String Memory Effect

In systems with local gauge symmetries, the memory effect corresponds to traces inscribed on a suitable probe when a pure gauge configuration at infinite past dynamically evolves to another pure gauge configuration at infinite future. In this work, we study the memory effect of 2-form gauge fields which is probed by strings. We discuss the "string memory effect" for closed and open strings at classical and quantum levels. The closed string memory is encoded in the internal excited modes of the string, and in the open string case, it is encoded in the relative position of the two endpoints and the noncommutativity parameter associated with the D-brane where the open string endpoints are attached. We also discuss 2-form memory with D-brane probes using boundary state formulation and, the relation between string memory and 2-form soft charges analyzed in [1]

Head circumference in Iranian infants

Background: Head circumference (HC) measurement is an important parameter in the diagnosis of neurological and developmental disorders as well as dysmorphic syndromes. Recognition of different disorders requires an understanding of the normal variation of the HC size, especially during infancy which is a period of rapid brain growth. Regarding the differences in the international and interracial standard charts of anthropometric indices, local and generational diversities, changes in the ethnic mix of the population and socioeconomic factors, periodic re-evaluations need to be done on the size of HC. This study aimed to represent a local HC standard for an Iranian infant population in comparison with the charts of the American National Center of Health Statistics (NCHS) approved by the World Health Organization (WHO). Methods: About 1003 neonates were randomly enrolled in this cross-sectional study. They were ageing from 3 days to 24 months and were apparently in normal condition. The HC size of these infants was measured and recorded. Tables and graphs were diagramed by Excel Microsoft Office 2007 software and two-tailed Student's t-test was used for statistical analysis of data. Results: According to the findings of this study, the mean of the HC size in male infants was larger than the female ones. Based on a visual comparison, the curves followed a pattern similar to that of the NCHS's. Overall, our subjects in both genders were found to have a smaller HC size at birth compared to the NCHS charts. However, infants of other ages had a larger HC size compared to that of the NCHS's. Conclusion: With respect to the international and interracial differences in the HC size, it is recommended that local anthropometric indices be constructed and used clinically across the world. In addition, extensive and longitudinally designed studies are required in this regard

Creation and promotion Iranian fisheries research institute laboratories database

Creating a database of affiliated laboratories of the institute is organized with the aim of integrating information related to laboratories of research centers and their subsidiaries. The main objective of conducting this project in this stage is to upgrade it, establish and run one software system based on up-to-date networking technology. For this purpose organizing the centers database, a periodic report on various aspects can be done which help for implementing appropriate monitoring and management. Among the sectors that are designed and upgraded for this system include: Portal, information bank, advanced possibilities for inputting data, searching and reporting on laboratory. The advantages of this precise and updated reports can be collected easily from the general information of research institutes and centers, reports of the number of lab experts with different educational levels in affiliated centers, awareness of numbers and status of the chemical materials in the laboratories of each center, and the significant and important point is about economizing equipment, chemical materials and on time calibration

Bilateral Intraosseous Migration of Mandibular Second Premolars in a Patient with Nine Missing Teeth

Intraosseous migration is an unusual developmental dental anomaly, which demonstrates horizontal movement of unerupted teeth only affecting the permanent dentition of the lower jaw. Mandibular second premolar is the most common impacted tooth after the third molars and maxillary canines. Distal migration of the second premolar is rare and early loss of the permanent first molar is one of the most important predisposing factors of intrabony migration of this tooth. Bilateral migration of the mandibular premolars is very rare compared to unilateral migration. Hereby, we present an 18-year-old man with bilateral intrabony migration of the mandibular second premolars to the mandibular angle (at the inferior and buccal side of the mandibular canal) in the presence of first molars. The patient also had nine congenitally missing teeth without any systemic complication or abnormality in the skeleton. The teeth were surgically extracted. The clinical and diagnostic features and treatment of this case are discussed

Neuronal Correlates of Tactile Working Memory in Prefrontal and Vibrissal Somatosensory Cortex

Tactile working memory engages a broad network of cortical regions in primates. To assess whether the conclusions drawn from primates apply to rodents, we examined the vibrissal primary somatosensory cortex (vS1) and the prelimbic cortex (PL) in a delayed comparison task. Rats compared the speeds of two vibrissal vibrations, stimulus1 and stimulus2, separated by a delay of 2 s. Neuronal firing rates in vS1 and PL encode both stimuli in real time. Across the delay, the stimulus1 representation declines more precipitously in vS1 than in PL. Theta-band local field potential (LFP) coherence between vS1 and PL peaks at trial onset and remains elevated during the interstimulus interval; simultaneously, vS1 spikes become phase locked to PL LFP. Phase locking is stronger on correct (versus error) trials. Tactile working memory in rats appears to be mediated by a posterior (vS1) to anterior (PL) flow of information, with performance facilitated through coherent LFP oscillation

Short communication: Infection of Aphanius dispar (Holly, 1929) with Ligula intestinalis plerocercoids in Mehran River, Hormuzgan province, south of Iran

Aphanius dispar (Holly, 1929) (known as Mahi gour-e khari, mahi dom parchami, kopurdandandar-e balehbolband) is an euryhaline tooth-carp fish which apparently prefers brackish waters of coastal areas of Iran. It is also distributed in Cyprus, Iraq, Somalia, Israel, Saudi Arabia, Syria and Djibouti. Aphanius dispar occurs in shallow water and among vegetation over sand, rock or soft detritus bottoms. Ligula intestinalis (L., 1758) is a pseudophyllidean cestode which in its plerocercoid stage infects a range of freshwater fish species, particularly members of the cyprinidae, as its second intermediate host and it has a widespread distribution throughout the northern hemisphere. However, no report is available on the occurrence of L. intestinalis from tooth-carp fish found in southern Iran. Recently, the present authors studied the infection of A. persicus in Barme-e-Shoor Spring-Stream System, Maharlu Basin, Shiraz, Iran. The present study was undertaken to investigate the possibility of A. dispar acting as an intermediate host for Ligula intestinalis from Mehran river in Mehran basin, near Bastak city, Hormuzgan Province, south of Iran

Histomorphometrical study of gonads in the endemic cyprinid fish, Cyprinion tenuiradius Heckel, 1847 (Cypriniformes: Cyprinidae)

To describe the morphological and histological changes during the annual reproductive cycle of the gonads of Cyprinion tenuiradius, a total of 341 specimens (102 female and 235 male specimens) were collected monthly from the Rudbal River (in the Qarah Aghaj sub-basin, the Persian Gulf basin), Firuzabad, Fars Province, southern Iran. The randomly sampling was adequate to collect males and females at the immature, mature, spawning-active, and non-active phases of reproduction. Five ovarian and five testicular maturation stages (I–V) were described using macroscopic and light and electron microscopic criteria. Also based on the histological examination, six types of ovarian follicles (A-F) and five types of testicular cells were designated. The largest ovarian follicles were found in the stage V of ovarian developmental stages in females with mean body weight and standard length of 22.27 g and 95.13 mm, respectively. The highest number of sperms was observed in the stage V of testicular developmental stages in males with mean body weight of 25.67 g and mean standard length of 97.83 mm. Based on the percentage of late ovary and testis maturation stages (IV, V) and high frequency of large oocytes and sperms it was concluded that the Qarah Aghaj botak spawns once a year during spring and the beginning of summer from April to July

Isolation and identification of Flavobacterium columnaris like organisms from grass carp (Ctenopharyngodon idella) and assessment of its histopathological effects in Khouzestan Province, Southern Iran

Following a mortality of up to 40% of cultured Grass Carp (Ctenopharyngodon idella) in fish farms of Khouzestan province when water temperature was up to 20°C, samples were taken and examined for etiological clues. We observed that fish gills were coated with a gray-white mucus layer, fin was eroded and wounds were present in peduncle of the affected samples. Bacteriological studies on the samples of gills and eroded and wounded peduncle skin using Cytophaga selective medium, resulted in isolation of filamentous gram negative bacteria chemically similar to Flavobacterium columnaris. Histological observations showed the affected fish carrying symptoms including congestion, hemorrhagia, edema in base membrane, hyperplasia of chondrocyte and secondary lamellae cells, fusion of lamellae, necrosis and peeling of secondary lamellae and also presence of filamentous bacteria in gill tissue sections. Necrosis of skin layers and expansion of ulcer to underlying muscles, degeneration of muscle cells and necrosis of muscle bundles were seen in peduncle muscles. We did not find this bacterium in internal organs. We conclude that the isolation of the bacterium and observation of histo-pathological changes suggest the organisms may be considered as a primary or secondary factor in occurrence of the disease

Differentiation of embryonal carcinoma stem cells into insulin-producing cells by using pancreas extract in vitro

Introduction: Type I diabetes mellitus results from the autoimmune destruction of the β cells in pancreatic islets. Currently, extensive research is being conducted on the generation of insulin-producing cells (IPCs) from stem cells. P19 embryonal carcinoma cells are multipotent and can differentiate into cell types of all three germ layers. In this study, the differentiation of P19 cells into IPCs by using mouse pancreas extract (MPE) was investigated. Materials and Methods: Embryoid bodies (EBs) obtained from P19 cells were cultured in medium containing 3 fetal bovine serum, supplemented by concentration of 50, 100, 200,300 μg/mL MPE for 7-14 days. Dithizone (DTZ) staining was used to detect IPCs derived from EBs in vitro. Mouse monoclonal insulin-proinsulin and monoclonal insulin receptor beta antibodies were used for immunoflourescence. Insulin content from the cells and insulin secreted by differentiated cells in response to concentrations of 5.5 and 25 mM glucose were measured using ELISA kits. Results: DTZ-positive cells showed purple-red clusters. immunoflourescence indicated expression of Beta cell markers (insulin-proinsulin and insulin receptor beta) in these cells. Increasing glucose concentration, caused more insulin to be secreted by differentiated cells. Conclusions: P19 cells can in the presence of pancreas extract differentiate to cell producing and secreting insulin cells. Differentiated cells can increase insulin secretion in response to increasing glucose medium