248 research outputs found

    Seroprevalence of toxocariasis in children aged 1-9 years in western Islamic Republic of Iran, 2003

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    We determined the seroprevalence of Toxocara canis infection in 544 children under 10 years randomly selected from urban and rural areas of Hamadan, An enzyme-linked immunosorbent assay was used for detection of antibodies to T. canis excretion - secretion antigens. Using a questionnaire, epidemiological factors associated with infection were examined, including age, sex, residence. Antibodies to T. canis were detected in 29 children (5.3%) and 19 children (3.5%) were categorized as borderline positive; thus together this gave a prevalence of toxocariasis of 8.8%. No significant differences were found in terms of sex, age and residence

    Molecular variation in Leishmania parasites from sandflies species of a zoonotic cutaneous leishmaniasis in northeast of Iran

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    Background & objectives: In the well-known zoonotic cutaneous leishmaniasis (ZCL) focus in Turkmen Sahara, border of Iran and Turkmenistan, ZCL has increased among humans in the past five years. The present study was undertaken to incriminate vectors of ZCL in the region, and to find molecular variation in Leishmania parasites. Methods: The sandflies were sampled using CDC light-traps and sticky papers. All the sandflies were identified using morphological characters of the head and abdominal terminalia. DNA was extracted from the dissected thorax and attached anterior abdomen of individual female sandfly. Leishmania detection and identification of sandflies were performed using PCR, digestion of BsuRI restriction enzyme and sequencing of ITS-rDNA gene and also by semi-nested PCR to amplify minicircle kinetoplast (k) DNA of Leishmania. Results: Leishmania infections were detected in 26 out of 206 female sandflies. Of the infected sandflies, 18 were Phlebotomus papatasi while eight were P. caucasicus/P. mongolensis. Two infections of L. turnica were detected, one in P. papatasi and other in P. caucasicus/P. mongolensis and the rest of the sandflies were found infected with L. major. Conclusion: Our finding showed that L. major had low diversity with only one common haplotype (GenBank Access No. EF413075). The novel haplotypes were discovered in L. major (GenBank Access No. KF152937) and in L. turanica (GenBank Access No. EF413079) in low frequency. These Leishmania parasites are circulating to maintain infections in the P. papatasi and P. caucasicus/P. mongolensis in Turkmen Sahara

    Association between Endothelial Selectin (E-selectin) gene polymorphisms and E-selectin level with visceral leishmaniais, in an ARMS-PCR based study

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    Background: In the visceral leishmaniasis (VL), parasites reside in reticuluendothelial system, mainly in macrophages. Endothelial Selectin (E-selectin) might play an important role in leukocyte-endothelium interactions and inflammatory cell recruitment. The aim of this study was determining E-selectin level and its polymorphism in three groups, patients, seropositive and healthy individuals. Methods: Serum soluble E-selectin levels as well as 2 polymorphisms of E-selectin (Ser128Arg and Leu554Phe) were measured in a cohort of patients with documented VL (n=64), a healthy control group (n=74) and a seropositive for VL but without any symptoms (n=81). Circulation concentration of E-selectin levels was measured by ELIS. The amplification refractory mutation system (ARMS)-PCR procedure was used for detecting polymorphisms. Results: The mean of E-selectin levels significantly differed between three groups (P<0.026), and were increased in patients in comparison with other groups. Difference was more considerable between two groups of patients and healthy ones (patients 92.8 ng/ml; healthy individuals 71.9 ng/ml). Polymorphisms were associated with soluble E-selectin levels and altogether explained 14.4%, 7.2%, and 8.7% in patients, seropositive and seronegative healthy individuals, respectively. Distribution of polymorphisms of 128Ser/Arg and 554Leu/Phe among three groups was not different significantly; however, there was a considerable arrangement in distribution of Ser128Arg polymorphism and 128Arg allele in healthy group was more than two fold of patients (55% against 20%). Conclusion: The association between soluble E-selectin levels and visceral leishmaniasis suggests that this molecule might have significant role in the inflammatory process in VL. Moreover, frequency of 128Arg allele in healthy group was higher than patients

    Anthropometric indices in individuals infected with ascaris lumbericoids in Iran

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    Context: Ascaris Lumbericoids infection is more common in children and teenagers and in areas with poor sanitation or crowded living conditions. Largest of all the parasites inhabiting the human intestine it is also the most common of parasitic infections in developing countries. It has been reported to infect about one-fourth of the world population. Chronic ascariasis has been reported to adversely effect the growth rate and anthropometric indices in infected individuals of growing age. Aims: The goal of this research was to evaluate the anthropometric indices in individuals infected with Ascaris in Hamedan province of Iran. Settings and Design: This was a descriptive cross sectional study. Methods and Material: Six hundred fourteen randomly selected individuals who were inhabitants of Hamedan province of Iran were chosen for this study. Stool samples of these individuals were collected and then experimented with Formel-Ether method to determine Ascaris Lumbericoids infection. Height and weight of these individuals were measured and compared with the indices related to NCHS. Demographic information of these individuals was entered into questionnaires and ultimately was analyzed with SPSS software. Results: Out of the total study population, 16.5% of individuals were found to be infected with Ascaris. Out of the individuals infected with Ascaris, 1% were underweight. In the age groups of 6-10, 11-15, 16-20 years, 3.5%, 5.1% and 3.5% were found to be suffering from malnutrition, respectively. Conclusion: Malabsorption in children might result in malnutrition. In this study, few individuals infected with Ascaris had malnutrition, thus Ascaris infection may not be an important cause of malnutrition among children in our area

    Awareness and prevalence of industrialized building system (IBS) in Iran

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    The introduction of modern technologies and development of building systems has influenced a fundamental transformation in many aspects of construction industry. However, still in major parts of building projects, conventional methods are being used in Iran. Traditional methods cause many problems such as project prolongation, low economic efficiency, too much stuff, and low quality of products. These shortcomings are more tangible in large-scale housing projects that require a vast domain of constructions; therefore, transformation from the current conventional building systems to the industrialized building systems (IBS) is needed more than ever. In order to this transformation it is vital that first the perceptions of the industry on these issues are adequately studied in this research. According to the lack of strategic plans and effective measures to promote IBS at country level, in addition to introducing the level of awareness and familiarity to IBS technical knowledge, the prevalence of both IBS components implementation and using IBS in different type of projects in Iran conducted. A Likert based questionnaire was designed according to the level of awareness and the prevalence of IBS was evaluated applying the mean index and average ranking method. Consistent with this study, only 2% of respondents are fully familiar with IBS and approximately 95% of respondents does not have acceptable awareness of this construction method. The average index of prefabricated components prevalence in Iran is 2.72 and sandwich panel is the most prevalent IBS components by mean index of 3.42. In other side, the estimation of the mean index of IBS method prevalence in different types of projects in Iran is 2.69 and marine structures are the most prevalent project type that is performed using IBS with the mean index of 3.89. Accordingly, the results indicate that the prevalence of IBS in terms of components and types of projects is not at significant level. This research examines the key suggestions to encourage IBS usage in Iran and the mandatory use of prefabricated systems by government is the best solution for IBS promotion by mean index of 3.96. This paper provides an overview of IBS current state in Iran. Clearly, this awareness will prompt construction industry practitioners to a deeper exchange of ideas and promoting IBS in the future

    Deep-FS: a feature selection algorithm for deep Boltzmann machines

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    A Deep Boltzmann Machine is a model of a Deep Neural Network formed from multiple layers of neurons with nonlinear activation functions. The structure of a Deep Boltzmann Machine enables it to learn very complex relationships between features and facilitates advanced performance in learning of high-level representation of features, compared to conventional Artificial Neural Networks. Feature selection at the input level of Deep Neural Networks has not been well studied, despite its importance in reducing the input features processed by the deep learning model, which facilitates understanding of the data. This paper proposes a novel algorithm, Deep Feature Selection (Deep-FS), which is capable of removing irrelevant features from large datasets in order to reduce the number of inputs which are modelled during the learning process. The proposed Deep-FS algorithm utilizes a Deep Boltzmann Machine, and uses knowledge which is acquired during training to remove features at the beginning of the learning process. Reducing inputs is important because it prevents the network from learning the associations between the irrelevant features which negatively impact on the acquired knowledge of the network about the overall distribution of the data. The Deep-FS method embeds feature selection in a Restricted Boltzmann Machine which is used for training a Deep Boltzmann Machine. The generative property of the Restricted Boltzmann Machine is used to reconstruct eliminated features and calculate reconstructed errors, in order to evaluate the impact of eliminating features. The performance of the proposed approach was evaluated with experiments conducted using the MNIST, MIR-Flickr, GISETTE, MADELON and PANCAN datasets. The results revealed that the proposed Deep-FS method enables improved feature selection without loss of accuracy on the MIR-Flickr dataset, where Deep-FS reduced the number of input features by removing 775 features without reduction in performance. With regards to the MNIST dataset, Deep-FS reduced the number of input features by more than 45%; it reduced the network error from 0.97% to 0.90%, and also reduced processing and classification time by more than 5.5%. Additionally, when compared to classical feature selection methods, Deep-FS returned higher accuracy. The experimental results on GISETTE, MADELON and PANCAN showed that Deep-FS reduced 81%, 57% and 77% of the number of input features, respectively. Moreover, the proposed feature selection method reduced the classifier training time by 82%, 70% and 85% on GISETTE, MADELON and PANCAN datasets, respectively. Experiments with various datasets, comprising a large number of features and samples, revealed that the proposed Deep-FS algorithm overcomes the main limitations of classical feature selection algorithms. More specifically, most classical methods require, as a prerequisite, a pre-specified number of features to retain, however in Deep-FS this number is identified automatically. Deep-FS performs the feature selection task faster than classical feature selection algorithms which makes it suitable for deep learning tasks. In addition, Deep-FS is suitable for finding features in large and big datasets which are normally stored in data batches for faster and more efficient processing

    A supervised learning algorithm for learning precise timing of multiple spikes in multilayer spiking neural networks

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    There is a biological evidence to prove information is coded through precise timing of spikes in the brain. However, training a population of spiking neurons in a multilayer network to fire at multiple precise times remains a challenging task. Delay learning and the effect of a delay on weight learning in a spiking neural network (SNN) have not been investigated thoroughly. This paper proposes a novel biologically plausible supervised learning algorithm for learning precisely timed multiple spikes in a multilayer SNNs. Based on the spike-timing-dependent plasticity learning rule, the proposed learning method trains an SNN through the synergy between weight and delay learning. The weights of the hidden and output neurons are adjusted in parallel. The proposed learning method captures the contribution of synaptic delays to the learning of synaptic weights. Interaction between different layers of the network is realized through biofeedback signals sent by the output neurons. The trained SNN is used for the classification of spatiotemporal input patterns. The proposed learning method also trains the spiking network not to fire spikes at undesired times which contribute to misclassification. Experimental evaluation on benchmark data sets from the UCI machine learning repository shows that the proposed method has comparable results with classical rate-based methods such as deep belief network and the autoencoder models. Moreover, the proposed method can achieve higher classification accuracies than single layer and a similar multilayer SNN

    Fumonisin B1 contamination of cereals and risk of esophageal cancer in a high risk area in Northeastern Iran

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    Introduction: Fumonisin B1 (FB1) is a toxic and carcinogenic mycotoxin produced in cereals due to fungal infection. This study was conducted to determine FB1 contamination of rice and corn samples and its relationship with the rate of esophageal cancer (EC) in a high risk area in northeastern Iran. Methods: In total, 66 rice and 66 corn samples were collected from 22 geographical subdivisions of Golestan province of Iran. The levels of FB1 were measured for each subdivision by thin layer and high pressure liquid chromatographies. The mean level of FB1 and the proportions of FB1 contaminated samples were compared between low and high EC-risk areas of the province. Results: The mean of FB1 levels in corn and rice samples were 223.64 and 21.59 μ/g, respectively. FB1 contamination was found in 50% and 40.9% of corn and rice samples, respectively. FB1 level was significantly higher in rice samples obtained from high EC-risk area (43.8 μ/g) than those obtained from low risk area (8.93 μ/g) (p-value=0.01). The proportion of FBI contaminated rice samples was also significantly greater in high (75%) than low (21.4%) EC-risk areas (p-value=0.02). Conclusion: We found high levels of FBI contamination in corn and rice samples from Golestan province of Iran, with a significant positive relationship between FB1 contamination in rice and the risk of EC. Therefore, fumonisin contamination in commonly used staple foods, especially rice, may be considered as a potential risk factor for EC in this high risk region

    Worldwide prevalence of emerging parasite Blastocystis in immunocompromised patients: A systematic review and meta-analysis

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    BACKGROUND: Blastocystis is one of the most common pathogens of the human intestine, caused by an emerging parasite, which can lead to severe symptoms and even death in immunocompromised patients. We aimed to determine the global prevalence of Blastocystosis infection in people with immunodeficiency. A systematic literature search was conducted on Web of Science, Scopus, Google scholar, Science Direct and MEDLINE databases to select all observational studies reporting the prevalence of Blastocystosis infection in Worldwide, based on different diagnostic methods in immunocompromised patients of any age and published from inception to February 2019. Pooled estimates and 95 confidence intervals (95 CIs) were calculated using random effects models and in addition, the I(2) statistic was calculated. The geographic distribution of studies was evaluated and the diagnosis of Blastocystis was compared by various techniques. Electronic databases were reviewed for Blastocystosis infection in HIV/AIDS, cancer and other immunocompromised patients, and meta-analyses were conducted to calculate the overall estimated prevalence. Total68 eligible studies were included. The estimated pooled prevalence rate of Blastocystosis infection in immunocompromised patients was overall 10 (95 CI, 7-13; I(2) 96.04) (P < 0.001), of whom 21 18-25 were in Australia, 12% 4-24 in America, 11% 6-17 in Europe and 10% 5-15, 7% 3-13 in Asia and Africa, respectively. It was calculated that the estimated pooled prevalence rate of Blastocystosis infection in immunocompromised patients was overall 10% and the prevalence estimates ranged from 0.44 to 72.39. Also, overall the prevalence of parasites co-infection in immunocompromised patients was detected as 0.024%. Our finding showed that immunocompromised people show a high prevalence of Blastocystosis infection compared to the control population. Adequate information on the prevalence rate is still missing from many countries. However, current information underscore that Blastocystis should not be neglected
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