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Critical Time (critical + time)
Selected AbstractsA Critical Time for Practice Change in the Pain Treatment Continuum: We Need to Reconsider the Role of Pumps in the Patient Care AlgorithmPAIN MEDICINE, Issue 7 2010Timothy R. Deer MD No abstract is available for this article. [source] Time and Temperature Profile of Catheter Cryoablation of Right Septal and Free Wall Accessory Pathways in ChildrenJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2008JONATHAN R. KALTMAN M.D. Introduction: The overall acute success with cryoablation for accessory pathways (APs) has been reported to be lower than with radiofrequency ablation. Generally, prior cryomapping (limited to ,30°C) has been used to test for loss of AP conduction and absence of atrioventricular (AV) node impairment. However, the temperature at which loss of AP conduction occurs may be variable. The purpose of this study was to evaluate the time and temperature profile at which loss of AP conduction occurs. Methods and Results: A retrospective study evaluated 25 patients (mean age 13.3 ± 3.6 years) who underwent cryoablation for right-sided APs (22 manifest/3 concealed). Direct cryoablation (,80°C) without cryomapping was performed using a "time to success" strategy. If AP conduction was successfully interrupted within 25 seconds of the onset of cryoablation, the lesion was continued for 240 seconds; otherwise it was terminated and further mapping was performed. Cryoablation was successful in 24/25 (96%) patients. Temperature at loss of AP conduction was ,66.2 ±,16.7°C (range +32 to ,84°C) with conduction block at temperatures lower than ,30°C for all but 3 APs. Critical time to success (interval from cryoadherence to loss of AP conduction) was significantly shorter for permanently successful cryolesions, compared with transiently successful lesions (6.3 ± 4.1 vs. 11.2 ± 2.2 sec; P < 0.001). There were no major complications. Conclusions: Cryothermal energy required for successful ablation may be variable and restricting test applications to ,30°may limit its efficacy. A "time to success" strategy may improve outcome of cryoablation for right-sided APs in children without compromising safety. [source] Temporal events in the intravenous challenge model for experimental Candida albicans infections in female miceMYCOSES, Issue 3 2005Donna M. MacCallum Summary We characterized the intravenous (i.v.) challenge model for disseminated Candida albicans infection in female BALB/c and DBA/2 mice. Clearance of fungi from the bloodstream and appearance of fungi in tissues were measured at intervals after challenge with various doses of C. albicans. The wild-type isolate SC5314 and derived strains CAF2,1 and CAI-4 transformed with CIp10 were of equal virulence in the model. Variability in mouse survival times, kidney fungal burdens and cachexia was lowest when challenge inocula were within the range 104,105 CFU g,1 body weight in BALB/c mice, but brain fungal burdens and outcomes in DBA/2 mice were variable for all inocula tested. Critical times in the development of infections in optimally challenged BALB/c mice were at 5,10 h (bloodstream fully cleared of fungi), 24 h (start of exponential fungal growth in kidneys) and 48 h (50% of blood cultures become positive). Differential involvement of right and left kidneys occurred almost exclusively in mice challenged with <2 × 104 CFU g,1. We conclude that the i.v. challenge model in female BALB/c mice is now sufficiently well characterized to permit more refined experimentation in future virulence studies with C. albicans mutants. [source] Effect of rheological behavior of epoxy during precuring on foamingJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2008Osamu Takiguchi Abstract In this study, the effect of rheological behavior of epoxy during precuring on foaming was investigated. Dynamic time sweep test of epoxy/curing agent (100/1, w/w) was conducted. The viscosities as a function of time showed extremely rapid increase from the order of 102,103 to 106Pa · s at a certain time, followed by slow increase of the viscosities. Dynamic frequency sweep test of precured epoxy with curing agent was conducted at 90°C. The critical gelation time was obtained by using rheological criterion proposed by Winter and Chambon. We found that the slopes of G,(,) and G,(,) decreased with increasing precuring time. Correspondingly, tan , showed a change from negative to positive slope at a critical time. By using the results, the critical gelation time was determined as t = 895,935 s. Samples of epoxy/curing agent/blowing agent (100/1/0.5) were precured for 960,1620 s. And then precured samples were foamed at 230°C for 300 s to decompose chemical blowing agent. The formed bubble size distribution becomes sharp with increase of the precuring time. There are roughly two sizes of bubbles when precured for relatively short time (t < 1080 s) before foaming: large bubbles (>100 ,m) and small ones (,30 ,m). On the other hand, foams precured for long time (t > 1200 s) before foaming, large bubbles disappear, and the average diameter of the bubble becomes small while the porosity is low. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Obesity and Physical Activity in College Women: Implications for Clinical PracticeJOURNAL OF THE AMERICAN ACADEMY OF NURSE PRACTITIONERS, Issue 7 2004APRN-BC, Jacquelyn M. Clement PhD Purpose To investigate the relationships between levels of physical activity, health attitudes and behaviors, and specific health indicators in women attending college. Data Sources A convenience sample of 116 college women, ages 18 to 24 years, participated in this research study at a moderate-sized midwestern university. The data were obtained through self-administered questionnaire; trained technicians collected physiological measurements. Conclusions The young women in this study had, on average, normal body mass indexes (BMIs) and reported activity levels consistent with or greater than the Centers for Disease Control and Prevention/American College of Sports Medicine guidelines. Items used to assign participants into the appropriate stage of the transtheoretical model of change were correlated with participants' perceived personal physical activity levels. Similarly, the participants, whose scores fell in the higher stages of the transtheoretical model, reported greater levels of physical activity; consumption of more fruits, vegetables, and water; and less consumption of high-fat/high-calorie foods. Implications for Practice The years between ages 18 and 24 are a critical time in the lives of young women. During this period, they develop physical activity and nutrition habits that will affect their health across the life span. Because of the sometimes insidious development of major health problems, young women's current health status may not accurately reflect the possible longterm results of negative health habits. Nurse practitioners (NPs) have many opportunities to identify and address major factors that, if unattended, may threaten the life-long health status of women. Health teaching in the areas of physical activity and dietary habits may be useful even in young women who appear to be healthy, are of normal weight, and are physically active.Poor dietary habits, if unattended, may eventually contribute to the development of obesity and related illnesses. [source] Mullite/Alumina Mixtures for Use as Porous Matrices in Oxide Fiber CompositesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2004Hiroki Fujita Weakly bonded particle mixtures of mullite and alumina are assessed as candidate matrixes for use in porous matrix ceramic composites. Conditions for the deflection of a matrix crack at a fiber-matrix interface are used to identify the combinations of modulus and toughness of the fibers and the matrix for which damage-tolerant behavior is expected to occur in the composite. Accordingly, the present study focuses on the modulus and toughness of the particle mixtures, as well as the changes in these properties following aging at elevated temperature comparable to the targeted upper-use temperature for oxide composites. Models based on bonded particle aggregates are presented, assessed, and calibrated. The experimental and modeling results are combined to predict the critical aging times at which damage tolerance is lost because of sintering at the particle junctions and the associated changes in mechanical properties. For an aging temperature of 1200°C, the critical time exceeds 10 000 h for the mullite-rich mixtures. [source] A sequential attribute sampling inspection game for item facilitiesNAVAL RESEARCH LOGISTICS: AN INTERNATIONAL JOURNAL, Issue 6 2001Morton Canty Abstract The routine inspection of facilities storing large numbers of identical items is modeled as a two-person, sequential game. Timely detection of illegal activity is parameterized in terms of a critical time to detection, and equilibria are derived which provide inspection strategies. Necessary conditions for deterrence of illegal behavior are discussed. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 496,505, 2001 [source] The Role of Angiogenic and Wound Repair Factors During CMV-Accelerated Transplant Vascular Sclerosis in Rat Cardiac TransplantsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2008D. N. Streblow Human cytomegalovirus (HCMV) accelerates transplant vascular sclerosis (TVS), a consequence of angiogenesis (AG) and wound repair (WR). While HCMV can be localized to TVS lesions, the low number of infected cells suggests a global effect on target tissues. We used microarray analysis followed by real-time-polymerase chain reaction (RT-PCR) in an RCMV-accelerated TVS rat cardiac transplant model to determine whether CMV activates host WR and AG factors. Dysregulated cellular genes in allografts from RCMV-infected recipients were compared to those from uninfected recipients and native hearts. We demonstrated that RCMV upregulates the genes involved in WR and AG, which was highest during the critical time of TVS acceleration (21,28 days). Using a standard in vitro AG assay, virus and serum-free supernatants collected at 48 h postinfection significantly induced endothelial cell (EC) migration, branching and tubule formation compared to supernatants from mock-infected cells. Supernatants from ultraviolet (UV)-inactivated RCMV-infected cells failed to induce AG, indicating that virus replication is required. Upregulation of WR and AG genes occurs during the critical period of CMV-accelerated TVS. Targeting these genes may prevent this process and improve allograft survival. [source] The rhetoric of popular Orangism, 1650,72HISTORICAL RESEARCH, Issue 196 2004Jill Stern During the period 1650,72, the Dutch Republic was without a stadtholder prince of Orange. This article examines the rhetoric of the supporters of the House of Orange throughout these years in relation to the common people of the Republic. Within this context, it investigates the arguments that Orangists used to justify the restoration of the stadtholderate, and examines how, at critical times, direct action by the commonalty was incited and justified. The article draws on the printed pamphlets of the period as well as on drama, poetry and visual imagery. [source] Chronic sorrow in parents of children with type 1 diabetesJOURNAL OF ADVANCED NURSING, Issue 5 2009Susan Bowes Abstract Title.,Chronic sorrow in parents of children with type 1 diabetes. Aim., This paper reports on a study exploring parents' longer-term experiences of having a child with type 1 diabetes. Background., Parents of children with type 1 diabetes may experience a grief reaction at diagnosis similar to that normally associated with bereavement, but little is known about their long-term emotional adaptation. Chronic sorrow, a sustained but intermittent grief reaction, is identified in adults with diabetes but has not previously been explored in relation to parents. Methodology., In-depth interviews were conducted in 2007 with a convenience sample of 17 parents of children with type 1 diabetes 7,10 years after diagnosis. Data were explored within a theoretical framework of grief, loss, adaptation, and change. Findings., Parents had adapted to the needs of diabetes management but most had not ,come to terms' with the diagnosis. They experienced a resurgence of grief at critical times during their child's development and some, particularly mothers, became upset during their interviews, even though these took place 7,10 years after their child's diagnosis. Mothers elaborated more on their emotions than fathers, but continuing feelings associated with grief, such as anger and guilt, were expressed by both fathers and mothers. Conclusion., Greater understanding of parents' long-term emotional responses and recognition that grief may never resolve in these parents may enable healthcare professionals to provide appropriate and timely support at critical times. [source] Heterogeneous grazing causes local extinction of edible perennial shrubs: a matrix analysisJOURNAL OF APPLIED ECOLOGY, Issue 2 2001L.P. Hunt Summary 1Population modelling and field measurements of births, growth and deaths were used to investigate the long-term change in abundance of Atriplex vesicaria (Chenopodiaceae), a long-lived, palatable, perennial shrub, under sheep grazing. Of particular interest was whether A. vesicaria is at risk of being eliminated throughout grazed paddocks when the recommended practice of continuous grazing at conservative stocking rates is employed. 2Time-invariant matrix population models indicated that the A. vesicaria population was in decline over much of the study paddock, but the rate of decline was greatest nearer to the water point (population growth rate , , 0·8). Time-varying stochastic matrix models projected that the A. vesicaria population would become locally extinct at most sites up to approximately 2200 m from water, occurring first closer to water (within 12,29 years). The population was stable (i.e. , , 1) at sites greater than 2200 m from water over the projection period of 100 years. 3Decreases in adult survival and recruitment made the largest contributions to reductions in the population growth rate. However, there were spatial patterns centred on the water point in the degree to which particular demographic processes contributed to these reductions, because of a grazing gradient and the differential sensitivity of demographic processes to grazing. Thus decreases in recruitment contributed to reductions in the population growth rate at greater distances. Such responses, together with the sensitivity of the population growth rate to these processes, determined the spatial pattern in population growth. 4The results suggest that piospheres (i.e. the zone of impact) continue to expand over many years under set-stocking so that the area around the water point that is devoid of A. vesicaria becomes larger. The process of expansion appears to first involve the inhibition of recruitment, followed by eventual mortality of established shrubs. 5The large contribution of adult survival to the population growth rate in A. vesicaria suggests that minimizing the mortality of established adults should be a priority for management. This is likely to involve resting from grazing at critical times such as during extended dry periods. This may also permit increased levels of recruitment during subsequent moister periods. [source] Quaternary tephra marker beds and their potential for palaeoenvironmental reconstruction on Chatham Island, east of New Zealand, southwest Pacific Ocean,JOURNAL OF QUATERNARY SCIENCE, Issue 7 2010Katherine A. Holt Abstract Tephras provide one of the most reliable methods of time control and synchronisation within Quaternary sequences. We report on the identification of two widespread rhyolitic tephras , the Kawakawa and Rangitawa tephras , preserved in extensive peat deposits on Chatham Island ,900,km east of New Zealand. The tephras, both products of supereruptions from the Taupo Volcanic Zone, occur as pale, fine-ash dominated layers typically 10,150,mm thick. Mineralogically they are dominated by rhyolitic glass, together with subordinate amounts of quartz, feldspar, hypersthene, hornblende, Fe,Ti oxides and zircon. Phlogopite/biotite was identified additionally in Rangitawa Tephra. Ages for each tephra were obtained via mineralogical and major element glass composition-based correlation with well-dated equivalent deposits on mainland New Zealand, and we also obtained a new zircon fission-track age for Rangitawa Tephra (350,±,50,ka) on Chatham Island. Both tephras were erupted at critical times for palaeoenvironmental reconstructions in the New Zealand region: the Kawakawa at ca. 27 cal. ka, near the beginning of the ,extended' LGM early in marine isotope stage (MIS) 2; and the Rangitawa at ca. 350 ka near the end of MIS 10. The time constraints provided by the tephras demonstrate that Chatham Island peats contain long-distance pollen derived from mainland New Zealand, which provides a reliable proxy for identifying glacial,interglacial climate conditions, in this case during the MIS 11,10 and MIS 2,1 cycles. The two tephras thus provide important chronostratigraphic tie-points that facilitate correlation and synchronisation not only across the Quaternary deposits of the Chatham Islands group but also with climatically significant terrestrial and marine records in the wider New Zealand region. Copyright © 2010 John Wiley & Sons, Ltd. [source] | ||||||||||||||||