bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conformational studies of alanine‐rich peptide using CD and FTIR spectroscopy
Authors: bagińska Katarzyna , Makowska Joanna , Wiczk WiesŁaw , Kasprzykowski Franciszek , ChmurzyńSKI Lech 
Published: October 2007

AbstractThe circular dichroism (CD) and Fourier transform infrared (FTIR) methods were applied to the conformational studies of alanine‐rich peptide Ac‐K‐[A]11‐KGGY‐NH2 (where K is lysine, A is alanine, G is glycine and Y is tyrozyne) in water, methanol (MeOH) and trifluoroethanol (TFE). The analysis of CD‐spectra of the peptide in water at different concentrations revealed that the secondary structure content depends on the peptide concentration and pH of the solution. The increase of the peptide concentration causes a decrease of α‐helix content and, simultaneously, an increase of β‐sheet structure, while the unordered structure is the predominant one. Additional elements are discovered in MeOH and TFE but α‐helix and β‐turns predominate. Moreover, in these solutions the percentage content of the secondary structure does not depend on the temperature. FTIR measurements, carried out at higher peptide concentration (about one order of magnitude) than these CD measurements mentioned above, revealed that in water solution the solid state β‐sheet, and aggregated structures, dominate. However, in TFE the most abundant are α‐helix and β‐turns structures. The thioflavine T assay showed the tendency of the studied peptide for aggregate. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
On informative detection bias in screening studies
Authors: Sjölander Arvid , Humphreys Keith , Palmgren Juni 
Published: October 2007

AbstractThe problem of estimating the effect of hormone replacement therapy (HRT) on breast cancer has attracted much attention in the causal inference literature. It is known that the HRT effect on diagnosis (observed) is potentially larger than the effect on true cancer status (of interest), and that the standard approach (stratification) to deal with this detection bias is not valid when screening pattern and cancer status share common causes. We propose a sensitivity analysis to deal with detection bias, and demonstrate that the earlier proposed approach of data restriction is not valid. Copyright © 2007 John Wiley & Sons, Ltd.
Comparison of algorithms to generate event times conditional on time‐dependent covariates
Authors: Sylvestre Marie‐Pierre , Abrahamowicz Michal 
Published: October 2007

AbstractThe Cox proportional hazards model with time‐dependent covariates (TDC) is now a part of the standard statistical analysis toolbox in medical research. As new methods involving more complex modeling of time‐dependent variables are developed, simulations could often be used to systematically assess the performance of these models. Yet, generating event times conditional on TDC requires well‐designed and efficient algorithms. We compare two classes of such algorithms: permutational algorithms (PAs) and algorithms based on a binomial model. We also propose a modification of the PA to incorporate a rejection sampler. We performed a simulation study to assess the accuracy, stability, and speed of these algorithms in several scenarios. Both classes of algorithms generated data sets that, once analyzed, provided virtually unbiased estimates with comparable variances. In terms of computational efficiency, the PA with the rejection sampler reduced the time necessary to generate data by more than 50 per cent relative to alternative methods. The PAs also allowed more flexibility in the specification of the marginal distributions of event times and required less calibration. Copyright © 2007 John Wiley & Sons, Ltd.
Connection Between Surface Properties, Specific Surface Area and Component Distribution of Binary Mixtures of Corn Starch and Metronidazole
Authors: Tüske Zsófia , László Krisztina , Pintye‐Hódi Klára 
Published: October 2007

AbstractKnowledge of the surface properties of pharmaceutical solids and excipients is of great significance for an understanding of the interactions between the particles of powders and powder mixtures [1, 2] and the accessories of the equipment [3] in the course of various technological procedures, e.g. powder mixing. The mixing of particulate ingredients to achieve content uniformity remains an important question [4]. Our present aims were to investigate the interparticular interactions, the specific surface areas of binary mixtures and of their components, and the visual appearance of the binary mixtures, using a scanning electron microscope. Corn starch is a frequently used excipient in pharmaceutical formulation. Metronidazole is one of the active agents with high dose. To find the optimal active ingredient and excipient proportion with homogeneous distribution is in this case a very important question. Surface free energy, adhesion and cohesion work may be calculated in various simply ways. In view of the surface properties of a binary mixture and that of the components the particle distribution can be characterized.
Aging Effects on Sorbitol‐ and Non‐Crystallizing Sorbitol‐Plasticized Tapioca Starch Films
Authors: Thirathumthavorn Doungjai , Charoenrein Sanguansri 
Published: October 2007

AbstractThe effect of aging on the properties of tapioca starch films plasticized with either sorbitol (S) or non‐crystallizing sorbitol (NCS) was investigated in this study. Tapioca starch, plasticizer and deionized water were mixed, heated, cast on high‐density polyethylene plates and dried at ambient conditions. The results showed that S was more effective in plasticizing fresh starch film than NCS. However, sorbitol crystallization was observed in S‐plasticized starch film after one month of storage, while there was no crystallization observed in NCS‐plasticized starch film after two months of storage. Mechanical properties of both S‐ and NCS‐plasticized starch films changed significantly with time, but with less change in the NCS‐plasticized films. Tensile strength, elastic modulus and toughness increased over time; conversely, elongation decreased. Additionally, the water vapor transmission rate decreased as storage time increased. The fact that mechanical properties of both S‐ and NCS‐plasticized films changed is likely due to an increase in crystallinity of the starch in the films with time.
Industrial Demand for Cassava Starch in India
Authors: Srinivas Tavva 
Published: October 2007

AbstractCassava (Manihot esculenta crantz) is a staple food crop cultivated in several developing countries. Cassava is consumed either directly as cooked tubers or as the products prepared from cassava. Cassava in India is used mainly in the human consumption, industrial and animal feed sectors. In India nearly 60% of cassava is used industrially in the production of sago, starch and dry chips. The presented study has clearly indicated that the future of cassava in India lies in its diversified uses in the industrial sector. The projected demand is predominantly in the adhesive sector, especially in the corrugation gums and paper conversion industry, and in the paper industry. The projected demand‐supply gap in the industrial sector is expected to be 1.5×106 t of cassava tubers requiring another 750 000 ha to be brought under cassava cultivation. New and potential areas in the non‐traditional cassava‐growing states are to be considered for area expansion.
Labeled brassinosteroids for biochemical studies
Authors: Khripach Vladimir , Zhabinskii Vladimir 
Published: October 2007

AbstractThe present paper describes the results of our studies on the synthesis of brassinolide biosynthetic precursors as tools for investigations of new biosynthetic routes leading to brassinosteroids. The corresponding labeled compounds containing three or six deuterium atoms at terminal methyl group(s) of the side chain (in a position ensuring lack of isotopic exchange) were prepared starting from stigmasterol or bisnorcholenic acid. Two strategies for the construction of the carbon skeleton of the side chain were applied in this study: Claisen rearrangement of allylic alcohols and convergent synthesis based on the coupling of 22‐aldehydes with appropriate chiral sulfone. More than 20 brassinolide precursors (actual or suspected) have been prepared for metabolic studies that enabled identification of new brassinosteroids and biosynthetic subpathways to brassinolide in Secale cereale and Arabidopsis thaliana. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 265–274; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20123
Hexacoordinated phosphates: how to teach old chiral anions new asymmetric tricks
Authors: Lacour Jerome , Linder David 
Published: October 2007

AbstractChemical reactions and processes often involve chiral, yet racemic, cationic reagents, intermediates, or products. To afford instead nonracemic or enantiopure compounds, an asymmetric ion pairing of the cations with enantiopure anions can be considered—the counter ions behaving as asymmetric auxiliaries, ligands, or reagents. Detailed herein is a short review of our approach toward gaining reliable and predictable control over stereoselective ion pairing phenomena through the synthesis and use of novel configurationally stable hexacoordinated phosphate anions. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 275–285; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20124
Rational design of light‐controllable polymer micelles
Authors: Zhao Yue 
Published: October 2007

AbstractAmphiphilic block copolymer (BCP) micelles are nanocarriers that hold promise for controlled delivery applications. This account highlights our recent works on light‐dissociable BCP micelles. We have designed and developed light‐responsive amphiphilic BCPs whose micellar aggregates (core‐shell micelles and vesicles) can be disrupted by light exposure. The basic strategy is to incorporate a chromophore into the structure of the hydrophobic block, whose photoreaction can result in a conformational or structural change that shifts the hydrophilic/hydrophobic balance toward the destabilization of the micelles. Using various chromophores including azobenzene, pyrene and nitrobenzene, we have achieved both reversible and irreversible dissociation of BCP micelles upon illumination with UV/visible or near infrared light. The demonstrated rational design principle based on light‐changeable or light‐switchable amphiphilicity is general and can be applied to many polymer/chromophore combinations. This opens the door to developing photocontrollable polymer nanocarriers offering control over when and where the release of loaded agents takes place. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 286–294; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20127
An overview of how sports, out‐of‐school time, and youth well‐being can and do intersect
Authors: Le Menestrel Suzanne , Perkins Daniel F. 
Published: October 2007

AbstractThis article examines the benefits and disadvantages of participation in organized youth sports and describes a youth development approach to sports programming. The authors summarize what is known about the physical, socioemotional, and cognitive benefits of sports participation. These include health benefits (for example, a reduction in heart disease and diabetes) as well as socioemotional benefits, among them the coping skills of being able to bounce back from problems. The authors describe some of the disadvantages of participation as well. In particular, studies in this area have focused on health risk behaviors and engagement in problem behaviors. The authors present an innovative approach to youth sports and the advantages of implementing this approach using the emerging community youth development framework. Specific examples of youth sports programs are provided that use a positive youth development framework.
Improving health through youth sports: Is participation enough?
Authors: Bergeron Michael F. 
Published: October 2007

AbstractThe health benefits of engaging in regular physical activity are widely known: enhanced cardiorespiratory fitness, increased muscular strength and endurance, and favorable cholesterol and other profiles. Nevertheless, particularly in youth sports programs run by volunteer, and perhaps inadequately trained, coaches, many youth may not realize the health benefits of sports participation due to a number of factors, among them, inappropriate coach‐child ratios, limited space, or mismatched expectations between coaches and those of children and their parents. There are specific strategies that can be implemented to ensure that youth receive the maximize benefits from participation in sports. These strategies are presented in the following areas: frequency, intensity, and duration; cross‐training or complementary exercise; access points; utilization of space and time; nutrition; and rest. For instance, with regard to the frequency of physical activity, some sports, including soccer, basketball, and singles tennis, require extensive physical effort over an extended period of time, while others, such as baseball and football, have a lot of downtime. Thus, in order for children and youth to meet the recommendation of participating in moderate or vigorous physical activity at least four times per week, sports programs need to have opportunities for all athletes to practice hard. Finally, the author discusses the point at which participation in sports might be too much, leading to significant injuries, frustration, and resentment.
Cooperation versus competition: Is there really such an issue?
Authors: Daniels Ann Michelle 
Published: October 2007

AbstractThis author argues that youth sports can move beyond the dichotomy of cooperation versus competition by redefining competition. This can be accomplished by considering the development of cooperative skills and achievement motivation. The article addresses how cooperative skills can be taught within a competitive sport. First, it is important to understand how children and youth understand and process competition based on their developmental stage. Parents need to consider whether a child is mentally, emotionally, socially, and physically mature enough to participate in an organized sport. Readiness for a sport is just as important as readiness for school. Teaching cooperative skills within a competitive context involves a focus on personal development rather than performance. By asking themselves a series of developmental questions, such as, “Is the sport appropriate for the developmental age of the child?” parents and coaches can form realistic expectations of young athletes. Motivation is also a key determinant of a child's readiness for youth sports and competition. Children want to play a sport when they feel competent. It is up to parents and coaches to create a motivational climate that is focused on doing one's best and not on external rewards like winning. Children and youth receive specific and constructive feedback that focuses on improvement in this type of climate. The author also discusses three models of competition: the military model, the reward model, and the partnership model. The partnership model is the approach that balances competition in youth sports. The author concludes by introducing the “athletic square” model as an important and appropriate way to promote youth sports.
Youth sport as a component of organized afterschool programs
Authors: Coatsworth J. Douglas , Conroy David E. 
Published: October 2007

AbstractOrganized afterschool programs have received increased attention over the past two decades because of changes in family demographics and in society's structures for supervising and socializing youth. The number of afterschool programs has been rapidly expanding to meet the increased need. However, not all youth in need are being reached, and the programs that are being created are loosely connected. The authors present several advantages of more fully integrating sport and afterschool activities. There are well‐documented positive effects of physical activity and sports participation on physical and psychosocial youth outcomes, especially if those programs are implemented with these points in mind. Promoting healthy lifestyles and preventing obesity are also important federal‐ and state‐level policy priorities. Finally, physical activity and fitness and sport participation are linked with improved cognitive functioning and greater academic achievement, two desired outcomes of many afterschool programs. The authors note, however, that many youth sports programs designed to enhance positive youth development will not succeed without more attention focused on improving them, because they do not use best practices and principles of afterschool and youth sports programs. The authors focus on best practice ideas in four areas that are essential to the successful intersection of youth sport and afterschool programming: setting a clear mission, programming with appropriate content, staff training, and research and evaluation or frequent assessments. They illustrate best practices in each of these areas using program descriptions and provide recommendations for strengthening the connections among afterschool programs, sports, and physical activity.
Characteristics of sports‐based youth development programs
Authors: Perkins Daniel F. , Noam Gil G. 
Published: October 2007

AbstractThe term “sports‐based youth development programs” is coined and defined in the context of the community youth development framework. Sports‐based youth development programs are out‐of‐school‐time programs that use a particular sport to facilitate learning and life skill development in youth. Community youth development programs use a community youth development approach to create opportunities for youth to connect to others, develop skills, and use those skills to contribute to their communities. This, in turn, increases their ability to succeed. The authors describe how sports‐based youth development programs can be contexts that promote positive youth development. The features of positive developmental settings for youth from the work of the National Research Council and the Institute of Medicine, as well as the features identified by other researchers, are presented in the context of sports‐based youth development programs. For example, a sports program that provides appropriate structure has delineated clear rules, expectations, and responsibilities for youth, parents, coaches, officials, and other organizers.
Disruption of genes encoding pyruvate dehydrogenase kinases leads to retarded growth on acetate and ethanol in Saccharomyces cerevisiae
Authors: Yde Steensma H. , Tomaska Lubomir , Reuven Peter , Nosek Jozef , Brandt Raymond 
Published: October 2007

AbstractTwo open reading frames, YIL042c (PKP1) and YGL059w, with 25% sequence similarity to human pyruvate dehydrogenase kinases, were shown to have protein kinase activity. Using GFP fusions, it was demonstrated that the proteins localize in discrete submitochondrial regions. Strains with a null mutation in these loci grew poorly on acetate and ethanol as carbon sources. Doubling times increased from ca. 4 h in the wild‐type to > 6 h for the mutants. Growth rates of the mutants could be restored to wild‐type levels by simultaneous disruption of the PDA1 gene, encoding the E1α subunit of the pyruvate dehydrogenase complex. This observation and the pyruvate dehydrogenase activities measured in the mutant strains and the wild‐type grown on glucose or acetate suggest that the slow growth phenotype on C2 carbon sources is caused by a futile cycle in which phosphoenolpyruvate is converted back to acetyl coenzyme A. Copyright © 2007 John Wiley & Sons, Ltd.
Identification and characterization of amidase‐ homologous AMI1 genes of bottom‐fermenting yeast
Authors: Yoshida Satoshi , Hashimoto Kaori , Tanaka‐Kanai Keiko , Yoshimoto Hiroyuki , Kobayashi Osamu 
Published: October 2007

AbstractIt has been proposed that a bottom‐fermenting yeast strain of Saccharomyces pastorianus is a natural hybrid between S. cerevisiae and S. bayanus and possesses at least two types of genome. In the process of conducting expressed sequence tag (EST) analysis, we isolated bottom‐fermenting yeast‐specific (BFY) genes that have no significant homology with sequences in the S288C database. One of the BFY genes, AMI1, encodes a protein with homology to an amidase conserved among plants, Bacillus subtilis, Neurospora crassa, Schizosaccharomyces pombe and Saccharomyces species, with the exception of S. cerevisiae S288C. In the bottom‐fermenting yeast, three alleles of AMI1 (one AMI1‐A and two AMI1‐B alleles) were found on different chromosomes. AMI1‐A on chromosome XIII is most homologous to the S. bayanus AMI1 gene, while AMI1‐B on chromosome X is most homologous to the Saccharomyces paradoxus AMI1 gene. Overproduction of AMI1 in S. cerevisiae resulted in a slow‐growth phenotype. Although a hydropathy plot shows that Ami1p has a putative signal sequence, it was located in the cell, not secreted into the medium. By metabolome analysis of intracellular compounds, the amount of histidine and arginine is increased, and the amount of threonine, lysine and nicotinic acid is decreased in the Ami1p‐overproducing strain as compared with the control, suggesting that Ami1p may hydrolyse some amides related to amino acid and niacin metabolism in the cell. The nucleotide sequence data reported in this paper appear in the DDBJ/EMBL/GenBank nucleotide database under Accession Nos AB195821 and AB195822. Copyright © 2007 John Wiley & Sons, Ltd.
Community‐based Practices: Integrating Dissemination Theory with Critical Theories of Power and Justice
Authors: Sandler Jen 
Published: October 2007

AbstractThis paper critically reviews two diverse intellectual traditions concerned with community‐based interventions: the literature on dissemination of community interventions and the critical psychology literature that is concerned with systemic power inequalities and structural injustice. The dominant dissemination‐of‐innovations framework has shifted toward an emphasis on community, yet it does not generally take into account issues of power and inequality within the diverse community spheres into which interventions are disseminated. On the other hand, critical psychologists, who have concerned themselves with both understanding and addressing issues of power and structural injustice, have tended to eschew the possibility of standardizing and making transferable practices, programs, and even processes that address these issues in particular settings. This paper traces and critiques both sides of this divide within community psychology, positing a framework to bring these diverse intellectual resources together so that community interventions might fruitfully be examined in terms of theircommunity‐based practices, or practices that bear on structural injustice. This framework is illustrated with a case study of the community‐based practices of a widely disseminated evidence‐based community intervention.