Logarithmic Gradient Transformation and Chaos Expansion of Ito Processes

Since the seminal work of Wiener, the chaos expansion has evolved to a powerful methodology for studying a broad range of stochastic differential equations. Yet its complexity for systems subject to the white noise remains significant. The issue appears due to the fact that the random increments generated by the Brownian motion, result in a growing set of random variables with respect to which the process could be measured. In order to cope with this high dimensionality, we present a novel transformation of stochastic processes driven by the white noise. In particular, we show that under suitable assumptions, the diffusion arising from white noise can be cast into a logarithmic gradient induced by the measure of the process. Through this transformation, the resulting equation describes a stochastic process whose randomness depends only upon the initial condition. Therefore the stochasticity of the transformed system lives in the initial condition and thereby it can be treated conveniently with the chaos expansion tools

Fokker-Planck model for computational studies of monatomic rarefied gas flows

In this study, we propose a non-linear continuous stochastic velocity process for simulations of monatomic gas flows. The model equation is derived from a Fokker-Planck approximation of the Boltzmann equation. By introducing a cubic non-linear drift term, the model leads to the correct Prandtl number of 2/3 for monatomic gas, which is crucial to study heat transport phenomena. Moreover, a highly accurate scheme to evolve the computational particles in velocity- and physical space is devised. An important property of this integration scheme is that it ensures energy conservation and honours the tortuosity of particle trajectories. Especially in situations with small to moderate Knudsen numbers, this allows to proceed with much larger time steps than with direct simulation Monte Carlo (DSMC), i.e. the mean collision time not necessarily has to be resolved, and thus leads to more efficient simulations. Another computational advantage is that no direct collisions have to be calculated in the proposed algorithm. For validation, different micro-channel flow test cases in the near continuum and transitional regimes were considered. Detailed comparisons with DSMC for Knudsen numbers between 0.07 and 2 reveal that the new solution algorithm based on the Fokker-Planck approximation for the collision operator can accurately predict molecular stresses and heat flux and thus also gas velocity and temperature profiles. Moreover, for the Knudsen Paradox, it is shown that good agreement with DSMC is achieved up to a Knudsen number of about

Asymmetric Information in Iranian's Health Insurance Market: Testing of Adverse Selection and Moral Hazard

BACKGROUND: Asymmetric information is one of the most important issues in insurance market which occurred due to inherent characteristics of one of the agents involved in insurance contracts; hence its management requires designing appropriate policies. This phenomenon can lead to the failure of insurance market via its two consequences, namely, adverse selection and moral hazard. OBJECTIVE: This study was aimed to evaluate the status of asymmetric information in Iran's health insurance market with respect to the demand for outpatient services. MATERIALS/PATIENTS AND METHODS: This research is a cross sectional study conducted on households living in Iran. The data of the research was extracted from the information on household's budget survey collected by the Statistical Center of Iran in 2012. In this study, the Generalized Method of Moment model was used and the status of adverse selection and moral hazard was evaluated through calculating the latent health status of individuals in each insurance category. To analyze the data, Excel, Eviews and stata11 software were used. RESULTS: The estimation of parameters of the utility function of the demand for outpatient services (visit, medicine, and Para-clinical services) showed that households were more risk averse in the use of outpatient care than other goods and services. After estimating the health status of households based on their health insurance categories, the results showed that rural-insured people had the best health status and people with supplementary insurance had the worst health status. In addition, the comparison of the conditional distribution of latent health status approved the phenomenon of adverse selection in all insurance groups, with the exception of rural insurance. Moreover, calculation of the elasticity of medical expenses to reimbursement rate confirmed the existence of moral hazard phenomenon. CONCLUSIONS: Due to the existence of the phenomena of adverse selection and moral hazard in most of health insurances categories, policymakers need to adjust contracts so that to reduce these phenomena. Given the importance of financing, the presence of such problems can lead to less coverage of health insurance provided by insurers, loss of contracts with health care institutions and service providers, and lower quality of health services

Core competencies for health headquarters: a systematic review and meta-synthesis

BACKGROUND: The availability of human resources for the health sector is not enough requirement for addressing health needs. Instead, it is necessary to take effective steps to meet the requirements of the health care system in case the system has the necessary competencies. This study was performed to identify the competencies of health headquarters in meeting the needs of the health system. METHODS: This thematic synthesis was performed to develop a set of central themes that summarize all the topics raised in the articles reviewed in this study. The quality of the articles was assessed by the Standards for Reporting Qualitative Research. RESULTS: We included 12 articles from seven countries. Seven central themes were inductively developed from the analysis: (1) Leadership and management, (2) Analyzing, interpreting, and reporting, (3) Public health knowledge, (4) Interpersonal relationship, (5) Personality competencies, (6) Cultural and community competencies, and (7) International/Global health competencies. CONCLUSION: The findings of this review may help to address how to recruit and retain health headquarters, optimize the headquarters ability and expertise, and develop some approaches to promote their scientific, practical, and professional levels. These issues can drive the organization toward their visions, strategies, and great objectives

A Systematic Literature Review: Workplace Violence Against Emergency Medical Services Personnel

Context: In spite of the high prevalence and consequences of much workplace violence against emergency medical services personnel, this phenomenon has been given insufficient attention. A systematic review can aid the development of guidelines to reduce violence. Objectives: The research question addressed by this paper is, “What are the characteristics and findings of studies on workplace violence against emergency medical services personnel”? Data Sources: A systematic literature review was conducted using online databases (PubMed, Scopus, Google Scholar, and Magiran) with the help of experienced librarians. Study Selection: Inclusion criteria comprised studies in the English or Persian language and researcher’s access to the full text. There was no limit to the entry of the study design. Exclusion criteria included lack of access to the full text of the article, studies published in unreliable journals or conferences, and studies in which the results were shared with other medical or relief groups and there was no possibility of breaking down the results. Data Extraction: A “Data extraction form” was designed by the researchers based on the goals of the study that included the title and author(s), study method (type, place of study, sample size, sampling method, and data collection/analysis tool), printing location, information related to the frequency of types of violence, characteristics of victims /perpetrators, and related factors. Results: The papers reviewed utilized a variety of locations and environments, methods, and instrument samplings. The majority of the studies were performed using the quantitative method. No intervention study was found. Most studies focused on the prevalence of violence, and their results indicated that exposure to violence was high. The results are presented in six major themes. Conclusions: Workplace violence and injuries incurred from it are extensive throughout the world. The important causes of violence include the shortage of training programs dealing with violence, lack of violence management protocols, and delays in response times. Therefore, afterthought and resolve are more crucial than ever. Workplace violence reduction strategies and suggestions for future studies are also discussed

Public hospital facilities development using build-operate-transfer approach: Policy consideration for developing countries

Background: Advantages and limitations of build-operate-transfer (BOT) contracts in various forms of public-private partnership (PPP) arrangements have not been studied. Objectives: This study is the first of its kind to determine the framework, advantages, and limitations of BOT contracts for health care projects in selected countries. Methods: A comparative design was employed to identify factors affecting the development of medical facilities through the adoption of PPPs and the implementation of BOT contracts. England, Spain, Australia, Turkey, and Canada were selected, and data were gathered through well-known databases for the relevant studies. Electronic databases were searched using the keyword terms, �build-operate-transfer,� �public-private partnerships,� �health sector/health system,� �health care facilities,� �Spain,� �Canada,� �England or United Kingdom,� �Turkey,� and �Australia.� Results: The findings revealed that while there was insufficient information transparency for adoption of the BOT contract model in developing medical facilities and building new hospitals, some similarities were observed in its adoption in public fields. Adoption of the BOT contract model has been proven feasible in the selected countries for the health sector, in particular, for the development of new hospitals. These contracts are usually long-term in nature to provide the private sector with the chance to appropriately exploit the field. Different countries utilize this model to meet public regional and long-term health care needs, where the goal is not just a matter of seeking the private sector�s contribution. Conclusions: This study suggests that more information transparency is required for these types of contracts. Factors such as the term of the contract, the maintenance of the facilities built and their post-completion ownership status, facilities and credits offered to the private sector during the construction and operation phases, and the provision of financial and non-financial incentives to the private sector require deeper examination and should also be adjusted to the local contexts of the developing country. © 2016, Iranian Red Crescent Medical Journal

Cancer patients during and after natural and man-made disasters: A systematic review

Background: Disasters affect all social functions. In particular, hospitals must mobilize their resources for response to mass injuries. This process can affected treatment of cancer patients and may resulted in delayed care. Considering the importance of continuity of care for cancer patients, the aim of this systematic review was to identify challenges and preparedness measures for cancer patients during and after disasters. Materials and Methods: This systematic review that was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines between January 2000 to December 2017. The keywords searched included: "disaster," "emergency," "crisis," "disruptive event," "technological disaster," "natural disaster," "cancer," "cancer patient," "chronic disease," "continuity of care," and "patient with chronic disease. "The Google Scholar, ISI Web of Science, Science Direct, PubMed and Scopus databases were searched. Results: After screening and review of article eligibility, seven were included in the study. The selected articles were compared from several aspects. The results showed that most publications concerned all of the chronic diseases or all types of cancers. In addition breast cancer appeared a field of interest in disaster studies. Cancer studies in disaster management usually concentrated less on technological disasters. Conclusion: In aftermath of disasters, the concentration on measures to provide services for injuries and food, water and shelter, results in many challenges for cancer patients. Thus the health system must prepare cancer patients and caregivers for better responses to disasters. In addition, surge capacity must be considered in hospitals and other medical facilities to guarantee continuity of care

Network governance theory as basic pattern for promoting financial support system of the poor in Iranian health system

Background: The share of out-of-pocket payments in Iranian families has the greatest burden on the poor and lead to an impoverishment caused by catastrophic health expenditures. In order to improve access of the poor to public resources, it is necessary to create a better governance system and effective policy-making. The purpose of this study is to improve network effectiveness of the Iranian health system and to design a financial protection network for the poor, based on the network governance theory. Methods: We are using a quantitative method framework in conjunction with a Social network analysis (SNA) strategy. To draw an optimal network, we conducted interviews with experts by focusing on the arrangement and relationship among different institutions. The research sample was purposefully selected. We used UCINET software for data analysis and NetDraw software to draw networks. Results: In this article, an optimal network was proposed with the following characteristics: First, the problem of the density of relationships among several central institutions and the isolation of the other institutions have been solved. Second, in our model, the relationships have been distributed in a balanced manner among all institutions in the network. Third, the number of participants has been reduced and consensus on poor people support policies has been achieved in this optimal network. Forth, executive organizations keep their central positions and upper institutions are not at the central position, so that the power is distributed in favor of more balanced governance. However, in order to increase efficiency and to have coherent decision-making, it is necessary to establish a �core� for this optimal network. The �core� has to include the organizations with the most relationship with others. Conclusion: The result revealed that the usefulness of network analysis as a tool for proposing the effectiveness of governance. By strengthening the relationship among the main actors, an organized system of network management can be achieved. The network has to include all actors from different levels, from policy-making to implementation. The network also has to clarify the tasks from identifying the poor to covering costs. From an academic perspective, this study showed the adequacy of network analysis as a tool for policy sciences. Governance in our optimal health financial protection model follows the shared-governance pattern due to its high density, low centralization and low distance. The model of network governance can be the source of changes in the health governance system. It is a necessary structural condition to provide access to universal health coverage. © 2021, The Author(s)

Selective loss of noradrenaline exacerbates early cognitive dysfunction and synaptic deficits in APP/PS1 mice.

Background: Degeneration of the locus coeruleus (LC), the major noradrenergic nucleus in the brain, occurs early and is ubiquitous in Alzheimer’s disease (AD). Experimental lesions to the LC exacerbate AD-like neuropathology and cognitive deficits in several transgenic mouse models of AD. Because the LC contains multiple neuromodulators known to affect amyloid toxicity and cognitive function, the specific role of noradrenaline (NA) in AD is not well understood. Methods: To determine the consequences of selective NA deficiency in an AD mouse model, we crossed dopamine -hydroxylase (DBH) knockout mice with amyloid precursor protein (APP)/presenilin-1 (PS1) mice overexpressing mutant APP and PS1. Dopamine -hydroxylase (/) mice are unable to synthesize NA but otherwise have normal LC neurons and co-transmitters. Spatial memory, hippocampal long-term potentiation, and synaptic protein levels were assessed. Results: The modest impairments in spatial memory and hippocampal long-term potentiation displayed by young APP/PS1 or DBH (/) single mutant mice were augmented in DBH (/)/APP/PS1 double mutant mice. Deficits were associated with reduced levels of total calcium/calmodulin-dependent protein kinase II and N-methyl-D-aspartate receptor 2A and increased N-methyl-D-aspartate receptor 2B levels and were independent of amyloid accumulation. Spatial memory performance was partly improved by treatment with the NA precursor drug L-threo-dihydroxyphenylserine. Conclusions: These results indicate that early LC degeneration and subsequentNAdeficiency inADmay contribute to cognitive deficits via altered levels of calcium/calmodulin-dependent protein kinase II and N-methyl-D-aspartate receptors and suggest that NA supplementation could be beneficial in early AD

Anticonvulsant and neuroprotective effects of Pimpinella anisum in rat brain

Background: Essential oil of Pimpinella anisum L. Apiaceae (anise oil) has been widely used in traditional Persian medicine to treat a variety of diseases, including some neurological disorders. This study was aimed to test the possible anti-seizure and anti-hypoxia effects of anise oil. Methods: The effects of different concentrations of anise oil were tested on seizure attacks induced by pentylenetetrazol (PTZ) injection and neuronal hypoxia induced by oxygen withdrawal as well as on production of dark neurons and induction of long-term potentiation (LTP) in in vivo and in vitro experimental models of rat brain. Results: Anise oil significantly prolonged the latency of seizure attacks and reduced the amplitude and duration of epileptiform burst discharges induced by injection of intraperitoneal PTZ. In addition, anise oil significantly inhibited production of dark neurons in different regions of the brain in epileptic rats. Anise oil also significantly enhanced the duration of the appearance of anoxic terminal negativity induced by oxygen withdrawal and inhibited induction of LTP in hippocampal slices. Conclusions: Our data indicate the anticonvulsant and neuroprotective effects of anise oil, likely via inhibition of synaptic plasticity. Further evaluation of anise oil to use in the treatment of neurological disorders is suggested