912 research outputs found

    Significant changes in pelagic fish stocks of Clupeonella spp. in the south Caspian Sea

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    The present study was carried out during 2006-2007 along the southern Caspian Sea. The species composition showed that the common kilka, Clupeonella cultriventris caspia, is dominant species with 89% and then anchovy, C. engrauliformis, has shown only 8.7% while it was already dominant species in the past decades. The overall results indicated that common kilka was replaced with anchovy kilka as previous dominant kilka species due to invasion of Mnemiopsis leidyi to the southern Caspian Sea. Anchovy suffered greatly from M. leidyi so that the total catch dropped from 95000 mt in 1999 to less than 20000 mt in 2007. In our survey, 1415 fish specimens were collected randomly, including 221 anchovy, 281 bigeye and 913 common kilka. The mean length of anchovy was 117.8 ± 0.27 mm, while it was about 93.0 mm during 1995 to 1998 before the invasion of M. leidyi. Analysis of age classes indicated the mean age of 4.5 ± 0.04 years for anchovy, 3.6 ± 0.03 for common kilka and 4.6 ± 0.08 for big eye C. grimmi. According to the age and the length structure of the specimens in this study, it could be concluded that in recent years, young fish population of anchovy has been decreased in comparison with the last decade. The results showed that some biological characteristics of kilka population were affected by M. leidyi. Recently fishing activities take place in shallow waters where schools of kilka are in suitable density for fishing. According to our results, ctenophore occupied the anchovy habitat where it was mainly more than 50 m depth. The fishing has moved to areas with depths less than 50 meters where it was the main reason to change in species composition

    A comparative study on reproduction of kilka species (Clupeidae) in southeastern parts of the Caspian Sea

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    The aim of the present study was to investigate the reproduction of three species of kilka, including common, anchovy and bigeye kilka in the southeastern waters of Caspian Sea. This study was conducted during 2010 and 6476 specimens were fortnightly collected from fishing landing site. Body weight and fork length were measured. The samples were dissected and female gonads were weighed. Sexual maturity classification was carried out based on six stages in ovarian development. Age was determined using sagitta otoliths. Results were compared with the previous years. Male: Female ratio in common, anchovy and bigeye kilka were 1: 0.779, 0.569: 1 and 0.656: 1, respectively. Study of sexual maturity stages and GSI showed that common kilka spawning began in March and ended in July with the peak in May. Spawning period of anchovy kilka was more extensive than common kilka and take place from April to November with a peak in November. Bigeye kilka spawned during the year entirely. Its spawning occurred intensively during the autumn with a peak in October. Our results showed that M: F ratio differs during the year which is related to their reproduction. The reproduction scheduling of kilka species comparing with the previous years had some changes but has not significantly been affected by the Caspian Sea pelagic changes

    Abundance and diversity of Clupeidae species in Mazandaran and Golestan coastal waters, north Iran

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    As part of the identification and distribution mapping of Clupeid fish in southern Caspian Sea, we studied abundance and species diversity of the fish in Mazandaran and Golestan Coastal waters during August-April 1999 to 2001. In the 336 specimens studied, four species were identified including Alosa braschnikowi, Alosa caspia, Alosa saposchnikowi and Alosa kessleri. The most abundant species was Alosa braschnikowii comprising 84.4% of the individuals and Alosa kessleri was the least abundant comprising 3.2% of the sample. We also traced an increasing trend in abundance of Alosa braschnikowii from east to west such that 43.8% of the fish found in Golestan Province waters and 56.2% in Mazandaran Province waters. The highest fork length and weight was recorded as 395 mm and 760.3 grams respectively for Alosa braschnikowi and the lowest was recorded for Alosa caspia with 110 mm and 109 grams respectively. In Alosa braschnikowi male were dominant and relative abundance of male and female in Mazandaran Province was 44.2% and 55.8% respectively. In Golestan, the relative male and female abundance of Alosa braschnikowi was 30.6% and 69.4% respectively. Female to male sex ratio in the A. braschnikowi was 1:1.26 and 1:2.26 respectively in Mazandaran and Golestan provinces. Overall female to male sex ratio was calculated as 1:1.6 for the species. The caught A. braschnikowi were in I+ to 6+ age groups with the 2+ group comprising 28.9% and 1+ and 6+ comprising 8.9% of the sample

    An objective evaluation method for rehabilitation exergames

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    The aim of this work is to objectively evaluate the performance of patients using a virtual rehabilitation system called MIRA. MIRA is a software platform which converts conventional therapeutic exercises into games, enabling the user to practice the given exercise by playing a game. The system includes a motion sensor to track and capture user's movements. Our assessment of the performance quality is based on the recorded trajectories of the human skeleton joints. We employ two different machine learning approaches, dynamic time warping (DTW) and hidden Markov modeling (HMM), both widely used for gesture recognition, to compare the user's performance with that of a reference as ground truth

    Validation of back-calculation methods using otoliths to determine the length of anchovy kilka (Clupeonella engrauliformis)

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    Age structure of the Caspian Sea anchovy kilka, Clupeonella engrauliformis, was estimated for the first time by back-calculation methods. Otolith growth and the rate of increment in anchovy kilka were examined to determine whether otoliths could be used to back calculate body sizes at various life stages. Sampling was carried out on commercial fishing vessels board along the Iranian coast in 2007. The age structure of the samples ranged from 2 to 7 years old which was dominated by the third year class (38.6%). The largest fish measured was 137.2mm fork length. The relationship between fork length (FL) and otolith radius (OR) was described by the following equation: FL=13.77+ 82.78*OR (r^2=0.92). Three proportional back-calculation methods, Fraser-Lee, Whitney & Carlander and Dahl-Lea models, were compared by using data sets of anchovy kilka otoliths, and we validated back calculation by comparing them with observed lengths. Back calculated lengths generally corresponded well with observed lengths in anchovy kilka age classes. Variance of the back calculated length data obtained from three models indicated no significant difference (P>0.05)

    Detection of Toxoplasma gondii in Raw Caprine, Ovine, Buffalo, Bovine, and Camel Milk Using Cell Cultivation, Cat Bioassay, Capture ELISA, and PCR Methods in Iran

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    This study was conducted to determine the presence of Toxoplasma gondii in animal milk samples in Iran. From a total of 395 dairy herds in three provinces of Iran, 66 bovine, 58 ovine, 54 caprine, 33 buffalo, and 30 camel herds were studied, and from these parts of Iran, 200 bovine, 185 ovine, 180 caprine, 164 buffalo, and 160 camel milk samples were collected from various seasons. Samples were tested for Toxoplasma gondii by cell line culture, enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR) technique. Only the results of cell line cultivation were confirmed by bioassay in cat. Results indicated that all herds were infected with Toxoplasma gondii. The culture method showed that 51 out of 889 milk samples (5.73%) were positive for Toxoplasma gondii, and all 51 positive culture results were positive with bioassay in cat. The Fars province had the highest prevalence of Toxoplasma gondii (6.84%). The ELISA test showed that 41 milk samples (4.61%) were positive for the presence of Toxoplasma gondii, while the PCR showed that 46 milk samples were positive for Toxoplasma gondii. The results showed higher sensitivity of PCR and higher specificity of ELISA. Caprine had the highest (10%) and camel had the lowest (3.12%) prevalence rate of parasite. The summer season had the highest (76.47%) but winter (3.92) had the lowest incidence of Toxoplasma gondii. This study is the first prevalence report of direct detection of Toxoplasma gondii in animal milk samples in Iran

    DESCRIPTION OF UTI IN PATIENTS WITH RENAL TRANSPLANTATION ADMITTED IN LABAFINEGAD HOSPITAL FROM 1384 TO 1385

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    Background: The renal transplantation is now the treatment of choice for ESRD. Urinary tract is the most common site for infection after kidney transplantation. The different clinical & microbiological aspects of UTl in renal transplantation. Materials and Methods: In this cross- sectional study, the clinical manifestation at the time of admission, past medical history, the time of transplantation & the result of laboratory data including U/A, U/C & CBC of patients with kidney transplantation & probable UTl were collected & analysed in SPSS 11.5. ..

    Stock assessment of Acipenser persicus in the southern Caspian Sea, 2008-2009

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    Species composition, relative abundance, absolute abundance and biomass of sturgeon species were studied during the years 2008-2009. Eighty five stations were covered in the stratified random sampling design in depths less than 10m using 9m bottom trawl (head line) and in depths more than 10m using 24.7m bottom trawl (head line). More than 70 specimens of Acipenser persicus were caught during the effort. CPUE decreased from 0.4 to 0.24 specimens per trawl in 2009. The mean total length of the A. persicus was 47.3 ±29.1cm and 61.9 ±28.7cm in 2008 to 2009, respectively. The smallest size of A. persicus was 9cm in 2008 and 24.5cm in 2009, while the maximum size was 102.5cm in 2008 and 126.5 ±29cm in 2009. The mean total weight in 2009 in comparison with 2008 increased from 989(3-5000g) to 1569(42-7100g). Absolute abundance of A. persicus decreased from 2006000 specimens in 2008 to 1192000 specimens in 2009. The estimated biomass was 2010 and 1878 tons in 2008 and 2009, respectively. According to the results of study, the stock status of A. persicus is highly critical in the Caspian Sea and a timely decision has to be taken for conservation of the species

    Photo-Catalytic Activity of ZnO Supported on H-ZSM-5 Zeolite to Reduce Cr(VI) from Aqueous Solutions

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    Abstract Aims: The application of photocatalytic processes to remove heavy metals in aqueous solutions and industrial wastewater are regarded as extremely effective, clean and without producing waste methods. The goal of the present study was to investigate the photocatalytic activity of ZnO based on H-ZSM-5 zeolite support. Materials & Methods: ZnO/H-ZSM-5 composite synthesized by impregnation method successfully, and photo-reduction of Cr(VI) was investigated via this composite in present of UV light irradiation. The prepared composite was characterized by X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). Data was analyzed by repeated measurement statistical test. Findings: ZnO/H-ZSM-5 (79.5) had better removal photo-reduction activity than pure H-ZSM-5 (8.7; p=0.003) zeolite and ZnO (58.8; p=0.003). The initial concentration of Cr(VI) was a highly influential factor in photo-reduction of Cr(VI); In the way that when the initial concentration increased from 10 to 40mg/l, the photo-reduction percentage decreased from 92.5 to 57.7 in constant operational conditions (p=0.001). Conclusion: ZnO/H-ZSM-5 composite has higher removal photo-catalytic activity than pure ZnO and HZSM-5 zeolite. Photo-reduction of Cr(VI) by ZnO/H-ZSM-5 composite is an efficient technology for the treatment of water and wastewater containing high concentration of Cr(VI)
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