The impacts of seasonal water discharge fluctuations on benthic communities on the productivity and the consumption of Tajan Estuary, southern coast of the Caspian Sea

In the present study, changes in benthic communities due to seasonal changes in the water of the southern Caspian Basin were investigated. Sampling was conducted monthly, from March 2006 to March 2007, at six selected stations in Tajan River mouth located on south eastern Caspian Sea. Also secondary benthic production consumable for fish and other biota inhabiting the mouth and adjacent areas were estimated. Forcing and limiting factors were also discussed. Benthic communities comprised 9 taxa, of which Balanus sp., Chironomus plumosus and Cerastoderma lamarki were the main contributors to both overall biomass and secondary production. Annual secondary production varied from 3.8g AFDWm-2 y-1, in the upper part of the mouth, to 78.06g AFDWm-2 y-1 in the center of the estuary area. Multivariate correlations between environmental variables and the macro benthic biomass highlighted the role of the water level, temperature, organic carbon content and dissolved oxygen which resulted in separation of communities in the estuary. Composition, biomass and secondary annual production of macro benthic communities were dramatically affected by changes in water residence time and summer drought crises. The isolation of this habitat limits the recovery of other benthic fauna during drought periods. Only populations of two taxa, Balanus sp. (Cirripeda) and C. plumosus (Diptera) seemed to be able to recover quickly after the drought crises, which, in turn, could compromise the overall secondary production, which may have negative effects on fish and other superior organism’s survival. During summer water renewal, when agricultural activities are intense, nutrient inputs should be regulated in this estuary to reduce the risk of benthic mass mortality and to ensure a sustainable ecosystem

Influence of Labratrema minimus (Trematoda: Digenea) on filtration rate performance of edible cockle Cerastoderma edule the extreme temperature and salinity conditions (an in vitro experiment)

In order to demonstrate filtration rate of edible cockle Cerastoderma edule under different salinity and temperature conditions, two groups namely healthy and infested with the parasite Labratrema minimus (Bucephallidae; Digenea) were compared. Results showed that the parasite-infested ones had difficulties in adaptation to the extreme conditions of salinity and temperature. Our results also showed that a healthy cockle could filter 78 ml min-1g-1 Flesh Dry Weight (FDW) seawater at 200e temperature and 34% salinity while an infested one processed 15.4 ml min-1g-1 FDW under the same conditions. In low salinity, which could happen during a rainy day and low tide, the healthy cockles processed 14.5 ml min-1g-1 FDW while infested cockles filtered 18.9 ml min-1g-1 FDW. Differences were not significant, however. Filtration rate of healthy cockles at a constant salinity but high temperature was 101.9 ml min-1g-1 FDW while the infested ones rated 27.2 ml min-1g-1 FDW. There was not a significant difference between their filtration rates at 20oC and 30oC. Our results showed that the parasite-infested cockles were unable to adapt to extreme conditions when an increase in temperature or a decrease in salinity occurred. If these results could be extrapolated to natural situations, the ecological cause of mortality due to parasites could be proved and explained

Investigating the Effects of Several Parameters on the Growth of Chlorella vulgaris Using Taguchi's Experimental Approach

Algae are part of photosynthetic organisms that play an important role in the aquatics nutrition. Like plants, algae need water, light and CO2 to grow. Using Taguchi's experimental approach (5 factors in four levels with 16 runs), effects of several parameters (NaCl, sodium bicarbonate and iron concentrations as well as light and temperature) on the growth of Chlorella vulgaris was studied. Increasing the concentrations of NaCl and sodium bicarbonate resulted in corresponding decreases in the growth of C. vulgaris. Media with 30.0g l-1NaCl did not indicate any algal growth. Also, with 9.0 g l-1sodium bicarbonate, biomass production was decreased. Chlorella vulgaris showed different growing behaviors at the various concentrations of iron (Fe+2) and at the different temperatures of this study. Maximum biomass production (approximately 3.56 g dry matter) was obtained at the 0.0 g l-1 sodium bicarbonate, 10.0g l-1NaCl, 18.0 µmol l-1 iron and at 30±2 °C. Yellow and blue lights increased the algal growth. Analysis of variance showed that salinity (i.e., the NaCl concentration) had the highest impact on the biomass production.

Influence of infestation by Labratrema minimus (Bucephalidae: Digenea) on oxygen consumption of edible cockle Cerastoderma edule (Mollusca: Bivalvia) in laboratory conditions

Short-term oxygen consumption and filtration rate experiments were conducted to evaluate the response of edible cockle Cerastoderma edule when infested by the Digenean trematod Labratrema minimus. In this experiment the metabolic activities of bivalves were measured to detennine this particular aspect of the host-parasite interaction. We have used the Bucephalidae digenea Labratrema minimus infestation as a factor which can alter the metabolic rates of its host: the edible cockle Cerastoderma edule from Arcachon bay (France). The results show that specific oxygen consumption of infested cockles decreases in comparison with that of healthy ones. This decrease in specific pumping rate is partly due to increase in the total cockle biomass measured, which is due to the presence of the parasite and can represent 20% of a healthy cockle's O2 consumption (it can constitute up to 92% of live mass in high infestation ii1tensities(personal observations; 1996) but consume little oxygen. In addition, the disease provoked by infestation can reduce the true metabolic activities. The results show that pumping rate is related to the intensity of the infestation with greater infestation associated with lower oxygen consumption. We also demonstrate that L. minimus is capable of oxygen consumption regulation. The consumption rate is maintained below 0.3 mmol O2 min-1 g-1 FDW (Fresh Dry Weight) in all external oxygen concentrations experimented

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

Evaluation of the Effect of Different Ferrule Designs on Fracture Resistance of Maxillary Incisors Restored with Bonded Posts and Cores

Introduction: In cases of severe hard tissue loss, 2 mm circumferential ferrule is difficult to achieve. So in these cases we should use different ferrule designs.This in vitro study investigated the effect of different ferrule designs on the fractureresistance of teeth restored with bonded post and cores.Materials and Methods: Forty freshly-extracted central incisors were endodontically treated. The teeth were randomly divided into four groups; group 1 were teeth with 2 mm circumferential ferrule above the CEJ, group 2 were teeth with 2 mm ferrule only on the palatal side of the teeth, group 3 consisted of teeth with 2 mm ferrule only on the facial side and group 4 were teeth with 2 mm ferrule on the palatal and facial side of teeth with interproximal concavities.All teeth were restored with fiber posts and composite cores. The specimen was mounted on a universal testing machine and compressive load was applied to the long axis of the specimen until failure occurred.Results: The fracture resistance was 533.79 ± 232.28 in group 1, 634.75± 133.35 in group 2, 828.90 ±118.27 in group 3 and 678.78± 160.20 in group 4. The post hoc analysis showed statistically significant difference between groups 1 and 3 .Conclusions: The results of this in vitro study showed that facial ferrule increases the fracture resistance of endodontically treated teeth restored with bonded post and cores

Impact of two parasitic trematodes, Meiogymnophallus minutus and Himasthla spp., on the growth of the cockle, Cerastoderma edule

The impact of two principal parasitic digenetic trematodes, Meiogymnophallus minutus and Himasthla spp., on the growth (weight and length) of the cockle, Cerastoderma edule, in Arcachon Bay (France) was studied. The experiment was conducted in the land-based mesocosms. The velocity of infestation with both trematodes was far more rapid during summer in the cockles already parasitized with these trematodes (0.35 to 0.45 metacercariae day-1) than those of healthy ones (approximately 0.01 metacercariae day-1). The parasitism had also an effect on the growth rates of cockles. During 190 days of the experiment, the daily growth speed varied from 0.001mm.da/ to 0.021mm.day-1. On average, the growth was slightly more important in healthy cockles after the start of experiments (0.014mm.day-1) than those initially infested cockles (0.011 mm.day-1). The experiment also showed that infestation of hosts with trematodes could perhaps disturb their immunity system, as the intensification with trematode parasites had been favored by already infested cockles

The comparison of psychological and social adaptation below elbow amputation men using a mechanical and myoelectric prosthesis by using of TAPES questionnaire

Design and manufacturing of the Myoelecterical prosthesis in compared to Mechanical prosthesis must also effectively, smart, light, strong and permanence. It is time consuming and expensive that ultimately leads to significant increases in the price of Myoelecterical prosthesis. Therefore, considering the high cost of these prostheses, hence, assessment of psychological and social adaptation between two groups must be clear and explicit. In this regards, present study was conducted on this topic. In this descriptive cross-sectional analytical study, two groups compared to each other from quality of life, participants was two groups of 20 below elbow amputation veterans that use from Mechanical or Myoelectrical prosthesis that refer to central technical orthopedic Kosar. For gathering the data we use TPEAS questionnaire. This questionnaire evaluates participants from 3 items: psychosocial adaptation, functional limitation and satisfaction of life. For data analysis use to t independent and ANOVA test. This research showed that there are significant differentiations in psychosocial adaptation between two groups. The findings identified that Myoelecterical group higher psychosocial and social adaptation in compare to Mechanical group. So that the hypothesis of this research in terms of higher psychological and social adaptation in the Myoelecterical group was accepted. Keyvani Hafshejani mA, Javanshir M, Kamali M., Ghasemi MS, Emami M, Esmaeeli SA, Langari A., Sattari Naeini M. The comparison of psychological and social adaptation below elbow amputation men using a mechanical and myoelectric prosthesis by using of TAPES questionnaire. Life Sci J 2012;9(4):5583-5587] (ISSN: 1097-8135). http://www.lifesciencesite.com. 82