigPlot, were used to investigate the action of the pharmacoactive compounds against the main proteases of SARS-CoV-1 and SARS-CoV-2. Based on the binding energies of kessanyl acetate, chavibetol (m-eugenol), farnesol, and 7-epi-beta-eudesmol were localized at the active site of the coronaviruses. Furthermore, these molecules, through hydrogen bonding with the amino acid residues of the active sites of viral proteins, were found to block the progression of SARS-CoV-2. Screening and computer analysis provided us with the opportunity to consider these molecules for further preclinical studies. Furthermore, considering their low toxicity, the data may pave the way for new in vitro and in vivo research on these natural inhibitors of the main SARS-CoV-2 protease

    Analysis of geographical accessibility to rural health houses using the geospatial information system, a case study: Khuzestan Province, south-west Iran

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    Background: The use of rural health houses is one of the important approaches for delivering health services but, inappropriate infrastructures and limited resources make it difficult to design and implement plans to enhance and improve health services in rural areas. The aim of this study was to analyze the accessibility to rural health care services in the province of Khuzestan Materials and methods: This applied research was conducted in Khuzestan Province, south-west Iran with a cross-sectional approach in 2014. The population of the study was the villages and rural health houses. All the villages and rural health houses were included in the study without sampling. Descriptive data collected with a checklist from the Statistical Centre of Iran, IT Department of the Management Deputy of the Governor's Office and Ahvaz Jundishapur and Dezful University of Medical Sciences and spatial data obtained from the national Cartographic Center. The validity of the checklist was confirmed by 5 Public Health experts and 3 senior experts of the GIS system. Data analyzed with Arc GIS 9.3 software. Results: Khuzestan Province has 3461 villages with inhabitants. Based on the geographical distance to the nearest health house, 358 villages (10.34) with inhabitants were outside the service provision area with a distance of more than 6 In order to measure the total petroleum hydrocarbon available in the soil, first, 1 gr of the pot soil was taken and 10 ml dichloromethane solvent added to it, then the mixture was stirred for 5 minutes, and the resulting mixture was centrifuged for 5 minutes at a speed of 3000 rpm. After being centrifuged, 1 ml of the centrifuged solution was transferred to vials that were weighed before, and the dichloromethane was permitted to evaporate in the air for 48 hours. Afterwards, the vials were weighed again, and the removal percentage of the petroleum hydrocarbons was calculated based on the weight difference between the vials (21).km. Based on the population covered by health houses, 11 villages with more than 1000 population had inappropriate access to health houses. Conclusions: The results showed that geographical conditions and developmental infrastructures of the rural areas were some major challenges of access to health houses in Khuzestan Province, which requires the cooperation of several governmental sectors. Collection and storage of accurate, up-to-date, and complete information are very important steps in delivering primary healthcare services and enhancing the rural population health

    Statistical Mechanics of the Chinese Restaurant Process: lack of self-averaging, anomalous finite-size effects and condensation

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    The Pitman-Yor, or Chinese Restaurant Process, is a stochastic process that generates distributions following a power-law with exponents lower than two, as found in a numerous physical, biological, technological and social systems. We discuss its rich behavior with the tools and viewpoint of statistical mechanics. We show that this process invariably gives rise to a condensation, i.e. a distribution dominated by a finite number of classes. We also evaluate thoroughly the finite-size effects, finding that the lack of stationary state and self-averaging of the process creates realization-dependent cutoffs and behavior of the distributions with no equivalent in other statistical mechanical models.Comment: (5pages, 1 figure

    A novel approach of multimedia instruction applications in engineering education

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    Effective use of educational technology depends on knowledge of why and how to utilize technology to solve teaching and learning problems. The present study first conducts a systematic literature review of the limited studies undertaken on multimedia instruction applications for engineering education to critique the current status of knowledge in this area. The conventional qualitative content analysis method was employed for data analysis. The results highlighted the incompatibility of three basic educational elements i.e. engineering curriculum, educational resources and engineering students’ learning characteristics all of which posed major challenges in teaching and learning engineering courses. Multimedia instruction enhances engineering students’ understanding of engineering concepts, procedures, problems and solutions through direct visualization. Furthermore, it could indirectly assist students in achieving higher order learning levels and skills through enhancing or supporting educational resources and increasing students’ motivation. Mobile multimedia instruction and a student-generated multimedia learning approach to improve engineering education are suggested for future research. © 2005-2016 JATIT & LLS. All rights reserve

    A novel approach of multimedia instruction applications in engineering education

    Get PDF
    Effective use of educational technology depends on knowledge of why and how to utilize technology to solve teaching and learning problems. The present study first conducts a systematic literature review of the limited studies undertaken on multimedia instruction applications for engineering education to critique the current status of knowledge in this area. The conventional qualitative content analysis method was employed for data analysis. The results highlighted the incompatibility of three basic educational elements i.e. engineering curriculum, educational resources and engineering students’ learning characteristics all of which posed major challenges in teaching and learning engineering courses. Multimedia instruction enhances engineering students’ understanding of engineering concepts, procedures, problems and solutions through direct visualization. Furthermore, it could indirectly assist students in achieving higher order learning levels and skills through enhancing or supporting educational resources and increasing students’ motivation. Mobile multimedia instruction and a student-generated multimedia learning approach to improve engineering education are suggested for future research
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