Formation flight investigation for highly efficient future civil transport aircraft

Formation flight could greatly assist the air transport industry in tackling the challenges of environmental impact, excessive reliance on fuel and overcapacity. Previous studies have shown drag reductions leading to significant fuel savings for aircraft in formation relative to their solo flight. Safety is guaranteed with the use of extended formation distances, and practical implementation issues could be solved in the near future. Since studies so far have focused on existing aircraft configurations and technology, a case study using a strut-braced wing airliner was carried out to ascertain its applicability to less conventional craft. The present results did not indicate such clear-cut benefits. If formation flight is to be successful and beneficial for the next generations of aircraft, it will be vital to consider its interaction with new technologies developed for highly efficient operation, in particular those aimed at reduction of aircraft drag such as laminar flow, and to do so early in the design of aerospace vehicles and wider systems

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

Main Determinants of Supplementary Health Insurance Demand: (Case of Iran)

INTRODUCTION: In the majority of developing countries, the volume of medical insurance services, provided by social insurance organizations is inadequate. Thus, supplementary medical insurance is proposed as a means to address inadequacy of medical insurance. Accordingly, in this article, we attempted to provide the context for expansion of this important branch of insurance through identification of essential factors affecting demand for supplementary medical insurance. METHOD: In this study, two methods were used to identify essential factors affecting choice of supplementary medical insurance including Classification and Regression Trees (CART) and Bayesian logit. To this end, Excel® software was used to refine data and R® software for estimation. The present study was conducted during 2012, covering all provinces in Iran. Sample size included 18,541 urban households, selected by Statistical Center of Iran using 3-stage cluster sampling approach. In this study, all data required were collected from the Statistical Center of Iran. RESULTS: In 2012, an overall 8.04 of the Iranian population benefited from supplementary medical insurance. Demand for supplementary insurance is a concave function of age of the household head, and peaks in middle-age when savings and income are highest. The present study results showed greater likelihood of demand for supplementary medical insurance in households with better economic status, higher educated heads, female heads, and smaller households with greater expected medical expenses, and household income is the most important factor affecting demand for supplementary medical insurance. CONCLUSION: Since demand for supplementary medical insurance is hugely influenced by households' economic status, policy-makers in the health sector should devise measures to improve households' economic or financial access to supplementary insurance services, by identifying households in the lower economic deciles, and increasing their financial ability to pay. Moreover, insurance companies should adjust their insurance policy according to clients' needs, household characteristics, and their incomes

Macroscopic and microscopic description of phase transition in cerium isotopes

The spherical-to-deformed phase transition in cerium isotopes recently suggested to occur between Ce146 and Ce148 has been examined in the framework of the macroscopic algebraic collective model and two microscopic approaches, namely Skyrme-Hartree-Fock + Bardeen-Cooper-Schrieffer (BCS) calculations and the symmetry conserving configuration mixing method with Gogny energy density functionals applied also to the neighboring nuclei along the cerium isotopic chain. Possible spectral signatures of the phase transition are discussed in more details. The microscopic calculations predict octupole softness manifested by rather flat potential energy curves as a function of the octupole deformation parameter β3 for Ce146 and Ce148 and shape coexistence characterized by axially symmetric 0+ states, triaxial 2+ bands, and octupole deformation for the lowest 1- state

Herpes simplex virus type-1(HSV-1) oncolytic and highly fusogenic mutants carrying the NV1020 genomic deletion effectively inhibit primary and metastatic tumors in mice

Background. The NV1020 oncolytic herpes simplex virus type-1 has shown significant promise for the treatment of many different types of tumors in experimental animal models and human trials. Previously, we described the construction and use of the NV1020-like virus OncSyn to treat human breast tumors implanted in nude mice. The syncytial mutation gKsyn1 (Ala-to-Val at position 40) was introduced into the OncSyn viral genome cloned into a bacterial artificial chromosome using double-red mutagenesis in E. coli to produce the OncdSyn virus carrying syncytial mutations in both gB(syn3) and gK(syn1). Results. The OncdSyn virus caused extensive virus-induced cell fusion in cell culture. The oncolytic potential of the OncSyn and OncdSyn viruses was tested in the highly metastatic syngeneic mouse model system, which utilizes 4T1 murine mammary cancer cells implanted within the interscapular region of Balb/c mice. Mice were given three consecutive intratumor injections of OncSyn, OncdSyn, or phosphate buffered saline four days apart. Both OncSyn and OncdSyn virus injections resulted in significant reduction of tumor sizes (p \u3c 0.05) compared to control tumors. Virus treated mice but not controls showed a marked reduction of metastatic foci in lungs and internal organs. Mouse weights were not significantly impacted by any treatment during the course of the entire study (p = 0.296). Conclusion. These results show that the attenuated, but highly fusogenic OncSyn and OncdSyn viruses can effectively reduce primary and metastatic breast tumors in immuncompetent mice. The available bac-cloned OncSyn and OncdSyn viral genomes can be rapidly modified to express a number of different anti-tumor and immunomodulatory genes that can further enhance their anti-tumor potency. © 2008 Israyelyan et al; licensee BioMed Central Ltd

Qualitative Analysis of Causal Anisotropic Viscous Fluid Cosmological Models

The truncated Israel-Stewart theory of irreversible thermodynamics is used to describe the bulk viscous pressure and the anisotropic stress in a class of spatially homogeneous viscous fluid cosmological models. The governing system of differential equations is written in terms of dimensionless variables and a set of dimensionless equations of state is utilized to complete the system. The resulting dynamical system is then analyzed using standard geometric techniques. It is found that the presence of anisotropic stress plays a dominant role in the evolution of the anisotropic models. In particular, in the case of the Bianchi type I models it is found that anisotropic stress leads to models that violate the weak energy condition and to the creation of a periodic orbit in some instances. The stability of the isotropic singular points is analyzed in the case with zero heat conduction; it is found that there are ranges of parameter values such that there exists an attracting isotropic Friedmann-Robertson-Walker model. In the case of zero anisotropic stress but with non-zero heat conduction the stability of the singular points is found to be the same as in the corresponding case with zero heat conduction; hence the presence of heat conduction does not apparently affect the global dynamics of the model.Comment: 35 pages, REVTeX, 3 Encapsulated PostScript Figure

Qualitative Analysis of Viscous Fluid Cosmological Models satisfying the Israel-Stewart theory of Irreversible Thermodynamics

Isotropic and spatially homogeneous viscous fluid cosmological models are investigated using the truncated Israel-Stewart theory of irreversible thermodynamics to model the bulk viscous pressure. The governing system of differential equations is written in terms of dimensionless variables and a set of dimensionless equations of state is then utilized to complete the system. The resulting dynamical system is analyzed using geometric techniques from dynamical systems theory to find the qualitative behaviour of the Friedmann-Robertson-Walker models with bulk viscosity. In these models there exists a free parameter such that the qualitative behaviour of the models can be quite different (for certain ranges of values of this parameter) from that found in models satisfying the Eckart theory studied previously. In addition, the conditions under which the models inflate are investigated.Comment: 29 pages, 8 Encapsulated PostScript Figures, uses the IOP style file

Exact Solutions of Five Dimensional Anisotropic Cosmologies

We solve the five dimensional vacuum Einstein equations for several kinds of anisotropic geometries. We consider metrics in which the spatial slices are characterized as Bianchi types-II and V, and the scale factors are dependent both on time and a non-compact fifth coordinate. We examine the behavior of the solutions we find, noting for which parameters they exhibit contraction over time of the fifth scale factor, leading naturally to dimensional reduction. We explore these within the context of the induced matter model: a Kaluza-Klein approach that associates the extra geometric terms due to the fifth coordinate with contributions to the four dimensional stress-energy tensor.Comment: 11 page

Glycoprotein B of human herpesvirus 8 is a component of the virion in a cleaved form composed of amino- and carboxyl-terminal fragments

Human herpesvirus 8 (HHV-8) or Kaposi\u27s sarcoma-associated herpesvirus (KSHV) is the only known human member of the Rhadinovirus genus of the gammaherpesvirus subfamily. Antibodies against peptides representing portions of the amino-and carboxyl-termini of HHV-8 gB were produced and used to detect gB expression in Vero cells transfected with the gB gene, in the HHV- 8-harboring cell line, BCBL-1, and in purified virions. Expression of gB was detected in approximately 3% of uninduced BCBL-1 cells, while up to 30% of the cells expressed gB after 12-O-tetradecanoylphorbol-13-acetate (TPA) induction of virus replication. Indirect immunofluorescence assays and confocal microscopy showed that gB was distributed throughout the cytoplasm of BCBL-1 cells and transfected Vero cells. Immunoblot analyses of virion preparations revealed the presence of full-length as well as two smaller than full-length gB-derived species corresponding to the amino- and carboxy- terminal portions of gB, respectively. Biochemical analysis of the gB carbohydrate moieties using glycosylation inhibitors revealed that gB contained N-linked oligosacharides of the high-mannose type, characteristic of precursor carbohydrate chains added in the endoplasmic reticulum. (C) 2000 Academic Press

Classification of Higher Dimensional Spacetimes

We algebraically classify some higher dimensional spacetimes, including a number of vacuum solutions of the Einstein field equations which can represent higher dimensional black holes. We discuss some consequences of this work.Comment: 16 pages, 1 Tabl