Note on the single-shock solutions of the Korteweg-de Vries-Burgers equation

The well-known shock solutions of the Korteweg-de Vries-Burgers equation are revisited, together with their limitations in the context of plasma (astro)physical applications. Although available in the literature for a long time, it seems to have been forgotten in recent papers that such shocks are monotonic and unique, for a given plasma configuration, and cannot show oscillatory or bell-shaped features. This uniqueness is contrasted to solitary wave solutions of the two parent equations (Korteweg-de Vries and Burgers), which form a family of curves parameterized by the excess velocity over the linear phase speed.Comment: Accepted for publication in Astrophysics & Space Scienc

Spatial analysis of breast cancer incidence in Iran

Breast cancer (BC) is the most common cancer in females (27 of the total) and the main cause of death (16) due to cancer in women in developed and developing countries. Variations in its incidence rate among geographical areas are due to various contributing factors. Since there have been a lack of studies on this topic in our country, the present spatial analysis of breast cancer incidence in Iran in 2009 was conducted using data from the national cancer registry system. The reported incidences of the disease were standardized according to the World Health Organization population and the direct method. Then data was inserted into the GIS software and finally, using the Hot Spot Analysis (Geties-Ord Gi), high-risk areas were drawn. Provinces with incidences 1.96 SD higher or lower than the national average were considered as hot spots or cold spots, at the significance level of 0.05. In 2009, a total of 7,582 cases of BC occurred in Iran. The annual incidence was 33.2 per hundred thousand people. Our study showed that the highest incidence of BC in women occurred in the central provinces of the country, Tehran, Isfahan, Yazd, Markazi and Fars. The results of hot spots analysis showed that the distribution of high-risk BC was focused in central parts of Iran, especially Isfahan province (p < 0.01). The other provinces were not significantly different from the national average. The higher incidence in central provinces may be due to greater exposure to carcinogens in urban areas, a Western lifestyle and high prevalence of other risk factors. Further epidemiological studies about the etiology and early detection of BC are essential. © 2016, Asian Pacific Journal of Cancer Prevention

Spatial analysis of colorectal cancer in Iran

Colorectal cancer is one of the most common cancers. Due to demographic changes, it is predicted that the incidence of this cancer will increase. Variations of its incidence rate among geographical areas are due to various contributing factors. Since there have been a lack of studies on this topic in our country, the present assessment of spatial patterns of colorectal cancer incidence in Iran was performed. In this ecological study, the new cases of colon cancer were extracted from Cancer Registry Center report of the Health Deputy of Iran in 2009. The reported incidences of the disease were standardized on the basis of the World Health Organization population and the direct method. Then the data were inserted into the GIS software, and finally, using the analysis of hot spots (Getis-Ord Gi) high-risk areas were drawn. Provinces that are higher or lower than the national average (1.9 SD) were considered hot spots or cold spots, significant at the level of 0.05. A total of 6,210 cases of colorectal cancer were registered in Iran in 2009, of which 3,727 were in men and 2,783 in women (age-standardized rates of 11.3 and 10.9 per 100,000 population, respectively). The results showed that in central and northern Iran including Isfahan, Qom, Tehran, Qazvin and Mazandaran significant hot spots in men were present (p < 0.05). In women also we have high incidence in northern and central states: Mazandaran province (p < 0.01) and the province of Tehran (p < 0.05) had higher incidences than the national average and were apparent as significant hot spots. Analysis of the spatial distribution of colorectal cancer showed significant differences between different areas pointing to the necessity for further epidemiological studies into the etiology and early detection. © 2016, Asian Pacific Journal of Cancer Prevention

The status of Iran measles surveillance system in 2014

The results showed success of the health system to detect suspected cases of the measles and appropriate sampling from suspected cases that were more than expected. In addition, per every one million population of Iran in 2014, 1.27 of cases of measles were reported; that a numbers of confirmed cases observed in Afghan refugees. Low levels of immunization coverage in eastern neighboring countries and high immigration to Iran, are the main challenge of measles elimination in Iran. The gradual accumulation of susceptible individuals, due to lack of proper vaccination or failure to respond to immunization, may underlie the development of outbreaks of measles in Iran. © 2015, Isfahan University of Medical Sciences(IUMS). All rights reserved

Optical coherence tomography angiography of foveal hypoplasia

AIMS: To discuss foveal development in the context of detailed retinal vasculature imaging in foveal hypoplasia using optical coherence tomography angiography. METHODS: In this case series, the optical coherence tomography angiography results of four patients with idiopathic foveal hypoplasia and two patients with foveal hypoplasia secondary to oculocutaneous albinism are presented. RESULTS: Cases with intact visual acuity demonstrated lower grades of foveal hypoplasia on optical coherence tomography, while those with poor vision demonstrated high grades of foveal hypoplasia. The superficial retinal capillary plexus was intact in the foveal area in all cases, with no demonstrable foveal avascular zone. The deep retinal capillary plexus was absent to variable degrees in most cases, but was most persistent in those cases with reduced vision. CONCLUSIONS: The superficial retinal capillary plexus is present in cases with foveal hypoplasia, while the deep retinal capillary plexus is absent to varying degrees. Our findings support the hypothesis that an intact foveal avascular zone of the deep capillary plexus allows for outer retinal photoreceptor specialisation to occur unimpeded, resulting in preserved visual acuity, while this process may be inhibited by an absent deep capillary foveal avascular zone with resultant poor vision

Whipple procedure: A review of a 7-year clinical experience in a referral center for hepatobiliary and pancreas diseases

Background: Pancreatic cancer is generally found in the older population Pancreaticoduodenectomy seems to be the only way in resolving these resectable tumors. Allen. O Whipple was the first to describe pancreaticoduodenectomy in 1935 as a modified procedure. This article is a case series with respect to the 7-year experience of the Whipple procedure in Firoozgar Teaching Hospital. Methods: Patient surgery details were gathered from the surgical records of the operating room and their clinical records from the hospital archives. Data was analyzed with SPSS software (version 16.0.1). Those patients, whose tumor had invaded the superior mesenteric artery, had extensive portal vein involvement or distant metastasis was considered as unresectable. Results: The first Whipple procedure was recorded in our hospital in 2008. From 2008 till 20 March 2014, 70 cases were collected and analyzed. The mean age of cases was 58.4 years, the mean hospital stay length was 12.9 days (�±6.23 days), mean operation time was 376 min (�±37.3 min),. The most common presenting symptom was jaundice (78.6 ). Delayed gastric emptying was the most common post-operative complication. The most prevalent cause of reoperation was intra-abdominal abscess. Major morbidities of these patients consisted of cardiac arrhythmias (21.4) and pneumonia (10). Minor complications were wound infection (17.1) and delayed gastric emptying (32.9). The statistics revealed pancreatic anastomosis failure as 2.9 and a decrease in mortality rate from 50 during the first years of this study to 16 to 20 during the last years. Conclusions: In this case series, the time of operation decreased during the recent years .Analysis shows a correlation between operation time and pack cell transfused during the operation, but no correlation was found between operation time and post-operation hospitalization course. It is true that hospital setting, socioeconomic level of the patients including their compliance, and the expertise of the surgeons and surgical staff can have an influence on the result of this operation, but it seems that the magnitude of the surgical stress of this procedure and the (compromised) functional reserve of this patient population can be a notable factor influencing the outcome. �© 2015 Saraee et al

An improved joint model: POS tagging and dependency parsing

Dependency parsing is a way of syntactic parsing and a natural language that automatically analyzes the dependency structure of sentences, and the input for each sentence creates a dependency graph. Part-Of-Speech (POS) tagging is a prerequisite for dependency parsing. Generally, dependency parsers do the POS tagging task along with dependency parsing in a pipeline mode. Unfortunately, in pipeline models, a tagging error propagates, but the model is not able to apply useful syntactic information. The goal of joint models simultaneously reduce errors of POS tagging and dependency parsing tasks. In this research, we attempted to utilize the joint model on the Persian and English language using Corbit software. We optimized the model's features and improved its accuracy concurrently. Corbit software is an implementation of a transition-based approach for word segmentation, POS tagging and dependency parsing. In this research, the joint accuracy of POS tagging and dependency parsing over the test data on Persian, reached 85.59% for coarse-grained and 84.24% for fine-grained POS. Also, we attained 76.01% for coarse-grained and 74.34% for fine-grained POS on English