ULTRA-SHARP nonoscillatory convection schemes for high-speed steady multidimensional flow

For convection-dominated flows, classical second-order methods are notoriously oscillatory and often unstable. For this reason, many computational fluid dynamicists have adopted various forms of (inherently stable) first-order upwinding over the past few decades. Although it is now well known that first-order convection schemes suffer from serious inaccuracies attributable to artificial viscosity or numerical diffusion under high convection conditions, these methods continue to enjoy widespread popularity for numerical heat transfer calculations, apparently due to a perceived lack of viable high accuracy alternatives. But alternatives are available. For example, nonoscillatory methods used in gasdynamics, including currently popular TVD schemes, can be easily adapted to multidimensional incompressible flow and convective transport. This, in itself, would be a major advance for numerical convective heat transfer, for example. But, as is shown, second-order TVD schemes form only a small, overly restrictive, subclass of a much more universal, and extremely simple, nonoscillatory flux-limiting strategy which can be applied to convection schemes of arbitrarily high order accuracy, while requiring only a simple tridiagonal ADI line-solver, as used in the majority of general purpose iterative codes for incompressible flow and numerical heat transfer. The new universal limiter and associated solution procedures form the so-called ULTRA-SHARP alternative for high resolution nonoscillatory multidimensional steady state high speed convective modelling

Streptozotocin induced oxidative stress, innate immune system responses and behavioral abnormalities in male mice

Recent evidence indicates the involvement of inflammatory factors and mitochondrial dysfunction in the etiology of psychiatric disorders such as anxiety and depression. To investigate the possible role of mitochondrial-induced sterile inflammation in the co-occurrence of anxiety and depression, in this study, we treated adult male mice with the intracerebroventricular (i.c.v.) infusion of a single low dose of streptozotocin (STZ, 0.2 mg/mouse). Using valid and qualified behavioral tests for the assessment of depressive and anxiety-like behaviors, we showed that STZ-treated mice exhibited behaviors relevant to anxiety and depression 24 h following STZ treatment. We observed that the co-occurrence of anxiety and depressive-like behaviors in animals were associated with abnormal mitochondrial function, nitric oxide overproduction and, the increased activity of cytosolic phospholipase A2 (cPLA2) in the hippocampus. Further, STZ-treated mice had a significant upregulation of genes associated with the innate immune system such as toll-like receptors 2 and 4. Pathological evaluations showed no sign of neurodegeneration in the hippocampus of STZ-treated mice. Results of this study revealed that behavioral abnormalities provoked by STZ, as a cytotoxic agent that targets mitochondria and energy metabolism, are associated with abnormal mitochondrial activity and, consequently the initiation of innate-inflammatory responses in the hippocampus. Our findings highlight the role of mitochondria and innate immunity in the formation of sterile inflammation and behaviors relevant to anxiety and depression. Also, we have shown that STZ injection (i.c.v.) might be an animal model for depression and anxiety disorders based on sterile inflammation

General Practitioners and Breast Imaging Modalities: Their Knowledge and Associated Determinants

Background: General practitioners (GPs) are usually the first-line doctors visiting patients with breast problems. Therefore, their knowledge about breast diseases is of significant importance for proper screening and referral of patients and warrants scrutiny. The purpose of this study was to assess the knowledge of GPs regarding different breast imaging modalities. Methods: In this cross-sectional study, we asked participants in an annual GP conference to complete a structured questionnaire. The questionnaire elicited information about the GP’s characteristics such as age, gender and work experience and eight multiple choice questions about how to use different imaging modalities and manage patients with breast disorders were also proposed. Results: In total, 270 GPs completed the questionnaire (155 females and 115 males). The results showed a significant association between frequency of GPs choosing the correct imaging modality in a 50-year-old asymptomatic patient and participants' age (?40) and duration of work experience (?5) (P = 0.002 and P = 0.016, respectively). Also, a significant association was revealed between gender of GPs (female) and correct answers regarding management of nipple discharge (P = 0.024). There were no significant associations between the other variables and answers to the other questions. Conclusions: The findings of this study highlight the importance of implementing continuous medical education for GPs in approach to breast diseases

Effects of chronic hypoxia on the expression of seladin-1/Tuj1 and the number of dark neurons of hippocampus

Background: There are evidences showing the relation between chronic hypoxia and Alzheimer&#39;s disease (AD) as a metabolic neurodegenerative disease. This study was designed to evaluate the effects of chronic hypoxia on factors which characterized in AD to introduce a new model of AD-dementia. Methods and materials: Twenty-four male rats were randomly divided in three groups: Control group (Co), Sham group (Sh), Hypoxia induction group (Hx, exposed to hypoxic chamber [oxygen 8% and nitrogen 92%] for 30 days, 4 h/day). Spatial learning and memory were analyzed using the Morris water maze task. At day 30 after hypoxia period, animals were sacrificed and serum was gathered for pro-inflammatory cytokines (interleukin-1 beta and tumor necrosis factor) measurements and brains were used for molecular and histopathological investigations. Results: According to behavioral studies, a significant impairment was seen in Hx group (P &lt; 0.05). TNF-alpha and IL-1 beta showed a significant enhanced in Hx group comparing with Co group and Sh group (P &lt; 0.05). As well, the gene expression of seladin-1, Tuj1 and the number of seladin-1 +, Tuj1 +neurons significantly decreased and also the mean number of dark neurons significantly increased in CA1 and CA3 regions of hippocampus. Conclusions: In this study, a new model of AD was developed which showed the underlying mechanisms of AD and its relations with chronic hypoxia. Hypoxia for 30 days decreased seladin-1, Tuj1 expression, increased the number of dark neurons, and also induced memory impairment. These results indicated that chronic hypoxia mediated the dementia underlying AD and AD-related pathogenesis in rat.</p

Implementation of a National Measles Elimination Program in Iran: Phylogenetic Analysis of Measles Virus Strains Isolated during 2010–2012 Outbreaks

<div><p>Measles virus (MV) causes small and large outbreaks in Iran. Molecular assays allow identifying and the sources of measles imported from neighboring countries. We carried out a phylogenetic analysis of measles virus circulating in Iran over the period 2010–2012. Specimens from suspected cases of measles were collected from different regions of Iran. Virus isolation was performed on urine and throat swabs. Partial nucleoprotein gene segments of MV were amplified by RT-PCR. PCR products of 173 samples were sequenced and analyzed. The median age of confirmed cases was 2 years. Among all confirmed cases, 32% had unknown vaccination status, 20% had been vaccinated, and 48% had not been vaccinated. Genotypes B3 and D8 (for the first time), H1 and D4 were detected mainly in unvaccinated toddlers and young children. Genotype B3 became predominant in 2012 and was closely related to African strains. H1 strains were also found in small and large outbreaks during 2012 but were not identical to Iranian H1-2009 strains. A majority of the Iranian D4 strains during 2010–2012 outbreaks were linked to the D4 strain identified in the Pakistan in 2007. We identified a single case in 2010 belonging to D8 genotype with 99.7% identity to Indian isolates. Although the vaccination program is currently good enough to prevent nationwide epidemics and successfully decreased measles incidence in Iran, the fraction of protected individuals in the population was not high enough to prevent continuous introduction of cases from abroad. Due to increasing number of susceptible individuals in some areas, sustained transmission of the newly introduced viral genotype remains possible.</p></div

Age distribution of measles cases related to geographical location, Iran, 2010–2012 (n = 173).

<p>Age distribution of measles cases related to geographical location, Iran, 2010–2012 (n = 173).</p

Geographical distribution of measles virus genotypes in Iran (1^st May 2010–30^th December 2012).

<p>Numbers and type of genotypes are shown in boxes.</p

Phylogenetic tree of the C-terminus of N gene sequences of 63selected wild-type measles isolates from Iran compared to the reference sequences for each genotype.

<p>The Iranian sequences are belonged to B3, D8, D4 and H1 genotypes during 2010–2012. Bootstrap values (1,000 replicates) >70% are indicated. Closely related reference sequences to the Iranian strains are shown by dark rhombic. Scale bar indicates base substitutions per site. Accession numbers of WHO reference sequences are: Genotype A (U01987), B1 (U01998), B2 (U01994), B3.1 (AJ232203), B3.2 (L46753), C1 (AJ232203), D3 (U01977),D4 (U01976), D6 (L46750), D8 (AF280803), D9 (AF481485), D10 (AY923185), E (X84879), F(X84865), G1(U01974), G2(AF171232), G3(AY184217), H1(AF045212), H2(AF045217).</p