bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accuracy of the 15‐item geriatric depression scale (GDS‐15) in a community sample of the oldest old
Authors: de Craen Anton J. M. , Heeren T. J. , Gussekloo Jacobijn 
Published: December 2002

AbstractBackgroundCognitive impairment is common in the oldest old. This might influence the sensitivity and specificity of the 15‐item Geriatric Depression Scale (GDS‐15). Few studies, however, have included subjects older than 85 years to evaluate the GDS‐15 as a screening instrument for depression.ObjectiveTo assess the sensitivity and specificity of the GDS‐15 in a community sample of the oldest old.MethodsSeventy‐nine subjects aged 85 and over were enrolled in the study. The GDS‐15 and the Mini‐Mental State Examination (MMSE) were administered by a trained interviewer. Within two days the Geriatric Mental State (GMS)/AGECAT, was administered to obtain a clinical diagnosis of depression.ResultsEight subjects (10%) were diagnosed with clinical depression. At a cut‐off point of 3/4 the sensitivity and specificity of the GDS‐15 were 88% and 76% respectively. In the group with MMSE scores of 28 and higher sensitivity was unaffected at all cut‐off points while specificity increased. In the group with MMSE scores below 28 sensitivity was also unaffected at all cut‐off points while specificity decreased.ConclusionThe GDS‐15 is a suitable instrument to diagnose depression in the general population of the oldest old. The optimal cut‐off point depends on its intended use. In subjects with cognitive impairment the accuracy should be investigated further. Copyright © 2002 John Wiley & Sons, Ltd.
The concept of effective length in hillslopes: assessing the influence of climate and topography on the contributing areas of catchments
Authors: Aryal Santosh K. , Mein Russell G. , O'Loughlin Emmett M. 
Published: December 2002

AbstractThis paper introduces a concept of ‘effective length’ in hillslopes to define the effective area influencing the runoff‐producing saturated zones of a hillslope or catchment. This effective area of a catchment usually is less than that given by its physical boundaries, particularly in regions where the total potential evaporation exceeds total rainfall on an annual basis. In this paper, expressions for effective lengths in hillslopes with different scale, shape and soil properties are derived for given climatic conditions. The influence of these variables on effective length is investigated. It is shown that, for a given rainfall frequency and soil parameters, the effective length changes with the planform geometry and profile shape of a hillslope; it is also a function of the ratio of available travel opportunity time to the hillslope's scale response time. The application of the concept to three natural catchments, subdivided into a number of simple hillslopes, is described. It is shown that, for these three test catchments and over 24 years of record, rarely would the entire catchment areas contribute to flow at the respective outlets. The implications of the concept of effective length for several land‐use practices, such as clearing for forest for greater water yield, and planting trees for salinity control, are discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Surface glaciochemistry of Taylor Valley, southern Victoria Land, Antarctica and its relationship to stream chemistry
Authors: Berry Lyons W. , Welch Kathleen A. , Fountain Andrew G. , Dana Gayle L. , Vaughn Bruce H. , McKnight Diane M. 
Published: December 2002

AbstractWe have analysed a series of surface samples from the alpine glaciers of Taylor Valley, Southern Victoria Land, Antarctica for their geochemical composition. This was done to better establish the role of glaciochemical variation on the chemical composition of meltwater streams emanating from the glaciers. The chemistry of the snow and ice changes with proximity to the ocean and with elevation of the glacier surface. The aeolian transport of dry valley dust, as indicated by both chemical and particulate matter variations, is a major process affecting the overall glacier chemistry and the chemistry of the meltwaters. Streams originating on the western edges of the glaciers are more impacted by the aeolian input as they are in the direct path of the major regional wind direction. Our data strongly suggest that the variation in stream geochemistry in Taylor Valley is a result in part of the differences in chemical composition of glacier melt. Copyright © 2003 John Wiley & Sons, Ltd.
Separation of quantum and classical behavior in proton transfer reactions: Implications from studies of secondary kinetic isotope effects
Authors: Iftimie Radu , Schofield Jeremy 
Published: December 2002

AbstractIn this article the separability of the nuclear degrees of freedom system into mixed quantum and classical components is examined by looking at secondary kinetic isotope effects in a model proton transfer reaction. To explore this issue, the nature of secondary kinetic isotope effects is investigated by means of molecular mechanics and ab initio simulations of a model system in which intramolecular proton transfer occurs in a region whose chemical topology is similar to that of malonaldehyde. Isotope effects are calculated using importance sampling Monte Carlo techniques designed to improve the statistical efficiency of ab initio simulations within the framework of quantum centroid transition state theory. The ab initio results for kinetic isotope effects are contrasted with those obtained using two molecular mechanics potential energy functions. It is demonstrated that the calculated isotope effects are extremely sensitive to subtle features of the potential energy surface, which suggests that information from ab initio structure and energy calculations about configurations along the reaction path must be utilized in the construction of classical potentials to obtain accurate secondary kinetic isotope effect predictions. It is also demonstrated that quantum nuclear degrees of freedom of all secondary atoms that move significantly as a chemical reaction proceeds should be treated explicitly, as even secondary heavy‐atom tunneling effects could be significant. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Conformational study of the vinylphosphonic acid and derivatives
Authors: Omar Salama , Gonzalez‐Jonte Raúl , de la Vega José Manuel Garciá 
Published: December 2002

AbstractThe alkenyl phosphonics have become interesting compounds for the chemical industry. They have been used as drugs, polymer additives, flame retards, and metal extractants. The electronic structure of the smallest derivatives of this series of compounds, namely, vinylphosphonic acid (VPA), vinylphosphine oxide (VPO), and vinylphosphoryl dichloride (VPDC), are studied here. The nature of the phosphoryl bond was a subject of discussion because its electronic nature could be considered either as a resonance between a double bond and a single polarized bond or as a triple bond with different electronic possibilities. The electronic structure of VPA, VPO, and VPDC have been studied by density functional theory methods using a large basis set. Conformers “s‐cis,” “s‐cis‐gauche,” “s‐trans,” and “s‐trans‐gauche” and rotational barriers are determined for the internal rotational around the CP bond. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Generalized spin density functional study of radical reactions
Authors: Yamanaka S. , Ohsaku T. , Yamaki D. , Yamaguchi K. 
Published: December 2002

AbstractThe generalized spin orbital (GSO) density functional theory (DFT) is applied to the radical reaction involving spin inversion. Along the ground‐state path for the cleavage of oxygen molecule, GSO–DFT solutions simulate the intercrossing change from triplet oxygen molecule to two triplet oxygen atoms through helical spin density wave, indicating the importance of GSO treatment of DFT. Numerical results are discussed in relation to the relativistic effects of the realistic oxidation reaction of other species, together with the near‐degeneracy effects discussed in relation to the multireference DFT. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
DFT study of ionization potentials for aza‐substituted aromatic rings
Authors: Barrio Laura , Catalán Javier , de Paz José L. G. 
Published: December 2002

AbstractThe ionization potentials of 20 azines and azanaphthalenes have been studied using Becke's three‐parameter exchange functional and the gradient‐corrected functional of Lee, Yang, and Paar (B3LYP) method with 6‐31G** basis set at optimized geometries. Vertical ionization potentials (IPV) have been calculated using Koopman's theorem (IPV = −εHOMO) and as the difference of single‐point energy calculations for the corresponding cation and for the neutral form (IPV = Ecation − Eneutral). From our theoretical results most of the first ionizations come from the nitrogen lone pair and not from the highest occupied π‐orbital. Good agreement is found with experimental results when IPV is calculated from unrestricted B3LYP calculations of the neutral and the cationic species. The first π‐ionization follows Koopman's theorem for all monocyclic and bi‐cyclic systems under study. The lone pair repulsion effect is acceptably described by the energy of the highest n‐orbital energy either for azines and azanaphthalenes. The annulation effect in the charged species is not reflected in the n–lone pair orbital energy of the neutral form and, consequently, it is not possible to find a fit that follows Koopman's theorem for lone pair orbital energies. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
DFT calculations of correlation energies for excited electronic states using MCSCF wave functions
Authors: San‐Fabián E. , Pastor‐Abia L. 
Published: December 2002

AbstractA large set of correlation energy functionals has been applied, in a post‐SCF procedure, to incorporate the correlation energy of several excited atomic states using MCSCF wave functions. The results show that the application of standard density functionals does not consider the double count of the correlation energy obtained by the MCSCF wave function. However, the use of some dependence on the two‐body density matrix improves the results, with a partial account of this correlation energy balance. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Ab initio study on elementary radical reactions in coke formation
Authors: Van Speybroeck V. , Van Neck D. , Waroquier M. , Wauters S. , Saeys M. , Marin G. B. 
Published: December 2002

AbstractAb initio calculations are presented on radical reactions that occur during the formation of coke in a thermal cracking unit. Kinetic parameters for the addition reaction of the ethylbenzene radical to ethene and the subsequent cyclization of the butylbenzene radical are calculated by means of Transition State Theory and Density Functional Theory. Special care is taken to correctly treat the internal rotations to predict accurate values of the preexponential factor. The influence of the local structure of the coke matrix on the kinetic parameters is tested by calculating kinetic parameters of clusters consisting of more than one benzene ring. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
An LMI approach to guaranteed cost control for uncertain linear neutral delay systems
Authors: Xu Shengyuan , Lam James , Yang Chengwu , Verriest Erik I. 
Published: December 2002

AbstractThis paper considers the problem of guaranteed cost control for uncertain neutral delay systems with a quadratic cost function. The system under consideration is subject to norm‐bounded time‐varying parametric uncertainty appearing in all the matrices of the state‐space model. The problem we address is the design of a state feedback controller such that the closed‐loop system is not only stable but also guarantees an adequate level of performance for all admissible uncertainties. A sufficient condition for the existence of guaranteed cost controllers is given in terms of a linear matrix inequality (LMI). When this condition is feasible, the desired state feedback controller gain matrices can be obtained via convex optimization. An illustrative example is provided to demonstrate the effectiveness of the proposed approach. Copyright © 2002 John Wiley & Sons, Ltd.
Mapping Residents' Perceptions of Neighborhood Boundaries: A Methodological Note
Authors: Coulton Claudia J. , Korbin Jill , Chan Tsui , Su Marilyn 
Published: December 2002

AbstractNeighborhood influences on children and youth are the subjects of increasing numbers of studies, but there is concern that these investigations may be biased, because they typically rely on census‐based units as proxies for neighborhoods. This pilot study tested several methods of defining neighborhood units based on maps drawn by residents, and compared the results with census definitions of neighborhoods. When residents' maps were used to create neighborhood boundary definitions, the resulting units covered different space and produced different social indicator values than did census‐defined units. Residents' agreement about their neighborhoods' boundaries differed among the neighborhoods studied. This pilot study suggests that discrepancies between researcher and resident‐defined neighborhoods are a possible source of bias in studies of neighborhood effects.
Inhibition of substrate synthesis as a strategy for glycolipid lysosomal storage disease therapy
Authors: Platt F. M. , Jeyakumar M. , Andersson U. , Priestman D. A. , Dwek R. A. , Butters T. D. , Cox T. M. , Lachmann R. H. , Hollak C. , Aerts J. M. F. G. , Van Weely S. , Hrebícek M. , Moyses C. , Gow I. , Elstein D. , Zimran A. 
Published: December 2002

AbstractThe glycosphingolipid (GSL) lysosomal storage diseases are caused by mutations in the genes encoding the glycohydrolases that catabolize GSLs within lysosomes. In these diseases the substrate for the defective enzyme accumulates in the lysosome and the stored GSL leads to cellular dysfunction and disease. The diseases frequently have a progressive neurodegenerative course. The therapeutic options for treating these diseases are relatively limited, and for the majority there are no effective therapies. The problem is further compounded by difficulties in delivering therapeutic agents to the brain. Most research effort to date has focused on strategies for augmenting enzyme levels to compensate for the underlying defect. These include bone marrow transplantation (BMT), enzyme replacement and gene therapy. An alternative strategy that we have been exploring is substrate deprivation. This approach aims to balance the rate of GSL synthesis with the impaired rate of GSL breakdown. The imino sugar N‐butyldeoxynojirimycin (NB‐DNJ) inhibits the first step in GSL biosynthesis and has been used to evaluate this approach. Studies in an asymptomatic mouse model of Tay–Sachs disease have shown that substrate deprivation prevents GSL storage in the CNS. In a severe neurodegenerative mouse model of Sandhoff disease, substrate deprivation delayed the onset of symptoms and disease progression and significantly increased life expectancy. Combining NB‐DNJ and BMT was found to be synergistic in the Sandhoff mouse model. A clinical trial in type I Gaucher disease has been undertaken and has shown beneficial effects. Efficacy was demonstrated on the basis of significant decreases in liver and spleen volumes, gradual but significant improvement in haematological parameters and disease activity markers, together with diminished GSL biosynthesis and storage as determined by independent biochemical assays. Further trials in type I Gaucher disease are in progress; studies are planned in patients with GSL storage in the CNS.
Building Collaborative Capacity in Community Coalitions: A Review and Integrative Framework
Authors: Foster-Fishman Pennie G. , Berkowitz Shelby L. , Lounsbury David W. , Jacobson Stephanie , Allen Nicole A. 
Published: December 2002

AbstractThis article presents the results of a qualitative analysis of 80 articles, chapters, and practitioners' guides focused on collaboration and coalition functioning. The purpose of this review was to develop an integrative framework that captures the core competencies and processes needed within collaborative bodies to facilitate their success. The resulting framework for building collaborative capacity is presented. Four critical levels of collaborative capacity—member capacity, relational capacity, organizational capacity, and programmatic capacity—are described and strategies for building each type are provided. The implications of this model for practitioners and scholars are discussed.
Enzyme therapy for Pompe disease with recombinant human α‐glucosidase from rabbit milk
Authors: Van den Hout J. M. P. , Reuser A. J. J. , de Klerk J. B. C. , Arts W. F. , Smeitink J. A. M. , Van der Ploeg A. T. 
Published: December 2002

AbstractPompe disease is a metabolic myopathy caused by deficiency of lysosomal acid α‐glucosidase. In this report we review the first 36 weeks of a clinical study on the safety and efficacy of enzyme therapy aimed at correcting the deficiency. Four patients with infantile Pompe disease were enrolled. They received recombinant human α‐glucosidase from transgenic rabbit milk. The product is generally well tolerated and reaches the primary target tissues. Normalization of α‐glucosidase activity in skeletal muscle was obtained and degradation of PAS‐positive material was seen in tissue sections. The clinical condition of all patients improved. The effect on heart was most significant, with an impressive reduction of the left ventricular mass index (LVMI). Motor function improved. The positive preliminary results stimulate continuation and extension of efforts towards the realization of enzyme therapy for Pompe disease.
Rare diseases and the assessment of intervention: What sorts of clinical trials can we use?
Authors: Wilcken B. 
Published: December 2002

AbstractThere is increasing emphasis on the importance of practising evidence‐based medicine. Randomized controlled trials are the standard way to assess the benefits of an intervention, and observational studies are not usually accorded much weight; the results are likely to be considered misleading. For rare diseases, there are great difficulties in obtaining adequate evidence for interventions or for the benefits of early diagnosis. This is because the disorders are not only very rare but also have variable expression, may have very long courses, and have incompletely known late effects; and surrogate end‐points often have to be used. Randomized controlled trials are usually impossible because of inadequate power, and because there are preconceived notions of the effects of treatments already in use. The adoption of the best possible design for observational trials, formation of a central registry of such trials, and a greater general appreciation of the problems that rare diseases pose will help in obtaining the best possible evidence for the effects of interventions.
Value‐Based Praxis in Community Psychology: Moving Toward Social Justice and Social Action
Authors: Prilleltensky Isaac 
Published: December 2002

AbstractThe purpose of this paper is to articulate a rationale for value‐based praxis in community psychology. Although values need to promote personal, collective, and relational wellness at the same time, it is argued that community psychologists pay more attention to personal and relational wellness than to collective wellness. In order to address this imbalance it is important to promote the value of social justice. While praxis requires that we engage in a cycle of reflection, research, and social action, community psychologists devote more resources to the first two phases of praxis than to the last one. This paper offers a framework for deciding what values and what praxis considerations we should attend to and how we may advance social justice and social action in community psychology.
Innovation in HIV Prevention: Organizational and Intervention Characteristics Affecting Program Adoption
Authors: Miller Robin Lin 
Published: December 2002

AbstractA multiple case study design was used to explore the organizational characteristics of community‐based organizations that provide HIV prevention programs and the criteria these organizations employ when judging the merits of externally‐developed HIV prevention programs. In‐depth interviews were conducted with organizational representatives of 38 randomly‐selected HIV prevention providers throughout Illinois. Results indicated that there were three main types of adopting organizations: adopters of entire programs, adopters of program components and practices, and adopters of common ideas. These three types of organizations were distinguished by their level of organizational commitment to HIV prevention, organizational resources, and level of organizational maturity. Narrative data from the interviews are used to describe the dimensions that underlie the organizations' program adoption criteria. The criteria of merit used by these organizations to evaluate prevention programs provide partial empirical support for existing theories of technology transfer. Implications for designing and disseminating HIV prevention programs are discussed.
Membrane Fusion
Authors: Epand Richard M. 
Published: December 2002

The fusion of biological membranes results in two bilayer-based membranes merging into a single membrane. In this process the lipids have to undergo considerable rearrangement. The nature of the intermediates that are formed during this rearrangement has been investigated. Certain fusion proteins facilitate this process. In many cases short segments of these fusion proteins have a particularly important role in accelerating the fusion process. Studies of the interaction of model peptides with membranes have allowed for increased understanding at the molecular level of the mechanism of the promotion of membrane fusion by fusion proteins. There is an increased appreciation of the roles of several independent segments of fusion proteins in promoting the fusion process.
Many of the studies of the fusion of biological membranes have been done with the fusion of enveloped viruses with other membranes. One reason for this is that the number of proteins involved in viral fusion is relatively simple, often requiring only a single protein. For many enveloped viruses, the structure of their fusion proteins has certain common elements, suggesting that they all promote fusion by an analogous mechanism. Some aspects of this mechanism also appears to be common to intracellular fusion, although several proteins are involved in that process which is more complex and regulated than is fusion.
Carrier detection and rapid newborn diagnostic test for the common Y393N maple syrup urine disease allele by PCR‐RFLP: Culturally permissible testing in the Mennonite community
Authors: Love‐Gregory L. D. , Dyer J. A. , Grasela J. , Hillman R. E. , Phillips C. L. 
Published: December 2002

AbstractThe turnaround time for diagnosis of maple syrup urine disease (MSUD) by classic serum amino acid analyses often requires 3–4 days. This is due to the need for branched‐chain amino acids (BCAA) to accumulate in the serum of the newborn before testing. The accumulation of BCAAs in infants with MSUD during this time increases the risk of the infant becoming clinically symptomatic. We have developed a noninvasive DNA‐based mismatch PCR‐RFLP assay for the Y393N BCKDHA allele (E1α gene of the branched chain α‐keto acid dehydrogenase complex), the primary cause of MSUD in Old Order Mennonite communities. The homozygosity and high frequency of this mutation in the Mennonite community and its prevalence in compound heterozygote non‐Mennonite MSUD patients is of significance. We describe carrier testing, present the results of nine newborns diagnostically evaluated for the Y393N BCKDHA allele, and demonstrate the efficacy of this PCR‐RFLP assay for determining clinical status within 24 h after birth. Analyses within the first 24h of life allow for immediate diagnosis and treatment of infants homozygous for the Y393N MSUD defect. This is a significant improvement over the time required by current serum amino acid analysis methods.