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At least 1,279 records · Page 71Linked to original sources
PubMed1984

Purification and NH2-terminal amino acid sequencing of the beta subunit of a human T-cell antigen receptor.

To obtain information about the structural basis for T-cell antigen recognition, a T3-associated Ti receptor molecule was isolated from crude membranes of the REX human thymic tumor line and purified by affinity chromatography with an anti- clonotypic monoclonal antibody in conjunction with preparative gel electrophoresis. NH2-terminal amino acid sequencing of the beta subunit unambiguously identified the amino acids in positions 2-12. Comparative protein sequence analysis by computer search demonstrated that this Ti beta sequence bore weak, but definite, homology to the first framework of the variable region of human lambda light chain. Anti-sera to a synthetic peptide corresponding to positions 2-11 precipitated the denatured Ti beta subunit from REX, thus confirming the above sequence. This information suggests that the Ti beta subunit is distantly related to human immunoglobulin lambda light chain and, moreover, should be of use in the molecular cloning of the Ti beta gene.

Amino Acid Sequence↗
PubMed2004

Early mortality in twin pregnancies complicated by premature rupture of membranes in the United States.

There is little information on mortality among multiple gestations complicated by premature rupture of membranes (PROM). In this study, we estimated the occurrence of the components of early mortality (stillbirth, neonatal and infant mortality) among twin pregnancies using the generalised estimating equation framework to account for intra-cluster correlations. Using the population-attributable risk, we also computed the level of excess mortality that could be averted by preventing PROM. Our findings reveal that the likelihood of stillbirth (odds ratio (OR) = 1.88; 95% confidence interval (CI)=1.66-2.13), neonatal mortality (OR=3.45; 95% CI=3.18-3.74) and infant mortality (OR=3.26; 95% CI=3.03-3.50) was significantly higher among twin pregnancies exposed to PROM. Approximately 6% of all stillbirths, 15% of neonatal mortality and 14% of infant mortality among twins in the United States are attributable to PROM. We conclude that PROM is associated with an increased level of early mortality among twins.

Adult↗
PubMed2005

Survival probability of diffusion with trapping in cellular neurobiology.

The problem of diffusion with absorption and trapping sites arises in the theory of molecular signaling inside and on the membranes of biological cells. In particular, this problem arises in the case of spine-dendrite communication, where the number of calcium ions, modeled as random particles, is regulated across the spine microstructure by pumps, which play the role of killing sites, while the end of the dendritic shaft is an absorbing boundary. We develop a general mathematical framework for diffusion in the presence of absorption and killing sites and apply it to the computation of the time-dependent survival probability of ions. We also compute the ratio of the number of absorbed particles at a specific location to the number of killed particles. We show that the ratio depends on the distribution of killing sites. The biological consequence is that the position of the pumps regulates the fraction of calcium ions that reach the dendrite.

Animals↗
PubMed2001

Evidence of double criticality in a fluid model with density-dependent interactions.

Evidence of a liquid-liquid equilibrium in simple fluids has recently been exposed for a density-dependent pair potential in the framework of a van der Waals theory. Here this double criticality is investigated by means of computer simulation, a perturbation theory, and integral equation theory. It is found that the critical point estimated from the integral equation thermodynamics is not associated with divergent correlations. To cope with these features, a special simulation procedure, based on the definition of local densities, is devised. Monte Carlo calculations confirm the existence of two critical points, in agreement with the predictions of perturbation theory.

Journal Article↗
PubMed2001

Coherent gluon production in very-high-energy heavy-ion collisions.

The early stages of a relativistic heavy-ion collision are examined in the framework of an effective classical SU(3) Yang-Mills theory in the transverse plane. We compute the initial energy and number distributions, per unit rapidity, at midrapidity, of gluons produced in high-energy heavy-ion collisions. We discuss the phenomenological implications of our results in light of the recent Relativistic Heavy-Ion Collider data.

Journal Article↗
PubMed1992

Comparison of algorithms for tracking short-term changes in arterial circulation parameters.

Three recursive methods especially suited for identification of systems with rapidly changing parameters are applied to tracking of the viscoelastic properties of the systemic arterial bed. These methods include two least squares (LS) algorithms with constant or variable forgetting factor (RLS and LSVF) and a LS algorithm incorporating both a constant forgetting factor and covariance modification (CFCM). The methods are presented in a unified framework and their sensitivity with respect to the design variables is investigated using noisy data from computer simulations. All analysed methods have shown themselves to be able to satisfactory track rapid changes in peripheral resistance. The LSVF method, which offers slightly better performances than the classical RLS, may be preferred when calculation efficiency is the prime requirement. The CFCM algorithm, although maintaining reasonable simplicity, shows the best tracking ability also on varying of the noise sequence.

Algorithms↗
PubMed2006

A hybrid forward algorithm for RBF neural network construction.

This paper proposes a novel hybrid forward algorithm (HFA) for the construction of radial basis function (RBF) neural networks with tunable nodes. The main objective is to efficiently and effectively produce a parsimonious RBF neural network that generalizes well. In this study, it is achieved through simultaneous network structure determination and parameter optimization on the continuous parameter space. This is a mixed integer hard problem and the proposed HFA tackles this problem using an integrated analytic framework, leading to significantly improved network performance and reduced memory usage for the network construction. The computational complexity analysis confirms the efficiency of the proposed algorithm, and the simulation results demonstrate its effectiveness.

Algorithms↗
PubMed2005

A qualitative study of the impact of the implementation of advanced access in primary healthcare on the working lives of general practice staff.

BACKGROUND: The North American model of 'advanced access' has been emulated by the National Primary Care Collaborative in the UK as a way of improving patients' access in primary care. The aim of this study was to explore the impact of the implementation of advanced access on the working lives of general practice staff. METHODS: A qualitative study design, using semi-structured interviews, was conducted with 18 general practice staff: 6 GPs, 6 practice managers and 6 receptionists. Two neighbouring boroughs in southeast England were used as the study sites. NUD*IST computer software assisted in data management to identify concepts, categories and themes of the data. A framework approach was used to analyse the data. RESULTS: Whilst practice managers and receptionists saw advanced access as having a positive effect on their working lives, the responses of general practitioners (GPs) were more ambivalent. Receptionists reported improvements in their working lives with a change in their role from gatekeepers for appointments to providing access to appointments, fewer confrontations with patients, and greater job satisfaction. Practice managers perceived reductions in work stress from fewer patient complaints, better use of time, and greater flexibility for contingency planning. GPs recognised benefits in terms of improved consultations, but had concerns about the impact on workload and continuity of care. CONCLUSION: AA has improved working conditions for receptionists, converting their perceived role from gatekeeper to access facilitator, and for practice managers as patients were more satisfied. GP responses were more ambivalent, as they experienced both positive and negative effects.

Administrative Personnel↗
PubMed2001

n-CoDeR concept: unique types of antibodies for diagnostic use and therapy.

The n-CoDeR recombinant antibody gene libraries are built on a single master framework, into which diverse in vivo-formed complementarity determining regions (CDRs) are allowed to recombine. These CDRs are sampled from in vivo-processed and proof-read gene sequences, thus ensuring an optimal level of correctly folded and functional molecules. By the modularized assembly process, up to six CDRs can be varied at the same time, providing a possibility for the creation of a hitherto undescribed genetic and functional variation. The n-CoDeR antibody gene libraries can be used to select highly specific, human antibody fragments with specificities to virtually any antigen, including carbohydrates and human self-proteins and with affinities down into the subnanomolar range. Furthermore, combining CDRs sampled from in vivo-processed sequences into a single framework result in molecules exhibiting a lower immunogenicity compared to normal human immunoglobulins, as determined by computer analyses. The distinguished features of the n-CoDeR libraries in the therapeutic and diagnostic areas are discussed.

Animals↗
PubMed2005

The need of neuroinformatic approach in functional neurophysiology.

Despite the enormous growth in the number of facts and regularities observed in neuroscience, the current state of the field does not allow their integration in coherent theoretical frameworks. Neuroinformatics is a new research field devoted to development of neuroscience data bases together with computational models and analytical tools for sharing, integration and analysis of experimental data and the advancement of theories of nervous system function. From 1996 the OECD countries promote fostering neuroinformatics by eliminating the barriers that prevent cooperation and by providing incentives to potential participants. This activity was formulated in the Report on Neuroinformatics from The Global Science Forum Neuroinformatics Working Group of the OECD (2002) as well as in several printed publications by the Neuroinformatics group (Amari et al. 2002, Eckersley et al. 2003). This article summarizes the ideas presented in the Report and stresses the importance of analytical and modeling approach to functional neurophysiology.

Electroencephalography↗
PubMed1998

Transition probability cell cycle model with product formation.

A cell cycle population model based on the transition probability model of Smith and Martin (1973) has been extended to include product synthesis and export. The model handles two probable mechanisms. In the direct production model, the product is the protein. In the transcription model, the product is the specific mRNA. The protein is synthesized by translation of the specific mRNA and subsequently exported. In either case, the cell density is jointly distributed in the primary product and maturity age in the cell cycle. This extended model also is capable of describing a large range of conditions, including substrate dependent batch and continuous cultures. With the use of unity maturity-velocity (but the transition rate a function of limiting substrate), the model is shown to exhibit a negative growth association between the specific productivity of monoclonal antibodies from hybridomas and the dilution rates of a chemostat. Possibilities of maturity age dependent transcription and translation are considered, and the results show that these features can amplify the specific productivity negative association with specific growth rate. While this model may provide a partial elucidation of monoclonal antibody productivity in a chemostat, the present work provides a proper framework with which probable cell cycle dependent product formation can be analyzed rigorously with a comprehensive computational model.

Animals↗
PubMed2001

[Technical problems associated with the cold chain].

After having covered the current status of the cold chain in France, the author highlights the economic impact of refrigerated storage and processing involving refrigeration. Lose reduction is such that the return on investments is estimated as being roughly 3 years. In years to come, progress will be achieved in the field of plant design. Some information on design trends is provided. Operators in general, and carriers in particular, are faced with an increasingly complex regulatory framework leading to a competition imbalance. The current cold chain developmental trend is characterized by complex computer management of logistics: the flow of goods is modulated in order to meet the production to the distribution needs as cost effectively as possible. This logistic strategy enables management of downstream to upstream interfaces involving various operators. Finally, the author indicates the main causes of non-compliance with the cold chain, generally at retail and consumer levels.

France↗
PubMed2005

Risky decisions despite counter evidence: modeling a culture of safer sexual practices.

To create a culture of safe practices, we need to understand how and under what conditions the public makes risky decisions about their health. Because risky sexual behaviors are known to be common in young adults, we investigated their decision making regarding sexual activities that could incur a high risk of HIV infection. Sixty young urban adults maintained journals for two weeks and were interviewed regarding condom use and sexual history. We characterized four patterns of condom use behavior: consistent (35.0%), inconsistent (16.7%), consistent to inconsistent (35.0%), and inconsistent to consistent (13.3%). Directionality of reasoning was analyzed in the explanations provided for condom use decisions. The consistent and inconsistent patterns were associated with data-driven heuristic reasoning, where behavior becomes automated and is associated with a high level of confidence in one's judgment. In the other two patterns, the shift in behavior was due to a significant event that influenced a change in directionality to explanation-based reasoning. We discuss these results within the framework of identifying potentially high-risk groups for whom customized intervention strategies (such as computer-based educational programs) can be used to reduce risk, thereby creating a culture of safer sexual practices.

Adult↗
PubMed1984

The acute psychiatric diagnostic interview.

The general outline of a psychiatric diagnostic interview given in Table 1 includes some broad suggestions for the amount of time to spend on each section. As a structured interview based on a symptom checklist questionnaire yields higher frequency of reports of symptoms, it is advisable to follow this type of format rather than a totally unstructured interview technique. Sim recommends a structured format that lends itself to computerization. Griest and colleagues suggest a computer interview, and there are data supporting the diagnostic accuracy of such a system. Within the framework of any diagnostic interview, a thorough exploration of the 10 critical elements listed in Table 5 is essential for accurate diagnosis. This information, which is usually obtainable in about 30 minutes, will enable the clinician to make a preliminary diagnosis, decide upon pharmacotherapy, and determine if hospitalization is warranted. A more intensive but lengthy and time-consuming structured diagnostic interview is the Schedule for Affective Disorders (SADS), which is more appropriate for inpatients or patients being considered for a research protocol.

Acute Disease↗
PubMed1996

The EON model of intervention protocols and guidelines.

We present a computational model of treatment protocols abstracted from implemented systems that we have developed previously. In our framework, a protocol is modeled as a hierarchical plan where high-level protocol steps are decomposed into descriptions of more specific actions. The clinical algorithms embodied in a protocol are represented by procedures that encode the sequencing, looping, and synchronization of protocol steps. The representation allows concurrent and optional protocol steps. We define the semantics of a procedure in terms of an execution model that specifies how the procedure should be interpreted. We show that the model can be applied to an asthma guideline different from the protocols for which the model was originally constructed.

Adult↗
PubMed1992

Stress, computer-based work monitoring and measurement systems: a conceptual overview.

The design and implementation of computer-based work monitoring systems can result in changes in the organization, job and task. Electronic performance monitoring (EPM) systems are one type of change based on principles of work simplification and work rationalization. In this new work arrangement, control and coordination functions are allocated to the computer. The supervisor becomes a monitor of information and primarily provides negative performance feedback to the employee. The employee is constrained in his/her ability to use either job resources or social resources to meet the greater demands resulting from the system controlling the pace of work. It is proposed that these work arrangements provoke stress responses in employees that can result in short-term illness and potentially long-term changes in health status. Information enriched work environments are proposed as an alternative. These new work arrangements could improve job resources and social resources to manage job demands and reduce the potentially damaging stress responses. To provide a frame of reference we focus on the impact of EPM systems on the organizational and job elements involved in provoking individual stress responses. The impact of EPM systems on individual health is described using a psychosocial stress framework. Ergonomics interventions discussed include: participation in the design process; allocation of control and coordination functions between the computer and the employee; development of feedback systems; and work measurement and the development of performance appraisal systems.

Journal Article↗
PubMed1997

Lightweight fuzzy processes in clinical computing.

In spite of advances in computing hardware, many hospitals still have a hard time finding extra capacity in their production clinical information system to run artificial intelligence (AI) modules, for example: to support real-time drug-drug or drug-lab interactions; to track infection trends; to monitor compliance with case specific clinical guidelines; or to monitor/ control biomedical devices like an intelligent ventilator. Historically, adding AI functionality was not a major design concern when a typical clinical system is originally specified. AI technology is usually retrofitted 'on top of the old system' or 'run off line' in tandem with the old system to ensure that the routine work load would still get done (with as little impact from the AI side as possible). To compound the burden on system performance, most institutions have witnessed a long and increasing trend for intramural and extramural reporting, (e.g. the collection of data for a quality-control report in microbiology, or a meta-analysis of a suite of coronary artery bypass grafts techniques, etc.) and these place an ever-growing burden on typical the computer system's performance. We discuss a promising approach to adding extra AI processing power to a heavily-used system based on the notion 'lightweight fuzzy processing (LFP)', that is, fuzzy modules designed from the outset to impose a small computational load. A formal model for a useful subclass of fuzzy systems is defined below and is used as a framework for the automated generation of LFPs. By seeking to reduce the arithmetic complexity of the model (a hand-crafted process) and the data complexity of the model (an automated process), we show how LFPs can be generated for three sample datasets of clinical relevance.

Biopsy, Needle↗
PubMed2026

In silico analysis and comparison of the metabolic capabilities of different organisms by reducing metabolic complexity.

BACKGROUND: Understanding how metabolic capabilities diverge across microbial species is essential for deciphering community function, ecological interactions, and the design of synthetic microbiomes. Despite shared core pathways, microbial phenotypes can differ markedly due to evolutionary adaptations and metabolic specialization. Genome-scale metabolic models (GEMs) provide a systems-level framework to explore these differences; however, their complexity hinders direct comparison. RESULTS: We introduce NIS (Neidhardt-Ingraham-Schaechter), a computational workflow that integrates the redGEM, lumpGEM, and redGEMX algorithms to systematically reduce genome-scale models into biologically interpretable modules. This approach enables direct, quantitative comparison of fueling pathways, biomass biosynthetic routes, and environmental exchange processes while retaining essential metabolic information. We first demonstrate the utility of NIS by analyzing Escherichia coli and Saccharomyces cerevisiae, which revealed both conserved and divergent strategies in central metabolism, biosynthetic cost, and substrate utilization. We then applied NIS to the core honeybee gut microbiome, uncovering distinct metabolic traits, functional redundancy, and complementarity that help explain auxotrophy, cross-feeding interactions, and microbial coexistence. CONCLUSIONS: NIS provides an automated, scalable, and reproducible framework for dissecting microbial metabolic networks beyond gene content or taxonomy. By linking metabolism to ecological function, NIS offers new opportunities to interpret microbial community dynamics and to support the rational design of microbiomes in health, agriculture, and environmental applications. Video Abstract.

Metabolic Networks and Pathways↗