Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “parallel evolution”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 991 records · Page 55Linked to original sources
PubMed2000

Free radical production and changes in superoxide dismutases associated with hypoxia/reoxygenation-induced apoptosis of embryonic rat forebrain neurons in culture.

Following hypoxia/reoxygenation (6h/96h), cultured neurons from the embryonic rat forebrain undergo delayed apoptosis. To evaluate the participation of oxidative stress and defense mechanisms, temporal evolution of intraneuronal free radical generation was monitored by flow cytometry using dihydrorhodamine 123, in parallel with the study of transcriptional, translational, and activity changes of the detoxifying enzymes Cu/Zn-SOD and Mn-SOD. Two distinct peaks of radical generation were depicted, at the time of reoxygenation (+ 27%) and 48 h later (+ 25%), respectively. Radical production was unaffected by caspase inhibitors YVAD-CHO or DEVD-CHO, which prevented neuronal damage, suggesting that caspase activation is not an upstream initiator of radicals in this model. Cell treatment by vitamin E (100 microM) displayed significant neuroprotection, whereas the superoxide generating system xanthine/xanthine oxidase induced apoptosis. Transcript and protein levels of both SODs were reduced 1 h after the onset of hypoxia, but activities were transiently stimulated. Reoxygenation was associated with an increased expression (139%), but a decreased activity (21%) of the inducible Mn-SOD, whereas Cu/Zn-SOD protein and activity were low and progressively increased until 48 h post-hypoxia, when the second rise in radicals occurred. In spite of a temporal regulation of SODs, which parallels radical formation, oxidative stress might account for neurotoxicity induced by hypoxia.

Aerobiosis↗
PubMed2005

Diffuse-reflection boundary conditions for a thermal lattice Boltzmann model in two dimensions: evidence of temperature jump and slip velocity in microchannels.

We discuss the implementation of diffuse reflection boundary conditions in a thermal lattice Boltzmann model for which the upwind finite difference scheme is used to solve the set of evolution equations recovered after discretization of the velocity space. Simulation of heat transport between two parallel walls at rest shows evidence of temperature jumps at the walls that increase with Knudsen number. When the walls move in opposite directions with speeds +/- u(W), fluid velocity slip is observed at the walls, together with temperature jumps.

Journal Article↗
PubMed2000

From massively parallel algorithms and fluctuating time horizons to nonequilibrium surface growth

We study the asymptotic scaling properties of a massively parallel algorithm for discrete-event simulations where the discrete events are Poisson arrivals. The evolution of the simulated time horizon is analogous to a nonequilibrium surface. Monte Carlo simulations and a coarse-grained approximation indicate that the macroscopic landscape in the steady state is governed by the Edwards-Wilkinson Hamiltonian. Since the efficiency of the algorithm corresponds to the density of local minima in the associated surface, our results imply that the algorithm is asymptotically scalable.

Journal Article↗
PubMed1972

Photosynthetic properties of permaplasts of anacystis.

A treatment procedure using lysozyme and ethylenediaminetetracetic acid gave intact but permeable cells (permeaplasts) of Anacystis nidulans. Rates of electron transport from water to carbon dioxide, ferricyanide, 2,6-dichlorophenol indophenol, benzoquinone, and methyl viologen, and from reduced indophenol to methyl viologen were measured as a function of treatment time. Rates of oxygen evolution in complete photosynthesis and electron flow from water to methyl viologen showed rapid and parallel decline with treatment time. Electron flow from water to ferricyanide and from reduced indophenol to methyl viologen increased during the first half hour of treatment (phase 1) to 60 to 80% of the original photosynthetic rate. Longer treatment (phase 2) resulted in decreased rate of ferricyanide reduction but not in rate of methyl viologen reduction from indophenol. Electron flow from water to quinone was two to three times higher than for complete photosynthesis in intact cells. It remained high during phase 1 and declined during phase 2. Phase 1 permeaplasts apparently retain high activity for photosystems 1 and 2 photoreactions.

Journal Article↗
PubMed2005

T cell repertoire in patients with stable scleroderma.

At onset of systemic sclerosis (SSc), T cells have been found to oligoclonally expand in the skin, presumably in response to auto-antigens, but the T cell repertoire has not been evaluated at a later stage. To determine whether a perpetuating immune response contributes to the pathogenesis of stable SSc, the T cell repertoire was analysed in patients with diffuse (d) or limited (l) SSc, and compared to patients with primary Raynaud's phenomenon (RP) or healthy volunteers (Ctrl). The T cell repertoire (total, CD4 or CD8 sorted blood T cells) was analysed by qualitative and quantitative immunoscope (14 BV families analysed) in 11 untreated dSSc and 11 untreated lSSc, 10 RP and 11 Ctrl. To better detect in vivo activated cells, repertoire analysis was also performed on sorted CD4 T cells after in vitro culture with IL-2. In parallel, 6 skin biopsies from SSc patients were analysed. After 7-8 years of disease evolution, SSc patients did not show detectable clonal T cell expansions in the skin, even after tentative expansion from the biopsy with IL-2. Total T cell, sorted CD4 and CD8 T cell repertoires from the blood of patients with SSc did not show significant perturbation as compared to patients with RP and Ctrl. After IL-2 culture for 7 days, blood CD4 T cells from the patients did not preferentially expand as compared to RP and Ctrl. These findings suggest that antigen-driven immune responses may play a lesser role in established SSc than at disease onset.

CD4-Positive T-Lymphocytes↗
PubMed1980

Characteristics of serotonin receptors in the rat brain.

Two biochemical methods are currently available for studying 5-HT receptors in the central nervous system. The first consists of measuring the specific high affinity binding of 3H-5-HT to synaptic membranes. The other derives from the discovery of an adenylate cyclase which can be activated by 5-HT in brain homogenates. Whereas the specific 3H-5-HT binding is measurable in young as well as in adult rats, the 5-HT-sensitive adenylate cyclase can be quantitatively estimated only during the first three weeks following birth. Later on, the increment of adenylate cyclase activity produced by 5-HT is too low to permit valid measurements, notably in tissues from adult rats. Studies on the effects of various agonists and antagonists demonstrated that the specific binding site characterized by a high affinity for 3H-5-HT (Kd = 1.5 nM) exhibited the expected properties of a 5-HT receptor in brain. Performing chemical lesions on serotoninergic neurons by an intracerebral injection of 5, 7-dihydroxytryptamine or the blockade of central 5-HT receptors by the peripheral administration of methiothepin resulted in a subsequent increase in the number of specific binding sites for 3H-5-HT particularly in the hippocampus (+30 to +45%). In contrast, preliminary attempts to detect any supersensitivity of the 5-HT-sensitive adenylate cyclase after selective raphe lesions were unsuccessful. Indeed, several observations strongly suggested that the high affinity binding site for 3H-5-HT did not correspond to the 5-HT receptor coupled to adenylate cyclase in synaptic membranes: 1) the apparent affinity of the 5-HT-sensitive adenylate cyclase for 5-HT was about 300 times lower (Kd = 0.5 microM) than that of the specific 3H-5-HT binding site; 2)the ontogenic evolutions of 3H-5-HT binding and 5-HT-sensitive adenylate cyclase were not parallel, notably in the hippocampus; 3) they were differently affected by several drugs. For instance, quipazine, a putative 5-HT agonist, effectively displaced 3H-5-HT from its specific binding site (Ki = 0.23 microM) whereas it did not affect 5-HT-sensitive adenylate cyclase. In conclusion, it is likely that the high affinity binding site for 3H-5-HT and the 5-HT-sensitive adenylate cyclase belong to two different postsynaptic 5-HT receptors in the rat brain.

Adenylyl Cyclases↗
PubMed2006

Chronic obstructive pulmonary disease, risk factors, and outcome trials: comparisons with cardiovascular disease.

Chronic obstructive pulmonary disease (COPD) is a major health problem and now ranks fifth in terms of the global burden of disease. Although COPD is a disease that is characterized by progressive respiratory symptoms and functional decline, exacerbations pose the greatest risk for morbidity and early mortality, have a dramatic effect on quality of life, and are the most significant source of health care expenditure. To improve survival and reduce costs, it is critical to develop effective programs designed to reduce the frequency and severity of exacerbations for these patients. With limited health care resources, efficient and effective management of COPD ideally involves identifying and focusing efforts on individuals at particular risk. In the development of an appropriate multimodal strategy, lessons could be learned from the evolution of guidelines and management of cardiovascular disease, in particular heart failure, which has many parallels with COPD in terms of prevalence, prognosis, and impact on patient quality of life. There is a need for large prospective trials in COPD, based on hard clinical outcomes such as death, which, together with physician and patient education, will help to drive improvements in clinical management.

Cardiovascular Diseases↗
PubMedDate not supplied

Chronicle of advocacy to increase AAPI focused objectives in Healthy People 2010: implications for tobacco-related data and research.

OBJECTIVES: The objectives of this chronicle is to illustrate key components of health polocy advocacy in increasing data availability and research for Asian Americans and Pacific Islanders (AAPIs). METHODS: Through the examination of the evolution of AAPI data in Healthy People 2000 to Healthy People 2010, this chronicle cites parallel and convergent advocacy by AAPI health advocates and tobacco advocates with key external factors that resulted in an increase in AAPI data included in Healthy People 2010. FINDINGS: In Healthy People 2000, there were eight objectives focusing on AAPIs. In Healthy People 2010, 98 objectives included some data for AAPIs and 120 objectives provided categorical reasons why AAPI data were not available. In Healthy People 2010, there was only one objective on tobacco use focusing on AAPIs. Healthy People 2010 includes 11 tobacco use objectives with either AAPI data or categorical reasons why the data were not available. Understanding why AAPI data are not available can direct advocacy efforts. CONCLUSIONS: The AAPI data improvements in Healthy People 2010 have provided useful information on data availability and strategy for data development at the national level. At the same time, the limitations of the national data (lack of AAPI ethnic specific data, data collected only in English) calls for more appropriate data collection and research at the local and regional level.

Asian↗
PubMed2005

Molecular diagnosis in lymphoma.

The evolution of our ability to diagnose and classify lymphomas in an increasingly refined manner has paralleled the development of novel technologic approaches, with contemporary practice dependent upon the harnessing of a plethora of data that include microscopic, immunophenotypic, and genetic information. Although each of these components is currently indispensable, there is a purported progressive improvement in biologic objectivity as one maneuvers through these respective technologies. Accordingly, and in particular given the rapid pace at which key insights into lymphoma biology are emerging with microarray and other cutting-edge technologies, the role of molecular genetic testing is assuming even greater relevance. The ability to diagnose and classify lymphomas more accurately, precisely, and rationally by incorporating molecular data ought to lead to the development of more appropriate directed therapies.

Gene Rearrangement↗
PubMedDate not supplied

Classic intrafascial supracervical hysterectomy (CISH): 10-year experience.

OBJECTIVE: We report and review herein our 10-year experience with classic intrafascial supracervical hysterectomy focusing on our long-term experience, evolution of the operative technique, and increased use of this technique. METHOD: We performed a parallel, observational study with retrospective data to evaluate classic intrafascial supracervical hysterectomy, a laparoscopic hysterectomy technique, at Fayette Medical Center, a community hospital in Northwestern Alabama, USA. Patients comprised a consecutive series of 579 over a 10-year period from November 1992 through November 2002. RESULTS: The classic intrafascial supracervical hysterectomy technique, similar to standard supracervical hysterectomy, leaves the cardinal ligament, uterosacral ligament, vascular supply, and innervation to the upper vagina and cervix intact, but unlike supracervical hysterectomy removes the transition zone and endocervical canal. For 579 patients, the average age was 45.4 years (range, 22 to 92), follow-up was 75.3 months (range, 17 to 137), operating room time was 69 minutes (range, 44 to 370), blood loss was 72 mL (range, 10 to 765), length of hospital stay was 23.2 hours (range, 14 hours to 5 days), time to return to work was 13.2 days (range, 3 to 28). Complications include 11 cervical bleedings, 1 uterine artery bleeding, 1 pelvic hematoma, 1 postoperative ileus, and 16 mucoceles of the cervical stump. Three patients were converted from a laparoscopic to an open procedure (0.52%). Long-term follow-up of up to 137 months shows no adverse events thus far. CONCLUSIONS: Classic intrafascial supracervical hysterectomy is a safe procedure with a low short- and long-term complication rate. It has a short recuperation period and high patient satisfaction. It is the procedure of choice when hysterectomy is indicated for benign disease.

Adult↗
PubMed2005

The Hippocratic impact on healing cults: the archaeological evidence in Attica.

In this paper I will examine the nature of the relationship between Hippocratic medical concepts and the practices of healing sanctuaries within Attica. I will consider the evolution of medical practice in a religious context to the time of Hippocratic medicine, the parallel floruit of Hippocratic practice and healing cults, and the relations between religious and rational medicine in their relative contexts: the temple and the city up to the Roman period. We will reassess the nature of the developing relationship between Hippocratic and religious medical practises, with particular focus on the presence of medical doctors within the healing sanctuaries.

Greek World↗
PubMedDate not supplied

[Evolution of the concept of human death over the course of time. I].

In a brief history of the various religions, ideologies, theories about the "afterlife" and burial rituals that have identified peoples in their evolution from tribal to modern society, an attempt is made to identify the mutually interactive parallel concepts of life and death.

Burial↗
PubMed1988

[Liberal medicine and the labor market in health care. What is liberal medicine?].

This article analyses the practice of what is termed "liberal medicine"--which has paralleled developments in how society is organized--and examines its historical and social determinants. The evolution of the term "liberal" over the centuries, to its present meaning of "practicing the profession as a self-employed physician," is discussed. The author continues the analysis by describing the liberal practice of medicine in the context of the terms of trade in the market for health services and professionals, which lead them to become small-businessmen in their profession. Liberal medicine develops when the unrestricted supply and demand for goods and services reaches the point where production and consumption are determined by systematic trade in a free market, without the restrictions and ties of an outdated social order. But legitimacy and controls related to the rules and regulations of the State, and of professional organizations do exist. This field of study will be examined further in future publications by the author, and by others interested in the problems of the labor force in the health sector.

Health Services Needs and Demand↗
PubMed1983

[French Guiana "papillonite" (lepidopterism). Clinical and epidemiological study].

Clinical studies by Dr R. Pradinaud (Cayenne) has given prominence to the symptoms of "papillonite": its primary and secondary cutaneous lesions, their localisation and evolution as well as its accompanying symptoms such as respiratory pathology. Epidemiologic survey shows a parallelism between the occurrence of papillonite and the presence of the moth Hylesia urticans. The urticant apparatus of this moth was studied with the scanning electron microscope. "Arrow" (fléchettes) were found and they more or less resemble the urticant apparatus of Thaumetopoea pityocampa Schiff caterpillar. The mechanism of action has been studied in the animal and in humans. Extracts prepared from the "arrows" have been rested in vivo guinea-pigs (bleu Evans, Liacopoulos et al.). The findings seem to incriminate an histamino-liberation.

Animals↗
PubMed2002

Caring science and the science of unitary human beings: a trans-theoretical discourse for nursing knowledge development.

BACKGROUND: Two dominant discourses in contemporary nursing theory and knowledge development have evolved over the past few decades, in part by unitary science views and caring theories. Rogers' science of unitary human beings (SUHB) represents the unitary directions in nursing. Caring theories and related caring science (CS) scholarship represent the other. These two contemporary initiatives have generated two parallel, often controversial, seemingly separate and unrelated, trees of knowledge for nursing science. AIM: This paper explores the evolution of CS and its intersection with SUHB that have emerged in contemporary nursing literature. We present a case for integration, convergence, and creative synthesis of CS with SUHB. A trans-theoretical, trans-disciplinary context emerges, allowing nursing to sustain its caring ethic and ontology, within a unitary science. METHODS: The authors critique and review the seminal, critical issues that have separated contemporary knowledge developments in CS and SUHB. Foundational issues of CS, and Watson's theory of transpersonal caring science (TCS), as a specific exemplar, are analysed, alongside parallel themes in SUHB. By examining hidden ethical-ontological and paradigmatic commonalities, trans-theoretical themes and connections are explored and revealed between TCS and SUHB. CONCLUSIONS: Through a creative synthesis of TCS and SUHB we explicate a distinct unitary view of human with a relational caring ontology and ethic that informs nursing as well as other sciences. The result: is a trans-theoretical, trans-disciplinary view for nursing knowledge development. Nursing's history has been to examine theoretical differences rather than commonalities. This trans-theoretical position moves nursing toward theoretical integration and creative synthesis, vs. separation, away from the 'Balkanization' of different theories. This initiative still maintains the integrity of different theories, while facilitating and inviting a new discourse for nursing science. The result: Unitary Caring Science that evokes both science and spirit.

Consciousness↗
PubMedDate not supplied

Utilization of PD modalities: evolution.

In the early 1960s, peritoneal dialysis (PD) was introduced as a form of long-term maintenance therapy in patients with end-stage renal disease (ESRD). We have come a long way since. Increasing understanding of peritoneal kinetic behavior, its innovative manipulation to meet patient needs, critical monitoring of clinical outcomes, and parallel development in technology have all contributed to the worldwide success of the therapy over the past four decades. In this article we review the evolution of the various PD modalities in the context of these factors.

Automation↗
PubMed2003

Structure and evolution of cereal genomes.

The cereal species, of central importance to our diet, began to diverge 50-70 million years ago. For the past few thousand years, these species have undergone largely parallel selection regimes associated with domestication and improvement. The rice genome sequence provides a platform for organizing information about diverse cereals, and together with genetic maps and sequence samples from other cereals is yielding new insights into both the shared and the independent dimensions of cereal evolution. New data and population-based approaches are identifying genes that have been involved in cereal improvement. Reduced-representation sequencing promises to accelerate gene discovery in many large-genome cereals, and to better link the under-explored genomes of 'orphan' cereals with state-of-the-art knowledge.

Agriculture↗
PubMed2025

Parallel algorithms for phylogenetic inference under a structured coalescent approximation.

While advances in molecular epidemiology and computational modeling have enhanced our capacity to track pathogen evolution, the accurate reconstruction of spatiotemporal transmission dynamics remains essential for developing epidemic preparedness frameworks and implementing outbreak response measures. Structured coalescent models offer a phylogeographic framework by restricting lineage coalescence events to geographically proximate host populations. Although the Bayesian structured coalescent approximation (BASTA) provides a tractable approach, contemporary phylogeographic analyses involving dozens of geographic localities and hundreds to thousands of viral genomes substantially exceed the computational capacity of existing implementations. The BASTA likelihood scales cubically with deme count and quadratically with sequence count due to matrix exponentiation and pairwise coalescent probability calculations. Here, we introduce a comprehensive algorithmic restructuring of the structured coalescent likelihood that eliminates redundancies, optimizes memory access, and exposes parallelization opportunities. Our approach reorganizes computations along three dimensions: (i) independent calculation of deme-transition probability matrices across time intervals; (ii) simultaneous evaluation of partial likelihood vectors within temporal slices; and (iii) concurrent aggregation of coalescent probabilities. Algorithmic restructuring cuts average coalescent likelihood computation by 7-8 fold, and parallelization further boosts performance to 10-26 fold, enabling joint phylogeographic analyses of dengue virus across 10 South American countries and H5N1 avian influenza across 20 Eurasian regions to finish in a fraction of prior time. This computational efficiency also enables comparison between backward-in-time structured coalescent approximations and forward-in-time phylogeographic methods, revealing that the former provides appropriately conservative posterior estimates, particularly at intermediate phylogenetic depths. We integrate our implementation into the popular BEAST X and BEAGLE software packages, with an accompanying interface in BEAUti X to easily set up the analyses, providing researchers with an accessible and scalable tool for real-time phylogeographic surveillance of rapidly evolving pathogens.

Journal Article↗