Cloning of the hsp70 (dnaK) genes from Rhizobium meliloti and Pseudomonas cepacia: phylogenetic analyses of mitochondrial origin based on a highly conserved protein sequence.

The genes for hsp70 (or dnaK) have been cloned and sequenced from Rhizobium meliloti and Pseudomonas cepacia, two bacterial species belonging to the alpha- and beta-subdivisions of gram-negative proteobacteria, respectively. On the basis of global alignment of HSP70 proteins, several sequence signatures have been identified that are distinctive of mitochondrial homologs and gram-negative proteobacteria on the one hand and the chloroplasts and cyanobacteria on the other. Detailed phylogenetic analyses of HSP70 sequences from various eubacteria and eukaryotic organellar and cytosolic homologs support the inference regarding the origin of mitochondria from a member of the alpha-proteobacteria and of chloroplasts from cyanobacteria. The analysis presented here also suggests a monophyletic origin of the mitochondrial homologs.     

Resource allocation mechanisms for maximizing provider’s revenue in infrastructure as a service (IaaS) cloud

Infrastructure as a Service (IaaS) is a cloud computing service provided over the internet to facilitate the provisioning of various services such as storage, processes, etc. The provider in the IaaS market may offer some purchasing plans including: reservation, on-demand, and spot plans for its resources. As in real scenarios, demand volume for each plan is assumed to be a random variable with a given probability distribution. The provider maximizes its average revenue in the long run by optimal allocation of its resources among the plans. We formulate an Integer Linear Programming (ILP) model with a stochastic constraint, to determine the number of resources to be allocated for each plan in every time slot in the planning horizon. First, fixed prices are considered for each plan, then two mechanisms of Continuous Double Auction and Second Price Sealed Bid Auction are considered for reservations and spot plans, respectively, to obtain market-driven prices of the services. The Seasonal Weighted Moving Average method is used to predict the amount of demand in every slot. Finally, the proposed mechanisms are evaluated through simulations and the results confirm the effectiveness of the methods in maximizing the revenue and overall utilization of the available IaaS capacity.

     

Optimisation of a microwave-assisted method for extracting withaferin A from Withania somnifera Dunal. using central composite design

Introduction – Recently, there have been growing attention on the modification and optimisation of new extraction and quantification methods, caused by the lack of environmentally friendly methodologies for the extraction of phytochemicals from complex matrices. In the case of pharmaceutical compounds, not only the extraction procedure but also the analysis method should be efficient, precise, fast and easy. Objectives – The essential pharmaceutical characteristics and trace concentration of withanolides led us to modify and optimise the previously reported extraction and quantification procedure for withaferin A (WA) as a candidate for withanolides. Matrial and methods – The WA from the air‐dried aerial part of Withania somnifera Dunal. was extracted using a microwave‐assisted extraction (MAE) technique. Four variables affecting the extraction procedure were optimised using the central composite design approach. The method of high‐performance thin‐layer chromatography assay was validated and applied for the quantification of each experiment. Results – The optimum values of factors were: extraction time (150 s), extraction temperature (68°C) and 17 mL of methanol : water in the ratio 25 : 75 as extracting solvent. The solvent system consisted of ethyl acetate : toluene : formic acid : 2‐propanol (7.0 : 2.0 : 0.5 : 0.5, v/v/v/v), and densitometric scanning at 220 nm was applied for the analysis. The dynamic linear range, LOD, LOQ and recovery with the inter‐day, and intra‐day RSDs of the developed method indicated the validity of the method. Conclusion – A pressurised MAE method for extracting WA from the plant's aerial part was optimised using factorial‐based design. The net effect of time, temperature, solvent volume and its ratio suggests that the yield of WA increases until each factor reaches its optimum value, and decreases with further increase in temperature or solvent ratio. Copyright © 2010 John Wiley & Sons, Ltd.     

Homozygosity mapping in consanguineous families reveals extreme heterogeneity of non-syndromic autosomal recessive mental retardation and identifies 8 novel gene loci

Autosomal recessive gene defects are arguably the most important, but least studied genetic causes of severe cognitive dysfunction. Homozygosity mapping in 78 consanguineous Iranian families with nonsyndromic autosomal recessive mental retardation (NS-ARMR) has enabled us to determine the chromosomal localization of at least 8 novel gene loci for this condition. Our data suggest that in the Iranian population NS-ARMR is very heterogeneous, and they argue against the existence of frequent gene defects that account for more than a few percent of the cases. Mohammad Mahdi Motazacker and Masoud Garshasbi have contributed equally to this work.     

Preliminary findings of age and male sexual characteristics andand potential effect to semen characteristics and cryopreservation of the critically endangered Bornean orangutan in Malaysia

Primates - Bornean orangutan is a critically endangered non-human primate; however, the threat of extinction is not merely from poaching and habitat loss. Orangutan survival is also threatened by...     

Fabrication of a novel nanocomposite based on sol-gel process for hollow fiber-solid phase microextraction of aflatoxins: B1 and B2, in cereals combined with high performane liquid chromatography-diode array detection

The new pre-concentration technique, hollow fiber-solid phase microextraction based on carbon nanotube reinforced sol-gel and liquid chromatography-photodiode array detection was applied to determination of aflatoxins B(1), B(2) (AFB(1), AFB(2)) in rice, peanut and wheat samples. This research provides an overview of trends related to synthesis of solid phase microextraction (SPME) sorbnents that improves the assay of aflatoxins as the semi-polar compounds in several real samples. It mainly includes summary and a list of the results for a simple carbon nanotube reinforced sol-gel in-fiber device. This device was used for extraction, pre-concentration and determination of aflatoxins B1, B2 in real samples. In this technique carbon nanotube reinforced sol was prepared by the sol-gel method via the reaction of phenyl trimethoxysilane (PTMS) with a basic catalyst (tris hydroxymethyl aminomethan). The influences of microextraction parameters such as pH, ageing time, carbon nanotube contents, desorption conditions, desorption solvent and agitation speed were investigated. Optimal HPLC conditions were: C(18) reversed phase column for separation, water-acetonitril-methanol (35:10:55) as the mobile phase and maximum wavelength for detection was 370 nm. The method was evaluated statistically and under optimized conditions, the detection limits for the analytes were 0.074 and 0.061 ng/mL for B1 and B2 respectively. Limit of quantification for B1 and B2 was 0.1 ng/mL too (n=7). The precisions were in the range of 2.829-2.976% (n=3), and linear ranges were within 0.1 and 400 ng/mL. The method was successfully applied to the analysis of cereals (peanut, wheat, rice) with the relative recoveries from 47.43% to 106.83%.     

Citric acid improves growth performance and phosphorus digestibility in Beluga (Huso huso) fed diets where soybean meal partly replaced fish meal

A 2 × 3 factorial experiment was conducted to evaluate the effect of partial substitution of dietary fish meal with soybean meal and citric acid (CA) supplementation on growth, food utilization, muscle composition and nutrient digestibility of Beluga, Huso huso. Three isonitrogenic and isoenergetic diets, as SBM₁ (soybean meal protein (SBP):fishmeal protein (FP) = 1:3), SBM₂ (SBP:FP = 2:3) and SBM₃ (SBP:FP = 1:1) containing two levels of CA (0 and 30 g kg⁻¹) were fed to triplicate groups of fish for 8 weeks. The results revealed that adding CA increased (P<0.05) the weight gain (WG), specific growth rate (SGR) and protein efficiency ratio (PER) and decreased (P<0.05) food conversion rate (FCR) whereas partial substitution of fishmeal with soybean meal decreased (P<0.05) growth performance. Partial replacement of fishmeal with SBM (P=0.021) as well as CA supplementation (P=0.019) and their interaction (P<0.001) affected hepatosomatic index (HSI). No differences (P>0.05) were observed for viscerosomatic index (VSI) among treatments (P>0.05). No differences (P>0.05) were detected in moisture, protein of muscle sample among treatments, but lipid content was reduced (P<0.05) while ash content increased (P=0.035) by CA. Soybean meal decreased (P<0.05) nutrient digestibility, whereas CA improved apparent protein and phosphorus (P) digestibility (P=0.011 and P<0.001 respectively). No interaction (P<0.05) between levels of SBM and CA was found on these parameters. Results of the present study indicate that Beluga has a limited ability to utilize SBM as a protein source in practical diets whereas CA can improve growth and nutrient utilization in Beluga.     

The effects of BmNPV on biochemical changes in primary cultures of Bombyx mori embryonic tissue

The effect of Bombyx mori nuclear polyhedrosis virus (BmNPV) on biochemical changes of TC-100 medium containing 10% fetal bovine serum (FBS) in embryonic primary cultures of silkworm was investigated. The primary cultures that reached 60% confluence were infected by 0.5, 1, and 2-ml viral inoculums (diluted with TC-100 medium representing multiplicity of infection (MOI) of 0.25, 0.5, and 1). Glucose, uric acid, urea, total protein, cholesterol, and alkaline phosphatase were measured in the medium of BmNPV-infected primary cultures. All biochemical compounds showed significant changes. Glucose decreased considerably by about 55 mg/ml, while different concentrations of the virus inoculums did not demonstrate significant differences among them. Total protein had only increased in 2 ml concentration and there were no changes in other concentrations. Uric acid as a by-product accumulated dramatically in all concentrations, while the amount of urea reduced in all treatments and this reduction was more evident in lower concentrations. Cholesterol consumption was high in cultures postinfection, while alkaline phosphatase (ALP) activity decreased in infected cells.     

Castration induced changes in dog prostate gland associated with diminished activin and activin receptor expression

This study was conducted to evaluate the effect of androgen ablation on dog prostate gland structure and the proliferation capacity of the prostatic cells and their association with the expression of Activin A and Activin RIIA receptor. The effect of androgen on the prostate gland was compared in intact and castrated dogs after one and two weeks. Specific primary antibodies were used to immunolocalize activin-A, activin receptor type II A and the proliferation marker (PCNA). The results showed that the glandular acini of the prostate gland of intact dogs are lined by tall columnar secretory cells and less abundant flattened basal cells and surrounded by a thin fibromuscular tissue. The cytoplasm of the glandular cells exhibited an intense immunoreaction for activin A and activin RIIA receptor while basal cells expressed PCNA. Castration induced a remarkable atrophy of the prostatic acini associated with a progressive loss of secretory epithelial cells, which showed a dramatic decrease to complete disappearance of Activin A and Activin RIIA receptor immunoreactions. The remaining cells of the atrophied acini continue to express PCNA and the inter-acinar fibromuscular tissue showed a remarkable increase in its mass and are induced to express PCNA. These results indicated that androgen is required for the survival of epithelial cells and to maintain growth-quiescent fibromuscular cells, while basal cell proliferation is androgen independent. The changes in the Activin A and Activin RIIA receptor localization and their association with the dynamic pattern of prostate gland regression after castration suggested that Activin A and Activin RIIA receptor expression are androgen dependent.