Phytochemical Characterization of Phagnalon graecum Boiss. by HPLC and GC-MS with its Enzyme Inhibitory and Antioxidant Activity Profiling by Spectrophotometric Methods

In the current study, the n-hexane, chloroform, ethyl acetate, methanol, and water extracts of Phagnalon graecum Boiss. (Asteraceae), a spice plant, were investigated for their enzyme inhibitory activity against acetylcholinesterase, butyrylcholinesterase, lipoxygenase, tyrosinase, and antioxidant activities. Antioxidant activity of the extracts was determined by 2,2-diphenyl-1-picrylhydrazyl radical scavenging, ferric ion-chelation activity, and ferric-reducing antioxidant power tests. Total phenol (gallic acid equivalent) and flavonoid (quercetin equivalent) contents were calculated. Essential oil of the plant was analyzed by GC-MS, while the selected phenolic acids were analyzed by HPLC. The extracts had insignificant inhibition against the tested enzymes, whereas they displayed a remarkable antioxidant activity. Therefore, to the best of our knowledge, this study presents the first data on biological activity and phytochemical content of P. graecum and this species could be utilized as potential antioxidant applicable for food preservation.     

Intensity modulated short circuit current spectroscopy for solar cells

Understanding charge separation and transport is momentously important for the rectification of solar cell performance. To probe photo-generated carrier dynamics, we implemented intensity modulated short circuit current spectroscopy (IMSCCS) on porous Si and Cu(In_x,Ga_1−x)Se₂ solar cells. In this experiment, the solar cells were lightened with sinusoidally modulated monochromatic light. The photocurrent response of the solar cell as a function of modulation frequency is measured as the optoelectronic transfer function of the system. The optoelectronic transfer function introduces the connection between the modulated light intensity and measured AC current of the solar cell. In this study, interaction of free carriers with the density of states of the porous Si and Cu(In_x, Ga_1−x)Se₂ solar cells was studied on the basis of charge transport time by IMSCCS data.     

Stress distributions in energy generating two-layer tubes subjected to free and radially constrained boundary conditions

Analytical solutions are obtained for thermally induced axisymmetric elastic and elastic–plastic deformations in heat generating composite tubes having a free inner and a radially constrained outer boundaries. Tresca's yield condition and its associated flow rule are used to determine the elastic–plastic response of the assembly. Depending on the physical properties of the materials used, eight different plastic regions with different mathematical forms of the yield condition may occur in the assembly. The closed form solutions for these plastic regions are obtained by assuming linearly hardening material behavior. Various numerical examples are handled using thermal and mechanical properties of real engineering materials.     

Multiple professional identities: Examining differences in identification across work-related targets.

Although there is a growing literature on organizational identification, relatively little research has investigated other possible targets of identification. In a sample of veterinarians working in a wide range of organizations, the authors compared their identification with the veterinary profession, their organization, and their workgroup. The authors found different patterns of identification across these targets depending on whether the individual (a) worked in a veterinary medicine or nonveterinary medicine organization and (b) was an owner/partner or an associate. Owners of veterinary medicine organizations identified more with the organization than with either the profession or their workgroup. Associates in veterinary medicine organizations identified more with the organization and the workgroup than with the profession. Veterinarians in nonveterinary medicine organizations identified more with the profession and their workgroup than with the organization. Identification with each of the targets provided independent predictive validity of job satisfaction. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The Behaviour of Pyrethroids Indoors: A Model Study

Abstract Pest control agents containing three different formulations of the pyrethroids permethrin and deltamethrin and/or pyrethrines and the synergist piperonyl butoxide were applied in a model house simulating indoor pest control. The concentrations of the agents were monitored in the gas phase, on suspended particles, house dust and on furniture surfaces over a period of 24 months. Permethrin and deltamethrin were detected only in the gas phase immediately after application of the agents. High concentrations of deltamethrin (?2 μg/m³) and permethrin (?40 μg/m³) were found on suspended particles directly after application. This concentration decreased rapidly within two days (deltamethrin ?5 ng/m³, permethrin ?100 ng/m³) but much more slowly during the following 24 months. In house dust, deltamethrin was observed with initial concentrations of ?50 mg/kg and permethrin at initial concentrations of 150–800 mg/ kg (depending on the formulation). The concentration levels of both compounds decreased by a factor of ?10 within the first 12 months but remained almost constant thereafter. Decontamination of the rooms using a commercially available household cleanser has little effect on the pyrethroid concentration found on suspended particles, but leads to a substantial reduction of the contamination level in house dust and on furniture surfaces.     

Health issues at work: Opportunities for industrial/organizational psychology.

The workplace provides an excellent setting for addressing issues of health, and industrial/organizational psychologists have a great deal to contribute to this effort. Five models for addressing health at work are presented along with the recommendation to use the broader systems approach. A set of criteria for health research and practice is introduced, and the potential contributions of industrial-organizational psychology for addressing these criteria are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Speciation of arsenite and arsenate in rice grain – Verification of nitric acid based extraction method and mass sample survey

Arsenite and arsenate speciation was performed in 121 commercially purchased samples of 12 rice types to understand their relative relevance in rice grain. General effectiveness of a recently developed extraction protocol based on 0.28 M nitric acid at 95 °C was verified by checking the recovery of total grain arsenic and by comparing arsenic speciation in NIST-CRM-1568a, NMIJ-CRM-7503a and IMEP-107 with certificated and literature values. The arsenic speciation highlights the predominance of arsenite in 115 and dimethylarsinic acid in six samples and common minor components including arsenate, monomethylarsonic acid and two unknown arsenical species. Our data also indicate potential influences of other trace elements on As speciation in rice grain. Averagely, arsenite accounts for 90% of inorganic grain arsenic regardless of geographic origin, rice type, grain size, cultural practice and polish treatment. The high arsenite predominance indicates an elevated toxic effect of arsenic in rice than is perceived to date.     

A hybrid genetic algorithm for mixed model assembly line balancing problem with parallel workstations and zoning constraints

In this paper, we propose a hybrid genetic algorithm to solve mixed model assembly line balancing problem of type I (MMALBP-I). There are three objectives to be achieved: to minimize the number of workstations, maximize the workload smoothness between workstations, and maximize the workload smoothness within workstations. The proposed approach is able to address some particular features of the problem such as parallel workstations and zoning constraints. The genetic algorithm may lack the capability of exploring the solution space effectively. We aim to improve its exploring capability by sequentially hybridizing the three well known heuristics, Kilbridge & Wester Heuristic, Phase-I of Moodie & Young Method, and Ranked Positional Weight Technique, with genetic algorithm. The proposed hybrid genetic algorithm is tested on 20 representatives MMALBP-I and the results are compared with those of other algorithms.