Home About us Contact
|
Home About us Contact | ||
|
|
||
Critical Part (critical + part)
Selected AbstractsFishing out marine parasites?ECOLOGY LETTERS, Issue 6 2010Impacts of fishing on rates of parasitism in the ocean Ecology Letters (2010) 13: 761,775 Abstract Among anthropogenic effects on the ocean, fishing is one of the most pervasive and extends deepest into the past. Because fishing reduces the density of fish (reducing transmission efficiency of directly transmitted parasites), selectively removes large fish (which tend to carry more parasites than small fish), and reduces food web complexity (reducing transmission efficiency of trophically transmitted parasites), the removal of fish from the world's oceans over the course of hundreds of years may be driving a long-term, global decline in fish parasites. There has been growing recognition in recent years that parasites are a critical part of biodiversity and that their loss could substantially alter ecosystem function. Such a loss may be among the last major ecological effects of industrial fishing to be recognized by scientists. [source] Recognition of HLA-A*0248 in a Chinese donorINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 3 2003K. L. Yang Summary HLA-A*0248, a rare allele originally found in an individual of Filipino background, was detected in a Chinese donor. We confirmed the novel sequence and analysed its serological reaction pattern. The exon 2 sequence of A*0248 was apparently generated in a gene conversion event with an A2 gene, receiving a sequence segment comprising codons 56 to 74 from an A*24 donor gene. Serological typing showed a clear-cut A2 reaction pattern, indicating that the three amino acid positions 62, 65 and 74, are probably not a critical part of the A2 epitope. Our typing experience also demonstrated that different typing technologies often complement each other in fine HLA typing. [source] Termination of Epicardial Left Ventricular Tachycardia by Pacing without Global CaptureJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2005ASEEM D. DESAI M.D. It is generally accepted that the diagnosis of an epicardial origin of ventricular tachycardia (VT) can be made indirectly by observing VT termination during ablation on the epicardial surface of the heart. There is a caveat, however, which is that termination of VT during radiofrequency current application on the epicardial surface could be due to extension of the lesion beyond the epicardium. Therefore, successful ablation of VT using an epicardial approach does not necessarily prove the reentrant circuit is located superficially. We present a case of a 44-year-old man with VT storm who demonstrated successful termination of VT with radiofrequency current application on the epicardial surface of the heart. This site corresponded to a site where pacing during VT resulted in termination of VT without global capture. Isolated mid-diastolic potentials were only seen at this site as well. We hypothesize that the finding of termination of VT by pacing without global capture supports the argument that the site of pacing is a critical part of the VT circuit. [source] Reconceptualizing the core of nurse practitioner education and practiceJOURNAL OF THE AMERICAN ACADEMY OF NURSE PRACTITIONERS, Issue 1 2009BC (Professor), Mary E. Burman PhD Abstract Purpose: The movement to the doctor of nursing practice (DNP) is progressing rapidly with new programs emerging and curricular documents being developed. We argue that the implementation of the DNP is a good move for nursing, provided that we use the opportunity to reconceptualize the core of advanced practice nursing, especially nurse practitioner (NP) practice. Data sources: Theory and research articles from nursing focused on advanced practice nursing, NPs, and doctoral education. Conclusions: The foundation of NP education is currently based essentially on borrowed or shared content in assessment, pharmacology, and pathophysiology. We argue that the heart and soul of nursing is in health promotion, both in healthy persons and in those dealing with chronic illness. Current master's programs do not prepare NPs to assume high-level practice focused on health promotion and disease management using the latest theoretical developments in health behavior change, behavioral sciences, exercise physiology, nutrition, and medical anthropology. Although these are touched upon in most NP programs, they do not represent the core science of NP education and need to be a critical part of any DNP program. Implications for practice: Ultimately, our vision is for NP care to be consistently "different," yet just as essential as physician care, leading to positive outcomes in health promotion and disease management. [source] Vaccination as a Therapeutic Approach to Alzheimer's DiseaseMOUNT SINAI JOURNAL OF MEDICINE: A JOURNAL OF PERSONALIZED AND TRANSLATIONAL MEDICINE, Issue 1 2010Thomas Wisniewski MD Abstract Alzheimer's disease is the most common cause of dementia worldwide. Alzheimer's disease is a member of a broad range of neurodegenerative diseases characterized pathologically by the conformational change of a normal protein into a pathological conformer with a high ,-sheet content that renders it neurotoxic. In the case of Alzheimer's disease, the normal soluble amyloid , peptide is converted into oligomeric/fibrillar amyloid ,. The oligomeric forms of amyloid , have been hypothesized to be the most toxic, whereas fibrillar amyloid , becomes deposited as amyloid plaques and congophilic angiopathy, which both serve as neuropathological markers of the disease. In addition, the accumulation of abnormally phosphorylated tau as soluble toxic oligomers and as neurofibrillary tangles is a critical part of the pathology. Numerous therapeutic interventions are under investigation to prevent and treat Alzheimer's disease. Among the most exciting and advanced of these approaches is vaccination. Immunomodulation is being tried for a range of neurodegenerative disorders, with great success being reported in most model animal trials; however, the much more limited human data have shown more modest clinical success so far, with encephalitis occurring in a minority of patients treated with active immunization. The immunomodulatory approaches for neurodegenerative diseases involve targeting a self-protein, albeit in an abnormal conformation; hence, effective enhanced clearance of the disease-associated conformer has to be balanced with the potential risk of stimulating excessive toxic inflammation within the central nervous system. The design of future immunomodulatory approaches that are more focused is dependent on addressing a number of questions, including when is the best time to start immunization, what are the most appropriate targets for vaccination, and is amyloid central to the pathogenesis of Alzheimer's disease or is it critical to target tau-related pathology also. In this review, we discuss the past experience with vaccination for Alzheimer's disease and the development of possible future strategies that target both amyloid ,,related and tau-related pathologies. Mt Sinai J Med 77:17&–31, 2010. © 2010 Mount Sinai School of Medicine [source] Enigma Variations: An Interpretation of Heidegger's Sein und ZeitRATIO, Issue 2 2002Simon Critchley There are two phrases in Heidegger's Sein und Zeit that provide a clue to what is going on in that book: Dasein ist geworfener Entwurf and Dasein existiert faktisch (Dasein is thrown projection and Dasein exists factically). I begin by trying to show how an interpretation of these phrases can help clarify Heidegger's philosophical claim about what it means to be human. I then try and explain why it is that, in a couple of important passages in Sein und Zeit, Heidegger describes thrown projection as an enigma (ein Rätsel). After considering the meaning and etymology of the word ,enigma', I trace its usage in Sein und Zeit, and try and show how and why the relations between Heidegger's central conceptual pairings , state-of-mind (Befindlichkeit) and understanding (Verstehen), thrownness and projection, facticity and existentiality , are described by Heidegger as enigmatic. My thesis is that at the heart of Sein und Zeit, that is, at the heart of the central claim of the Dasein-analytic as to the temporal character of thrown-projective being-in-the-world, there lies an enigmatic apriori. That is to say, there is something resiliently opaque at the basis of the constitution of Dasein's being-in-the-world which both resists phenomenological description and which, I shall claim, is that in virtue of which the phenomenologist describes. In the more critical part of the paper, I try and show precisely how this notion of the enigmatic apriori changes the basic experience of understanding Sein und Zeit. I explore this in relation to three examples from Division II: death, conscience and temporality. I try and read Heidegger's analyses of each of these concepts against the grain in order to bring into view much more resilient notions of facticity and thrownness that place in doubt the move to existentiality, projection and authenticity. The perspective I develop can be described as originary inauthenticity. As should become evident, such an interpretation of Sein und Zeit is not without political consequences. [source] Sibling loss, guilt and reparation: A case studyTHE INTERNATIONAL JOURNAL OF PSYCHOANALYSIS, Issue 1 2007CHRISTOPHER CHRISTIAN Psychoanalysis has shown that the death of a sibling is likely to have a long-standing impact on the character development of a surviving child. Among common adult manifestations are the identifi cation with the deceased sibling, repetitive self-punitive behaviors, and the development of masochistic trends. In treatment, these patients can become entrenched in a negative therapeutic reaction that compromises the outcome of their analysis. In this paper, the author discusses the analysis of a woman with a history of losses that included the loss of a sibling at an early age. A critical part of the treatment focused on helping this patient overcome a negative therapeutic reaction that emerged as she became aware of hostile and vengeful fantasies, not only as they related to her deceased brother but, more importantly, as they related to her parents. [source] Tracheolaryngeal Complications of Inherited Epidermolysis Bullosa: Cumulative Experience of the National Epidermolysis Bullosa Registry,THE LARYNGOSCOPE, Issue 9 2007Jo-David Fine MD Abstract Objectives/Hypothesis: To accurately determine the frequency with which complications arise in the ears, noses, and throats of patients with inherited epidermolysis bullosa (EB) as well as the cumulative risk of tracheolaryngeal stenosis or stricture. Study Design: Cross-sectional study (3,280 patients) with a nested, randomly sampled longitudinal subcohort (n = 450), representing data collection, stratified by major EB subtype, of the National EB Registry, an epidemiologic project focused on enrolling all EB patients within the continental United States from 1986 to 2002, to permit generalization of findings to the entire American EB population. Methods: Systematic epidemiologic case finding and data collection were performed throughout the continental United States, followed by subclassification of patients by EB subtype. ENT complications were quantified via contingency tables (as frequencies) and lifetable analyses. Frequencies of surgical procedures were also determined. Results: The most important clinical ENT complication in inherited EB was tracheolaryngeal stenosis or stricture, arising during early childhood and primarily within infants and children with junctional EB (JEB) (cumulative risk of 39.8% and 12.8% in Herlitz and non-Herlitz JEB, respectively, by ages 6 and 9). Other uncommon complications included chronic otitis media, chronic otitis externa, and hearing loss. Conclusions: Given the potential risk for sudden airway occlusion and death, meticulous surveillance by a pediatric otolaryngologist is a critical part of the overall management of infants and children with EB, especially those with JEB and two rare subtypes of generalized EB simplex. Elective tracheostomy should be considered in EB infants and children with evidence of airway embarrassment. [source] Steroid-triggered death by autophagyBIOESSAYS, Issue 8 2001Carl S. Thummel Programmed cell death is a critical part of normal development, removing obsolete tissues or cells and sculpting body parts to assume their appropriate form and function. Most programmed cell death occurs by apoptosis of individual cells or autophagy of groups of cells. Although these pathways have distinct morphological characteristics, they also have a number of features in common, suggesting some overlap in their regulation. A recent paper by Lee and Baehrecke provides further support for this proposal.(1) These authors present, for the first time, a genetic analysis of autophagy, using the steroid-triggered metamorphosis of Drosophila as a model system. They demonstrate a remarkable degree of overlap between the control of apoptosis and autophagy as well as a key role for the steroid-inducible gene E93 in directing the autophagic death response. This paper also shows that E93 can direct cell death independently from the known death-inducer genes, defining a novel death pathway in Drosophila. BioEssays 23:677,682, 2001. © 2001 John Wiley & Sons, Inc. [source] A fatigue and creep study in austenitic stainless steel 316L used in exhaust pipes of naval gas turbinesFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 9 2004R. F. MARTINS ABSTRACT Exhaust pipes of naval gas turbines are made of thin wall tubing of stainless steel grade AISI 316L. The tubes are fabricated by butt welding of different sections with longitudinal and circumferential joints. The plate thickness is about 4.0 mm, and the working temperature varies between 600 °C and 400 °C in the critical zones of the pipe, in the lower and central areas, respectively. The loadings in the tube induce high-temperature fatigue and creep-fatigue cracks have nucleated and propagated in the tube near some welded joints. The paper presents FCGR data obtained in CT specimens of used material taken from the pipes and tested at RT, 335, 500 and 600 °C. Preliminary creep data obtained in tension, in thin-sheet specimens (about 4 mm thickness), also taken from the conduct wall and tested at 500, 550 and 600 °C are also given. These results are crucial to perform a fatigue-creep interaction life assessment of the critical parts of the structure in the near future. Finally, the paper presents results of research work to investigate carbide precipitation and formation in virgin thin-sheet specimens subjected to several types of thermal exposures. In some cases, 3,4 d was the time interval between exposures. Grain size measurements were carried out together with microstructural observations in the SEM. The influence of time, temperature and time interval between thermal exposures was assessed comparing the microstructures. [source] Mechanisms of Right Atrial Tachycardia Occurring Late After Surgical Closure of Atrial Septal DefectsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2005ISABELLE MAGNIN-POULL M.D. Introduction: In patients without structural heart disease, the most frequently occurring AT is the common atrial flutter. In patients with repaired congenital heart disease other mechanisms of AT may occur, due to the presence of an atriotomy that can provide a substrate for reentry. The aim of the present study was to identify the mechanisms of atrial tachycardia (AT) occurring late after atrial septum defect (ASD) repair, with the help of a three-dimensional electroanatomical mapping system. Methods and Results: Twenty-two consecutive patients presenting with AT underwent complete electroanatomic mapping (CARTO®, Biosense Webster, Diamond Bar, CA) of spontaneously occurring and inducible right ATs. Complete maps of 26 ATs were obtained. Three tachycardia mechanisms were identified: single-loop macroreentrant atrial tachycardia (MAT) (n = 7), double-loop MAT (n = 18), and focal AT (n = 1). In all MATs, protected isthmuses were identified as the electrophysiological substrate of the arrhythmia, most frequently the cavotricuspid isthmus (CTI) (n = 24), and a gap between the inferior vena cava and a line of double potentials (n = 11). A mean number of 13.5 ± 2.1 radiofrequency applications were delivered to transect these critical parts of the circuit. During a follow-up of 25 ± 16 months the RF ablation was acutely successful in all patients. Thirteen patients (59%) had an early recurrence of MAT and needed an additional ablation procedure. One of those patients needed two additional ablation procedures. Conclusions: Three-dimensional electroanatomic mapping is useful to identify postsurgical AT mechanisms; the CTI isthmus is involved in 92% MAT, and if the right atrial free wall (RAFW) abnormal tissue related to surgical scar is present this substrate contributes to the MAT circuit [source] Characterization of the Electroanatomic Substrate for Monomorphic Ventricular Tachycardia in Patients with Nonischemic CardiomyopathyPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 7 2002HENRY H. HSIA HSIA, H.H., et al.: Characterization of the Electroanatomic Substrate for Monomorphic Ventricular Tachycardia in Patients with Nonischemic Cardiomyopathy. Ventricular arrhythmias are common in the setting of nonischemic cardiomyopathy. The etiology for the cardiomyopathy is frequently not identified and the label of "idiopathic" is applied. Interstitial fibrosis with conduction system involvement and associated left bundle branch block characterizes the disease process in some patients and the mechanism for monomorphic ventricular tachycardia is commonly bundle branch reentry. However, most patients with nonischemic cardiomyopathy have VT due to myocardial reentry and demonstrate marked myocardial fibrosis and electrogram abnormalities. Although patient specific, the overall distribution of electroanatomic abnormalities appears to be equal on the endocardium and epicardium. The extent of electrogram abnormalities appears to parallel arrhythmia presentation and/or inducibility. Patients with sustained uniform morphology VT have the most extensive endocardial and epicardial electrogram abnormalities. Magnetic electroanatomic voltage mapping provides a powerful tool to characterize the location and extent of the arrhythmia substrate. Basal left ventricular myocardial involvement, as indexed by the location of contiguous electrogram abnormalities, is common in patients with sustained VT and left ventricular cardiomyopathy. The relatively equal distribution of electrogram abnormalities on the endocardium and epicardium, and the results of mapping and ablation attempts, suggest that critical parts of the reentrant circuit may be epicardial. Unique features of the electroanatomic substrate associated with cardiomyopathy due to Chagas' disease, sarcoidosis, and arrhythmogenic right ventricular dysplasia are also discussed. [source] | |||||||||||||