674 research outputs found
Study of pathological effects of an organic germicide bathing on rainbow trout
The aim of this study was evaluation an organic germicide (Aquagerm) histological affects on Rainbow trout (Oncorhynchus mykiss) vital tissues. This new disinfectant is an aquatic antiseptic and mixed-oxidant disinfectant which is produced for the first time in Iran. This new product mechanism is based on oxidant properties of pro-sulphate which attack crucial structures of pathogens. In this study, forty healthy fish were selected and divided into two groups as control and treatment. The treatment group was treated with 1/2000 concentration of organic germicide for 45 min (according to the manufacturing protocols). At 4, 8, 12, 24, 48 and 96 h after bath challenge, 5 specimens were collected from treatment and one from control group. Gill, brain, kidney, and liver of all fish were sampled. Some histological damages such as edema and detachment of basic layer in secondary gill filaments were observed in gill microscopy results. The most important histological changes observed in the brain were congestion of some blood vessels. Furthermore, some evidences of increased melano-macrophage, glomerular shrinkage, and dilatation in Bowman capsules were recorded whereas no any damages were observed in liver. All histological changes removed after 48-96 h. It could be concluded that, all pathological observations in this study were just a natural response of fish body after exposing to the new disinfectant, and they were not recorded any damages like those which happen against hazardous chemicals. It seems that there is no risk associated with the consumption of this disinfectant for the fish tissues
The Effect of Using of TBLT on Vocabulary Learning by Deaf or Hard of Hearing Learners
The aim of the present study was to investigate the effect of Task-Based Language Teaching (TBLT) on the learning of new lexical items by Deaf and Hard of Hearing (DHH) learners. For this purpose, 30 beginner learners, studying English in the first grade of high school in two exceptional learners’ education centers in Yazd, Iran were selected. They were divided into two groups: experimental and control groups. The experimental group received Task Based Language Teaching (TBLT) treatment within which new lexical items were taught through different techniques based on form-focused task design. In the control group, the learners were learning the vocabulary items through the traditional method of Grammar Translation Method (GTM). Firstly a pre-test based on pictures was given to DHH learners. After 9 sessions of treatment, each lasted 30 minutes, a post-test was given to learners. T-test was used to analyze the data collected. The results showed that there was a significant difference between experimental and control groups. From different perspectives, the implication of this study can be discussed. This study can open an opportunity for teachers of DHH learners to experience some teaching methods not usually used in exceptional educational curriculum. Furthermore, these methods may be of high potentials for exceptional learners
Shear viscosity of superfluid 3He-A_1 at low temperatures
The shear viscosity tensor of the A_1-phase of superfluid 3He is calculated
at low temperatures and melting pressure, by using Boltzmann equation approach.
The two normal and superfluid components take part in elements of the shear
viscosity tensor differently. The interaction between normal and Bogoliubov
quasiparticles in the collision integrals is considered in the binary, decay
and coalescence processes. We show that the elements of the shear viscosities
, and are proportional to .
The constant of proportionality is in nearly good agreement with the
experimental results of Roobol et al.Comment: 16 pages, some typos were correcte
Genetic variability of rainbow trout (Oncorhynchus mykiss) cultured in Iran using molecular RAPD markers
In the present study we evaluated the amount and distribution of genetic variation by using RAPD marker variation of 12 markers loci in three broodstock groups of rainbow trout. A total of 47 polymorphic bands were observed in Iranian strain, average number of bands was 10 and average number of polymorphic bands per primer was 3.92. The total detected bands in rainbow trout strain originated from French, was 120 bands with an average number of 10 bands per RAPD primer. A total of 117 amplified were detected in Norwegian population, with an average number of bands and average number of polymorphic bands per primer was 9.75 and 2.58, respectively. Data for observed and effective number of alleles, Nei’s genetic diversity and Shannon’s information index for all the three populations were 1.31, 1.20, 0.120 and 0.170, respectively. The mean coefficient of gene differentiation value and the estimate of gene flow across the populations were found as 0.299 and 0.171, respectively. The Nei measures of genetic distance and identity between pairs of rainbow trout strains indicate that the strain originated from France and Iran has the highest genetic identity, while the fish originated from Norway and France showed the greatest genetic distance
The status of white spot syndrome virus (WSSV) in Islamic Republic of Iran
White spot syndrome virus (WSSV), the causative virus of disease, is found in most shrimp farming areas in Iran, and it causes large economic losses to the shrimp farming industry. Shrimp aquaculture is an important industry in Iran and plays an important role in aquaculture production. The shrimp production in 2012 was more than 12000 metric tonnes and it is estimated it will reach 20000 tonnes in 2013. White spot syndrome virus is highly virulent in shrimp farms and can spread quickly and cause up to 100% mortality within 3-7 days. The virus is a very large, enveloped, double stranded DNA (ds DNA) and assigned by ICTV to a new genus Whispovirus and belong to Nimaviridae family. In Iran WSSV first appeared in Khuzestan Province in the south of Iran, and later on it appeared in other provinces such as Bushehr, and Sistan and Baluchestan. The aim of this review is to give current information of WSSV in Iran, host ranges, carriers, biology, clinical signs, histopathology, PCR, with emphasis on the effects of WSSV in shrimp aquaculture
Chemotype of damask rose with oleic acid (9 octadecenoic acid) and its antimicrobial effectiveness
Essential oils are natural products that have great antimicrobial potential value against many fungi and bacteria. Rosa damascena Mill. is one of the most important aromatic species of the Rosaceae family from which essential oil and economically valuable products can be obtained. The present study was designed to investigate the major compositions of the essential oil of this plant in Isfahan region of Iran and to identify its antibacterial and antifungal effects against 11 microorganisms causing human diseases and food spoilage. The essential oil was extracted by using the Clevenger apparatus and was analyzed by gas chromatography-mass spectrometry (GC–MS) technique. Its antimicrobial activity was evaluated by well diffusion, minimum inhibitory concentration (MIC) and minimum bactericide concentration (MBC). The results showed that the most important compounds of the essential oil were nonadecane (24.72%), heneicosane (19.325%), oleic acid (17.63%), and citronellol (12.61%). The results also showed that the highest inhibition zone of rose essential oil was against Aspergillus brasiliensis (15.00 ± 0.00 mm) and had a significant effect on Klebsiella pneumoniae (~ 8.00 mm). Also the rose oil had a significant inhibition and lethal effect against Candida albicans (MIC and MBC ~ 125 μg/mL), which is equivalent to the nystatin antibiotic (~ 125 μg/mL). Therefore, the essential oil of Damask rose can be considered as an alternative natural product for the prevention and treatment of fungal diseases in humans and against food spoilage as well
SPHERIOUSLY? The challenges of estimating sphere radius non-invasively in the human brain from diffusion MRI
The Soma and Neurite Density Imaging (SANDI) three-compartment model was recently proposed to disentangle cylindrical and spherical geometries, attributed to neurite and soma compartments, respectively, in brain tissue. There are some recent advances in diffusion-weighted MRI signal encoding and analysis (including the use of multiple so-called ’b-tensor’ encodings and analysing the signal in the frequency-domain) that have not yet been applied in the context of SANDI. In this work, using: (i) ultra-strong gradients; (ii) a combination of linear, planar, and spherical b-tensor encodings; and (iii) analysing the signal in the frequency domain, three main challenges to robust estimation of sphere size were identified: First, the Rician noise floor in magnitude-reconstructed data biases estimates of sphere properties in a non-uniform fashion. It may cause overestimation or underestimation of the spherical compartment size and density. This can be partly ameliorated by accounting for the noise floor in the estimation routine. Second, even when using the strongest diffusion-encoding gradient strengths available for human MRI, there is an empirical lower bound on the spherical signal fraction and radius that can be detected and estimated robustly. For the experimental setup used here, the lower bound on the sphere signal fraction was approximately 10%. We employed two different ways of establishing the lower bound for spherical radius estimates in white matter. The first, examining power-law relationships between the DW-signal and diffusion weighting in empirical data, yielded a lower bound of , while the second, pure Monte Carlo simulations, yielded a lower limit of and in this low radii domain, there is little differentiation in signal attenuation. Third, if there is sensitivity to the transverse intra-cellular diffusivity in cylindrical structures, e.g., axons and cellular projections, then trying to disentangle two diffusion-time-dependencies using one experimental parameter (i.e., change in frequency-content of the encoding waveform) makes spherical radii estimates particularly challenging. We conclude that due to the aforementioned challenges spherical radii estimates may be biased when the corresponding sphere signal fraction is low, which must be considered
Determination of Tetanus Antibody Levels in Trauma Patients Referred To Shahid Beheshti Hospital in Kashan, Iran, 2014
Background: There is a noticeable difference in serologic immune status against tetanus among different age and social groups in various countries due to different national vaccination policies and methods.
Objectives: Considering that the immunization status of trauma patients against tetanus is not-known or uncertain and they may need to receive the vaccine and tetabulin, this study was conducted to determine the tetanus antibody levels in patients referred to the trauma emergency ward of Shahid Beheshti Hospital in Kashan City, Iran.
Patients and Methods: This cross-sectional study was performed on 204 trauma patients referred to the trauma emergency ward of Shahid Beheshti hospital in Kashan City, Iran, in 2014. After obtaining a written informed consent from the patients, a questionnaire consisted of demographic information and tetanus vaccination record was completed by the patients. Afterwards, a 4 - 5 mL venous blood sample was taken from each patient and the tetanus antibody level (IgG) was measured using the enzyme-linked immunosorbent assay method. The tetanus antibody levels equal or more than 0.1 IU/mL were considered protective. Data were analyzed using chi-square test, independent t-test and one-way ANOVA with SPSS software version 16.
Results: From a total of 204 patients, 35 cases (16.7%) were females and 169 (83.2%) were males with the mean age of 40.9 ± 3.7 years. There was no statistically significant difference in the tetanus antibody levels between both sexes (P = 0.09). Moreover, there was no significant difference in immunization status between the patients who had a history of tetanus vaccination and those who had not received the vaccine before (P = 0.67). The antibody levels were significantly reduced with the passage of time since the last vaccination (P < 0.001). Also, 87.3% of the patients had the high protective level of immunity to tetanus.
Conclusions: The findings of the present study show a high level of tetanus antibody among trauma patients in this hospital; so, taking the tetanus vaccine history can be misleading. It is suggested that further studies be performed in different regions of our country and with larger sample sizes and detection of the immunization status of patients by measuring anti-tetanus antibody levels among trauma patients is recommended to make suitable policy for a national vaccine protocol in the future
Antibiotic Resistance of Vibrio cholerae Isolates from Kashan, Iran
Aims: Cholera is an acute diarrheal disease that can lead to severe dehydration and death. Antibiotic resistance is a big challenge in infective disease like Cholera. The present study aimed to understand the characteristics and trends of antibiotic resistance of V. cholerae isolations in and around Kashan, Iran. Instrument & Methods: In this descriptive cross-sectional study, samples were gathered using census method from 1998 to 2013 in Kashan, Iran. 1132 fecal samples of patients with acute diarrhea and 237 samples of suspected water samples were taken. The serotypes and biotypes were determined by an enzymatic method. Antibiotic susceptibility test was performed by using Disk Diffusion Method. Data were analyzed using SPSS 23 software. Fisher-exact and Chi-square tests were used to compare the statistical parameters. Findings: 96 fecal samples (8.5) and 18 water samples (7.6) were positive for Vibrio cholerae. Non-agglutinating (Nag) isolates (75.4) were more common than serotype Inaba (13.2) and Ogawa (11.4). Nag serotypes were mostly resistant to cefixime (44) and ampicillin (33). In contaminated water samples also the most frequent cases were Nag serotype (50). Nag serotype showed 22.2 of resistance to ampicillin and nitrofurantoin. Conclusion: Vibrio cholerae isolates in Kashan, Iran, are highly resistant to antibiotics, especially Nag serotypes
Molecular Dynamic Simulation Model for the Growth of Thin Films in The Structure Zone Model
A two dimensional molecular dynamic (atomistic) simulation model was used to
investigate the relationship between the nano-structure and the deposition parameters; namely,
substrate temperature, deposition rate, angle of incidence, surface roughness. Qualitative
agreements with the predictions of the structure zone model (SZM) and the theoretical results
of Srolovitze and coworkers (1988), as well as expectations through changes in the activated
processes during film growth due to changes in deposition parameters (Grovenor and
coworkers (1984)) are obtained. It is shown that by enhancing the atomic mobility (i.e.,
increasing the substrate temperature or/and lowering the deposition rate) films of higher
density with fewer voids are produced. By increasing the deposition angle, the nano-structure
of the film changes from a dense film with few voids, to a nano-structure with
columns/boundless inclined with the same angle ( β ) towards the incidence atoms with
elongated voids. The angle β increases with increasing the deposition angle (α ), and in
agreement with the tangent rule (Dirks and Leamy (1977)). The angle of bundles (or the angle
of the formation of the voids between atomic bundles), and columnar structure are caused by
shadowing effects. Results showed that β decreases slowly with increasing surface mobility
(i.e., increasing the substrate temperature or/and reducing the deposition rate).
In general, the model provides almost all predicted results and agrees well with
observation
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