bluuebunny/crossref_metadata_2025 huggingface dataset:
Ribonucleoprotein-dependent localization of the yeast class V myosin Myo4p
Authors: Kruse Claudia , Jaedicke Andreas , Beaudouin Joël , Böhl Florian , Ferring Dunja , Güttler Thomas , Ellenberg Jan , Jansen Ralf-Peter
Published: December 2002

Class V myosins are motor proteins with functions in vesicle transport, organelle segregation, and RNA localization. Although they have been extensively studied, only little is known about the regulation of their spatial distribution. Here we demonstrate that a GFP fusion protein of the budding yeast class V myosin Myo4p accumulates at the bud cortex and is a component of highly dynamic cortical particles. Bud-specific enrichment depends on Myo4p's association with its cargo, a ribonucleoprotein complex containing the RNA-binding protein She2p. Cortical accumulation of Myo4p at the bud tip can be explained by a transient retention mechanism that requires SHE2 and, apparently, localized mRNAs bound to She2p. A mutant She2 protein that is unable to recognize its cognate target mRNA, ASH1, fails to localize Myo4p. Mutant She2p accumulates inside the nucleus, indicating that She2p shuttles between the nucleus and cytoplasm and is exported in an RNA-dependent manner. Consistently, inhibition of nuclear mRNA export results in nuclear accumulation of She2p and cytoplasmic Myo4p mislocalization. Loss of She2p can be complemented by direct targeting of a heterologous lacZ mRNA to a complex of Myo4p and its associated adaptor She3p, suggesting that She2p's function in Myo4p targeting is to link an mRNA to the motor complex.
The prepower stroke conformation of myosin V
Authors: Burgess Stan , Walker Matt , Wang Fei , Sellers James R. , White Howard D. , Knight Peter J. , Trinick John
Published: December 2002

eW have used electron microscopy and single-particle image processing to study head conformation in myosin V molecules. We find that in the presence of ATP, many heads have a sharply angled conformation that is rare in its absence. The sharply angled conformation is similar to a myosin II atomic structure proposed to mimic the prepower stroke state. The leading head in molecules attached to actin by both heads has a similar conformation, but is also sharply angled in a second plane by tethering through the trail head. The lead head lever joins the motor domain ∼5 nm axially from where it joins the trail motor. These positions locate the converter subdomain and show the lead motor is in the prepower stroke conformation. Tethering by the trail head places the lead head motor domain at the correct axial position along the actin for binding, but at the wrong orientation. Attachment is achieved either by bending the lead head lever throughout its length or at the pliant point. The microscopy shows that most of the walking stride is produced by changes in lever angle brought about by converter movement, but is augmented by distortion produced by thermal energy.
Migration of nerve growth cones requires detergent-resistant membranes in a spatially defined and substrate-dependent manner
Authors: Nakai Yoko , Kamiguchi Hiroyuki
Published: December 2002

Motility of nerve growth cones (GCs) is regulated by region-specific activities of cell adhesion molecules (CAMs). CAM activities could be modified by their localization to detergent-resistant membranes (DRMs), specialized microdomains enriched in signaling molecules. This paper deals with a question of whether DRMs are involved in GC migration stimulated by three CAMs; L1, N-cadherin (Ncad), and β1 integrin. We demonstrate that L1 and Ncad are present in DRMs, whereas β1 integrin is exclusively detected in non-DRMs of neurons and that localization of L1 and Ncad to DRMs is developmentally regulated. GC migration mediated by L1 and Ncad but not by β1 integrin is inhibited after DRM disruption by micro-scale chromophore-assisted laser inactivation (micro-CALI) of GM1 gangliosides or by pharmacological treatments that deplete cellular cholesterol or sphingolipids, essential components for DRMs. Characteristic morphology of GCs induced by L1 and Ncad is also affected by micro-CALI–mediated DRM disruption. Micro-CALI within the peripheral domain of GCs, or even within smaller areas such as the filopodia and the lamellipodia, is sufficient to impair their migration. However, micro-CALI within the central domain does not affect GC migration. These results demonstrate the region-specific involvement of DRMs in CAM-dependent GC behavior.
An extensible application for assembling annotation for
genomic data
Authors: Zhang Jianhua , Carey Vincent , Gentleman Robert
Published: December 2002

Summary: AnnBuilder is an R package for assembling genomic annotation data. The system currently provides parsers to process annotation data from LocusLink, Gene Ontology Consortium, and Human Gene Project and can be extended to new data sources via user defined parsers. AnnBuilder differs from other existing systems in that it provides users with unlimited ability to assemble data from user selected sources. The products of AnnBuilder are files in XML format that can be easily used by different systems.

Availability: (http://www.bioconductor.org). Open source.

Contact: jzhang@jimmy.harvard.edu

* To whom correspondence should be addressed.
Detection of hydrogen-bond signature patterns in protein families
Authors: Prasad Tejasvini , Prathima M. N. , Chandra Nagasuma
Published: December 2002

Summary: We have developed a WWW server, HBPRINT, for the identification of hydrogen–bond signature patterns in protein families from their structures. The server calculates (a) common hydrogen bonds between two structures (b) a hydrogen-bond fingerprint in a set of structural neighbours and (c) details of conserved hydrogen bonds. The server also enables the visualization of the hydrogen bond network comprising the signature pattern.

Availability: HBPRINT and a tutorial are available from http://144.16.93.115/hb_page/index.html

Contact: nchandra@physics.iisc.ernet.in

* To whom correspondence should be addressed.
Wavelets in bioinformatics and computational biology:
state of art and perspectives
Authors: Liò Pietro
Published: December 2002

Motivation: At a recent meeting†, the wavelet transform was depicted as a small child kicking back at its father, the Fourier transform. Wavelets are more efficient and faster than Fourier methods in capturing the essence of data. Nowadays there is a growing interest in using wavelets in the analysis of biological sequences and molecular biology-related signals.

Results: This review is intended to summarize the potential of state of the art wavelets, and in particular wavelet statistical methodology, in different areas of molecular biology: genome sequence, protein structure and microarray data analysis. I conclude by discussing the use of wavelets in modeling biological structures.

Contact: plio@hgmp.mrc.ac.uk

† XIX SMC 2001 ‘Wavelets in Statistics’, Vico Equense, Naples, I, 2–7 April 2001.
Simple rules underlying gene expression profiles
of more than six subtypes of acute lymphoblastic leukemia (ALL)
patients
Authors: Li Jinyan , Liu Huiqing , Downing James R. , Yeoh Allen Eng-Juh , Wong Limsoon
Published: December 2002

Motivations and Results: For classifying gene expression profiles or other types of medical data, simple rules are preferable to non-linear distance or kernel functions. This is because rules may help us understand more about the application in addition to performing an accurate classification. In this paper, we discover novel rules that describe the gene expression profiles of more than six subtypes of acute lymphoblastic leukemia (ALL) patients. We also introduce a new classifier, named PCL, to make effective use of the rules. PCL is accurate and can handle multiple parallel classifications. We evaluate this method by classifying 327 heterogeneous ALL samples. Our test error rate is competitive to that of support vector machines, and it is 71% better than C4.5, 50% better than Naive Bayes, and 43% better than k-nearest neighbour. Experimental results on another independent data sets are also presented to show the strength of our method.

Availability: Under http://sdmc.lit.org.sg/GEDatasets/, click on Supplementary Information.

Contact: jinyan@lit.a-star.edu.sg

* To whom correspondence should be addressed.
pfcrt
Polymorphism and Chloroquine Resistance in
Plasmodium falciparum
Strains Isolated in Cambodia
Authors: Lim Pharath , Chy Sophy , Ariey Frédéric , Incardona Sandra , Chim Pektra , Sem Rithy , Denis Mey Bouth , Hewitt Sean , Hoyer Stefan , Socheat Doung , Merecreau-Puijalon Odile , Fandeur Thierry
Published: December 2002

Plasmodium falciparum
chloroquine resistance was first detected in Cambodia in the early sixties. Treatment with chloroquine was abandoned 20 years ago. In vitro chloroquine sensitivity monitoring indicates that all eastern Cambodian isolates were sensitive to chloroquine, whereas most isolates collected from western provinces displayed reduced susceptibility to chloroquine. This indicates that the rate of chloroquine resistance remains high and stable in this region in the absence of chloroquine pressure. Characterization of codons 72 to 78 and 218 to 220 of
pfcrt
revealed six distinct haplotypes, four of which had never been described. The frequency of each haplotype depended on the geographical origin of the samples. The CVIETIF//ISS haplotype was detected in 92% of western Cambodian isolates and in 11% of isolates collected from the eastern province, where CVMNKIF//ISA and CVIDTIF//ISS predominate. The detection of an intermediate haplotype from a susceptible area with 76T/220A, suggests that acquisition of chloroquine resistance might be a stepwise process, during which accumulation of point mutations modulates the response to chloroquine. The association of the K76T mutation with chloroquine resistance was not clear. The mutation was detected in resistant and susceptible samples, suggesting that additional factors are involved in chloroquine resistance. By contrast, the
pfcrt
D/N75E mutation was strongly associated with the in vitro chloroquine resistance in Cambodian isolates. The N86 allelic form of
pfmdr1
was detected in all isolates, consistent with a poor association with resistance to chloroquine. This indicates that in vitro resistance to chloroquine was associated with accumulation of point mutations in
pfcrt
.
Psychological Aspects of Natural Language Use: Our Words, Our Selves
Authors: Pennebaker James W. , Mehl Matthias R. , Niederhoffer Kate G.
Published: December 2002

The words people use in their daily lives can reveal important aspects of their social and psychological worlds. With advances in computer technology, text analysis allows researchers to reliably and quickly assess features of what people say as well as subtleties in their linguistic styles. Following a brief review of several text analysis programs, we summarize some of the evidence that links natural word use to personality, social and situational fluctuations, and psychological interventions. Of particular interest are findings that point to the psychological value of studying particles—parts of speech that include pronouns, articles, prepositions, conjunctives, and auxiliary verbs. Particles, which serve as the glue that holds nouns and regular verbs together, can serve as markers of emotional state, social identity, and cognitive styles.
Interdependence, Interaction, and Relationships
Authors: Rusbult Caryl E. , Van Lange Paul A. M.
Published: December 2002

Interdependence theory presents a logical analysis of the structure of interpersonal situations, offering a conceptual framework in which interdependence situations can be analyzed in terms of six dimensions. Specific situations present specific problems and opportunities, logically implying the relevance of specific motives and permitting their expression. Via the concept of transformation, the theory explains how interaction is shaped by broader considerations such as long-term goals and concern for a partner's welfare. The theory illuminates our understanding of social-cognitive processes that are of longstanding interest to psychologists such as cognition and affect, attribution, and self-presentation. The theory also explains adaptation to repeatedly encountered interdependence patterns, as well as the embodiment of such adaptations in interpersonal dispositions, relationship-specific motives, and social norms.
Psychotherapy for Children and Adolescents
Authors: Kazdin Alan E.
Published: December 2002

Child and adolescent therapy has progressed considerably, as reflected in the number of controlled studies, their methodological quality, and identification of evidence-based treatments. Treatments with strong evidence in their behalf are used for several clinical problems. Despite the progress, several key areas have been neglected in research and this has greatly limited what we know about treatment. Prominent among these areas of neglect is research on the mechanisms of change, the moderators of treatment outcome, and the generality of research findings to the conditions of clinical practice. This article highlights progress, characteristics, and limitations of current therapy research. In addition, a research plan is offered to advance research by (a) understanding the mechanisms or processes through which therapeutic change occurs, (b) drawing on developmental psychopathology research to inform treatment, (c) expanding the range of questions that guide treatment research and the range of outcome domains on which treatment conclusions are based, and (d) monitoring progress to ensure that critical questions about treatment are addressed.
Operant Conditioning
Authors: Staddon J. E. R. , Cerutti D. T.
Published: December 2002

Operant behavior is behavior “controlled” by its consequences. In practice, operant conditioning is the study of reversible behavior maintained by reinforcement schedules. We review empirical studies and theoretical approaches to two large classes of operant behavior: interval timing and choice. We discuss cognitive versus behavioral approaches to timing, the “gap” experiment and its implications, proportional timing and Weber's law, temporal dynamics and linear waiting, and the problem of simple chain-interval schedules. We review the long history of research on operant choice: the matching law, its extensions and problems, concurrent chain schedules, and self-control. We point out how linear waiting may be involved in timing, choice, and reinforcement schedules generally. There are prospects for a unified approach to all these areas.
Implicit Measures in Social Cognition Research: Their Meaning and Use
Authors: Fazio Russell H. , Olson Michael A.
Published: December 2002

Behavioral scientists have long sought measures of important psychological constructs that avoid response biases and other problems associated with direct reports. Recently, a large number of such indirect, or “implicit,” measures have emerged. We review research that has utilized these measures across several domains, including attitudes, self-esteem, and stereotypes, and discuss their predictive validity, their interrelations, and the mechanisms presumably underlying their operation. Special attention is devoted to various priming measures and the Implicit Association Test, largely due to their prevalence in the literature. We also attempt to clarify several unresolved theoretical and empirical issues concerning implicit measures, including the nature of the underlying constructs they purport to measure, the conditions under which they are most likely to relate to explicit measures, the kinds of behavior each measure is likely to predict, their sensitivity to context, and the construct's potential for change.
Transient scattering of SH waves from an inclusion with a unilateral frictional interface—a 2D time domain boundary element analysis
Authors: Feng Yang‐De , Wang Yue‐Sheng , Zhang Zi‐Mao
Published: December 2002

This paper develops a 2D time domain boundary element method (BEM) to solve the transient SH‐wave scattering from an inclusion with a unilateral frictional interface. The incident SH‐wave is assumed strong enough to break friction so that localized slip takes place along the interface. The present problem is indeed a non‐linear boundary value problem since the mixed boundary conditions involve unknown intervals (the slip and stick zones). In order to determine the intervals, an iterative technique is developed. As an example, we consider the scattering of a circular cylinder embedded in an infinite solid. The numerical results of the interface traction and relative slip velocity are presented. Copyright © 2003 John Wiley & Sons, Ltd.
Numerical performance of preconditioning techniques for the solution of complex sparse linear systems
Authors: Mazzia Annamaria , Pini Giorgio
Published: December 2002

Preconditioning techniques based on ILU decomposition, on Frobenius norm minimization and on factorized sparse approximate inverse are considered. These algorithms are applied with conjugate gradient‐type methods, namely Bi‐CGSTAB, QMR and TFQMR for the solution of complex, large, sparse linear systems. The results of numerical experiments in scalar environment with matrices arising from transport in porous media, quantum chemistry, structural dynamics and electromagnetism are analysed. The preconditioner that appears most significant in parallel environment (based on factorized sparse approximate inverse) is then employed on a Cray T3E supercomputer. The experimental results show the satisfactory parallel performance of the proposed algorithm. Copyright © 2003 John Wiley & Sons, Ltd.
A convergent and universally bounded interpolation scheme for the treatment of advection
Authors: Alves M. A. , Oliveira P. J. , Pinho F. T.
Published: December 2002

A high resolution scheme with improved iterative convergence properties was devised by incorporating total‐variation diminishing constraints, appropriate for unsteady problems, into an implicit time‐marching method used for steady flow problems. The new scheme, referred to as Convergent and Universally Bounded Interpolation Scheme for the Treatment of Advection (CUBISTA), has similar accuracy to the well‐known SMART scheme, both being formally third‐order accurate on uniform meshes for smooth flows. Three demonstration problems are considered: (1) advection of three scalar profiles, a step, a sine‐squared, and a semi‐ellipse; (2) Newtonian flow over a backward‐facing step; and (3) viscoelastic flow through a planar contraction and around a cylinder. For the case of the viscoelastic flows, in which the high resolution schemes are also used to represent the advective terms in the constitutive equation, it is shown that only the new scheme is able to provide a converged solution to the prescribed tolerance. Copyright © 2003 John Wiley & Sons, Ltd.
Uranium and thorium isotopes in the rivers of the Amazonian basin: hydrology and weathering processes
Authors: Marques Aguinaldo N. , Al‐Gharib Iyad , Bernat Michel , Fernex François
Published: December 2002

Two expeditions (October 1989 and May 1992) were carried out to two points of the main Amazon River channel and four tributaries. The Solimões and Madeira rivers, taking their origin in the Andes, are whitewater rivers. The Negro River is a typical acid, blackwater river. The Trombetas River flows through bauxite‐rich areas, and is characterized by low concentrations of dissolved humic substances. The 238U, 234U, 232Th and 230Th activities were recorded from dissolved, suspended particulate phases and river bank sediments. The latter were analysed for their 226Ra, 228Ra and 210Pb contents, and also subjected to leaching with 0·2 M hydroxylamine–hydrochloride solution to determine the concentrations of radionuclides bound to amorphous Fe hydroxides and Mn oxides and hydroxides.

The dissolved U average concentration in the Amazon system is ten times lower than the mean world river concentration. The uranium concentration observed at Óbidos in the lower Amazon (0·095 µg L−1), where the U content in the river bank sediments and suspended matter is lowest, suggests U release from the solid phase during river transport. About 485 t of U are transported annually to the Amazon delta area in dissolved form, and 1943 t bound to suspended particulate matter.

Total U and Th concentrations in the river bank sediments ranged from 1·59 to 7·14 µg g−1 and from 6·74 to 32 µg g−1, respectively. The highest concentrations were observed in the Trombetas River. The proportion extracted by means of the hydroxylamine solution (HL) was relatively high for U in the Trombetas river bank sediment (31%) and for Th in the Solimões sediment (30%).

According to the alpha recoil effects, the 234U/238U activity ratios of the Andean river waters and downstream Amazon water (Óbidos) were >1, but were <1 in the Negro River (at Manaus). The activity ratios of dissolved U correlate with pH and also with the U activity ratios in the river bank sediment hydroxylamine extracts. As expected, the 234U/238U activity ratios in river bank sediments were <1 in the Andean rivers and in the downstream Amazon, but they were >1 in the Trombetas and Negro rivers. Such ratios probably result from the binding of dissolved uranium to solid sediment.

The 228Th/232Th ratios of river bank sediments were close to unity (except for the Negro River, where it is lower), suggesting no significant Th exchanges between the river water and the sediment. The 226Ra/232Th activity ratios were <1, and the 226Ra/228Ra activity ratios generally were significantly higher than the activity ratios of their respective parents. This perhaps is the result of easier leaching of the 226Ra parent, 230Th, from solid material (owing to the alpha recoil effect) than of the 228Ra parent.

Uranium and thorium isotopes were used as tools to evaluate the chemical weathering rate of rocks in the Amazon system, which was estimated to be 2·7 cm 1000 year−1 s−1. Copyright © 2002 John Wiley & Sons, Ltd.
Slope–area relationships and sediment dynamics in two alpine streams
Authors: Fontana Giancarlo Dalla , Marchi Lorenzo
Published: December 2002

The paper focuses on the channel network of alpine basins, attempting to interpret channel reaches in terms of response to erosion and deposition processes. Two basins in the Dolomites (north‐eastern Italy) were considered: the Rio Cordon (5 km2) and the upper Boite River (163 km2). The channel network was extracted from raster‐type digital elevation models (DEM) using a slope–area threshold criterion. A contribution area index (CAI), which combines drainage area, A, and local slope, S (CAI = A0·5S), was used to identify channel heads. The channel network extracted from the DEM was then analysed to recognize cells showing a value of CAI lower than the threshold adopted for channel initiation. Contiguous cells with low values of CAI define channel reaches with low transport efficiency. Field surveys carried out for some selected cases showed a good agreement between prevailing sediment deposition predicted by the analysis of the channel network and observed channel morphological features. Sediment sources mapped in two study basins were also analysed in relation to the location of channels with high potential for sediment deposition: this made it possible to classify the potential role of different types of sediment sources with regard to basin sediment yield. Topographic characteristics of the channel network, expressed by CAI, were compared with a classification of channel morphology in the Rio Cordon. It was found that cells with low values of CAI frequently occur in the riffle–pool reaches, whereas the percentage significantly decreases in step–pool and bedrock channels. Copyright © 2003 John Wiley & Sons, Ltd.
Calculation of NMR chemical shifts for taxol and α‐pinene within the generalized gradient approximation
Authors: Bouř Petr
Published: December 2002

Simulations of the nuclear magnetic shielding within the generalized gradient approximation (GGA) for α‐pinene and taxol were carried out to assess the performance of the method for bigger molecules. The localized orbital/local origin gauge (LORG) formalism and the modified “0.05” Becke's three‐parameter exchange functional and the gradient‐corrected functional of Lee, Yang, and Paar (B3LYP) proposed recently by Wilson and others was used. A modest dependence of the results on the basis set size was observed. For the current implementation, the uncoupled calculations were up to 47 times faster than the usual coupled‐perturbed (CP)–gauge‐invariant atomic orbital (GIAO) method and provided similar accuracy. Reproducing both the absolute as the relative chemical shifts the GGA/LORG procedure can thus be used as a faster alternative to the coupled techniques. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Geometric and electronic structure of zwitterionic push–pull polyenes for nonlinear optics
Authors: Geskin V. M. , Bredas J. L.
Published: December 2002

We present a study of the chemical structure of highly polar push–pull conjugated molecules of interest for nonlinear optics, in which purely inductive ammonium/borate substituents, R3N+/BR, are attached to a trans‐polyene chain of variable length either directly or via phenyl groups. The performance of ab initio Hartree–Fock and Møller–Plesset second order (MP2) methods is compared with that of the hybrid density functional theory (DFT) and semiempirical (AM1) Hartree–Fock and configuration interaction methods. Taking into account electron correlation at the MP2 level is important to obtain reliable molecular geometries; the hybrid DFT (BH and HLYP functional) results are found to be in close agreement with the MP2 results. Some geometries obtained with the semiempirical methods are in qualitative disagreement with the MP2/6‐31G results. A chemical rationalization of the optimized structures and the nature of the substituent effect is proposed. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Density functional study of the redox processes in subphthalocyanines
Authors: Ferro V. R. , Poveda L. A. , Claessens C. G. , González‐Jonte R. H. , García de la Vega J. M.
Published: December 2002

A theoretical investigation on the redox processes in the subphthalocyanines (SubPcs) was performed. Singly and doubly oxidative and reductive transformations were considered. The full geometry optimization of the participating molecules showed that the cone shape arrangement of the SubPc is preserved in their ionic derivatives even when two electrons are either donated or subtracted from the molecule. The biggest geometric changes under electron exchange processes were calculated for the BCl bond distance. The electronic density distribution over all the products remains almost invariable with respect to the neutral molecule. Our calculations on the neutral and charged SubPcs demonstrated that they behave as conjugated systems, their electronic parameters being correlatively altered by the redox electron exchange. Further, the electronic state of the macrocycle atoms also depends on an intense electronic flow among the macrocyclic skeleton and the surrounding (axial chlorine and peripheral hydrogen) atoms that is associated with the redox process. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Theoretical studies of isomerization barriers of 2‐pentoxy radical and its products
Authors: Lin Ching‐Yeh , Ho Jia‐Jen
Published: December 2002

This article deals with the calculation of isomerization reaction of 2‐pentoxy radical via its possible processes to form the stable products by density functional theory. We studied the intramolecular hydrogen transfers from the five carbon positions to the oxygen atom of 2‐pentoxy and then followed by successive transfers from the unstable hydroxy radical to the final stable one. There are five paths of hydrogen transfer discussed, which include the transition structures of pseudo three‐, four‐, five‐, and six‐membered rings. The results indicated that the rate constant of the process via six‐membered ring transition state calculated at the B3LYP/6‐311++G** level was close to the experimental value and it had the lowest calculated energy barrier among all, 8.63 kcal/mol. We also studied the isomerization barriers of the first‐stage product to form the most stable conformation via possible paths. The calculated lowest barrier was 18.41 kcal/mol via a five‐membered ring process. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Reactivity descriptors applied to the study of cobalt porphyrin and their aza derivatives
Authors: Cárdenas‐Jirón Gloria I.
Published: December 2002

A theoretical study at the density functional level of theory (ROB3LYP/3‐21G*) of the reactivity of cobalt porphyrin (CoP) and their aza derivatives (CoP(xN)) by using global and local indexes is presented. First, vertical ionization potentials and electronic affinities are calculated to determine global reactivity descriptors such as the chemical potential (μ), molecular hardness (η), and electrophilicity (ω). In general, it is found that η and ω increase with the inclusion of aza‐N atoms in the cobalt porphyrin. The cobalt condensed Fukui function (f) and cobalt condensed electrostatic potential (EPCo) for the set of CoP(xN) are also determined. We obtained that f decreases with the increase of aza‐N atoms, which indicates that a minimum Fukui function is preferred for hard–hard interactions, in agreement with previous results (Cárdenas‐Jirón, G. J. J Phys Chem A 2002, 106, 3202). Results obtained for EPCo indicates that the increase of aza‐N atoms leads to a more electrophilic site for the cobalt atom that is also stated at a global level through the results of ω, which are referred to the molecule as a whole. It is concluded that global and local descriptors are complementary in this reactivity study and both give enough information to rationalize the effect of the inclusion of aza‐N atoms in the porphyrin upon the reactivity. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Work Attitudes, Employment Barriers, and Mental Health Symptoms in a Sample of Rural Welfare Recipients
Authors: Taylor Lorraine C.
Published: December 2002

Most of the extant research on welfare reform has neglected to consider the experiences of families in rural settings. Fifty women receiving welfare for their dependent children in a rural community were interviewed about their work experiences and aspirations, barriers to employment and service use, as well as mental health and social support. The findings indicate that the majority of participants were connected to the labor force and expressed positive attitudes about work. Barriers to employment (lack of available jobs, child care) and service use (transportation, inconvenient office hours) were endorsed. Perceived social support was negatively related to depression symptoms and positively related to self‐efficacy and self‐esteem. The importance of understanding the life experiences of welfare recipients in different contexts is discussed.
Determinants of Social Support Among Low‐Income Mothers: A Longitudinal Analysis
Authors: Green Beth L. , Rodgers Angela
Published: December 2002

This study examined the reciprocal relationships between perceived mastery, stress, and three functional areas of social support: tangible support, informational support, and belongingness support. Data were collected during two face‐to‐face interviews with a sample of low‐income, primarily African‐American mothers, conducted approximately 1 year apart. Consistent with predictions, initial levels of mastery predicted higher subsequent levels of instrumental social supports (tangible and advice support), but were unrelated to belonging support. Conversely, initial levels of tangible support were predictive of later mastery. Perceived stress did not account for any additional variance in subsequent support, although initial levels of belonging support only did predict reduced stress at Time 2. Results suggest that successful attempts to garner instrumental supports is an important contributor to individuals' sense of self‐efficacy, at the same time, self‐efficacy leads to more successful use of existing social support systems. These findings point to the importance of having both available tangible support networks as well as close emotional supports for low‐income parents. The importance of using longitudinal, multidimensional analyses to better understand the social support process is discussed.
Understanding Dignity in the Lives of Homeless Persons
Authors: Miller Alison B. , Keys Christopher B.
Published: December 2002

The current investigation is a planned, systematic study of dignity as critical to understanding the experience of homelessness and improving services and programs for the homeless. Specifically, we conducted a thematic content analysis of interviews with 24 homeless men and women to identify their perception of specific environmental events that validate and invalidate dignity. In addition, we explored the impact that these events have on homeless persons. Eight types of events were identified that sustain dignity such as being cared for by staff and having resources available to meet basic needs. Eight types of events were found that undermine dignity, such as being yelled at or insulted by staff persons and having staff use rules in an excessive and arbitrary way. Two outcomes followed the sustenance of dignity including increased self‐worth and motivation to exit homelessness. Three outcomes followed the undermining of dignity including anger, depression, and feelings of worthlessness. The results suggest that dignity is an important variable to consider in understanding the experience of homelessness. Policies and programs that support validating the dignity of homeless persons are encouraged.
Correlates of Employment Among Welfare Recipients: Do Psychological Characteristics and Attitudes Matter?
Authors: Kalil Ariel , Schweingruber Heidi A. , Seefeldt Kristin S.
Published: December 2002

This study examines whether and how a wide range of potential barriers to work,including psychological characteristics and attitudes, are associated with current employment in a recent sample of welfare recipients in Michigan (N = 672). Psychological factors include measures of depressive symptoms, work attitudes, and perceived risks associated with leaving welfare. Over and above demographic, economic, and contextual factors, positive psychological characteristics and attitudes were found to be moderately associated with currently being employed. Implications for welfare‐to‐work programs and policy are discussed.
Promoter Characterization and Expression of the Gene Coding for the Human GM2 Activator Protein
Authors: Beccari Tommaso , Balducci Chiara , Aisa M. Cristina , Della Fazia M. Agnese , Servillo Giuseppe , Orlacchio Aldo
Published: December 2002

Genomic clones of the human GM2 activator protein have been isolated and analyzed. The 5′ region of the gene demonstrated promoter activity as ascertained by its ability to drive luciferase gene expression in transfected COS cells. This sequence contains GC rich region and several putative promoter elements were present, including Sp1, AP2, cAMP-responsive element, and B-cell-specific activating protein. Analysis of tissue distribution of the GM2 activator protein gene revealed tissue-specific variations in transcript levels. Placenta, bone marrow, mammary gland, bladder, lymph node, and spleen had the highest mRNA levels.
Membrane Fusion Induced by Phospholipase C and Sphingomyelinases
Authors: Goñi Félix M. , Alonso Alicia
Published: December 2002

In the past decade lipid vesicle fusion induced by either bacterial PC-preferring phospholipase C, phosphatidylinositol-specific phospholipase C, sphingomyelinase, or a combination of phospholipase C and sphingomyelinase has been demonstrated. In the present paper, the experimental evidence is reviewed, and discussed in terms of the underlying molecular mechanisms of fusion, and of the possible physiological relevance of these findings.
Searching for a Normal Life: Personal Accounts of Adults With Schizophrenia, Their Parents and Well‐Siblings
Authors: Stein Catherine H. , Wemmerus Virginia A.
Published: December 2002

Using a life course perspective, the research examines personal accounts of adults with schizophrenia, and their parents and well‐siblings from six families. Accounts of multiple members of the same family, including the family member with schizophrenia, are used to describe how families understand and accommodate life changes that result from the illness. Families describe the loss of a “normal life” as one of the most devastating aspects of schizophrenia. We present the personal and social losses described by adults with schizophrenia and their well family members, and document families' search for ways that their ill family member can achieve or maintain valued social roles. The concerns of well family members for the future of the ill family member and ways families contemplate transfer of care issues are described. Implications of the study for community research and action are discussed.
Increase of Membrane Permeability of Mitochondria Isolated from Water Stress Adapted Potato Cells
Authors: Fratianni Alessandra , Pastore Donato , Pallotta Maria Luigia , Chiatante Donato , Passarella Salvatore
Published: December 2002

In order to gain some insight into mitochondria permeability under water stress, intact coupled mitochondria were isolated from water stress adapted potato cells and investigations were made of certain transport processes including the succinate/malate and ADP/ATP exchanges, the plant mitochondrial ATP-sensitive potassium channel (PmitoKATP) and the plant uncoupling mitochondrial protein (PUMP). The VmaxL values measured for succinate/malate and ADP/ATP carriers, as photometrically investigated, as well as the same values for the PmitoATP and the PUMP were found to increase; this suggested that mitochondria adaptation to water stress can cause an increase in the membrane permeability.
CASE REPORT: Partial effect of bromocriptine on lactose and galactose synthesis in a pregnant woman heterozygous for galactosaemia
Authors: Odièvre M. , Brivet M. , Rivière M‐F. , Labrune P.
Published: December 2002

Bromocriptine combined with galactose restriction in the matenal diet seems to be partially effective in decreasing endogenous lactose and galactose synthesis, monitored in a pregnant woman heterozygous for galactosaemia at risk of producing a homozygous infant.
Detection of neonatal argininosuccinate lyase deficiency by serum tandem mass spectrometry
Authors: Stadler S. , Gempel K. , Bieger I. , Pontz B. F. , Gerbitz K.‐D. , Bauer M. F. , Hofmann S.
Published: December 2002

Argininosuccinate lyase (ASL) deficiency (McKusick 207900) is an inborn error of the urea cycle. The leading symptom is progressive hyperammonaemia, which is a life‐threatening condition, particularly in patients with a neonatal onset. Early diagnosis and treatment of the hyperammonaemia are necessary to improve survival and the long‐term outcome of ASL‐deficient patients. Currently, the diagnosis of ASL deficiency is based on the measurement of urea cycle intermediates and amino acids by automated quantitative ion exchange chromatography in plasma and urine. Here, we report a newborn presenting with coma and severe hyperammonaemia. ASL deficiency was suspected on the basis of an adapted tandem mass spectrometric (MS‐MS) procedure which allows determination of argininosuccinate in addition to the amino acids in serum samples. MS‐MS measurements revealed a characteristic increase of argininosuccinate, a moderate increase of citrulline, and lowered levels of arginine and ornithine in the serum of the patient. The diagnosis was confirmed by the detection of a novel homozygous frameshift mutation in exon 14 of the argininosuccinate lyase gene. We propose MS‐MS as a diagnostic tool suitable for the rapid detection of specific alterations in the amino acid spectra caused by ASL deficiency.
Glycine N‐methyltransferase deficiency: A novel inborn error causing persistent isolated hypermethioninaemia
Authors: Mudd S. H. , Cerone R. , Schiaffino M. C. , Fantasia A. R. , Minniti G. , Caruso U. , Lorini R. , Watkins D. , Matiaszuk N. , Rosenblatt D. S. , Schwahn B. , Rozen R. , LeGros L. , Kotb M. , Capdevila A. , Luka Z. , Finkelstein J. D. , Tangerman A. , Stabler S. P. , Allen R. H. , Wagner C.
Published: December 2002

This paper reports clinical and metabolic studies of two Italian siblings with a novel form of persistent isolated hypermethioninaemia, i.e. abnormally elevated plasma methionine that lasted beyond the first months of life and is not due to cystathionine β‐synthase deficiency, tyrosinaemia I or liver disease. Abnormal elevations of their plasma S‐adenosylmethionine (AdoMet) concentrations proved they do not have deficient activity of methionine adenosyltransferase I/III. A variety of studies provided evidence that the elevations of methionine and AdoMet are not caused by defects in the methionine transamination pathway, deficient activity of methionine adenosyltransferase II, a mutation in methylenetetrahydrofolate reductase rendering this activity resistant to inhibition by AdoMet, or deficient activity of guanidinoacetate methyltransferase. Plasma sarcosine (N‐methylglycine) is elevated, together with elevated plasma AdoMet in normal subjects following oral methionine loads and in association with increased plasma levels of both methionine and AdoMet in cystathionine β‐synthase‐deficient individuals. However, plasma sarcosine is not elevated in these siblings. The latter result provides evidence they are deficient in activity of glycine N‐methyltransferase (GNMT). The only clinical abnormalities in these siblings are mild hepatomegaly and chronic elevation of serum transaminases not attributable to conventional causes of liver disease. A possible causative connection between GNMT deficiency and these hepatitis‐like manifestations is discussed. Further studies are required to evaluate whether dietary methionine restriction will be useful in this situation.
SHORT REPORT: A common 2 bp deletion mutation in the glucose‐6‐phosphatase gene in Indian patients with glycogen storage disease type Ia
Authors: Meaney C. , Cranston T. , Lee P. , Genet S.
Published: December 2002

This study reports a novel mutation which may be prevalent in Indian patients with glycogen storage disease type Ia.
Dreams and exposure therapy in PTSD
Authors: Rothbaum Barbara Olasov , Mellman Thomas Alan
Published: December 2002

Exposure therapy is a well‐established treatment for PTSD that requires the patient to focus on and describe the details of a traumatic experience. Nightmares that refer to or replicate traumatic experiences are prominent and distressing symptoms of PTSD and appear to exacerbate the disorder. With this apparent paradox in mind, exposure therapy and the literature on sleep and PTSD are reviewed in the context of the relationship between therapeutic exposure and exposure to traumarelated stimuli that occurs in dreams. It is concluded that nightmares that replay the trauma and disrupt sleep do not meet requirements for therapeutic exposure, whereas other dreaming may aid in the recovery from trauma.
Predictors of PTSD symptom severity and social reactions in sexual assault victims
Authors: Ullman Sarah E. , Filipas Henrietta H.
Published: December 2002

Demographics, assault variables, and postassault responses were analyzed as correlates of PTSD symptom severity in a sample of 323 sexual assault victims. Regression analyses indicated that less education, greater perceived life threat, and receipt of more negative social reactions upon disclosing assault were each related to greater PTSD symptom severity. Ethnic minority victims reported more negative social reactions from others. Victims of more severe sexual victimization reported fewer positive, but more negative reactions from others. Greater extent of disclosure of the assault was related to more positive and fewer negative social reactions. Telling more persons about the assault was related to more negative and positive reactions. Implications of these results for developing contextual theoretical models of rape‐related PTSD are discussed.
Financing Social Security and Regulation (EEC) 1408/71
Authors: Verschueren Herwig
Published: December 2002

This article seeks to provide a clearer picture of the role of methods for funding social security benefits in EC Coordination Regulation 1408/71. In past literature and in the case law surrounding Regulation 1408/71, this role has seldom been mentioned. However, this is changing in light of increasing numbers of questions emerging at both the policy-making level and at the level of Court of Justice proceedings.

The first part of this paper deals with the role of different methods of financing social security in determining the material scope of the coordination regulation and the question of whether the method of financing certain benefits has a bearing on this material scope. The second part deals with the existing link within the coordination context between paying or having paid contributions and entitlement to benefits. I discuss, inter alia, the extent to which benefit levels are determined by the same legislation as that which determines contribution levels. I examine the extent to which Member States collecting contributions are also responsible for bearing the cost of the corresponding benefits and the extent to which a person who is paying or has paid contributions is entitled to benefits corresponding to those contributions.

In light of this examination of the facts as they stand, I endeavour to consider possible alternatives, including the desirability of having a more direct link within the coordination context between payment of contributions and entitlement to benefits.
Very low‐density lipoprotein apolipoprotein B‐100 turnover in glycogen storage disease type Ia (von Gierke disease)
Authors: Wierzbicki A. S. , Watts G. F. , Lynas J. , Winder A. F. , Wray R.
Published: December 2002

Mixed hyperlipidaemia is a common finding in glycogen storage disease type Ia (GSD Ia). Although cross‐sectional studies have demonstrated increases in intermediate‐density lipoproteins (IDLs) and reductions in lipoprotein lipase activity, no studies have investigated the dynamics of apolipoprotein B‐100 (apo B) metabolism in GSD Ia. This study investigated apoB turnover in GSD Ia using an exogenous labelling method in one sib from a kinship with established GSD Ia. The study demonstrated normal hepatic secretion of very low‐density lipoprotein (VLDL), but hypocatabolism of VLDL, probably due to lack of lipoprotein lipase activity. The production rate of IDL was slightly increased, but the turnover rate of low‐density lipoprotein was normal. The findings suggest that, as well as a corn starch diet and dietary fat restriction, treatment of severe mixed hyperlipidaemia in GSD Ia and its attendant risk of pancreatitis should possibly involve fibrates that activate lipoprotein lipase and may enhance the clearance of IDL, rather than ω‐3 fatty acids, which principally suppress hepatic secretion of VLDL.
Successful pregnancy outcome in atypical hyperglycinaemia
Authors: Ellaway C. J. , Mundy H. , Lee P. J.
Published: December 2002

A female patient with atypical nonketotic hyperglycinaemia is reported having undergone two successful pregnancies. During pregnancy, plasma glycine was raised. Neuropsychometric outcome of both offspring shows IQs average for population.