The impact of local policies on the quality of packet routing in paths,trees, and rings

We consider the packet routing problem in store-and-forward networks whose topologies are either paths, trees, or rings. We are interested by the quality of the solution produced, with respect to a global optimal solution, if each link uses a (fixed) local policy to schedule the packets which go through it. The quality of the derived solutions is measured using the worst case analysis for two global optimality criteria, namely the maximum arrival date of a packet at its destination (or makespan) and the average arrival date of the packets at their destinations. We consider the setting where n packets, each one having a size (or length) and a destination, are released from the same source. In the case of rings, there exist two paths between the source and a destination. Each packet is owned by a user which chooses a path to its destination. We assume that users are rational: knowing the local policy used by the links and the state of the network, a user chooses the path which minimizes the arrival date of its packet at its destination. We are then interested by the quality of the Nash equilibria obtained.     

The rebodying of stirred yoghurt: interactions between proteins

The aim of the present study was to identify the nature of bonds established between protein particles after stirring that are responsible for the texture improvement of stirred yoghurts, called rebodying. Using a constant model yoghurt at pH 4.4, the effects of changes in the physicochemical conditions at stirring were studied on the subsequent rebodying. Short term rebodying was measured as the changes in viscoelastic properties at 4 degrees C during 20 h after stirring, while long-term rebodying was measured as the viscosity changes during 28 d storage at 4 degrees C. Moreover, stirred gels obtained from either set gels that were allowed time or not for ionic equilibration were compared. Increasing or decreasing ionic strength did not change the properties of stirred gels. Calcium chloride addition significantly decreased G'0 h, G'20 h and tan20 h but did not induce changes in the gel microstructure as observed by confocal scanning microscopy. Yoghurt rebodying could not be explained by fulfilling ionic equilibrium. Moreover, N-ethyl maleimide addition had no effect on the stirred yoghurt. Attractive electrostatic and disulphide interactions were not involved in the gel rebodying and increasing calcium concentration in the set gel limited rebodying.     

A comprehensive survey of the laminins and collagens type IV expressed in mouse Leydig cells and their regulation by LH/hCG

Extracellular matrix (ECM) proteins have been shown to alter Leydig cell steroidogenesis in vitro, substantiating the hypothesis that Leydig cell steroidogenic activity and matrix environment are interdependent events. However, the nature of the ECM components synthesized by Leydig cells and their regulation by LH/human chorionic gonadotropin (hCG) remain unknown. Here, we examine the occurrence of the 11 laminin subunits and the 6 alpha chains of collagen IV (COL4A1-6) by RT-PCR in Leydig cells cultured with or without LH/hCG. Leydig cells were a tumor Leydig cell line (mLTC-1) or 8-week-old mice Leydig cells. Based on PCR data, it is suggested that normal Leydig cells may synthesize a maximum of 11 laminin heterotrimers and the 6 alpha chains of collagen IV. They also may synthesize various proteases and inhibitors of the metzincin family. The mLTC-1 cells have a limited repertoire as compared with normal Leydig cells. Interestingly, none of the ten proteases and inhibitors monitored is under LH-hCG regulation whereas every protease and inhibitor of the serine protease family yet identified in Leydig cells is under gonadotropin regulation. In addition, a few laminin and collagen subunit genes are regulated by LH/hCG. These are laminins alpha3 and gamma3 (Lama3 and Lamc3), Col4a3, and Col4a6, which are negatively regulated by LH/hCG in both Leydig cell types, and Col4a4, which was downregulated in primary cultures but not in mLTC-1 cells. Collectively, the present study suggests that Leydig cells modulate in a selective fashion their matrix environment in response to their trophic hormone. This may alter the steroidogenic outcome of Leydig cells.     

A critical analysis of cross-cultural research and testing practices: Implications for improved education and training in psychology.

Psychological research that involves cross-cultural comparisons has increased considerably during the last decade and is expected to escalate further. Given its growing popularity within mainstream psychology, cross-cultural research no longer can be considered the sole domain of experts trained in this specialization. Concomitant with this expansion, important methodological advances in quantitative psychology (e.g., measurement, statistical analysis, and research design) impact the study of cultural differences. The purpose of this article is to heighten awareness of important methodological advances among psychologists being prepared for or engaged in teaching, research, consultation, or other forms of practice that focus on diverse cultural groups. Credible and unbiased research findings coupled with psychometrically sound selection and use of assessment instruments contribute importantly to attaining the gold standard for all psychological research and testing practices. This article highlights methodological advancements and other issues that bear importantly on both the preparation and subsequent practices of psychologists in ways that promote credibility and lessen bias. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Occurrence of Plesiomonas shigelloides in displayed portions of saltwater fish determined by a PCR assay based on the hugA gene

PCR primers were designed and used to amplify a 435-bp fragment from the Plesiomonas shigelloides hugA gene. The PCR assay combined with a non-selective enrichment step proved to be a reliable procedure for P. shigelloides detection in fish meat. The incidence of this bacterium was investigated in 52 lots of pre-packed saltwater fish portions (conger, swordfish, sole, grouper, whiting and halibut) displayed at two hypermarkets by a conventional two-step procedure and the PCR assay. Using the former, P. shigelloides was isolated from three lots of grouper fillets and one lot of halibut fillets. When PCR was performed with non-selective enriched cultures of fish portions, amplification products were obtained from samples that were positive by the culturing method and from eight additional lots of grouper fillets that gave negative results with the conventional procedure. After a secondary enrichment in tetrathionate broth without iodine, all PCR-positive non-selective enrichments yielded P. shigelloides colonies. Overall, P. shigelloides was found in 23% of the examined lots of marine fish (11 of grouper and one of halibut).     

Physicochemical properties of Venezuelan breadfruit (Artocarpus altilis) starch

Artocarpus altilis, seedless variety, is a fruit-producing plant which is cultived in Margarita Island, Venezuela, and is consumed by the inhabitants of the region. Its chemical composition and physical characteristics were determined. The chemical (AOAC and AACC methods), physicochemical, morphometric characteristics, viscoamylographic properties and digestibility in vitro of starch from Artocarpus were studied. The starch yield was 18.5 g/100 g (dw)w with a purity of 98.86%, 27.68 and 72.32% of amylose and amylopectin, respectively. Scanning electron microscopy showed irregular-rounded granules. Swelling power, water absorption and solubility values were determined and found to be higher than that of corn and amaranth starch. The amylographic study showed a gelatinization temperature at 73.3 degrees C, with high stability during heating and cooling cycles. Artocarpus starch could also be categorized in the group of mixed short chain branched/long chain branched glucan starches, this agrees with digestibility results that showed a high degree of digestibility in vitro. These results might be advantageous in medical and food use.     

Eastern values: A comparison of managers in the United States, Hong Kong, and the People's Republic of China.

Assessed the differences and similarities in values among practicing managers in the US, Hong Kong, and the People's Republic of China. The Chinese Value Survey (CVS), an instrument based on Eastern cultural values, was used instead of the typically used Western instruments. Discriminant analysis was used to identify which of 4 CVS dimensions accounted for the significant differences among the 3 S groups. The models of the discriminant analysis are discussed and compared with the hypothesized relationships among the 3 countries. The findings indicate that 3 CVS dimensions, Integration, Confucian Work Dynamism, and Human Heartedness, discriminated among the groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

主板行情

Socket AM2接口将成为AMD的新平台，这意味着芯片组的改朝换代即将到来。Socket M2接口的处理器都内置支持DDB2 667的内存控制器，因此主板将无法使用现有的DDB400内存。这两种内存的供电组模存在一定的区别，所以简单的转接卡几乎无望实现类似当年“图拉丁”的神话。     

Exploring the Active Conformation of Cyclohexane Carboxylate Positive Allosteric Modulators of the Type 4 Metabotropic Glutamate Receptor

The active conformation of a family of metabotropic glutamate receptor subtype 4 (mGlu₄) positive allosteric modulators (PAMs) with the cyclohexane 1,2‐dicarboxylic scaffold present in cis‐2‐(3,5‐dichlorophenylcarbamoyl)cyclohexanecarboxylic acid (VU0155041) was investigated by testing structurally similar six‐membered ring compounds that have a locked conformation. The norbornane and cyclohexane molecules designed as mGlu₄ conformational probes and the enantiomers of the trans diastereomer were computationally characterized and tested in mGlu₄ pharmacological assays. The results support a VU0155041 active conformation, with the chair cyclohexane having the aromatic amide substituent in an axial position and the carboxylate in an equatorial position. Moreover, the receptor displays enantiomeric discrimination of the chiral PAMs. The constructed pharmacophore characterized a highly constrained mGlu₄ allosteric binding site, thus providing a step forward in structure‐based drug design for mGlu₄ PAMs.