bluuebunny/crossref_metadata_2025_split huggingface dataset:
A structural comparison between state and trait self‐regulation models
Authors: Hong Eunsook 
Published: June 2007

AbstractState and trait‐regulation models were compared in 315 eleventh‐graders using simultaneous confirmatory factor analysis. Each of the first‐, second‐, and third‐order factor models was found to describe the data from both state and trait measures well. In both state and trait self‐regulation models, the third‐order factor, self‐regulation, is composed of metacognition and effort, and the second‐order factor, metacognition, is composed of awareness, cognitive strategy, planning, and self‐checking. Findings of invariant factor loadings and factor correlations across state and trait measures indicate that the state and trait self‐regulatory factor structures are similar. Unlike the state‐trait distinctions found in affective personality domain, clear state‐trait distinction was not found in this cognitive domain. In both measures, students who engaged more frequently in metacognitive activities and effort use in their mathematical problem solving performed better than those who did not.
Interaction control of robotic manipulators via second‐order sliding modes
Authors: Ferrara Antonella , Lombardi Cesare 
Published: June 2007

AbstractThis paper deals with the interaction control of robot manipulators. The ideal goal is to control the manipulator so that its end‐effector reaches a desired position in the operative space. The attainment of this goal can be prevented by the fact that during its motion the end‐effector can interact with the environment. So, a realistic goal is regarded as control objective in the paper, that of asymptotically reaching an equilibrium position jointly determined by the choice of the ideal desired position, and by the presence of the environment. The model of the manipulator is supposed to be affected by uncertainties, so that a classical impedance control scheme cannot be adopted. The approach proposed in this paper relies on the theory of sliding mode control. In general, this methodology is deemed nonappropriate to control mechanical systems like robot manipulators, since it introduces the so‐called chattering phenomenon, which produces undesired wear and vibrations. Yet, the final control solution proposed in this paper is based on the generation of sliding modes of the second order, which practically reduces the degradation of performances, and the mechanical stress due to the chattering effect. Indeed, the proposed second‐order sliding mode control scheme relies on the use of a continuous control law, in contrast to conventional sliding mode control schemes. Copyright © 2007 John Wiley & Sons, Ltd.
Hydroxynitrile Lyase in Organic Solvent‐Free Systems to Overcome Thermodynamic Limitations
Authors: von Langermann Jan , Mell Annett , Paetzold Eckhard , Daußmann Thomas , Kragl Udo 
Published: June 2007

AbstractThe overcoming of thermodynamic limitations in the synthesis of optically active ketone cyanohydrins by using organic solvent‐free systems has been investigated. Therefore, substrates with known unfavorable results within hydroxynitrile lyase‐catalyzed reactions were selected for the determination of limitations and bottlenecks in ketone cyanohydrin synthesis. The highly (S)‐selective hydroxynitrile lyase from Manihot esculenta (MeHNL) has been chosen for the conversion of acetophenone and the corresponding derivatives, which are substrates that exhibit only low grades of conversion also with several other hydroxynitrile lyases. With organic solvent‐free systems under optimized reaction conditions conversions up to 78 % with>99.0 ee (S) were obtained. Finally, 5 mL of (S)‐acetophenone cyanohydrin with an enantiomeric excess of 98.5 % ee (S) were synthesized.
Optimization of the Kinetic Resolution of the dl‐Phosphomonoesters of Threonine and Serine by Random Mutagenesis of the Acid Phosphatase from Salmonella enterica
Authors: van Herk Teunie , Hartog Aloysius F. , Ruijssenaars Harald J. , Kerkman Richard , Schoemaker Hans E. , Wever Ron 
Published: June 2007

AbstractAcid phosphatases are enzymes with a broad substrate specificity showing hydrolytic activity towards several different organic phosphate monoesters, such as nucleotides and sugar phosphates. The acid phosphatase from Salmonella enterica ser. typhimurium LT2 (PhoN‐Se) is able to hydrolyze O‐phospho‐dl‐threonine to yield L‐threonine with a very high enantioselectivity (E>200). When O‐phospho‐dl‐serine was hydrolyzed by PhoN‐Se, D‐serine was formed, however, the ee values rapidly dropped to 50 %. Random mutagenesis by error‐prone PCR was performed on the phosphatase in order to increase its enantioselectivity in the formation of D‐serine. Two variants with increased selectivity from a library of 9600 mutants have been found, N151D and V78L showing E values of 18.1 and 4.1, respectively, compared to 3.4 for the wild‐type (WT) enzyme.
Real‐Time Imaging of Protease Action on Substrates Covalently Immobilised to Polymer Supports
Authors: Deere Joseph , McConnell Gail , Lalaouni Antonia , Maltman Beatrice A. , Flitsch Sabine L. , Halling Peter J. 
Published: June 2007

AbstractWe report for the first time single bead spatially resolved activity measurements of solid‐phase biocatalytic systems followed in real‐time. Trypsin cleavage of Bz‐Arg‐OH and subtilisin cleavage of Z‐Gly‐Gly‐Leu‐OH each liberate a free amino group on aminocoumarin covalently immobilised to PEGA1900 beads [a co‐polymer of poly(ethylene glycol) with molecular mass of 1900 cross‐linked with acrylamide]. This restores fluorescence which is imaged in optical sections by two‐photon microscopy. For trypsin cleavage, fluorescence is restricted initially to surface regions, with more than 1 hour needed before reaction is fully underway in the bead centre, presumably reflecting slow enzyme diffusion. In contrast, for subtilisin cleavage fluorescence develops throughout the bead more quickly.
Hydrolase‐Catalysed Preparation of Chiral α,α‐Disubstituted Cyanohydrin Acetates
Authors: Holt Jarle , Arends Isabel W. C. E. , Minnaard Adriaan J. , Hanefeld Ulf 
Published: June 2007

AbstractThe enzymatic hydrolysis of esters of tertiary alcohols has long been a challenge. In particular their kinetic resolutions have virtually not been addressed. Here we describe the successful kinetic resolution of α,α‐disubstituted cyanohydrin acetates, a type of protected tertiary alcohols that form particularly interesting building blocks in organic synthesis. Utilising Subtilisin A the hydrolysis reaction was (S)‐selective, while Candida rugosa lipase was (R)‐selective. With these commercially available enzymes both enantiomers of the α,α‐disubstituted cyanohydrin acetates are now accessible.
Chemoenzymatic Synthesis of Glycolic Acid
Authors: Panova Anna , Mersinger Lawrence J. , Liu Qiang , Foo Thomas , Roe D. Christopher , Spillan William L. , Sigmund Amy E. , Ben‐Bassat Arie , Wagner L. Winona , O'Keefe Daniel P. , Wu Shijun , Petrillo Kelly L. , Payne Mark S. , Breske Stephen T. , Gallagher F. Glenn , DiCosimo Robert 
Published: June 2007

AbstractA chemoenzymatic process for the production of high‐purity glycolic acid has been demonstrated, starting with the reaction of formaldehyde and hydrogen cyanide to produce glycolonitrile in >99 % yield and purity. The resulting aqueous glycolonitrile was used without further purification in a subsequent biocatalytic conversion of glycolonitrile to ammonium glycolate. A high‐activity biocatalyst based on an Acidovorax facilis 72W nitrilase was developed, where protein engineering and optimized protein expression in an E. coli transformant host were used to improve microbial nitrilase specific activity by 33‐fold compared to the wild‐type strain. A biocatalyst productivity of >1000 g glycolic acid/g dry cell weight was achieved using a glutaraldehyde/polyethylenimine cross‐linked carrageenan‐immobilized E. coli MG1655 transformant expressing the A. facilis 72W nitrilase mutant, where 3.2 M ammonium glycolate was produced in consecutive batch reactions with biocatalyst recycle, or in a continuous stirred‐tank reactor. Direct conversion of the unpurified ammonium glycolate product solution to high‐purity aqueous glycolic acid was accomplished by fixed‐bed ion exchange over a strong acid cation resin.
Comparing the Stereoselective Biooxidation of Cyclobutanones by Recombinant Strains Expressing Bacterial Baeyer–Villiger Monooxygenases
Authors: Rudroff Florian , Rydz Joanna , Ogink Freek H. , Fink Michael , Mihovilovic Marko D. 
Published: June 2007

AbstractMicrobial Baeyer–Villiger oxidation of representative prochiral ketones with a cyclobutanone structural motif was investigated using a collection of eight monooxygenases of different bacterial origin. This platform of enzymes is able to perform stereoselective biotransformations on an array of structurally diverse substrates. With several ketone precursors, biooxidations yielded enantiocomplementary butyrolactones as key intermediates for the synthesis of natural products and bioactive compounds. The microbial Baeyer–Villiger oxidation allows a facile and rapid entry to several compound classes in a desymmetrization reaction upon de novo generation of chirality.
Enzyme Immobilization: The Quest for Optimum Performance
Authors: Sheldon Roger A. 
Published: June 2007

AbstractImmobilization is often the key to optimizing the operational performance of an enzyme in industrial processes, particularly for use in non‐aqueous media. Different methods for the immobilization of enzymes are critically reviewed. The methods are divided into three main categories, viz. (i) binding to a prefabricated support (carrier), (ii) entrapment in organic or inorganic polymer matrices, and (iii) cross‐linking of enzyme molecules. Emphasis is placed on relatively recent developments, such as the use of novel supports, e.g., mesoporous silicas, hydrogels, and smart polymers, novel entrapment methods and cross‐linked enzyme aggregates (CLEAs).
Efficient Synthesis of Either Enantiomer of Ethyl 5‐Hydroxyhept‐6‐enoate
Authors: Fischer Thomas , Pietruszka Jörg 
Published: June 2007

AbstractThe application of alcohol dehydrogenases as a key‐step for the synthesis of the title compound is reported. 5‐Hydroxyhept‐6‐enoates are versatile intermediates, e.g., for the synthesis of a variety of arachidonic acid metabolites.
A periodical replacement model based on cumulative repair‐cost limit
Authors: Lai Min‐Tsai 
Published: June 2007

AbstractThis paper considers a periodical replacement model based on a cumulative repair‐cost limit, whose concept uses the information of all repair costs to decide whether the system is repaired or replaced. The failures of the system can be divided into two types. One is minor failure that is assumed to be corrected by minimal repair, while the other is serious failure where the system is damaged completely. When a minor failure occurs, the corresponding repair cost is evaluated and minimal repair is then executed if this accumulated repair cost is less than a pre‐determined limit L, otherwise, the system is replaced by a new one. The system is also replaced at scheduled time T or at serious failure. Long‐run expected cost per unit time is formulated and the optimal period T* minimizing that cost is also verified to be finite and unique under some specific conditions. Copyright © 2007 John Wiley & Sons, Ltd.
A simple Markov chain structure for the evolution of credit ratings
Authors: Baíllo Amparo , Fernández José Luis 
Published: June 2007

AbstractWe focus on continuous Markov chains as a model to describe the evolution of credit ratings. In this work it is checked whether a simple, tridiagonal type of generator provides a good approximation to a general one. Three different tridiagonal approximations are proposed and their performance is checked against two generators, corresponding to a volatile and a stable period, respectively. Copyright © 2007 John Wiley & Sons, Ltd.
Nachweis der erforderlichen Ankerlänge mit der Finite‐Elemente‐Methode
Authors: Perau Eugen 
Published: June 2007

AbstractIn diesem Beitrag wird zunächst die statische Wirkungsweise von Verankerungen für Baugrubenwände und die damit verbundene Notwendigkeit zur Einhaltung von Mindestlängen der Anker analysiert. Der zugehörige Nachweis der erforderlichen Ankerlänge soll nach DIN 1054:2005‐01 mit einem Verfahren der klassischen Erdstatik, dem “Nachweis der Standsicherheit in der tiefen Gleitfuge”, geführt werden.Obwohl die Finite‐Elemente‐Methode (FEM) für Standsicherheitsnachweise nur in Ausnahmefällen eingesetzt wird und die einschlägigen Empfehlungen, EAU und EAB das Führen dieses Nachweises mit der FEM nicht vorsehen, erscheint ein solches Vorgehen durchaus denkbar.Es wird in dem vorliegenden Beitrag anhand eines Beispiels gezeigt, welcher Bedeutung der Nachweis der ausreichenden Ankerlänge und somit auch der “Standsicherheit in der tiefen Gleitfuge” bei Nachweisen auf Basis der FEM zukommt und wie ein Nachweis der ausreichenden Ankerlänge dann aussehen könnte. Den Abschluss des Beitrags bildet die Variation der Biegesteifigkeit und der Biegefestigkeit der Verbauwand. Es lässt sich daraus ableiten, dass bei einem FEM‐basierten Nachweis auch das Verformungsverhalten der Wand einen erheblichen Einfluss auf die berechnete Standsicherheit einer verankerten Baugrubenwand besitzt.
Rissmonitoring von Betonoberflächen unter Verwendung digitaler Bildanalyseverfahren
Authors: Avak Ralf , Schwuchow Ronald , Franz Marcel 
Published: June 2007

AbstractGegenwärtig werden Risse und Rissbreiten in Beton‐ und Putzoberflächen visuell mit Hilfe von Risslinealen und Risslupen bestimmt. Diese subjektiven Messmethoden weisen eine geringe Genauigkeit auf und sind auf Grund fehlender Dokumentation und Nachvollziehbarkeit nur in wenigen Fällen zweckmäßig. Durch den Einsatz digitaler Methoden in der in‐situ‐Rissanalyse können die Messgenauigkeit deutlich erhöht und das Beobachtungsergebnis objektiv dokumentiert werden. In diesem Beitrag werden experimentelle und theoretische Untersuchungen der digitalen Rissanalyse von Betonoberflächen vorgestellt, die aber auch auf andere Baustoffe und Oberflächen angewendet werden können. Da bereits mit handelsüblichen Digitalkameras qualitativ hochwertige Ergebnisse erzielt werden, sind die hier vorgestellten Verfahren für baupraktische Fälle einsetzbar. Der folgende Beitrag zeigt die grundsätzliche Anwendungsmöglichkeit, hinsichtlich mathematischer Details wird auf Sekundärliteratur verwiesen.
Social interaction patterns of geriatric home and community residents
Authors: Boczkowski Judith A. , Adams Henry E. , Golden Cheryl 
Published: June 2007

AbstractThirty elderly nursing home residents and ten community residing older adults were observed in group settings. Their behavior was assessed for dependent personal maintenance, independent personal maintenance, and appropriate and inappropriate behaviors. Responses by staff and peers to these behaviors were classified as positive, negative, or ignore. The frequency of occurrence of these behaviors as well as the relationship of resident to peer or staff behaviors were analyzed. Results indicate that community‐residing elders' behaviors differ from nursing home residents' in quantity rather than quality of interactions. There was a lower frequency of behaviors in the nursing home residents. Though older adults respond differentially to various behaviors of other nursing home residents, staff responses were consistent regardless of residents' behavior. These results suggest that geriatric home residents' behavior can be characterized as withdrawn rather than dependent.
Training community residential staff: Evaluation and follow‐up
Authors: Rosen Howard S. , Yerushalmi Cydney J. , Walker Jane C. 
Published: June 2007

AbstractThe purpose of this study was to evaluate the effect of a comprehensive residential direct‐care staff training program on staff knowledge, record keeping, habilitation delivery, and turnover. A 40‐hour training course was presented to 18 direct‐care staff employed in three community residential facilities (CRF), while 18 staff in three other CRFs were placed on a waiting list. Sixteen of 18 trained staff (89%) increased use of habilitation activities, averaging 35.44% programming after training. Only six (33%) of the staff on the waiting list increased programming. The effectiveness of training was assessed against the gains of developmentally disabled (DD) consumers. In the training group, 31 of 36 (86.11%) residents increased on‐task behavior while only 7 of 22 (31.6%) of the waiting list residents increased on‐task behavior. Training also yielded improved client program records and a 50% decrease in staff turnover. Follow‐up over 12 months showed behavior maintenance. Results suggest that training based on clear learner objectives, presented using behavioral procedures, and taught to the entire staff including managers improves staff performance and client benefit.
Characteristics of the mentally retarded adolescent offender and their implications for residential treatment design
Authors: Denkowski George C. , Denkowski Kathryn M. 
Published: June 2007

AbstractWhile numerous residential programs for mentally retarded adolescent offenders have been established throughout this country, no empirically‐based population characteristics have been compiled which are sufficient to guide their systematic design. This study assessed 65 such young offenders along various treatment‐relevant dimensions, and used the resultant data to portray an average, hypothetical youth. Based on that profile, a compatible habilitation model was derived. It was concluded that a basic point economy, augmented by timeout procedures and supported by a secure (locked) setting, seems to be a viable approach for initiating treatment with these youth. Thereafter, programming should continue in a nonsecure group home, and finally, on an outpatient basis, in the generic community service system.
A survey of state policies regarding the use of restrictive/aversive behavior modification procedures
Authors: Spreat Scott , Lipinski David P. 
Published: June 2007

AbstractA survey was conducted of the state policies regarding the use of restrictive/ aversive behavior modification procedures with mentally retarded persons. Policies varied substantially with respect to both scope and length; however, the overwhelming majority required that behavior modification programs be developed through the interdisciplinary planning process. No consistent pattern emerged with respect to the review and approval process for the use of aversive procedures. Approximately 75% of the states appear to permit the use of restraint as a treatment modality. Policies direct only minimal attention to the issue of training staff to implement aversive procedures. From the results of the survey, a model for the use of aversive procedures was developed and is presented.
Evaluating the quality of training delivered by direct‐care staff in a state mental retardation center
Authors: Realon Rodney E. , Wheeler Andrew J. , Spring Bonnie , Springer Michael 
Published: June 2007

AbstractThis study evaluated a center‐wide training system in a state‐operated mental retardation center. Staff performance was assessed under varying conditions with collateral measures collected on resident behavior. The quality of training delivered by direct‐care staff was measured following the completion of an inservice training program and when individual feedback and praise were available or a group contingency where feedback, praise, and money were available. Inservice training was not found to be sufficient to maintain staff training skills. Providing feedback and praise had mixed results in maintaining staff behavior. A group contingency using feedback, praise, and money was found to be immediately effective in improving and maintaining staff behavior. Collateral measures on student behavior were also provided that indicated that consistent, quality training by staff resulted in increased student skill acquisition. These results are discussed within the framework of conducting research in applied settings.
Arranging a residential environment for the developmentally disabled to generate and maintain verbal behavior
Authors: Redinger Robyn , Alger Kathleen , Thomas Don R. 
Published: June 2007

AbstractA specialized residential unit was assembled at a state residential facility for mentally retarded residents in order to provide services for individuals who lacked functional speech but who were capable of learning manual signs. Program development focused on four areas. First, a routine was designed to engage residents in functional training activities throughout the day. Second, opportunities to teach signed verbal behavior within all components of the routine were identified. Third, structured training sessions were developed to augment training within normal daily living activities. Fourth, multiple staff training strategies were initiated. Initial outcome data indicate that signing skills of both staff and residents improved.
Duration of negative practice and the reduction of leg pounding of a traumatically brain‐injured adult
Authors: Lewis Frank D. , Blackerby William F. , Ross Janet Rainwater , Guth Mark L. , Cronkey Ronald F. , White Melvin J. , Cook Tina 
Published: June 2007

AbstractThis study evaluated the relative efficacy of long (1 minute) and short (15 seconds) durations of negative practice for reducing self‐stimulatory leg pounding of a traumatically brain‐injured adult. In individual social skill training classes, long negative practice and short negative practice were administered concurrently in an alternating treatments design. Generalization of treatment effects outside of training sessions was assessed during the client's lunch period. The results revealed that both durations of negative practice were equally effective in reducing leg pounding during training sessions. However, the effects of training did not generalize to settings in which the practice contingency was not enforced. Pounding was more frequent and negative practice somewhat less effective during periods of high social stimulation.
Behavior treatment, behavior management, and behavior control: Needed distinctions
Authors: Gardner William I. , Cole Christine L. 
Published: June 2007

AbstractBehavioral procedures are used frequently with persons who present the dual handicapping conditons of mental retardation and chronic behavior difficulties. It is suggested that behavior management and behavior control procedures are used excessively and at the expense of active behavior treatment. It is recommended that behavior treatment staff be more discriminating in use of these classes of procedures, and that the major focus of behavioral programs be that of active treatment.
Assessing pharmacological and contingency management interventions with mentally retarded adolescents in a residential treatment program
Authors: Luiselli James K. , Evans Tracy P. 
Published: June 2007

AbstractTwo studies were performed using applied behavior analytic methodology to evaluate pharmacological and contingency management interventions with mentally retarded adolescents in a residential treatment facility. In the first study, stimulant (methylphenidate) and beta‐blocking (propranolol) medications were compared with an overcorrection procedure to manage the disruptive vocalizing of a 14‐year‐old female. In the second study. the effects of thioridazine and a reinforcement‐response interruption program on stereotypic body‐rocking of an 18‐year‐old male were assessed. Both studies failed to demonstrate a positive response from any of the prescribed medications. Substantial reductions in behavior did occur with application of the contingency management programs. The programs were equally effective whether utilized alone or in combination with medication. Assessment and programmatic issues in the area of clinical behavioral pharmacology are discussed.