Lovelock Thin-Shell Wormholes

We construct the asymptotically flat charged thin-shell wormholes of Lovelock gravity in seven dimensions by cut-and-paste technique, and apply the generalized junction conditions in order to calculate the energy-momentum tensor of these wormholes on the shell. We find that for negative second order and positive third order Lovelock coefficients, there are thin-shell wormholes that respect the weak energy condition. In this case, the amount of normal matter decreases as the third order Lovelock coefficient increases. For positive second and third order Lovelock coefficients, the weak energy condition is violated and the amount of exotic matter decreases as the charge increases. Finally, we perform a linear stability analysis against a symmetry preserving perturbation, and find that the wormholes are stable provided the derivative of surface pressure density with respect to surface energy density is negative and the throat radius is chosen suitable.Comment: 13 pages, 6 figure

Realist evaluation of UK medical education quality assurance

OBJECTIVES: The aim of the study was to explore what components of the General Medical Council’s (GMC) Quality Assurance Framework work, for whom, in what circumstances and how? SETTING: UK undergraduate and postgraduate medical education and training. PARTICIPANTS: We conducted interviews with a stratified sample of 36 individuals. This included those who had direct experiences, as well as those with external insights, representing local, national and international organisations within and outside medicine. INTERVENTION: The GMC quality assure education to protect patient and public safety utilising complex intervention components including meeting standards, institutional visits and monitoring performance. However, the context in which these are implemented matters. We undertook an innovative realist evaluation to test an initial programme theory. Data were analysed using framework analysis. RESULTS: Across components of the intervention, we identified key mechanisms, including transparent reporting to promote quality improvement; dialogical feedback; partnership working facilitating interactions between regulators and providers, and role clarity in conducting proportionate interventions appropriate to risk. The GMC’s framework was commended for being comprehensive and enabling a broad understanding of an organisation’s performance. Unintended consequences included confusion over roles and boundaries in different contexts which often undermined effectiveness. CONCLUSIONS: his realist evaluation substantiates the literature and reveals deeper understandings about quality assuring medical education. While standardised approaches are implemented, interventions need to be contextually proportionate. Routine communication is beneficial to verify data, share concerns and check risk; however, ongoing partnership working can foster assurance. The study provides a modified programme theory to explicate how education providers and regulators can work more effectively together to uphold education quality, and ultimately protect public safety. The findings have influenced the GMC’s approach to quality assurance which impacts on all medical students and doctors in training

Pluralism in qualitative research: the impact of different researchers and qualitative approaches on the analysis of qualitative data.

Qualitative approaches to research in psychology and the social sciences are increasingly used. The variety of approaches incorporates different epistemologies, theoretical traditions and practices with associated analysis techniques spanning a range of theoretical and empirical frameworks. Despite the increase in mixed method approaches it is unusual for qualitative methods to be used in combination with each other. The Pluralism in Qualitative Research project (PQR) was developed in order to investigate the benefits and creative tensions of integrating diverse qualitative approaches. Amongst other objectives it seeks to interrogate the contributions and impact of researchers and methods on data analysis. The paper presents our pluralistic analysis of a single semi-structured interview transcript. Analyses were carried out by different researchers using grounded theory, Foucauldian discourse analysis, interpretative phenomenological analysis and narrative analysis. We discuss the variation and agreement in the analysis of the data. The implications of the findings on the conduct, writing and presentation of qualitative research are discussed

Neuropathological changes in the PDAPP transgenic mouse model of Alzheimer's disease

Alzheimer's disease (AD) is a uniquely human disorder. Although the pathogenesis of AD is not fully understood, growing evidence indicates that the deposition of beta-amyloid (Aβ) and the local reactions of various cell types to this protein play major roles in the development of the disease. In the present study transgenic mice expressing mutant amyloid precursor protein (APP) has been used. These mice exhibit selective neuronal death in the brain regions that are most affected in AD, suggesting that amyloid plaque formation is directly involved in AD neurons loss. Brains from 12 transgenic animals and 12 age-matched non transgenic littermate controls (1 and 2 years old) were examined histopathologically. One year old transgenic animals (n=6) exhibit deposits of human Aβ in the hippocampus, corpus callosum and cerebral cortex. By 2 years of age, a great number of diffuse and mature plaques were present in the cortex and hippocampus, and subcortical regions like thalamus and striatum. Another major finding was reduction of cholinergic cells in the medial septum, striatum and diagonal band of Broca. The present data are consistent with the hypothesis that the neuropathology begins in the cerebral cortex and hippocampus before spreading in a retrograde fashion to subcortical regions

Morphology and synaptic organization of non-dopaminergic nigral projections to the medio dorsal thalamic nucleus of the rat, a study by anterograde transport of PHA-L

Background: Mediodorsal (MD) thalamic nucleus, which is considered to take place between extra pyramidal and limbic feedback circuit, receives projective fibers from ventrolateral neurons of reticular part of substantia nigra (SNr). In order to better understand the influence and chemical reaction of these fibers upon MD nucleus, the morphology and synaptology of them were examined in the present study. Methods: Phaseolous vulgaris-leucoagglutin (PHA-L) was injected into substantia nigra pars reticulate. After 3-4 days, the sections of SNr injection site and MD nucleus were prepared. Then, we examined organization, morphology and, synaptology of PHA-L labeled SNr fibers that go to caudal and lateral part of MD thalamic nucleus. Results: At the electron microscopic level, the SNr terminals made synapses predominantly with the medium to small dendrites and far less frequently with soma and large dendrites. These terminals were packed with polymorphic synaptic vesicles and formed symmetrical synapses; furthermore, it has been already recognized that cortico straital fibers from sensory-motor cortex go to region of the SNr that give rise to the nigrothalamic fibers. Conclusion: This data suggest that upon the synaptic organization, morphology and chemical nature of GABAergic, SNr fibers may have different inhibitory influence on MD neurons regulating the thalamic output from MD to cerebral cortex in the control of limbic and extra pyramidal feedback system

Comparison of antimicrobial and wound-healing effects of silver nanoparticle and chlorhexidine mouthwashes: an in vivo study in rabbits

The objective is to formulate a silver nanoparticle mouthwash and then evaluate its antimicrobial and wound-healing effects in rabbit animal models. Microbial samples were collected from the oral cavity of 60 rabbits. Thereafter, standardized wounds were created in the lateral border of the tongue on the right side for all rabbits. After surgery, digital photographs were obtained from the wounds with standardized settings. To characterize the silver nanoparticles used in the synthetic mouthwash, transmission electron microscopy (TEM) and digital light scattering analysis were used. The animal models were then randomly divided into 4 groups: group 1 received 9.80 wt% silver nanoparticle mouthwash; group 2 received all the ingredients of the formulated mouthwash except for silver nanoparticles; group 3 received chlorhexidine 2.0% mouthwash; and the negative control group did not receive any postoperative mouthwash. Microbial samples were collected from oral cavity of the rabbits each day for four postoperative days. Colony-forming unit (CFU) counts were compared post-operatively with the pre-operative counts. In addition, standardized digital photographs were taken each day from the wounds and the area of the wounds was compared in postoperative and pre-operative images. Data were statistically analyzed using one-way ANOVA and repeated measures variance analysis (α = 0.05). TEM revealed spherical morphology of silver nanoparticles and digital light scattering showed an average size of 5 nm and optimal distribution of the nanoparticles. CFU count significantly decreased in groups 1 and 3 (P 0.05). Silver nanoparticle mouthwash possesses favorable antibacterial and wound-healing effects. The formulated 9.80 wt% silver nanoparticle mouthwash with a particle size of 5 nm can be a promising alternative for application after oral surgical procedures

Designing two models for comprehensive center of excellence and center of excellence in the field of medical sciences in Iran

Background: Despite exist several centers of excellence in the various medical field in the country, most of them lack a single procedure and organizational structures in their functioning, organizing, targeting, etc. So the study aimed to design an organizational model that meets the goals and mission of them in the field of medical sciences. Methods: This qualitative and applied research was conducted in two comparative and analytical stages from May 2016 to February 2017 in Iran. The location of the study includes a university, research institute, health center, or research center known as a center of excellence. In the analytical stage, 10 experts and managers of the top centers were selected through a targeted sampling method as a study sample. In the comparative section, all 50 centers of excellence and similar specimens in the world were selected. The data collection tool was a semi-structured interview in the analytical section and the ministry of health's documents. In comparative section data, bases and official sites of the centers were analyzed. Results: The term "center of excellence" for units that play a role in one or two of the three dimensions of education, research, and treatment, and the term "comprehensive center of excellence" for a unit that plays a role in all three dimensions, in addition to knowledge management have been agreed upon. Seven missions (national and international) for the comprehensive center of excellence and five different missions for center of excellence were formulated. The role of the ministry of health in the guidance of these centers was agreed in the seven items. Ultimately, the macro model of organizing "comprehensive centers of excellence" and "centers of excellence" at the university level and ministry of health level was designed and presented. Conclusion: Correcting the governance structure of these centers in ministry, unit command at the highest level of management by reorganizing of duties, the authority of High Council for the Center of Excellences and the establishment of a systematic relationship between ministry and vices are the part of the requirements for fulfilling the roles and mission of center of excellence. © 2020 Tehran University of Medical Sciences. All rights reserved

Энергетические ресурсы Ирана и их воздействие на окружающую среду

The paper presents an analysis of main sources of energy resource production and their sale  in the domestic and export markets. The authors have analyzed type of domestic energy consumers and estimated their environmental impacts. The paper shows that the shift to alternative energy sources will reduce an ecological impact on the environment.Проанализированы основные источники добычи энергоресурсов и их реализация как на внутреннем рынке, так и на внешнем. Проведен анализ типа потребителей энергоресурсов внутри страны и дана оценка их воздействия на окружающую среду. Показано, что переход на альтернативные источники позволит уменьшить экологическое воздействие на окружающую среду

Two-photon Lithography for 3D Magnetic Nanostructure Fabrication

Ferromagnetic materials have been utilised as recording media within data storage devices for many decades. Confinement of the material to a two dimensional plane is a significant bottleneck in achieving ultra-high recording densities and this has led to the proposition of three dimensional (3D) racetrack memories that utilise domain wall propagation along nanowires. However, the fabrication of 3D magnetic nanostructures of complex geometry is highly challenging and not easily achievable with standard lithography techniques. Here, by using a combination of two-photon lithography and electrochemical deposition, we show a new approach to construct 3D magnetic nanostructures of complex geometry. The magnetic properties are found to be intimately related to the 3D geometry of the structure and magnetic imaging experiments provide evidence of domain wall pinning at a 3D nanostructured junction