A new record for Iran of Dolichogenidea appellator (Hym.: Braconidae: Microgastrinae), a larval endoparasitoid of diamondback moth, Plutella xylostella (Lep.: Plutellidae)

Observational notes and photographs taken in the course of rearing Euceros albitarsus Curtis and E. pruinosus (Gravenhorst) in captivity from the egg stage are given. The bizarre biology of these obligate hyperparasitoids involves a planidial larval stage that attaches to caterpillars or sawfly larvae, followed by a short phase of internal parasitism of a primary parasitoid if already or subsequently present, followed in turn by the principle growth period of external parasitism on the primary parasitoid, as shown by Tripp (1961). Observations on aspects of this that were not illustrated by Tripp are given and, although these transitions are not fully elucidated here, it is speculated that the number of larval instars had hitherto been overestimated. Investigations on the behaviour and fate of the planidial phase suggest that it is best able to transfer to primary parasitoids that are associated with the prepupal state of the lepidopteran host. Planidia on caterpillars that are not themselves parasitised end up in the host pupa, usually occupying the subalar cavity of the exuvial space (that is, just below the pupal cuticle at the wing cases), but do not develop further in the absence of a primary parasitoid. A summary of some aspects of the biology of Euceros that are not yet understood is given: the main uncertainties are the number and feeding positions of larval instars, the timing and nature of the planidium’s transfer to the primary parasitoid, and the func-­ tion of the unusual male antenn

Studies on the stability of population equilibrium of the diamondback moth (Plutella xylostella (Lep.: Plutellidae)) using perturbation method

Nowadays, a basic understanding of population biology is necessary to establish ecological strategies of pest management. In the present study, the population behavior of the diamondback moth after a perturbation was examined. For this purpose, a long-term experiment with three treatments (control, a perturbation using density reduction and a perturbation using density increase) was performed. The experiment was started with 10 pairs of adult moths in ventilated cages under the standard constant environment. The experiment was continued for 10 generations. After five generations, the perturbation was applied and each treatment was replicated 10 times. Adults and larvae were fed with honey solution (20%) and Chinese cabbage, respectively. The population trend and stability were monitored by weekly census counts of live adults, and the data used as a measure of abundance for the population dynamics. The results showed that the populations of the diamondback moth persisted at equilibrial levels when there was no perturbation. On the contrary, when the populations were perturbed using density reduction, the population equilibrium was shifted to a lower level; in this situation perturbations using sustainable strategies, such as the release of natural enemies or the application of microbial insecticides, may set the equilibrium beneath economic injury threshold. While, a perturbation using density increase can cause instability of population equilibrium toward a decreasing trend that may drive the population to extinction. The causes and effects of the findings in relation with the moth life history, resource competition and its ecological consequences on the population behavior were discussed

A new record for Iran of Dolichogenidea appellator (Hym.: Braconidae: Microgastrinae), a larval endoparasitoid of diamondback moth, Plutella xylostella (Lep.: Plutellidae)

طی مطالعاتی که در سال 1390 روی بید کلم، Plutella xylostella (L.)، در استان اصفهان انجام شد، یک گونه زنبور پارازیتوئید به نام Dolichogenidea appellator (Telenga) از پرورش لاروهای بید کلم جمع‌آوری‌شده از مزارع کلم‌پیچ، واقع در مرکز تحقیقات کشاورزی و منابع طبیعی استان اصفهان به‌دست آمد که برای فون ایران جدید است. این زنبور، علاوه‌بر بید کلم، بال‌پولک‌داران دیگری از خانواده Gelechiidae، نظیر Scrobipalpa salinella (Zeller) و Phthorimaea operculella (Zeller)، را نیز پارازیته می‌کند

Nanotechnology and global energy demand: challenges and prospects for a paradigm shift in the oil and gas industry.

The exploitation of new hydrocarbon discoveries in meeting the present global energy demand is a function of the availability and application of new technologies. The relevance of new technologies is borne out of the complex subsurface architecture and conditions of offshore petroleum plays. Conventional techniques, from drilling to production, for exploiting these discoveries may require adaption for such subsurface conditions as they fail under conditions of high pressure and high temperature. The oil and gas industry over the past decades has witnessed increased research into the use of nanotechnology with great promise for drilling operations, enhanced oil recovery, reservoir characterization, production, etc. The prospect for a paradigm shift towards the application of nanotechnology in the oil and gas industry is constrained by evolving challenges with its progression. This paper gave a review of developments from nano-research in the oil and gas industry, challenges and recommendations

Large-scale unit commitment under uncertainty: an updated literature survey

The Unit Commitment problem in energy management aims at finding the optimal production schedule of a set of generation units, while meeting various system-wide constraints. It has always been a large-scale, non-convex, difficult problem, especially in view of the fact that, due to operational requirements, it has to be solved in an unreasonably small time for its size. Recently, growing renewable energy shares have strongly increased the level of uncertainty in the system, making the (ideal) Unit Commitment model a large-scale, non-convex and uncertain (stochastic, robust, chance-constrained) program. We provide a survey of the literature on methods for the Uncertain Unit Commitment problem, in all its variants. We start with a review of the main contributions on solution methods for the deterministic versions of the problem, focussing on those based on mathematical programming techniques that are more relevant for the uncertain versions of the problem. We then present and categorize the approaches to the latter, while providing entry points to the relevant literature on optimization under uncertainty. This is an updated version of the paper "Large-scale Unit Commitment under uncertainty: a literature survey" that appeared in 4OR 13(2), 115--171 (2015); this version has over 170 more citations, most of which appeared in the last three years, proving how fast the literature on uncertain Unit Commitment evolves, and therefore the interest in this subject

The effect of contact angles and capillary dimensions on the burst frequency of super hydrophilic and hydrophilic centrifugal microfluidic platforms, a CFD study.

This paper employs the volume of fluid (VOF) method to numerically investigate the effect of the width, height, and contact angles on burst frequencies of super hydrophilic and hydrophilic capillary valves in centrifugal microfluidic systems. Existing experimental results in the literature have been used to validate the implementation of the numerical method. The performance of capillary valves in the rectangular and the circular microfluidic structures on super hydrophilic centrifugal microfluidic platforms is studied. The numerical results are also compared with the existing theoretical models and the differences are discussed. Our experimental and computed results show a minimum burst frequency occurring at square capillaries and this result is useful for designing and developing more sophisticated networks of capillary valves. It also predicts that in super hydrophilic microfluidics, the fluid leaks consistently from the capillary valve at low pressures which can disrupt the biomedical procedures in centrifugal microfluidic platforms

Chemical composition of elamit scrophularia deserti

Scrophulariadeserti is an annual and perennial herb, as well as a genus of shrubs. Flowers have bilateral or rarely radial symmetry reaching height of 10-50 cm. Leaves of plant are thick, hard, brittle with green color. S. deserti plant from the family of Scrophulariaceae is mostly grass or shrub and rarely trees. I has five-pointed flowers, corolla with lobes and the fruits usually have a capsule with multiple seeds. Aerial parts of Scrophulariadeserti were collected during November of 2014 in Dehloran region of Ilam province. After confirming the species and genius of the plant in natural resources research center of Ilam Province, the collected plant was dried in the air and powdered with mixer. Essential oil was extracted and analyzed with chromatography/mass spectrometry (GC-MS), SMPE method. Phytochemistry results showed that the most active ingredients of the plant were α-PINENE, β-Phellandrene and β-Myrcene which respectively formed 24. 69, 20. 58 and 11. 82 of the essential oils of the plant. © 2016, Sphinx Knowledge House. All rights reserved

Determinants of willingness to practice medicine in underdeveloped areas: Evidence from a survey on Iranian medical students

Purpose: Appropriate access to formally-trained health workers for people living in rural and underdeveloped areas is a continuing challenge worldwide. The purpose of this paper is to investigate the willingness of formally-trained health workers to practice in underdeveloped areas and its main determinants among medical students in the western provinces of Iran. Design/methodology/approach: A total of 753 medical students from four provinces in western Iran (Kermanshah, Ilam, Lorestan and Kurdistan) were surveyed cross-sectionally in 2017. A self-administrated questionnaire was used to collect data on sociodemographic characteristics, willingness to practice in underdeveloped areas, intrinsic (e.g. desire to help others and self-interest in medicine) and extrinsic (e.g. the high income of physicians and social prestige) motivations of the study population. Multivariable logistic regression was used to identify the main determinants of willingness to practice in underdeveloped areas among medical students after their graduation. Findings: The results indicated that 58.3 percent of students were willing to practice in underdeveloped areas. While 59 percent of the study population had a strong extrinsic motivation to study medicine, the remaining 41 percent of the study population had a strong intrinsic motivation to study medicine. The logistic regression results indicated that low parental professional and educational status, an experience of living in rural areas and having strong intrinsic motivation were associated with greater willingness to practice in underdeveloped areas. Originality/value: This is the first study to investigate the willingness to practice in underdeveloped areas and its main determinants among medical students in the west of Iran. © 2019, Emerald Publishing Limited