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

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

Short communication: A study of food consumption of the deepwater goby, Ponticola bathybius (Kessler, 1877), during spring migration in the southern Caspian Sea

The gobies exhibit a main role in the general production of the Caspian Sea due to their species diversity and unexploited stocks. So, of the 80 fish species known from Iranian part of the Caspian Sea, 10 of them are gobies. The deepwater goby, Ponticola bathybius (Kessler, 1877), Gobiidae, is a native species in the Caspian Sea which settles on sandy and shelly substrates and, in a few numbers, on firm silt down to 75 meters. The presence of predators such as Acipenseridae and prey items as Clupeonella sp. could be effective in the abundance of gobies. Gobies fishes are known as the great consumers of food resources and the considerable competitors for other species. ... In Iranian coastal waters of the Caspian Sea, there are differences in some important ecological factors including substrate type, slope and light intensity which may affect the prey community. Therefore, this study was carried out to compare dietary composition of P. bathybius at three different localities (Bandar-e-Anzali, Salmanshahr and Miankaleh) along the southern Caspian Sea coastal waters

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

A theoretical framework for determining environmental costs, benefits, and the net welfare effects associated with hazardous waste management

This paper reviews and presents a theoretical model to determine the costs, benefits, and welfare effects of hazardous wastes management. According to the Iranian law, environmental costs are assigned to waste producing firms. However, in practice, due to weak enforcement programs, firms do not pay any environmental costs. Using the basic principles and logic of welfare economics, we present a micro-level model for analyzing an industry that generates waste as a by-product of its production process. Firms in the industry choose the least cost method of disposal (either legal or illegal disposal). By utilizing various figures of presented models in partial equilibrium structure we found R'1, R'2 and 3 R′ which are the net welfare effect of producing firms, the net welfare effect to firms supplying legal waste disposal services and the net welfare effect of the environmental damage, respectively. By analyzing the presented figures we concluded that government regulatory policy may ideally lower environmental costs via a subsidy program

Comparison study on reproduction biology of mudskipper (Scartelaos tenuis) from Abi estuarie and Azini estuarie of Hormozgan Provience coastal area

Survey on fecundity of mudskipper Scartelaos tenuis from Abi Estuaries and Azini were carried out from March to April 2010. Data were sampled by hand based on simple random sampling. A totally 219 mudskipper were collected, throughout 113 individual were caught from Abi Estuaries (93 female, 20 male) and 106 invidiual from Azini Estuarie (83 femal, 23 male). The sex ratio of female to male was observed 1:0.24 and it was significantly different from the theoretical 1male:1female sex ratio (P>0.05). Mean total length were calculated 16.32±2.14 cm for female in Bandar Pol and 15.50±2.11 cm for male, and mean length 16.19±2.27 cm for femal and 17.26±1.9 cm for male in Tiab. The result showed no significant differences between mudskipper lengths in two areas (P>0.05). The more frequent length classes were calculated 15-16 cm in Bandar Pol and 18-19 cm in Tiab.The length – weight relationships were estimated as W= 0.0016TL2.7245 for female and W= 0.0138TL2.6523 for male, and the result showed isometric growth. Mean absolute fecundity were estimated 4147±1045 in Bandar pol and 3707±983 in Tiab area, there are no significant differences between fecundity in two areas (P>0.05). The relationship between fecundity-total length were calculated as Fecundity=36.17TL1.6412. The average eggs diameter were calculated 796±144mm in Bandar Pol and 737±137mm in Tiab. The relationship between egg diameter and gonad weight carried out as OD=0.0009GW-0.2167 (R2=0.4728)

Global, regional, and national burden of chronic kidney disease, 1990–2017 : a systematic analysis for the Global Burden of Disease Study 2017

Background Health system planning requires careful assessment of chronic kidney disease (CKD) epidemiology, but data for morbidity and mortality of this disease are scarce or non-existent in many countries. We estimated the global, regional, and national burden of CKD, as well as the burden of cardiovascular disease and gout attributable to impaired kidney function, for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017. We use the term CKD to refer to the morbidity and mortality that can be directly attributed to all stages of CKD, and we use the term impaired kidney function to refer to the additional risk of CKD from cardiovascular disease and gout. Methods The main data sources we used were published literature, vital registration systems, end-stage kidney disease registries, and household surveys. Estimates of CKD burden were produced using a Cause of Death Ensemble model and a Bayesian meta-regression analytical tool, and included incidence, prevalence, years lived with disability, mortality, years of life lost, and disability-adjusted life-years (DALYs). A comparative risk assessment approach was used to estimate the proportion of cardiovascular diseases and gout burden attributable to impaired kidney function. Findings Globally, in 2017, 1·2 million (95% uncertainty interval [UI] 1·2 to 1·3) people died from CKD. The global all-age mortality rate from CKD increased 41·5% (95% UI 35·2 to 46·5) between 1990 and 2017, although there was no significant change in the age-standardised mortality rate (2·8%, −1·5 to 6·3). In 2017, 697·5 million (95% UI 649·2 to 752·0) cases of all-stage CKD were recorded, for a global prevalence of 9·1% (8·5 to 9·8). The global all-age prevalence of CKD increased 29·3% (95% UI 26·4 to 32·6) since 1990, whereas the age-standardised prevalence remained stable (1·2%, −1·1 to 3·5). CKD resulted in 35·8 million (95% UI 33·7 to 38·0) DALYs in 2017, with diabetic nephropathy accounting for almost a third of DALYs. Most of the burden of CKD was concentrated in the three lowest quintiles of Socio-demographic Index (SDI). In several regions, particularly Oceania, sub-Saharan Africa, and Latin America, the burden of CKD was much higher than expected for the level of development, whereas the disease burden in western, eastern, and central sub-Saharan Africa, east Asia, south Asia, central and eastern Europe, Australasia, and western Europe was lower than expected. 1·4 million (95% UI 1·2 to 1·6) cardiovascular disease-related deaths and 25·3 million (22·2 to 28·9) cardiovascular disease DALYs were attributable to impaired kidney function. Interpretation Kidney disease has a major effect on global health, both as a direct cause of global morbidity and mortality and as an important risk factor for cardiovascular disease. CKD is largely preventable and treatable and deserves greater attention in global health policy decision making, particularly in locations with low and middle SDI

First record of Rhinogobius similis, Gill 1895 In Iran

This is the first record of Rhinogobius similis (Gobiidae), an exotic fish species in Iran. The results of this study show that a limited number of this species live in Harir-rud on Iran, Torkman Border. The morphometric and morphological characters of this species in Iran are similar to these from Japan and Korea

Mudskipper species diversity of the Khur-e-Abee protected area, Hormozgan Province

Mudskipper species diversity in the Khur-e-Abee protected area in the coastal areas of the Persian Gulf in Hormozgan Province was studied monthly. Sampling was done from March 2011 to February 2012 is 56º 24' 58” E, 27º 11' 28” N geographical position. A total of 730 specimens belonging to 3 species and 1 family werecollected by hand. Three species were identified; Boleophthalmus dussumieri, Scartelaos tenuis and Periophthalmus waltoni. The monthly sampling of mudskipper species composition showed that S. tenuis (45.75%), P. waltoni (30.48%) and B. dussumieri (26/02%) were first, second and the third in abundance respectively. Shannon species diversity index (1.09), Simpson index (0.62) and Pielou species index (0.99) were highest in October Whereas the Margalef species richness index (0.62) was the highest in December