scholarly journals Dynamics and Binary (Trans)formation in Globular Clusters

1996 ◽  
Vol 165 ◽  
pp. 377-388
Author(s):  
Piet Hut
Keyword(s):  
Globular Clusters ◽  
Stellar Dynamics ◽  
Diagnostic Tools ◽  
Reaction Products ◽  
Exchange Reactions ◽  
Blue Stragglers ◽  
The Past ◽  
X Ray Binaries ◽  
Triple Star ◽  
Made In

Globular clusters form ideal laboratories for studying the interactions between stellar evolution and stellar dynamics. In the past, highly exceptional systems such as X-ray binaries and later millisecond pulsars have provided us with useful diagnostic tools. However, the fate of the bulk of the more normal stars has remained less clear. At present, rapid progress is being made in our understanding of the distributions of normal stars and primordial binaries, as well as their most abundant reaction products: blue stragglers and binaries that are produced through exchange encounters with other single stars or binaries. The complexity of the network of exchange reactions is illustrated through some specific examples, such as a formation scenario for the hierarchical triple system containing the millisecond pulsar PSR B1620-26 in M4, the first triple star system ever detected in a globular cluster.

scholarly journals X-Ray Binaries in Early Type Galaxies and the Globular Cluster Connection

2004 ◽  
Vol 194 ◽  
pp. 73-74
Author(s):  
T. J. Maccarone ◽  
A Kundu ◽  
S. E. Zepf ◽  
T. H. Puzia
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
Early Type ◽  
X Ray ◽  
X Ray Binaries ◽  
Cluster Age ◽  
Made In

AbstractWe summarize the key observations made in recent observations of X-ray sources in early-type galaxies. Typically about half of the X-ray binaries in early-type galaxies are in globular clusters, they are preferentially found in metal rich globular clusters, and there is no indication that cluster-age is an important parameter. Theoretical challenges are presented by these results.

scholarly journals High Resolution Studies of Compact Binaries in Globular Clusters With HST and ROSAT

1996 ◽  
Vol 174 ◽  
pp. 171-180
Author(s):  
Jonathan E. Grindlay
Keyword(s):  
High Resolution ◽  
Globular Clusters ◽  
Cataclysmic Variables ◽  
Compact Binaries ◽  
Blue Stragglers ◽  
The Past ◽  
Dense Cores ◽  
Large Populations ◽  
High Resolution Images ◽  
Cluster Cores

The studies of compact binaries containing an accreting white dwarf or neutron star in the dense cores of globular clusters have made considerable progress in the past few years as a result of the high resolution images obtained with HST and ROSAT. It is now clear that cluster cores contain a significant population of these systems which must constrain the similarly large populations of millisecond pulsars as well as dynamical histories of clusters. The population of dim x-ray sources appears to be dominated by cataclysmic variables (CVs) formed by tidal capture and not exchange collisions. Our recent HST/FOS spectra of the first CVs in a cluster core, summarized here in more detail, suggest that cluster cores may contain a significant population of magnetic CVs. The required magnetic WDs may arise in spun-up cores of blue stragglers.

scholarly journals Star Cluster Simulations Including Stellar Evolution

2003 ◽  
Vol 208 ◽  
pp. 131-144
Author(s):  
Stephen L. W. McMillan
Keyword(s):  
Stellar Evolution ◽  
Binary Systems ◽  
Stellar Dynamics ◽  
Star Cluster ◽  
The Past ◽  
Large Numbers ◽  
Evolution Dynamics ◽  
Binary Evolution ◽  
First Time ◽  
Made In

The past few years have seen dramatic improvements in the scope and realism of star cluster simulations. Accurate treatments of stellar evolution, coupled with robust descriptions of all phases of binary evolution, have been incorporated self-consistently into several dynamical codes, allowing for the first time detailed study of the interplay between stellar dynamics and stellar physics. The coupling between evolution, dynamics, and the observational appearance of the cluster is particularly strong in young systems and those containing large numbers of primordial binary systems, and important inroads have been made in these areas, particularly in N-body simulations. I discuss some technical aspects of the current generation of N-body integrators, and describe some recent results obtained using these codes.

scholarly journals Pulmonary Embolism: Still a Diagnostic Quandary

1970 ◽  
Vol 7 (1) ◽  
pp. 34-40
Author(s):  
T Islam
Keyword(s):  
Pulmonary Embolism ◽  
Scientific Meeting ◽  
Diagnostic Tools ◽  
The Past ◽  
Key Words Pulmonary Embolism ◽  
Threatening Condition ◽  
Life Threatening ◽  
Diagnostic Modalities ◽  
Future Direction ◽  
Made In

Objectives: The objective was to review the progress made in the diagnosis of pulmonary embolism over the past decade and the future direction of diagnostic modalities. Methods: Research studies, review articles and scientific meeting abstracts published were reviewed. Results: Significant progress has been made in the diagnosis of pulmonary embolism. Strategies have been developed to increase the sensitivity and specificity of the diagnostic tools. Conclusion: With the advances of the technology and better understanding of patho-physiology, offer the hope of improving the medical management of common and potentially life threatening condition like pulmonary embolism. Key words: Pulmonary embolism; diagnostic modalities; progress DOI: http://dx.doi.org/10.3329/jafmc.v7i1.8625 JAFMC Bangladesh. Vol 7, No 1 (June) 2011; 34-40

scholarly journals Observational evidence for origin of stellar exotica in globular clusters

2006 ◽  
Vol 2 (14) ◽  
pp. 440-441
Author(s):  
Franciscus W.M. Verbunt
Keyword(s):  
Neutron Star ◽  
Globular Clusters ◽  
Cataclysmic Variables ◽  
Observational Evidence ◽  
Encounter Rate ◽  
X Ray ◽  
Blue Stragglers ◽  
Direct Collision ◽  
Orbital Periods ◽  
X Ray Binaries

AbstractThe formation of special binaries in a globular cluster is regulated by the total encounter rate γ in the cluster, but their life expectancy by the number of encounters γ that one system experiences. The orbital periods indicate whether a neutron star or white dwarf entered a binary via direct collision, via tidal capture, or via exchange encounter. The numbers of X-ray binaries with a neutron star scales with γ. Magnetically active binaries (including blue stragglers) are formed via evolution of primordial binaries, and their numbers scale with the cluster mass. Cataclysmic variables are formed by stellar encounters or via evolution of a primordial binary in clusters with high and low central density, respectively.

South Asian Developmental Crisis (Review Article)

1973 ◽  
Vol 12 (2) ◽  
pp. 181-188
Author(s):  
Rafiq Ahmad
Keyword(s):  
Second World War ◽  
World War ◽  
The Past ◽  
The Great Depression ◽  
Political Independence ◽  
Integrated Theory ◽  
Pass Through ◽  
Developed World ◽  
Second World ◽  
Made In

Like nations and civilizations, sciences also pass through period of crises when established theories are overthrown by the unpredictable behaviour of events. Economics is passing through such a crisis. The challenge thrown by the Great Depression of early 1930s took a decade before Keynes re-established the supremacy of economics. But this supremacy has again been upset by the crisis of poverty in the vast under-developed world which attained political independence after the Second World War. Poverty had always existed but never before had it been of such concern to economists as during the past twenty five years or so. Economic literature dealing with this problem has piled up but so have the agonies of poverty. No plausible and well-integrated theory of economic development or under-development has emerged so far, though brilliant advances have been made in isolated directions.

Mass Spectrometry Techniques: Principles and Practices for Quantitative Proteomics

2020 ◽  
Vol 21 ◽  
Author(s):  
Rocco J. Rotello ◽  
Timothy D. Veenstra
Keyword(s):  
Mass Spectrometry ◽  
Quantitative Proteomics ◽  
Protein Identification ◽  
Dynamic Nature ◽  
Complete Coverage ◽  
The Past ◽  
Proteome Level ◽  
A Cell ◽  
Quantitative Changes ◽  
Made In

: In the current omics-age of research, major developments have been made in technologies that attempt to survey the entire repertoire of genes, transcripts, proteins, and metabolites present within a cell. While genomics has led to a dramatic increase in our understanding of such things as disease morphology and how organisms respond to medications, it is critical to obtain information at the proteome level since proteins carry out most of the functions within the cell. The primary tool for obtaining proteome-wide information on proteins within the cell is mass spectrometry (MS). While it has historically been associated with the protein identification, developments over the past couple of decades have made MS a robust technology for protein quantitation as well. Identifying quantitative changes in proteomes is complicated by its dynamic nature and the inability of any technique to guarantee complete coverage of every protein within a proteome sample. Fortunately, the combined development of sample preparation and MS methods have made it capable to quantitatively compare many thousands of proteins obtained from cells and organisms.

Evidence-based Assessment

2010 ◽  
pp. 76-98
Author(s):  
John Hunsley ◽  
Eric J. Mash
Keyword(s):  
Decision Making ◽  
Clinical Assessment ◽  
Assessment Process ◽  
Evidence Based ◽  
The Past ◽  
Specific Assessment ◽  
The Many ◽  
Selection Of ◽  
Made In

Evidence-based assessment relies on research and theory to inform the selection of constructs to be assessed for a specific assessment purpose, the methods and measures to be used in the assessment, and the manner in which the assessment process unfolds. An evidence-based approach to clinical assessment necessitates the recognition that, even when evidence-based instruments are used, the assessment process is a decision-making task in which hypotheses must be iteratively formulated and tested. In this chapter, we review (a) the progress that has been made in developing an evidence-based approach to clinical assessment in the past decade and (b) the many challenges that lie ahead if clinical assessment is to be truly evidence-based.

The Role of Histones and Heparin in Sepsis: A Review

2021 ◽  
pp. 088506662199232
Author(s):  
Xiaojuan Zhang ◽  
Xin Li
Keyword(s):  
Septic Shock ◽  
Multiple Organ ◽  
Clinical Settings ◽  
The Past ◽  
Life Saving ◽  
Extracellular Histones ◽  
Sepsis And Septic Shock ◽  
Development And Management ◽  
Made In

Septic shock with multiple organ failure is a devastating situation in clinical settings. Through the past decades, much progress has been made in the management of sepsis and its underlying pathogenesis, but a highly effective therapeutic has not been developed. Recently, macromolecules such as histones have been targeted in the treatment of sepsis. Histones primarily function as chromosomal organizers to pack DNA and regulate its transcription through epigenetic mechanisms. However, a growing body of research has shown that histone family members can also exert cellular toxicity once they relocate from the nucleus into the extracellular space. Heparin, a commonly used anti-coagulant, has been shown to possess life-saving capabilities for septic patients, but the potential interplay between heparin and extracellular histones has not been investigated. In this review, we summarize the pathogenic roles of extracellular histones and the therapeutic roles of heparin in the development and management of sepsis and septic shock.

scholarly journals Morphological Characteristics, Classifications and Difficulties in the Use of Diagnostic Criteria for Serrated Lesions of the Large Intestine

2021 ◽  
Author(s):  
Cesar de Souza Bastos Junior ◽  
Vera Lucia Nunes Pannain ◽  
Adriana Caroli-Bottino
Keyword(s):  
Diagnostic Criteria ◽  
Morphological Characteristics ◽  
World Health ◽  
Diagnostic Tools ◽  
Serrated Adenoma ◽  
The Past ◽  
The World ◽  
Serrated Lesions ◽  
Health Organization

Abstract Introduction Colorectal carcinoma (CRC) is the most common gastrointestinal neoplasm in the world, accounting for 15% of cancer-related deaths. This condition is related to different molecular pathways, among them the recently described serrated pathway, whose characteristic entities, serrated lesions, have undergone important changes in their names and diagnostic criteria in the past thirty years. The multiplicity of denominations and criteria over the last years may be responsible for the low interobserver concordance (IOC) described in the literature. Objectives The present study aims to describe the evolution in classification of serrated lesions, based on the last three publications of the World Health Organization (WHO) and the reproducibility of these criteria by pathologists, based on the evaluation of the IOC. Methods A search was conducted in the PubMed, ResearchGate and Portal Capes databases, with the following terms: sessile serrated lesion; serrated lesions; serrated adenoma; interobserver concordance; and reproducibility. Articles published since 1990 were researched. Results and Discussion The classification of serrated lesions in the past thirty years showed different denominations and diagnostic criteria. The reproducibility and IOC of these criteria in the literature, based on the kappa coefficient, varied in most studies, from very poor to moderate. Conclusions Interobserver concordance and the reproducibility of microscopic criteria may represent a limitation for the diagnosis and appropriate management of these lesions. It is necessary to investigate diagnostic tools to improve the performance of the pathologist's evaluation, for better concordance, and, consequently, adequate diagnosis and treatment.

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