Home About us Contact
|
Home About us Contact | ||
|
|
||
Slight Advantage (slight + advantage)
Selected AbstractsAccurate prediction of protonation state as a prerequisite for reliable MM-PB(GB)SA binding free energy calculations of HIV-1 protease inhibitorsJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 5 2008Kitiyaporn Wittayanarakul Abstract Binding free energies were calculated for the inhibitors lopinavir, ritonavir, saquinavir, indinavir, amprenavir, and nelfinavir bound to HIV-1 protease. An MMPB/SA-type analysis was applied to conformational samples from 3 ns explicit solvent molecular dynamics simulations of the enzyme-inhibitor complexes. Binding affinities and the sampled conformations of the inhibitor and enzyme were compared between different HIV-1 protease protonation states to find the most likely protonation state of the enzyme in the complex with each of the inhibitors. The resulting set of protonation states leads to good agreement between calculated and experimental binding affinities. Results from the MMPB/SA analysis are compared with an explicit/implicit hybrid scheme and with MMGB/SA methods. It is found that the inclusion of explicit water molecules may offer a slight advantage in reproducing absolute binding free energies while the use of the Generalized Born approximation significantly affects the accuracy of the calculated binding affinities. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008 [source] Affirmative Districting and Four Decades of Redistricting: The Seats/Votes Relationship 1972-2008POLITICS & POLICY, Issue 2 2010THEODORE S. ARRINGTON How has the partisan seat/vote relationship in U.S. congressional elections changed in the four reapportionment cycles since 1970? Concern about a biased and unresponsive districting system and "vanishing marginals" has increased because of the affirmative districting to create minority-majority districts after 1990. The 1990 redistricting cycle did not give Republicans an unfair advantage in the seat/vote relationship nationwide or in the southern states, but it may have reduced a previous Democratic bias. The 2000 cycle may have given the GOP a slight advantage. More recent districting cycles with affirmative districting have increased both the responsiveness of congressional elections and the number of opposed contests. ¿Cuánto ha cambiado la relación asiento/voto en las elecciones estadounidenses al congreso en los cuatro ciclos de redistritación desde 1970? La preocupación de que emerja un sistema de redistritación poco conducente a la responsabilidad legislativa ante el electorado ha incrementado a causa de rediseño afirmativo de distritos mayoría-minoría después de 1990. El ciclo de redistritación de 1990 no les brindó a los Republicanos una ventaja injusta en la relación asiento/voto a nivel nacional o en los estados sureños, pero pudo haber reducido la inercia electoral que venía favoreciendo a los Demócratas. El ciclo del año 2000 pudo haberle dado al Partido Republicano una leve ventaja. A partir de estos hallazgos sostenemos que ciclos de redistritación reciente, con un rediseño afirmativo, han incrementado tanto la responsabilidad legislativa ante el electorado, como el número de los contendientes electorales. [source] Absence of Iatrogenic or Contagion Effects in Adolescent Group Therapy: Findings from the Cannabis Youth Treatment (CYT) StudyTHE AMERICAN JOURNAL ON ADDICTIONS, Issue 2006Joseph A. Burleson PhD Though widely used and presumed effective in practice, some scholars (Dishion et al., 1999) have raised the concern that group therapy for adolescents with substance use disorder and a range of deviancy has the potential for causing iatrogenic effects (e.g., increased substance use, behavior and legal problems) for those with low deviancy. Using data from 400 youth in the largest adolescent treatment experiment conducted to date (Dennis et al., 2004), this study shows that group composition in terms of conduct disorder symptoms is not associated with worse substance use, psychological, environmental or legal treatment outcomes. The results actually indicated that there was a slight advantage for youth with high conduct disorder to be included in the groups with less symptoms. The results appear consistent with recent meta-analyses of delinquency studies (Lipsey, 2006) which have found no evidence of iatrogenic effects. These results support the common clinical belief that group therapy for youths with substance use disorders is a safe and effective treatment modality. [source] Optimum Tension for Partial Ossicular Replacement Prosthesis Reconstruction in the Human Middle Ear,THE LARYNGOSCOPE, Issue 2 2004David P. Morris BSc Abstract Objective: Hearing results from ossiculoplasty are unpredictable. There are many potentially modifiable parameters. One parameter that has not been adequately investigated in the past is the effect of tension on the mechanical functioning of the prosthesis. Our goal was to investigate this parameter further, with the hypothesis that the mechanical functioning of partial ossicular replacement prostheses (PORP) from the stapes head to the eardrum will be affected by the tension that they are placed under. Methods: Fresh temporal bones were used to reconstruct a missing incus defect with a PORP-type prosthesis. Three different lengths of PORP were used, and the stapes vibrations were measured with a laser Doppler vibrometer using a calibrated standard sound in the ear canal. Eight temporal bones were used. Results: Tension had a very significant effect on stapes vibration. In general, loose prostheses resulted in the best overall vibration transmission. The effects were most marked at the lower frequencies. There was a slight advantage to tight prostheses in the higher frequencies, but much less than the decrement in lower frequencies with tight prostheses. Conclusion: In ossicular reconstruction, best stapes vibration results in our model are achieved by shorter prostheses, which result in lower tension. [source] Optimization of fed-batch parameters and harvest time of CHO cell cultures for a glycosylated product with multiple mechanisms of inactivationBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2007Ryan S. Senger Abstract Optimization of fed-batch feeding parameters was explored for a system with multiple mechanisms of product inactivation. In particular, two separate mechanisms of inactivation were identified for the recombinant tissue-type activator (r-tPA) protein. Dynamic inactivation models were written to describe particular r-tPA glycoform inactivation in the presence and absence of free-glucose. A glucose-independent inactivation mechanism was identified, and inactivation rate constants were found dependent upon the presence of glycosylation of r-tPA at N184. Inactivation rate constants of the glucose-dependent mechanism were not affected by glycosylation at N184. Fed-batch optimization was performed for r-tPA production by CHO cell culture in a stirred-tank reactor with glucose, glutamine and asparagine feed. Feeding profiles in which culture supernatant concentrations of free-glucose and amino acids (combined glutamine and asparagine) were used as control variables, were evaluated for a wide variety of set points. Simulation results for a controlled feeding strategy yielded an optimum at set points of 1.51 g L,1 glucose and 1.18 g L,1 of amino acids. Optimization was also performed in absence of metabolite control using fixed feed-flow rates initiate during the exponential growth phase. Fixed feed-flow results displayed a family of optimum solutions along a mass flow rate ratio of 3.15 of glucose to amino acids. Comparison of the two feeding strategies showed a slight advantage of rapid feeding at a fixed flow rate as opposed to metabolite control for a product with multiple mechanisms of inactivation. Biotechnol. Bioeng. 2007;98: 378,390. © 2007 Wiley Periodicals, Inc. [source] Multilocus ribosomal RNA phylogeny of the leaf beetles (Chrysomelidae)CLADISTICS, Issue 1 2008Jesús Gómez-Zurita Basal relationships in the Chrysomelidae (leaf beetles) were investigated using two nuclear (small and partial large subunits) and mitochondrial (partial large subunit) rRNA (, 3000 bp total) for 167 taxa covering most major lineages and relevant outgroups. Separate and combined data analyses were performed under parsimony and model-based tree building algorithms from dynamic (direct optimization) and static (Clustal and BLAST) sequence alignments. The performance of methods differed widely and recovery of well established nodes was erratic, in particular when using single gene partitions, but showed a slight advantage for Bayesian inferences and one of the fast likelihood algorithms (PHYML) over others. Direct optimization greatly gained from simultaneous analysis and provided a valuable hypothesis of chrysomelid relationships. The BLAST-based alignment, which removes poorly aligned sequence segments, in combination with likelihood and Bayesian analyses, resulted in highly defensible trees obtained in much shorter time than direct optimization, and hence is a viable alternative when data sets grow. The main taxonomic findings include the recognition of three major lineages of Chrysomelidae, including a basal "sagrine" clade (Criocerinae, Donaciinae, Bruchinae), which was sister to the "eumolpine" (Spilopyrinae, Eumolpinae, Cryptocephalinae, Cassidinae) plus "chrysomeline" (Chrysomelinae, Galerucinae) clades. The analyses support a broad definition of subfamilies (i.e., merging previously separated subfamilies) in the case of Cassidinae (cassidines + hispines) and Cryptocephalinae (chlamisines + cryptocephalines + clytrines), whereas two subfamilies, Chrysomelinae and Eumolpinae, were paraphyletic. The surprising separation of monocot feeding Cassidinae (associated with the eumolpine clade) from the other major monocot feeding groups in the sagrine clade was well supported. The study highlights the need for thorough taxon sampling, and reveals that morphological data affected by convergence had a great impact when combined with molecular data in previous phylogenetic analyses of Chrysomelidae. © The Willi Hennig Society 2007. [source] Causes of Male Excess Mortality: Insights from Cloistered PopulationsPOPULATION AND DEVELOPMENT REVIEW, Issue 4 2003Marc Luy The degree to which biological factors contribute to the existence and the widening of mortality differences by sex remains unclear. To address this question, a mortality analysis for the years 1890 to 1995 was performed comparing mortality data on more than 11,000 Catholic nuns and monks in Bavarian communities living in very nearly identical behavioral and environmental conditions with life table data for the general German population. While the mortality differences between women and men in the general German population increased considerably after World War II, they remained almost constant among the members of Bavarian religious orders during the entire observation period, with slight advantages for nuns. Thus, the higher differences observable in the general population cannot be attributed to biological factors. The different trends in sex-specific mortality between the general and the cloistered populations are caused exclusively by men in the general population who were unable to follow the trend in mortality reduction of women, nuns, and especially monks. Under the special environmental conditions of nuns and monks, biological factors appear to confer a maximum survival advantage for women of no more than one year in remaining life expectancy at young adult ages. [source] Economic Crisis and Economic Theory,THE ECONOMIC RECORD, Issue 2010MARK WEDER Two dynamic general equilibrium economies compete in explaining the United States' interwar business cycles. Despite the demand driven contender's slight advantages, the results remain too close to call a clear winner. [source] Determination of quinocide as impurity in primaquine tablets by capillary zone electrophoresisBIOMEDICAL CHROMATOGRAPHY, Issue 5 2009Abdalla A. Elbashir Abstract A capillary zone electrophoretic method has been developed and validated for the determination of the impurity quinocide (QC) in the antimalarial drug primaquine (PQ). Different buffer additives such as native cyclodextrins and crown ethers were evaluated. Promising results were obtained when either , -cyclodextrin (, -CD) or 18-crown-6 ether (18C6) were used. Their separation conditions such as type of buffer and its pH, buffer additive concentration, applied voltage capillary temperature and injection time were optimized. The use of 18C6 offers slight advantages over , -CD such as faster elution times and improved resolution. Nevertheless, migration times of less than 5 min and resolution factors (Rs) in the range of 2,4 were obtained when both additives were used. The method was validated with respect to selectivity, linearity, limits of detection and quantitation, analytical precision (intra- and inter-day variability) and repeatability. Concentrations of 2.12 and 2.71% (w/w) of QC were found in pharmaceutical preparations of PQ from two different manufacturers. A possible mechanism for the successful separation of the isomers is also discussed. Copyright © 2008 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||