The backward crosstalk effect or response grouping in the psychological refractory period paradigm

Background: In the psychological refractory period paradigm, the second response time is increased as the interval between the first and second stimulus is decreased. The response delay for the second stimulus is called the psychological refractory period. In contrast with these findings, some evidence of the backward crosstalk effect has shown that the first reaction time is affected by the second stimulus. The capacity sharing models, in which multiple stimuli can be processed simultaneously, unlike central bottleneck models, are able to provide some explanations for the changes in the reaction time to the first stimulus. However, sometimes these changes could be arisen from response grouping; the first response remains on the processing buffer until the response to the second stimulus is prepared, then both stimuli are responded simultaneously. The questions of this study were whether the second task difficulty and time interval manipulation would affect the first task response or not and in what extend changes are because of response grouping? Materials and Methods: Detection, discrimination and choice tasks were used as the second task in the psychological refractory period paradigm and the time interval between stimuli was 50, 100, 200, 400, or 1000 ms. Results: The type of the second stimulus and time interval between stimuli had an effect on the second-task and first-task reaction times. Conclusion: In the detection group, the first task response time changes were consistent with grouping between the two responses, but in the discrimination group the changes would arise from capacity limitation and were consistent with the backward crosstalk effect

Comparison of biological factors of Aphanius sophiae in Cheshmeh-Ali of Damghan and Shour River of Eshtehard

Length, age frequency, von Bertalanfi growth parameter, reproduction and absolute fecundity of two populations of killifish (Aphanius sophiae) from Cheshmeh-Ali of Damghan and Shour River of Eshtehard were studied monthly from October 2004 to November 2005. There was no significant difference between sex ratios of the two populations (X^2.0.679, P=0.410). Age and length frequencies revealed that female fish of Cheshmeh-Ali were taller and longer-lived than those of Shour River. Maximum of gonadosomatic index of Cheshmeh-Ali fish was in May while in the case of Shour River, it was, in April. The absolute fecundity showed no significant difference using ANCOVA whereas egg diameter of Cheshmeh-Ali population was significantly bigger than Shour River population (P<0.001)

Gaussian mixture model-based contrast enhancement

In this study, a method for enhancing low-contrast images is proposed. This method, called Gaussian mixture model-based contrast enhancement (GMMCE), brings into play the Gaussian mixture modelling of histograms to model the content of the images. On the basis of the fact that each homogeneous area in natural images has a Gaussian-shaped histogram, it decomposes the narrow histogram of low-contrast images into a set of scaled and shifted Gaussians. The individual histograms are then stretched by increasing their variance parameters, and are diffused on the entire histogram by scattering their mean parameters, to build a broad version of the histogram. The number of Gaussians as well as their parameters are optimised to set up a Gaussian mixture modelling with lowest approximation error and highest similarity to the original histogram. Compared with the existing histogram-based methods, the experimental results show that the quality of GMMCE enhanced pictures are mostly consistent and outperform other benchmark methods. Additionally, the computational complexity analysis shows that GMMCE is a low-complexity method

Analysis of mitochondrial DNA sequences of Turcinoemacheilus genus (Nemacheilidae Cypriniformes) in Iran

Members of Nemacheilidae Family, Turcinoemacheilus genus were subjected to molecular phylogenetic analysis in this study. This genus was reported in 2009 to inhabit in Karoon River drainage, in contrary to previous assumption that it was the endemic species in the Basin of Tigris River. It was sampled from three stations placed in different tributaries in Karoon drainage and evaluated to understand the molecular phylogenetic relationships of Turcinoemacheilus in Iran. The mitochondrial cytochrome b gene (cyt b) and control region were used to infer phylogenetic relationships. PCR amplification of control region was not carried out successfully, possibly due to the high divergence of this sequence in the studied genus. The amplified fragments of cyt b were sequenced then analyzed by the use of phylogenetic software. Only one divergent position was seen in all three samples stations located in amino acid position 365. GTR and p-distances of cytochrome b gene for T. kosswigi computed from different stations of running water in Karoon drainage showed these samples belong to different populations and fall in intraspecific differences. In this study, examination of the molecular phylogeny using Bayesian analysis, maximum parsimony or neighbor-joining define the phylogentics of Turcinoemacheilus genus as a monophyletic clade which is sister-clade of Nemacheilus and Schistura genera. This report is the first report of Turcinoemacheilus molecular data and could describe molecular phylogeny of this genus in loaches

Morphometric and meristic study of Garra rufa populations in Tigris and Persian Gulf Basins

This study was conducted to determine morphometric and meristic characteristics of Garra rufa in 13 stations of Tigris and Persian Gulf basins. We caught 310 specimens during the year 2007-2008 using electro-shocker and sachok. Univariate analysis of variance (ANOVA) and principal component analysis were conducted and the ANOVA revealed significant differences in 28 morphometric and 9 meristic factors (P<0.05). Factor analysis showed that G. rufa of thirteen stations had 48.855% changes in 3 factors of the first morphometric characters (pectoral fin length, ventral fin length, depth of anal fin) and 71/611% changes in 3 factors of the first meristic characters (lateral line scales , circum peduncle scales, predorsal scales). Plotting the first and second principal component morphometric and meristic characters showed that the Mond River population was separated from the others but the other populations were overlapping with each other in the characteristics studied

Molecular assessment of Neospora caninum and Toxoplasma gondii in hooded crows (Corvus cornix) in Tehran, Iran

Abstract Neospora caninum and Toxoplasma gondii are two closely related protozoan parasites that have been detected from various species of bird hosts. However, little is known about the prevalence of N. caninum and T. gondii in crows. Hence, we examined the molecular frequency of N. caninum and T. gondii in the brain samples of hooded crows (Corvus cornix) that collected from different public parks of Tehran, Iran by nested-PCR method. We used the primers targeting the Nc5 and GRA6 genes for detection of N. caninum and T. gondii, respectively. From a total of 55 brain samples, 5 (9.9%) and 9 (16.36%) samples were positive for N. caninum and T. gondii, respectively. Sequencing of a N. caninum isolate revealed 95%–100% identity with the deposited N. caninum in GenBank. Genotyping of T. gondii isolates by PCR-RFLP analysis of the GRA6 gene revealed type III genotype in 8 isolates. The results of this study indicate that hooded crows may have a putative role in transmission of N. caninum and T. gondii to canines and felines definitive hosts, respectively

Sources of Sleep Disturbances and Psychological Strain for Hospital Staff Working during the COVID-19 Pandemic

Hospital staff members reported increased stress-related workload when caring for inpatients with COVID-19 (“frontline hospital staff members”). Here, we tested if depression, anxiety, and stress were associated with poor sleep and lower general health, and if social support mediated these associations. Furthermore, we compared current insomnia scores and general health scores with normative data. A total of 321 full-time frontline hospital staff members (mean age: 36.86; 58% females) took part in the study during the COVID-19 pandemic. They completed a series of questionnaires covering demographic and work-related information, symptoms of depression, anxiety, stress, social support, self-efficacy, and symptoms of insomnia and general health. Higher symptoms of depression, anxiety, and stress were associated with higher symptoms of insomnia and lower general health. Higher scores of depression, anxiety, and stress directly predicted higher insomnia scores and lower general health scores, while the indirect effect of social support was modest. Compared to normative data, full-time frontline hospital staff members had a 3.14 higher chance to complain about insomnia and a significantly lower general health. Symptoms of insomnia and general health were unrelated to age, job experience, educational level, and gender. Given this background, it appears that the working context had a lower impact on individuals’ well-being compared to individual characteristics

Evaluation of Run-Off Supply Projects in Hamadan Province (Iran)

ABSTRACT: Water resources project is for the control or use of water. Where utilization is proposed, the first question is usually how much water is needed .This is probably the most difficult of all the design problems to answer accurately because it involves social and economic aspect as well as engineering. In order to meet the various demands and of water requirements in Hamadan province which is situated in west of Iran, more than 28 projects were defined and studied, but only few of them were adopted. This paper presents a criteria based on the ratio of reservoir capacity to volume of earthen dam named as feasibility factor (F) for exact evaluation of different alternatives to assure the designer, so that, to obtain sufficient quantity of water in a form which can be easily and cheaply made fit for various uses

Hydrology and hydrobiology of Chaloos River

The Chaloos River originates from Alborz Mountain and enters into the Caspian Sea in Chaloos city. Five stations were chosen in different areas for the study during 1371 to 1372 (1992-93). Total variation range of hardness decreased 1 to 5 station, but measure NH4 and NO3 increased. 45 genera belongs to 4 phyla of phytoplankton as follows: Chrysophyta, Chlorophyta, Euglenophyta and Cyanophyta. Zooplankton existing in this river belong to animal classes, which had more abundance in Sarcodina and Monogononta. The benthos river establish Insecta larvae of Ephemeroptera, Coleoptera, Diptera, Plecoptera and Odonata (Orders). Chaloos fishes included to 4 families, 10 genera and 12 species. Cyprinidac consisted 66.7% of total fish and had maximum diversity at the various stations

Effect of human chorionic gonadotropin on sexual maturation, sex steroids and thyroid hormone levels in Caspian lamprey (Caspiomyzon wagneri Kessler, 1870)

The objective of this study was to determine the effect of human chorionic gonadotropin (hCG) on sexual maturation, plasma sex steroids [17β-estradiol, (E2) and 17α-hydroxy progesterone (17α_OHP)] and thyroid hormones (triiodothyronine, T3 and thyroxin, T4) levels in upstream - migrating Caspian lamprey. During the experiment, 36 fish (24 females and 12 males) in spring 2013 and 36 fish (24 females and 12 males) in fall 2013 were collected from the Shirud River estuary in Mazandaran Province, the Southern Caspian Sea during their upstream migration to the freshwater. All fish were injected with hCG at the doses of 1000, 1500 and 2000 IU.kg BW-1. The injection was a two - step process (50% of hormone in each step) by 12 h interval. After the first injection, fish were retained in the cages in the river beds and 24 hours after the second injection, fish were checked for egg and sperm release after mild abdomen pressure. Blood samples were taken for determining sex steroid levels. Results showed that hCG hormone injections caused increase in migration of germinal vesicle in the oocyte of female and sperm release in males. Significant differences were found in the serum E2 and 17α-OHP levels in hCG - injected fish compared to the control. However, no significant differences were found in serum T3 and T4 levels in the hCG -injected fish. According to the results, the appropriate hCG dosage to induce the reproduction acceleration in Caspian lamprey is 1500-2000 IU.kg BW-1