Isomerization of beta-HCH in aqueous solution

beta-HCH was shaken with distilled water at 25 +/- 1 degree C for different time intervals and filtered. The ether extract of the filtrate on analysis by gas liquid chromatography showed the presence of four isomers, alpha, beta, gamma and delta, besides other compounds, thereby indicating isomerization of the beta-isomer in aqueous solution. Further, the ether extract, when dried and dissolved in acetone, showed high toxicity to mosquito larvae, flour beetle larvae and house-flies thereby indicating conversion of the inert beta-isomer to more toxic forms corroborating GLC analysis. Acetone solution of pure beta-HCH was found nontoxic against the insects tested.     

An immunological axis of biocontrol: infections in field-trapped insects

Insect immunology is an active research arena, however, the vast majority of research in the area is conducted on model species taken from laboratory cultures. We tested the hypothesis that insects are regularly exposed to infections or invasions in nature and here report results of a field study designed to assess the extent of natural infections in insects collected from agrarian fields surrounding Kahramanmaraş, Turkey. Specimens were dissected to assess numbers of nodules. Formation of darkened, melanotic nodules is the predominant cellular immune reaction to microbial and parasitic infection, and once formed, the nodules are permanently attached to internal surfaces. The collected insects were healthy. Of the >400 examined specimens, at least some nodules were found in 98%. Numbers of nodules ranged from ∼2/individual to >100 nodules/individual. We conclude that insects are regularly challenged by microbial and parasitic infections from which they recover. The novel implication of our data is that insect immune systems may limit the host range and effectiveness of agents deployed in biological control programs. Knowledge of insect immune systems may contribute to increased use of biopesticides globally.     

Inbreeding and the evolution of sociality in arthropods

Animals have evolved strategies to optimally balance costs and benefits of inbreeding. In social species, these adaptations can have a considerable impact on the structure, the organization, and the functioning of groups. Here, we consider how selection for inbreeding avoidance fashions the social behavior of arthropods, a phylum exhibiting an unparalleled richness of social lifestyles. We first examine life histories and parental investment patterns determining whether individuals should actively avoid or prefer inbreeding. Next, we illustrate the diversity of inbreeding avoidance mechanisms in arthropods, from the dispersal of individuals to the rejection of kin during mate choice and the production of unisexual broods by females. Then, we address the particular case of haplodiploid insects. Finally, we discuss how inbreeding may drive and shape the evolution of arthropods societies along two theoretical pathways.     

An equal sex ratio followed by differential sex mortality causes overestimation of females in gall midges: no evidence for sex ratio regulation

Monogeny, the production of unisexual broods by individual females, has been recognized for nearly 80?years. The genetic nature of gall midges' sex determination predicts an equal numbers of male-producing and female-producing females in the populations such that the overall sex ratio is expected to be nearly 1:1. However, observations of some strictly monogenous populations with biased sex ratio, mainly toward females, have raised the question of whether gall midges are able to adjust their offspring sex ratio in response to changes in environmental conditions, and some authors have even considered sex ratio regulation as a strong force in the course of the evolution of monogeny. In this paper, first, by studying the sex ratio variations of the predatory gall midge, Aphidoletes aphidimyza within a generation, we showed that adult males emerge up to 1?day earlier and have shorter life span than females (less than 4?days and up to 6?days, respectively). Although, the sex ratio of A. aphidimyza at the time of emergence was nearly 1:1 (52.41?% males), a simple population simulation indicated that the differential mortality of sexes can lead to a female-biased sex ratio estimation (57.88?% females) under random sampling in the natural environments. Our results imply that the primary sex ratio of monogenous gall midges is nearly 1:1 and that the arrhenogenic/thelygenic gall midges are not able to alter the number of their male/female progenies in response to changes in environmental conditions.     

Stand-alone PV-hydrogen energy system in Taleghan-Iran using HOMER software: optimization and techno-economic analysis

One of the most attractive features of hydrogen as an energy carrier is that it can be produced from water. Hydrogen has the highest energy content per unit mass as compared to chemical fuel and can be substituted. Its burning process is non-polluting, and it can be used in the fuel cells to produce both electricity and useful heat. Photovoltaic arrays can be used in supplying the water electrolysis systems by their energy requirements. During the daylight hours, the sunlight on the photovoltaic array converts into electrical energy which can be used for electrolyzer. The hydrogen produced by the electrolyzer is compressed and stored in hydrogen vessel and provides energy for the fuel cell to meet the load when the solar energy is insufficient. This study investigates a stand-alone power system that consists of PV array as power supply and electrolyzer. They have been integrated and worked at the Taleghan renewable energies’ site in Iran. The National Renewable Energy Laboratory’s Hybrid Optimization Model for Electric Renewables simulation software has been used to carry out the optimal design and techno-economic viability of the energy system. The simulation results demonstrate that energy system is composed of 10-kW PV array, 3.5-kW electrolyzer, 0.4-kW proton exchange membrane fuel cell, 2.5-kW inverter, and 60 batteries (100 Ah and 12 V). The total initial capital cost, net present cost, and cost of electricity produced from this energy system are 193,563 US$, 237,509 US$, and 3.35 US$/kWh, respectively.     

Evaluation of ecological risk,source, and spatial distribution of some heavy metals in marine sediments in the Middle and Eastern Black Sea region,Turkey

Environmental Science and Pollution Research - In the present study, the concentration levels of heavy metals such as Mn, Fe, Ni, Cu, Zn, Cr, and Pb in sediment samples collected from 16 sampling...     

Optimization of metal bio-acid leaching from mobile phone printed circuit boards using natural organic acids and H2O2

Journal of Material Cycles and Waste Management - With increased popularity and technological innovation, more and more electric and electronic equipment wastes (e-wastes) are being generated....     

Microfibrillated Cellulose-Silver Nanocomposite Based PVA Hydrogels and Their Enhanced Physical,Mechanical and Antibacterial Properties

Journal of Polymers and the Environment - Modification of cellulose with silver nanoparticles produces various nanocomposites with significantly developed properties. This work aims to prepare a...     

Design and optimization of new La1−xCexNi1−yFeyO3 (x,y = 0–0.4) nano catalysts in dry reforming of methane

The paper reports the production of syngas from dry reforming of methane (DRM) over La_1?xCe_xNi_1?yFe_yO₃ (x, y = 0–0.4) perovskites. A series of La_1?xCe_xNi_1?yFe_yO₃ were designed by central composite design (CCD) and synthesized by a sol–gel auto combustion method. Artificial neural network (ANN) approach was used to determine the relationship between preparation and operational parameters on the performance of the catalysts in the DRM process. Nickel mole fraction, lanthanum mole fraction, calcination temperature, and reaction temperature were considered as input variables, and conversion of methane was considered as the output variable. An ANN model with nine neurons in the hidden layer was the suitable in predicting conversion of methane. The genetic algorithm (GA) was subsequently used to determine the optimal preparation condition for enhancing the conversion of methane. La_0.6Ce_0.4Ni_0.99Fe_0.01O₃ catalyst, calcined at 756°C was obtained to be the most active catalyst owing to the optimal composition of nickel and lanthanum in the catalyst formulation.