bluuebunny/crossref_metadata_2025_split huggingface dataset:
Energetics and spin- and Λ-doublet selectivity in the infrared multiphoton dissociation HN3(X̃ 1A′)→N2(X 1Σ+g)+NH(X 3Σ−,a 1Δ): Theory
Authors: Alexander Millard H. , Werner Hans-Joachim , Dagdigian Paul J. 
Published: July 2002

An investigation of the energetics and mechanism of the dissociation of ground state HN3(X̃ 1A′) into ground state N2(X 1∑+g)+NH(X 3∑−) products is presented. This process, which can be induced by multiphoton infrared pumping, occurs through a crossing between the lowest-energy singlet potential energy, which correlates asymptotically with electronically excited NH products (a 1Δ), and the lowest triplet surface. By means of ab initio CASSCF and MCSCF-CI calculations we have determined that the geometry at the minimum singlet–triplet crossing corresponds to an approximately linear N3 backbone with a perpendicular NH bond. The interior N–N distance is ∼3.6 bohr. This transition state lies ∼12 500 cm−1 above the energy of X̃ 1A′ state of HN3 at the experimental equilibrium geometry. Since the N–N and N–H bonds are perpendicular at this transition state, there will be no torques tending to twist the system out of a planar geometry. The crucial singlet–triplet coupling occurs because the HN3 wave function in the region of this transition state can be considered an equal admixture of N2(X)⋅NH(a 1Δ) and
N2(X)⋅NH(b 1∑+). Since the ground state HN3 wave function as well as the relevant spin–orbit Hamiltonian are symmetric with respect to reflection of the spatial and spin components of all the electrons in the plane of the molecule, and since the NH fragment must rotate in the plane of the initital HN3 molecule if the dissociation is planar, NH products can be formed only in states in which the wave function (electronic+rotational) is also symmetric with respect to this operation. For a molecule in a 3∑− electronic state the wave functions in only the F1 and F3 multiplets will be symmetric so that one would expect population in only the F1 and F3 levels. A similar symmetry argument implies that the NH products formed in the lowest spin-allowed channel [N2(X 1∑+g)+NH(a 1Δ)] will be found predominantly in the Δ(A′) Λ-doublet state, which is symmetric with respect to reflection of the spatial coordinates of the electrons in the plane of rotation. This spin- and Λ-doublet selectivity has been found experimentally by Stephenson, Casassa, and King (accompanying article). The implications of similar spin selectivity in other photodissociation processes leading to molecules in 3∑− states, e.g., SO(X 3∑−) and O2(X 3∑−g), are also considered.
Statistical and eddy structure approaches to turbulent mixing
Authors: Hunt J. C. R. , Malik N. A. , Perkins R. J. 
Published: July 2002

For industrial and environmental purposes there is a need for broad concepts and general models to describe many types of mixing processes and situations. These concepts arise from exact conversation results,1 and the similarity of the velocity fields and the particle displacements in turbulent fields at high Reynolds number, especially in the presence of shear. However, the design and control of mixing, like other kinds of turbulent problems, is usually improved by considering quasideterministic models of how turbulent eddies affect the process. Such models are changing with new computations and experimental studies of turbulence structure. Mixing involves continuously bringing together volumes of fluid with different concentrations on small enough scales to effect mixing between molecules.
The Lagrangian statistical analysis of the displacements of fluid elements enables joint moments of concentration to be calculated in terms of initial concentration distributions in the absence of diffusion and reaction.2 This macromixing analysis in conjunction with simple concepts of small-scale mixing leads to models and a new understanding for many mixing processes, e.g., concentration fluctuations, simple chemical reactions, and the effects of varying the mean shear, the velocity spectra and the molecular diffusivity.3–7 Since extreme pollution concentrations and many complex chemical and physical processes can only be understood in a given scalar field, rather than from statistics of scalar fields, it is necessary to understand and model where and how mixing occurs in a single realization of the flow. This requires computing and/or measuring the evolving velocity and scalar fields in turbulent flows. Recent direct numerical simulations8–10 and kinematic simulations,11,12 i.e., velocity fields constructed from random Fourier modes, with observed or idealized two-point, two-time Eulerian and Lagrangian spectra, have shown (i) how surface areas expand exponentially, and volumes elongate only slightly;8,13 (ii) how scalar surfaces are deformed quite differently in different characteristic regions of turbulent flows; viz., vortical, eddy regions (rolling up into ‘‘fractal’’ surfaces), convergent–divergent, stagnating regions (stretching out, and nonfractal), and streaming regions (where tendrils form);14 (iii) how large volumes of matter disperse in particular events (which cannot be obtained from ensemble average statistics obtained from stochastic models based on displacements of one or two particles).15
Ambulance attendance at heroin overdose in Melbourne: the establishment of a database of Ambulance Service records
Authors: DIETZE PAUL M. , CVETKOVSKI STEFAN , RUMBOLD GREG , MILLER PETER 
Published: July 2002

AbstractThis paper presents some of the preliminary data extracted from a database of non‐fatal heroin overdoses attended by ambulances in metropolitan Melbourne. The database has been developed in order to provide interested parties with reliable, high quality and timely data on heroin‐related harm. Heroin overdose victims were defined as those people who were unconscious at the time the ambulance arrived and subsequently responded positively to the administration of naloxone. There were 388 heroin overdoses attended by ambulances in Melbourne over the period 1 November 1997–31 January 1998. The majority of victims were male (74 %) with an estimated mean age of 27.1 years. The overdoses occurred most commonly during the afternoon and evening, with Thursdays and Fridays most prominent. Police attendance was low (12%) and the vast majority of victims were not transported to hospital. An analysis by postcode revealed that the overdoses tended to be concentrated around a number of locations which have identified street heroin markets. The findings are discussed in relation to the utility of the data as an indicator of heroin‐related harm within the community and for informing overdose prevention initiatives.
Attitudes and practices of general practitioners training to work with drug‐using patients
Authors: Jacka David , Clode Danielle , Patterson Sharon , Wyman Kim 
Published: July 2002

AbstractThis study assessed the current attitudes, knowledge and practices of 26 inner metropolitan GPs training to work with drug‐users. In comparison to nicotine, alcohol and benzodiazepine, illicit drugs (such as opiates and amphetamines) were associated with significantly lower GP confidence, self‐reported effectiveness and general knowledge. GPs were also less likely to ask their patients about illicit drug‐use than other types of drugs. Older GPs were more confident, believed themselves to be more effective but had less general knowledge about all drug types than GPs under 40. Female doctors also reported lower levels of confidence. Self‐reported effectiveness and confidence did not show any association with accuracy of general knowledge about drugs. Although most GPs were very positive about their role in working with drug‐users, GPs tended to associate wanting to work with drug‐users with professional responsibility, rather than personal interest. These findings suggest that training programmes for GPs in the area of drug‐use need to be tailored to account for differing knowledge bases, but also tackle the more difficult task of addressing attitudes and self‐perceptions of the role GPs play in dealing with drug‐use.
Examining interaction in language therapy
Authors: Horton Simon , Byng Sally 
Published: July 2002

AbstractDiscussions around a ‘theory of therapy’ have prompted attempts to delineate the components of therapy for language impairment in aphasia. Here it is suggested that the therapy components associated with how language therapy is enacted need more precise specification, especially in relation to what is entailed by interaction between therapist and person with aphasia. Presented too is a system used for the analysis of interaction in language impairment therapy for aphasia and its possible applications are discussed. Components of the system are described and a sample analysis presented. The methodological difficulties entailed in making comparisons of therapy enactment are discussed. It is suggested furthermore that unless more is known about precisely defined interactions in therapy, it will be difficult to answer basic questions not only about how language therapy is being carried out, but also, subsequently, whether the ways in which therapy tasks are enacted have a significant impact on the outcome.
Enhancing communication in jargon aphasia: a small group study of writing therapy
Authors: Robson Jo , Marshall Jane , Chiat Shula , Pring Tim 
Published: July 2002

AbstractPeople with jargon aphasia have severely disordered and incomprehensible speech that may be resistant to therapeutic intervention. In this study, we treated written output and examined whether it assisted communication for these clients. In stage one of the study, anagram sorting, delayed copying and lexical decision tasks were used to investigate the residual knowledge of written words in a group of ten people with jargon aphasia. Evidence of the presence of orthographic knowledge was taken as an indication that writing might be a useful focus for therapy. This hypothesis was explored in stage two with six clients. A personally useful vocabulary was selected for each, and copying, word completion and written picture‐naming tasks were used in therapy to improve written production of these words. The clients made progress in written naming. However, they showed little change on a ‘message’ assessment that tested their ability to use the written words to convey messages. Stage three targeted communicative writing. Here, three of the clients received ‘message therapy’, which encouraged them to relate treated words to functional messages and to communicate them to a partner. The clients improved on the message assessment and observation of their communication and reports from relatives suggested that they made functional use of writing in a range of communication settings.
Written communication in undifferentiated jargon aphasia: a therapy study
Authors: Robson Jo , Pring Tim , Marshall Jane , Morrison Sarah , Chiat Shula 
Published: July 2002

AbstractA subject, R.M.M., with a 2‐year history of jargon aphasia is described. At the beginning of this study she had minimal meaningful spoken output and showed little awareness of her speech despite having relatively well‐preserved auditory comprehension. Her spoken output had proved resistant to earlier periods of therapy. In contrast, R.M.M.'s written output showed some ability to access orthographic information and monitoring of this modality was shown by an acute awareness of her errors. A 3‐stage therapy programme is described. This was designed to improve R.M.M.'s writing of single words and to encourage use of writing as an alternative means of communication. The initial stage of therapy aimed to increase R.M.M.'s access to written word forms by use of picture stimuli. She showed significant improvement in writing treated items in response to pictures both immediately after therapy and at re‐assessment 6 weeks later. Despite the acquisition of these skills, R.M.M. failed to use them in communicative contexts. A second stage of therapy replicated the results of the first and sought to facilitate R.M.M.'s functional use of her written vocabulary by asking her to write words to spoken questions. She again showed improved written naming of the treated items and could now produce written names appropriately in a questionnaire‐type assessment. Generalization of this ability extended to items that had not been trained in this way. Functional use of writing in everyday communication remained absent, however. The final stage of therapy made explicit the potential links between items which R.M.M. could now write and functional messages which they might convey. She again showed significant changes in the acquisition of new vocabulary and, encouragingly, progress was also seen in her use of the strategy in functional communication. R.M.M.'s speech is almost entirely incomprehensible. It has remained unchanged for 2 years and has not responded to therapy. Relatively wellpreserved auditory comprehension and good monitoring of written output allowed therapy to effectively target a small written vocabulary. Despite significant progress in the acquisition of new items, transfer of this skill to functional communication was initially absent. Further therapy which specifically targeted the impairment causing this failure was needed before functional use was seen. The potential for treating written output in cases of jargon aphasia which have been resistant to therapy for spoken language is discussed.
Imaging Signal Transduction in Living Cells with GFP‐Based Probes
Authors: Zaccolo Manuela , Pozzan Tullio 
Published: July 2002

AbstractSince the cloning and the eterologous expression of the Green Fluorescence Protein (GFP), a number of applications have been reported where protein location within the cell or gene expression is revealed by fluorescent imaging of living cells. Modified GFPs, however, can now be exploited not only as a fluorescent reporter but also as a dynamic marker of intracellular signalling events, such as fluctuations in the levels of the second messengers Ca2+ and cAMP, or as a probe for detecting changes in pH in various cell compartments. These genetically manipulated GFPs allow monitoring of the biochemistry of the cell in real time and thus offer the possibility to gain a more precise view of the functioning of live cells.
Intrinsic Neuronal Determinants Locally Regulate Extrasynaptic and Synaptic Growth at the Adult Neuromuscular Junction
Authors: Caroni Pico , Aigner Ludwig , Schneider Corinna 
Published: July 2002

Long-term functional plasticity in the nervous system can involve structural changes in terminal arborization and synaptic connections. To determine whether the differential expression of intrinsic neuronal determinants affects structural plasticity, we produced and analyzed transgenic mice overexpressing the cytosolic proteins cortical cytoskeleton–associated protein 23 (CAP-23) and growth-associated protein 43 (GAP-43) in adult neurons.
Like GAP-43, CAP-23 was downregulated in mouse motor nerves and neuromuscular junctions during the second postnatal week and reexpressed during regeneration. In transgenic mice, the expression of either protein in adult motoneurons induced spontaneous and greatly potentiated stimulus-induced nerve sprouting at the neuromuscular junction. This sprouting had transgene-specific features, with CAP-23 inducing longer, but less numerous sprouts than GAP-43. Crossing of the transgenic mice led to dramatic potentiation of the sprout-inducing activities of GAP-43 and CAP-23, indicating that these related proteins have complementary and synergistic activities. In addition to ultraterminal sprouting, substantial growth of synaptic structures was induced. Experiments with pre- and postsynaptic toxins revealed that in the presence of GAP-43 or CAP-23, sprouting was stimulated by a mechanism that responds to reduced transmitter release and may be independent of postsynaptic activation.
These results demonstrate the importance of intrinsic determinants in structural plasticity and provide an experimental approach to study its role in nervous system function.
A Role for the Tec Family Tyrosine Kinase Txk in T Cell Activation and Thymocyte Selection
Authors: Sommers Connie L. , Rabin Ronald L. , Grinberg Alexander , Tsay Henry C. , Farber Joshua , Love Paul E. 
Published: July 2002

Summary
Recent data indicate that several members of the Tec family of protein tyrosine kinases function in antigen receptor signal transduction. Txk, a Tec family protein tyrosine kinase, is expressed in both immature and mature T cells and in mast cells. By overexpressing Txk in T cells throughout development, we found that Txk specifically augments the phospholipase C (PLC)-γ1–mediated calcium signal transduction pathway upon T cell antigen receptor (TCR) engagement. Although Txk is structurally different from inducible T cell kinase (Itk), another Tec family member expressed in T cells, expression of the Txk transgene could partially rescue defects in positive selection and signaling in itk−/− mice. Conversely, in the itk+/+ (wild-type) background, overexpression of Txk inhibited positive selection of TCR transgenic thymocytes, presumably due to induction of cell death. These results identify a role for Txk in TCR signal transduction, T cell development, and selection and suggest that the Tec family kinases Itk and Txk perform analogous functions.
Weighting hidden Markov models for maximum discrimination.
Authors: Karchin R , Hughey R 
Published: July 2002

Abstract
MOTIVATION: Hidden Markov models can efficiently and automatically build statistical representations of related sequences. Unfortunately, training sets are frequently biased toward one subgroup of sequences, leading to an insufficiently general model. This work evaluates sequence weighting methods based on the maximum-discrimination idea. RESULTS: One good method scales sequence weights by an exponential that ranges between 0.1 for the best scoring sequence and 1.0 for the worst. Experiments with a curated data set show that while training with one or two sequences performed worse than single-sequence Probabilistic Smith-Waterman, training with five or ten sequences reduced errors by 20% and 51%, respectively. This new version of the SAM HMM suite outperforms HMMer (17% reduction over PSW for 10 training sequences), Meta-MEME (28% reduction), and unweighted SAM (31% reduction). AVAILABILITY: A WWW server, as well as information on obtaining the Sequence Alignment and Modeling (SAM) software suite and additional data from this work, can be found at http://www.cse.ucse. edu/research/compbio/sam.html
Development of the receptor database (RDB): application to the endocrine disruptor problem.
Authors: Nakata K , Takai T , Kaminuma T 
Published: July 2002

Abstract
MOTIVATION: To represent various aspects of receptors effectively, we developed the receptor database (RDB), using an object-oriented database management system ACEDB and the Internet/WWW technology. RESULTS: RDB was constructed so that the system collects data items such as attributes of proteins from distributed data sources of the Internet, and so that it provides various viewing tools effectively, depending on different types of receptor data. Such sources include standard international biological databases such as the up-to-date database of PIR, Swiss Prot, PDB, GenBank and GDB. Application to the endocrine disruptor problem is presented. AVAILABILITY: RDB is available through the Internet at http://impact.nihs.go.jp/RDB.html.
MPBLAST : improved BLAST performance with multiplexed

queries
Authors: Korf Ian , Gish Warren 
Published: July 2002

Abstract
Summary: We have developed a program, MPBLAST, that increases the throughput of batch BLASTN searches by multiplexing (concatenating) query sequences and thereby reducing the number of actual database searches performed. Throughput was observed to increase in reciprocal proportion to the component sequence length. For sequencing read-sized queries of 500 bp, an order of magnitude speed-up was seen.
Availability: Free (see http://blast.wustl.edu)
Contact: {ikorf, gish}@watson.wustl.edu
Generation of ligand‐receptor alliances by “SEA” module‐mediated cleavage of membrane‐associated mucin proteins
Authors: Wreschner Daniel H. , McGuckin Michael A. , Williams Stefanie J. , Baruch Amos , Yoeli Merav , Ziv Ravit , Okun Liron , Zaretsky Joseph , Smorodinsky Nechama , Keydar Iafa , Neophytou Pavlos , Stacey Martin , Lin His‐Hsien , Gordon Siamon 
Published: July 2002

AbstractA mechanism is described whereby one and the same gene can encode both a receptor protein as well as its specific ligand. Generation of this receptor–ligand partnership is effected by proteolytic cleavage within a specific module located in a membrane resident protein. It is postulated here that the “SEA” module, found in a number of heavily O‐linked glycosylated membrane‐associated proteins, serves as a site for proteolytic cleavage. The subunits generated by proteolytic cleavage of the SEA module reassociate, and can subsequently elicit a signaling cascade. We hypothesize that all membrane resident proteins containing such a “SEA” module will undergo cleavage, thereby generating a receptor–ligand alliance. This requires that the protein subunits resulting from the proteolytic cleavage reassociate with each other in a highly specific fashion. The same SEA module that serves as the site for proteolytic cleavage, probably also contains the binding sites for reassociation of the resultant two subunits. More than one type of module can function as a site for proteolytic cleavage; this can occur not only in one‐pass membrane proteins but also in 7‐transmembrane proteins and other membrane‐associated proteins. The proposal presented here is likely to have significant practical consequences. It could well lead to the rational design and identification of molecules that, by binding to one of the cleaved partners, will act either as agonists or antagonists, alter signal transduction and, hence, cellular behavior.
Long-term Cognitive Trajectory After Total Joint Arthroplasty
Authors: Vassilaki Maria , Kremers Walter K. , Machulda Mary M. , Knopman David S. , Petersen Ronald C. , Laporta Mariana L. , Berry Daniel J. , Lewallen David G. , Maradit Kremers Hilal 
Published: November 2022

ImportanceIndividuals with total joint arthroplasty (TJA) have long-term exposure to metal-containing implants; however, whether long-term exposure to artificial implants is associated with cognitive function is unknown.ObjectiveTo compare long-term cognitive trajectories in individuals with and without TJA.Design, Setting, and ParticipantsThis population-based cohort study assessed serial cognitive evaluations of 5550 participants (≥50 years of age) from the Mayo Clinic Study of Aging between November 1, 2004, and December 31, 2020.ExposuresTotal joint arthroplasty of the hip or the knee.Main Outcomes and MeasuresLinear mixed-effects models were used to compare the annualized rate of change in global and domain-specific cognitive scores in participants with and without TJA, adjusting for age, sex, educational level, apolipoprotein E ε4 carrier status, and cognitive test practice effects.ResultsA total of 5550 participants (mean [SD] age at baseline, 73.04 [10.02] years; 2830 [51.0%] male) were evaluated. A total of 952 participants had undergone at least 1 TJA of the hip (THA, n = 430) or the knee (TKA, n = 626) before or after entry into the cohort. Participants with TJA were older, more likely to be female, and had a higher body mass index than participants without TJA. No difference was observed in the rate of cognitive decline in participants with and without TJA until 80 years of age. A slightly faster cognitive decline at 80 years or older and more than 8 years from surgery was observed (b = −0.03; 95% CI, −0.04 to −0.02). In stratified analyses by surgery type, the faster decline was observed primarily among older participants with TKA (b = −0.04; 95% CI, −0.06 to −0.02).Conclusions and RelevanceIn this cohort study, long-term cognitive trajectories in individuals with and without TJA were largely similar except for a slightly faster decline among the oldest patients with TKA; however, the magnitude of difference was small and of unknown clinical significance.