Application of finite element methods to the post-buckling behaviour of thin plates containing imperfections

A finite element program, applicable to the pre- and post-buckling behaviour of plates with imperfections, is developed. Suitable incremental stiffness matrices are generated for a plate element with four nodes and twenty degrees of freedom. Preliminary work, together with a prototype pro- gram, is carried out on a simple strut in order to compare various nonlinear solution techniques, both incremental and iterative. Th6 plate program is veri- fied by large deflection calculations for a square plate under lateral pressure, and by comparison with theoretical buckling loads for a perfect plate, closely agreeing with previous theoretical work. Experimental results in compression, both with and without an artificially introduced imperfection, are used to demonstrate real plate behaviour, and they enable a comparison to be made with computed results. Measure- ments of deflection are made by the Moire fringe tech- nique, as well as by dial gauges. The program is used to investigate the effect of buckling on the compressive and shear stiffness of plates with various degrees of imperfection, including the compressive stiffness of a square plate after buckling in shear

A comparative study on the functional response of Wolbachia-infected and uninfected forms of the parasitoid wasp Trichogramma brassicae

Trichogramma species (Hymenoptera: Trichogrammatidae) are haplo-diploid egg parasitoids that are frequently used as biological control agents against lepidopteran pests. These wasps display two reproductive modes, including arrhenotoky (bisexuality) and thelytoky (unisexuality). Thelytokous forms are often associated with the presence of endosymbiotic Wolbachia bacteria. The use of thelytokous wasps has long been considered as a way to enhance the efficacy of biological control. The present study investigates the potential of a thelytokous Wolbachiainfected and an arrhenotokous uninfected Trichogramma brassicae Bezdenko strain as inundative biocontrol agents by evaluating their functional response towards different egg densities of the factitious host, the Angoumois grain moth, Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae). The results revealed a type II functional response for both strains in which parasitism efficiency decreases with host egg density because of an increasing host handling time. A model with an indicator variable was used to compare the parameters of Holling’s disc equation in different data sets. It was demonstrated that the two strains did not differ in host attack rate. However, the Wolbachia-infected strain did have an increased host handling time when compared to the bisexual strain. Some applied aspects of the findings are discusse

Frequency of cataract in Iran: A meta-analysis and systematic review

PURPOSE: Cataract is the leading cause of blindness and the second cause of low vision in the world. In the world, Asia has the highest number of blind population. The aim of the present systematic review and meta-analysis was to assess the frequency of clinical cataracts in Iran. MATERIALS AND METHODS: The frequency of clinical cataract was defined based on the international criteria and the measured outcome of the disease. Study selection, data extraction, and quality assessment were performed by two independent reviewers. We explored PubMed, Google Scholar, ISI Web of Science, and national databases (scientific information database, Magiran) to evaluate the clinical cataract of cataract in the Iranian populations from 1995 to July 2017. Statistical analysis was performed using STATA 14.0 software. RESULTS: Of 283 studies, 27 studies utilized meta-analysis. In 2017, the pooled overall frequency of clinical cataract in 59668 people was 9.27 (95 confidence interval CI: 8.09, 10.45, I2 = 98.82%). Based on subgroup analysis, in the random effect method, the frequency of clinical cataract in males and females were 8.03% (CI: 6.78, 9.28) and 8.32% (CI: 7.08, 9.55), respectively. CONCLUSION: Regarding the high frequency of clinical cataract in Iran, it seems that paying attention to the results of the current study and the application of international policy plans may contribute to better cataract control in Iran. © 2018 Middle East African Journal of Ophthalmology

Effective factors on adoption technology among trout fish farms in Guilan Province

The main purpose of this study was to investigate effective factors on adopting technologies among trout fish farmers in Guilan province by Unified Theory of Acceptance and Use of Technology (UTAUT). Statistical population of this research contained of all managers of trout fish farms of Guilan province (N=170) that base on limitation of structural equation modelling in determining sample size, 97 of them were chosen as a sample. Study tool was contained Vankatesh and et al. information technology questionnaire in six items. To obtain validity of questionnaire; content, face, convergent and discriminant validity were used. As well, to obtain reliability of questionnaire; principal component analysis, Cronbachs alpha, Dillon-Goldstein’s ʃ and reagent stability were used. To accomplish analysis of data, SPSSV19 and SmartPLSV2 software were used in descriptive and inferential statistics. For testing hypothesis, structural equation model (SEM) and partial least squares (PLS) that focus on reagent variance were used. The results showed that there was significant relationship between performance expectancy and behavioral intention. Also there was significant relationship between intention to use and use behavior of aquaculture technologies. Model explains 28.8 percent of behavioral intention variance and 7.9 percent of use behavior of aquaculture technologies variance among trout fish farmers. To increase willingness to accept the technology among trout fish farms in Guilan province, it is suggested that extension-education courses for raising knowledge and awareness of aquaculture technology to be held by organizations. Providing financial resources and adequate knowledge will enable trout fish farms to equip with the aquaculture technologies

First record of Goniozus legneri (Hym.: Bethylidae), the larval ectoparasitoid of carob moth, in Iran

A larval parasitoid of carob moth, Ectomyelois ceratoniae (Zeller), was collected in pomegranate orchards in Fars province, Iran, during 2009-2010. This parasitoid, which is newly recorded from Iran, was identified as Goniozus legneri Gordh (Hym.: Bethylidae) by J. de Rond (Lelystad, The Netherlands)

Natural parasitism of Telenomus busseolae (Hym.: Scelionidae) an egg parasitoid of sugarcane stem borers, Sesamia spp. (Lep.: Noctuidae), on sugarcane commercial varieties in Khuzestan

The sugarcane stem borers, Sesamia cretica Led. and S. nonagrioides Lef. are the most important pests of sugarcane in Iran. The egg parasitoid wasp, Telenomus busseolae Gahan is the most important natural enemy of Sesamia spp. in Khuzestan province that play an important role in regulating populations of sugarcane stem borers. A field experiment was conducted to evaluate the performance of T. busseolae on sugarcane commercial varieties in Khuzestan province (southwest of Iran). This study was conducted in a split plot design on 4 sugarcane commercial varieties (i.e. CP69-1062, CP48-103, CP57-614 and SP70-1143) with 5 fields per variety in Khuzestan in 2007. The sampling of egg masses were carried out within the tillering stage of sugarcane (5-15 June) and the final stage of sugarcane growing (10-20 October). Our results indicated that both growth stage and variety of sugarcane had a significant effect on the egg batch density, discovery efficiency and percent parasitism. The interaction between growth stage and variety on percent parasitism and discovery efficiency were statistically different (

A double-blind, randomized comparison study between Zytux� vs MabThera® in treatment of CLL with FCR regimen: Non-inferiority clinical trial

Background: Chronic lymphocytic leukemia (CLL) is characterized by accumulation of B cells in blood, lymphoid tissues and bone marrow. Addition of rituximab to CLL chemotherapy regimens has been associated with improved survival. The aim of this study was to establish efficacy and safety of Zytux� in comparison to MabThera® in treatment of CLL. Materials and Methods: Seventy CLL patients who met the criteria for entering the study were randomized into two groups (35 patients in each group). Both groups received Fludarabine and Cyclophosphamide plus Rituximab as part of the FCR regimen. Group A was treated with Zytux�, and group B was treated with MabThera®. A non-inferiority margin of 20 for the primary outcome was defined to examine the similarity between Zytux� and MabThera®. Results: Baseline demographic characteristics showed no statistically significant difference between the two groups. The two treatment groups were comparable in terms of laboratory and clinical findings, cellular index changes and CD (5, 19, 20 and 23) counts during therapy cycles and at the end of the treatment period. Regarding safety results, Zytux� demonstrated a similar profile of adverse reactions in comparison to MabThera®. Moreover, the overall response rate was 88 and 89 for Zytux� and MabThera®, respectively (CI -0.17, 0.18). Conclusion: Results showed non-inferiority of Zytux� in terms of efficacy and adverse events as a biosimilar version of MabThera®. © 2018, Tehran University of Medical Sciences (TUMS). All rights reserved

Report of a thelytokous population of Lysiphlebus fabarum (Hym.: Aphidiidae) from Iran

به منظور جمع‌آوری و شناسایی پارازیتوئیدهای شته‌ی سیاه باقلا، Scopoli Aphis fabae، از مزارع باقلای منطقه‌ی چورزق زنجان در اواسط خرداد‌ماه 1386 نمونه‌برداری به عمل آمد. در بین نمونه‌ها، جمعیت ماده‌‌زای زنبور پارازیتوئید Lysiphlebus fabarum (Marshall) از خانواده‌ی Aphidiidae شناسایی شد که برای اولین‌بار از ایران گزارش می‌‌شود. در زیر برخی ازویژگی‌‌های مهم تولید مثلی و چگونگی پراکنش جغرافیایی این جمعیت ارایه شده است