Effect of calcium and magnesium on binding of beta, gamma-methylene ATP to sarcoplasmic reticulum

Isolated sarcotubular membranes (SR) from skeletal muscle bound 3.7 nmol of beta, gamma-methylene [8-3H]ATP (AMP-PCP) per mg of membrane protein. Only one class of binding site was identified and the dissociation constant (K) for this site was 1.5 X 10(-5) M. Addition of 0.05% Triton X-100 increased the number of binding sites to 5.7 nmol/mg. ATP and ADP competitively inhibited AMP-PCP binding. The dissociation constants for ATP and ADP were 3.5 X 10(-5) M and 3.3 X 10(-6) M, respectively. Since this data was obtained in the presence of 5 mM EDTA, it was established that the sarcoplasmic reticulum has a high affinity for the metal free forms of ATP, ADP, and AMP-PCP. Magnesium concentrations in excess of 1 X 10(-4) M inhibited AMP-PCP binding. Lower concentrations of magnesium had little effect on AMP-PCP binding. The effect of calcium on AMP-PCP binding was biphasic. Calcium concentration between 1 X 10(-6) and 1 X 10(-4) M inhibited AMP-PCP binding. Inhibition was maximal at 1 X 10(-5) M. Calcium concentration above 1 X 10(-4) M facilitated analogue binding. Possible sites of magnesium and calcium actions are discussed.     

Selectivity in exposure to information.

2 hypotheses, derived from Festinger's theory of cognitive differences were tested: following a decision, persons tend to seek information that favors the chosen alternative and to avoid information that favors the rejected alternative; and the more important the decision, the greater is the subsequent selectivity in exposure to information. The method involved eliciting attitudes from college students as to various conditions regarding examination procedures. The hypotheses were supported. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Space Time Regularized Zero Forcing in Downlink Code Division Multiple Access Systems with Complementary Codes

Wireless Personal Communications - Complementary coded code-division multiple access (CC-CDMA) has been originated as one of the extremely robust multiuser access technique in designing high data...     

Intraoperative radiotherapy in 1997

Codon usage bias of 1,117 Drosophila melanogaster genes, as well as fewer D. pseudoobscura and D. virilis genes, was examined from the perspective of relative abundance of isoaccepting tRNAs and their changes during development. We found that each amino acid contributes about equally and highly significantly to overall codon usage bias, with the exception of Asp which had very low contribution to overall bias. Asp was also the only amino acid that did not show a clear preference for one of its synonymous codons. Synonymous codon usage in Drosophila was consistent with "optimal" codons deduced from the isoaccepting tRNA availability. Interestingly, amino acids whose major isoaccepting tRNAs change during development did not show as strong bias as those with developmentally unchanged tRNA pools. Asp is the only amino acid for which the major isoaccepting tRNAs change between larval and adult stages. We conclude that synonymous codon usage in Drosophila is well explained by tRNA availability and is probably influenced by developmental changes in relative abundance.     

A predictive screening index for posttraumatic stress disorder and depression following traumatic injury.

Posttraumatic stress disorder (PTSD) and major depressive episode (MDE) are frequent and disabling consequences of surviving severe injury. The majority of those who develop these problems are not identified or treated. The aim of this study was to develop and validate a screening instrument that identifies, during hospitalization, adults at high risk for developing PTSD and/or MDE. Hospitalized injury patients (n = 527) completed a pool of questions that represented 13 constructs of vulnerability. They were followed up at 12 months and assessed for PTSD and MDE. The resulting database was split into 2 subsamples. A principal-axis factor analysis and then a confirmatory factor analysis were conducted on the 1st subsample, resulting in a 5-factor solution. Two questions were selected from each factor, resulting in a 10-item scale. The final model was cross-validated with the 2nd subsample. Receiver-operating characteristic curves were then created. The resulting Posttraumatic Adjustment Scale had a sensitivity of .82 and a specificity of .84 when predicting PTSD and a sensitivity of .72 and a specificity of .75 in predicting posttraumatic MDE. This 10-item screening index represents a clinically useful instrument to identify trauma survivors at risk for the later development of PTSD and/or MDE. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fostering active network management through SMEs’ practises

Managing the electricity network through ‘smart grid’ systems is a key strategy to address challenges of energy security, low carbon transitions and the replacement of ageing infrastructure networks in the UK. Small and medium enterprises (SMEs) have a significant role in shaping patterns of energy consumption. Understanding how their activities interrelate with changes in electricity systems is critical for active network management. A significant challenge for the transformation of electricity systems involves comprehending the complexity that stems from the variety of commercial activities and diversity of social and organizational practises among SMEs that interact with material infrastructures. We engage with SMEs to consider how smart grid interventions ‘fit’ into everyday operational activities. Drawing on analysis of empirical data on electricity use, smart metre data, surveys, interviews and ‘energy tours’ with SMEs to understand lighting, space heating and cooling, refrigeration and IT use, this paper argues for experimenting with the use of practise theory as a framework for bringing together technical and social aspects of energy use in SMEs. This approach reveals that material circumstances and temporal factors shape current energy demand among SMEs, with ‘connectedness’ an emergent factor.     

Successive interference cancellation in asynchronous CC-CDMA systems under Rician fading channels

Telecommunication Systems - The unprecedented frequency diversity gain offered by complementary coded code-division multiple access (CC-CDMA) makes it more attractive than conventional CDMA systems...