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  1. Stress hyperglycemia in pediatric critical illness: the intensive care unit adds to the stress!

    PubMed

    Srinivasan, Vijay

    2012-01-01

    Stress hyperglycemia (SH) commonly occurs during critical illness in children. The historical view that SH is beneficial has been questioned in light of evidence that demonstrates the association of SH with worse outcomes. In addition to intrinsic changes in glucose metabolism and development of insulin resistance, specific intensive care unit (ICU) practices may influence the development of SH during critical illness. Mechanical ventilation, vasoactive infusions, renal replacement therapies, cardiopulmonary bypass and extracorporeal life support, therapeutic hypothermia, prolonged immobility, nutrition support practices, and the use of medications are all known to mediate development of SH in critical illness. Tight glucose control (TGC) to manage SH has emerged as a promising therapy to improve outcomes in critically ill adults, but results have been inconclusive. Large variations in ICU practices across studies likely resulted in inconsistent results. Future studies of TGC need to take into account the impact of commonly used ICU practices and, ideally, standardize protocols in an attempt to improve the accuracy of conclusions from such studies.

  2. Controversies in the management of the critically ill: the role of probiotics.

    PubMed

    Theodorakopoulou, Maria; Perros, Elias; Giamarellos-Bourboulis, Evangelos J; Dimopoulos, George

    2013-06-01

    Probiotics are commercially available, viable, non-pathogenic micro-organisms that, when ingested in sufficient quantities, exert a health benefit to the host derived through modification of the gut flora, local release of antimicrobial factors, maintenance of integrity of the gut barrier, competition for epithelial adherence, prevention of bacterial translocation, and modulation of the local immune response. In critically ill patients, probiotics appear to lead to decreased susceptibility to antibiotic-associated diarrhoea, Clostridium difficile infections, ventilator-associated pneumonia, necrotising enterocolitis, acute severe pancreatitis, sepsis and multiple organ dysfunction syndrome as well as a shortened duration of infections. Current scientific evidence supporting the use of probiotics is not conclusive and is mainly derived from single-centre, not very well designed trials that are limited by many factors including small sample sizes, heterogeneity in the probiotic strains used, effectiveness of the combined strains, optimum dose regimens, frequency and duration of administration, and certainly incomplete knowledge of the mechanism of action of each strain. Probiotics appear to be well tolerated, whilst adverse events are very rare. The most commonly reported adverse events include bacteraemia, fungaemia and sepsis. At present, based on the available evidence and although helpful and relatively safe for certain disease conditions, routine use of probiotics in the critically ill is not recommended. PMID:23664676

  3. Continuous-time adaptive critics.

    PubMed

    Hanselmann, Thomas; Noakes, Lyle; Zaknich, Anthony

    2007-05-01

    A continuous-time formulation of an adaptive critic design (ACD) is investigated. Connections to the discrete case are made, where backpropagation through time (BPTT) and real-time recurrent learning (RTRL) are prevalent. Practical benefits are that this framework fits in well with plant descriptions given by differential equations and that any standard integration routine with adaptive step-size does an adaptive sampling for free. A second-order actor adaptation using Newton's method is established for fast actor convergence for a general plant and critic. Also, a fast critic update for concurrent actor-critic training is introduced to immediately apply necessary adjustments of critic parameters induced by actor updates to keep the Bellman optimality correct to first-order approximation after actor changes. Thus, critic and actor updates may be performed at the same time until some substantial error build up in the Bellman optimality or temporal difference equation, when a traditional critic training needs to be performed and then another interval of concurrent actor-critic training may resume. PMID:17526332

  4. Erik Erikson: critical times, critical theory.

    PubMed

    Douvan, E

    1997-01-01

    The work and legacy of Erik Erikson are described in this brief outline of his career, his theories, and his impact on psychoanalysis, psychology, history, and the broader culture. His conception of the adolescent task-weaving internal tastes, talents, and values together with elements of one's life history and the demands of one's culture into a coherent identity-has had profound effects on developmental psychology and the way in which sophisticated youth construct and describe their lives. His extension of development through adulthood and old age established the field of life course development. His emphasis on the impact of history and culture on development was a critical element in the developing field of ego psychology. Many of his major contributions can be fruitfully understood in the context of his personal history and individual qualities. PMID:9256525

  5. Erik Erikson: critical times, critical theory.

    PubMed

    Douvan, E

    1997-01-01

    The work and legacy of Erik Erikson are described in this brief outline of his career, his theories, and his impact on psychoanalysis, psychology, history, and the broader culture. His conception of the adolescent task-weaving internal tastes, talents, and values together with elements of one's life history and the demands of one's culture into a coherent identity-has had profound effects on developmental psychology and the way in which sophisticated youth construct and describe their lives. His extension of development through adulthood and old age established the field of life course development. His emphasis on the impact of history and culture on development was a critical element in the developing field of ego psychology. Many of his major contributions can be fruitfully understood in the context of his personal history and individual qualities.

  6. Continuous infusion of antibiotics in the critically ill: The new holy grail for beta-lactams and vancomycin?

    PubMed Central

    2012-01-01

    The alarming global rise of antimicrobial resistance combined with the lack of new antimicrobial agents has led to a renewed interest in optimization of our current antibiotics. Continuous infusion (CI) of time-dependent antibiotics has certain theoretical advantages toward efficacy based on pharmacokinetic/pharmacodynamic principles. We reviewed the available clinical studies concerning continuous infusion of beta-lactam antibiotics and vancomycin in critically ill patients. We conclude that CI of beta-lactam antibiotics is not necessarily more advantageous for all patients. Continuous infusion is only likely to have clinical benefits in subpopulations of patients where intermittent infusion is unable to achieve an adequate time above the minimal inhibitory concentration (T > MIC). For example, in patients with infections caused by organisms with elevated MICs, patients with altered pharmacokinetics (such as the critically ill) and possibly also immunocompromised patients. For vancomycin CI can be chosen, not always for better clinical efficacy, but because it is practical, cheaper, associated with less AUC24h (area under the curve >24 h)-variability, and easier to monitor. PMID:22747633

  7. A "Critical" Time for HRD?

    ERIC Educational Resources Information Center

    Sambrook, Sally

    2004-01-01

    Human resource development (HRD) is a concept associated with human resource management, and, by this association, one component of the broader concept of management. Much work has examined management practices from a critical stance and this article provides a brief review. However, HRD is a more recent concept, still emerging and finding space…

  8. Can We Protect the Gut in Critical Illness: The Role of Growth Factors and Other Novel Approaches

    PubMed Central

    Dominguez, Jessica A.; Coopersmith, Craig M.

    2010-01-01

    Synopsis The intestine plays a central role in the pathophysiology of critical illness and is frequently called the “motor” of the systemic inflammatory response. Perturbations to the intestinal barrier can lead to distant organ damage and multiple organ failure. Therefore, identifying ways to preserve intestinal integrity may be of paramount importance. Growth factors and other peptides have emerged as potential tools for modulation of intestinal inflammation and repair due to their roles in cellular proliferation, differentiation, migration, and survival. In this review, we will examine the involvement of growth factors and other peptides in intestinal epithelial repair during critical illness and their potential use as therapeutic targets. PMID:20643306

  9. The use of echocardiography in the critically ill; the role of FADE (Fast Assessment Diagnostic Echocardiography) training.

    PubMed

    Marum, Susan; Price, Susanna

    2011-08-01

    Echocardiography (echo) is a powerful technique that permits direct visualization and assessment of all the cardiac structures and assessment of the patients' haemodynamic status at the bedside. Echo allows detection of valvular disease, evaluation of ventricular function and the pericardium, detection of intracardiac/intrapulmonary shunts, and can be used to calculate flows and relative pressures between the cardiac chambers. This rapid point-of-care haemodynamic evaluation provides information to guide therapeutic interventions, including volume resuscitation, instigation of vasoactive therapy and/or referral for specialist cardiac/surgical intervention. Although there is abundant evidence in the cardiology literature regarding the use of echo, data in the critical care arena is less well defined, but emerging. The use of echo by intensive care doctors is likely to become routine, and therefore training for intensivists in this technique needs to be developed and supported. The Portuguese Working Group on Echocardiography has developed a skill-based program, FADE (Focused Assessment Diagnostic Echocardiography) in order to train clinicians in the use of bedside ultrasound as a diagnostic and monitoring tool for the critically ill.

  10. Time: A Critical Analysis for Children.

    ERIC Educational Resources Information Center

    Shibles, Warren

    One in a series of books intended to help children improve their critical analytical skills, the document examines the concept of time in light of theories of philosophers Ludwig Wittgenstein and John Dewey. The document is presented in three chapters. Chapter one offers a critical analysis of time from the perspective that time is an unknown and…

  11. Natural time analysis of critical phenomena

    PubMed Central

    Varotsos, Panayiotis; Sarlis, Nicholas V.; Skordas, Efthimios S.; Uyeda, Seiya; Kamogawa, Masashi

    2011-01-01

    A quantity exists by which one can identify the approach of a dynamical system to the state of criticality, which is hard to identify otherwise. This quantity is the variance of natural time χ, where and pk is the normalized energy released during the kth event of which the natural time is defined as χk = k/N and N stands for the total number of events. Then we show that κ1 becomes equal to 0.070 at the critical state for a variety of dynamical systems. This holds for criticality models such as 2D Ising and the Bak–Tang–Wiesenfeld sandpile, which is the standard example of self-organized criticality. This condition of κ1 = 0.070 holds for experimental results of critical phenomena such as growth of rice piles, seismic electric signals, and the subsequent seismicity before the associated main shock. PMID:21700886

  12. Bridging Fields at a Critical Time

    ERIC Educational Resources Information Center

    Baggaley, Jon

    2014-01-01

    The launch of the "Journal of Learning for Development" occurs at a critical time for the education and development field. The "massive open online course" concept currently being implemented by Western educators is considered as a potential cost-saver in developing nations also. MOOCs based on reliable pedagogical principles…

  13. Critical time for NSF, NASA funding bills

    NASA Astrophysics Data System (ADS)

    Jones, Richard

    Although the new fiscal year does not start until October, the next few weeks will be critical in determining the amount of money which the National Science Foundation and the National Aeronautics and Space Administration receive. Scientists who want to communicate their views to key representatives and senators about these agencies should do so now.Every year Congress must pass new funding, or appropriations, legislation. Both NSF and NASA funding come under the jurisdiction of the House and Senate appropriations subcommittees for the Veterans Administration, Department of Housing and Urban Development, and Independent Agencies. These two subcommittees have already heard from NSF officials, and will wrap-up official NASA testimony this week. Several days of hearings from public witnesses are also scheduled.

  14. Evaluating a Construction Product: Timing Is Critical.

    ERIC Educational Resources Information Center

    Brooks, Kenneth W.

    1985-01-01

    This author recommends a comprehensive evalution of education construction projects 11 months following their substantial completion, when users have had sufficient time to identify true weaknesses, original intentions have not been forgotten, shortcomings in materials or the construction process will have appeared, and one year warranties have…

  15. The Hobart Time Ball and Time Gun: a Critical Review

    NASA Astrophysics Data System (ADS)

    Kinns, Roger

    2011-07-01

    Discussion at the Royal Society in Hobart in 1865 and acoustic experiments in 1868 led to a combined time ball and time gun service in Hobart from March 1875. Complaints from residents led to relocation of the gun a month later, but it was then fired from Queen's Battery in the Domain for half a century. The drop of the ball at Battery Point was always the master signal; the gun was fired when the ball was seen to drop. During the early years, private citizens in Hobart provided the time reference. From September 1886, an electric telegraph signal from Hobart Observatory was used to provide correct time to the ball operator, but signals were of questionable accuracy. During February 1910, the source of the telegraph signal was changed from Hobart Observatory to Melbourne Observatory, but the service was still unreliable and there was pressure to re-equip Hobart Observatory. Finally, automatic dropping of the time ball by telegraph from Melbourne was introduced in November 1910. The time ball service ended in February 1927. The time gun had probably ceased to operate by the end of 1923, but before that date there were sometimes long gaps in the time gun service, particularly on Sundays.

  16. Critical Media Literacy: Research, Theory, and Practice in "New Times."

    ERIC Educational Resources Information Center

    Alvermann, Donna E.; Hagood, Margaret C.

    2000-01-01

    Reviews literature on critical media literacy, producing a framework for exploring its implications for educators teaching literacy skills in "New Times." The article examines work on critical theory, popular culture, and mass media in various fields, arguing that the present discourse of schooling is unable to support the incorporation of…

  17. Time and Performance on the California Critical Thinking Skills Test.

    ERIC Educational Resources Information Center

    Frisby, Craig L.; Traffanstedt, Bobby K.

    2003-01-01

    Investigates the relationship between total scores on the California Critical Thinking Skills Test (CCTST) and the time taken to complete it. Finds that slower test takers obtained significantly higher scores. Discusses implications of these findings for college instruction. (SG)

  18. Time discounting and time preference in animals: A critical review.

    PubMed

    Hayden, Benjamin Y

    2016-02-01

    Animals are an important model for studies of impulsivity and self-control. Many studies have made use of the intertemporal choice task, which pits small rewards available sooner against larger rewards available later (typically several seconds), repeated over many trials. Preference for the sooner reward is often taken to indicate impulsivity and/or a failure of self-control. This review shows that very little evidence supports this assumption; on the contrary, ostensible discounting behavior may reflect a boundedly rational but not necessarily impulsive reward-maximizing strategy. Specifically, animals may discount weakly, or even adopt a long-term rate-maximizing strategy, but fail to fully incorporate postreward delays into their choices. This failure may reflect learning biases. Consequently, tasks that measure animal discounting may greatly overestimate the true discounting and may be confounded by processes unrelated to time preferences. If so, animals may be much more patient than is widely believed; human and animal intertemporal choices may reflect unrelated mental operations; and the shared hyperbolic shape of the human and animal discount curves, which is used to justify cross-species comparisons, may be coincidental. The discussion concludes with a consideration of alternative ways to measure self-control in animals.

  19. Scheduling time-critical graphics on multiple processors

    NASA Technical Reports Server (NTRS)

    Meyer, Tom W.; Hughes, John F.

    1995-01-01

    This paper describes an algorithm for the scheduling of time-critical rendering and computation tasks on single- and multiple-processor architectures, with minimal pipelining. It was developed to manage scientific visualization scenes consisting of hundreds of objects, each of which can be computed and displayed at thousands of possible resolution levels. The algorithm generates the time-critical schedule using progressive-refinement techniques; it always returns a feasible schedule and, when allowed to run to completion, produces a near-optimal schedule which takes advantage of almost the entire multiple-processor system.

  20. Compressive sampling for time critical microwave imaging applications

    PubMed Central

    O'Halloran, Martin; McGinley, Brian; Conceicao, Raquel C.; Kilmartin, Liam; Jones, Edward; Glavin, Martin

    2014-01-01

    Across all biomedical imaging applications, there is a growing emphasis placed on reducing data acquisition and imaging times. This research explores the use of a technique, known as compressive sampling or compressed sensing (CS), as an efficient technique to minimise the data acquisition time for time critical microwave imaging (MWI) applications. Where a signal exhibits sparsity in the time domain, the proposed CS implementation allows for sub-sampling acquisition in the frequency domain and consequently shorter imaging times, albeit at the expense of a slight degradation in reconstruction quality of the signals as the compression increases. This Letter focuses on ultra wideband (UWB) radar MWI applications where reducing acquisition is of critical importance therefore a slight degradation in reconstruction quality may be acceptable. The analysis demonstrates the effectiveness and suitability of CS with UWB applications. PMID:26609368

  1. Time-critical multirate scheduling using contemporary real-time operating system services

    NASA Technical Reports Server (NTRS)

    Eckhardt, D. E., Jr.

    1983-01-01

    Although real-time operating systems provide many of the task control services necessary to process time-critical applications (i.e., applications with fixed, invariant deadlines), it may still be necessary to provide a scheduling algorithm at a level above the operating system in order to coordinate a set of synchronized, time-critical tasks executing at different cyclic rates. The scheduling requirements for such applications and develops scheduling algorithms using services provided by contemporary real-time operating systems.

  2. Exploring Gigabyte Datasets in Real Time: Architectures, Interfaces and Time-Critical Design

    NASA Technical Reports Server (NTRS)

    Bryson, Steve; Gerald-Yamasaki, Michael (Technical Monitor)

    1998-01-01

    Architectures and Interfaces: The implications of real-time interaction on software architecture design: decoupling of interaction/graphics and computation into asynchronous processes. The performance requirements of graphics and computation for interaction. Time management in such an architecture. Examples of how visualization algorithms must be modified for high performance. Brief survey of interaction techniques and design, including direct manipulation and manipulation via widgets. talk discusses how human factors considerations drove the design and implementation of the virtual wind tunnel. Time-Critical Design: A survey of time-critical techniques for both computation and rendering. Emphasis on the assignment of a time budget to both the overall visualization environment and to each individual visualization technique in the environment. The estimation of the benefit and cost of an individual technique. Examples of the modification of visualization algorithms to allow time-critical control.

  3. Criticality of timing for anti-HIV therapy initiation.

    PubMed

    Castiglione, Filippo; Paci, Paola

    2010-01-01

    The time of initiation of antiretroviral therapy in HIV-1 infected patients has a determinant effect on the viral dynamics. The question is, how far can the therapy be delayed? Is sooner always better? We resort to clinical data and to microsimulations to forecast the dynamics of the viral load at therapy interruption after prolonged antiretroviral treatment. A computational model previously evaluated, produces results that are statistically adherent to clinical data. In addition, it allows a finer grain analysis of the impact of the therapy initiation point to the disease course. We find a swift increase of the viral density as a function of the time of initiation of the therapy measured when the therapy is stopped. In particular there is a critical time delay with respect to the infection instant beyond which the therapy does not affect the viral rebound. Initiation of the treatment is beneficial because it can down-regulate the immune activation, hence limiting viral replication and spread.

  4. Critical Slowing Down in Time-to-Extinction: An Example of Critical Phenomena in Ecology

    NASA Technical Reports Server (NTRS)

    Gandhi, Amar; Levin, Simon; Orszag, Steven

    1998-01-01

    We study a model for two competing species that explicitly accounts for effects due to discreteness, stochasticity and spatial extension of populations. The two species are equally preferred by the environment and do better when surrounded by others of the same species. We observe that the final outcome depends on the initial densities (uniformly distributed in space) of the two species. The observed phase transition is a continuous one and key macroscopic quantities like the correlation length of clusters and the time-to-extinction diverge at a critical point. Away from the critical point, the dynamics can be described by a mean-field approximation. Close to the critical point, however, there is a crossover to power-law behavior because of the gross mismatch between the largest and smallest scales in the system. We have developed a theory based on surface effects, which is in good agreement with the observed behavior. The course-grained reaction-diffusion system obtained from the mean-field dynamics agrees well with the particle system.

  5. The influence of "quiet time" for patients in critical care.

    PubMed

    Maidl, Carolyn A; Leske, Jane S; Garcia, Annette E

    2014-10-01

    The primary aim was to examine the influence of "quiet time" in critical care. A dual-unit, nonrandomized, uncontrolled trial of a quiet time (QT) protocol was completed. A sample of adult patients from the Neurosciences Intensive Care Unit (NICU) and Cardiovascular Intensive Care Unit (CVICU) participated. Environmental stressors were reduced and patient rest promoted prior to QT. One hundred twenty-nine patients participated in 205 QTs. A one-way, repeated measure analysis of covariance (ANCOVA) was calculated comparing Richards-Campbell Sleep Questionnaire scores, pain and anxiety over three consecutive QTs. No significant statistical effect was found. However, patients rated sleep higher and anxiety levels decreased over consecutive QTs. Ninety-three percent of patients reported QT mattered to them. The combined efforts of nursing, medicine, and ancillary staff are necessary to foster periods of uninterrupted rest, thereby optimizing patient care. Further research is needed to determine if successive QTs positively influence patient outcomes. PMID:23847172

  6. Critical Time Intervention: Model Description and Implications for the Significance of Timing in Social Work Interventions

    ERIC Educational Resources Information Center

    Herman, Daniel B.; Mandiberg, James M.

    2010-01-01

    Relatively little attention has been paid to the dimension of time in the design of social work interventions. Critical time intervention (CTI), an empirically supported psychosocial intervention intended to reduce the risk of homelessness by enhancing continuity of support for individuals with severe mental illness (SMI) during the transition…

  7. Critical Probabilities and Convergence Time of Percolation Probabilistic Cellular Automata

    NASA Astrophysics Data System (ADS)

    Taggi, Lorenzo

    2015-05-01

    This paper considers a class of probabilistic cellular automata undergoing a phase transition with an absorbing state. Denoting by the neighbourhood of site , the transition probability is if or otherwise, . For any there exists a non-trivial critical probability that separates a phase with an absorbing state from a fluctuating phase. This paper studies how the neighbourhood affects the value of and provides lower bounds for . Furthermore, by using dynamic renormalization techniques, we prove that the expected convergence time of the processes on a finite space with periodic boundaries grows exponentially (resp. logarithmically) with the system size if (resp. ). This provides a partial answer to an open problem in Toom et al. (Stochastic Cellular Systems: Ergodicity, Memory, Morphogenesis, pp. 1-182. Manchester University Press, Manchester, 1990; Topics in Contemporary Probability and its Applications, pp. 117-157. CRC Press, Boca Raton, 1995).

  8. Critical source times for nutrient loss in agricultural catchment streams

    NASA Astrophysics Data System (ADS)

    Melland, Alice; Shore, Mairead; Mellander, Per-Erik; McDonald, Noeleen; Shortle, Ger; Murphy, Paul; Jordan, Phil

    2014-05-01

    Identifying periods of the year when there is a high risk of incidental nutrient loss from farms via runoff to streams underpins current nutrient management legislation in Europe. This research explored high-temporal resolution nutrient transfer patterns relative to the time that manure and fertiliser are prohibited from being spread (the mandatory spreading 'closed' period) in five Irish agricultural catchments. Catchment nutrient losses during the 12 week closed periods in 2009-10, 2010-11 and 2011-12 were compared with losses during the remainder of the year, and with losses in the two week 'shoulder' periods immediately before and after the closed period. The closed period losses were assumed to be residual from soil nutrient stores and the 'shoulder' periods were considered to also include incidental losses. Nutrient loss was measured at sub-hourly frequency as total phosphorus (P) and total oxidised nitrogen (mostly nitrate-N) fluxes in streamflow. The streamflow fluxes showed that the proportion of the annual nitrate-N loss occurring during the closed periods (33-61%) was high compared with the remainder of the year. Six to ten times more nitrate-N loss occurred in the two weeks after, compared with the two weeks before, the closed period. These two week 'shoulder' period losses were, on average, less than or equal to 2.5 kg nitrate-N/ha and 9% of total annual nitrate-N loss in streamflow. On average, 40-53% of the annual P loss occurred during the closed periods but in a runoff-prone catchment in a year with a wet summer, the closed period was the less risky period. Similar to nitrate-N, two to twenty times more P loss occurred in the two weeks after, compared with the two weeks before, the closed period. These shoulder period losses were, on average, less than or equal to 0.027 kg/ha and 4.2% of total annual P loss in streamflow. The proportion of the shoulder period loss that could be attributed to recently spread nutrients was not known but can be

  9. Scheduling Real-Time Mixed-Criticality Jobs

    NASA Astrophysics Data System (ADS)

    Baruah, Sanjoy K.; Bonifaci, Vincenzo; D'Angelo, Gianlorenzo; Li, Haohan; Marchetti-Spaccamela, Alberto; Megow, Nicole; Stougie, Leen

    Many safety-critical embedded systems are subject to certification requirements; some systems may be required to meet multiple sets of certification requirements, from different certification authorities. Certification requirements in such "mixed-criticality" systems give rise to interesting scheduling problems, that cannot be satisfactorily addressed using techniques from conventional scheduling theory. In this paper, we study a formal model for representing such mixed-criticality workloads. We demonstrate first the intractability of determining whether a system specified in this model can be scheduled to meet all its certification requirements, even for systems subject to two sets of certification requirements. Then we quantify, via the metric of processor speedup factor, the effectiveness of two techniques, reservation-based scheduling and priority-based scheduling, that are widely used in scheduling such mixed-criticality systems, showing that the latter of the two is superior to the former. We also show that the speedup factors are tight for these two techniques.

  10. Critical Adult Education in Canada in the Time of CASAE

    ERIC Educational Resources Information Center

    Plumb, Donovan

    2009-01-01

    From very early in its history, the Canadian Association for the Study of Adult Education (CASAE) has supported a rich tradition of critique. This chapter argues, however, that in important ways, the magnitude and rapidity of social transformations since the late 1970s have largely overwhelmed the critical capacities of Canadian adult educators.…

  11. Accessible high performance computing solutions for near real-time image processing for time critical applications

    NASA Astrophysics Data System (ADS)

    Bielski, Conrad; Lemoine, Guido; Syryczynski, Jacek

    2009-09-01

    High Performance Computing (HPC) hardware solutions such as grid computing and General Processing on a Graphics Processing Unit (GPGPU) are now accessible to users with general computing needs. Grid computing infrastructures in the form of computing clusters or blades are becoming common place and GPGPU solutions that leverage the processing power of the video card are quickly being integrated into personal workstations. Our interest in these HPC technologies stems from the need to produce near real-time maps from a combination of pre- and post-event satellite imagery in support of post-disaster management. Faster processing provides a twofold gain in this situation: 1. critical information can be provided faster and 2. more elaborate automated processing can be performed prior to providing the critical information. In our particular case, we test the use of the PANTEX index which is based on analysis of image textural measures extracted using anisotropic, rotation-invariant GLCM statistics. The use of this index, applied in a moving window, has been shown to successfully identify built-up areas in remotely sensed imagery. Built-up index image masks are important input to the structuring of damage assessment interpretation because they help optimise the workload. The performance of computing the PANTEX workflow is compared on two different HPC hardware architectures: (1) a blade server with 4 blades, each having dual quad-core CPUs and (2) a CUDA enabled GPU workstation. The reference platform is a dual CPU-quad core workstation and the PANTEX workflow total computing time is measured. Furthermore, as part of a qualitative evaluation, the differences in setting up and configuring various hardware solutions and the related software coding effort is presented.

  12. Oral transit time: a critical review of the literature

    PubMed Central

    SOARES, Thais Jacóe; MORAES, Danielle Pedroni; de MEDEIROS, Gisele Chagas; SASSI, Fernanda Chiarion; ZILBERSTEIN, Bruno; de ANDRADE, Claudia Regina Furquim

    2015-01-01

    Introduction Oral transit time is one of the parameters observed during the clinical assessment of the swallowing function. The importance of this parameter is due to its impact on the total duration of a meal, whose consequence can be an unfavorable nutritional prognostic. Objective To document scientific papers that measure oral transit time in healthy subjects. Method The review followed the steps proposed by the Cochrane Handbook. The search was done via the PubMed database through the use of descriptors related to the oral phase of swallowing, as well as to types of food consistency. Results The articles on the theme had different definitions for oral transit time, as well as heterogeneity of tested volumes, age and gender of the participants. The times found varied from 0.35 s to 1.54 s for liquids, from 0.39 s to 1.05 s for pasty foods and from 1 s to 12.8 s for solid foods. Also, regardless of volume or consistency, oral transit time in elderly people is significantly longer than in adults. Conclusion There's no consensus in the literature about oral transit time in healthy subjects. However, this parameter should be valued during the assessment of the swallowing function due to its negative impact on the dynamics of swallowing, which can cause high energy expenditure during feeding. PMID:26176255

  13. Time-Critical Reading Comprehension Tests and Developmental Students.

    ERIC Educational Resources Information Center

    Kerstiens, Gene

    This study investigated the effect of timed testing on developmental students' scores and developed data that might better reveal students' reading and testing behaviors. Three tests were administered to provide six variables, including the Cooperative English Test, Form 1A (Coop 1A); Cooperative English Test, Form 1B (Coop 1B); and Degrees of…

  14. A Critical Analysis of Time Allocation in Psychoeducational Evaluations

    ERIC Educational Resources Information Center

    Taub, Gordon E.; Valentine, Jennifer

    2014-01-01

    This study provides results form a national survey examining school psychologists' allocation of time in psychoeducational evaluations. A total of 177 participants with an average of 13.45 years professional experience in school psychology, representing 39 states, participated in the survey. The results indicate that school psychologists spend the…

  15. Critical comparison between time- and frequency-domain relaxation functions

    NASA Astrophysics Data System (ADS)

    Snyder, Chad R.; Mopsik, Frederick I.

    1999-07-01

    Considerable work has been performed on providing a theoretical basis for the Kohlrausch-Williams-Watts (KWW) and Havriliak-Negami (HN) relaxation functions. Because of this, several papers have examined the ``interconnection'' of these two functions. In this paper, we demonstrate that, with achievable instrumental sensitivity, these two functions are distinguishable. We further address the issue of the ``universal'' limiting power laws and the ability to obtain the exponents associated with them. Finally, the stability and accuracy of our numerical Laplace transform is demonstrated by comparison between functions with known analytical time and frequency solutions. The stability of our algorithm indicates that the method of Alvarez and co-workers [F. Alvarez, A. Alegría, and J. Colmenero, Phys. Rev. B 44, 7306 (1991)] is an unnecessary approximation for converting between the time and frequency domain.

  16. Automatic Verification of Timing Constraints for Safety Critical Space Systems

    NASA Astrophysics Data System (ADS)

    Fernandez, Javier; Parra, Pablo; Sanchez Prieto, Sebastian; Polo, Oscar; Bernat, Guillem

    2015-09-01

    In this paper is presented an automatic process of verification. We focus in the verification of scheduling analysis parameter. This proposal is part of process based on Model Driven Engineering to automate a Verification and Validation process of the software on board of satellites. This process is implemented in a software control unit of the energy particle detector which is payload of Solar Orbiter mission. From the design model is generated a scheduling analysis model and its verification model. The verification as defined as constraints in way of Finite Timed Automatas. When the system is deployed on target the verification evidence is extracted as instrumented points. The constraints are fed with the evidence, if any of the constraints is not satisfied for the on target evidence the scheduling analysis is not valid.

  17. Application of queueing models to multiprogrammed computer systems operating in a time-critical environment

    NASA Technical Reports Server (NTRS)

    Eckhardt, D. E., Jr.

    1979-01-01

    A model of a central processor (CPU) which services background applications in the presence of time critical activity is presented. The CPU is viewed as an M/M/1 queueing system subject to periodic interrupts by deterministic, time critical process. The Laplace transform of the distribution of service times for the background applications is developed. The use of state of the art queueing models for studying the background processing capability of time critical computer systems is discussed and the results of a model validation study which support this application of queueing models are presented.

  18. The stability of the critical scaling against the time-dependent perturbation

    NASA Astrophysics Data System (ADS)

    Park, Heungsik; Park, Hyunggyu

    2004-04-01

    We study the stability of critical scaling against the time-dependent perturbation in the contact process(CP) model. The critical probability of the particle varies asp = p0 + ct-α. we perform the static Monte Carlo simulation using the finite size scaling theory in the steady state. For the α > 1/v∥, the time dependent perturbation is irrelevant, therefore , the critical exponents β/v∥,β/v⊥ have the DP value. For the α = 1/v∥, β/v∥ is DP value but β/v⊥ is varied with perturbation strength c. For the α < 1/v∥, the particle density is decayed with ρ ˜ tαβ in thermodynamic limit. However, for the all case, z have DP value. To study the stability of critical scaling, we introduce the time-dependent perturbation and know that critical scaling function is satisfied in all cases. Numerical simulations confirm our predictions.

  19. Incubation time for sub-critical crack propagation in SiC-SiC composites

    SciTech Connect

    El-Azab, A.; Ghoniem, N.M.

    1995-04-01

    The objective of this work is to investigate the time for sub-critical crack propagation is SiC-SiC composites at high temperatures. The effects of fiber thermal creep on the relaxation of crack bridging tractions in SiC-SiC ceramic matrix composites (CMCs) is considered in the present work, with the objective of studying the time-to propagation of sub-critical matrix cracks in this material at high temperatures. Under the condition of fiber stress relaxation in the bridiging zone, it is found that the crack opening and the stress intensity factor increase with time for sub-critical matrix cracks. The time elapsed before the stress intensity reaches the critical value for crack propagation is calculated as a function of the initial crack length, applied stress and temperature. Stability domains for matrix cracks are defined, which provide guidelines for conducting high-temperature crack propagation experiments.

  20. Methods for Detecting Early Warnings of Critical Transitions in Time Series Illustrated Using Simulated Ecological Data

    PubMed Central

    Dakos, Vasilis; Carpenter, Stephen R.; Brock, William A.; Ellison, Aaron M.; Guttal, Vishwesha; Ives, Anthony R.; Kéfi, Sonia; Livina, Valerie; Seekell, David A.; van Nes, Egbert H.; Scheffer, Marten

    2012-01-01

    Many dynamical systems, including lakes, organisms, ocean circulation patterns, or financial markets, are now thought to have tipping points where critical transitions to a contrasting state can happen. Because critical transitions can occur unexpectedly and are difficult to manage, there is a need for methods that can be used to identify when a critical transition is approaching. Recent theory shows that we can identify the proximity of a system to a critical transition using a variety of so-called ‘early warning signals’, and successful empirical examples suggest a potential for practical applicability. However, while the range of proposed methods for predicting critical transitions is rapidly expanding, opinions on their practical use differ widely, and there is no comparative study that tests the limitations of the different methods to identify approaching critical transitions using time-series data. Here, we summarize a range of currently available early warning methods and apply them to two simulated time series that are typical of systems undergoing a critical transition. In addition to a methodological guide, our work offers a practical toolbox that may be used in a wide range of fields to help detect early warning signals of critical transitions in time series data. PMID:22815897

  1. Developmental critical windows and sensitive periods as three-dimensional constructs in time and space.

    PubMed

    Burggren, Warren W; Mueller, Casey A

    2015-01-01

    A critical window (sensitive period) represents a period during development when an organism's phenotype is responsive to intrinsic or extrinsic (environmental) factors. Such windows represent a form of developmental phenotypic plasticity and result from the interaction between genotype and environment. Critical windows have typically been defined as comprising discrete periods in development with a distinct starting time and end time, as identified by experiments following an on and an off protocol. Yet in reality, periods of responsiveness during development are likely more ambiguous that depicted. Our goal is to extend the concept of the developmental critical window by introducing a three-dimensional construct in which time during development, dose of the stressor applied, and the resultant phenotypic modification can be utilized to more realistically define a critical window. Using the example of survival of the brine shrimp (Artemia franciscana) during exposure to different salinity levels during development, we illustrate that it is not just stressor dose or exposure time but the interaction of these two factors that results in the measured phenotypic change, which itself may vary within a critical window. We additionally discuss a systems approach to critical windows, in which the components of a developing system--whether they be molecular, physiological, or morphological--may show differing responses with respect to time and dose. Thus, the plasticity of each component may contribute to a broader overall system response. PMID:25730265

  2. Fresh Approach for Critically Ill Patients with Time-sensitive Needs.

    PubMed

    2016-07-01

    To meet the needs of critically ill patients with time-sensitive needs, the University of Maryland Medical Center (UMMC) created the Critical Care Resuscitation Unit (CCRU), a six-bed, short-stay ICU designed to accelerate care to resource-heavy patients who require immediate evaluation and treatment. The CCRU is modeled after UMMC's trauma resuscitation unit, but with resources and staff geared toward non-trauma, critically ill patients, many of whom require life-saving care. The unit is largely staffed by emergency providers who have undergone additional training in critical care. In place at UMMC since July 2013, the CCRU has enabled UMMC to accommodate many more incoming critically ill patients than it has in the past. In its first year of operation, critically ill transfer patients increased more than 64%. Investigators also observed reduced hospital length of stay for these patients, and they noted trends toward lower mortality. Before the creation of the CCRU, developers say that care of critically ill patients often was delayed because there was no space available in an appropriate ICU. Patients admitted to the CCRU present with a wide range of complex critical care needs that require immediate attention, such as ruptured blood vessels, aortic dissections, strokes requiring neuro interventional radiologic procedures, and aneurysmal bleeds. Developers have streamlined the transfer process so that appropriate care can commence even before patients arrive in the CCRU. PMID:27439226

  3. Natural time analysis of critical phenomena: The case of pre-fracture electromagnetic emissions

    SciTech Connect

    Potirakis, S. M.; Karadimitrakis, A.; Eftaxias, K.

    2013-06-15

    Criticality of complex systems reveals itself in various ways. One way to monitor a system at critical state is to analyze its observable manifestations using the recently introduced method of natural time. Pre-fracture electromagnetic (EM) emissions, in agreement to laboratory experiments, have been consistently detected in the MHz band prior to significant earthquakes. It has been proposed that these emissions stem from the fracture of the heterogeneous materials surrounding the strong entities (asperities) distributed along the fault, preventing the relative slipping. It has also been proposed that the fracture of heterogeneous material could be described in analogy to the critical phase transitions in statistical physics. In this work, the natural time analysis is for the first time applied to the pre-fracture MHz EM signals revealing their critical nature. Seismicity and pre-fracture EM emissions should be two sides of the same coin concerning the earthquake generation process. Therefore, we also examine the corresponding foreshock seismic activity, as another manifestation of the same complex system at critical state. We conclude that the foreshock seismicity data present criticality features as well.

  4. Critical ischemia time in a model of spinal cord section. A study performed on dogs

    PubMed Central

    Garcia Martinez, David; Rosales Corral, Sergio A.; Flores Soto, Mario E.; Velarde Silva, Gustavo; Portilla de Buen, Eliseo

    2006-01-01

    Vascular changes after acute spinal cord trauma are important factors that predispose quadriplegia, in most cases irreversible. Repair of the spinal blood flow helps the spinal cord recovery. The average time to arrive and perform surgery is 3 h in most cases. It is important to determine the critical ischemia time in order to offer better functional prognosis. A spinal cord section and vascular clamping of the spinal anterior artery at C5–C6 model was used to determine critical ischemia time. The objective was to establish a critical ischemia time in a model of acute spinal cord section. Four groups of dogs were used, anterior approach and vascular clamp of spinal anterior artery with 1, 2, 3, and 4 h of ischemia and posterior hemisection of spinal cord at C5–C6 was performed. Clinical evaluation was made during 12 weeks and morphological evaluation at the end of this period. We obtained a maximal neurological coordination at 23 days average. Two cases showed sequels of right upper limb paresis at 1 and 3 ischemia hours. There was nerve conduction delay of 56% at 3 h of ischemia. Morphological examination showed 25% of damaged area. The VIII and IX Rexed’s laminae were the most affected. The critical ischemia time was 3 h. Dogs with 4 h did not exhibit any recovery. PMID:17024402

  5. Kibble-Zurek mechanism beyond adiabaticity: Finite-time scaling with critical initial slip

    NASA Astrophysics Data System (ADS)

    Huang, Yingyi; Yin, Shuai; Hu, Qijun; Zhong, Fan

    2016-01-01

    The Kibble-Zurek mechanism demands an initial adiabatic stage before an impulse stage to have a frozen correlation length that generates topological defects in a cooling phase transition. Here we study such a driven critical dynamics but with an initial condition that is near the critical point and that is far away from equilibrium. In this case, there is no initial adiabatic stage at all and thus adiabaticity is broken. However, we show that there again exists a finite length scale arising from the driving that divides the evolution into three stages. A relaxation-finite-time-scaling-adiabatic scenario is then proposed in place of the adiabatic-impulse-adiabatic scenario of the original Kibble-Zurek mechanism. A unified scaling theory, which combines finite-time scaling with critical initial slip, is developed to describe the universal behavior and is confirmed with numerical simulations of a two-dimensional classical Ising model.

  6. Critical time delay of the pineal melatonin rhythm in humans due to weak electromagnetic exposure.

    PubMed

    Halgamuge, Malka N

    2013-08-01

    Electromagnetic fields (EMFs) can increase free radicals, activate the stress response and alter enzyme reactions. Intracellular signalling is mediated by free radicals and enzyme kinetics is affected by radical pair recombination rates. The magnetic field component of an external EMF can delay the "recombination rate" of free radical pairs. Magnetic fields thus increase radical life-times in biological systems. Although measured in nanoseconds, this extra time increases the potential to do more damage. Melatonin regulates the body's sleep-wake cycle or circadian rhythm. The World Health Organization (WHO) has confirmed that prolonged alterations in sleep patterns suppress the body's ability to make melatonin. Considerable cancer rates have been attributed to the reduction of melatonin production as a result of jet lag and night shift work. In this study, changes in circadian rhythm and melatonin concentration are observed due to the external perturbation of chemical reaction rates. We further analyze the pineal melatonin rhythm and investigate the critical time delay or maturation time of radical pair recombination rates, exploring the impact of the mRNA degradation rate on the critical time delay. The results show that significant melatonin interruption and changes to the circadian rhythm occur due to the perturbation of chemical reaction rates, as also reported in previous studies. The results also show the influence of the mRNA degradation rate on the circadian rhythm's critical time delay or maturation time. The results support the hypothesis that exposure to weak EMFs via melatonin disruption can adversely affect human health.

  7. Identifying the Critical Time Period for Information Extraction when Recognizing Sequences of Play

    ERIC Educational Resources Information Center

    North, Jamie S.; Williams, A. Mark

    2008-01-01

    The authors attempted to determine the critical time period for information extraction when recognizing play sequences in soccer. Although efforts have been made to identify the perceptual information underpinning such decisions, no researchers have attempted to determine "when" this information may be extracted from the display. The authors…

  8. Pedagogy in Catastrophic Times: Giroux and the Tasks of Critical Public Intellectuals

    ERIC Educational Resources Information Center

    Morris, Doug

    2012-01-01

    This article reflects on Henry Giroux's work as a critical public intellectual and the important role his work plays in fostering educated hope and insurgent possibilities during our present times of daily and longer term catastrophes. In addition to attempting to capture the experience of what it means and how it feels to read Giroux along with…

  9. Burst wait time simulation of CALIBAN reactor at delayed super-critical state

    SciTech Connect

    Humbert, P.; Authier, N.; Richard, B.; Grivot, P.; Casoli, P.

    2012-07-01

    In the past, the super prompt critical wait time probability distribution was measured on CALIBAN fast burst reactor [4]. Afterwards, these experiments were simulated with a very good agreement by solving the non-extinction probability equation [5]. Recently, the burst wait time probability distribution has been measured at CEA-Valduc on CALIBAN at different delayed super-critical states [6]. However, in the delayed super-critical case the non-extinction probability does not give access to the wait time distribution. In this case it is necessary to compute the time dependent evolution of the full neutron count number probability distribution. In this paper we present the point model deterministic method used to calculate the probability distribution of the wait time before a prescribed count level taking into account prompt neutrons and delayed neutron precursors. This method is based on the solution of the time dependent adjoint Kolmogorov master equations for the number of detections using the generating function methodology [8,9,10] and inverse discrete Fourier transforms. The obtained results are then compared to the measurements and Monte-Carlo calculations based on the algorithm presented in [7]. (authors)

  10. Critical capacity, travel time delays and travel time distribution of rapid mass transit systems

    NASA Astrophysics Data System (ADS)

    Legara, Erika Fille; Monterola, Christopher; Lee, Kee Khoon; Hung, Gih Guang

    2014-07-01

    We set up a mechanistic agent-based model of a rapid mass transit system. Using empirical data from Singapore’s unidentifiable smart fare card, we validate our model by reconstructing actual travel demand and duration of travel statistics. We subsequently use this model to investigate two phenomena that are known to significantly affect the dynamics within the RTS: (1) overloading in trains and (2) overcrowding in the RTS platform. We demonstrate that by varying the loading capacity of trains, a tipping point emerges at which an exponential increase in the duration of travel time delays is observed. We also probe the impact on the rail system dynamics of three types of passenger growth distribution across stations: (i) Dirac delta, (ii) uniform and (iii) geometric, which is reminiscent of the effect of land use on transport. Under the assumption of a fixed loading capacity, we demonstrate the dependence of a given origin-destination (OD) pair on the flow volume of commuters in station platforms.

  11. Cyber-Critical Infrastructure Protection Using Real-Time Payload-Based Anomaly Detection

    NASA Astrophysics Data System (ADS)

    Düssel, Patrick; Gehl, Christian; Laskov, Pavel; Bußer, Jens-Uwe; Störmann, Christof; Kästner, Jan

    With an increasing demand of inter-connectivity and protocol standardization modern cyber-critical infrastructures are exposed to a multitude of serious threats that may give rise to severe damage for life and assets without the implementation of proper safeguards. Thus, we propose a method that is capable to reliably detect unknown, exploit-based attacks on cyber-critical infrastructures carried out over the network. We illustrate the effectiveness of the proposed method by conducting experiments on network traffic that can be found in modern industrial control systems. Moreover, we provide results of a throughput measuring which demonstrate the real-time capabilities of our system.

  12. Spinodals and critical point using short-time dynamics for a simple model of liquid.

    PubMed

    Loscar, Ernesto S; Ferrara, C Gastón; Grigera, Tomás S

    2016-04-01

    We have applied the short-time dynamics method to the gas-liquid transition to detect the supercooled gas instability (gas spinodal) and the superheated liquid instability (liquid spinodal). Using Monte Carlo simulation, we have obtained the two spinodals for a wide range of pressure in sub-critical and critical conditions and estimated the critical temperature and pressure. Our method is faster than previous approaches and allows studying spinodals without needing equilibration of the system in the metastable region. It is thus free of the extrapolation problems present in other methods, and in principle could be applied to systems such as glass-forming liquids, where equilibration is very difficult even far from the spinodal. We have also done molecular dynamics simulations, where we find the method again able to detect the both spinodals. Our results are compared with different previous results in the literature and show a good agreement.

  13. Real-time software use in nuclear materials handling criticality safety control

    SciTech Connect

    Huang, S.; Lappa, D.; Chiao, T.; Parrish, C.; Carlson, R.; Lewis, J.; Shikany, D.; Woo, H.

    1997-06-01

    This paper addresses the use of real-time software to assist handlers of fissionable nuclear material. We focus specifically on the issue of workstation mass limits, and the need for handlers to be aware of, and check against, those mass limits during material transfers. Here ``mass limits`` generally refer to criticality safety mass limits; however, in some instances, workstation mass limits for some materials may be governed by considerations other than criticality, e.g., fire or release consequence limitation. As a case study, we provide a simplified reliability comparison of the use of a manual two handler system with a software-assisted two handler system. We identify the interface points between software and handlers that are relevant to criticality safety.

  14. Space time filling branes in non-critical (super) string theories

    NASA Astrophysics Data System (ADS)

    Lugo, Adrián R.; Sturla, Mauricio B.

    2008-03-01

    We consider solutions of (super) gravities associated to non-critical (super) string theories in arbitrary space-time dimension D=p+3, that describe generically non-extremal black p-branes charged under NSNS or RR gauge fields, embedded in some non-critical vacuum. In the case of vacuum (uncharged) backgrounds, we solve completely the problem obtaining all the possible solutions, that consist of the (p+1)-dimensional Minkowski space-times a linear dilaton times an S, and a three parameter family of solutions that includes (p+1)-dimensional Minkowski space-times the cigar, and its T-dual (p+1)-dimensional Minkowski space-times the trumpet. For NSNS charged solutions, we also solve in closed form the problem, obtaining several families of solutions, that include in particular the fundamental non-critical string solution embedded in the cigar vacuum, recently found in [A.R. Lugo, M.B. Sturla, Phys. Lett. B 637 (2006) 338, hep-th/0604202], a solution that we interpret as a fundamental non-critical string embedded in the linear dilaton vacuum, and a two-parameter family of regular curvature solutions asymptotic to AdS×S. In the case of RR charged D p-branes solutions, an ansatz allows us to find a non-conformal, constant curvature, asymptotically AdS space, T-dual to AdS, together with a two-parameter family of solutions that includes the non-conformal, AdS black hole like solution associated with the earlier space. The solutions obtained by T-duality are Einstein spaces consisting of a two-parameter family of conformal, constant dilaton solutions, that include, in particular, the AdS black hole of [S. Kuperstein, J. Sonnenschein, JHEP 0407 (2004) 049, hep-th/0403254]. We speculate about the possible applications of some of them in the framework of the gauge-gravity correspondence.

  15. Self-organized criticality, long-time correlations, and the standard transport paradigm

    SciTech Connect

    Krommes, J.A.

    2000-02-11

    Some aspects of low-frequency, long-wavelength fluctuations are considered. A stochastic model is used to show that power-law time correlations need not arise from self-organized criticality. A formula for the frequency spectrum of uncorrelated, overlapping avalanches is shown to be a special case of the spectral balance equation of renormalized statistical turbulence theory. It is argued that there need be no contradiction between the presence of long-time correlations and the existence of local transport coefficients.

  16. Critical Spaces for Critical Times: Global Conversations in Literacy Research as an Open Professional Development and Practices Resource

    ERIC Educational Resources Information Center

    Albers, Peggy; Cho, A. Ram; Shin, Ji Hye; Pang, Myoung Eun; Angay-Crowder, Tuba; Jung, Jin Kyeong; Pace, Christi L.; Sena, Mandi; Turnbull, Sarah

    2015-01-01

    This paper reflects an OER (Open Educational Resources) critical literacy project, Global Conversations in Literacy Research (GCLR), (www.globalconversationsinliteracy.wordpress.com), now in its fourth year. GCLR annually hosts seven web seminars presented by internationally recognized literacy and education scholars. We outline key dimensions of…

  17. Influence of time-dependent factors in the evaluation of critical infrastructure protection measures.

    SciTech Connect

    Buehring, W. A.; Samsa, M. E.; Decision and Information Sciences

    2008-03-28

    The examination of which protective measures are the most appropriate to be implemented in order to prevent, protect against, respond to, and recover from attacks on critical infrastructures and key resources typically involves a comparison of the consequences that could occur when the protective measure is implemented to those that could occur when it is not. This report describes a framework for evaluation that provides some additional capabilities for comparing optional protective measures. It illustrates some potentially important time-dependent factors, such as the implementation rate, that affect the relative pros and cons associated with widespread implementation of protective measures. It presents example results from the use of protective measures, such as detectors and pretrained responders, for an illustrative biological incident. Results show that the choice of an alternative measure can depend on whether or not policy and financial support can be maintained for extended periods of time. Choice of a time horizon greatly influences the comparison of alternatives.

  18. Automated implementation of rule-based expert systems with neural networks for time-critical applications

    NASA Technical Reports Server (NTRS)

    Ramamoorthy, P. A.; Huang, Song; Govind, Girish

    1991-01-01

    In fault diagnosis, control and real-time monitoring, both timing and accuracy are critical for operators or machines to reach proper solutions or appropriate actions. Expert systems are becoming more popular in the manufacturing community for dealing with such problems. In recent years, neural networks have revived and their applications have spread to many areas of science and engineering. A method of using neural networks to implement rule-based expert systems for time-critical applications is discussed here. This method can convert a given rule-based system into a neural network with fixed weights and thresholds. The rules governing the translation are presented along with some examples. We also present the results of automated machine implementation of such networks from the given rule-base. This significantly simplifies the translation process to neural network expert systems from conventional rule-based systems. Results comparing the performance of the proposed approach based on neural networks vs. the classical approach are given. The possibility of very large scale integration (VLSI) realization of such neural network expert systems is also discussed.

  19. Time-domain pumping a quantum-critical charge density wave ordered material

    NASA Astrophysics Data System (ADS)

    Matveev, O. P.; Shvaika, A. M.; Devereaux, T. P.; Freericks, J. K.

    2016-09-01

    We determine the exact time-resolved photoemission spectroscopy for a nesting driven charge density wave (described by the spinless Falicov-Kimball model within dynamical mean-field theory). The pump-probe experiment involves two light pulses: the first is an ultrashort intense pump pulse that excites the system into nonequilibrium, and the second is a lower amplitude, higher frequency probe pulse that photoexcites electrons. We examine three different cases: the strongly correlated metal, the quantum-critical charge density wave, and the critical Mott insulator. Our results show that the quantum critical charge density wave has an ultraefficient relaxation channel that allows electrons to be de-excited during the pump pulse, resulting in little net excitation. In contrast, the metal and the Mott insulator show excitations that are closer to what one expects from these systems. In addition, the pump field produces spectral band narrowing, peak sharpening, and a spectral gap reduction, all of which rapidly return to their field free values after the pump is over.

  20. Design oriented identification of critical times in transient response. [due to dynamic loads

    NASA Technical Reports Server (NTRS)

    Haftka, R. T.; Watson, L. T.; Grandhi, R. V.

    1984-01-01

    Two techniques are presented for reducing the computational effort in identifying the critical time points. One approach is an adaptive search technique, well suited for the case where the response is exactly known. The other technique, useful for noisy response, is based on a least-squares spline approximation of the response. The possibility of grouping several closely spaced local peaks to identify a single super peak from each group is also investigated. The computational efficiency of the techniques proposed here is illustrated by two examples.

  1. Reinforcement learning using a continuous time actor-critic framework with spiking neurons.

    PubMed

    Frémaux, Nicolas; Sprekeler, Henning; Gerstner, Wulfram

    2013-04-01

    Animals repeat rewarded behaviors, but the physiological basis of reward-based learning has only been partially elucidated. On one hand, experimental evidence shows that the neuromodulator dopamine carries information about rewards and affects synaptic plasticity. On the other hand, the theory of reinforcement learning provides a framework for reward-based learning. Recent models of reward-modulated spike-timing-dependent plasticity have made first steps towards bridging the gap between the two approaches, but faced two problems. First, reinforcement learning is typically formulated in a discrete framework, ill-adapted to the description of natural situations. Second, biologically plausible models of reward-modulated spike-timing-dependent plasticity require precise calculation of the reward prediction error, yet it remains to be shown how this can be computed by neurons. Here we propose a solution to these problems by extending the continuous temporal difference (TD) learning of Doya (2000) to the case of spiking neurons in an actor-critic network operating in continuous time, and with continuous state and action representations. In our model, the critic learns to predict expected future rewards in real time. Its activity, together with actual rewards, conditions the delivery of a neuromodulatory TD signal to itself and to the actor, which is responsible for action choice. In simulations, we show that such an architecture can solve a Morris water-maze-like navigation task, in a number of trials consistent with reported animal performance. We also use our model to solve the acrobot and the cartpole problems, two complex motor control tasks. Our model provides a plausible way of computing reward prediction error in the brain. Moreover, the analytically derived learning rule is consistent with experimental evidence for dopamine-modulated spike-timing-dependent plasticity. PMID:23592970

  2. Reinforcement learning using a continuous time actor-critic framework with spiking neurons.

    PubMed

    Frémaux, Nicolas; Sprekeler, Henning; Gerstner, Wulfram

    2013-04-01

    Animals repeat rewarded behaviors, but the physiological basis of reward-based learning has only been partially elucidated. On one hand, experimental evidence shows that the neuromodulator dopamine carries information about rewards and affects synaptic plasticity. On the other hand, the theory of reinforcement learning provides a framework for reward-based learning. Recent models of reward-modulated spike-timing-dependent plasticity have made first steps towards bridging the gap between the two approaches, but faced two problems. First, reinforcement learning is typically formulated in a discrete framework, ill-adapted to the description of natural situations. Second, biologically plausible models of reward-modulated spike-timing-dependent plasticity require precise calculation of the reward prediction error, yet it remains to be shown how this can be computed by neurons. Here we propose a solution to these problems by extending the continuous temporal difference (TD) learning of Doya (2000) to the case of spiking neurons in an actor-critic network operating in continuous time, and with continuous state and action representations. In our model, the critic learns to predict expected future rewards in real time. Its activity, together with actual rewards, conditions the delivery of a neuromodulatory TD signal to itself and to the actor, which is responsible for action choice. In simulations, we show that such an architecture can solve a Morris water-maze-like navigation task, in a number of trials consistent with reported animal performance. We also use our model to solve the acrobot and the cartpole problems, two complex motor control tasks. Our model provides a plausible way of computing reward prediction error in the brain. Moreover, the analytically derived learning rule is consistent with experimental evidence for dopamine-modulated spike-timing-dependent plasticity.

  3. Reinforcement Learning Using a Continuous Time Actor-Critic Framework with Spiking Neurons

    PubMed Central

    Frémaux, Nicolas; Sprekeler, Henning; Gerstner, Wulfram

    2013-01-01

    Animals repeat rewarded behaviors, but the physiological basis of reward-based learning has only been partially elucidated. On one hand, experimental evidence shows that the neuromodulator dopamine carries information about rewards and affects synaptic plasticity. On the other hand, the theory of reinforcement learning provides a framework for reward-based learning. Recent models of reward-modulated spike-timing-dependent plasticity have made first steps towards bridging the gap between the two approaches, but faced two problems. First, reinforcement learning is typically formulated in a discrete framework, ill-adapted to the description of natural situations. Second, biologically plausible models of reward-modulated spike-timing-dependent plasticity require precise calculation of the reward prediction error, yet it remains to be shown how this can be computed by neurons. Here we propose a solution to these problems by extending the continuous temporal difference (TD) learning of Doya (2000) to the case of spiking neurons in an actor-critic network operating in continuous time, and with continuous state and action representations. In our model, the critic learns to predict expected future rewards in real time. Its activity, together with actual rewards, conditions the delivery of a neuromodulatory TD signal to itself and to the actor, which is responsible for action choice. In simulations, we show that such an architecture can solve a Morris water-maze-like navigation task, in a number of trials consistent with reported animal performance. We also use our model to solve the acrobot and the cartpole problems, two complex motor control tasks. Our model provides a plausible way of computing reward prediction error in the brain. Moreover, the analytically derived learning rule is consistent with experimental evidence for dopamine-modulated spike-timing-dependent plasticity. PMID:23592970

  4. A Time-Critical Adaptive Approach for Visualizing Natural Scenes on Different Devices

    PubMed Central

    Dong, Tianyang; Liu, Siyuan; Xia, Jiajia; Fan, Jing; Zhang, Ling

    2015-01-01

    To automatically adapt to various hardware and software environments on different devices, this paper presents a time-critical adaptive approach for visualizing natural scenes. In this method, a simplified expression of a tree model is used for different devices. The best rendering scheme is intelligently selected to generate a particular scene by estimating the rendering time of trees based on their visual importance. Therefore, this approach can ensure the reality of natural scenes while maintaining a constant frame rate for their interactive display. To verify its effectiveness and flexibility, this method is applied in different devices, such as a desktop computer, laptop, iPad and smart phone. Applications show that the method proposed in this paper can not only adapt to devices with different computing abilities and system resources very well but can also achieve rather good visual realism and a constant frame rate for natural scenes. PMID:25723177

  5. Critical time step for a bilinear laminated composite Mindlin shell element.

    SciTech Connect

    Hammerand, Daniel Carl

    2004-06-01

    The critical time step needed for explicit time integration of laminated shell finite element models is presented. Each layer is restricted to be orthotropic when viewed from a properly oriented material coordinate system. Mindlin shell theory is used in determining the laminated response that includes the effects of transverse shear. The effects of the membrane-bending coupling matrix from the laminate material model are included. Such a coupling matrix arises even in the case of non-symmetric lay-ups of differing isotropic layers. Single point integration is assumed to be used in determining a uniform strain response from the element. Using a technique based upon one from the literature, reduced eigenvalue problems are established to determine the remaining non-zero frequencies. It is shown that the eigenvalue problem arising from the inplane normal and shear stresses is decoupled from that arising from the transverse shear stresses. A verification example is presented where the exact and approximate results are compared.

  6. Finite Time Extinction for Stochastic Sign Fast Diffusion and Self-Organized Criticality

    NASA Astrophysics Data System (ADS)

    Gess, Benjamin

    2015-04-01

    We prove finite time extinction for stochastic sign fast diffusion equations driven by linear multiplicative space-time noise, corresponding to the Bak-Tang-Wiesenfeld model for self-organized criticality. This solves a problem posed and left open in several works: (Barbu, Methods Appl Sci 36:1726-1733, 2013; Röckner and Wang, J Lond Math Soc (2) 87:545-560, 2013; Barbu et al. J Math Anal Appl 389:147-164, 2012; Barbu and Röckner, Comm Math Phys 311:539-555, 2012; Barbu et al., Comm Math Phys 285:901-923, 2009, C R Math Acad Sci Paris 347(1-2):81-84, 2009). The highly singular-degenerate nature of the drift in interplay with the stochastic perturbation causes the need for new methods in the analysis of mass diffusion, and several new estimates and techniques are introduced.

  7. Exercise training can improve spatial characteristics of time-critical obstacle avoidance in elderly people.

    PubMed

    Weerdesteyn, Vivian; Nienhuis, Bart; Duysens, Jacques

    2008-10-01

    Fall prevention programs have rarely been evaluated by quantitative movement analysis methods. Quantitative movement analyses could provide insight into the mechanisms underlying the effects of training. A treadmill obstacle avoidance task under time pressure has recently been used to evaluate a fall prevention exercise program for community-dwelling elderly people and it showed that participants improved their obstacle avoidance success rates. The mechanism, by which the increased success rates were achieved, however, remained to be determined. Participants were elderly who had fallen at least once in the year prior to participation. They were assigned to either the exercise or the control group. The control group did not receive any specific treatment. The exercise group was administered a five week exercise program, which consisted of exercises on a functionally oriented obstacle course, walking exercises, and practice of fall techniques. Pre- and post-intervention laboratory obstacle avoidance tests were conducted. Three possible determinants of success were investigated, namely avoidance reaction times, the distribution of avoidance strategies, and three spatial parameters (toe distance, foot clearance and heel distance). Analysis yielded significant TimexGroup interactions in heel distances. The exercise group increased heel distance, while the control group did not. Increased heel distance may result in reduced risk of heel contact with the obstacle and, consequently, larger success rates. The remaining parameters showed no effect of training. In conclusion, the training program was effective in improving time-critical obstacle avoidance skills. In every day life, these effects of training may contribute to less obstacle-related fall incidents in elderly. In addition, these findings could indicate that the execution of other time-critical events, like an actual fall, could also be improved by training.

  8. Real-time data system: Incorporating new technology in mission critical environments

    NASA Technical Reports Server (NTRS)

    Muratore, John F.; Heindel, Troy A.

    1990-01-01

    If the Space Station Freedom is to remain viable over its 30-year life span, it must be able to incorporate new information systems technologies. These technologies are necessary to enhance mission effectiveness and to enable new NASA missions, such as supporting the Lunar-Mars Initiative. Hi-definition television (HDTV), neural nets, model-based reasoning, advanced languages, CPU designs, and computer networking standards are areas which have been forecasted to make major strides in the next 30 years. A major challenge to NASA is to bring these technologies online without compromising mission safety. In past programs, NASA managers have been understandably reluctant to rely on new technologies for mission critical activities until they are proven in noncritical areas. NASA must develop strategies to allow inflight confidence building and migration of technologies into the trusted tool base. NASA has successfully met this challenge and developed a winning strategy in the Space Shuttle Mission Control Center. This facility, which is clearly among NASA's most critical, is based on 1970's mainframe architecture. Changes to the mainframe are very expensive due to the extensive testing required to prove that changes do not have unanticipated impact on critical processes. Systematic improvement efforts in this facility have been delayed due to this 'risk to change.' In the real-time data system (RTDS) we have introduced a network of engineering computer workstations which run in parallel to the mainframe system. These workstations are located next to flight controller operating positions in mission control and, in some cases, the display units are mounted in the traditional mainframe consoles. This system incorporates several major improvements over the mainframe consoles including automated fault detection by real-time expert systems and color graphic animated schematics of subsystems driven by real-time telemetry. The workstations have the capability of recording

  9. Actor-critic-based optimal tracking for partially unknown nonlinear discrete-time systems.

    PubMed

    Kiumarsi, Bahare; Lewis, Frank L

    2015-01-01

    This paper presents a partially model-free adaptive optimal control solution to the deterministic nonlinear discrete-time (DT) tracking control problem in the presence of input constraints. The tracking error dynamics and reference trajectory dynamics are first combined to form an augmented system. Then, a new discounted performance function based on the augmented system is presented for the optimal nonlinear tracking problem. In contrast to the standard solution, which finds the feedforward and feedback terms of the control input separately, the minimization of the proposed discounted performance function gives both feedback and feedforward parts of the control input simultaneously. This enables us to encode the input constraints into the optimization problem using a nonquadratic performance function. The DT tracking Bellman equation and tracking Hamilton-Jacobi-Bellman (HJB) are derived. An actor-critic-based reinforcement learning algorithm is used to learn the solution to the tracking HJB equation online without requiring knowledge of the system drift dynamics. That is, two neural networks (NNs), namely, actor NN and critic NN, are tuned online and simultaneously to generate the optimal bounded control policy. A simulation example is given to show the effectiveness of the proposed method. PMID:25312944

  10. Time scales of critical events around the Cretaceous-Paleogene boundary.

    PubMed

    Renne, Paul R; Deino, Alan L; Hilgen, Frederik J; Kuiper, Klaudia F; Mark, Darren F; Mitchell, William S; Morgan, Leah E; Mundil, Roland; Smit, Jan

    2013-02-01

    Mass extinctions manifest in Earth's geologic record were turning points in biotic evolution. We present (40)Ar/(39)Ar data that establish synchrony between the Cretaceous-Paleogene boundary and associated mass extinctions with the Chicxulub bolide impact to within 32,000 years. Perturbation of the atmospheric carbon cycle at the boundary likely lasted less than 5000 years, exhibiting a recovery time scale two to three orders of magnitude shorter than that of the major ocean basins. Low-diversity mammalian fauna in the western Williston Basin persisted for as little as 20,000 years after the impact. The Chicxulub impact likely triggered a state shift of ecosystems already under near-critical stress.

  11. Adaptive automation, trust, and self-confidence in fault management of time-critical tasks.

    PubMed

    Moray, N; Inagaki, T; Itoh, M

    2000-03-01

    An experiment on adaptive automation is described. Reliability of automated fault diagnosis, mode of fault management (manual vs. automated), and fault dynamics affect variables including root mean square error, avoidance of accidents and false shutdowns, subjective trust in the system, and operator self-confidence. Results are discussed in relation to levels of automation, models of trust and self-confidence, and theories of human-machine function allocation. Trust in automation but not self-confidence was strongly affected by automation reliability. Operators controlled a continuous process with difficulty only while performing fault management but could prevent unnecessary shutdowns. Final authority for decisions and action must be allocated to automation in time-critical situations.

  12. Infrared Sensor on Unmanned Aircraft Transmits Time-Critical Wildfire Data

    NASA Technical Reports Server (NTRS)

    Pestana, Mark

    2010-01-01

    Since 2006, NASA fs Dryden Flight Research Center (DFRC) and Ames Research Center have been perfecting and demonstrating a new capability for geolocation of wildfires and the real-time delivery of data to firefighters. Managed for the Western States Fire Mission, the Ames-developed Autonomous Modular Scanner (AMS), mounted beneath a wing of DFRC fs MQ-9 Ikhana remotely piloted aircraft, contains an infrared sensor capable of discriminating temperatures within 0.5 F (approx. = 0.3 C), up to 1,000 F (approx. = 540 C). The AMS operates like a digital camera with specialized filters to detect light energy at visible, infrared, and thermal wavelengths. By placing the AMS aboard unmanned aircraft, one can gather information and imaging for thousands of square miles, and provide critical information about the location, size, and terrain around fires to commanders in the field. In the hands of operational agencies, the benefits of this NASA research and development effort can support nationwide wildfire fighting efforts. The sensor also provides data for post-burn and vegetation regrowth analyses. The MQ-9 Unmanned Aircraft System (UAS), a version of the Predator-B, can operate over long distances, staying aloft for over 24 hours, and controlled via a satellite-linked command and control system. This same link is used to deliver the fire location data directly to fire incident commanders, in less than 10 minutes from the time of overflight. In the current method, similarly equipped short-duration manned aircraft, with limited endurance and range, must land, hand-carry, and process data, and then deliver information to the firefighters, sometimes taking several hours in the process. Meanwhile, many fires would have moved over great distances and changed direction. Speed is critical. The fire incident commanders must assess a very dynamic situation, and task resources such as people, ground equipment, and retardant-dropping aircraft, often in mountainous terrain obscured by

  13. The Efficacy of a Restart Break for Recycling with Optimal Performance Depends Critically on Circadian Timing

    PubMed Central

    Van Dongen, Hans P.A.; Belenky, Gregory; Vila, Bryan J.

    2011-01-01

    deficits. Conclusions: The 34-hour restart break was adequate for maintaining performance in the case of optimal circadian placement of sleep and duty periods (control condition) but was inadequate (and perhaps even detrimental) for maintaining performance in a simulated nighttime duty schedule (experimental condition). Current US transportation hours-of-service regulations mandate time off duty but do not consider the circadian aspects of shift scheduling. Reinforcing a recent trend of applying sleep science to inform policymaking for duty and rest times, our findings indicate that restart provisions in hours-of-service regulations could be improved by taking the circadian timing of the duty schedules into account. Citation: Van Dongen HPA; Belenky G; Vila BJ. The efficacy of a restart break for recycling with optimal performance depends critically on circadian timing. SLEEP 2011;34(7):917-929. PMID:21731142

  14. Analyzing the waiting time pattern for non-critical patients in the emergency department using six sigma approach

    NASA Astrophysics Data System (ADS)

    Majid, Noriza; Mohd Suradi, Nur Riza; Ahmad Sabri, Safura

    2013-04-01

    This study was conducted to examine the waiting time of non-critical patients in the Emergency Department (ED) of Universiti Kebangsaan Malaysia Medical Centre (UKMMC) using the approach of six sigma (6σ). The define phase is completed by obtaining customers' critical to quality in UKMMC using survey. In measure phase, data on patients to the ED of UKMMC in May 2009 were gathered. Subsequently, analysis phase is performed using cause-and-effect diagram to identify root causes of the problems. Finally, improvements are proposed based on the identified problems. Results show that waiting time is critical to quality for health services in the ED.

  15. Data-driven prediction of thresholded time series of rainfall and self-organized criticality models

    NASA Astrophysics Data System (ADS)

    Deluca, Anna; Moloney, Nicholas R.; Corral, Álvaro

    2015-05-01

    We study the occurrence of events, subject to threshold, in a representative self-organized criticality (SOC) sandpile model and in high-resolution rainfall data. The predictability in both systems is analyzed by means of a decision variable sensitive to event clustering, and the quality of the predictions is evaluated by the receiver operating characteristic (ROC) method. In the case of the SOC sandpile model, the scaling of quiet-time distributions with increasing threshold leads to increased predictability of extreme events. A scaling theory allows us to understand all the details of the prediction procedure and to extrapolate the shape of the ROC curves for the most extreme events. For rainfall data, the quiet-time distributions do not scale for high thresholds, which means that the corresponding ROC curves cannot be straightforwardly related to those for lower thresholds. In this way, ROC curves are useful for highlighting differences in predictability of extreme events between toy models and real-world phenomena.

  16. The timing of monozygotic twinning: a criticism of the common model.

    PubMed

    Herranz, Gonzalo

    2015-02-01

    In the dominant model, monozygotic (MZ) twinning is universally accepted as a post-fertilization event resulting from splitting of the embryo along its first 2 weeks of development. The stage at which splitting occurs determines chorionicity and amnionicity. A short history on how the model was built is presented, stressing the role played by some embryologists, in particular George Corner, in its completion and final success. Strikingly, for more than 60 years no deep criticisms have been raised against the model, which, in virtue of its rational and plausible character, enjoys the status of undisputed truth. At close examination, the embryological support of the model shows some important weak points, particularly when dealing with late splitting. In the author's view, the model not only has contributed to 'suspend' our knowledge on the timing of MZ twinning, but seems indefensible and claims to be substituted. That factor could imply relevant consequences for embryology and bioethics. As an alternative to the model, a new theory to explain the timing of MZ twinning is proposed. It is based on two premises. First, MZ twinning would be a fertilization event. In that case, due to an alteration of the zygote-blastomere transition, the first zygotic division, instead of producing two blastomeres, generates twin zygotes. Second, monochorionicity and monoamnionicity would not depend on embryo splitting, but on fusion of membranes. Some support for this theory can be found in recent embryological advances and also in some explanations of old.

  17. Critical care in the surgical global period.

    PubMed

    Painter, Julie R

    2013-03-01

    This article explores the rules and regulations from Current Procedural Terminology (CPT) code set and US Medicare and Medicaid Services (Medicare) regarding multiple physicians reporting critical care services during the global period. The article takes into account the critical care definitions, regulations, documentation requirements, and services each provider can report to Medicare. A clinical scenario based on literature supporting the types of complications and care that might typically be included in the post-operative period for a patient who is surgically treated for a type A aortic dissection was analyzed. It was determined that multiple physicians may provide critical care services to a single patient during the global period. The physician who performed the primary procedure cannot report critical care separately unless documentation supporting use of modifier 25 (significant, separately identifiable services) or 24 (unrelated services) supports that critical care is unrelated to the global period. Other physicians may report critical care services separately if specific criteria are met. To report critical care services to Medicare, the patient's condition must meet the Medicare definition of critical care and the physicians should generally represent different specialties providing different aspects of care to the critically ill or injured patient as defined by Medicare. There should be no overlap in time of services provided by each physician. Each physician's documentation should clearly support medical necessity with the diagnosis demonstrating the critical nature of the patients' illness, the total time spent providing critical care, the critical care service provided, and other contributing factors.

  18. Critical space-time networks and geometric phase transitions from frustrated edge antiferromagnetism.

    PubMed

    Trugenberger, Carlo A

    2015-12-01

    Recently I proposed a simple dynamical network model for discrete space-time that self-organizes as a graph with Hausdorff dimension d(H)=4. The model has a geometric quantum phase transition with disorder parameter (d(H)-d(s)), where d(s) is the spectral dimension of the dynamical graph. Self-organization in this network model is based on a competition between a ferromagnetic Ising model for vertices and an antiferromagnetic Ising model for edges. In this paper I solve a toy version of this model defined on a bipartite graph in the mean-field approximation. I show that the geometric phase transition corresponds exactly to the antiferromagnetic transition for edges, the dimensional disorder parameter of the former being mapped to the staggered magnetization order parameter of the latter. The model has a critical point with long-range correlations between edges, where a continuum random geometry can be defined, exactly as in Kazakov's famed 2D random lattice Ising model but now in any number of dimensions. PMID:26764755

  19. Critical space-time networks and geometric phase transitions from frustrated edge antiferromagnetism

    NASA Astrophysics Data System (ADS)

    Trugenberger, Carlo A.

    2015-12-01

    Recently I proposed a simple dynamical network model for discrete space-time that self-organizes as a graph with Hausdorff dimension dH=4 . The model has a geometric quantum phase transition with disorder parameter (dH-ds) , where ds is the spectral dimension of the dynamical graph. Self-organization in this network model is based on a competition between a ferromagnetic Ising model for vertices and an antiferromagnetic Ising model for edges. In this paper I solve a toy version of this model defined on a bipartite graph in the mean-field approximation. I show that the geometric phase transition corresponds exactly to the antiferromagnetic transition for edges, the dimensional disorder parameter of the former being mapped to the staggered magnetization order parameter of the latter. The model has a critical point with long-range correlations between edges, where a continuum random geometry can be defined, exactly as in Kazakov's famed 2D random lattice Ising model but now in any number of dimensions.

  20. A Critical Time Window for Organismal Interactions in a Pelagic Ecosystem

    PubMed Central

    Benoit-Bird, Kelly J.; McManus, Margaret A.

    2014-01-01

    To measure organismal coherence in a pelagic ecosystem, we used moored sensors to describe the vertical dynamics of each step in the food chain in shelf waters off the west shore of Oahu, Hawaii. Horizontally extensive, intense aggregations of phytoplankton, zooplankton, and micronekton exhibited strong diel patterns in abundance and vertical distribution, resulting in a highly variable potential for interaction amongst trophic levels. Only around dusk did zooplankton layers overlap with phytoplankton layers. Shortly after sunset, micronekton ascended from the deep, aggregating on the island's shelf. Short-lived departures in migration patterns were detected in depth, vertical distribution, density, and total abundance of micronekton when zooplankton layers were present with typical patterns resuming within one hour. Layers of zooplankton began to disappear within 20 minutes of the arrival of micronekton with no layers present after 50 minutes. The effects of zooplankton layers cascaded even further up the food chain, affecting many behaviors of dolphins observed at dusk including their depth, group size, and inter-individual spacing. As a result of these changes in behavior, during a 30-minute window just after dusk, the number of feeding events observed for each dolphin and consequently the feeding time for each individual more than doubled when zooplankton layers were present. Dusk is a critical period for interactions amongst species in this system from phytoplankton to top predators. Our observations that short time windows can drive the structure and function of a complex suite of organisms highlight the importance of explicitly adding a temporal dimension at a scale relevant to individual organisms to our descriptions of heterogeneity in ocean ecosystems. PMID:24844981

  1. Ion channel stochasticity may be critical in determining the reliability and precision of spike timing.

    PubMed

    Schneidman, E; Freedman, B; Segev, I

    1998-10-01

    The firing reliability and precision of an isopotential membrane patch consisting of a realistically large number of ion channels is investigated using a stochastic Hodgkin-Huxley (HH) model. In sharp contrast to the deterministic HH model, the biophysically inspired stochastic model reproduces qualitatively the different reliability and precision characteristics of spike firing in response to DC and fluctuating current input in neocortical neurons, as reported by Mainen & Sejnowski (1995). For DC inputs, spike timing is highly unreliable; the reliability and precision are significantly increased for fluctuating current input. This behavior is critically determined by the relatively small number of excitable channels that are opened near threshold for spike firing rather than by the total number of channels that exist in the membrane patch. Channel fluctuations, together with the inherent bistability in the HH equations, give rise to three additional experimentally observed phenomena: subthreshold oscillations in the membrane voltage for DC input, "spontaneous" spikes for subthreshold inputs, and "missing" spikes for suprathreshold inputs. We suggest that the noise inherent in the operation of ion channels enables neurons to act as "smart" encoders. Slowly varying, uncorrelated inputs are coded with low reliability and accuracy and, hence, the information about such inputs is encoded almost exclusively by the spike rate. On the other hand, correlated presynaptic activity produces sharp fluctuations in the input to the postsynaptic cell, which are then encoded with high reliability and accuracy. In this case, information about the input exists in the exact timing of the spikes. We conclude that channel stochasticity should be considered in realistic models of neurons.

  2. Real time evolution of non-Gaussian cumulants in the QCD critical regime

    SciTech Connect

    Mukherjee, Swagato; Venugopalan, Raju; Yin, Yi

    2015-09-23

    In this study, we derive a coupled set of equations that describe the nonequilibrium evolution of cumulants of critical fluctuations for spacetime trajectories on the crossover side of the QCD phase diagram. In particular, novel expressions are obtained for the nonequilibrium evolution of non-Gaussian skewness and kurtosis cumulants. UBy utilizing a simple model of the spacetime evolution of a heavy-ion collision, we demonstrate that, depending on the relaxation rate of critical fluctuations, skewness and kurtosis can differ significantly in magnitude as well as in sign from equilibrium expectations. Memory effects are important and shown to persist even for trajectories that skirt the edge of the critical regime. We use phenomenologically motivated parametrizations of freeze-out curves and of the beam-energy dependence of the net baryon chemical potential to explore the implications of our model study for the critical-point search in heavy-ion collisions.

  3. Real time evolution of non-Gaussian cumulants in the QCD critical regime

    DOE PAGESBeta

    Mukherjee, Swagato; Venugopalan, Raju; Yin, Yi

    2015-09-23

    In this study, we derive a coupled set of equations that describe the nonequilibrium evolution of cumulants of critical fluctuations for spacetime trajectories on the crossover side of the QCD phase diagram. In particular, novel expressions are obtained for the nonequilibrium evolution of non-Gaussian skewness and kurtosis cumulants. UBy utilizing a simple model of the spacetime evolution of a heavy-ion collision, we demonstrate that, depending on the relaxation rate of critical fluctuations, skewness and kurtosis can differ significantly in magnitude as well as in sign from equilibrium expectations. Memory effects are important and shown to persist even for trajectories thatmore » skirt the edge of the critical regime. We use phenomenologically motivated parametrizations of freeze-out curves and of the beam-energy dependence of the net baryon chemical potential to explore the implications of our model study for the critical-point search in heavy-ion collisions.« less

  4. Time that tells: critical clock-drawing errors for dementia screening

    PubMed Central

    Lessig, Mary C.; Scanlan, James M.; Nazemi, Hamid; Borson, Soo

    2009-01-01

    Background Clock-drawing tests are popular components of dementia screens but no single scoring system has been universally accepted. We sought to identify an optimal subset of clock errors for dementia screening and compare them with three other systems representative of the existing wide variations in approach (Shulman, Mendez, Wolf-Klein), as well as with the CDT system used in the Mini-Cog, which combines clock drawing with delayed recall. Methods The clock drawings of an ethnolinguistically and educationally diverse sample (N = 536) were analyzed for the association of 24 different errors with the presence and severity of dementia defined by independent research criteria. The final sample included 364 subjects with ≥5 years of education, as preliminary examination suggested different error patterns in subjects with 0–4 years of education and inadequate numbers of normal controls for reliable analysis. Results Eleven of 24 errors were significantly associated with dementia in subjects with ≥5 years of education, and six were combined to identify dementia with 88% specificity and 71% sensitivity: inaccurate time setting, no hands, missing numbers, number substitutions or repetitions, or refusal to attempt clock drawing. Time setting was the most prevalent error at all dementia stages, refusal occurred only in moderate and severe dementia; and ethnicity and language of administration had no effect. All critical errors increased in frequency with dementia stage. This simplified scoring system had much better specificity than two other systems (88% vs 39% for Mendez’s system –63% for Shulman’s) and much better sensitivity than Wolf-Klein’s (71% vs 51%). Stepwise logistic regression found the simplified system to be more strongly predictive of dementia than the three other CDT systems of dementia. Substituting the new CDT algorithm for that used in the original CDT Mini-Cog improved the Mini-Cog’s specificity from 89 to 93% with minimal change in

  5. Time-Critical Studies: Rapid response to Transient Dynamic Mid-Ocean Ridge Events

    NASA Astrophysics Data System (ADS)

    Cowen, J. P.; Baker, E. T.; Dziak, R. P.; Lilley, M. M.

    2003-12-01

    The Time-Critical Studies (TCS) Theme of Ridge 2000 focuses on observations of the immediate geochemical and geobiological consequences of magmatic and tectonic events along the global mid-ocean ridge system. To date funding has centered on the Juan de Fuca and Gorda Ridges which are within the range of the U.S. Navy's Northeast Pacific Sound Surveillance System (SOSUS). NOAA's T-Phase Monitoring Program has accessed SOSUS in real-time since 1993, providing the TCS community with detection of seismicity associated with eruptive or tectonic activity along these two ridges. This remote detection of earthquake swarms along the N.E. Pacific mid-ocean ridge coupled to NSF funding for pre-event staging equipment and supplies has allowed directed and increasingly well-organized field responses to the event site. Major rapid and follow-up response cruises have been successfully mounted to 1993 CoAxial, 1996 and 2001 Gorda Ridge, the 1998 Axial Volcano, and 2001 Middle Valley magmatic episodes. The logistical approach required to study these events has been greatly facilitated by the RIDGE/Ridge 2000 programs and collaboration between university, NOAA and Canadian investigators. Not only have our studies of these events significantly impacted our ideas on the nature of crustal accretion, but they also have led to the discovery and preliminary documentation of a previously unrecognized biomass reservoir that lives below the seafloor and is swept out during these cataclysmic events, and to increased appreciation of the formation and thermal, chemical and biogeochemical implications of the 'Event Plumes' commonly associated with sea floor magmatic events. Rapid shore-to-event site response is an important aspect of TCS. Proposals to enhance the event detection and response effort are welcome at any Ridge 2000 target date. The Ridge 2000 program recognizes that even the most rapid ship response will miss the earliest subsurface and water column expressions of magmatic events

  6. Multiple actor-critic structures for continuous-time optimal control using input-output data.

    PubMed

    Song, Ruizhuo; Lewis, Frank; Wei, Qinglai; Zhang, Hua-Guang; Jiang, Zhong-Ping; Levine, Dan

    2015-04-01

    In industrial process control, there may be multiple performance objectives, depending on salient features of the input-output data. Aiming at this situation, this paper proposes multiple actor-critic structures to obtain the optimal control via input-output data for unknown nonlinear systems. The shunting inhibitory artificial neural network (SIANN) is used to classify the input-output data into one of several categories. Different performance measure functions may be defined for disparate categories. The approximate dynamic programming algorithm, which contains model module, critic network, and action network, is used to establish the optimal control in each category. A recurrent neural network (RNN) model is used to reconstruct the unknown system dynamics using input-output data. NNs are used to approximate the critic and action networks, respectively. It is proven that the model error and the closed unknown system are uniformly ultimately bounded. Simulation results demonstrate the performance of the proposed optimal control scheme for the unknown nonlinear system.

  7. Time to look beyond one-year mortality in critically ill hematological patients?

    PubMed

    Moors, Ine; Benoit, Dominique D

    2014-01-01

    The spectacular improvement in long-term prognosis of patients with hematological malignancies since the 1980s, coupled with the subsequent improvement over the past decade in short- and mid-term survival in cases of critical illness, resulted in an increasing referral of such patients to the ICU. A remaining question, however, is how these patients perform in the long term with regard to survival and quality of life. Here we discuss the present multicenter study on survival beyond 1 year in critically ill patients with hematological malignancies. We conclude with suggestions on how we can further improve the long-term outcome of these patients. PMID:24517551

  8. Critical Pedagogy in Uncertain Times: Hope and Possibilities. Education, Politics and Public Life

    ERIC Educational Resources Information Center

    Macrine, Sheila L., Ed.

    2012-01-01

    This book provides comprehensive analyses of issues related to the struggle against the forces of imperial-induced privatization, not just in education, but in all of social life. It situates Critical Pedagogy in the twenty-first century and offers not only critiques but also practical applications, suggestions, and strategies on how attacks can…

  9. Designing for Temporal Awareness: The Role of Temporality in Time-Critical Medical Teamwork

    PubMed Central

    Kusunoki, Diana S.; Sarcevic, Aleksandra

    2016-01-01

    This paper describes the role of temporal information in emergency medical teamwork and how time-based features can be designed to support the temporal awareness of clinicians in this fast-paced and dynamic environment. Engagement in iterative design activities with clinicians over the course of two years revealed a strong need for time-based features and mechanisms, including timestamps for tasks based on absolute time and automatic stopclocks measuring time by counting up since task performance. We describe in detail the aspects of temporal awareness central to clinicians’ awareness needs and then provide examples of how we addressed these needs through the design of a shared information display. As an outcome of this process, we define four types of time representation techniques to facilitate the design of time-based features: (1) timestamps based on absolute time, (2) timestamps relative to the process start time, (3) time since task performance, and (4) time until the next required task. PMID:27478880

  10. Multiple actor-critic structures for continuous-time optimal control using input-output data.

    PubMed

    Song, Ruizhuo; Lewis, Frank; Wei, Qinglai; Zhang, Hua-Guang; Jiang, Zhong-Ping; Levine, Dan

    2015-04-01

    In industrial process control, there may be multiple performance objectives, depending on salient features of the input-output data. Aiming at this situation, this paper proposes multiple actor-critic structures to obtain the optimal control via input-output data for unknown nonlinear systems. The shunting inhibitory artificial neural network (SIANN) is used to classify the input-output data into one of several categories. Different performance measure functions may be defined for disparate categories. The approximate dynamic programming algorithm, which contains model module, critic network, and action network, is used to establish the optimal control in each category. A recurrent neural network (RNN) model is used to reconstruct the unknown system dynamics using input-output data. NNs are used to approximate the critic and action networks, respectively. It is proven that the model error and the closed unknown system are uniformly ultimately bounded. Simulation results demonstrate the performance of the proposed optimal control scheme for the unknown nonlinear system. PMID:25730830

  11. CoR-MAC: Contention over Reservation MAC Protocol for Time-Critical Services in Wireless Body Area Sensor Networks.

    PubMed

    Yu, Jeongseok; Park, Laihyuk; Park, Junho; Cho, Sungrae; Keum, Changsup

    2016-05-09

    Reserving time slots for urgent data, such as life-critical information, seems to be very attractive to guarantee their deadline requirements in wireless body area sensor networks (WBASNs). On the other hand, this reservation imposes a negative impact on performance for the utilization of a channel. This paper proposes a new channel access scheme referred to as the contention over reservation MAC (CoR-MAC) protocol for time-critical services in wireless body area sensor networks. CoR-MAC uses the dual reservation; if the reserved time slots are known to be vacant, other nodes can access the time slots by contention-based reservation to maximize the utilization of a channel and decrease the delay of the data. To measure the effectiveness of the proposed scheme against IEEE 802.15.4 and IEEE 802.15.6, we evaluated their performances with various performance indexes. The CoR-MAC showed 50% to 850% performance improvement in terms of the delay of urgent and time-critical data according to the number of nodes.

  12. CoR-MAC: Contention over Reservation MAC Protocol for Time-Critical Services in Wireless Body Area Sensor Networks.

    PubMed

    Yu, Jeongseok; Park, Laihyuk; Park, Junho; Cho, Sungrae; Keum, Changsup

    2016-01-01

    Reserving time slots for urgent data, such as life-critical information, seems to be very attractive to guarantee their deadline requirements in wireless body area sensor networks (WBASNs). On the other hand, this reservation imposes a negative impact on performance for the utilization of a channel. This paper proposes a new channel access scheme referred to as the contention over reservation MAC (CoR-MAC) protocol for time-critical services in wireless body area sensor networks. CoR-MAC uses the dual reservation; if the reserved time slots are known to be vacant, other nodes can access the time slots by contention-based reservation to maximize the utilization of a channel and decrease the delay of the data. To measure the effectiveness of the proposed scheme against IEEE 802.15.4 and IEEE 802.15.6, we evaluated their performances with various performance indexes. The CoR-MAC showed 50% to 850% performance improvement in terms of the delay of urgent and time-critical data according to the number of nodes. PMID:27171085

  13. CoR-MAC: Contention over Reservation MAC Protocol for Time-Critical Services in Wireless Body Area Sensor Networks

    PubMed Central

    Yu, Jeongseok; Park, Laihyuk; Park, Junho; Cho, Sungrae; Keum, Changsup

    2016-01-01

    Reserving time slots for urgent data, such as life-critical information, seems to be very attractive to guarantee their deadline requirements in wireless body area sensor networks (WBASNs). On the other hand, this reservation imposes a negative impact on performance for the utilization of a channel. This paper proposes a new channel access scheme referred to as the contention over reservation MAC (CoR-MAC) protocol for time-critical services in wireless body area sensor networks. CoR-MAC uses the dual reservation; if the reserved time slots are known to be vacant, other nodes can access the time slots by contention-based reservation to maximize the utilization of a channel and decrease the delay of the data. To measure the effectiveness of the proposed scheme against IEEE 802.15.4 and IEEE 802.15.6, we evaluated their performances with various performance indexes. The CoR-MAC showed 50% to 850% performance improvement in terms of the delay of urgent and time-critical data according to the number of nodes. PMID:27171085

  14. On the convergence of the critical cooling time-scale for the fragmentation of self-gravitating discs

    NASA Astrophysics Data System (ADS)

    Meru, Farzana; Bate, Matthew R.

    2012-12-01

    We carry out simulations of gravitationally unstable discs using a smoothed particle hydrodynamics (SPH) code and a grid-based hydrodynamics code, FARGO, to understand the previous non-convergent results reported by Meru & Bate. We obtain evidence that convergence with increasing resolution occurs with both SPH and FARGO and in both cases we find that the critical cooling time-scale is larger than previously thought. We show that SPH has a first-order convergence rate, while FARGO converges with a second-order rate. We show that the convergence of the critical cooling time-scale for fragmentation depends largely on the numerical viscosity employed in both SPH and FARGO. With SPH, particle velocity dispersion may also play a role. We show that reducing the dissipation from the numerical viscosity leads to larger values of the critical cooling time at a given resolution. For SPH, we find that the effect of the dissipation due to the numerical viscosity is somewhat larger than had previously been appreciated. In particular, we show that using a quadratic term in the SPH artificial viscosity (βSPH) that is too low appears to lead to excess dissipation in gravitationally unstable discs, which may affect any results that sensitively depend on the thermodynamics, such as disc fragmentation. We show that the two codes converge to values of the critical cooling time-scale, βcrit > 20 (for a ratio of specific heats of γ = 5/3), and perhaps even as large as βcrit ≈ 30. These are approximately three to five times larger than has been found by most previous studies. This is equivalent to a maximum gravitational stress that a disc can withstand without fragmenting of αGI, crit ≈ 0.013 - 0.02, which is much smaller than the values typically used in the literature. It is therefore easier for self-gravitating discs to fragment than has been concluded from most past studies.

  15. Real-Time Monitoring of Critical Care Analytes in the Bloodstream with Chemical Sensors: Progress and Challenges

    NASA Astrophysics Data System (ADS)

    Frost, Megan C.; Meyerhoff, Mark E.

    2015-07-01

    We review approaches and challenges in developing chemical sensor-based methods to accurately and continuously monitor levels of key analytes in blood related directly to the status of critically ill hospitalized patients. Electrochemical and optical sensor-based technologies have been pursued to measure important critical care species in blood [i.e., oxygen, carbon dioxide, pH, electrolytes (K+, Na+, Cl-, etc.), glucose, and lactate] in real-time or near real-time. The two main configurations examined to date for achieving this goal have been intravascular catheter sensors and patient attached ex vivo sensors with intermittent blood sampling via an attached indwelling catheter. We discuss the status of these configurations and the main issues affecting the accuracy of the measurements, including cell adhesion and thrombus formation on the surface of the sensors, sensor drift, sensor selectivity, etc. Recent approaches to mitigate these nagging performance issues that have prevented these technologies from clinical use are also discussed.

  16. Visual analytics for finding critical structures in massive time-varying turbulent-flow simulations.

    PubMed

    Gaither, Kelly P; Childs, Hank; Schulz, Karl W; Harrison, Cyrus; Barth, William; Donzis, Diego; Yeung, Pui-Kuen

    2012-01-01

    Visualization and data analysis are crucial in analyzing and understanding a turbulent-flow simulation of size 4,096(3) cells per time slice (68 billion cells) and 17 time slices (one trillion total cells). The visualization techniques used help scientists investigate the dynamics of intense events individually and as these events form clusters.

  17. Long-time tails do not necessarily imply self-organized criticality or the breakdown of the standard transport paradigm

    SciTech Connect

    Krommes, J.A.; Ottaviani, M.

    2000-01-18

    Numerical measurements and analytical studies are performed on a stochastic model with features relevant to plasma confinement. Although the model lacks crucial features of self-organized criticality (SOC) and its transport can be computed by standard techniques, it nevertheless exhibits intermittency and algebraic time correlations. This suggests that SOC need not be the explanation for observed long-time tails in experimental fluctuation data. Arguments based on the renormalized spectral balance equation, and simulation of a standard nonlinear paradigm, predict a range of Hurst exponents in reasonable agreement with the observations without invoking submarginal dynamics.

  18. Critical Care Admissions following Total Laryngectomy: Is It Time to Change Our Practice?

    PubMed Central

    Morgan, Alexandria; Gibson, Bethan; Berry, Sandeep; Jaffery, Ali

    2016-01-01

    Critical Care Unit (CCU) beds are a limited resource and in increasing demand. Studies have shown that complex head and neck patients can be safely managed on a ward setting given the appropriate staffing and support. This retrospective case series aims to quantify the CCU care received by patients following total laryngectomy (TL) at a District General Hospital (DGH) and compare patient outcomes in an attempt to inform current practice. Data relating to TL were collected over a 5-year period from 1st January 2010 to 31st December 2015. A total of 22 patients were included. All patients were admitted to CCU postoperatively for an average length of stay of 25.5 hours. 95% of these patients were admitted to CCU for the purpose of close monitoring only, not requiring any active treatment prior to discharge to the ward. 73% of total complications were encountered after the first 24 hours postoperatively at which point patients had been stepped down to ward care. Avoiding the use of CCU beds and instead providing the appropriate level of care on the ward would result in a potential cost saving of approximately £8,000 with no influence on patient morbidity and mortality. PMID:27752264

  19. Adaptive critic designs for discrete-time zero-sum games with application to H(infinity) control.

    PubMed

    Al-Tamimi, Asma; Abu-Khalaf, Murad; Lewis, Frank L

    2007-02-01

    In this correspondence, adaptive critic approximate dynamic programming designs are derived to solve the discrete-time zero-sum game in which the state and action spaces are continuous. This results in a forward-in-time reinforcement learning algorithm that converges to the Nash equilibrium of the corresponding zero-sum game. The results in this correspondence can be thought of as a way to solve the Riccati equation of the well-known discrete-time H(infinity) optimal control problem forward in time. Two schemes are presented, namely: 1) a heuristic dynamic programming and 2) a dual-heuristic dynamic programming, to solve for the value function and the costate of the game, respectively. An H(infinity) autopilot design for an F-16 aircraft is presented to illustrate the results.

  20. Adaptive critic designs for discrete-time zero-sum games with application to H(infinity) control.

    PubMed

    Al-Tamimi, Asma; Abu-Khalaf, Murad; Lewis, Frank L

    2007-02-01

    In this correspondence, adaptive critic approximate dynamic programming designs are derived to solve the discrete-time zero-sum game in which the state and action spaces are continuous. This results in a forward-in-time reinforcement learning algorithm that converges to the Nash equilibrium of the corresponding zero-sum game. The results in this correspondence can be thought of as a way to solve the Riccati equation of the well-known discrete-time H(infinity) optimal control problem forward in time. Two schemes are presented, namely: 1) a heuristic dynamic programming and 2) a dual-heuristic dynamic programming, to solve for the value function and the costate of the game, respectively. An H(infinity) autopilot design for an F-16 aircraft is presented to illustrate the results. PMID:17278575

  1. A Paradox within the Time Value of Money: A Critical Thinking Exercise for Finance Students

    ERIC Educational Resources Information Center

    Delaney, Charles J.; Rich, Steven P.; Rose, John T.

    2016-01-01

    This study presents a paradox within the time value of money (TVM), namely, that the interest-principal sequence embedded in the payment stream of an amortized loan is exactly the opposite of the interest-principal sequence implicit in the present value of a matching annuity. We examine this inverse sequence, both mathematically and intuitively,…

  2. Eye Colour and Reaction Time: An Opportunity for Critical Statistical Reasoning

    ERIC Educational Resources Information Center

    Watson, Jane

    2008-01-01

    This author was surprised to read a short article in "The Mercury" newspaper in Hobart about blue-eyed people being more intelligent and brown-eyed people having faster reaction times. Such an article invites immediate scepticism from the statistically literate. The lack of data in the article should lead the interested reader to a search for…

  3. Health Monitor for Multitasking, Safety-Critical, Real-Time Software

    NASA Technical Reports Server (NTRS)

    Zoerner, Roger

    2011-01-01

    Health Manager can detect Bad Health prior to a failure occurring by periodically monitoring the application software by looking for code corruption errors, and sanity-checking each critical data value prior to use. A processor s memory can fail and corrupt the software, or the software can accidentally write to the wrong address and overwrite the executing software. This innovation will continuously calculate a checksum of the software load to detect corrupted code. This will allow a system to detect a failure before it happens. This innovation monitors each software task (thread) so that if any task reports "bad health," or does not report to the Health Manager, the system is declared bad. The Health Manager reports overall system health to the outside world by outputting a square wave signal. If the square wave stops, this indicates that system health is bad or hung and cannot report. Either way, "bad health" can be detected, whether caused by an error, corrupted data, or a hung processor. A separate Health Monitor Task is started and run periodically in a loop that starts and stops pending on a semaphore. Each monitored task registers with the Health Manager, which maintains a count for the task. The registering task must indicate if it will run more or less often than the Health Manager. If the task runs more often than the Health Manager, the monitored task calls a health function that increments the count and verifies it did not go over max-count. When the periodic Health Manager runs, it verifies that the count did not go over the max-count and zeroes it. If the task runs less often than the Health Manager, the periodic Health Manager will increment the count. The monitored task zeroes the count, and both the Health Manager and monitored task verify that the count did not go over the max-count.

  4. Is it time to drop the 'knowledge translation' metaphor? A critical literature review.

    PubMed

    Greenhalgh, Trisha; Wieringa, Sietse

    2011-12-01

    The literature on 'knowledge translation' presents challenges for the reviewer because different terms have been used to describe the generation, sharing and application of knowledge and different research approaches embrace different philosophical positions on what knowledge is. We present a narrative review of this literature which deliberately sought to highlight rather than resolve tensions between these different framings. Our findings suggest that while 'translation' is a widely used metaphor in medicine, it constrains how we conceptualise and study the link between knowledge and practice. The 'translation' metaphor has, arguably, led to particular difficulties in the fields of 'evidence-based management' and 'evidence-based policymaking' - where it seems that knowledge obstinately refuses to be driven unproblematically into practice. Many non-medical disciplines such as philosophy, sociology and organization science conceptualise knowledge very differently, as being (for example) 'created', 'constructed', 'embodied', 'performed' and 'collectively negotiated' - and also as being value-laden and tending to serve the vested interests of dominant élites. We propose that applying this wider range of metaphors and models would allow us to research the link between knowledge and practice in more creative and critical ways. We conclude that research should move beyond a narrow focus on the 'know-do gap' to cover a richer agenda, including: (a) the situation-specific practical wisdom (phronesis) that underpins clinical judgement; (b) the tacit knowledge that is built and shared among practitioners ('mindlines'); (c) the complex links between power and knowledge; and (d) approaches to facilitating macro-level knowledge partnerships between researchers, practitioners, policymakers and commercial interests.

  5. Is it time to drop the ‘knowledge translation’ metaphor? A critical literature review

    PubMed Central

    Greenhalgh, Trisha; Wieringa, Sietse

    2011-01-01

    The literature on ‘knowledge translation’ presents challenges for the reviewer because different terms have been used to describe the generation, sharing and application of knowledge and different research approaches embrace different philosophical positions on what knowledge is. We present a narrative review of this literature which deliberately sought to highlight rather than resolve tensions between these different framings. Our findings suggest that while ‘translation’ is a widely used metaphor in medicine, it constrains how we conceptualise and study the link between knowledge and practice. The ‘translation’ metaphor has, arguably, led to particular difficulties in the fields of ‘evidence-based management’ and ‘evidence-based policymaking’ – where it seems that knowledge obstinately refuses to be driven unproblematically into practice. Many non-medical disciplines such as philosophy, sociology and organization science conceptualise knowledge very differently, as being (for example) ‘created’, ‘constructed’, ‘embodied’, ‘performed’ and ‘collectively negotiated’ – and also as being value-laden and tending to serve the vested interests of dominant élites. We propose that applying this wider range of metaphors and models would allow us to research the link between knowledge and practice in more creative and critical ways. We conclude that research should move beyond a narrow focus on the ‘know–do gap’ to cover a richer agenda, including: (a) the situation-specific practical wisdom (phronesis) that underpins clinical judgement; (b) the tacit knowledge that is built and shared among practitioners (‘mindlines’); (c) the complex links between power and knowledge; and (d) approaches to facilitating macro-level knowledge partnerships between researchers, practitioners, policymakers and commercial interests. PMID:22179293

  6. CA1 neurons in the human hippocampus are critical for autobiographical memory, mental time travel, and autonoetic consciousness

    PubMed Central

    Bartsch, Thorsten; Döhring, Juliane; Rohr, Axel; Jansen, Olav; Deuschl, Günther

    2011-01-01

    Autobiographical memories in our lives are critically dependent on temporal lobe structures. However, the contribution of CA1 neurons in the human hippocampus to the retrieval of episodic autobiographical memory remains elusive. In patients with a rare acute transient global amnesia, highly focal lesions confined to the CA1 field of the hippocampus can be detected on MRI. We studied the effect of these lesions on autobiographical memory using a detailed autobiographical interview including the remember/know procedure. In 14 of 16 patients, focal lesions in the CA1 sector of the hippocampal cornu ammonis were detected. Autobiographical memory was significantly affected over all time periods, including memory for remote periods. Impairment of episodic memory and autonoetic consciousness exhibited a strong temporal gradient extending 30 to 40 y into the past. These results highlight the distinct and critical role of human hippocampal CA1 neurons in autobiographical memory retrieval and for re-experiencing detailed episodic memories. PMID:21987814

  7. Real-time dynamics induced by quenches across the quantum critical points in gapless Fermi systems with a magnetic impurity

    NASA Astrophysics Data System (ADS)

    Kleine, Christian; Mußhoff, Julian; Anders, Frithjof B.

    2014-12-01

    The energy-dependent scattering of fermions from a localized orbital at an energy-dependent rate Γ (ɛ ) ∝|ɛ| r gives rise to quantum critical points (QCPs) in the pseudogap single-impurity Anderson model separating a local moment phase with an unscreened spin moment from a strong-coupling phase which slightly deviates from the screened phase of standard Kondo problem. Using the time-dependent numerical renormalization group (TD-NRG) approach we show that local dynamic properties always equilibrate towards a steady-state value even for quenches across the QCP but with systematic deviations from the thermal equilibrium depending on the distance to the critical coupling. Local nonequilibrium properties are presented for interaction quenches and hybridization quenches. We augment our numerical data by an analytical calculation that becomes exact at short times and find excellent agreement between the numerics and the analytical theory. For interaction quenches within the screened phase we find a universal function for the time-dependent local double occupancy. We trace back the discrepancy between our results and the data obtained by a time-dependent Gutzwiller variational approach to restrictions of the wave-function ansatz in the Gutzwiller theory: while the NRG ground states properly account for the formation of an extended spin moment which decouples from the system in the unscreened phase, the Gutzwiller ansatz only allows the formation of the spin moment on the local impurity orbital.

  8. Incidental nutrient transfers: Assessing critical times in agricultural catchments using high-resolution data.

    PubMed

    Shore, Mairead; Jordan, Phil; Melland, Alice R; Mellander, Per-Erik; McDonald, Noeleen; Shortle, Ger

    2016-05-15

    Managing incidental losses associated with liquid slurry applications during closed periods has significant cost and policy implications and the environmental data required to review such a measure are difficult to capture due to storm dependencies. Over four years (2010-2014) in five intensive agricultural catchments, this study used high-resolution total and total reactive phosphorus (TP and TRP), total oxidised nitrogen (TON) and suspended sediment (SS) concentrations with river discharge data to investigate the magnitude and timing of nutrient losses. A large dataset of storm events (defined as 90th percentile discharges), and associated flow-weighted mean (FWM) nutrient concentrations and TP/SS ratios, was used to indicate when losses were indicative of residual or incidental nutrient transfers. The beginning of the slurry closed period was reflective of incidental and residual transfers with high storm FWM P (TP and TRP) concentrations, with some catchments also showing elevated storm TP:SS ratios. This pattern diminished at the end of the closed period in all catchments. Total oxidised N behaved similarly to P during storms in the poorly drained catchments and revealed a long lag time in other catchments. Low storm FWM P concentrations and TP:SS ratios during the weeks following the closed period suggests that nutrients either weren't applied during this time (best times chosen) or that they were applied to less risky areas (best places chosen). For other periods such as late autumn and during wet summers, where storm FWM P concentrations and TP:SS ratios were high, it is recommended that an augmentation of farmer knowledge of soil drainage characteristics with local and detailed current and forecast soil moisture conditions will help to strengthen existing regulatory frameworks to avoid storm driven incidental nutrient transfers. PMID:26933967

  9. miRNAs are required for generating a time-delay critical for the circadian oscillator

    PubMed Central

    Chen, Rongmin; D’Alessandro, Matthew; Lee, Choogon

    2013-01-01

    Background Circadian clocks coordinate an organism’s activities and regulate metabolic homeostasis in relation to daily environmental changes, most notably light/dark cycles. As in other organisms, the timekeeping mechanism in mammals depends on a self-sustaining transcriptional negative feedback loop with a built-in time delay in feedback inhibition. Although the time delay is essential for generating a slow, self-sustaining negative feedback loop with a period close to 24 hours, the exact mechanisms underlying the time delay are not known. Results We show here that RNA interference mediated by microRNAs (miRNAs) is an essential mechanism in generating the time delay. In Dicer-deficient (and thus miRNA-deficient) cells and mice, circadian rhythms were dramatically shortened (by ~2 hours), although the rhythms remained robust. The period shortening was caused by faster PER1 and PER2 translation in the Dicer-deficient cells. We also identified three specific miRNAs that regulate Per expression, and showed that knockdown of these miRNAs in wild-type cells also shortened the circadian period. Conclusions Consistent with the canonical function of miRNAs as translational modulators of target genes and their widespread roles in cell physiology, circadian rhythms are also modulated by miRNA-mediated RNA interference acting on posttranscriptional regulation of key clock genes. Our present study definitively shows that RNA interference is an important modulator of circadian rhythms by controlling the pace of PER synthesis, and presents a novel layer of regulation for the clock. PMID:24094851

  10. Does Be10 Underestimate Residence Time of Critical Zones in Acid Environments?

    NASA Astrophysics Data System (ADS)

    Richter, D., Jr.

    2014-12-01

    Meteoric 10Be inventories were coupled with with mass balance of 9Be (bedrock to 18.3 meters soil-saprolite profile) to estimate the soil residence time (SRT) of a biogeomorphically stable Ultisol. We estimate SRT after correcting for observed9Be losses, which indicate that more than half of the 9Be weathered from primary minerals had been leached from the soil and saprolite. Our estimates of minimum SRT range between 1.3-1.4 Ma and between 2.6-3.1 Ma under high and low (2.0 and 1.3 × 106 atoms cm-2 yr-1, respectively) estimates of atmospheric 10Be deposition. Denudation rates of the physiographic region corroborate our residence time estimates. We double to quadruple the pedogenic time constraints of interfluves on the Southern Piedmont, and demonstrate that assumptions of complete meteoric 10Be retention in acidic soil systems need questioning. The results may have far-reaching consequences for soil, sediment, river, and ocean research using meteoric 10Be.

  11. Task-oriented quality assessment and adaptation in real-time mission critical video streaming applications

    NASA Astrophysics Data System (ADS)

    Nightingale, James; Wang, Qi; Grecos, Christos

    2015-02-01

    In recent years video traffic has become the dominant application on the Internet with global year-on-year increases in video-oriented consumer services. Driven by improved bandwidth in both mobile and fixed networks, steadily reducing hardware costs and the development of new technologies, many existing and new classes of commercial and industrial video applications are now being upgraded or emerging. Some of the use cases for these applications include areas such as public and private security monitoring for loss prevention or intruder detection, industrial process monitoring and critical infrastructure monitoring. The use of video is becoming commonplace in defence, security, commercial, industrial, educational and health contexts. Towards optimal performances, the design or optimisation in each of these applications should be context aware and task oriented with the characteristics of the video stream (frame rate, spatial resolution, bandwidth etc.) chosen to match the use case requirements. For example, in the security domain, a task-oriented consideration may be that higher resolution video would be required to identify an intruder than to simply detect his presence. Whilst in the same case, contextual factors such as the requirement to transmit over a resource-limited wireless link, may impose constraints on the selection of optimum task-oriented parameters. This paper presents a novel, conceptually simple and easily implemented method of assessing video quality relative to its suitability for a particular task and dynamically adapting videos streams during transmission to ensure that the task can be successfully completed. Firstly we defined two principle classes of tasks: recognition tasks and event detection tasks. These task classes are further subdivided into a set of task-related profiles, each of which is associated with a set of taskoriented attributes (minimum spatial resolution, minimum frame rate etc.). For example, in the detection class

  12. Platelets are not critical effector cells for the time course of murine passive crescentic glomerulonephritis.

    PubMed

    Hohenstein, Bernd; Daniel, Christoph; Johnson, Richard J; Amann, Kerstin U; Hugo, Christian P M

    2013-01-01

    Although platelets are well-known effector cells of inflammatory renal disease, clinical studies were not able to establish platelet inhibition as an effective therapy. Our previous studies using Vasodilator stimulated Phosphoprotein- and P2Y1-deficient mice suggested some early, but no long-term effects of platelets in passive crescentic glomerulonephritis. To define the role of platelets for this disease model, passive crescentic glomerulonephritis was induced in 72 C57Bl/6 mice by intraperitoneal injection of sheep anti-rabbit glomerular basement membrane antibody on 2 consecutive days. Platelets were depleted using anti-glycoprotein Ibα antibodies (p0p3/p0p4) every 4th day. Mice treated with equal amounts of sterile Phosphate buffered solution or rat-IgG served as controls. Blood, urine, and tissues were harvested on days 3 and 28. Renal tissue sections were evaluated after immunostaining using (semi)quantitative and computer-assisted image analysis. Compared to controls, efficient depletion was achieved as indicated by a markedly prolonged bleeding time and a more than 90% reduction in platelet counts (800/nl vs. 42/nl; P < 0.001). Functional (creatinine-clearance and proteinuria) parameters demonstrated no significant differences between the groups. Neither parameters of renal injury (glomerulosclerosis and fibrosis) nor glomerular/tubulointerstitial matrix expansion (by collagen IV staining), glomerular capillary rarefaction (lectin staining), and the glomerular/tubulointerstitial proliferative response (proliferating cell nuclear antigen) demonstrated any differences between platelet-depleted mice and PBS- or rat-IgG-treated nephritic mice at any time point. Despite effective platelet inhibition/depletion, neither the short- nor long-term course of passive crescentic nephrotoxic nephritis was affected. These data indicate that platelets play a minor role during the time course of this disease model in the mouse.

  13. Biomedical real-time monitoring in restricted and safety-critical environments

    PubMed Central

    Astaras, A; Bamidis, P D; Kourtidou-Papadeli, C; Maglaveras, N

    2008-01-01

    Biomedical signal monitoring can counteract the risk of human operator error due to inattention or fatigue in safetycritical and restrictive environments, such as in aviation, space, automobile and heavy industrial machinery operation. Real-time biomedical data acquisition is changing through advances in microelectronics fabrication, bio-MEMS and power micro-generators. Such data acquisition and processing systems are becoming increasingly miniaturised, flexible and pervasive, while data is being collected from inside the human body as well as around it. In this paper we review two related research projects exploiting this technological convergence, discuss its implications and suggest future innovation prospects through further similar cross-disciplinary synergies. PMID:19048087

  14. Frequency and Time Domain Analysis of Foetal Heart Rate Variability with Traditional Indexes: A Critical Survey.

    PubMed

    Romano, Maria; Iuppariello, Luigi; Ponsiglione, Alfonso Maria; Improta, Giovanni; Bifulco, Paolo; Cesarelli, Mario

    2016-01-01

    Monitoring of foetal heart rate and its variability (FHRV) covers an important role in assessing health of foetus. Many analysis methods have been used to get quantitative measures of FHRV. FHRV has been studied in time and in frequency domain and interesting clinical results have been obtained. Nevertheless, a standardized definition of FHRV and a precise methodology to be used for its evaluation are lacking. We carried out a literature overview about both frequency domain analysis (FDA) and time domain analysis (TDA). Then, by using simulated FHR signals, we defined the methodology for FDA. Further, employing more than 400 real FHR signals, we analysed some of the most common indexes, Short Term Variability for TDA and power content of the spectrum bands and sympathovagal balance for FDA, and evaluated their ranges of values, which in many cases are a novelty. Finally, we verified the relationship between these indexes and two important parameters: week of gestation, indicator of foetal growth, and foetal state, classified as active or at rest. Our results indicate that, according to literature, it is necessary to standardize the procedure for FHRV evaluation and to consider week of gestation and foetal state before FHR analysis. PMID:27195018

  15. Critical role of sorafenib exposure over time for its antitumor activity in thyroid cancer.

    PubMed

    Bellesoeur, Audrey; Carton, Edith; Mir, Olivier; Groussin, Lionel; Blanchet, Benoit; Billemont, Bertrand; Clerc, Jérôme; Goldwasser, François

    2014-06-01

    Sorafenib, a multi-kinase inhibitor that targets the VEGF, PDGF and BRAF pathways, has demonstrated significant clinical activity in metastatic differentiated thyroid cancer. However, all patients eventually experience disease progression with a median progression-free survival close to 10 months. Since sorafenib exposure is known to decrease over time, we hypothesized that dose adjustments aiming to restore adequate exposure could lead to further clinical activity. We report, as a proof of concept on a patient with radio-iodine resistant metastatic thyroid cancer, who experienced disease progression after an initial response to sorafenib (400 mg twice daily). Whereas the thyroglobulin-progression-free survival at standard doses was 6 months, iterative dose optimization led to a prolonged progression-free survival up to 41 months. Sorafenib doses were increased up to 1600 mg bid, in order to maintain clinical activity, and to restore active plasma concentration, since sorafenib exposure had decreased over the time. Toxicity was mild and manageable for more than 2 years. However, the patient eventually experienced grade 3 proteinuria leading to treatment discontinuation. This observation opens up new horizons for daily management of radioactive iodine-refractory differentiated thyroid cancer patients progressing under standard doses of sorafenib, and stress the need to monitor its plasma concentration.

  16. Critical analysis of rhinovirus RNA load quantification by real-time reverse transcription-PCR.

    PubMed

    Schibler, Manuel; Yerly, Sabine; Vieille, Gaël; Docquier, Mylène; Turin, Lara; Kaiser, Laurent; Tapparel, Caroline

    2012-09-01

    Rhinoviruses are the most frequent cause of human respiratory infections, and quantitative rhinovirus diagnostic tools are needed for clinical investigations. Although results obtained by real-time reverse-transcription PCR (RT-PCR) assays are frequently converted to viral RNA loads, this presents several limitations regarding accurate virus RNA quantification, particularly given the need to reliably quantify all known rhinovirus genotypes with a single assay. Using an internal extraction control and serial dilutions of an in vitro-transcribed rhinovirus RNA reference standard, we validated a quantitative one-step real-time PCR assay. We then used chimeric rhinovirus genomes with 5'-untranslated regions (5'UTRs) originating from the three rhinovirus species and from one enterovirus to estimate the impact of the 5'UTR diversity. Respiratory specimens from infected patients were then also analyzed. The assay quantification ability ranged from 4.10 to 9.10 log RNA copies/ml, with an estimated error margin of ±10%. This variation was mainly linked to target variability and interassay variability. Taken together, our results indicate that our assay can reliably estimate rhinovirus RNA load, provided that the appropriate error margin is used. In contrast, due to the lack of a universal rhinovirus RNA standard and the variability related to sample collection procedures, accurate absolute rhinovirus RNA quantification in respiratory specimens is currently hardly feasible.

  17. Frequency and Time Domain Analysis of Foetal Heart Rate Variability with Traditional Indexes: A Critical Survey

    PubMed Central

    Romano, Maria; Iuppariello, Luigi; Ponsiglione, Alfonso Maria; Improta, Giovanni; Bifulco, Paolo; Cesarelli, Mario

    2016-01-01

    Monitoring of foetal heart rate and its variability (FHRV) covers an important role in assessing health of foetus. Many analysis methods have been used to get quantitative measures of FHRV. FHRV has been studied in time and in frequency domain and interesting clinical results have been obtained. Nevertheless, a standardized definition of FHRV and a precise methodology to be used for its evaluation are lacking. We carried out a literature overview about both frequency domain analysis (FDA) and time domain analysis (TDA). Then, by using simulated FHR signals, we defined the methodology for FDA. Further, employing more than 400 real FHR signals, we analysed some of the most common indexes, Short Term Variability for TDA and power content of the spectrum bands and sympathovagal balance for FDA, and evaluated their ranges of values, which in many cases are a novelty. Finally, we verified the relationship between these indexes and two important parameters: week of gestation, indicator of foetal growth, and foetal state, classified as active or at rest. Our results indicate that, according to literature, it is necessary to standardize the procedure for FHRV evaluation and to consider week of gestation and foetal state before FHR analysis. PMID:27195018

  18. A Critical Review of the Time Series of Total Solar Irradiance Satellite Observations

    NASA Astrophysics Data System (ADS)

    Willson, R. C.

    2006-12-01

    Continuous time series of total solar irradiance (TSI) observations have been constructed from the set of contiguous, redundant, overlapping total solar irradiance (TSI) measurements made by satellite experiments during the past 28 years. One, the ACRIM composite time series [Willson &Mordvinov, 2003], detects a significant upward trend in TSI of 0.04 percent per decade during solar cycles 21-23. Another, the PMOD composite [Frohlich &Lean, 1998], detects no significant trend using different combinations of TSI data sets, computational philosophy and assumptions. The potential significance of the ACRIM upward trend as a climate forcing makes it important to explore the trend difference to determine which of the two composite TSI time series best represents the measurement database. Two types of experiments have provided TSI data: self-calibrating, precision TSI monitors and Earth radiation budget (ERB) experiments. TSI monitors provide much higher accuracy and precision and are capable of self- calibrating the degradation of their sensors. The ERB experiments are designed to provide less accurate and precise TSI `boundary value' results for ERB modeling and cannot self-calibrate sensor degradation. While the optimum composite TSI time series utilizes TSI monitor results to the maximum extent possible, a two year gap in the TSI monitoring record between the ACRIM1 and ACRIM2 experiments (1989 - 1991) would have prevented compilation of a continuous record over the 28 years of satellite observations were it not for the availability of ERB results during the gap. The relationship between ACRIM1 and ACRIM2 results across the ACRIM gap can be derived using the overlapping ERB data sets: the Nimbus7/ERB and/or the ERBS/ERBE. These two choices are embodied in the construction of ACRIM and PMOD composites, respectively. The philosophy of the ACRIM composite is to use the unaltered results published by the experiment science teams and the Nimbus7/ERB ACRIM gap ratio. The

  19. On the time to reach a critical number of infections in epidemic models with infective and susceptible immigrants.

    PubMed

    Almaraz, E; Gómez-Corral, A; Rodríguez-Bernal, M T

    2016-06-01

    In this paper we examine the time T to reach a critical number K0 of infections during an outbreak in an epidemic model with infective and susceptible immigrants. The underlying process X, which was first introduced by Ridler-Rowe (1967), is related to recurrent diseases and it appears to be analytically intractable. We present an approximating model inspired from the use of extreme values, and we derive formulae for the Laplace-Stieltjes transform of T and its moments, which are evaluated by using an iterative procedure. Numerical examples are presented to illustrate the effects of the contact and removal rates on the expected values of T and the threshold K0, when the initial time instant corresponds to an invasion time. We also study the exact reproduction number Rexact,0 and the population transmission number Rp, which are random versions of the basic reproduction number R0. PMID:27068519

  20. Timing of Environmental Exposures as a Critical Element in Breast Cancer Risk

    PubMed Central

    Birnbaum, Linda S.

    2015-01-01

    Objective: The role of the chemical environment in disease initiation or progression is becoming more evident. Endocrine disruption via environmental chemicals is now well documented in humans, rodent research models, and wildlife. Breast cancer is an endocrine-based disease whose risk may be modified by environmental exposures. Our purpose is to encourage more investigation into early life environmental exposures as they relate to breast cancer risk factors and disease over a lifetime. Evidence: The 2009 President's Cancer Panel, 2012 Institute of Medicine, 2013 Interagency Breast Cancer and the Environment Research Coordinating Committee reports, and research publications dated ≥2012 in PubMed were used to inform our perspective. Consensus Process: Literature was reviewed and evidence gathered on the effects of the environment on risk of breast cancer or mammary tumor development in animal research models as it pertained to the influence of timing of exposure on later-life outcomes. Conclusions: Evidence has accumulated for several chemicals that environmental factors have a stronger effect on breast cancer risk when exposure occurred early in life. The insecticide, dichlorodiphenyltrichloroethane, is an excellent example and is just one of several chemicals for which there seems to be both animal and human evidence for the developmental basis of adult disease. The developing breast undergoes many changes in early life, leaving it vulnerable to the effects of epigenetic marks, endocrine disruption, and carcinogens. More research is needed in the area of early beginnings of breast cancer, with prevention of the disease as the ultimate goal. PMID:26214118

  1. Statistical Analysis of fMRI Time-Series: A Critical Review of the GLM Approach.

    PubMed

    Monti, Martin M

    2011-01-01

    Functional magnetic resonance imaging (fMRI) is one of the most widely used tools to study the neural underpinnings of human cognition. Standard analysis of fMRI data relies on a general linear model (GLM) approach to separate stimulus induced signals from noise. Crucially, this approach relies on a number of assumptions about the data which, for inferences to be valid, must be met. The current paper reviews the GLM approach to analysis of fMRI time-series, focusing in particular on the degree to which such data abides by the assumptions of the GLM framework, and on the methods that have been developed to correct for any violation of those assumptions. Rather than biasing estimates of effect size, the major consequence of non-conformity to the assumptions is to introduce bias into estimates of the variance, thus affecting test statistics, power, and false positive rates. Furthermore, this bias can have pervasive effects on both individual subject and group-level statistics, potentially yielding qualitatively different results across replications, especially after the thresholding procedures commonly used for inference-making.

  2. Statistical Analysis of fMRI Time-Series: A Critical Review of the GLM Approach

    PubMed Central

    Monti, Martin M.

    2011-01-01

    Functional magnetic resonance imaging (fMRI) is one of the most widely used tools to study the neural underpinnings of human cognition. Standard analysis of fMRI data relies on a general linear model (GLM) approach to separate stimulus induced signals from noise. Crucially, this approach relies on a number of assumptions about the data which, for inferences to be valid, must be met. The current paper reviews the GLM approach to analysis of fMRI time-series, focusing in particular on the degree to which such data abides by the assumptions of the GLM framework, and on the methods that have been developed to correct for any violation of those assumptions. Rather than biasing estimates of effect size, the major consequence of non-conformity to the assumptions is to introduce bias into estimates of the variance, thus affecting test statistics, power, and false positive rates. Furthermore, this bias can have pervasive effects on both individual subject and group-level statistics, potentially yielding qualitatively different results across replications, especially after the thresholding procedures commonly used for inference-making. PMID:21442013

  3. Estimation of ground water residence times in the Critical zone: insight from U activity ratios

    NASA Astrophysics Data System (ADS)

    Chabaux, Francois; Ackerer, Julien; Lucas, Yann; viville, Daniel

    2016-04-01

    The use of radioactive disequilibria as tracers and chronometers of weathering processes and related mass transfers has been recognized since the 60'. The development, over the last two decades, of analytical methods for measuring very precisely U-series nuclides (especially, 234U, 230Th and 226Ra) in environmental samples has opened up new scientific applications in Earth Surface Sciences. Here, we propose to present the potential of U activity ratios in surface waters as chronometer of water transfers at a watershed scale. This will be illustrated from studies performed at different scales, with the analysis of U activity ratios in surface waters from small watersheds (Strengbach and Ringelbach watersheds in the Vosges Mountain, France) but also from watersheds of much more regional extension (e.g., the Upper Rhine basin or the Ganges basin). These various studies show that variations of U activity ratios in surface waters are mainly associated with 234U-238U fractionations occurring during the water transfer within the bedrock, which intensity depends on two main parameters: the petro-physical characteristics of the aquifer, principally the geometry of water-rock interfaces and the duration of the water-rock interactions. This readily explains why different U activity ratios (UAR) can be observed in the different aquifers of a continental hydrosystem and hence why UAR can be used to trace the source of river waters. For a hydrological system developed on a substratum marked by fairly homogeneous petro-physical characteristics, the main parameter controlling the UAR in waters draining such a system would be the duration of the water-rock interactions. Variations of UAR in stream or spring waters of such a system can therefore be modeled using simple reactive transport model, which allows the estimation of both the dissolution rate of the bedrock and the residence time of the waters within the aquifer.

  4. Direct analysis in real time--a critical review on DART-MS.

    PubMed

    Gross, Jürgen H

    2014-01-01

    Direct analysis in real time mass spectrometry (DART-MS) has become an established technique for rapid mass spectral analysis of a large variety of samples. DART-MS is capable of analyzing the sample at atmospheric pressure, essentially in the open laboratory environment. DART-MS can be applied to compounds that have been deposited or adsorbed on to surfaces or that are being desorbed therefrom into the atmosphere. This makes DART-MS suitable and well-known for analysis of ingredients of plant materials, pesticide monitoring on vegetables, forensic and safety applications such as screening for traces of explosives, warfare agents, or illicit drugs on luggage, clothes, or bank notes, etc. DART can also be used for analysis of either solid or liquid bulk materials, as may be required in quality control, or to quickly investigate the identity of a compound from chemical synthesis. Even living organisms can be subjected to DART-MS. Driven by different needs in analytical practice, the combination of the DART ionization source and interface can be configured in multiple geometries and with various accessories to adapt the setup as required. Analysis by DART-MS relies on some sort of gas-phase ionization mechanism. In DART, initial generation of the ionizing species is by use of a corona discharge in a pure helium atmosphere which delivers excited helium atoms that, upon their release into the atmosphere, will initiate a cascade of gas-phase reactions. In the end, this results in reagent ions created from atmospheric water or (solvent) vapor in the vicinity of the surface subject to analysis where they effect a chemical ionization process. DART ionization processes may generate positive or negative ions, predominantly even-electron species, but odd-electron species do also occur. The prevailing process of analyte ion formation from a given sample is highly dependent on analyte properties. PMID:24036523

  5. Sediment residence times constrained by uranium-series isotopes: A critical appraisal of the comminution approach

    NASA Astrophysics Data System (ADS)

    Handley, Heather K.; Turner, Simon; Afonso, Juan C.; Dosseto, Anthony; Cohen, Tim

    2013-02-01

    Quantifying the rates of landscape evolution in response to climate change is inhibited by the difficulty of dating the formation of continental detrital sediments. We present uranium isotope data for Cooper Creek palaeochannel sediments from the Lake Eyre Basin in semi-arid South Australia in order to attempt to determine the formation ages and hence residence times of the sediments. To calculate the amount of recoil loss of 234U, a key input parameter used in the comminution approach, we use two suggested methods (weighted geometric and surface area measurement with an incorporated fractal correction) and typical assumed input parameter values found in the literature. The calculated recoil loss factors and comminution ages are highly dependent on the method of recoil loss factor determination used and the chosen assumptions. To appraise the ramifications of the assumptions inherent in the comminution age approach and determine individual and combined comminution age uncertainties associated to each variable, Monte Carlo simulations were conducted for a synthetic sediment sample. Using a reasonable associated uncertainty for each input factor and including variations in the source rock and measured (234U/238U) ratios, the total combined uncertainty on comminution age in our simulation (for both methods of recoil loss factor estimation) can amount to ±220-280 ka. The modelling shows that small changes in assumed input values translate into large effects on absolute comminution age. To improve the accuracy of the technique and provide meaningful absolute comminution ages, much tighter constraints are required on the assumptions for input factors such as the fraction of α-recoil lost 234Th and the initial (234U/238U) ratio of the source material. In order to be able to directly compare calculated comminution ages produced by different research groups, the standardisation of pre-treatment procedures, recoil loss factor estimation and assumed input parameter values

  6. Orthodontics and esthetics of the face: from the "canons" of ancient times to contemporary pluralism. A critical review.

    PubMed

    Ioannidou-Marathiotou, Ioulia; Papamanou, Despoina A; Papadopoulos, Moschos A

    2008-01-01

    Efforts to define facial esthetics and natural attraction using objective criteria go back in time. Nowadays, the abundance of available information, the evolution in our understanding, the intermeshing of the neurosciences and biology, as well as the potential of digital technology, have provided new elements for the objective definition of esthetics and shaped new perceptions and perspectives. The aim of this paper is to attempt a critical analysis from a clinical orthodontic perspective of the conventional methods assessing facial beauty as well as of the trends and viewpoints that form today's concept of an esthetically ideal face, based on a historical review from ancient times to the 21st century. It appears that the "beauty standards" formulated artificially by the mass media and the internet remain a challenge for the orthodontist, who is called upon to explore the aspirations, motives and expectations of patients in order to be able to contribute in improving their social status and quality of life. PMID:19350056

  7. Orthodontics and esthetics of the face: from the "canons" of ancient times to contemporary pluralism. A critical review.

    PubMed

    Ioannidou-Marathiotou, Ioulia; Papamanou, Despoina A; Papadopoulos, Moschos A

    2008-01-01

    Efforts to define facial esthetics and natural attraction using objective criteria go back in time. Nowadays, the abundance of available information, the evolution in our understanding, the intermeshing of the neurosciences and biology, as well as the potential of digital technology, have provided new elements for the objective definition of esthetics and shaped new perceptions and perspectives. The aim of this paper is to attempt a critical analysis from a clinical orthodontic perspective of the conventional methods assessing facial beauty as well as of the trends and viewpoints that form today's concept of an esthetically ideal face, based on a historical review from ancient times to the 21st century. It appears that the "beauty standards" formulated artificially by the mass media and the internet remain a challenge for the orthodontist, who is called upon to explore the aspirations, motives and expectations of patients in order to be able to contribute in improving their social status and quality of life.

  8. A decision-theoretic approach to the display of information for time-critical decisions: The Vista project

    NASA Technical Reports Server (NTRS)

    Horvitz, Eric; Ruokangas, Corinne; Srinivas, Sampath; Barry, Matthew

    1993-01-01

    We describe a collaborative research and development effort between the Palo Alto Laboratory of the Rockwell Science Center, Rockwell Space Operations Company, and the Propulsion Systems Section of NASA JSC to design computational tools that can manage the complexity of information displayed to human operators in high-stakes, time-critical decision contexts. We shall review an application from NASA Mission Control and describe how we integrated a probabilistic diagnostic model and a time-dependent utility model, with techniques for managing the complexity of computer displays. Then, we shall describe the behavior of VPROP, a system constructed to demonstrate promising display-management techniques. Finally, we shall describe our current research directions on the Vista 2 follow-on project.

  9. Longitudinal Impact of a Family Critical Time Intervention on Children in High-Risk Families Experiencing Homelessness: A Randomized Trial.

    PubMed

    Shinn, Marybeth; Samuels, Judith; Fischer, Sean N; Thompkins, Amanda; Fowler, Patrick J

    2015-12-01

    A randomized trial compared effects of a Family Critical Time Intervention (FCTI) to usual care for children in 200 newly homeless families in which mothers had diagnosable mental illness or substance problems. Adapted from an evidence-based practice to prevent chronic homelessness for adults with mental illnesses, FCTI combines housing and structured, time-limited case management to connect families leaving shelter with community services. Families were followed at five time points over 24 months. Data on 311 children-99 ages 1.5-5 years, 113 ages 6-10 years, and 99 ages 11-16 years-included mother-, teacher-, and child-reports of mental health, school experiences, and psychosocial well-being. Analyses used hierarchical linear modeling to investigate intervention effects and changes in child functioning over time. Referral to FCTI reduced internalizing and externalizing problems in preschool-aged children and externalizing for adolescents 11-16. The intervention led to declines in self-reported school troubles for children 6-10 and 11-16. Both experimental and control children in all age groups showed reductions in symptoms over time. Although experimental results were scattered, they suggest that FCTI has the potential to improve mental health and school outcomes for children experiencing homelessness.

  10. The critical relationship between the timing of stimulus presentation and data acquisition in blocked designs with fMRI.

    PubMed

    Price, C J; Veltman, D J; Ashburner, J; Josephs, O; Friston, K J

    1999-07-01

    This paper concerns the experimental design and statistical models employed by fMRI activation studies which block presentation of linguistic stimuli. In particular, we note that the relationship between the timing of stimulus presentation and data acquisition can have a substantial impact on the ability to detect activations in critical language areas, even when the stimuli are presented in blocks. Using a blocked word rhyming paradigm and repeated investigations on a single subject, activation was observed in Broca's area (left inferior frontal cortex) and Wernicke's area (left posterior temporoparietal cortex) when (i) the timing of data acquisition was distributed throughout the peristimulus time and (ii) an event-related analysis was used to model the phasic nature of the hemodynamic response within each block of repeated word stimuli. In contrast, when the timing of data acquisition relative to stimulus presentation was fixed, activation was detected in Broca's area but not consistently in Wernicke's area. Our results indicate that phasic responses to stimuli occur even in a blocked design and that the sampling and proper modeling of these responses can have profound effects on their detection. Specifically, distributed sampling over peristimulus time is essential in order to detect small activations particularly when they are transient. These findings are likely to generalize to the detection of transient signals in any cognitive paradigm.

  11. Riding the Lexical Speedway: A Critical Review on the Time Course of Lexical Selection in Speech Production

    PubMed Central

    Strijkers, Kristof; Costa, Albert

    2011-01-01

    Speech requires time. How much time often depends on the amount of labor the brain has to perform in order to retrieve the linguistic information related to the ideas we want to express. Although most psycholinguistic research in the field of language production has focused on the net result of time required to utter words in various experimental conditions, over the last years more and more researchers pursued the objective to flesh out the time course of particular stages implicated in language production. Here we critically review these studies, with particular interest for the time course of lexical selection. First, we evaluate the data underlying the estimates of an influential temporal meta-analysis on language production (Indefrey and Levelt, 2004). We conclude that those data alone are not sufficient to provide a reliable time frame of lexical selection. Next, we discuss recent neurophysiological evidence which we argue to offer more explicit insights into the time course of lexical selection. Based on this evidence we suggest that, despite the absence of a clear time frame of how long lexical selection takes, there is sufficient direct evidence to conclude that the brain initiates lexical access within 200 ms after stimulus presentation, hereby confirming Indefrey and Levelt’s estimate. In a final section, we briefly review the proposed mechanisms which could lead to this rapid onset of lexical access, namely automatic spreading activation versus specific concept selection, and discuss novel data which support the notion of spreading activation, but indicate that the speed with which this principle takes effect is driven by a top-down signal in function of the intention to engage in a speech act. PMID:22144973

  12. Long-time behavior of the velocity autocorrelation function at low densities and near the critical point of simple fluids.

    PubMed

    Dib, R F A; Ould-Kaddour, F; Levesque, D

    2006-07-01

    Numerous theoretical and numerical works have been devoted to the study of the algebraic decrease at large times of the velocity autocorrelation function of particles in a fluid. The derivation of this behavior, the so-called long-time tail, generally based on linearized hydrodynamics, makes no reference to any specific characteristic of the particle interactions. However, in the literature doubts have been expressed about the possibility that by numerical simulations the long-time tail can be observed in the whole fluid phase domain of systems in which the particles interact by soft-core and attractive pair potentials. In this work, extensive and accurate molecular-dynamics simulations establish that the predicted long-time tail of the velocity autocorrelation function exists in a low-density fluid of particles interacting by a soft-repulsive potential and near the liquid-gas critical point of a Lennard-Jones system. These results contribute to the confirmation that the algebraic decay of the velocity autocorrelation function is universal in these fluid systems.

  13. Quantum critical point of Dirac fermions studied using efficient continuous-time projector quantum Monte Carlo method

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Iazzi, Mauro; Corboz, Philippe; Troyer, Matthias

    2015-03-01

    Quantum phase transition (QPT) of Dirac fermions is a fascinating topic both in condensed matter and in high energy physics. Besides its immediate connection to fundamental problems like mass generation and exotic phases of matter, it provides a common playground where state of the art numerical simulations can be crosschecked with various effective field theory predictions, thus deepen our understanding of both fields. The universality class of the QPT is fundamentally different from the usual bosonic field theory because of the coupling to the gapless fermionic mode at the critical point. We study lattice models with spinless and multi-flavor Dirac fermions using the newly developed efficient continuous-time projector quantum Monte Carlo method. Besides eliminating the Trotter error, the method also enables us to directly calculate derivative observables in a continuous range of interaction strengths, thus greatly enhancing the resolution of the quantum critical region. Compatible results are also obtained from infinite projected entangled-pair states calculations. We compare these numerical results with predictions of the Gross-Neveu theory and discuss their physical implications.

  14. Variability of Residence Time tracer Concentrations at the Southern Sierra Critical Zone Observatory during the California Drought

    NASA Astrophysics Data System (ADS)

    Visser, A.; Thaw, M.; Stacy, E.; Hunsaker, C. T.; Bibby, R. K.; Deinhart, A.; Schorzman, K.; Egnatuk, C. M.; Conklin, M. H.; Esser, B.

    2015-12-01

    California water supply from high elevation snow melt is vulnerable to climate change and prolonged drought conditions. Reduced snow pack and earlier snow melt will result in a greater reliance on man-made reservoirs and subsurface catchment storage. To gain insight into the subsurface storage volume of high elevation catchments, we studied the residence time distribution of surface water leaving the Southern Sierra Critical Zone Observatory. Since October 2014, we have collected monthly samples of two residence time tracers with contrasting half-lives: sulfur-35 (87.5 days) and tritium (12.32 years). Upstream catchment area at the three nested sampling locations is 1 km2 (P301 sub-catchment), 4 km2 (Providence Creek) and ~50 km2 (Big Creek). Samples were analyzed at LLNL by low level liquid scintillation counting and noble gas mass spectrometry after helium accumulation. Variations in tracer concentrations in precipitation, both for tritium (11-24 pCi/L) and sulfur-35 (24-100 mBq/L), complicate straightforward interpretation of residence times. Sulfur-35 concentrations show that last year precipitation contributes 1% - 10% of total stream flow, even during peak snowmelt. Tritium concentrations in stream flow vary between 40% and 60% of the initial concentration in precipitation (15.5 pCi/L), indicating that water leaving the catchment has a residence time on the order of years to decades. Additional analyses of sodium-22 (2.6 year half-life) will aid in deconvoluting the residence time distribution. These low tracer concentrations can be attributed to current severe drought conditions, resulting in low discharge rates and longer residence times. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-675107

  15. Neurokinin B is critical for normal timing of sexual maturation but dispensable for adult reproductive function in female mice.

    PubMed

    True, Cadence; Nasrin Alam, Sayeda; Cox, Kimberly; Chan, Yee-Ming; Seminara, Stephanie B

    2015-04-01

    Humans carrying mutations in neurokinin B (NKB) or the NKB receptor fail to undergo puberty due to decreased secretion of GnRH. Despite this pubertal delay, many of these patients go on to achieve activation of their hypothalamic-pituitary-gonadal axis in adulthood, a phenomenon termed reversal, indicating that NKB signaling may play a more critical role for the timing of pubertal development than adult reproductive function. NKB receptor-deficient mice are hypogonadotropic but have no defects in the timing of sexual maturation. The current study has performed the first phenotypic evaluation of mice bearing mutations in Tac2, the gene encoding the NKB ligand, to determine whether they have impaired sexual development similar to their human counterparts. Male Tac2-/- mice showed no difference in the timing of sexual maturation or fertility compared with wild-type littermates and were fertile. In contrast, Tac2-/- females had profound delays in sexual maturation, with time to vaginal opening and first estrus occurring significantly later than controls, and initial abnormalities in estrous cycles. However, cycling recovered in adulthood and Tac2-/- females were fertile, although they produced fewer pups per litter. Thus, female Tac2-/- mice parallel humans harboring NKB pathway mutations, with delayed sexual maturation and activation of the reproductive cascade later in life. Moreover, direct comparison of NKB ligand and receptor-deficient females confirmed that only NKB ligand-deficient animals have delayed sexual maturation, suggesting that in the absence of the NKB receptor, NKB may regulate the timing of sexual maturation through other tachykinin receptors.

  16. Timing and extent of response in colorectal cancer: critical review of current data and implication for future trials

    PubMed Central

    Aprile, Giuseppe; Fontanella, Caterina; Bonotto, Marta; Rihawi, Karim; Lutrino, Stefania Eufemia; Ferrari, Laura; Casagrande, Mariaelena; Ongaro, Elena; Berretta, Massimiliano; Avallone, Antonio; Rosati, Gerardo; Giuliani, Francesco; Fasola, Gianpiero

    2015-01-01

    The identification of new surrogate endpoints for advanced colorectal cancer is becoming crucial and, along with drug development, it represents a research field increasingly studied. Although overall survival (OS) remains the strongest trial endpoint available, it requires larger sample size and longer periods of time for an event to happen. Surrogate endpoints such as progression free survival (PFS) or response rate (RR) may overcome these issues but, as such, they need to be prospectively validated before replacing the real endpoints; moreover, they often bear many other limitations. In this narrative review we initially discuss the role of time-to-event endpoints, objective response and response rate as surrogates of OS in the advanced colorectal cancer setting, discussing also how such measures are influenced by the tumor assessment criteria currently employed. We then report recent data published about early tumor shrinkage and deepness of response, which have recently emerged as novel potential endpoint surrogates, discussing their strengths and weaknesses and providing a critical comment. Despite being very compelling, the role of such novel response measures is yet to be confirmed and their surrogacy with OS still needs to be further investigated within larger and well-designed trials. PMID:26308250

  17. Timing and extent of response in colorectal cancer: critical review of current data and implication for future trials.

    PubMed

    Aprile, Giuseppe; Fontanella, Caterina; Bonotto, Marta; Rihawi, Karim; Lutrino, Stefania Eufemia; Ferrari, Laura; Casagrande, Mariaelena; Ongaro, Elena; Berretta, Massimiliano; Avallone, Antonio; Rosati, Gerardo; Giuliani, Francesco; Fasola, Gianpiero

    2015-10-01

    The identification of new surrogate endpoints for advanced colorectal cancer is becoming crucial and, along with drug development, it represents a research field increasingly studied. Although overall survival (OS) remains the strongest trial endpoint available, it requires larger sample size and longer periods of time for an event to happen. Surrogate endpoints such as progression free survival (PFS) or response rate (RR) may overcome these issues but, as such, they need to be prospectively validated before replacing the real endpoints; moreover, they often bear many other limitations. In this narrative review we initially discuss the role of time-to-event endpoints, objective response and response rate as surrogates of OS in the advanced colorectal cancer setting, discussing also how such measures are influenced by the tumor assessment criteria currently employed. We then report recent data published about early tumor shrinkage and deepness of response, which have recently emerged as novel potential endpoint surrogates, discussing their strengths and weaknesses and providing a critical comment. Despite being very compelling, the role of such novel response measures is yet to be confirmed and their surrogacy with OS still needs to be further investigated within larger and well-designed trials. PMID:26308250

  18. The Relationship between Critical Thinking Abilities, Dispositional Traits, and the Career States of Part-Time Adult Learners.

    ERIC Educational Resources Information Center

    Duffy, Jean Ann

    2000-01-01

    Continuing education students (n=73) identified their career state and completed the Watson-Glaser Critical Thinking Appraisal and California Critical Thinking Disposition Inventory. Most were at career plateau or indecision stages. The ability to recognize assumptions, appraise situations, and make judgments was related to career state. (SK)

  19. Addressing critical environmental data gaps via low-cost, real-time, cellular-based environmental monitoring

    NASA Astrophysics Data System (ADS)

    Caylor, K. K.; Wolf, A.; Siegfried, B.

    2014-12-01

    Models in the environmental sciences are repositories in a sense of the current state of understanding of critical processes. However, as our understanding of these processes (and their accompanying models) become more granular, the data requirements to parameterize them become more limiting. In addition, as these models become more useful, they are often pressed into service for decision support, meaning that they cannot accept the data latency typical of most environmental observations. Finally, the vast majority of environmental data is generated at highly-instrumented, infrastructure-rich "mega sites" in the US/Europe, while many of the most pressing environmental issues are in rural locales and in the developing world. Cellular-based environmental sensing is a promising means to provide granular data in real time from remote locales to improve model-based forecasting using data assimilation. Applications we are working on include drought forecasting and food security; forest and crop responses to weather and climate change; and rural water usage. Over the past two years, we have developed a suite of integrated hardware, firmware, and backend APIs that accommodates an unlimited variety of sensors, and propagates these data onto the internet over mobile networks. Scientific data holds a unique role for demanding well-characterized information on sensor error and our design attempts to balance error reduction with low costs. The result is a deployment system that undercuts competing commercial products by as much as 90%, allowing more ubiquitous deployment with lower risks associated with sensor loss. Enclosure design and power management are critical ingredients for remote deployments under variable environmental conditions. Sensors push data onto cloud storage and make this data available via public API's via a backend server that accommodates additional metadata essential for interpreting observations, particularly their measurement errors. The data these pods

  20. Strength training increases endurance time to exhaustion during high-intensity exercise despite no change in critical power.

    PubMed

    Sawyer, Brandon J; Stokes, David G; Womack, Christopher J; Morton, R Hugh; Weltman, Arthur; Gaesser, Glenn A

    2014-03-01

    The purpose of this study was to determine whether improvements in endurance exercise performance elicited by strength training were accurately reflected by changes in parameters of the power-duration hyperbola for high-intensity exercise. Before and after 8 weeks of strength training (N = 14) or no exercise, control (N = 5), 19 males (age: 20.6 ± 2.0 years; weight: 78.2 ± 15.9 kg) performed a maximal incremental exercise test on a cycle ergometer and also cycled to exhaustion during 4 constant-power exercise bouts. Critical power (CP) and anaerobic work capacity (W') were estimated using nonlinear and linear models. Subjects in the strength training group improved significantly more than controls (p < 0.05) for strength (~30%), power at V[Combining Dot Above]O2peak (7.9%), and time to exhaustion (TTE) for all 4 constant-power tests (~39%). Contrary to our hypothesis, CP did not change significantly after strength training (p > 0.05 for all models). Strength training improved W' (mean range of improvement = +5.8 to +10.0 kJ; p < 0.05) for both linear models. Increases in W' were consistently positively correlated with improvements in TTE, whereas changes in CP were not. Our findings indicate that strength training alters the power-duration hyperbola such that W' is enhanced without any improvement in CP. Consequently, CP may not be robust enough to track changes in endurance capacity elicited by strength training, and we do not recommend it to be used for this purpose. Conversely, W' may be the better indicator of improvement in endurance performance elicited by strength training.

  1. Critical Length Criterion and the Arc Chain Model for Calculating the Arcing Time of the Secondary Arc Related to AC Transmission Lines

    NASA Astrophysics Data System (ADS)

    Cong, Haoxi; Li, Qingmin; Xing, Jinyuan; Li, Jinsong; Chen, Qiang

    2015-06-01

    The prompt extinction of the secondary arc is critical to the single-phase reclosing of AC transmission lines, including half-wavelength power transmission lines. In this paper, a low-voltage physical experimental platform was established and the motion process of the secondary arc was recorded by a high-speed camera. It was found that the arcing time of the secondary arc rendered a close relationship with its arc length. Through the input and output power energy analysis of the secondary arc, a new critical length criterion for the arcing time was proposed. The arc chain model was then adopted to calculate the arcing time with both the traditional and the proposed critical length criteria, and the simulation results were compared with the experimental data. The study showed that the arcing time calculated from the new critical length criterion gave more accurate results, which can provide a reliable criterion in term of arcing time for modeling and simulation of the secondary arc related with power transmission lines. supported by National Natural Science Foundation of China (Nos. 51277061 and 51420105011)

  2. Part-Time Learners in Open and Distance Learning: Revisiting the Critical Importance of Choice, Flexibility and Employability

    ERIC Educational Resources Information Center

    Butcher, John; Rose-Adams, John

    2015-01-01

    In this article, we argue that, if open learning seeks to (re)assert a social justice mission, issues of openness and flexibility are more critical than ever. Drawing on qualitative data from a National Union of Students Wales/Open University study, which explored, in the voices of Welsh students, the identity, motivation and barriers faced by…

  3. MeCP2 regulates the timing of critical period plasticity that shapes functional connectivity in primary visual cortex.

    PubMed

    Krishnan, Keerthi; Wang, Bor-Shuen; Lu, Jiangteng; Wang, Lang; Maffei, Arianna; Cang, Jianhua; Huang, Z Josh

    2015-08-25

    Mutations in methyl-CpG-binding protein 2 (MeCP2) cause Rett syndrome, an autism spectrum-associated disorder with a host of neurological and sensory symptoms, but the pathogenic mechanisms remain elusive. Neuronal circuits are shaped by experience during critical periods of heightened plasticity. The maturation of cortical GABA inhibitory circuitry, the parvalbumin(+) (PV(+)) fast-spiking interneurons in particular, is a key component that regulates the initiation and termination of the critical period. Using MeCP2-null mice, we examined experience-dependent development of neural circuits in the primary visual cortex. The functional maturation of parvalbumin interneurons was accelerated upon vision onset, as indicated by elevated GABA synthetic enzymes, vesicular GABA transporter, perineuronal nets, and enhanced GABA transmission among PV interneurons. These changes correlated with a precocious onset and closure of critical period and deficient binocular visual function in mature animals. Reduction of GAD67 expression rescued the precocious opening of the critical period, suggesting its major role in MECP2-mediated regulation of experience-driven circuit development. Our results identify molecular changes in a defined cortical cell type and link aberrant developmental trajectory to functional deficits in a model of neuropsychiatric disorder.

  4. MeCP2 regulates the timing of critical period plasticity that shapes functional connectivity in primary visual cortex

    PubMed Central

    Krishnan, Keerthi; Wang, Bor-Shuen; Lu, Jiangteng; Wang, Lang; Maffei, Arianna; Cang, Jianhua; Huang, Z. Josh

    2015-01-01

    Mutations in methyl-CpG-binding protein 2 (MeCP2) cause Rett syndrome, an autism spectrum-associated disorder with a host of neurological and sensory symptoms, but the pathogenic mechanisms remain elusive. Neuronal circuits are shaped by experience during critical periods of heightened plasticity. The maturation of cortical GABA inhibitory circuitry, the parvalbumin+ (PV+) fast-spiking interneurons in particular, is a key component that regulates the initiation and termination of the critical period. Using MeCP2-null mice, we examined experience-dependent development of neural circuits in the primary visual cortex. The functional maturation of parvalbumin interneurons was accelerated upon vision onset, as indicated by elevated GABA synthetic enzymes, vesicular GABA transporter, perineuronal nets, and enhanced GABA transmission among PV interneurons. These changes correlated with a precocious onset and closure of critical period and deficient binocular visual function in mature animals. Reduction of GAD67 expression rescued the precocious opening of the critical period, suggesting its major role in MECP2-mediated regulation of experience-driven circuit development. Our results identify molecular changes in a defined cortical cell type and link aberrant developmental trajectory to functional deficits in a model of neuropsychiatric disorder. PMID:26261347

  5. A Critical Challenge: The Engagement and Assessment of Contingent, Part-Time Adjunct Faculty Professors in United States Community Colleges

    ERIC Educational Resources Information Center

    Jolley, Michael R.; Cross, Emily; Bryant, Miles

    2014-01-01

    In 2011, according to a National Center for Education Statistics report, part-time instructional staff in all higher education institutions exceeded full-time faculty members for the first time, accounting for 50% of all instructional staff (National Center for Education Statistics [NCES], 2012). The same report indicates part-time faculty in…

  6. Investigating critical effects of variegated lubricants, glidants and hydrophilic additives on lag time of press coated ethylcellulose tablets.

    PubMed

    Patadia, Riddhish; Vora, Chintan; Mittal, Karan; Mashru, Rajashree

    2016-01-01

    The research envisaged focuses on vital impacts of variegated lubricants, glidants and hydrophilic additives on lag time of press coated ethylcellulose (EC) tablets using prednisone as a model drug. Several lubricants and glidants such as magnesium stearate, colloidal SiO2, sodium stearyl fumarate, talc, stearic acid, polyethylene glycol (6000) and glyceryl behenate were investigated to understand their effects on lag time by changing their concentrations in outer coat. Further, the effects of hydrophilic additives on lag time were examined for hydroxypropylmethylcellulose (E5), hydroxypropylcellulose (EF and SSL), povidone (K30), copovidone, polyethylene glycol (4000), lactose and mannitol. In vitro drug release testing revealed that each selected lubricant/glidant, if present even at concentration of 0.25% w/w, significantly reduced the lag time of press coated tablets. Specifically, colloidal SiO2 and/or magnesium stearate were detrimental while other lubricants/glidants were relatively less injurious. Among hydrophilic additives, freely water soluble fillers had utmost influence in lag time, whereas, comparatively less impact was observed with polymeric binders. Concisely, glidant and lubricant should be chosen to have minimal impact on lag time and further judicious selection of hydrophilic additives should be exercised for modulating lag time of pulsatile release formulations.

  7. Ebola Virus Disease: Rapid Diagnosis and Timely Case Reporting are Critical to the Early Response for Outbreak Control

    PubMed Central

    Stamm, Lola V.

    2015-01-01

    Ebola virus disease (EVD) is a life-threatening zoonosis caused by infection with the Ebola virus. Since the first reported EVD outbreak in the Democratic Republic of the Congo, several small outbreaks have been reported in central Africa with about 2,400 cases occurring between 1976 and 2013. The 2013–2015 EVD outbreak in west Africa is the first documented outbreak in this region and the largest ever with over 27,000 cases and more than 11,000 deaths. Although EVD transmission rates have recently decreased in west Africa, this crisis continues to threaten global health and security, particularly since infected travelers could spread EVD to other resource-limited areas of the world. Because vaccines and drugs are not yet licensed for EVD, outbreak control is dependent on the use of non-pharmaceutical interventions (e.g., infection control practices, isolation of EVD cases, contact tracing with follow-up and quarantine, sanitary burial, health education). However, delays in diagnosing and reporting EVD cases in less accessible rural areas continue to hamper control efforts. New advances in rapid diagnostics for identifying presumptive EVD cases and in mobile-based technologies for communicating critical health-related information should facilitate deployment of an early response to prevent the amplification of sporadic EVD cases into large-scale outbreaks. PMID:26175026

  8. Dead-time correction for time-of-flight secondary-ion mass spectral images: a critical issue in multivariate image analysis.

    PubMed

    Tyler, Bonnie J; Peterson, Richard E

    2013-01-01

    Dead-time effects result in a non-linear detector response in the common time-of-flight secondary-ion mass spectrometry instruments. This can result in image artifacts that can often be misinterpreted. Although the Poisson correction procedure has been shown to effectively eliminate this non-linearity in spectra, applying the correction to images presents difficulties because the low number of counts per pixel can create large statistical errors. The efficacy of three approaches to dead-time correction in images has been explored. These approaches include: pixel binning, image segmentation and a binomial statistical correction. When few pixels are fully saturated, all three approaches work satisfactorily. When a large number of pixels are fully saturated, the statistical approach fails to remove the dead-time artifacts revealed by multivariate analysis. Pixel binning is accurate at higher levels of saturation so long as the bin size is much smaller than the feature size. The segmentation approach works well independent of feature size or the number of fully saturated pixels but requires an accurate segmentation algorithm. It is recommended that images be collected under conditions that minimize the number of fully saturated pixels. When this is impractical and small features are present in the image, segmentation can provide an accurate way to correct for the detector saturation effect. PMID:24707067

  9. "I Just Didn't Have Enough Time..." Assisting the Busy Adult Learner Develop Critical Reading and Thinking Skills.

    ERIC Educational Resources Information Center

    Diaz-Lefebvre, Rene

    Several factors are related to adult students' completion or noncompletion of reading assignments before class--lack of study time, their motivation for taking college classes, their need to feel involved in the learning process, and their expectations for success in the classroom. One of the biggest fears of adults returning to a school…

  10. Utilizing Social Networks in Times of Crisis: Understanding, Exploring and Analyzing Critical Incident Management at Institutions of Higher Education

    ERIC Educational Resources Information Center

    Asselin, Martha Jo

    2012-01-01

    With the rising number of major crises on college campuses today (Security on Campus Inc., 2009), institutions of higher education can benefit from understanding of how social networks may be used in times of emergency. What is currently known about the usage of social networks is not integral to the current practices of crisis management that are…

  11. Design, Development and Evaluation of Collaborative Team Training Method in Virtual Worlds for Time-Critical Medical Procedures

    ERIC Educational Resources Information Center

    Khanal, Prabal

    2014-01-01

    Medical students acquire and enhance their clinical skills using various available techniques and resources. As the health care profession has move towards team-based practice, students and trainees need to practice team-based procedures that involve timely management of clinical tasks and adequate communication with other members of the team.…

  12. Act Fast as Time Is Less: High Faecal Carriage of Carbapenem-Resistant Enterobacteriaceae in Critical Care Patients

    PubMed Central

    Sahu, Manisa; Pathrose, Edwin Joseph; Shivdas, Sarita

    2016-01-01

    Introduction Carbapenem-resistant Enterobacteriaceae (CRE) are drug-resistant Gram-negative bacteria that are present in the community as well as in hospitals. Their infection and colonisation puts critically ill patients at high risk due to the drug-resistant nature of the strains and possible spreading of these organisms, even in a hospital environment. Aim To examine the presence and types of Enterobacteriaceae species in patients admitted directly from the community. Materials and Methods The present study was a one-month pilot conducted in the ICU of a tertiary care hospital in Mumbai, India in 2015. Faecal samples of patients admitted from the community directly to the ICU were analysed using tests like MHT (Modified Hodge) and EDTA for the presence of IMP (action on Imipenem) and KPC (Klebsiella Test Pneumoniae Carbapenemase) producing strains of Enterobacteriaceae. Polymerase Chain Reaction (PCR) was performed to look for VIM, IMP, NDM1, OXA, and KPC genes. Antibiotic Sensitivity Test was carried out as per CLSI guidelines. Results The results showed an alarming level of faecal carriage rates in adult ICU patients. Klebsiella pneumonia was the most common carbapenem-resistant isolate, closely followed by Escherichia coli. PCR results revealed nine strains were positive for bla(KPC) gene, from which 7 were Klebsiella pneumoniae and one each of Escherichia coli and Klebsiella oxytoca was observed. Antibiotic Sensitivity Test results showed that the isolates had maximum sensitivity to Colistin (100%) and Tigecycline (95%). Conclusion These levels indicate that in the absence of CRE screenings, proper isolation of carrier patients is not possible, leading to possible spreading of these resistant bacteria strains in ICUs. A longer period of study is required to obtain more substantial data to validate the results of this pilot. PMID:27790429

  13. Healthcare Disparities in Critical Illness

    PubMed Central

    Soto, Graciela J.; Martin, Greg S.; Gong, Michelle Ng

    2013-01-01

    Objective To summarize the current literature on racial and gender disparities in critical care and the mechanisms underlying these disparities in the course of acute critical illness. Data Sources MEDLINE search on the published literature addressing racial, ethnic, or gender disparities in acute critical illness such as sepsis, acute lung injury, pneumonia, venous thromboembolism, and cardiac arrest. Study Selection Clinical studies that evaluated general critically ill patient populations in the United States as well as specific critical care conditions were reviewed with a focus on studies evaluating factors and contributors to health disparities. Data Extraction Study findings are presented according to their association with the incidence, clinical presentation, management, and outcomes in acute critical illness. Data Synthesis This review presents potential contributors for racial and gender disparities related to genetic susceptibility, comorbidities, preventive health services, socioeconomic factors, cultural differences, and access to care. The data is organized along the course of acute critical illness. Conclusions The literature to date shows that disparities in critical care are most likely multifactorial involving individual, community, and hospital-level factors at several points in the continuum of acute critical illness. The data presented identify potential targets as interventions to reduce disparities in critical care and future avenues for research. PMID:24121467

  14. Time and Demand are Two Critical Dimensions of Immunometabolism: The Process of Macrophage Activation and the Pentose Phosphate Pathway.

    PubMed

    Nagy, Csörsz; Haschemi, Arvand

    2015-01-01

    A process is a function of time; in immunometabolism, this is reflected by the stepwise adaptation of metabolism to sustain the bio-energetic demand of an immune-response in its various states and shades. This perspective article starts by presenting an early attempt to investigate the physiology of inflammation, in order to illustrate one of the basic concepts of immunometabolism, wherein an adapted metabolism of infiltrating immune cells affects tissue function and inflammation. We then focus on the process of macrophage activation and aim to delineate the factor time within the current molecular context of metabolic-rewiring important for adapting primary carbohydrate metabolism. In the last section, we will provide information on how the pentose phosphate pathway may be of importance to provide both nucleotide precursors and redox-equivalents, and speculate how carbon-scrambling events in the non-oxidative pentose phosphate pathway might be regulated within cells by demand. We conclude that the adapted metabolism of inflammation is specific in respect to the effector-function and appears as a well-orchestrated event, dynamic by nature, and based on a functional interplay of signaling- and metabolic-pathways.

  15. Critical elements in implementations of just-in-time management: empirical study of cement industry in Pakistan.

    PubMed

    Qureshi, Muhammad Imran; Iftikhar, Mehwish; Bhatti, Mansoor Nazir; Shams, Tauqeer; Zaman, Khalid

    2013-01-01

    In recent years, inventory management is continuous challenge for all organizations not only due to heavy cost associated with inventory holding, but also it has a great deal to do with the organizations production process. Cement industry is a growing sector of Pakistan's economy which is now facing problems in capacity utilization of their plants. This study attempts to identify the key strategies for successful implementation of just-in-time (JIT) management philosophy on the cement industry of Pakistan. The study uses survey responses from four hundred operations' managers of cement industry in order to know about the advantages and benefits that cement industry have experienced by Just in time (JIT) adoption. The results show that implementing the quality, product design, inventory management, supply chain and production plans embodied through the JIT philosophy which infect enhances cement industry competitiveness in Pakistan. JIT implementation increases performance by lower level of inventory, reduced operations & inventory costs was reduced eliminates wastage from the processes and reduced unnecessary production which is a big challenge for the manufacturer who are trying to maintain the continuous flow processes. JIT implementation is a vital manufacturing strategy that reaches capacity utilization and minimizes the rate of defect in continuous flow processes. The study emphasize the need for top management commitment in order to incorporate the necessary changes that need to take place in cement industry so that JIT implementation can take place in an effective manner. PMID:24340248

  16. Critical factors determining the quantification capability of matrix-assisted laser desorption/ionization- time-of-flight mass spectrometry.

    PubMed

    Wang, Chia-Chen; Lai, Yin-Hung; Ou, Yu-Meng; Chang, Huan-Tsung; Wang, Yi-Sheng

    2016-10-28

    Quantitative analysis with mass spectrometry (MS) is important but challenging. Matrix-assisted laser desorption/ionization (MALDI) coupled with time-of-flight (TOF) MS offers superior sensitivity, resolution and speed, but such techniques have numerous disadvantages that hinder quantitative analyses. This review summarizes essential obstacles to analyte quantification with MALDI-TOF MS, including the complex ionization mechanism of MALDI, sensitive characteristics of the applied electric fields and the mass-dependent detection efficiency of ion detectors. General quantitative ionization and desorption interpretations of ion production are described. Important instrument parameters and available methods of MALDI-TOF MS used for quantitative analysis are also reviewed.This article is part of the themed issue 'Quantitative mass spectrometry'.

  17. Critical factors determining the quantification capability of matrix-assisted laser desorption/ionization- time-of-flight mass spectrometry.

    PubMed

    Wang, Chia-Chen; Lai, Yin-Hung; Ou, Yu-Meng; Chang, Huan-Tsung; Wang, Yi-Sheng

    2016-10-28

    Quantitative analysis with mass spectrometry (MS) is important but challenging. Matrix-assisted laser desorption/ionization (MALDI) coupled with time-of-flight (TOF) MS offers superior sensitivity, resolution and speed, but such techniques have numerous disadvantages that hinder quantitative analyses. This review summarizes essential obstacles to analyte quantification with MALDI-TOF MS, including the complex ionization mechanism of MALDI, sensitive characteristics of the applied electric fields and the mass-dependent detection efficiency of ion detectors. General quantitative ionization and desorption interpretations of ion production are described. Important instrument parameters and available methods of MALDI-TOF MS used for quantitative analysis are also reviewed.This article is part of the themed issue 'Quantitative mass spectrometry'. PMID:27644968

  18. Inhibition of mitochondrial fission as a molecular target for cardioprotection: critical importance of the timing of treatment.

    PubMed

    Dong, Yi; Undyala, Vishnu V R; Przyklenk, Karin

    2016-09-01

    Recent attention has focused on the concept that mitochondrial dynamics-that is, the balance between mitochondrial fusion and fission (fragmentation)-may play a pivotal role in determining cell fate in the setting of myocardial ischemia-reperfusion injury. In this regard, there is an emerging consensus that: (1) ischemia-reperfusion favors mitochondrial fragmentation and (2) strategies aimed at inhibiting the translocation of dynamin-related protein 1 (DRP1: the 'master regulator' of fission) from the cytosol to the mitochondria, when initiated as a pretreatment, are cardioprotective. However, direct molecular evidence of a cause-and-effect relationship between mitochondrial fission and cardiomyocyte death has not been established. To address this issue, we used a well-characterized in vitro, immortal cultured cardiomyocyte model to establish whether subcellular redistribution of DRP1 to mitochondria: (1) is triggered by hypoxia-reoxygenation; (2) plays a causal role in hypoxia-reoxygenation-induced cytochrome c release (harbinger of apoptosis) and cardiomyocyte death; and (3) represents a molecular mechanism that can be targeted in a clinically relevant time frame to render cells resistant to lethal hypoxia-reoxygenation injury. Our results provide direct evidence that the redistribution of DRP1 to mitochondria contributes to cardiomyocyte death, and corroborate the previous observations that the pre-ischemic inhibition of DRP1 translocation is cardioprotective. Moreover, we report the novel finding that-in marked contrast to the data obtained with pretreatment-inhibition of DRP1 translocation initiated at the time of reoxygenation had complex, unexpected and unfavorable consequences: i.e., attenuated cardiomyocyte apoptosis but exacerbated total cell death, possibly via concurrent upregulation of necroptosis. PMID:27573530

  19. Time to Give Up on Cardioprotection? A Critical Appraisal of Clinical Studies on Ischemic Pre-, Post-, and Remote Conditioning.

    PubMed

    Heusch, Gerd; Rassaf, Tienush

    2016-08-19

    The mortality from acute myocardial infarction (AMI) remains significant, and the prevalence of post-myocardial infarction heart failure is increasing. Therefore, cardioprotection beyond timely reperfusion is needed. Conditioning procedures are the most powerful cardioprotective interventions in animal experiments. However, ischemic preconditioning cannot be used to reduce infarct size in patients with AMI because its occurrence is not predictable; several studies in patients undergoing surgical coronary revascularization report reduced release of creatine kinase and troponin. Ischemic postconditioning reduces infarct size in most, but not all, studies in patients undergoing interventional reperfusion of AMI, but may require direct stenting and exclusion of patients with >6 hours of symptom onset to protect. Remote ischemic conditioning reduces infarct size in patients undergoing interventional reperfusion of AMI, elective percutaneous or surgical coronary revascularization, and other cardiovascular surgery in many, but not in all, studies. Adequate dose-finding phase II studies do not exist. There are only 2 phase III trials, both on remote ischemic conditioning in patients undergoing cardiovascular surgery, both with neutral results in terms of infarct size and clinical outcome, but also both with major problems in trial design. We discuss the difficulties in translation of cardioprotection from animal experiments and proof-of-concept trials to clinical practice. Given that most studies on ischemic postconditioning and all studies on remote ischemic preconditioning in patients with AMI reported reduced infarct size, it would be premature to give up on cardioprotection. PMID:27539973

  20. A complexity basis for phenomenology: How information states at criticality offer a new approach to understanding experience of self, being and time.

    PubMed

    Hankey, Alex

    2015-12-01

    In the late 19th century Husserl studied our internal sense of time passing, maintaining that its deep connections into experience represent prima facie evidence for it as the basis for all investigations in the sciences: Phenomenology was born. Merleau-Ponty focused on perception pointing out that any theory of experience must accord with established aspects of biology i.e. be embodied. Recent analyses suggest that theories of experience require non-reductive, integrative information, together with a specific property connecting them to experience. Here we elucidate a new class of information states with just such properties found at the loci of control of complex biological systems, including nervous systems. Complexity biology concerns states satisfying self-organized criticality. Such states are located at critical instabilities, commonly observed in biological systems, and thought to maximize information diversity and processing, and hence to optimize regulation. Major results for biology follow: why organisms have unusually low entropies; and why they are not merely mechanical. Criticality states form singular self-observing systems, which reduce wave packets by processes of perfect self-observation associated with feedback gain g = 1. Analysis of their information properties leads to identification of a new kind of information state with high levels of internal coherence, and feedback loops integrated into their structure. The major idea presented here is that the integrated feedback loops are responsible for our 'sense of self', and also the feeling of continuity in our sense of time passing. Long-range internal correlations guarantee a unique kind of non-reductive, integrative information structure enabling such states to naturally support phenomenal experience. Being founded in complexity biology, they are 'embodied'; they also fulfill the statement that 'The self is a process', a singular process. High internal correlations and René Thom

  1. A complexity basis for phenomenology: How information states at criticality offer a new approach to understanding experience of self, being and time.

    PubMed

    Hankey, Alex

    2015-12-01

    In the late 19th century Husserl studied our internal sense of time passing, maintaining that its deep connections into experience represent prima facie evidence for it as the basis for all investigations in the sciences: Phenomenology was born. Merleau-Ponty focused on perception pointing out that any theory of experience must accord with established aspects of biology i.e. be embodied. Recent analyses suggest that theories of experience require non-reductive, integrative information, together with a specific property connecting them to experience. Here we elucidate a new class of information states with just such properties found at the loci of control of complex biological systems, including nervous systems. Complexity biology concerns states satisfying self-organized criticality. Such states are located at critical instabilities, commonly observed in biological systems, and thought to maximize information diversity and processing, and hence to optimize regulation. Major results for biology follow: why organisms have unusually low entropies; and why they are not merely mechanical. Criticality states form singular self-observing systems, which reduce wave packets by processes of perfect self-observation associated with feedback gain g = 1. Analysis of their information properties leads to identification of a new kind of information state with high levels of internal coherence, and feedback loops integrated into their structure. The major idea presented here is that the integrated feedback loops are responsible for our 'sense of self', and also the feeling of continuity in our sense of time passing. Long-range internal correlations guarantee a unique kind of non-reductive, integrative information structure enabling such states to naturally support phenomenal experience. Being founded in complexity biology, they are 'embodied'; they also fulfill the statement that 'The self is a process', a singular process. High internal correlations and René Thom

  2. Molecular and morphological phylogenetics of chelonine parasitoid wasps (Hymenoptera: Braconidae), with a critical assessment of divergence time estimations.

    PubMed

    Kittel, Rebecca N; Austin, Andrew D; Klopfstein, Seraina

    2016-08-01

    Parasitoid wasps of the subfamily Cheloninae are both species rich and poorly known. Although the taxonomy of Cheloninae appears to be relatively stable, there is no clear understanding of relationships among higher-level taxa. We here applied molecular phylogenetic analyses using three markers (COI, EF1α, 28S) and 37 morphological characters to elucidate the evolution and systematics of these wasps. Analyses were based on 83 specimens representing 13 genera. All genera except Ascogaster, Phanerotoma, and Pseudophanerotoma formed monophyletic groups; Furcidentia (stat. rev.) is raised to generic rank. Neither Chelonus (Chelonus) nor Chelonus (Microchelonus) were recovered as monophyletic, but together formed a monophyletic lineage. The tribes Chelonini and Odontosphaeropygini formed monophyletic groups, but the Phanerotomini sensu Zettel and Pseudophanerotomini were retrieved as either para- or polyphyletic. The genera comprising the former subfamily Adeliinae were confirmed as being nested within the Cheloninae. To estimate the age of the subfamily, we used 16 fossil taxa. Three approaches were compared: fixed-rate dating, node dating, and total-evidence dating, with age estimates differing greatly between the three methods. Shortcomings of each approach in relation to our dataset are discussed, and none of the age estimates is deemed sufficiently reliable. Given that most dating studies use a single method only, in most cases without presenting analyses on the sensitivity to priors, it is likely that numerous age estimates in the literature suffer from a similar lack of robustness. We argue for a more rigorous approach to dating analyses and for a faithful presentation of uncertainties in divergence time estimates. Given the results of the phylogenetic analysis the following taxonomic changes are proposed: Furcidentia Zettel (stat. rev.), previously treated as a subgenus of Pseudophanerotoma Zettel is raised to generic rank; Microchelonus Szépligeti (syn. nov

  3. Molecular and morphological phylogenetics of chelonine parasitoid wasps (Hymenoptera: Braconidae), with a critical assessment of divergence time estimations.

    PubMed

    Kittel, Rebecca N; Austin, Andrew D; Klopfstein, Seraina

    2016-08-01

    Parasitoid wasps of the subfamily Cheloninae are both species rich and poorly known. Although the taxonomy of Cheloninae appears to be relatively stable, there is no clear understanding of relationships among higher-level taxa. We here applied molecular phylogenetic analyses using three markers (COI, EF1α, 28S) and 37 morphological characters to elucidate the evolution and systematics of these wasps. Analyses were based on 83 specimens representing 13 genera. All genera except Ascogaster, Phanerotoma, and Pseudophanerotoma formed monophyletic groups; Furcidentia (stat. rev.) is raised to generic rank. Neither Chelonus (Chelonus) nor Chelonus (Microchelonus) were recovered as monophyletic, but together formed a monophyletic lineage. The tribes Chelonini and Odontosphaeropygini formed monophyletic groups, but the Phanerotomini sensu Zettel and Pseudophanerotomini were retrieved as either para- or polyphyletic. The genera comprising the former subfamily Adeliinae were confirmed as being nested within the Cheloninae. To estimate the age of the subfamily, we used 16 fossil taxa. Three approaches were compared: fixed-rate dating, node dating, and total-evidence dating, with age estimates differing greatly between the three methods. Shortcomings of each approach in relation to our dataset are discussed, and none of the age estimates is deemed sufficiently reliable. Given that most dating studies use a single method only, in most cases without presenting analyses on the sensitivity to priors, it is likely that numerous age estimates in the literature suffer from a similar lack of robustness. We argue for a more rigorous approach to dating analyses and for a faithful presentation of uncertainties in divergence time estimates. Given the results of the phylogenetic analysis the following taxonomic changes are proposed: Furcidentia Zettel (stat. rev.), previously treated as a subgenus of Pseudophanerotoma Zettel is raised to generic rank; Microchelonus Szépligeti (syn. nov

  4. The role of a critical time intervention on the experience of continuity of care among persons with severe mental illness after hospital discharge.

    PubMed

    Tomita, Andrew; Herman, Daniel B

    2015-01-01

    We investigated the impact of critical time intervention (CTI) on self-reported indicators of quality of continuity of care (COC) after discharge from inpatient psychiatric treatment with data from a randomized controlled trial that assessed the effectiveness of the intervention in reducing recurrent homelessness. Postdischarge COC outcome measures among previously homeless persons with severe mental illness randomly assigned to receive usual services only (n = 73) or 9 months of CTI in addition to usual services (n = 77) were compared. Those assigned to CTI had greater perceived access to care than the usual services group did, with this impact extending beyond the point at which the intervention ended. A time-limited care coordination intervention provided immediately after hospital discharge may improve COC, but further studies are needed to substantiate an effect of CTI on long-term continuity outcomes.

  5. Phase transitions and critical phenomena in the two-dimensional Ising model with dipole interactions: A short-time dynamics study.

    PubMed

    Horowitz, C M; Bab, M A; Mazzini, M; Rubio Puzzo, M L; Saracco, G P

    2015-10-01

    The ferromagnetic Ising model with antiferromagnetic dipole interactions is investigated by means of Monte Carlo simulations, focusing on the characterization of the phase transitions between the tetragonal liquid and stripe of width h phases. The dynamic evolution of the physical observables is analyzed within the short-time regime for 0.5≤δ≤1.3, where δ is the ratio between the short-range exchange and the long-range dipole interaction constants. The obtained results for the interval 0.5≤δ≤1.2 indicate that the phase transition line between the h=1 stripe and tetragonal liquid phases is continuous. This finding contributes to clarifying the controversy about the order of this transition. This controversy arises from the difficulties introduced in the simulations due to the presence of long-range dipole interactions, such as an important increase in the simulation times that limits the system size used, strong finite size effects, as well as to the existence of multiple metastable states at low temperatures. The study of the short-time dynamics of the model allows us to avoid these hindrances. Moreover, due to the fact that the finite-size effects do not significantly affect the power-law behavior exhibited in the observables within the short-time regime, the results could be attributed to those corresponding to the thermodynamic limit. As a consequence of this, a careful characterization of the critical behavior for the whole transition line is performed by giving the complete set of critical exponents.

  6. Time-critical social mobilization.

    PubMed

    Pickard, Galen; Pan, Wei; Rahwan, Iyad; Cebrian, Manuel; Crane, Riley; Madan, Anmol; Pentland, Alex

    2011-10-28

    The World Wide Web is commonly seen as a platform that can harness the collective abilities of large numbers of people to accomplish tasks with unprecedented speed, accuracy, and scale. To explore the Web's ability for social mobilization, the Defense Advanced Research Projects Agency (DARPA) held the DARPA Network Challenge, in which competing teams were asked to locate 10 red weather balloons placed at locations around the continental United States. Using a recursive incentive mechanism that both spread information about the task and incentivized individuals to act, our team was able to find all 10 balloons in less than 9 hours, thus winning the Challenge. We analyzed the theoretical and practical properties of this mechanism and compared it with other approaches.

  7. Testing the Critical Window Hypothesis of Timing and Duration of Estradiol Treatment on Hypothalamic Gene Networks in Reproductively Mature and Aging Female Rats

    PubMed Central

    Yin, Weiling; Maguire, Sean M.; Pham, Brian; Garcia, Alexandra N.; Dang, Nguyen-Vy; Liang, Jingya; Wolfe, Andrew; Hofmann, Hans A.

    2015-01-01

    At menopause, the dramatic loss of ovarian estradiol (E2) necessitates the adaptation of estrogen-sensitive neurons in the hypothalamus to an estrogen-depleted environment. We developed a rat model to test the “critical window” hypothesis of the effects of timing and duration of E2 treatment after deprivation on the hypothalamic neuronal gene network in the arcuate nucleus and the medial preoptic area. Rats at 2 ages (reproductively mature or aging) were ovariectomized and given E2 or vehicle replacement regimes of differing timing and duration. Using a 48-gene quantitative low-density PCR array and weighted gene coexpression network analysis, we identified gene modules differentially regulated by age, timing, and duration of E2 treatment. Of particular interest, E2 status differentially affected suites of genes in the hypothalamus involved in energy balance, circadian rhythms, and reproduction. In fact, E2 status was the dominant factor in determining gene modules and hormone levels; age, timing, and duration had more subtle effects. Our results highlight the plasticity of hypothalamic neuroendocrine systems during reproductive aging and its surprising ability to adapt to diverse E2 replacement regimes. PMID:26018250

  8. Dynamics of pulsed laser ablation plasmas in high-density CO2 near the critical point investigated by time-resolved shadowgraph imaging

    NASA Astrophysics Data System (ADS)

    Urabe, Keiichiro; Kato, Toru; Himeno, Shohei; Kato, Satoshi; Stauss, Sven; Baba, Motoyoshi; Suemoto, Tohru; Terashima, Kazuo

    2013-09-01

    Pulsed laser ablation (PLA) plasmas generated in high-density gases and liquids are promising for the synthesis of nanomaterials. However, the characteristics of such plasmas are still not well understood. In order to improve the understandings of PLA plasmas in high-density fluids including gases, liquids, and supercritical fluids (SCFs), we have investigated the dynamics of PLA plasmas in high-density carbon dioxide (CO2) . We report on experimental results of time-resolved shadowgraph imaging, from the generation of plasma plume to the extinction of cavitation bubbles. Shadowgraph images revealed that the PLA plasma dynamics showed two distinct behaviors. These are divided by gas-liquid coexistence curve and the so-called Widom line, which separates gas-like and liquid-like SCF domains. Furthermore, cavitation bubble observed in liquid CO2 near the critical point showed peculiar characteristics, the formation of an inner bubble and an outer shell structure, which so far has never been reported. The experiments indicate that thermophysical properties of PLA plasmas can be tuned by controlling solvent temperature and pressure around the critical point, which may be useful for materials processing. This work was supported financially in part by a Grant-in-Aid for Scientific Research on Innovative Areas (No. 21110002) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan.

  9. Thinking Critically about Critical Thinking

    ERIC Educational Resources Information Center

    Mulnix, Jennifer Wilson

    2012-01-01

    As a philosophy professor, one of my central goals is to teach students to think critically. However, one difficulty with determining whether critical thinking can be taught, or even measured, is that there is widespread disagreement over what critical thinking actually is. Here, I reflect on several conceptions of critical thinking, subjecting…

  10. Critical assumptions: thinking critically about critical thinking.

    PubMed

    Riddell, Thelma

    2007-03-01

    The concept of critical thinking has been featured in nursing literature for the past 20 years. It has been described but not defined by both the American Association of Colleges of Nursing and the National League for Nursing, although their corresponding accreditation bodies require that critical thinking be included in nursing curricula. In addition, there is no reliable or valid measurement tool for critical thinking ability in nursing. As a result, there is a lack of research support for the assumptions that critical thinking can be learned and that critical thinking ability improves clinical competence. Brookfield suggested that commitments should be made only after a period of critically reflective analysis, during which the congruence between perceptions and reality are examined. In an evidence-based practice profession, we, as nurse educators, need to ask ourselves how we can defend our assumptions that critical thinking can be learned and that critical thinking improves the quality of nursing practice, especially when there is virtually no consensus on a definition.

  11. Hillslope lowering rates and mobile-regolith residence times from in situ and meteoric 10Be analysis: Boulder Creek Critical Zone Observatory, Colorado

    NASA Astrophysics Data System (ADS)

    Foster, M. A.; Anderson, R. S.; Wyshnytzky, C.; Ouimet, W. B.; Dethier, D. P.

    2014-12-01

    Mobile regolith is produced as weathered saprolite is entrained into the mobile layer. The rate of mobile-regolith production and its residence time on hillslopes shapes the topography and evolution of hillslopes. We calculate the production rate of mobile regolith and the mobile-regolith residence times on active hillslopes in Gordon Gulch, within the Boulder Creek Critical Zone Observatory (CZO), Colorado. We find mobile-regolith production rates (average 3.1 cm/ka) and residence times (average 10-20 ka) derived from both in situand meteoric methods agree. Lowering-rates derived from our study are also comparable to basin-averaged denudation rates for small basins in the Colorado Front Range (Dethier and Lazarus, 2006). In this study, we have measured both in situ and meteoric 10Be in saprolite and mobile regolith separately. We find that, on average, two-thirds of in situ 10Be is produced within saprolite, and that at least one-tenth of the meteoric 10Be inventories are stored in saprolite. In the case of in situ 10Be, this simply reflects the exponential fall-off in production rates through a thin mobile-regolith cover. In the case of meteoric 10Be, our calculations suggest that >40% of the meteoric 10Be deposition occurs within the saprolite. Most studies that utilize 10Be report residence times and soil-production rates based on concentrations in either the mobile regolith or saprolite; therefore, our 10Be data highlight the importance of clearly identifying mobile and immobile portions of the regolith, constraining its 10Be inventory, and use of consistent terminology for the mobile-layer.

  12. Time?

    NASA Astrophysics Data System (ADS)

    Amoroso, Richard L.

    2013-09-01

    The concept of time in the `clockwork' Newtonian world was irrelevant; and has generally been ignored until recently by several generations of physicists since the implementation of quantum mechanics. We will set aside the utility of time as a property relating to physical calculations of events relating to a metrics line element or as an aspect of the transformation of a particles motion/interaction in a coordinate system or in relation to thermodynamics etc., i.e. we will discard all the usual uses of time as a concept used to circularly define physical parameters in terms of other physical parameters; concentrating instead on time as an aspect of the fundamental cosmic topology of our virtual reality especially as it inseparably relates to the nature and role of the observer in natural science.

  13. Assessment of critical exposure and outcome windows in time-to-event analysis with application to air pollution and preterm birth study.

    PubMed

    Chang, Howard H; Warren, Joshua L; Darrow, Lnydsey A; Reich, Brian J; Waller, Lance A

    2015-07-01

    In reproductive epidemiology, there is a growing interest to examine associations between air pollution exposure during pregnancy and the risk of preterm birth (PTB). One important research objective is to identify critical periods of exposure and estimate the associated effects at different stages of pregnancy. However, population studies have reported inconsistent findings. This may be due to limitations from the standard analytic approach of treating PTB as a binary outcome without considering time-varying exposures together over the course of pregnancy. To address this research gap, we present a Bayesian hierarchical model for conducting a comprehensive examination of gestational air pollution exposure by estimating the joint effects of weekly exposures during different vulnerable periods. Our model also treats PTB as a time-to-event outcome to address the challenge of different exposure lengths among ongoing pregnancies. The proposed model is applied to a dataset of geocoded birth records in the Atlanta metropolitan area between 1999-2005 to examine the risk of PTB associated with gestational exposure to ambient fine particulate matter [Formula: see text]m in aerodynamic diameter (PM[Formula: see text]). We find positive associations between PM[Formula: see text] exposure during early and mid-pregnancy, and evidence that associations are stronger for PTBs occurring around week 30. PMID:25572998

  14. Assessment of critical exposure and outcome windows in time-to-event analysis with application to air pollution and preterm birth study.

    PubMed

    Chang, Howard H; Warren, Joshua L; Darrow, Lnydsey A; Reich, Brian J; Waller, Lance A

    2015-07-01

    In reproductive epidemiology, there is a growing interest to examine associations between air pollution exposure during pregnancy and the risk of preterm birth (PTB). One important research objective is to identify critical periods of exposure and estimate the associated effects at different stages of pregnancy. However, population studies have reported inconsistent findings. This may be due to limitations from the standard analytic approach of treating PTB as a binary outcome without considering time-varying exposures together over the course of pregnancy. To address this research gap, we present a Bayesian hierarchical model for conducting a comprehensive examination of gestational air pollution exposure by estimating the joint effects of weekly exposures during different vulnerable periods. Our model also treats PTB as a time-to-event outcome to address the challenge of different exposure lengths among ongoing pregnancies. The proposed model is applied to a dataset of geocoded birth records in the Atlanta metropolitan area between 1999-2005 to examine the risk of PTB associated with gestational exposure to ambient fine particulate matter [Formula: see text]m in aerodynamic diameter (PM[Formula: see text]). We find positive associations between PM[Formula: see text] exposure during early and mid-pregnancy, and evidence that associations are stronger for PTBs occurring around week 30.

  15. Critical Care

    MedlinePlus

    Critical care helps people with life-threatening injuries and illnesses. It might treat problems such as complications from surgery, ... attention by a team of specially-trained health care providers. Critical care usually takes place in an ...

  16. The effectiveness of critical time intervention for abused women and homeless people leaving Dutch shelters: study protocol of two randomised controlled trials

    PubMed Central

    2013-01-01

    Background One of the main priorities of Dutch organisations providing shelter services is to develop evidence-based interventions in the care for abused women and homeless people. To date, most of these organisations have not used specific intervention models and the interventions which have been implemented rarely have an empirical and theoretical foundation. The present studies aim to examine the effectiveness of critical time intervention (CTI) for abused women and homeless people. Methods In two multi-centre randomised controlled trials we investigate whether CTI, a time-limited (nine month) outreach intervention, is more effective than care-as-usual for abused women and homeless people making the transition from shelter facilities to supported or independent housing. Participants were recruited in 19 women’s shelter facilities and 22 homeless shelter facilities across The Netherlands and randomly allocated to the intervention group (CTI) or the control group (care-as-usual). They were interviewed four times in nine months: once before leaving the shelter, and then at three, six and nine months after leaving the shelter. Quality of life (primary outcome for abused women) and recurrent loss of housing (primary outcome for homeless people) as well as secondary outcomes (e.g. care needs, self-esteem, loneliness, social support, substance use, psychological distress and service use) were assessed during the interviews. In addition, the model integrity of CTI was investigated during the data collection period. Discussion Based on international research CTI is expected to be an appropriate intervention for clients making the transition from institutional to community living. If CTI proves to be effective for abused women and homeless people, shelter services could include this case management model in their professional standards and improve the (quality of) services for clients. Trial registration NTR3463 and NTR3425 PMID:25927562

  17. Archetypal Criticism.

    ERIC Educational Resources Information Center

    Chesebro, James W.; And Others

    1990-01-01

    Argues that archetypal criticism is a useful way of examining universal, historical, and cross-cultural symbols in classrooms. Identifies essential features of an archetype; outlines operational and critical procedures; illustrates archetypal criticism as applied to the cross as a symbol; and provides a synoptic placement for archetypal criticism…

  18. Monoclonal anti-I-A antibody reverses chronic paralysis and demyelination in Theiler's virus-infected mice: critical importance of timing of treatment.

    PubMed

    Friedmann, A; Frankel, G; Lorch, Y; Steinman, L

    1987-03-01

    Susceptibility to demyelination caused by the WW isolate of Theiler's murine encephalomyelitis viruses is linked to class II genes of the major histocompatibility complex. SJL/J (H-2s) mice, expressing only I-As class II gene products of the major histocompatibility complex, are highly susceptible to Theiler's murine encephalomyelitis virus infection with the WW virus isolate, with chronic paralysis and severe inflammation and demyelination in the central nervous system. The effect of in vivo administration of anti-I-As monoclonal antibodies on Theiler's murine encephalomyelitis virus infection was observed. SJL/J mice were treated in various protocols pre- or postinfection. Anti-I-As monoclonal antibody reversed chronic paralysis and reduced inflammation and demyelination when given after the establishment of persistent infection. The effect was long lasting, but clinical signs, inflammation, and demyelination recurred 2 months after treatment ceased. Anti-I-As antibodies had no effect on viral titers within the central nervous system. The timing of the administration of monoclonal antibodies was critical. Administration of anti-I-As before the establishment of the persistent infection resulted in fatal encephalitis.

  19. Monoclonal anti-I-A antibody reverses chronic paralysis and demyelination in Theiler's virus-infected mice: critical importance of timing of treatment.

    PubMed Central

    Friedmann, A; Frankel, G; Lorch, Y; Steinman, L

    1987-01-01

    Susceptibility to demyelination caused by the WW isolate of Theiler's murine encephalomyelitis viruses is linked to class II genes of the major histocompatibility complex. SJL/J (H-2s) mice, expressing only I-As class II gene products of the major histocompatibility complex, are highly susceptible to Theiler's murine encephalomyelitis virus infection with the WW virus isolate, with chronic paralysis and severe inflammation and demyelination in the central nervous system. The effect of in vivo administration of anti-I-As monoclonal antibodies on Theiler's murine encephalomyelitis virus infection was observed. SJL/J mice were treated in various protocols pre- or postinfection. Anti-I-As monoclonal antibody reversed chronic paralysis and reduced inflammation and demyelination when given after the establishment of persistent infection. The effect was long lasting, but clinical signs, inflammation, and demyelination recurred 2 months after treatment ceased. Anti-I-As antibodies had no effect on viral titers within the central nervous system. The timing of the administration of monoclonal antibodies was critical. Administration of anti-I-As before the establishment of the persistent infection resulted in fatal encephalitis. Images PMID:3492612

  20. [Determination of the critical time point for efficacy of L-arginine infusion therapy in a case of MELAS with frequent stroke-like episodes].

    PubMed

    Sudo, Akira; Sano, Hitomi; Kawamura, Nobuaki

    2014-01-01

    MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) is the most representative subtype of mitochondrial diseases. Administration of L-arginine (L-Arg) or a precursor of nitric oxide (NO) has been proposed as a promising medication for MELAS because one of the pathophysiological mechanisms is supposedly a decreased capacity for NO-dependent vasodilation. We experienced a girl with MELAS and frequent stroke-like episodes who was treated with L-Arg infusion. We evaluated the efficacy of L-Arg infusion therapy based on whether her headache and nausea were disappeared and neurological symptoms were improved within 24 hours of L-Arg administration. L-Arg infusions were effective in all four episodes when the treatment was started within 4 hours of the onset of stroke-like episodes. On the other hand, the infusion was effective in only one out of five episodes when the medication was delayed by more than 4 hours after the onset. Furthermore, the early administration of L-Arg resulted in better outcomes regarding new lesions determined by brain MRI. Our data suggest that L-Arg infusion may be most effective when it is started within 4 hours of the onset of neurological symptoms in the acute phase of MELAS. The study of a large number of episodes in many patients will be needed to determine the critical time point of L-Arg administration after the onset of the acute phase of MELAS.

  1. Early gestation as the critical time-window for changes in the prenatal environment to affect the adult human blood methylome

    PubMed Central

    Tobi, Elmar W; Slieker, Roderick C; Stein, Aryeh D; Suchiman, H Eka D; Slagboom, P Eline; van Zwet, Erik W; Heijmans, Bastiaan T; Lumey, LH

    2015-01-01

    Background: The manipulation of pregnancy diets in animals can lead to changes in DNA methylation with phenotypic consequences in the offspring. Human studies have concentrated on the effects of nutrition during early gestation. Lacking in humans is an epigenome-wide association study of DNA methylation in relation to perturbations in nutrition across all gestation periods. Methods: We used the quasi-experimental setting of the Dutch famine of 1944–45 to evaluate the impact of famine exposure during specific 10-week gestation periods, or during any time in gestation, on genome-wide DNA methylation levels at age ∼ 59 years. In addition, we evaluated the impact of exposure during a shorter pre- and post-conception period. DNA methylation was assessed using the Illumina 450k array in whole blood among 422 individuals with prenatal famine exposure and 463 time- or sibling-controls without prenatal famine exposure. Results: Famine exposure during gestation weeks 1–10, but not weeks 11–20, 21–30 or 31-delivery, was associated with an increase in DNA methylation of CpG dinucleotides cg20823026 (FAM150B), cg10354880 (SLC38A2) and cg27370573 (PPAP2C) and a decrease of cg11496778 (OSBPL5/MRGPRG) (P < 5.9 × 10−7, PFDR < 0.031). There was an increase in methylation of TACC1 and ZNF385A after exposure during any time in gestation (P < 2.0 × 10−7, PFDR = 0.034) and a decrease of cg23989336 (TMEM105) after exposure around conception. These changes represent a shift of 0.3–0.6 standard deviations and are linked to genes involved in growth, development and metabolism. Conclusion: Early gestation, and not mid or late gestation, is identified as a critical time-period for adult DNA methylation changes in whole blood after prenatal exposure to famine. PMID:25944819

  2. Critical Thinking vs. Critical Consciousness

    ERIC Educational Resources Information Center

    Doughty, Howard A.

    2006-01-01

    This article explores four kinds of critical thinking. The first is found in Socratic dialogues, which employ critical thinking mainly to reveal logical fallacies in common opinions, thus cleansing superior minds of error and leaving philosophers free to contemplate universal verities. The second is critical interpretation (hermeneutics) which…

  3. Critically Thinking about Critical Thinking

    ERIC Educational Resources Information Center

    Weissberg, Robert

    2013-01-01

    In this article, the author states that "critical thinking" has mesmerized academics across the political spectrum and that even high school students are now being called upon to "think critically." He furthers adds that it is no exaggeration to say that "critical thinking" has quickly evolved into a scholarly…

  4. How Critical Is Critical Thinking?

    ERIC Educational Resources Information Center

    Shaw, Ryan D.

    2014-01-01

    Recent educational discourse is full of references to the value of critical thinking as a 21st-century skill. In music education, critical thinking has been discussed in relation to problem solving and music listening, and some researchers suggest that training in critical thinking can improve students' responses to music. But what exactly is…

  5. Defining critical thoughts.

    PubMed

    Lovatt, Abbie

    2014-05-01

    Nursing education has long struggled to define critical thinking and explain how the process of critical thinking fits into the context of nursing. Despite this long time struggle, nurses and nurse educators continue to strive to foster critical thinking skills in nursing students as intuitively most nurses believe that critical thinking is necessary to function competently in the workplace. This article explores the most recent work of Dr. Stephen Brookfield and ties the concepts which are explored in Brookfield's work to nursing practice. Brookfield identifies that learners understand the meaning of critical thinking the best when the process is first demonstrated. Role modeling is a method educators can use to demonstrate critical thinking and is a strategy which nurses often use in the clinical area to train and mentor new nursing staff. Although it is not a new strategy in nursing education, it is a valuable strategy to engage learners in critical thinking activities. PMID:24418065

  6. Criticality Model

    SciTech Connect

    A. Alsaed

    2004-09-14

    The ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2003) presents the methodology for evaluating potential criticality situations in the monitored geologic repository. As stated in the referenced Topical Report, the detailed methodology for performing the disposal criticality analyses will be documented in model reports. Many of the models developed in support of the Topical Report differ from the definition of models as given in the Office of Civilian Radioactive Waste Management procedure AP-SIII.10Q, ''Models'', in that they are procedural, rather than mathematical. These model reports document the detailed methodology necessary to implement the approach presented in the Disposal Criticality Analysis Methodology Topical Report and provide calculations utilizing the methodology. Thus, the governing procedure for this type of report is AP-3.12Q, ''Design Calculations and Analyses''. The ''Criticality Model'' is of this latter type, providing a process evaluating the criticality potential of in-package and external configurations. The purpose of this analysis is to layout the process for calculating the criticality potential for various in-package and external configurations and to calculate lower-bound tolerance limit (LBTL) values and determine range of applicability (ROA) parameters. The LBTL calculations and the ROA determinations are performed using selected benchmark experiments that are applicable to various waste forms and various in-package and external configurations. The waste forms considered in this calculation are pressurized water reactor (PWR), boiling water reactor (BWR), Fast Flux Test Facility (FFTF), Training Research Isotope General Atomic (TRIGA), Enrico Fermi, Shippingport pressurized water reactor, Shippingport light water breeder reactor (LWBR), N-Reactor, Melt and Dilute, and Fort Saint Vrain Reactor spent nuclear fuel (SNF). The scope of this analysis is to document the criticality computational method. The criticality

  7. Critical Chain Exercises

    ERIC Educational Resources Information Center

    Doyle, John Kevin

    2010-01-01

    Critical Chains project management focuses on holding buffers at the project level vs. task level, and managing buffers as a project resource. A number of studies have shown that Critical Chain project management can significantly improve organizational schedule fidelity (i.e., improve the proportion of projects delivered on time) and reduce…

  8. High-Pressure Oxygenation of Mt-Ybco the way to Reduce the Oxygenation Time, to Prevent Macrocracking, and to Obtain Materials with High Critical Currents.

    NASA Astrophysics Data System (ADS)

    Prikhna, T. A.; Chaud, X.; Gawalek, W.; Joulain, A.; Rabier, J.; Moshchil, V. E.; Savchuk, Ya. M.; Sergienko, N. V.; Dub, S. N.; Melnikov, V. S.; Habisreuther, T.; Litzkendorf, D.; Bierlich, J.

    2008-03-01

    The oxygenation of MT-YBCO under isostatic oxygen pressure (up to 16 MPa) at 900-800 °C allowed reduced process time, lower macrocracking, and reduced microcracks. Additionally higher critical currents, trapped fields and mechanical characteristics can be attained. At 77 K thin-walled MT-YBCO had a jc in the ab plane of 85 kA/cm2 at 0 T and higher than 10 kA/cm2 in fields up to 5 T and the irreversibility field was 9.8 T. In the c-direction jc was 34 kA/cm2 in 0 T and higher than 2.5 kA/cm2 in a 10 T field. At 4.9 N-load the micohardness, Hv, was 8.7±0.3 GPa in the ab-plane and 7.6±0.3 GPa in the c-direction. The fracture toughness, K1C, was 2.5±0.1 MPaṡm0.5 (ab-plane) and 2.8±0.24 MPaṡm0.5 (c-direction). The samples with a higher twin density demonstrated a higher jc, especially in applied magnetic field. The twin density correlates with the sizes and distribution of Y211 grains in Y123. The thin-walled ceramics that demonstrated the highest jc contained about 22 twins in 1 μm and were practically free from dislocations and stacking faults. The maximal trapped field of the block of thin-walled ceramic oxygenated at 900-800 °C and 16 MPa was doubled as compared to that oxygenated at low temperature under ambient pressure.

  9. Critical Muralism

    ERIC Educational Resources Information Center

    Rosette, Arturo

    2009-01-01

    This study focuses on the development and practices of Critical Muralists--community-educator-artist-leader-activists--and situates these specifically in relation to the Mexican mural tradition of los Tres Grandes and in relation to the history of public art more generally. The study examines how Critical Muralists address artistic and…

  10. Critical fluid light scattering

    NASA Technical Reports Server (NTRS)

    Gammon, Robert W.

    1988-01-01

    The objective is to measure the decay rates of critical density fluctuations in a simple fluid (xenon) very near its liquid-vapor critical point using laser light scattering and photon correlation spectroscopy. Such experiments were severely limited on Earth by the presence of gravity which causes large density gradients in the sample when the compressibility diverges approaching the critical point. The goal is to measure fluctuation decay rates at least two decades closer to the critical point than is possible on earth, with a resolution of 3 microK. This will require loading the sample to 0.1 percent of the critical density and taking data as close as 100 microK to the critical temperature. The minimum mission time of 100 hours will allow a complete range of temperature points to be covered, limited by the thermal response of the sample. Other technical problems have to be addressed such as multiple scattering and the effect of wetting layers. The experiment entails measurement of the scattering intensity fluctuation decay rate at two angles for each temperature and simultaneously recording the scattering intensities and sample turbidity (from the transmission). The analyzed intensity and turbidity data gives the correlation length at each temperature and locates the critical temperature. The fluctuation decay rate data from these measurements will provide a severe test of the generalized hydrodynamic theories of transport coefficients in the critical regions. When compared to equivalent data from binary liquid critical mixtures they will test the universality of critical dynamics.

  11. Rapid detection of health-care-associated bloodstream infection in critical care using multipathogen real-time polymerase chain reaction technology: a diagnostic accuracy study and systematic review.

    PubMed Central

    Warhurst, Geoffrey; Dunn, Graham; Chadwick, Paul; Blackwood, Bronagh; McAuley, Daniel; Perkins, Gavin D; McMullan, Ronan; Gates, Simon; Bentley, Andrew; Young, Duncan; Carlson, Gordon L; Dark, Paul

    2015-01-01

    BACKGROUND There is growing interest in the potential utility of real-time polymerase chain reaction (PCR) in diagnosing bloodstream infection by detecting pathogen deoxyribonucleic acid (DNA) in blood samples within a few hours. SeptiFast (Roche Diagnostics GmBH, Mannheim, Germany) is a multipathogen probe-based system targeting ribosomal DNA sequences of bacteria and fungi. It detects and identifies the commonest pathogens causing bloodstream infection. As background to this study, we report a systematic review of Phase III diagnostic accuracy studies of SeptiFast, which reveals uncertainty about its likely clinical utility based on widespread evidence of deficiencies in study design and reporting with a high risk of bias. OBJECTIVE Determine the accuracy of SeptiFast real-time PCR for the detection of health-care-associated bloodstream infection, against standard microbiological culture. DESIGN Prospective multicentre Phase III clinical diagnostic accuracy study using the standards for the reporting of diagnostic accuracy studies criteria. SETTING Critical care departments within NHS hospitals in the north-west of England. PARTICIPANTS Adult patients requiring blood culture (BC) when developing new signs of systemic inflammation. MAIN OUTCOME MEASURES SeptiFast real-time PCR results at species/genus level compared with microbiological culture in association with independent adjudication of infection. Metrics of diagnostic accuracy were derived including sensitivity, specificity, likelihood ratios and predictive values, with their 95% confidence intervals (CIs). Latent class analysis was used to explore the diagnostic performance of culture as a reference standard. RESULTS Of 1006 new patient episodes of systemic inflammation in 853 patients, 922 (92%) met the inclusion criteria and provided sufficient information for analysis. Index test assay failure occurred on 69 (7%) occasions. Adult patients had been exposed to a median of 8 days (interquartile range 4

  12. Critics and Criticism of Education

    ERIC Educational Resources Information Center

    Ornstein, Allan C.

    1977-01-01

    Radical educational critics, such as Edgar Friedenberg, Paul Goodman, A. S. Neill, John Holt, Jonathan Kozol, Herbert Kohl, James Herndon, and Ivan Illich, have few constructive goals, no strategy for broad change, and a disdain for modernization and compromise. Additionally, these critics, says the author, fail to consider social factors related…

  13. Critical power derived from a 3-min all-out test predicts 16.1-km road time-trial performance.

    PubMed

    Black, Matthew I; Durant, Jacob; Jones, Andrew M; Vanhatalo, Anni

    2014-01-01

    It has been shown that the critical power (CP) in cycling estimated using a novel 3-min all-out protocol is reliable and closely matches the CP derived from conventional procedures. The purpose of this study was to assess the predictive validity of the all-out test CP estimate. We hypothesised that the all-out test CP would be significantly correlated with 16.1-km road time-trial (TT) performance and more strongly correlated with performance than the gas exchange threshold (GET), respiratory compensation point (RCP) and VO2 max. Ten club-level male cyclists (mean±SD: age 33.8±8.2 y, body mass 73.8±4.3 kg, VO2 max 60±4 ml·kg(-1)·min(-1)) performed a 10-mile road TT, a ramp incremental test to exhaustion, and two 3-min all-out tests, the first of which served as familiarisation. The 16.1-km TT performance (27.1±1.2 min) was significantly correlated with the CP (309±34 W; r = -0.83, P<0.01) and total work done during the all-out test (70.9±6.5 kJ; r = -0.86, P<0.01), the ramp incremental test peak power (433±30 W; r = -0.75, P<0.05) and the RCP (315±29 W; r = -0.68, P<0.05), but not with GET (151±32 W; r = -0.21) or the VO2 max (4.41±0.25 L·min(-1); r = -0.60). These data provide evidence for the predictive validity and practical performance relevance of the 3-min all-out test. The 3-min all-out test CP may represent a useful addition to the battery of tests employed by applied sport physiologists or coaches to track fitness and predict performance in atheletes.

  14. Effectiveness of a sediment time critical removal action-PCB reduction in fish tissue, surface water, and sediment via wet excavation.

    PubMed

    Santini, Andrew D; King, Todd; Krawczyk, Keith; Kern, John W

    2015-01-01

    Documenting successful remediation of polychlorinated biphenyl (PCB)-contaminated sediments is limited; potentially due to inadequate monitoring methods, complexities associated with the environment, and selected remedial techniques. At some sites, absence of appropriate baseline and postremoval monitoring limits proper evaluation of remedial efficacy. Accurate interpretation of interactions between media, space, time, species, lipid content, and remedial technique requires robust study design and data. This article presents baseline and postremoval data documenting reduced PCB concentrations in fish tissue, surface water, and sediment in response to the US Environmental Protection Agency (USEPA) time-critical removal action (TCRA) that was conducted at the former Bryant Mill Pond (BMP) on Portage Creek in Kalamazoo, Michigan. The BMP is part of an operable unit (OU) within the Allied Paper, Inc./Portage Creek/Kalamazoo River Superfund Site. PCBs discharged to the creek as a byproduct of carbonless copy paper recycling are the primary contaminant of concern. Paper waste residuals commonly appear as gray to light gray clays in river sediments and floodplain soils. The cleanup criterion was 10 mg/kg, with a residual PCB concentration goal of 1 mg/kg. Because the PCB-containing waste is (generally) associated with readily visible light gray clay, excavation of all visibly contaminated current or formerly impounded sediment served as a surrogate for the cleanup criteria and goal. Sediment was wet excavated and backfilled after diversion of the creek. After confirmation that PCB concentrations met cleanup criteria, the stream was diverted to the excavated side, and excavation and backfilling were completed. Overall, 146000 cubic yards of material including PCB-contaminated sediments were removed from the BMP. The long-term monitoring (LTM) program implemented by the Michigan Department of Environmental Quality (MDEQ), and historic data from a variety of sources

  15. Effectiveness of a sediment time critical removal action-PCB reduction in fish tissue, surface water, and sediment via wet excavation.

    PubMed

    Santini, Andrew D; King, Todd; Krawczyk, Keith; Kern, John W

    2015-01-01

    Documenting successful remediation of polychlorinated biphenyl (PCB)-contaminated sediments is limited; potentially due to inadequate monitoring methods, complexities associated with the environment, and selected remedial techniques. At some sites, absence of appropriate baseline and postremoval monitoring limits proper evaluation of remedial efficacy. Accurate interpretation of interactions between media, space, time, species, lipid content, and remedial technique requires robust study design and data. This article presents baseline and postremoval data documenting reduced PCB concentrations in fish tissue, surface water, and sediment in response to the US Environmental Protection Agency (USEPA) time-critical removal action (TCRA) that was conducted at the former Bryant Mill Pond (BMP) on Portage Creek in Kalamazoo, Michigan. The BMP is part of an operable unit (OU) within the Allied Paper, Inc./Portage Creek/Kalamazoo River Superfund Site. PCBs discharged to the creek as a byproduct of carbonless copy paper recycling are the primary contaminant of concern. Paper waste residuals commonly appear as gray to light gray clays in river sediments and floodplain soils. The cleanup criterion was 10 mg/kg, with a residual PCB concentration goal of 1 mg/kg. Because the PCB-containing waste is (generally) associated with readily visible light gray clay, excavation of all visibly contaminated current or formerly impounded sediment served as a surrogate for the cleanup criteria and goal. Sediment was wet excavated and backfilled after diversion of the creek. After confirmation that PCB concentrations met cleanup criteria, the stream was diverted to the excavated side, and excavation and backfilling were completed. Overall, 146000 cubic yards of material including PCB-contaminated sediments were removed from the BMP. The long-term monitoring (LTM) program implemented by the Michigan Department of Environmental Quality (MDEQ), and historic data from a variety of sources

  16. In-Network Processing for Mission-Critical Wireless Networked Sensing and Control: A Real-Time, Efficiency, and Resiliency Perspective

    ERIC Educational Resources Information Center

    Xiang, Qiao

    2014-01-01

    As wireless cyber-physical systems (WCPS) are increasingly being deployed in mission-critical applications, it becomes imperative that we consider application QoS requirements in in-network processing (INP). In this dissertation, we explore the potentials of two INP methods, packet packing and network coding, on improving network performance while…

  17. Rethinking Creative Teaching and Teaching as Research: Mapping the Critical Phases that Mark Times of Change and Choosing as Learners and Teachers of Music

    ERIC Educational Resources Information Center

    Burnard, Pamela

    2012-01-01

    This article describes the use of a visual-based construct elicitation tool developed from the use of critical incident charting for the purpose of reflecting on our creative learning journeys either at significant points as music learners in childhood, in adult life, or as preservice or experienced teachers. In this article, I introduce diverse…

  18. Quantum criticality of a spin-1 XY model with easy-plane single-ion anisotropy via a two-time Green function approach avoiding the Anderson-Callen decoupling

    NASA Astrophysics Data System (ADS)

    Mercaldo, M. T.; Rabuffo, I.; De Cesare, L.; Caramico D'Auria, A.

    2016-04-01

    In this work we study the quantum phase transition, the phase diagram and the quantum criticality induced by the easy-plane single-ion anisotropy in a d-dimensional quantum spin-1 XY model in absence of an external longitudinal magnetic field. We employ the two-time Green function method by avoiding the Anderson-Callen decoupling of spin operators at the same sites which is of doubtful accuracy. Following the original Devlin procedure we treat exactly the higher order single-site anisotropy Green functions and use Tyablikov-like decouplings for the exchange higher order ones. The related self-consistent equations appear suitable for an analysis of the thermodynamic properties at and around second order phase transition points. Remarkably, the equivalence between the microscopic spin model and the continuous O(2) -vector model with transverse-Ising model (TIM)-like dynamics, characterized by a dynamic critical exponent z=1, emerges at low temperatures close to the quantum critical point with the single-ion anisotropy parameter D as the non-thermal control parameter. The zero-temperature critic anisotropy parameter Dc is obtained for dimensionalities d > 1 as a function of the microscopic exchange coupling parameter and the related numerical data for different lattices are found to be in reasonable agreement with those obtained by means of alternative analytical and numerical methods. For d > 2, and in particular for d=3, we determine the finite-temperature critical line ending in the quantum critical point and the related TIM-like shift exponent, consistently with recent renormalization group predictions. The main crossover lines between different asymptotic regimes around the quantum critical point are also estimated providing a global phase diagram and a quantum criticality very similar to the conventional ones.

  19. Critical chemotactic collapse

    NASA Astrophysics Data System (ADS)

    Lushnikov, Pavel M.

    2010-04-01

    A Keller-Segel model describes macroscopic dynamics of bacterial colonies and biological cells as well as dynamics of a gas of self-gravitating Brownian particles. Bacteria secret chemical which attracts other bacteria so that they move towards chemical gradient creating nonlocal attraction between bacteria. If bacterial (or Brownian particle) density exceeds a critical value then the density collapses (blows up) in a finite time which corresponds to bacterial aggregation or gravitational collapse. Collapse in the Keller-Segel model has striking qualitative similarities with a nonlinear Schrödinger equation including critical collapse in two dimensions and supercritical collapse in three dimensions. A self-similar solution near blow up point is studied in the critical two-dimensional case and it has a form of a rescaled steady state solution which contains a critical number of bacteria. Time dependence of scaling of that solution has square root scaling law with logarithmic modification.

  20. Greening critical care

    PubMed Central

    2011-01-01

    Climate change and environmental stewardship are phrases that have been defining the past few decades and promoting change in our societies. The sensitivities of intensive care as a specialty make the process of greening an intensive care unit a challenge, but not one that is insurmountable. This paper discusses opportunities for critical care to reduce its environmental impact and provide a framework change. The article includes suggestions of what can be done as an individual, as a unit and as a hospital. Generally, practices in critical care are accepted without questioning the environmental consequences. We believe it is time for change, and critical care should give environmental stewardship a higher priority. PMID:21635700

  1. Mission Critical Networking

    SciTech Connect

    Eltoweissy, Mohamed Y.; Du, David H.C.; Gerla, Mario; Giordano, Silvia; Gouda, Mohamed; Schulzrinne, Henning; Youssef, Moustafa

    2010-06-01

    Mission-Critical Networking (MCN) refers to networking for application domains where life or livelihood may be at risk. Typical application domains for MCN include critical infrastructure protection and operation, emergency and crisis intervention, healthcare services, and military operations. Such networking is essential for safety, security and economic vitality in our complex world characterized by uncertainty, heterogeneity, emergent behaviors, and the need for reliable and timely response. MCN comprise networking technology, infrastructures and services that may alleviate the risk and directly enable and enhance connectivity for mission-critical information exchange among diverse, widely dispersed, mobile users.

  2. Staying Critical

    ERIC Educational Resources Information Center

    Carr, Wilfred; Kemmis, Stephen

    2005-01-01

    In this article, the two authors of "Becoming Critical: education, knowledge and action research" look back at the book's history since its publication 20 years ago. We describe how the book was originally written, and the diverse responses and reactions that it has produced. We identify some of the book's inadequacies and limitations, and…

  3. [Scoring system for early detection of critical illness can fail].

    PubMed

    Kamstrup Christiansen, Lærke; Andreasen, Jo Bønding; Frederiksen, Christian Alcaraz; Juhl-Olsen, Peter; Sloth, Erik

    2013-02-18

    A 57-year old male underwent elective aortic valve replacement. The immediate post-operative course was uneventful and the patient was discharged with the lowest possible score on a newly implemented scale for early detection of critical illness. The following day he was readmitted with dyspnoea. The critical illness score was still low despite ultrasonic demonstration of a large pericardial effusion requiring drainage. We are concerned that the widely adopted critical illness scale is not sufficiently sensitive for cardiac surgery patients and advocate the use of point-of-care ultrasound.

  4. Adipose tissue alterations in critical illness: a paradox as to patient outcomes.

    PubMed

    Wade, Charles E

    2013-09-20

    Adipocyte morphological changes in critically ill patients have been reported, potentially providing beneficial effects. Marques and colleagues reported that these morphological adipocyte changes, as well as accumulation of M2 phenotype macrophages, occur irrespective of nutritional status in the critically ill. The present study provides insight into the alterations that occur, although further studies are needed to fully understand the role that adipose tissue plays in the critically injured.

  5. Critical Information at Critical Moments

    ERIC Educational Resources Information Center

    Fierman, Ben; Thrower, Raymond H., Jr.

    2011-01-01

    On a daily basis, administrators are reminded of the potential, perhaps the likelihood, of violence or natural crises on their campuses. Comprehensive studies have been conducted and point to recommendations and best practices for planning, preparing, responding to, and recovering from critical incidents. The International Association of Campus…

  6. Optimal Egg Size in Marine Invertebrates: Theory and Phylogenetic Analysis of the Critical Relationship between Egg Size and Development Time in Echinoids.

    PubMed

    Levitan

    2000-08-01

    Life-history models for marine invertebrate larvae generally predict a dichotomy in egg size in different species: eggs should be either minimal in size or large enough to support development fully without larval feeding. This prediction is contradicted, however, by the empirical observation of wide, continuous variation in egg size between these extremes. The prediction of dichotomy rests on the assumption of a negative linear relationship between egg size and development time. Here, I present a simple model in which development time is inversely proportional to egg size. Incorporating this relationship into an optimality model produces predictions of intermediate rather than extreme egg size. Modeled variations in mortality, food availability, fertilization rates, and temperature all produce continuous shifts in the value of the intermediate optimal size, in direct contrast to those produced by previous models, which predict shifts between two extreme optima. Empirical data on echinoid egg size and development time strongly support the model's assumption of an inverse proportional relationship between egg size and development time. A composite phylogeny is constructed of the 37 species for which egg size, development time, water temperature, and phylogenetic relatedness are known. Independent contrasts are made of the evolutionary changes in egg size and development time. This analysis indicates that evolutionary shifts in development time are correlated with the inversely proportional shifts in egg size assumed in the model. The assumption of a negative linear relationship used in previous models is rejected. This model provides a potential explanation for intraspecific variation in egg size along environmental gradients, sympatric differences in egg size among species, and biogeographic trends in egg size and development mode across taxa.

  7. District health planning at a time of transition: a critical review and lessons learnt from the implementation of regional planning in Uganda.

    PubMed

    Curtale, Filippo; Musila, Timothy; Opigo, Jimmy; Nantamu, Dyogo; Ezati, Isaac Alidria

    2016-05-01

    A quarter of a century after the Harare Declaration on Strengthening District Health Systems Based on Primary Health Care (1987) was conceived, district health teams (DHTs) are facing a markedly changed situation. Rapid population growth, urbanization, a rapidly developing private sector, and the increasing role of vertical programs and global initiatives have marginalized the planning process and weakened the entire district health system (DHS). The Ugandan Ministry of Health (MoH) responded to these challenges by beginning a review of district planning: a key action point of the Harare Declaration. The first step was a critical review of relevant literature, then central and district health staff were engaged with to provide their input in developing the new strategy. Through a field experiment started in 2012-13, and still underway, the MoH is developing an innovative regional approach to health planning, which aims to encompass the complexity of the new context of health care provision and coordinate all new actors (private health providers, projects and local government staff from other sectors) operating in the health sector. A strategic revision of the planning process represents an opportunity to develop an appropriate 'Theory of Change', intended as a broader approach of thinking about the entire DHS and the relative role and functions of the DHT. Leadership and stewardship capacities of MoH staff, at central and peripheral level, must be strengthened and supported to achieve the expected changes and results. PMID:27178674

  8. District health planning at a time of transition: a critical review and lessons learnt from the implementation of regional planning in Uganda.

    PubMed

    Curtale, Filippo; Musila, Timothy; Opigo, Jimmy; Nantamu, Dyogo; Ezati, Isaac Alidria

    2016-05-01

    A quarter of a century after the Harare Declaration on Strengthening District Health Systems Based on Primary Health Care (1987) was conceived, district health teams (DHTs) are facing a markedly changed situation. Rapid population growth, urbanization, a rapidly developing private sector, and the increasing role of vertical programs and global initiatives have marginalized the planning process and weakened the entire district health system (DHS). The Ugandan Ministry of Health (MoH) responded to these challenges by beginning a review of district planning: a key action point of the Harare Declaration. The first step was a critical review of relevant literature, then central and district health staff were engaged with to provide their input in developing the new strategy. Through a field experiment started in 2012-13, and still underway, the MoH is developing an innovative regional approach to health planning, which aims to encompass the complexity of the new context of health care provision and coordinate all new actors (private health providers, projects and local government staff from other sectors) operating in the health sector. A strategic revision of the planning process represents an opportunity to develop an appropriate 'Theory of Change', intended as a broader approach of thinking about the entire DHS and the relative role and functions of the DHT. Leadership and stewardship capacities of MoH staff, at central and peripheral level, must be strengthened and supported to achieve the expected changes and results.

  9. A Critical Analysis of the Role of Wait Time in Classroom Interactions and the Effects on Student and Teacher Interactional Behaviours

    ERIC Educational Resources Information Center

    Ingram, Jenni; Elliott, Victoria

    2016-01-01

    Extending the pauses between teachers' and students' turns (wait time) has been recommended as a way of improving classroom learning. Drawing on the Conversation Analysis literature on classroom interactions alongside extracts of classroom interactions, the relationship between these pauses and the interactional behaviour of teachers and students…

  10. Reviews/Essays: School Start Times and the Sleep-Wake Cycle of Adolescents--A Review and Critical Evaluation of Available Evidence

    ERIC Educational Resources Information Center

    Kirby, Matthew; Maggi, Stefania; D'Angiulli, Amedeo

    2011-01-01

    The authors have integrated the major findings on the sleep-wake cycle and its performance correlates in adolescents. Basic research shows that lack of synchronicity between early school start times and the circadian rhythm of adolescents (and the sleep debt accumulated as a result) involves several cognitive correlates that may harm the academic…

  11. Applying critical thinking to nursing.

    PubMed

    Price, Bob

    2015-08-19

    Critical thinking and writing are skills that are not easy to acquire. The term 'critical' is used differently in social and clinical contexts. Nursing students need time to master the inquisitive and ruminative aspects of critical thinking that are required in academic environments. This article outlines what is meant by critical thinking in academic settings, in relation to both theory and reflective practice. It explains how the focus of a question affects the sort of critical thinking required and offers two taxonomies of learning, to which students can refer when analysing essay requirements. The article concludes with examples of analytical writing in reference to theory and reflective practice.

  12. Unmanned Aerial Vehicle (UAV) Dynamic-Tracking Directional Wireless Antennas for Low Powered Applications that Require Reliable Extended Range Operations in Time Critical Scenarios

    SciTech Connect

    Scott G. Bauer; Matthew O. Anderson; James R. Hanneman

    2005-10-01

    The proven value of DOD Unmanned Aerial Vehicles (UAVs) will ultimately transition to National and Homeland Security missions that require real-time aerial surveillance, situation awareness, force protection, and sensor placement. Public services first responders who routinely risk personal safety to assess and report a situation for emergency actions will likely be the first to benefit from these new unmanned technologies. ‘Packable’ or ‘Portable’ small class UAVs will be particularly useful to the first responder. They require the least amount of training, no fixed infrastructure, and are capable of being launched and recovered from the point of emergency. All UAVs require wireless communication technologies for real- time applications. Typically on a small UAV, a low bandwidth telemetry link is required for command and control (C2), and systems health monitoring. If the UAV is equipped with a real-time Electro-Optical or Infrared (EO/Ir) video camera payload, a dedicated high bandwidth analog/digital link is usually required for reliable high-resolution imagery. In most cases, both the wireless telemetry and real-time video links will be integrated into the UAV with unity gain omni-directional antennas. With limited on-board power and payload capacity, a small UAV will be limited with the amount of radio-frequency (RF) energy it transmits to the users. Therefore, ‘packable’ and ‘portable’ UAVs will have limited useful operational ranges for first responders. This paper will discuss the limitations of small UAV wireless communications. The discussion will present an approach of utilizing a dynamic ground based real-time tracking high gain directional antenna to provide extend range stand-off operation, potential RF channel reuse, and assured telemetry and data communications from low-powered UAV deployed wireless assets.

  13. Science education in Africa; A critical time for critical thinking.

    NASA Astrophysics Data System (ADS)

    Murabona, S.; Daka, O.; Chileshi, M.; Darrow, J.; Tung, A.; Wanless, E.; Hand, K.

    2005-12-01

    The change toward industrialization and a technologically advanced society is occurring at an ever increasing rate in developing regions of the world. Such change brings with it both the benefits of access to medicine, water, and food, and the negative effects of pollution, the destruction of natural resources, and the loss of both cultural and biological diversity. In many developing regions the human population is uneducated and incapable of playing an active role in the changes occurring around them. Here we discuss the work of our small non-profit, Cosmos Education, and our efforts to improve basic science education in sub-Saharan Africa. The mission of Cosmos Education is to foster global sustainable development through improved science and technology education in developing regions of the world. Our guiding vision is quite simple: Youth are the future. Education is the key. Cosmos Education aims to make a sustained and effective difference by working from the ground up - reaching individual students and teachers and making a difference in the classroom. We focus on science and technology education and the role of science and technology in health, the environment, and sustainable development. Our model is grassroots development from within; we want the youth in developing regions of the world to decide how their nations develop. In order to be able to do this, the youth must have the knowledge and skills needed to understand the rapidly changing world around them. They must be inspired, empowered, and engaged in their education. By working directly in classrooms, making learning fun with hands-on experiments, and providing the students with talented role-models from their own geographic region, we hope to excite students about their potential drive development from within and to catalyze development that will have a positive effect on the biosphere.

  14. Nuclear criticality information system

    SciTech Connect

    Koponen, B.L.; Hampel, V.E.

    1981-11-30

    The nuclear criticality safety program at LLNL began in the 1950's with a critical measurements program which produced benchmark data until the late 1960's. This same time period saw the rapid development of computer technology useful for both computer modeling of fissile systems and for computer-aided management and display of the computational benchmark data. Database management grew in importance as the amount of information increased and as experimental programs were terminated. Within the criticality safety program at LLNL we began at that time to develop a computer library of benchmark data for validation of computer codes and cross sections. As part of this effort, we prepared a computer-based bibliography of criticality measurements on relatively simple systems. However, it is only now that some of these computer-based resources can be made available to the nuclear criticality safety community at large. This technology transfer is being accomplished by the DOE Technology Information System (TIS), a dedicated, advanced information system. The NCIS database is described.

  15. Real-Time 3D Fluoroscopy-Guided Large Core Needle Biopsy of Renal Masses: A Critical Early Evaluation According to the IDEAL Recommendations

    SciTech Connect

    Kroeze, Stephanie G. C.; Huisman, Merel; Verkooijen, Helena M.; Diest, Paul J. van; Ruud Bosch, J. L. H.; Bosch, Maurice A. A. J. van den

    2012-06-15

    Introduction: Three-dimensional (3D) real-time fluoroscopy cone beam CT is a promising new technique for image-guided biopsy of solid tumors. We evaluated the technical feasibility, diagnostic accuracy, and complications of this technique for guidance of large-core needle biopsy in patients with suspicious renal masses. Methods: Thirteen patients with 13 suspicious renal masses underwent large-core needle biopsy under 3D real-time fluoroscopy cone beam CT guidance. Imaging acquisition and subsequent 3D reconstruction was done by a mobile flat-panel detector (FD) C-arm system to plan the needle path. Large-core needle biopsies were taken by the interventional radiologist. Technical success, accuracy, and safety were evaluated according to the Innovation, Development, Exploration, Assessment, Long-term study (IDEAL) recommendations. Results: Median tumor size was 2.6 (range, 1.0-14.0) cm. In ten (77%) patients, the histological diagnosis corresponded to the imaging findings: five were malignancies, five benign lesions. Technical feasibility was 77% (10/13); in three patients biopsy results were inconclusive. The lesion size of these three patients was <2.5 cm. One patient developed a minor complication. Median follow-up was 16.0 (range, 6.4-19.8) months. Conclusions: 3D real-time fluoroscopy cone beam CT-guided biopsy of renal masses is feasible and safe. However, these first results suggest that diagnostic accuracy may be limited in patients with renal masses <2.5 cm.

  16. Lung ultrasound in the critically ill

    PubMed Central

    2014-01-01

    Lung ultrasound is a basic application of critical ultrasound, defined as a loop associating urgent diagnoses with immediate therapeutic decisions. It requires the mastery of ten signs: the bat sign (pleural line), lung sliding (yielding seashore sign), the A-line (horizontal artifact), the quad sign, and sinusoid sign indicating pleural effusion, the fractal, and tissue-like sign indicating lung consolidation, the B-line, and lung rockets indicating interstitial syndrome, abolished lung sliding with the stratosphere sign suggesting pneumothorax, and the lung point indicating pneumothorax. Two more signs, the lung pulse and the dynamic air bronchogram, are used to distinguish atelectasis from pneumonia. All of these disorders were assessed using CT as the “gold standard” with sensitivity and specificity ranging from 90% to 100%, allowing ultrasound to be considered as a reasonable bedside “gold standard” in the critically ill. The BLUE-protocol is a fast protocol (<3 minutes), which allows diagnosis of acute respiratory failure. It includes a venous analysis done in appropriate cases. Pulmonary edema, pulmonary embolism, pneumonia, chronic obstructive pulmonary disease, asthma, and pneumothorax yield specific profiles. Pulmonary edema, e.g., yields anterior lung rockets associated with lung sliding, making the “B-profile.” The FALLS-protocol adapts the BLUE-protocol to acute circulatory failure. It makes sequential search for obstructive, cardiogenic, hypovolemic, and distributive shock using simple real-time echocardiography (right ventricle dilatation, pericardial effusion), then lung ultrasound for assessing a direct parameter of clinical volemia: the apparition of B-lines, schematically, is considered as the endpoint for fluid therapy. Other aims of lung ultrasound are decreasing medical irradiation: the LUCIFLR program (most CTs in ARDS or trauma can be postponed), a use in traumatology, intensive care unit, neonates (the signs are the same than

  17. Lung ultrasound in the critically ill.

    PubMed

    Lichtenstein, Daniel A

    2014-01-01

    Lung ultrasound is a basic application of critical ultrasound, defined as a loop associating urgent diagnoses with immediate therapeutic decisions. It requires the mastery of ten signs: the bat sign (pleural line), lung sliding (yielding seashore sign), the A-line (horizontal artifact), the quad sign, and sinusoid sign indicating pleural effusion, the fractal, and tissue-like sign indicating lung consolidation, the B-line, and lung rockets indicating interstitial syndrome, abolished lung sliding with the stratosphere sign suggesting pneumothorax, and the lung point indicating pneumothorax. Two more signs, the lung pulse and the dynamic air bronchogram, are used to distinguish atelectasis from pneumonia. All of these disorders were assessed using CT as the "gold standard" with sensitivity and specificity ranging from 90% to 100%, allowing ultrasound to be considered as a reasonable bedside "gold standard" in the critically ill. The BLUE-protocol is a fast protocol (<3 minutes), which allows diagnosis of acute respiratory failure. It includes a venous analysis done in appropriate cases. Pulmonary edema, pulmonary embolism, pneumonia, chronic obstructive pulmonary disease, asthma, and pneumothorax yield specific profiles. Pulmonary edema, e.g., yields anterior lung rockets associated with lung sliding, making the "B-profile." The FALLS-protocol adapts the BLUE-protocol to acute circulatory failure. It makes sequential search for obstructive, cardiogenic, hypovolemic, and distributive shock using simple real-time echocardiography (right ventricle dilatation, pericardial effusion), then lung ultrasound for assessing a direct parameter of clinical volemia: the apparition of B-lines, schematically, is considered as the endpoint for fluid therapy. Other aims of lung ultrasound are decreasing medical irradiation: the LUCIFLR program (most CTs in ARDS or trauma can be postponed), a use in traumatology, intensive care unit, neonates (the signs are the same than in adults

  18. One-year mortality, quality of life and predicted life-time cost-utility in critically ill patients with acute respiratory failure

    PubMed Central

    2010-01-01

    Introduction High daily intensive care unit (ICU) costs are associated with the use of mechanical ventilation (MV) to treat acute respiratory failure (ARF), and assessment of quality of life (QOL) after critical illness and cost-effectiveness analyses are warranted. Methods Nationwide, prospective multicentre observational study in 25 Finnish ICUs. During an eight-week study period 958 consecutive adult ICU patients were treated with ventilatory support over 6 hours. Of those 958, 619 (64.6%) survived one year, of whom 288 (46.5%) answered the quality of life questionnaire (EQ-5D). We calculated EQ-5D index and predicted lifetime quality-adjusted life years (QALYs) gained using the age- and sex-matched life expectancy for survivors after one year. For expired patients the exact lifetime was used. We divided all hospital costs for all ARF patients by the number of hospital survivors, and by all predicted lifetime QALYs. We also adjusted for those who died before one year and for those with missing QOL to be able to estimate the total QALYs. Results One-year mortality was 35% (95% CI 32 to 38%). For the 288 respondents median [IQR] EQ-5D index after one year was lower than that of the age- and sex-matched general population 0.70 [0.45 to 0.89] vs. 0.84 [0.81 to 0.88]. For these 288, the mean (SD) predicted lifetime QALYs was 15.4 (13.3). After adjustment for missing QOL the mean predicted lifetime (SD) QALYs was 11.3 (13.0) for all the 958 ARF patients. The mean estimated costs were 20.739 € per hospital survivor, and mean predicted lifetime cost-utility for all ARF patients was 1391 € per QALY. Conclusions Despite lower health-related QOL compared to reference values, our result suggests that cost per hospital survivor and lifetime cost-utility remain reasonable regardless of age, disease severity, and type or duration of ventilation support in patients with ARF. PMID:20384998

  19. Characterization of attenuated food motivation in high-fat diet-induced obesity: Critical roles for time on diet and reinforcer familiarity.

    PubMed

    Tracy, Andrea L; Wee, Colin J M; Hazeltine, Grace E; Carter, Rebecca A

    2015-03-15

    Prior work using animal models to study the effects of obesogenic diets on food motivation have generated inconsistent results, with some reporting increases and others reporting decreases in responding on food-reinforced tasks. Here, we identified two specific variables that may account for these discrepant outcomes - the length of time on the obesigenic diet and the familiarity of the food reinforcer - and examined the independent roles of these factors. Time on diet was found to be inversely related to food motivation, as rats consuming a 40% high-fat diet (HFD) for only 3weeks did not differ from chow-fed rats when responding for a sucrose reinforcer on a progressive ratio (PR) schedule, but responding was suppressed after 6weeks of ad lib HFD consumption. Explicitly manipulating experience with the sucrose reinforcer by pre-exposing half the rats prior to 10weeks of HFD consumption attenuated the motivational deficit seen in the absence of this familiarity, resulting in obese rats performing at the same level as lean rats. Finally, after 8weeks on a HFD, rats did not express a conditioned place preference for sucrose, indicating a decrement in reward value independent of motivation. These findings are consistent with prior literature showing an increase in food motivation for rats with a shorter time consuming the obesigenic diet, and for those with more prior experience with the reinforcer. This account also helps reconcile these findings with increased food motivation in obese humans due to extensive experience with palatable food and suggests that researchers engaging in non-human animal studies of obesity would better model the conditions under which human obesity develops by using a varied, cafeteria-style diet to increase the breadth of food experiences. PMID:25582517

  20. Characterization of attenuated food motivation in high-fat diet-induced obesity: Critical roles for time on diet and reinforcer familiarity.

    PubMed

    Tracy, Andrea L; Wee, Colin J M; Hazeltine, Grace E; Carter, Rebecca A

    2015-03-15

    Prior work using animal models to study the effects of obesogenic diets on food motivation have generated inconsistent results, with some reporting increases and others reporting decreases in responding on food-reinforced tasks. Here, we identified two specific variables that may account for these discrepant outcomes - the length of time on the obesigenic diet and the familiarity of the food reinforcer - and examined the independent roles of these factors. Time on diet was found to be inversely related to food motivation, as rats consuming a 40% high-fat diet (HFD) for only 3weeks did not differ from chow-fed rats when responding for a sucrose reinforcer on a progressive ratio (PR) schedule, but responding was suppressed after 6weeks of ad lib HFD consumption. Explicitly manipulating experience with the sucrose reinforcer by pre-exposing half the rats prior to 10weeks of HFD consumption attenuated the motivational deficit seen in the absence of this familiarity, resulting in obese rats performing at the same level as lean rats. Finally, after 8weeks on a HFD, rats did not express a conditioned place preference for sucrose, indicating a decrement in reward value independent of motivation. These findings are consistent with prior literature showing an increase in food motivation for rats with a shorter time consuming the obesigenic diet, and for those with more prior experience with the reinforcer. This account also helps reconcile these findings with increased food motivation in obese humans due to extensive experience with palatable food and suggests that researchers engaging in non-human animal studies of obesity would better model the conditions under which human obesity develops by using a varied, cafeteria-style diet to increase the breadth of food experiences.

  1. Survival of time-evolved quantum correlations depending on whether quenching is across a critical point in an X Y spin chain

    NASA Astrophysics Data System (ADS)

    Mishra, Utkarsh; Rakshit, Debraj; Prabhu, R.

    2016-04-01

    The time dynamics of quantum correlations in the quantum transverse anisotropic X Y spin chain of infinite length is studied at zero and finite temperatures. The evolution occurs due to the instantaneous quenching of the coupling constant between the nearest-neighbor spins of the model, which is performed either within the same phase or across the quantum phase-transition point connecting the order-disorder phases of the model. We characterize the time-evolved quantum correlations, viz., entanglement and quantum discord, which exhibit varying behavior depending on the initial state and the quenching scheme. We show that the system is endowed with enhanced nearest-neighbor bipartite quantum correlations compared to that of the initial state, when quenched from the ordered to the deep disordered phase. However, nearest-neighbor quantum correlations are almost washed out when the system is quenched from the disordered to the ordered phase with the initial state being at the zero temperature. We also identify the condition for the occurrence of enhanced bipartite correlations when the system is quenched within the same phase. Moreover, we investigate the bipartite quantum correlations when the initial state is a thermal equilibrium state with finite temperature, which reveals the effects of thermal fluctuation on the phenomena observed at zero temperature. Finally, an analogous analysis is carried out for zero-temperature next-nearest-neighbor quantum correlations.

  2. CISN Display Progress to Date - Reliable Delivery of Real-Time Earthquake Information, and ShakeMap to Critical End Users

    NASA Astrophysics Data System (ADS)

    Rico, H.; Hauksson, E.; Thomas, E.; Friberg, P.; Frechette, K.; Given, D.

    2003-12-01

    The California Integrated Seismic Network (CISN) has collaborated to develop a next-generation earthquake notification system that is nearing its first operations-ready release. The CISN Display actively alerts users of seismic data, and vital earthquake hazards information following a significant event. It will primarily replace the Caltech/USGS Broadcast of Earthquakes (CUBE) and Rapid Earthquake Data Integration (REDI) Display as the principal means of delivering geographical seismic data to emergency operations centers, utility companies and media outlets. A subsequent goal is to provide automated access to the many Web products produced by regional seismic networks after an earthquake. Another aim is to create a highly configurable client, allowing user organizations to overlay infrastructure data critical to their roles as first-responders, or lifeline operators. And the final goal is to integrate these requirements, into a package offering several layers of reliability to ensure delivery of services. Central to the CISN Display's role as a gateway to Web-based earthquake products is its comprehensive XML-messaging schema. The message model uses many of the same attributes in the CUBE format, but extends the old standard by provisioning additional elements for products currently available, and others yet to be considered. The client consumes these XML-messages, sorts them through a resident Quake Data Merge filter, and posts updates that also include hyperlinks associated to specific event IDs on the display map. Earthquake products available for delivery to the CISN Display are ShakeMap, focal mechanisms, waveform data, felt reports, aftershock forecasts and earthquake commentaries. By design the XML-message schema can evolve as products and information needs change, without breaking existing applications that rely on it. The latest version of the CISN Display can also automatically download ShakeMaps and display shaking intensity within the GIS system. This

  3. Prediction of critical illness in elderly outpatients using elder risk assessment: a population-based study

    PubMed Central

    Biehl, Michelle; Takahashi, Paul Y; Cha, Stephen S; Chaudhry, Rajeev; Gajic, Ognjen; Thorsteinsdottir, Bjorg

    2016-01-01

    Rationale Identifying patients at high risk of critical illness is necessary for the development and testing of strategies to prevent critical illness. The aim of this study was to determine the relationship between high elder risk assessment (ERA) score and critical illness requiring intensive care and to see if the ERA can be used as a prediction tool to identify elderly patients at the primary care visit who are at high risk of critical illness. Methods A population-based historical cohort study was conducted in elderly patients (age >65 years) identified at the time of primary care visit in Rochester, MN, USA. Predictors including age, previous hospital days, and comorbid health conditions were identified from routine administrative data available in the electronic medical record. The main outcome was critical illness, defined as sepsis, need for mechanical ventilation, or death within 2 years of initial visit. Patients with an ERA score of 16 were considered to be at high risk. The discrimination of the ERA score was assessed using area under the receiver operating characteristic curve. Results Of the 13,457 eligible patients, 9,872 gave consent for medical record review and had full information on intensive care unit utilization. The mean age was 75.8 years (standard deviation ±7.6 years), and 58% were female, 94% were Caucasian, 62% were married, and 13% were living in nursing homes. In the overall group, 417 patients (4.2%) suffered from critical illness. In the 1,134 patients with ERA >16, 154 (14%) suffered from critical illness. An ERA score ≥16 predicted critical illness (odds ratio 6.35; 95% confidence interval 3.51–11.48). The area under the receiver operating characteristic curve was 0.75, which indicated good discrimination. Conclusion A simple model based on easily obtainable administrative data predicted critical illness in the next 2 years in elderly outpatients with up to 14% of the highest risk population suffering from critical illness

  4. Critical Assessment of Time-Dependent Density Functional Theory for Excited States of Open-Shell Systems: II. Doublet-Quartet Transitions.

    PubMed

    Li, Zhendong; Liu, Wenjian

    2016-06-14

    Compared with closed-shell systems, open-shell systems place three additional challenges to time-dependent density functional theory (TD-DFT) for electronically excited states: (a) the spin-contamination problem is a serious issue; (b) the exchange-correlation (XC) kernel may be numerically instable; and (c) the single-determinant description of open-shell ground states readily becomes energetically instable. Confined to flip-up single excitations, the spin-contamination problem can largely be avoided by using the spin-flip TD-DFT (SF-TD-DFT) formalism, provided that a noncollinear XC kernel is employed. As for the numerical instabilities associated with such a kernel, only an ad hoc scheme has been proposed so far, viz., the ALDA0 kernel, which amounts to setting the divergent components (arising from density gradients and kinetic energy density) simply to zero. The ground-state instability problem can effectively be avoided by introducing the Tamm-Dancoff approximation (TDA) to TD-DFT. Therefore, on a general basis, the SF-TDA/ALDA0 Ansatz is so far the only promising means within the TD-DFT framework for flip-up single excitations of open-shell systems. To assess systematically the performance of SF-TDA/ALDA0, in total 61 low-lying quartet excited states of the benchmark set of 11 small radicals [J. Chem. Theory Comput. 2016, 12, 238] are investigated with various XC functionals. Taking the MRCISD+Q (multireference configuration interaction with singles and doubles plus the Davidson correction) results as benchmark, it is found that the mean absolute errors of SF-TDA/ALDA0 with the SAOP (statistical averaging of model orbital potentials), global hybrid, and range-separated hybrid functionals are in the range of 0.2-0.4 eV. This is in line not only with the typical accuracy of TD-DFT for singlet and triplet excited states of closed-shell systems but also with the gross accuracy of spin-adapted TD-DFT for spin-conserving excited states of open-shell systems. PMID

  5. Critical Assessment of Time-Dependent Density Functional Theory for Excited States of Open-Shell Systems: II. Doublet-Quartet Transitions.

    PubMed

    Li, Zhendong; Liu, Wenjian

    2016-06-14

    Compared with closed-shell systems, open-shell systems place three additional challenges to time-dependent density functional theory (TD-DFT) for electronically excited states: (a) the spin-contamination problem is a serious issue; (b) the exchange-correlation (XC) kernel may be numerically instable; and (c) the single-determinant description of open-shell ground states readily becomes energetically instable. Confined to flip-up single excitations, the spin-contamination problem can largely be avoided by using the spin-flip TD-DFT (SF-TD-DFT) formalism, provided that a noncollinear XC kernel is employed. As for the numerical instabilities associated with such a kernel, only an ad hoc scheme has been proposed so far, viz., the ALDA0 kernel, which amounts to setting the divergent components (arising from density gradients and kinetic energy density) simply to zero. The ground-state instability problem can effectively be avoided by introducing the Tamm-Dancoff approximation (TDA) to TD-DFT. Therefore, on a general basis, the SF-TDA/ALDA0 Ansatz is so far the only promising means within the TD-DFT framework for flip-up single excitations of open-shell systems. To assess systematically the performance of SF-TDA/ALDA0, in total 61 low-lying quartet excited states of the benchmark set of 11 small radicals [J. Chem. Theory Comput. 2016, 12, 238] are investigated with various XC functionals. Taking the MRCISD+Q (multireference configuration interaction with singles and doubles plus the Davidson correction) results as benchmark, it is found that the mean absolute errors of SF-TDA/ALDA0 with the SAOP (statistical averaging of model orbital potentials), global hybrid, and range-separated hybrid functionals are in the range of 0.2-0.4 eV. This is in line not only with the typical accuracy of TD-DFT for singlet and triplet excited states of closed-shell systems but also with the gross accuracy of spin-adapted TD-DFT for spin-conserving excited states of open-shell systems.

  6. Critical Pedagogy for Critical Mathematics Education

    ERIC Educational Resources Information Center

    Tutak, Fatma Aslan; Bondy, Elizabeth; Adams, Thomasenia L.

    2011-01-01

    This article provides a brief introduction to critical pedagogy and further discussion on critical mathematics education. Critical mathematics education enables students to read the world with mathematics. Three emerging domains of mathematics education related to critical mathematics education are discussed in this manuscript: ethnomathematics,…

  7. CCSDS Time-Critical Onboard Networking Service

    NASA Technical Reports Server (NTRS)

    Parkes, Steve; Schnurr, Rick; Marquart, Jane; Menke, Greg; Ciccone, Massimiliano

    2006-01-01

    The Consultative Committee for Space Data Systems (CCSDS) is developing recommendations for communication services onboard spacecraft. Today many different communication buses are used on spacecraft requiring software with the same basic functionality to be rewritten for each type of bus. This impacts on the application software resulting in custom software for almost every new mission. The Spacecraft Onboard Interface Services (SOIS) working group aims to provide a consistent interface to various onboard buses and sub-networks, enabling a common interface to the application software. The eventual goal is reusable software that can be easily ported to new missions and run on a range of onboard buses without substantial modification. The system engineer will then be able to select a bus based on its performance, power, etc and be confident that a particular choice of bus will not place excessive demands on software development. This paper describes the SOIS Intra-Networking Service which is designed to enable data transfer and multiplexing of a variety of internetworking protocols with a range of quality of service support, over underlying heterogeneous data links. The Intra-network service interface provides users with a common Quality of Service interface when transporting data across a variety of underlying data links. Supported Quality of Service (QoS) elements include: Priority, Resource Reservation and Retry/Redundancy. These three QoS elements combine and map into four TCONS services for onboard data communications: Best Effort, Assured, Reserved, and Guaranteed. Data to be transported is passed to the Intra-network service with a requested QoS. The requested QoS includes the type of service, priority and where appropriate, a channel identifier. The data is de-multiplexed, prioritized, and the required resources for transport are allocated. The data is then passed to the appropriate data link for transfer across the bus. The SOIS supported data links may inherently provide the quality of service support requested by the intra-network layer. In the case where the data link does not have the required level of support, the missing functionality is added by SOIS. As a result of this architecture, re-usable software applications can be designed and used across missions thereby promoting common mission operations. In addition, the protocol multiplexing function enables the blending of multiple onboard networks. This paper starts by giving an overview of the SOIS architecture in section 11, illustrating where the TCONS services fit into the overall architecture. It then describes the quality of service approach adopted, in section III. The prototyping efforts that have been going on are introduced in section JY. Finally, in section V the current status of the CCSDS recommendations is summarized.

  8. Deconfined quantum critical points.

    PubMed

    Senthil, T; Vishwanath, Ashvin; Balents, Leon; Sachdev, Subir; Fisher, Matthew P A

    2004-03-01

    The theory of second-order phase transitions is one of the foundations of modern statistical mechanics and condensed-matter theory. A central concept is the observable order parameter, whose nonzero average value characterizes one or more phases. At large distances and long times, fluctuations of the order parameter(s) are described by a continuum field theory, and these dominate the physics near such phase transitions. We show that near second-order quantum phase transitions, subtle quantum interference effects can invalidate this paradigm, and we present a theory of quantum critical points in a variety of experimentally relevant two-dimensional antiferromagnets. The critical points separate phases characterized by conventional "confining" order parameters. Nevertheless, the critical theory contains an emergent gauge field and "deconfined" degrees of freedom associated with fractionalization of the order parameters. We propose that this paradigm for quantum criticality may be the key to resolving a number of experimental puzzles in correlated electron systems and offer a new perspective on the properties of complex materials.

  9. Critical Viewing: Stimulant to Critical Thinking.

    ERIC Educational Resources Information Center

    O'Reilly, Kevin; Splaine, John

    This document is intended to improve the critical viewing skills and increase the understanding and appreciation of what is viewed. Included are the chapters: (1) "Critical Thinking: The Parts of an Argument," intended to develop a process to help a person judge arguments in what is read, seen, and heard; (2) "Critical Viewing: Concepts, Skills,…

  10. Critical Thinking in Adulthood.

    ERIC Educational Resources Information Center

    Fulton, Rodney D.

    Critical thinking is often defined as that which a particular instrument measures. The most prominent tests are the Watson-Glaser Critical Thinking Appraisal, the Ennis-Weir Critical Thinking Essay Test, and the Cornell Critical Thinking Tests. Watson and Glaser's (1980) view of critical thinking is "a composite of attitudes, knowledge, and…

  11. Subduction of Young Lithosphere at Critical Thermal Ages (10-20 Ma): Incites From Thermal Models and the Trans-Mexican Subduction System with Emphasis on the Importance of Slab Travel Times

    NASA Astrophysics Data System (ADS)

    Grose, C. J.

    2007-12-01

    The Trans-Mexican Volcanic Belt (TMVB) is a system where the age range of subducting plates is typically thought of as critical in their relation to lithospheric thermal structure (~10-20 Ma). I refer to this age range as "critical" because it is in this range where thermal lithospheres begin to rapidly decrease their correlative influence on the thermal state of the subduction system above the crust/mantle wedge interface for most systems. After ~20 Ma the cool upper portion of downgoing lithosphere becomes sufficiently thick so that crustal reheating and corresponding heat flow in the time between trench subduction and the zone of melt generation, due to the accumulation of conductive and frictional heating, behaves somewhat similarly with little regard to age. Typical slab travel times are on the order of 1.5-2.5 My. However, low dip angles and flat-slab behavior in the Eastern end of the TMVB facilitates anomalously long travel times exceeding 6.5 My! Here I show that while the influence of plate age is clearly significant in determining the holistic thermal geodynamics of subduction systems, the influence can be dampened or enhanced by auxiliary factors. I present thermal modeling cases using a solution for the conduction of heat into an evolving semi-infinite half-space with variable boundary conditions. Preliminary results indicate that extraordinary slab travel times and flat-slab behavior, mantle wedge advection regimes, and plate age thermally enhance and dampen each other. Geochemically, the TMVB shows consistent along-arc changes in light element abundance systematics (B/Be, Li/Yb, Be/Zr). Moderately elevated B/Be (Easterly increases from ~4 to ~12 ppm B/Be) observed in the eastern shallow subduction region is thought to correlate with subduction of an older, cooler portion of the slab. However, greater slab travel times in the Eastern TVMB should simultaneously act to warm the slab and depreciate these values which may partly explain the minimal

  12. Critical Care in Critical Access Hospitals.

    PubMed

    Seright, Teresa J; Winters, Charlene A

    2015-10-01

    What began as a grant-funded demonstration project, as a means of bridging the gap in rural health care, has developed into a critical access hospital system comprising 1328 facilities across 45 states. A critical access hospital is not just a safety net for health care in a rural community. Such hospitals may also provide specialized services such as same-day surgery, infusion therapy, and intensive care. For hospitals located near the required minimum of 35 miles from a tertiary care center, management of critically ill patients may be a matter of stabilization and transfer. Critical access hospitals in more rural areas are often much farther from tertiary care; some of these hospitals are situated within frontier areas of the United States. This article describes the development of critical access hospitals, provision of care and services, challenges to critical care in critical access hospitals, and suggestions to address gaps in research and collaborative care.

  13. The Sick and the Weak: Neuropathies/Myopathies in the Critically Ill

    PubMed Central

    Friedrich, O.; Reid, M. B.; Van den Berghe, G.; Vanhorebeek, I.; Hermans, G.; Rich, M. M.; Larsson, L.

    2015-01-01

    Critical illness polyneuropathies (CIP) and myopathies (CIM) are common complications of critical illness. Several weakness syndromes are summarized under the term intensive care unit-acquired weakness (ICUAW). We propose a classification of different ICUAW forms (CIM, CIP, sepsis-induced, steroid-denervation myopathy) and pathophysiological mechanisms from clinical and animal model data. Triggers include sepsis, mechanical ventilation, muscle unloading, steroid treatment, or denervation. Some ICUAW forms require stringent diagnostic features; CIM is marked by membrane hypoexcitability, severe atrophy, preferential myosin loss, ultrastructural alterations, and inadequate autophagy activation while myopathies in pure sepsis do not reproduce marked myosin loss. Reduced membrane excitability results from depolarization and ion channel dysfunction. Mitochondrial dysfunction contributes to energy-dependent processes. Ubiquitin proteasome and calpain activation trigger muscle proteolysis and atrophy while protein synthesis is impaired. Myosin loss is more pronounced than actin loss in CIM. Protein quality control is altered by inadequate autophagy. Ca2+ dysregulation is present through altered Ca2+ homeostasis. We highlight clinical hallmarks, trigger factors, and potential mechanisms from human studies and animal models that allow separation of risk factors that may trigger distinct mechanisms contributing to weakness. During critical illness, altered inflammatory (cytokines) and metabolic pathways deteriorate muscle function. ICUAW prevention/treatment is limited, e.g., tight glycemic control, delaying nutrition, and early mobilization. Future challenges include identification of primary/secondary events during the time course of critical illness, the interplay between membrane excitability, bioenergetic failure and differential proteolysis, and finding new therapeutic targets by help of tailored animal models. PMID:26133937

  14. Gradient liquid chromatographic retention time prediction for suspect screening applications: A critical assessment of a generalised artificial neural network-based approach across 10 multi-residue reversed-phase analytical methods.

    PubMed

    Barron, Leon P; McEneff, Gillian L

    2016-01-15

    For the first time, the performance of a generalised artificial neural network (ANN) approach for the prediction of 2492 chromatographic retention times (tR) is presented for a total of 1117 chemically diverse compounds present in a range of complex matrices and across 10 gradient reversed-phase liquid chromatography-(high resolution) mass spectrometry methods. Probabilistic, generalised regression, radial basis function as well as 2- and 3-layer multilayer perceptron-type neural networks were investigated to determine the most robust and accurate model for this purpose. Multi-layer perceptrons most frequently yielded the best correlations in 8 out of 10 methods. Averaged correlations of predicted versus measured tR across all methods were R(2)=0.918, 0.924 and 0.898 for the training, verification and test sets respectively. Predictions of blind test compounds (n=8-84 cases) resulted in an average absolute accuracy of 1.02±0.54min for all methods. Within this variation, absolute accuracy was observed to marginally improve for shorter runtimes, but was found to be relatively consistent with respect to analyte retention ranges (~5%). Finally, optimised and replicated network dependency on molecular descriptor data is presented and critically discussed across all methods. Overall, ANNs were considered especially suitable for suspects screening applications and could potentially be utilised in bracketed-type analyses in combination with high resolution mass spectrometry. PMID:26592605

  15. Time evolution of dynamic shear moduli in a physical gelation process of 1,3:2,4-bis-O-(p-methylbenzylidene)-D-sorbitol in polystyrene melt: Critical exponent and gel strength

    NASA Astrophysics Data System (ADS)

    Takenaka, Mikihito; Kobayashi, Toshiaki; Hashimoto, Takeji; Takahashi, Masaoki

    2002-04-01

    We investigated time evolution of shear moduli in the physical gelation process of 1,3:2,4-bis-O-(p-methylbenzylidene)-D-sorbitol (PDTS) in the polystyrene melt system containing 2.5 wt % of PDTS. At the gel point, storage and loss shear moduli, G' and G″, were described by the power law of frequency ω, G'˜G″˜ωn, with the critical exponent n equal to (2)/(3), in agreement with the value predicted by the percolation theory. The exponent n and the gel strength S at the gel point measured as a function of quench depth ΔT indicated that the fractal network structure of PDTS does not change with ΔT but that the mechanical strength of the network increases with ΔT. Before reaching the gel point, G'(ω) and G″(ω) obtained at various times can be well superposed onto the master curves, indicating that the mechanical as well as structural self-similarity hold in this gelation process.

  16. Gradient liquid chromatographic retention time prediction for suspect screening applications: A critical assessment of a generalised artificial neural network-based approach across 10 multi-residue reversed-phase analytical methods.

    PubMed

    Barron, Leon P; McEneff, Gillian L

    2016-01-15

    For the first time, the performance of a generalised artificial neural network (ANN) approach for the prediction of 2492 chromatographic retention times (tR) is presented for a total of 1117 chemically diverse compounds present in a range of complex matrices and across 10 gradient reversed-phase liquid chromatography-(high resolution) mass spectrometry methods. Probabilistic, generalised regression, radial basis function as well as 2- and 3-layer multilayer perceptron-type neural networks were investigated to determine the most robust and accurate model for this purpose. Multi-layer perceptrons most frequently yielded the best correlations in 8 out of 10 methods. Averaged correlations of predicted versus measured tR across all methods were R(2)=0.918, 0.924 and 0.898 for the training, verification and test sets respectively. Predictions of blind test compounds (n=8-84 cases) resulted in an average absolute accuracy of 1.02±0.54min for all methods. Within this variation, absolute accuracy was observed to marginally improve for shorter runtimes, but was found to be relatively consistent with respect to analyte retention ranges (~5%). Finally, optimised and replicated network dependency on molecular descriptor data is presented and critically discussed across all methods. Overall, ANNs were considered especially suitable for suspects screening applications and could potentially be utilised in bracketed-type analyses in combination with high resolution mass spectrometry.

  17. Critical Materials Institute

    ScienceCinema

    Alex King

    2016-07-12

    Ames Laboratory Director Alex King talks about the goals of the Critical Materials Institute in diversifying the supply of critical materials, developing substitute materials, developing tools and techniques for recycling critical materials, and forecasting materials needs to avoid future shortages.

  18. Critical Materials Institute

    SciTech Connect

    Alex King

    2013-01-09

    Ames Laboratory Director Alex King talks about the goals of the Critical Materials Institute in diversifying the supply of critical materials, developing substitute materials, developing tools and techniques for recycling critical materials, and forecasting materials needs to avoid future shortages.

  19. Critical Care Team

    MedlinePlus

    ... Please enable scripts and reload this page. About Critical Care Currently selected Team Questions During the ICU Chronic ... Team Currently selected Questions Patients and Families > About Critical Care > Team Tweet Team Page Content ​The critical care ...

  20. Adaptive critics for dynamic optimization.

    PubMed

    Kulkarni, Raghavendra V; Venayagamoorthy, Ganesh Kumar

    2010-06-01

    A novel action-dependent adaptive critic design (ACD) is developed for dynamic optimization. The proposed combination of a particle swarm optimization-based actor and a neural network critic is demonstrated through dynamic sleep scheduling of wireless sensor motes for wildlife monitoring. The objective of the sleep scheduler is to dynamically adapt the sleep duration to node's battery capacity and movement pattern of animals in its environment in order to obtain snapshots of the animal on its trajectory uniformly. Simulation results show that the sleep time of the node determined by the actor critic yields superior quality of sensory data acquisition and enhanced node longevity. PMID:20223635

  1. Frailty in Pulmonary and Critical Care Medicine.

    PubMed

    Singer, Jonathan P; Lederer, David J; Baldwin, Matthew R

    2016-08-01

    Conceptualized first in the field of geriatrics, frailty is a syndrome characterized by a generalized vulnerability to stressors resulting from an accumulation of physiologic deficits across multiple interrelated systems. This accumulation of deficits results in poorer functional status and disability. Frailty is a "state of risk" for subsequent disproportionate declines in health status following new exposure to a physiologic stressor. Two predominant models have emerged to operationalize the measurement of frailty. The phenotype model defines frailty as a distinct clinical syndrome that includes conceptual domains such as strength, activity, wasting, and mobility. The cumulative deficit model defines frailty by enumerating the number of age-related things wrong with a person. The biological pathways driving frailty include chronic systemic inflammation, sarcopenia, and neuroendocrine dysregulation, among others. In adults with chronic lung disease, frailty is independently associated with more frequent exacerbations of lung disease, all-cause hospitalization, declines in functional status, and all-cause mortality. In addition, frail adults who become critically ill are more likely develop chronic critical illness or severe disability and have higher in-hospital and long-term mortality rates. The evaluation of frailty appears to provide important prognostic information above and beyond routinely collected measures in adults with chronic lung disease and the critically ill. The study of frailty in these populations, however, requires multipronged efforts aimed at refining clinical assessments, understanding the mechanisms, and developing therapeutic interventions. PMID:27104873

  2. Frailty in Pulmonary and Critical Care Medicine.

    PubMed

    Singer, Jonathan P; Lederer, David J; Baldwin, Matthew R

    2016-08-01

    Conceptualized first in the field of geriatrics, frailty is a syndrome characterized by a generalized vulnerability to stressors resulting from an accumulation of physiologic deficits across multiple interrelated systems. This accumulation of deficits results in poorer functional status and disability. Frailty is a "state of risk" for subsequent disproportionate declines in health status following new exposure to a physiologic stressor. Two predominant models have emerged to operationalize the measurement of frailty. The phenotype model defines frailty as a distinct clinical syndrome that includes conceptual domains such as strength, activity, wasting, and mobility. The cumulative deficit model defines frailty by enumerating the number of age-related things wrong with a person. The biological pathways driving frailty include chronic systemic inflammation, sarcopenia, and neuroendocrine dysregulation, among others. In adults with chronic lung disease, frailty is independently associated with more frequent exacerbations of lung disease, all-cause hospitalization, declines in functional status, and all-cause mortality. In addition, frail adults who become critically ill are more likely develop chronic critical illness or severe disability and have higher in-hospital and long-term mortality rates. The evaluation of frailty appears to provide important prognostic information above and beyond routinely collected measures in adults with chronic lung disease and the critically ill. The study of frailty in these populations, however, requires multipronged efforts aimed at refining clinical assessments, understanding the mechanisms, and developing therapeutic interventions.

  3. Toward Superconducting Critical Current by Design.

    PubMed

    Sadovskyy, Ivan A; Jia, Ying; Leroux, Maxime; Kwon, Jihwan; Hu, Hefei; Fang, Lei; Chaparro, Carlos; Zhu, Shaofei; Welp, Ulrich; Zuo, Jian-Min; Zhang, Yifei; Nakasaki, Ryusuke; Selvamanickam, Venkat; Crabtree, George W; Koshelev, Alexei E; Glatz, Andreas; Kwok, Wai-Kwong

    2016-06-01

    A new critical-current-by-design paradigm is presented. It aims at predicting the optimal defect landscape in superconductors for targeted applications by elucidating the vortex dynamics responsible for the bulk critical current. To this end, critical current measurements on commercial high-temperature superconductors are combined with large-scale time-dependent Ginzburg-Landau simulations of vortex dynamics.

  4. Critical Learning Skills for Business Students

    ERIC Educational Resources Information Center

    Jance, Marsha; Morgan, Anita

    2013-01-01

    A survey addressing critical skills for business students was developed and disseminated. Sixteen critical skills (such as critical thinking and time management) were identified as skills that need to be acquired in order for business students to be successful in their advanced courses and careers. The survey was disseminated and taken by several…

  5. Design of Critical Components

    NASA Technical Reports Server (NTRS)

    Hendricks, Robert C.; Zaretsky, Erwin V.

    2001-01-01

    Critical component design is based on minimizing product failures that results in loss of life. Potential catastrophic failures are reduced to secondary failures where components removed for cause or operating time in the system. Issues of liability and cost of component removal become of paramount importance. Deterministic design with factors of safety and probabilistic design address but lack the essential characteristics for the design of critical components. In deterministic design and fabrication there are heuristic rules and safety factors developed over time for large sets of structural/material components. These factors did not come without cost. Many designs failed and many rules (codes) have standing committees to oversee their proper usage and enforcement. In probabilistic design, not only are failures a given, the failures are calculated; an element of risk is assumed based on empirical failure data for large classes of component operations. Failure of a class of components can be predicted, yet one can not predict when a specific component will fail. The analogy is to the life insurance industry where very careful statistics are book-kept on classes of individuals. For a specific class, life span can be predicted within statistical limits, yet life-span of a specific element of that class can not be predicted.

  6. A Critical Humanist Curriculum

    ERIC Educational Resources Information Center

    Magill, Kevin; Rodriguez, Arturo

    2015-01-01

    This essay is a critical humanist discussion of curriculum; a departure from the technicist view of education [education meant to support a global capitalist economy] and an analysis of curriculum considering critical humanism, political economy and critical race theory among other modes of critical analysis and inquiry. Our discussion supports a…

  7. Social class, ethnicity, and mental illness: the importance of being more than earnest.

    PubMed

    Vander Stoep, A; Link, B

    1998-09-01

    This paper revisits a landmark study of the prevalence of mental illness in the state of Massachusetts conducted by Edward Jarvis in the 19th century. Jarvis drew an improper conclusion about the relationship between social class, ethnicity, and insanity, asserting that the Irish foreign-born had a higher prevalence of insanity in each social stratum. A reanalysis of Jarvis' data shows that in both the pauper and independent social classes in Massachusetts, the prevalence of insanity was significantly lower among foreign-born persons than among native-born persons. On the basis of his misperception, Jarvis constructed elaborate etiological theories. These theories made a strong impact on the mental health service policies of his day. The effects of incomplete examination of data on etiological theories and mental health policy in current times are highlighted in this article.

  8. Addressing public stigma and disparities among persons with mental illness: the role of federal policy.

    PubMed

    Cummings, Janet R; Lucas, Stephen M; Druss, Benjamin G

    2013-05-01

    Stigma against mental illness is a complex construct with affective, cognitive, and behavioral components. Beyond its symbolic value, federal law can only directly address one component of stigma: discrimination. This article reviews three landmark antidiscrimination laws that expanded protections over time for individuals with mental illness. Despite these legislative advances, protections are still not uniform for all subpopulations with mental illness. Furthermore, multiple components of stigma (e.g., prejudice) are beyond the reach of legislation, as demonstrated by the phenomenon of label avoidance; individuals may not seek protection from discrimination because of fear of the stigma that may ensue after disclosing their mental illness. To yield the greatest improvements, antidiscrimination laws must be coupled with antistigma programs that directly address other components of stigma.

  9. Critical Approaches to Critical Pedagogy in Greece

    ERIC Educational Resources Information Center

    Grollios, George; Liambas, Anastassios

    2015-01-01

    This paper is an initial review of the presentations and uses of critical pedagogy in Greek educational literature since the mid-1980s. These have appeared in the form of three books and an edited volume (translated in Greek), all written by American critical educators, as well as in texts produced by Greek educators who have either written the…

  10. A Critical Look into Critical Pedagogy

    ERIC Educational Resources Information Center

    Pishghadam, Reza; Meidani, Elham Naji

    2012-01-01

    In line with postmodern philosophy, critical pedagogy has gained considerable importance and has become a valuable educational goal. The purpose of this study is to dig into the effects of critical pedagogy in a modernist educational system. To this aim, 15 Iranian university students were asked to write down their feelings at the end of a course…

  11. Revalorizing the Critical Attitude for Critical Education

    ERIC Educational Resources Information Center

    Amsler, Sarah S.

    2011-01-01

    This article argues that at a moment of crisis in education, the defence of critical pedagogy is vitally important. However, it also suggests that such a defence should be more than a "cri de coeur" that asserts principles and methods of criticality against those of neoliberal or conservative education policy. Narratives of a totalising "crisis of…

  12. How critical is chronic critical leg ischaemia?

    PubMed

    Kroese, A J; Stranden, E

    1998-01-01

    "Critical" according to the Oxford dictionary means: a "turning point" where an acute change for better or worse may be anticipated. Thus, the meaning of the word "critical" complies with its use in relation to ischaemia. We don't really know, prospectively, what will happen to the critically ischaemic limb, whether it will improve or worsen. The answer to the question "How critical is critical leg ischaemia (CLI)?" must be: "We don't know!" The addition of ankle systolic pressure as an objective haemodynamic measurement has not made the definition of the Second European Consensus Group significantly better than the original Fontaine classification, grade III and IV. For clinical practice the Fontaine classification will be sufficient. For scientific purposes macro- and microcirculatory assessments and information about the patient's risk profile should be added. PMID:9676324

  13. How critical is chronic critical leg ischaemia?

    PubMed

    Kroese, A J; Stranden, E

    1998-01-01

    "Critical" according to the Oxford dictionary means: a "turning point" where an acute change for better or worse may be anticipated. Thus, the meaning of the word "critical" complies with its use in relation to ischaemia. We don't really know, prospectively, what will happen to the critically ischaemic limb, whether it will improve or worsen. The answer to the question "How critical is critical leg ischaemia (CLI)?" must be: "We don't know!" The addition of ankle systolic pressure as an objective haemodynamic measurement has not made the definition of the Second European Consensus Group significantly better than the original Fontaine classification, grade III and IV. For clinical practice the Fontaine classification will be sufficient. For scientific purposes macro- and microcirculatory assessments and information about the patient's risk profile should be added.

  14. [Stigmatization on the way to recovery in mental illness - the factors associated with social functioning].

    PubMed

    Podogrodzka-Niell, Magdalena; Tyszkowska, Magdalena

    2014-01-01

    Persons with mental disorders often experience stigmatization. There is a number of social factors that may affect the process of recovery and at the same time, in certain circumstances, could be a source of stigma. Mentally ill may find strength in themselves to fight against the disease or the opposite - can internalize the negative attitudes of the society and become self-stigmatized. The patient's family, on the one hand, is often the only source of social support, on the other hand, can experience a destructive influence of courtesy-stigma. Mentally ill have to face social reluctance which is reinforced by stereotypical media coverage of mental disorders. The social network of patients is poor and often limited to a family system. Negative views about persons diagnosed with mental illness are most visible in the labour market. Patients experience many types of discrimination at work,have lower employment rates and lower mean wages than healthy ones. Structural discrimination is a form of stigma which is revealed in underfunded and inefficient system of mental health care. All the social factors mentioned above are necessary for recovery (positive stimulation of functioning), but can also increase stigma and become a significant barrier in the recovery of psychiatric patients. This paper highlights the complex and ambiguous nature of the relationship between social factors and the recovery of the mentally ill basing on the data from the literature. PMID:25717489

  15. Autism: a "critical period" disorder?

    PubMed

    LeBlanc, Jocelyn J; Fagiolini, Michela

    2011-01-01

    Cortical circuits in the brain are refined by experience during critical periods early in postnatal life. Critical periods are regulated by the balance of excitatory and inhibitory (E/I) neurotransmission in the brain during development. There is now increasing evidence of E/I imbalance in autism, a complex genetic neurodevelopmental disorder diagnosed by abnormal socialization, impaired communication, and repetitive behaviors or restricted interests. The underlying cause is still largely unknown and there is no fully effective treatment or cure. We propose that alteration of the expression and/or timing of critical period circuit refinement in primary sensory brain areas may significantly contribute to autistic phenotypes, including cognitive and behavioral impairments. Dissection of the cellular and molecular mechanisms governing well-established critical periods represents a powerful tool to identify new potential therapeutic targets to restore normal plasticity and function in affected neuronal circuits.

  16. Individual psychotherapy and persons with serious mental illness: the clients' perspective.

    PubMed

    Coursey, R D; Keller, A B; Farrell, E W

    1995-01-01

    The perspectives of persons with serious mental illness about their experiences with individual psychotherapy were obtained from a stratified random sample of 12 psychosocial rehabilitation centers from all centers in Maryland. Response and completion rates, test-retest reliability, and generalization data were positive. Eight areas were explored: (1) Utilization and duration: of the 212 respondents, 90 percent had been in therapy for a median of 12 months (mean = 3 years); only a third expected to end their therapy within 5 years. (2) Therapeutic effectiveness: most of the respondents (72%) reported that individual psychotherapy had brought positive changes to their lives, 14 percent reported negative changes, and 14 percent reported that therapy had had no effect. (3) Preferred interventions and parameters: sixteen percent felt that medication was most useful, 25 percent felt that talking therapy was most useful, and 60 percent endorsed a combination of the two. With respect to diagnosis and psychotherapy, 84 percent of respondents with schizophrenia preferred brief, less frequent sessions of reality-oriented therapy over longer, more frequent sessions of insight therapy. Respondents with bipolar and major depression were equally split between the two. (4) Therapeutic issues: human concerns were more frequently rated as important and were rated higher in importance than illness-specific symptoms. (5) Clients' view of illness: Only 8 percent thought their illness was a brain disease, a third thought it was a psychological problem, and a quarter thought it was a combination of both; a third answered, open quote I don't know closed quote. Almost half did not know what their therapists thought. (6) Therapeutic relationship: Friendliness was the quality most desired in a therapist. (7) Confidentiality: Most felt that therapists generally kept the clients' confidences. (8) Empowerment: Persons who felt empowered in therapy spent less time in hospitals, expected a

  17. Superstatistics and renewal critical events

    NASA Astrophysics Data System (ADS)

    Paradisi, Paolo; Cesari, Rita; Grigolini, Paolo

    2009-09-01

    An approach to intermittent systems based on renewal processes is reviewed. The Waiting Times (WTs) between events are the main variables of interest in intermittent systems. A crucial role is played by the class of critical events, characterized by Non-Poisson statistics and non-exponential WT distribution. A particular important case is given by WT distributions with power tail. Critical events play a crucial role in the behavior of a property known as Renewal Aging. Focusing on the role of critical events, the relation between superstatistics and non-homogeneous Poisson processes is discussed, and the role of Renewal Aging is illustrated by comparing a Non-Poisson model with a Poisson one, both of them modulated by a periodic forcing. It is shown that the analysis of Renewal Aging is sensitive to the presence of critical events and that this property can be exploited to detect Non-Poisson statistics in a time series. As a consequence, it is claimed that, apart from the characterization of superstatistical features such as the distribution of the intensive parameter or the separation of the time scales, the Renewal Aging property can give some effort to better determine the role of Non-Poisson critical events in intermittent systems.

  18. Safety Critical Mechanisms

    NASA Technical Reports Server (NTRS)

    Robertson, Brandan

    2008-01-01

    Spaceflight mechanisms have a reputation for being difficult to develop and operate successfully. This reputation is well earned. Many circumstances conspire to make this so: the environments in which the mechanisms are used are extremely severe, there is usually limited or no maintenance opportunity available during operation due to this environment, the environments are difficult to replicate accurately on the ground, the expense of the mechanism development makes it impractical to build and test many units for long periods of time before use, mechanisms tend to be highly specialized and not prone to interchangeability or off-the-shelf use, they can generate and store a lot of energy, and the nature of mechanisms themselves, as a combination of structures, electronics, etc. designed to accomplish specific dynamic performance, makes them very complex and subject to many unpredictable interactions of many types. In addition to their complexities, mechanism are often counted upon to provide critical vehicle functions that can result in catastrophic events should the functions not be performed. It is for this reason that mechanisms are frequently subjected to special scrutiny in safety processes. However, a failure tolerant approach, along with good design and development practices and detailed design reviews, can be developed to allow such notoriously troublesome mechanisms to be utilized confidently in safety-critical applications.

  19. Antibiotic dose optimization in critically ill patients.

    PubMed

    Cotta, M O; Roberts, J A; Lipman, J

    2015-12-01

    The judicious use of existing antibiotics is essential for preserving their activity against infections. In the era of multi-drug resistance, this is of particular importance in clinical areas characterized by high antibiotic use, such as the ICU. Antibiotic dose optimization in critically ill patients requires sound knowledge not only of the altered physiology in serious infections - including severe sepsis, septic shock and ventilator-associated pneumonia - but also of the pathogen-drug exposure relationship (i.e. pharmacokinetic/pharmacodynamic index). An important consideration is the fact that extreme shifts in organ function, such as those seen in hyperdynamic patients or those with multiple organ dysfunction syndrome, can have an impact upon drug exposure, and constant vigilance is required when reviewing antibiotic dosing regimens in the critically ill. The use of continuous renal replacement therapy and extracorporeal membrane oxygenation remain important interventions in these patients; however, both of these treatments can have a profound effect on antibiotic exposure. We suggest placing emphasis on the use of therapeutic drug monitoring and dose individualization when optimizing therapy in these settings.

  20. Critical Infrastructure Modeling System

    2004-10-01

    The Critical Infrastructure Modeling System (CIMS) is a 3D modeling and simulation environment designed to assist users in the analysis of dependencies within individual infrastructure and also interdependencies between multiple infrastructures. Through visual cuing and textual displays, a use can evaluate the effect of system perturbation and identify the emergent patterns that evolve. These patterns include possible outage areas from a loss of power, denial of service or access, and disruption of operations. Method ofmore » Solution: CIMS allows the user to model a system, create an overlay of information, and create 3D representative images to illustrate key infrastructure elements. A geo-referenced scene, satellite, aerial images or technical drawings can be incorporated into the scene. Scenarios of events can be scripted, and the user can also interact during run time to alter system characteristics. CIMS operates as a discrete event simulation engine feeding a 3D visualization.« less

  1. Critical anthropometry for menarche.

    PubMed

    Gonzales, G F; Villena, A

    1996-08-01

    The objective of the study was to determine if any anthropometric measurements, including weight, height, and upper arm circumference, or the calculated body mass index observed at the time of menarche may be used as a threshold for menarche. The sample was randomly selected from 1133 girls aged 10-18 years from two groups, one residing in Lima, Peru, at 150 m above sea level, and the second in Cerro de Pasco, Peru, at 4340 m above sea level. For the purpose of this study, all girls who reached menarche at least 1 month before the study (n = 93) were considered as cases (girls at menarche); 88 girls without menarche at the time of the study were randomly matched by age and place of residence, and designated as controls. All subjects came from the same low socioeconomic status. Body weight at menarche was 44.6 +/- 5.09 kg (mean +/- SD; coefficient of variation [CV], 11.4%). Height at menarche was 151.6 +/- 5.5 cm (CV, 3.7%). Body mass index, defined as weight/height2.15, was 18.26 +/- 1.96 kg/m2.15 at menarche (CV, 10.7%). Upper arm circumference at menarche was 21.8 +/- 1.6 cm (CV, 7.3%). The logistic regression analysis showed that any of the four anthropometric measurements analyzed were critical for menarche; i.e., any of the four could be used as a threshold for menarche. Data from the present study do not support the hypothesis that there are anthropometric markers that are critical for menarche.

  2. Anomalous critical fields in quantum critical superconductors.

    PubMed

    Putzke, C; Walmsley, P; Fletcher, J D; Malone, L; Vignolles, D; Proust, C; Badoux, S; See, P; Beere, H E; Ritchie, D A; Kasahara, S; Mizukami, Y; Shibauchi, T; Matsuda, Y; Carrington, A

    2014-01-01

    Fluctuations around an antiferromagnetic quantum critical point (QCP) are believed to lead to unconventional superconductivity and in some cases to high-temperature superconductivity. However, the exact mechanism by which this occurs remains poorly understood. The iron-pnictide superconductor BaFe2(As(1-x)P(x))2 is perhaps the clearest example to date of a high-temperature quantum critical superconductor, and so it is a particularly suitable system to study how the quantum critical fluctuations affect the superconducting state. Here we show that the proximity of the QCP yields unexpected anomalies in the superconducting critical fields. We find that both the lower and upper critical fields do not follow the behaviour, predicted by conventional theory, resulting from the observed mass enhancement near the QCP. Our results imply that the energy of superconducting vortices is enhanced, possibly due to a microscopic mixing of antiferromagnetism and superconductivity, suggesting that a highly unusual vortex state is realized in quantum critical superconductors. PMID:25477044

  3. Anomalous critical fields in quantum critical superconductors

    PubMed Central

    Putzke, C.; Walmsley, P.; Fletcher, J. D.; Malone, L.; Vignolles, D.; Proust, C.; Badoux, S.; See, P.; Beere, H. E.; Ritchie, D. A.; Kasahara, S.; Mizukami, Y.; Shibauchi, T.; Matsuda, Y.; Carrington, A.

    2014-01-01

    Fluctuations around an antiferromagnetic quantum critical point (QCP) are believed to lead to unconventional superconductivity and in some cases to high-temperature superconductivity. However, the exact mechanism by which this occurs remains poorly understood. The iron-pnictide superconductor BaFe2(As1−xPx)2 is perhaps the clearest example to date of a high-temperature quantum critical superconductor, and so it is a particularly suitable system to study how the quantum critical fluctuations affect the superconducting state. Here we show that the proximity of the QCP yields unexpected anomalies in the superconducting critical fields. We find that both the lower and upper critical fields do not follow the behaviour, predicted by conventional theory, resulting from the observed mass enhancement near the QCP. Our results imply that the energy of superconducting vortices is enhanced, possibly due to a microscopic mixing of antiferromagnetism and superconductivity, suggesting that a highly unusual vortex state is realized in quantum critical superconductors. PMID:25477044

  4. Man and Machines: Three Criticisms.

    ERIC Educational Resources Information Center

    Schneider, Edward F.

    As machines have become a more common part of daily life through the passage of time, the idea that the line separating man and machine is slowly fading has become more popular as well. This paper examines three critics of change through their most famous works. One of the most popular views of Mary Shelley's "Frankenstein" is that it is a…

  5. Low-temperature growth and critical epitaxial thicknesses of fully strained metastable Ge{sub 1{minus}x}Sn{sub x} (x{approx_lt}0.26) alloys on Ge(001)2{times}1

    SciTech Connect

    Gurdal, O.; Desjardins, P.; Carlsson, J.R.; Taylor, N.; Radamson, H.H.; Sundgren, J.; Greene, J.E.

    1998-01-01

    Epitaxial metastable Ge{sub 1{minus}x}Sn{sub x} alloys with x up to 0.26 (the equilibrium solid solubility of Sn in Ge is {lt}0.01) were grown on Ge(001)2{times}1 by low-temperature molecular beam epitaxy. Film growth temperatures T{sub s} in these experiments were limited to a relatively narrow range around 100{degree}C by the combination of increased kinetic surface roughening at low temperatures and Sn surface segregation at high temperatures. All Ge{sub 1{minus}x}Sn{sub x} films consisted of three distinct sublayers: the first is a highly perfect epitaxial region followed by a sublayer, with an increasingly rough surface, containing 111 stacking faults and microtwins, while the terminal sublayer is amorphous. Based upon reflection high energy electron diffraction and cross-sectional transmission electron microscopy (XTEM) analyses, critical epitaxial thicknesses t{sub epi}, defined as the onset of amorphous growth, were found to decrease from 1080 {Angstrom} for pure Ge to {approx_equal}35{Angstrom} for alloys with x=0.26. TEM and XTEM analyses revealed no indication of misfit dislocations (except in Ge{sub 0.74}Sn{sub 0.26} samples) and high-resolution x-ray reciprocal lattice mapping showed that epitaxial Ge{sub 1{minus}x}Sn{sub x} layers were essentially fully strained. From an analysis of t{sub epi}(x) results, surface morphological evolution leading to epitaxial breakdown is controlled by kinetic roughening for alloys with x{approx_lt}0.09 and by strain-induced roughening at higher Sn concentrations. We propose that the thermal activation required for the cross-over, reported here for the first time, from kinetic to strain-induced roughening is partially overcome by the fact that kinetic roughening provides local surface chemical potential gradients over lateral length scales which are sufficiently small to initiate strain-induced roughening even at these low temperatures. {copyright} {ital 1998 American Institute of Physics.}

  6. Toward critical bioethics.

    PubMed

    Árnason, Vilhjálmur

    2015-04-01

    This article deals with the question as to what makes bioethics a critical discipline. It considers different senses of criticism and evaluates their strengths and weaknesses. A primary method in bioethics as a philosophical discipline is critical thinking, which implies critical evaluation of concepts, positions, and arguments. It is argued that the type of analytical criticism that restricts its critical role to critical thinking of this type often suffers from other intellectual flaws. Three examples are taken to demonstrate this: premature criticism, uncritical self-understanding of theoretical assumptions, and narrow framing of bioethical issues. Such flaws can lead both to unfair treatment of authors and to uncritical discussion of topics. In this context, the article makes use of Häyry's analysis of different rationalities in bioethical approaches and argues for the need to recognize the importance of communicative rationality for critical bioethics. A radically different critical approach in bioethics, rooted in social theory, focuses on analyses of power relations neglected in mainstream critical thinking. It is argued that, although this kind of criticism provides an important alternative in bioethics, it suffers from other shortcomings that are rooted in a lack of normative dimensions. In order to complement these approaches and counter their shortcomings, there is a need for a bioethics enlightened by critical hermeneutics. Such hermeneutic bioethics is aware of its own assumptions, places the issues in a wide context, and reflects critically on the power relations that stand in the way of understanding them. Moreover, such an approach is dialogical, which provides both a critical exercise of speech and a normative dimension implied in the free exchange of reasons and arguments. This discussion is framed by Hedgecoe's argument that critical bioethics needs four elements: to be empirically rooted, theory challenging, reflexive, and politely skeptical.

  7. Toward critical bioethics.

    PubMed

    Árnason, Vilhjálmur

    2015-04-01

    This article deals with the question as to what makes bioethics a critical discipline. It considers different senses of criticism and evaluates their strengths and weaknesses. A primary method in bioethics as a philosophical discipline is critical thinking, which implies critical evaluation of concepts, positions, and arguments. It is argued that the type of analytical criticism that restricts its critical role to critical thinking of this type often suffers from other intellectual flaws. Three examples are taken to demonstrate this: premature criticism, uncritical self-understanding of theoretical assumptions, and narrow framing of bioethical issues. Such flaws can lead both to unfair treatment of authors and to uncritical discussion of topics. In this context, the article makes use of Häyry's analysis of different rationalities in bioethical approaches and argues for the need to recognize the importance of communicative rationality for critical bioethics. A radically different critical approach in bioethics, rooted in social theory, focuses on analyses of power relations neglected in mainstream critical thinking. It is argued that, although this kind of criticism provides an important alternative in bioethics, it suffers from other shortcomings that are rooted in a lack of normative dimensions. In order to complement these approaches and counter their shortcomings, there is a need for a bioethics enlightened by critical hermeneutics. Such hermeneutic bioethics is aware of its own assumptions, places the issues in a wide context, and reflects critically on the power relations that stand in the way of understanding them. Moreover, such an approach is dialogical, which provides both a critical exercise of speech and a normative dimension implied in the free exchange of reasons and arguments. This discussion is framed by Hedgecoe's argument that critical bioethics needs four elements: to be empirically rooted, theory challenging, reflexive, and politely skeptical

  8. Foundations for Critical Thinking

    ERIC Educational Resources Information Center

    Bers, Trudy; Chun, Marc; Daly, William T.; Harrington, Christine; Tobolowsky, Barbara F.

    2015-01-01

    "Foundations for Critical Thinking" explores the landscape of critical-thinking skill development and pedagogy through foundational chapters and institutional case studies involving a range of students in diverse settings. By establishing a link between active learning and improved critical thinking, this resource encourages all higher…

  9. Reimagining Critical Theory

    ERIC Educational Resources Information Center

    Rexhepi, Jevdet; Torres, Carlos Alberto

    2011-01-01

    This paper discusses Critical Theory, a model of theorizing in the field of the political sociology of education. We argue for a "reimagined" Critical Theory to herald an empowering, liberatory education that fosters curiosity and critical thinking, and a means for successful bottom-up, top-down political engagement. We present arguments at a…

  10. Teaching Critical Reflection

    ERIC Educational Resources Information Center

    Smith, Elizabeth

    2011-01-01

    Despite long-standing commitment to the notion of critical reflection across the healthcare professions it is unusual for critical theory and practice to be taught as explicit subjects in healthcare higher education. There is evidence to show that reflective techniques such as critical portfolios and reflective diaries can help students to…

  11. Reconceptualising Critical Digital Literacy

    ERIC Educational Resources Information Center

    Pangrazio, Luciana

    2016-01-01

    While it has proved a useful concept during the past 20 years, the notion of "critical digital literacy" requires rethinking in light of the fast-changing nature of young people's digital practices. This paper contrasts long-established notions of "critical digital literacy" (based primarily around the critical consumption of…

  12. Writing the Word and the World: Critical Literacy as Critical Textual Production.

    ERIC Educational Resources Information Center

    Morrell, Ernest

    Critical pedagogy is fundamentally and ultimately linked with critical literacy. There can be no liberation of self or other without tools or language to perform counter-readings of dominant texts that serve the interests of power. Paulo Freire and Donaldo Macedo's work has, for some time, been a cornerstone for critical literacy, a model of…

  13. Criticality and unpredictability in macroevolution

    NASA Astrophysics Data System (ADS)

    Soléand, Ricard V.; Manrubia, Susanna C.

    1997-04-01

    A recently presented model of large-scale evolution exhibiting self-organized criticality is explored from the dynamical point of view. It is shown that the system approaches the critical state in an anomalous way, with a dynamical exponent z=0. At the same time, the complexity of the interactions among species increases, leading to higher unpredictability. The dynamic evolution is able to generate phylogenetic fractal trees with dimension close to the one obtained from real taxonomy. Some analytic results are presented and an interesting interpretation of the macroevolutionary process is suggested.

  14. Criticality measurements for SNM accountability

    SciTech Connect

    Bohman, J.; Martin, E.R.; Butterfield, K.; Paternoster, R.

    1998-03-01

    Based on extensive operating experience with the Godiva IV fast metal burst assembly at Los Alamos National Laboratory, the authors were able to create data plots for reactivity worths of standard configurations at various temperatures and room return locations. These plots show that the material uncertainties in criticality measurements are within {+-} 20 grams out of the 65.4 kilogram HEU Godiva core. This is superior to active neutron well coincidence counter (AWCC) measurements. The criticality measurements have the additional advantage of not requiring disassembly of the reactor. No disassembly means the measurement takes less time--it can be done during each operation--and there is less dose to measurement personnel.

  15. Teaching critical thinking

    PubMed Central

    Holmes, N. G.; Wieman, Carl E.; Bonn, D. A.

    2015-01-01

    The ability to make decisions based on data, with its inherent uncertainties and variability, is a complex and vital skill in the modern world. The need for such quantitative critical thinking occurs in many different contexts, and although it is an important goal of education, that goal is seldom being achieved. We argue that the key element for developing this ability is repeated practice in making decisions based on data, with feedback on those decisions. We demonstrate a structure for providing suitable practice that can be applied in any instructional setting that involves the acquisition of data and relating that data to scientific models. This study reports the results of applying that structure in an introductory physics laboratory course. Students in an experimental condition were repeatedly instructed to make and act on quantitative comparisons between datasets, and between data and models, an approach that is common to all science disciplines. These instructions were slowly faded across the course. After the instructions had been removed, students in the experimental condition were 12 times more likely to spontaneously propose or make changes to improve their experimental methods than a control group, who performed traditional experimental activities. The students in the experimental condition were also four times more likely to identify and explain a limitation of a physical model using their data. Students in the experimental condition also showed much more sophisticated reasoning about their data. These differences between the groups were seen to persist into a subsequent course taken the following year. PMID:26283351

  16. Teaching critical thinking.

    PubMed

    Holmes, N G; Wieman, Carl E; Bonn, D A

    2015-09-01

    The ability to make decisions based on data, with its inherent uncertainties and variability, is a complex and vital skill in the modern world. The need for such quantitative critical thinking occurs in many different contexts, and although it is an important goal of education, that goal is seldom being achieved. We argue that the key element for developing this ability is repeated practice in making decisions based on data, with feedback on those decisions. We demonstrate a structure for providing suitable practice that can be applied in any instructional setting that involves the acquisition of data and relating that data to scientific models. This study reports the results of applying that structure in an introductory physics laboratory course. Students in an experimental condition were repeatedly instructed to make and act on quantitative comparisons between datasets, and between data and models, an approach that is common to all science disciplines. These instructions were slowly faded across the course. After the instructions had been removed, students in the experimental condition were 12 times more likely to spontaneously propose or make changes to improve their experimental methods than a control group, who performed traditional experimental activities. The students in the experimental condition were also four times more likely to identify and explain a limitation of a physical model using their data. Students in the experimental condition also showed much more sophisticated reasoning about their data. These differences between the groups were seen to persist into a subsequent course taken the following year.

  17. Lung Ultrasound in the Critically Ill Neonate

    PubMed Central

    Lichtenstein, Daniel A; Mauriat, Philippe

    2012-01-01

    Critical ultrasound is a new tool for first-line physicians, including neonate intensivists. The consideration of the lung as one major target allows to redefine the priorities. Simple machines work better than up-to-date ones. We use a microconvex probe. Ten standardized signs allow a majority of uses: the bat sign (pleural line), lung sliding and the A-line (normal lung surface), the quad sign and sinusoid sign indicating pleural effusion regardless its echogenicity, the tissue-like sign and fractal sign indicating lung consolidation, the B-line artifact and lung rockets (indicating interstitial syndrome), abolished lung sliding with the stratosphere sign, suggesting pneumothorax, and the lung point, indicating pneumothorax. Other signs are used for more sophisticated applications (distinguishing atelectasis from pneumonia for instance...). All these disorders were assessed in the adult using CT as gold standard with sensitivity and specificity ranging from 90 to 100%, allowing to consider ultrasound as a reasonable bedside gold standard in the critically ill. The same signs are found, with no difference in the critically ill neonate. Fast protocols such as the BLUE-protocol are available, allowing immediate diagnosis of acute respiratory failure using seven standardized profiles. Pulmonary edema e.g. yields anterior lung rockets associated with lung sliding, making the B-profile. The FALLS-protocol, inserted in a Limited Investigation including a simple model of heart and vessels, assesses acute circulatory failure using lung artifacts. Interventional ultrasound (mainly, thoracocenthesis) provides maximal safety. Referrals to CT can be postponed. CEURF proposes personnalized bedside trainings since 1990. Lung ultrasound opens physicians to a visual medicine. PMID:23255876

  18. Lung Ultrasound in the Critically Ill Neonate.

    PubMed

    Lichtenstein, Daniel A; Mauriat, Philippe

    2012-08-01

    Critical ultrasound is a new tool for first-line physicians, including neonate intensivists. The consideration of the lung as one major target allows to redefine the priorities. Simple machines work better than up-to-date ones. We use a microconvex probe. Ten standardized signs allow a majority of uses: the bat sign (pleural line), lung sliding and the A-line (normal lung surface), the quad sign and sinusoid sign indicating pleural effusion regardless its echogenicity, the tissue-like sign and fractal sign indicating lung consolidation, the B-line artifact and lung rockets (indicating interstitial syndrome), abolished lung sliding with the stratosphere sign, suggesting pneumothorax, and the lung point, indicating pneumothorax. Other signs are used for more sophisticated applications (distinguishing atelectasis from pneumonia for instance...). All these disorders were assessed in the adult using CT as gold standard with sensitivity and specificity ranging from 90 to 100%, allowing to consider ultrasound as a reasonable bedside gold standard in the critically ill. The same signs are found, with no difference in the critically ill neonate. Fast protocols such as the BLUE-protocol are available, allowing immediate diagnosis of acute respiratory failure using seven standardized profiles. Pulmonary edema e.g. yields anterior lung rockets associated with lung sliding, making the B-profile. The FALLS-protocol, inserted in a Limited Investigation including a simple model of heart and vessels, assesses acute circulatory failure using lung artifacts. Interventional ultrasound (mainly, thoracocenthesis) provides maximal safety. Referrals to CT can be postponed. CEURF proposes personnalized bedside trainings since 1990. Lung ultrasound opens physicians to a visual medicine. PMID:23255876

  19. Critical Psychologies for Critical Health Literacies

    ERIC Educational Resources Information Center

    Corcoran, Tim

    2014-01-01

    Health education is largely informed by psychological theories and practices that pursue reductionist views of people learning. However, critical attention is moving to understand health in ways that reconsider relationships to context and the forms of life within which everyday living takes place. This shift is apparent in theoretical…

  20. Criticality Model Report

    SciTech Connect

    J.M. Scaglione

    2003-03-12

    The purpose of the ''Criticality Model Report'' is to validate the MCNP (CRWMS M&O 1998h) code's ability to accurately predict the effective neutron multiplication factor (k{sub eff}) for a range of conditions spanned by various critical configurations representative of the potential configurations commercial reactor assemblies stored in a waste package may take. Results of this work are an indication of the accuracy of MCNP for calculating eigenvalues, which will be used as input for criticality analyses for spent nuclear fuel (SNF) storage at the proposed Monitored Geologic Repository. The scope of this report is to document the development and validation of the criticality model. The scope of the criticality model is only applicable to commercial pressurized water reactor fuel. Valid ranges are established as part of the validation of the criticality model. This model activity follows the description in BSC (2002a).

  1. Vulnerability of critical infrastructures : identifying critical nodes.

    SciTech Connect

    Cox, Roger Gary; Robinson, David Gerald

    2004-06-01

    The objective of this research was the development of tools and techniques for the identification of critical nodes within critical infrastructures. These are nodes that, if disrupted through natural events or terrorist action, would cause the most widespread, immediate damage. This research focuses on one particular element of the national infrastructure: the bulk power system. Through the identification of critical elements and the quantification of the consequences of their failure, site-specific vulnerability analyses can be focused at those locations where additional security measures could be effectively implemented. In particular, with appropriate sizing and placement within the grid, distributed generation in the form of regional power parks may reduce or even prevent the impact of widespread network power outages. Even without additional security measures, increased awareness of sensitive power grid locations can provide a basis for more effective national, state and local emergency planning. A number of methods for identifying critical nodes were investigated: small-world (or network theory), polyhedral dynamics, and an artificial intelligence-based search method - particle swarm optimization. PSO was found to be the only viable approach and was applied to a variety of industry accepted test networks to validate the ability of the approach to identify sets of critical nodes. The approach was coded in a software package called Buzzard and integrated with a traditional power flow code. A number of industry accepted test networks were employed to validate the approach. The techniques (and software) are not unique to power grid network, but could be applied to a variety of complex, interacting infrastructures.

  2. Transthoracic echocardiography in obstetric anaesthesia and obstetric critical illness.

    PubMed

    Dennis, A T

    2011-04-01

    Transthoracic echocardiography (TTE) is a powerful non-invasive diagnostic, monitoring and measurement device in medicine. In addition to cardiologists, many other specialised groups, including emergency and critical care physicians and cardiac anaesthetists, have recognised its ability to provide high quality information and utilise TTE in the care of their patients. In obstetric anaesthesia and management of obstetric critical illness, the favourable characteristics of pregnant women facilitate TTE examination. These include anterior and left lateral displacement of the heart, frequent employment of the left lateral tilted position to avoid aortocaval compression, spontaneous ventilation and wide acceptance of ultrasound technology by women. Of relevance to obstetric anaesthetists is that maternal morbidity and mortality due to cardiovascular disease is significant worldwide. This makes TTE an appropriate, important and applicable device in pregnant women. Clinician-performed TTE enables differentiation between the life-threatening causes of hypotension. In the critically ill woman this improves diagnostic accuracy and allows treatment interventions to be instituted and monitored at the point of patient care. This article outlines the application of TTE in the specialty of obstetric anaesthesia and in the management of obstetric critical illness. It describes the importance of TTE education, quality assurance and outcome recording. It also discusses how barriers to the routine implementation of TTE in obstetric anaesthesia and management of obstetric critical illness can be overcome. PMID:21315578

  3. Sarcopenia and critical illness: a deadly combination in the elderly.

    PubMed

    Hanna, Joseph S

    2015-03-01

    Sarcopenia is the age-associated loss of lean skeletal muscle mass. It is the result of multiple physiologic derangements, ultimately resulting in an insidious functional decline. Frailty, the clinical manifestation of sarcopenia and physical infirmity, is associated with significant morbidity and mortality in the elderly population. The underlying pathology results in a disruption of the individual's ability to tolerate internal and external stressors such as injury or illness. This infirmity results in a markedly increased risk of falls and subsequent morbidity and mortality from the resulting traumatic injury, as well as an inability to recover from medical insults, resulting in critical illness. The increasing prevalence of sarcopenia and critical illness in the elderly has resulted in a deadly intersection of disease processes. The lethality of this combination appears to be the result of altered muscle metabolism, decreased mitochondrial energetics needed to survive critical illness, and a chronically activated catabolic state likely mediated by tumor necrosis factor-α. Furthermore, these underlying derangements are independently associated with an increased incidence of critical illness, resulting in a progressive downward spiral. Considerable evidence has been gathered supporting the role of aggressive nutrition support and physical therapy in improving outcomes. Critical care practitioners must consider sarcopenia and the resulting frailty phenotype a comorbid condition so that the targeted interventions can be instituted and research efforts focused.

  4. Critical Literacy for Xenophobia: A Wake-Up Call

    ERIC Educational Resources Information Center

    Stevens, Lisa Patel; Stovall, David Omotoso

    2010-01-01

    Critical literacy has been on the map of literacy pedagogy internationally since the time of Freire, and more commonplace in the United States in the last few decades. However, in this column the authors argue that the common practices of critical literacy are insufficient for critical engagement with texts. The tools of critical literacy are…

  5. Critical Viscosity of Xenon

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. Because xenon near the critical point will collapse under its own weight, experiments on Earth (green line) are limited as they get closer (toward the left) to the critical point. CVX in the microgravity of space (red line) moved into unmeasured territory that scientists had not been able to reach.

  6. Critical Reflections: Making Sense of Career

    ERIC Educational Resources Information Center

    Dyer, Suzette

    2006-01-01

    In this article the five career narratives of three siblings and two unemployed men are drawn upon to critically examine the use of contemporary career discourse as a means to negotiate changes to work since the 1980s and to the present time. A critical analysis enables contemporary career discourse and workplace change to be located within the…

  7. The Intellectual Landscape of Critical Policy Analysis

    ERIC Educational Resources Information Center

    Diem, Sarah; Young, Michelle D.; Welton, Anjalé D.; Mansfield, Katherine Cumings; Lee, Pei-Ling

    2014-01-01

    What counts as critical policy analysis in education? Over the past 30 years, a tightening of national educational policies can be seen in the USA and across the globe. Over this same period of time, a growing number of educational policy scholars, dissatisfied with traditional frameworks, have used critical frameworks in their analyses. Their…

  8. Cohort: critical science

    NASA Astrophysics Data System (ADS)

    Digney, Bruce L.

    2007-04-01

    Unmanned vehicle systems is an attractive technology for the military, but whose promises have remained largely undelivered. There currently exist fielded remote controlled UGVs and high altitude UAV whose benefits are based on standoff in low complexity environments with sufficiently low control reaction time requirements to allow for teleoperation. While effective within there limited operational niche such systems do not meet with the vision of future military UxV scenarios. Such scenarios envision unmanned vehicles operating effectively in complex environments and situations with high levels of independence and effective coordination with other machines and humans pursing high level, changing and sometimes conflicting goals. While these aims are clearly ambitious they do provide necessary targets and inspiration with hopes of fielding near term useful semi-autonomous unmanned systems. Autonomy involves many fields of research including machine vision, artificial intelligence, control theory, machine learning and distributed systems all of which are intertwined and have goals of creating more versatile broadly applicable algorithms. Cohort is a major Applied Research Program (ARP) led by Defence R&D Canada (DRDC) Suffield and its aim is to develop coordinated teams of unmanned vehicles (UxVs) for urban environments. This paper will discuss the critical science being addressed by DRDC developing semi-autonomous systems.

  9. Criticality in the brain

    NASA Astrophysics Data System (ADS)

    de Arcangelis, L.; Lombardi, F.; Herrmann, H. J.

    2014-03-01

    Spontaneous brain activity has been recently characterized by avalanche dynamics with critical features for systems in vitro and in vivo. In this contribution we present a review of experimental results on neuronal avalanches in cortex slices, together with numerical results from a neuronal model implementing several physiological properties of living neurons. Numerical data reproduce experimental results for avalanche statistics. The temporal organization of avalanches can be characterized by the distribution of waiting times between successive avalanches. Experimental measurements exhibit a non-monotonic behaviour, not usually found in other natural processes. Numerical simulations provide evidence that this behaviour is a consequence of the alternation between states of high and low activity, leading to a balance between excitation and inhibition controlled by a single parameter. During these periods both the single neuron state and the network excitability level, keeping memory of past activity, are tuned by homoeostatic mechanisms. Interestingly, the same homoeostatic balance is detected for neuronal activity at the scale of the whole brain. We finally review the learning abilities of this neuronal network. Learning occurs via plastic adaptation of synaptic strengths by a non-uniform negative feedback mechanism. The system is able to learn all the tested rules and the learning dynamics exhibits universal features as a function of the strength of plastic adaptation. Any rule could be learned provided that the plastic adaptation is sufficiently slow.

  10. Extending the application of critical path methods.

    PubMed

    Coffey, R J; Othman, J E; Walters, J I

    1995-01-01

    Most health care organizations are using critical pathways in an attempt to reduce the variation in patient care, improve quality, enhance communication, and reduce costs. Virtually all of the critical path efforts to date have developed tables of treatments, medications, and so forth by day and have displayed them in a format known as a Gantt chart. This article presents a methodology for identifying the true "time-limiting" critical path, describes three additional methods for presenting the information--the network, precedent, and resource formats--and shows how these can significantly enhance current critical path efforts.

  11. The Need for Critics.

    ERIC Educational Resources Information Center

    Purves, Alan C.

    1994-01-01

    Responds to an article in the same issue of this journal about educational criticism as a form of qualitative inquiry. Argues that research in education has become a dead end. Agrees in the main with the article, but finds its view of criticism somewhat limited. Discusses the classroom itself as hypertext. (SR)

  12. Critical Thinking in Math.

    ERIC Educational Resources Information Center

    Ronis, Diane

    This booklet includes a wheel of problem solving strategies and a seven-step process for approaching and solving complicated problems. The information provided gives students a variety of ways to approach, analyze, and think critically about mathematics problems. The chapters present guides to promoting critical thinking in cooperative groups…

  13. Critical Literacy: Foundational Notes

    ERIC Educational Resources Information Center

    Luke, Allan

    2012-01-01

    The term "critical literacy" refers to use of the technologies of print and other media of communication to analyze, critique, and transform the norms, rule systems, and practices governing the social fields of everyday life (A. Luke, 2004). Since Freire's (1970) educational projects in Brazil, approaches to critical literacy have been developed…

  14. Against Critical Thinking Pedagogy

    ERIC Educational Resources Information Center

    Hayes, David

    2015-01-01

    Critical thinking pedagogy is misguided. Ostensibly a cure for narrowness of thought, by using the emotions appropriate to conflict, it names only one mode of relation to material among many others. Ostensibly a cure for fallacies, critical thinking tends to dishonesty in practice because it habitually leaps to premature ideas of what the object…

  15. Rethinking Critical Thinking

    ERIC Educational Resources Information Center

    Downs, Christopher J.

    2008-01-01

    Critical thinking is of primary importance in higher education, yet the concept remains slippery and the skill elusive. The author argues that most current critical thinking textbooks are out of line with the seminal work of John Dewey. Rather than logical argument and justification, it is suggested that carefulness, open-mindedness and creativity…

  16. Critical Teaching and Learning.

    ERIC Educational Resources Information Center

    Young, R. E.

    1988-01-01

    This essay begins with a description of Jurgen Habermas's theory of communicative action, emphasizing aspects which relate to a critical theory of teaching/learning. Existing theory and research is reviewed. A critical theory of pedagogy as a form of communicative action or interaction is presented. (MT)

  17. Critical Education Studies

    ERIC Educational Resources Information Center

    Boxley, Simon

    2015-01-01

    Education Studies as an academic discipline within HE in the UK is a contested area. One thing most Education Studies programmes might agree on is that they are "critical". But what is a genuinely critical Education Studies degree? And, how could such a programme survive within the hostile neoliberal environment of the contemporary UK?…

  18. Critical Social Numeracy.

    ERIC Educational Resources Information Center

    Lake, David

    2002-01-01

    Presents a five-step method to develop the critical numeracy knowledge of numerically intimidated students. Examines the method in detail, discussing Piagetian diagnostic tools and how to adapt the Structure of the Observed Learning Outcome (SOLO) taxonomy to teach critical numeracy. (CMK)

  19. CRITICAL LOADS METHODS

    EPA Science Inventory

    I summarize the results of an interagency project that 1) defines a generic approach to quantifying and reporting critical loads, and 2) exercises that generic approach by examining a data rich system -- the critical loads of sulfur deposition and it's effect on the chronic acidi...

  20. Creating a Critical Thinker

    ERIC Educational Resources Information Center

    Piergiovanni, Polly R.

    2014-01-01

    A college education is expected to improve students' critical thinking skills. Keeping students active in class--through writing activities and class discussion--has been shown to help students think critically. In this article, creative hands-on activities, which are common in engineering courses, are shown to improve students' critical…

  1. PRECLOSURE CRITICALITY ANALYSIS PROCESS REPORT

    SciTech Connect

    A.E. Danise

    2004-10-25

    This report describes a process for performing preclosure criticality analyses for a repository at Yucca Mountain, Nevada. These analyses will be performed from the time of receipt of fissile material until permanent closure of the repository (preclosure period). The process describes how criticality safety analyses will be performed for various configurations of waste in or out of waste packages that could occur during preclosure as a result of normal operations or event sequences. The criticality safety analysis considers those event sequences resulting in unanticipated moderation, loss of neutron absorber, geometric changes, or administrative errors in waste form placement (loading) of the waste package. The report proposes a criticality analyses process for preclosure to allow a consistent transition from preclosure to postclosure, thereby possibly reducing potential cost increases and delays in licensing of Yucca Mountain. The proposed approach provides the advantage of using a parallel regulatory framework for evaluation of preclosure and postclosure performance and is consistent with the U.S. Nuclear Regulatory Commission's approach of supporting risk-informed, performance-based regulation for fuel cycle facilities, ''Yucca Mountain Review Plan, Final Report'', and 10 CFR Part 63. The criticality-related criteria for ensuring subcriticality are also described as well as which guidance documents will be utilized. Preclosure operations and facilities have significant similarities to existing facilities and operations currently regulated by the U.S. Nuclear Regulatory Commission; therefore, the design approach for preclosure criticality safety will be dictated by existing regulatory requirements while using a risk-informed approach with burnup credit for in-package operations.

  2. Critical Schwinger Pair Production.

    PubMed

    Gies, Holger; Torgrimsson, Greger

    2016-03-01

    We investigate Schwinger pair production in spatially inhomogeneous electric backgrounds. A critical point for the onset of pair production can be approached by fields that marginally provide sufficient electrostatic energy for an off-shell long-range electron-positron fluctuation to become a real pair. Close to this critical point, we observe features of universality which are analogous to continuous phase transitions in critical phenomena with the pair-production rate serving as an order parameter: electric backgrounds can be subdivided into universality classes and the onset of pair production exhibits characteristic scaling laws. An appropriate design of the electric background field can interpolate between power-law scaling, essential Berezinskii-Kosterlitz-Thouless-type scaling, and a power-law scaling with log corrections. The corresponding critical exponents only depend on the large-scale features of the electric background, whereas the microscopic details of the background play the role of irrelevant perturbations not affecting criticality. PMID:26991162

  3. Telemedicine in Critical Care

    PubMed Central

    Murias, Gastón; Sales, Bernat; Garcia-Esquirol, Oscar; Blanch, Lluis

    2009-01-01

    Critical care medicine is the specialty that cares for patients with acute life-threatening illnesses where intensivists look after all aspects of patient care. Nevertheless, shortage of physicians and nurses, the relationship between high costs and economic restrictions, and the fact that critical care knowledge is only available at big hospitals puts the system on the edge. In this scenario, telemedicine might provide solutions to improve availability of critical care knowledge where the patient is located, improve relationship between attendants in different institutions and education material for future specialist training. Current information technologies and networking capabilities should be exploited to improve intensivist coverage, advanced alarm systems and to have large critical care databases of critical care signals. PMID:19452034

  4. Higher Education: A Critical Business.

    ERIC Educational Resources Information Center

    Barnett, Ronald

    Current concepts of critical thinking need to be reconstrued into the much broader concept of "critical being" and applied to higher education. Under this construct, critical persons (students) become more than just critical thinkers; they engage critically with the world and with themselves; they not only reflect critically on knowledge, but also…

  5. Critical points of metal vapors

    SciTech Connect

    Khomkin, A. L. Shumikhin, A. S.

    2015-09-15

    A new method is proposed for calculating the parameters of critical points and binodals for the vapor–liquid (insulator–metal) phase transition in vapors of metals with multielectron valence shells. The method is based on a model developed earlier for the vapors of alkali metals, atomic hydrogen, and exciton gas, proceeding from the assumption that the cohesion determining the basic characteristics of metals under normal conditions is also responsible for their properties in the vicinity of the critical point. It is proposed to calculate the cohesion of multielectron atoms using well-known scaling relations for the binding energy, which are constructed for most metals in the periodic table by processing the results of many numerical calculations. The adopted model allows the parameters of critical points and binodals for the vapor–liquid phase transition in metal vapors to be calculated using published data on the properties of metals under normal conditions. The parameters of critical points have been calculated for a large number of metals and show satisfactory agreement with experimental data for alkali metals and with available estimates for all other metals. Binodals of metals have been calculated for the first time.

  6. Criticality assessment of LLRWDF closure

    SciTech Connect

    Sarrack, A.G.; Weber, J.H.; Woody, N.D.

    1992-10-06

    During the operation of the Low Level Radioactive Waste Disposal Facility (LLRWDF), large amounts (greater than 100 kg) of enriched uranium (EU) were buried. This EU came primarily from the closing and decontamination of the Naval Fuels Facility in the time period from 1987--1989. Waste Management Operations (WMO) procedures were used to keep the EU boxes separated to prevent possible criticality during normal operation. Closure of the LLRWDF is currently being planned, and waste stabilization by Dynamic Compaction (DC) is proposed. Dynamic compaction will crush the containers in the LLRWDF and result in changes in their geometry. Research of the LLRWDF operations and record keeping practices have shown that the EU contents of trenches are known, but details of the arrangement of the contents cannot be proven. Reviews of the trench contents, combined with analysis of potential critical configurations, revealed that some portions of the LLRWDF can be expected to be free of criticality concerns while other sections have credible probabilities for the assembly of a critical mass, even in the uncompacted configuration. This will have an impact on the closure options and which trenches can be compacted.

  7. A holographic critical point

    SciTech Connect

    DeWolfe, Oliver; Rosen, Christopher; Gubser, Steven S.

    2011-04-15

    We numerically construct a family of five-dimensional black holes exhibiting a line of first-order phase transitions terminating at a critical point at finite chemical potential and temperature. These black holes are constructed so that the equation of state and baryon susceptibilities approximately match QCD lattice data at vanishing chemical potential. The critical end point in the particular model we consider has temperature 143 MeV and chemical potential 783 MeV. Critical exponents are calculated, with results that are consistent with mean-field scaling relations.

  8. Critical-point nuclei

    SciTech Connect

    Clark, R.M.

    2004-10-01

    It has been suggested that a change of nuclear shape may be described in terms of a phase transition and that specific nuclei may lie close to the critical point of the transition. Analytical descriptions of such critical-point nuclei have been introduced recently and they are described briefly. The results of extensive searches for possible examples of critical-point behavior are presented. Alternative pictures, such as describing bands in the candidate nuclei using simple {Delta}K = 0 and {Delta}K = 2 rotational-coupling models, are discussed, and the limitations of the different approaches highlighted. A possible critical-point description of the transition from a vibrational to rotational pairing phase is suggested.

  9. The Critical Thinking Workout.

    ERIC Educational Resources Information Center

    Masters, Terry McDaniel

    1991-01-01

    Presents a critical thinking exercise program, modeled on a physical exercise workout, for elementary teachers to use in the classroom. It includes warm-up exercises, a more strenuous workout, and a cool-down period for the brain. (SM)

  10. Critical Access Hospitals (CAH)

    MedlinePlus

    ... CAH Conditions of Participation . What are the location requirements for CAH status? Critical Access Hospitals must be ... clinic that does not meet the CAH distance requirements? As of January 1, 2008, all CAHs, including ...

  11. Quantum Critical Elasticity.

    PubMed

    Zacharias, Mario; Paul, Indranil; Garst, Markus

    2015-07-10

    We discuss elastic instabilities of the atomic crystal lattice at zero temperature. Because of long-range shear forces of the solid, at such transitions the phonon velocities vanish, if at all, only along certain crystallographic directions, and, consequently, the critical phonon fluctuations are suppressed to a lower dimensional manifold and governed by a Gaussian fixed point. In the case of symmetry-breaking elastic transitions, a characteristic critical phonon thermodynamics arises that is found, e.g., to violate Debye's T(3) law for the specific heat. We point out that quantum critical elasticity is triggered whenever a critical soft mode couples linearly to the strain tensor. In particular, this is relevant for the electronic Ising-nematic quantum phase transition in a tetragonal crystal as discussed in the context of certain cuprates, ruthenates, and iron-based superconductors. PMID:26207483

  12. About Critical Care Nursing

    MedlinePlus

    ... Join Now Our Community Value of Belonging Member Benefits and Savings Awards Certification Apply Online Renew Your ... and traveling critical care nurses to fill staffing gaps in every part of the U.S. These requests ...

  13. Critical Viscosity of Xenon

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. Shear thirning will cause a normally viscous fluid -- such as pie filling or whipped cream -- to deform and flow more readily under high shear conditions. In shear thinning, a pocket of fluid will deform and move one edge forward, as depicted here.

  14. Critical experiment data archiving

    SciTech Connect

    Koponen, B.L. ); Clayton, E.D.; Doherty, A.L. )

    1991-01-01

    Critical experiment facilities produced a large number of important data during the past 45 years; however, many useful data remain unpublished. The unpublished material exists in the form of experimenters' logbooks, notes, photographs, material descriptions, etc., This data could be important for computer code validation, understanding the physics of criticality, facility design, or for setting process limits. In the past, criticality specialists have been able to obtain unpublished details by direct contact with the experimenters. Obviously, this will not be possible indefinitely. Most of the US critical experiment facilities are now closed, and the experimenters are moving to other jobs, retiring, or otherwise becoming unavailable for this informal assistance. Also, the records are in danger of being discarded or lost during facility closures, cleanup activities, or in storage. A project was begun in 1989 to ensure that important unpublished data from critical experiment facilities in the United States are archived and made available as a resource of the US Department of Energy's (DOE's) Nuclear Criticality Information System (NCIS). The objective of this paper is to summarize the project accomplishments to date and bring these activities to the attention of those who might be aware of the location of source information needed for archiving and could assist in getting the materials included in the archive.

  15. [Nutrition in the critically ill].

    PubMed

    Weimann, A; Andrä, J; Sablotzki, A

    2011-11-01

    The prognostic impact of inadequate energy and protein supply in malnourished intensive care patients has been recently reemphasized. Consent exists about the beneficial effects of early enteral nutrition in the critically ill. However, gastrointestinal intolerance of the critically ill may be a major problem for the feasibility of enteral nutrition bearing additional risks. In case adequate enteral nutrition cannot be realized, there is controversy about the appropriate time to start total parenteral or combined enteral / parenteral nutrition. Due to potential adverse effects immune-enhancing substrates have to be cautiously administered. For standardization implementation of a guideline based nutritional protocol is recommended. The review refers to the recent guidelines of the European Society for Clinical Nutrition and Metabolism (2009), the American Society for Parenteral and Enteral Nutrition (ASPEN) (2009) and the German Sepsis Society (DSG) (2010).

  16. Degenerate and critical Bloch branes

    SciTech Connect

    Souza Dutra, A. de; Amaro de Faria, A. C. Jr.; Hott, M.

    2008-08-15

    In the last few years a number of works reported the appearance of thick branes with internal structure, induced by the parameter which controls the interaction between two scalar fields coupled to gravity in (4,1) dimensions in warped space-time with one extra dimension. Here we show that one can implement the control over the brane thickness without needing to change the potential parameter. On the contrary, this is going to be done by means of the variation of a parameter associated with the domain wall degeneracy. We also report the existence of novel and qualitatively different solutions for a critical value of the degeneracy parameter, which could be called critical Bloch branes.

  17. Mapping Self-Organized Criticality onto Criticality

    NASA Astrophysics Data System (ADS)

    Sornette, Didier; Johansen, Anders; Dornic, Ivan

    1995-03-01

    We present a general conceptual framework for self-organized criticality (SOC), based on the recognition that it is nothing but the expression, “unfolded" in a suitable parameter space, of an underlying unstable dynamical critical point. More precisely, SOC is shown to result from the tunning of the order parameter to a vanishingly small, but positive value, thus ensuring that the corresponding control parameter lies exactly at its critical value for the underlying transition. This clarifies the role and nature of the very slow driving rate common to all systems exhibiting SOC. This mechanism is shown to apply to models of sandpiles, earthquakes, depinning, fractal growth and forest fires, which have been proposed as examples of SOC. Nous proposons une stratégie générale pour identifier le mécanisme responsable des phénomènes critiques auto-organisés, basée, sur l'idée qu'ils sont simplement la traduction, dans un espace de paramètres choisis, d'un point critique dynamique instable standard. La criticalité auto-organisée résulte du contrôle du paramètre d'ordre ajusté à une valeur positive tendant vers zéro, ce qui assure automatiquement que le paramètre de contrôle correspondant se cale exactement sur sa valeur critique de la transition de critique sous-jacente. Ce résultat explique le rôle particulier joué par le forçage infiniment lent qui est un caractère commun à tous les systèmes critiques auto-organisés. Nous appliquons ces idées aux modèles de tas de sable, aux modèles de tremblements de terre, de feux de forêts, aux transitions de décrochage et aux modèles de croissance fractale, qui ont été proposés comme autant d'exemples caractéristiques de la criticalité auto-organisée.

  18. From Self-Organized to Extended Criticality

    PubMed Central

    Lovecchio, Elisa; Allegrini, Paolo; Geneston, Elvis; West, Bruce J.; Grigolini, Paolo

    2012-01-01

    We address the issue of criticality that is attracting the attention of an increasing number of neurophysiologists. Our main purpose is to establish the specific nature of some dynamical processes that although physically different, are usually termed as “critical,” and we focus on those characterized by the cooperative interaction of many units. We notice that the term “criticality” has been adopted to denote both noise-induced phase transitions and Self-Organized Criticality (SOC) with no clear connection with the traditional phase transitions, namely the transformation of a thermodynamic system from one state of matter to another. We notice the recent attractive proposal of extended criticality advocated by Bailly and Longo, which is realized through a wide set of critical points rather than emerging as a singularity from a unique value of the control parameter. We study a set of cooperatively firing neurons and we show that for an extended set of interaction couplings the system exhibits a form of temporal complexity similar to that emerging at criticality from ordinary phase transitions. This extended criticality regime is characterized by three main properties: (i) In the ideal limiting case of infinitely large time period, temporal complexity corresponds to Mittag-Leffler complexity; (ii) For large values of the interaction coupling the periodic nature of the process becomes predominant while maintaining to some extent, in the intermediate time asymptotic region, the signature of complexity; (iii) Focusing our attention on firing neuron avalanches, we find two of the popular SOC properties, namely the power indexes 2 and 1.5 respectively for time length and for the intensity of the avalanches. We derive the main conclusion that SOC emerges from extended criticality, thereby explaining the experimental observation of Plenz and Beggs: avalanches occur in time with surprisingly regularity, in apparent conflict with the temporal complexity of physical

  19. Prediction of critical grout parameters: critical flow rate

    SciTech Connect

    Tallent, O.K.; McDaniel, E.W.; Godsey, T.T.; Dodson, K.E.

    1986-01-01

    Waste disposal is rapidly becoming one of the most important technological endeavors of our time and fixation of waste in cement-based materials is an important part of the endeavor. Investigations of given wastes are usually individually conducted and reported. In this study, data obtained from investigation of critical flow rates for three distinctly different wastes are correlated with apparent viscosity data via a single empirical equation. Critical flow rate, which is an important variable in waste grout work, is defined as the flow rate at which a grout must be pumped through a reference pipe to obtain turbulent flow. It is important that the grout flow be turbulent since laminar flow allows caking on pipe walls and causes eventual plugging. The three wastes used in this study can be characterized as containing: (1) high nitrate, carbonate, and sulfate; (2) high phosphate; and (3) high fluoride, ammonium, and suspended solids waste. The measurements of apparent viscosity (grouts are non-Newtonian fluids) and other measurements to obtain data to calculate the critical flow rates were made using a Fann-Direct Reading Viscometer, Model 35A.

  20. Minimum Critical Values Study

    SciTech Connect

    Fox, P.B.

    2005-07-11

    This report provides minimum critical values for various 30-cm water-reflected uranium and plutonium oxide and nitrate aqueous mixtures as calculated by the SCALE CSAS1X sequence using the 238-group ENDF/B-V neutron cross-section library. The minimum values were determined through parametric searches in one-dimensional geometry. The calculations have been performed to obtain the minimum values: critical volume and mass for spheres, critical radius for cylinders, critical thickness for slabs, and minimum critical concentration (infinite geometry) for the following homogeneous mixtures: (1) UO{sub 2}-H{sub 2}O for 3, 4, 5, 20, and 100 wt % {sup 235}U; (2) UNH for 3, 4, 5, 20, and 100 wt % {sup 235}U; (3) PuO{sub 2}-H{sub 2}O for 100/0/0, 95/5/0, 90/5/5, 80/10/10, and 71/17/11/1 wt % of {sup 239}Pu/{sup 240}Pu/{sup 241}Pu(/{sup 242}Pu); and (4) PuNH for 100/0/0, 95/5/0, 90/5/5, 80/10/10, and 71/17/11/1 wt % of {sup 239}Pu/{sup 240}Pu/{sup 241}Pu(/{sup 242}Pu). All bounding surfaces were fully reflected by 30 cm of H{sub 2}O.

  1. Predictability of critical transitions

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaozhu; Kuehn, Christian; Hallerberg, Sarah

    2015-11-01

    Critical transitions in multistable systems have been discussed as models for a variety of phenomena ranging from the extinctions of species to socioeconomic changes and climate transitions between ice ages and warm ages. From bifurcation theory we can expect certain critical transitions to be preceded by a decreased recovery from external perturbations. The consequences of this critical slowing down have been observed as an increase in variance and autocorrelation prior to the transition. However, especially in the presence of noise, it is not clear whether these changes in observation variables are statistically relevant such that they could be used as indicators for critical transitions. In this contribution we investigate the predictability of critical transitions in conceptual models. We study the quadratic integrate-and-fire model and the van der Pol model under the influence of external noise. We focus especially on the statistical analysis of the success of predictions and the overall predictability of the system. The performance of different indicator variables turns out to be dependent on the specific model under study and the conditions of accessing it. Furthermore, we study the influence of the magnitude of transitions on the predictive performance.

  2. Criticality in Plasma Membranes

    NASA Astrophysics Data System (ADS)

    Machta, Benjamin; Papanikolaou, Stefanos; Sethna, James; Veatch, Sarah

    2011-03-01

    We are motivated by recent observations of micron-sized critical fluctuations in the 2d Ising Universality class in plasma membrane vesicles that are isolated from cortical cytoskeleton. We construct a minimal model of the plasma membrane's interaction with intact cytoskeleton which explains why large scale phase separation has not been observed in Vivo. In addition, we use analytical techniques from conformal field theory and numerical simulations to investigate the form of effective forces mediated by the membrane's proximity to criticality. We show that the range of this force is maximized near a critical point and we quantify its usefulness in mediating communication using techniques from information theory. Finally we use theoretical techniques from statistical physics in conjunction with Monte-Carlo simulations to understand how criticality can be used to increase the efficiency of membrane bound receptor mediated signaling. We expect that this sort of analysis will be broadly useful in understanding and quantifying the role of lipid ``rafts'' in a wide variety of membrane bound processes. Generally, we demonstrate that critical fluctuations provide a physical mechanism to organize and spatially segregate membrane components by providing channels for interaction over relatively large distances.

  3. Self-organized criticality

    SciTech Connect

    Per Bak ); Kan Chen )

    1991-01-01

    Just as the proverbial straw broke the camel's back, catastrophes, from earthquakes and avalanches to a stock market crash, can be triggered by a minor event. The authors argue that complex systems naturally evolve to a critical state. Their theory already has improved understanding of motion in the earth's crust, economies and ecosystems. The theory of self-organized criticality states that many composite systems naturally evolve to a critical state in which a minor event starts a chain reaction that can affect any number of elements in the system. Although composite systems produce more minor events than catastrophes, chain reactions of all sizes are an integral part of the dynamics. According to the theory, the mechanism that leads to minor events is the same one that leads to major events. Furthermore, composite systems never reach equilibrium but instead evolve from one metastable state to the next. Self-organized criticality is a holistic theory: the global features, such as the relative number of large and small events, do not depend on the microscopic mechanisms. Consequently, global features of the system cannot be understood by analyzing the parts separately. To the authors' knowledge, self-organized criticality is the only model or mathematical description that has led to a holistic theory for dynamic systems.

  4. Critical Management in Knowledge Organizations

    ERIC Educational Resources Information Center

    Macpherson, Reynold

    2008-01-01

    Purpose: The purpose of this paper is to invite educational managers and management educators to reflect critically on practice. Design/methodology/approach: Using the point of Socrates' death, the paper suggests ways of reflecting on actions using ethically-critical, socially-critical, environmentally-critical, politically-critical and…

  5. Critical Thinking in Business Education.

    ERIC Educational Resources Information Center

    Sormunen, Carolee

    Critical thinking is currently a prominent issue in education. For business educators, four issues must be considered: the meaning of critical thinking, how critical thinking can be introduced into the curriculum, how critical thinking is developed in courses, and how critical thinking can be evaluated. The literature identifies three theoretical…

  6. The Anatomy of Critical Discourse.

    ERIC Educational Resources Information Center

    Rosenfield, Lawrence W.

    1968-01-01

    Critical discourse is best understood when its logical features are identified. An examination of the basic elements and modes of rhetorical criticism (a form of critical discourse) produces a finite set of options for the critic, thus enabling him to develop a system of alternatives in his critical efforts. For example, by selecting from among…

  7. Surface Hold Advisor Using Critical Sections

    NASA Technical Reports Server (NTRS)

    Law, Caleb Hoi Kei (Inventor); Hsiao, Thomas Kun-Lung (Inventor); Mittler, Nathan C. (Inventor); Couluris, George J. (Inventor)

    2013-01-01

    The Surface Hold Advisor Using Critical Sections is a system and method for providing hold advisories to surface controllers to prevent gridlock and resolve crossing and merging conflicts among vehicles traversing a vertex-edge graph representing a surface traffic network on an airport surface. The Advisor performs pair-wise comparisons of current position and projected path of each vehicle with other surface vehicles to detect conflicts, determine critical sections, and provide hold advisories to traffic controllers recommending vehicles stop at entry points to protected zones around identified critical sections. A critical section defines a segment of the vertex-edge graph where vehicles are in crossing or merging or opposite direction gridlock contention. The Advisor detects critical sections without reference to scheduled, projected or required times along assigned vehicle paths, and generates hold advisories to prevent conflicts without requiring network path direction-of-movement rules and without requiring rerouting, rescheduling or other network optimization solutions.

  8. Morphogenesis at criticality?

    NASA Astrophysics Data System (ADS)

    Krotov, Dmitry; Dubuis, Julien; Gregor, Thomas; Bialek, William

    2014-03-01

    Spatial patterns in the early fruit fly embryo emerge from a network of interactions among transcription factors, the gap genes, driven by maternal inputs. Such networks can exhibit many qualitatively different behaviors, separated by critical surfaces. At criticality, we should observe strong correlations in the fluctuations of different genes around their mean expression levels, a slowing of the dynamics along some but not all directions in the space of possible expression levels, correlations of expression fluctuations over long distances in the embryo, and departures from a Gaussian distribution of these fluctuations. Analysis of recent experiments on the gap genes shows that all these signatures are observed, and that the different signatures are related in ways predicted by theory. While there might be other explanations for these individual phenomena, the confluence of evidence suggests that this genetic network is tuned to criticality.

  9. Interface localization near criticality

    NASA Astrophysics Data System (ADS)

    Delfino, Gesualdo

    2016-05-01

    The theory of interface localization in near-critical planar systems at phase coexistence is formulated from first principles. We show that mutual delocalization of two interfaces, amounting to interfacial wetting, occurs when the bulk correlation length critical exponent ν is larger than or equal to 1. Interaction with a boundary or defect line involves an additional scale and a dependence of the localization strength on the distance from criticality. The implications are particularly rich in the boundary case, where delocalization proceeds through different renormalization patterns sharing the feature that the boundary field becomes irrelevant in the delocalized regime. The boundary delocalization (wetting) transition is shown to be continuous, with surface specific heat and layer thickness exponents which can take values that we determine.

  10. Linear response at criticality

    NASA Astrophysics Data System (ADS)

    Svenkeson, Adam; Bologna, Mauro; Grigolini, Paolo

    2012-10-01

    We study a set of cooperatively interacting units at criticality, and we prove with analytical and numerical arguments that they generate the same renewal non-Poisson intermittency as that produced by blinking quantum dots, thereby giving a stronger support to the results of earlier investigation. By analyzing how this out-of-equilibrium system responds to harmonic perturbations, we find that the response can be described only using a new form of linear response theory that accounts for aging and the nonergodic behavior of the underlying process. We connect the undamped response of the system at criticality to the decaying response predicted by the recently established nonergodic fluctuation-dissipation theorem for dichotomous processes using information about the second moment of the fluctuations. We demonstrate that over a wide range of perturbation frequencies the response of the cooperative system is greatest when at criticality.

  11. Morphogenesis at criticality

    PubMed Central

    Krotov, Dmitry; Dubuis, Julien O.; Gregor, Thomas; Bialek, William

    2014-01-01

    Spatial patterns in the early fruit fly embryo emerge from a network of interactions among transcription factors, the gap genes, driven by maternal inputs. Such networks can exhibit many qualitatively different behaviors, separated by critical surfaces. At criticality, we should observe strong correlations in the fluctuations of different genes around their mean expression levels, a slowing of the dynamics along some but not all directions in the space of possible expression levels, correlations of expression fluctuations over long distances in the embryo, and departures from a Gaussian distribution of these fluctuations. Analysis of recent experiments on the gap gene network shows that all these signatures are observed, and that the different signatures are related in ways predicted by theory. Although there might be other explanations for these individual phenomena, the confluence of evidence suggests that this genetic network is tuned to criticality. PMID:24516161

  12. Why Mission-Critical Systems Are Critical to the Future of Academic Libraries

    ERIC Educational Resources Information Center

    Oberlander, Cyril

    2012-01-01

    A mission-critical system is one that is so intertwined with the operation of an organization that the organization can scarcely function without it. Just as in corporations, mission-critical library systems offer the capability to unlock talent and time. They are essential to the transformation of higher education and the learning environment. A…

  13. Militarily Critical Technology Program

    NASA Astrophysics Data System (ADS)

    Doherty, J.; Wick, R.; Sellers, P.

    The Militarily Critical Technology Program (MCTP) creates two technology lists: Militarily Critical Technology List (MCTL), which is focused on protecting US technology, and Developing Science and Technology List (DSTL). There are 20 different technology areas; two in particular are discussed in this poster paper, Space Systems Technologies and Lasers & Optics Technologies. The authors are the Technology Working Group chairs for Space Systems (Jim Doherty) and Lasers & Optics (Ray Wick), both from Institute for Defense Analyses (IDA), and also IDAs task leader for the MCTP (Paul Sellers).

  14. Critical Viscosity of Xenon

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. The sample cell at the heart of CVX-2 will sit inside a thermostat providing three layers of insulation. The cell itself comprises a copper body that conducts heat efficiently and smoothes out thermal variations that that would destroy the xenon's uniformity. Inside the cell, the oscillating screen viscometer element is supported between two pairs of electrodes that deflect the screen and then measure screen motion.

  15. Critical Viscosity of Xenon

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2001 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. The thermostat for CVX sits inside the white cylinder on a support structure that is placed inside a pressure canister. A similar canister holds the electronics and control systems. The CVX-2 arrangement is identical. The principal investigator is Dr. Robert F. Berg (not shown) of the National Institutes of Standards and Technology, Gaithersburg, MD. This is a detail view of MSFC 0100143.

  16. Emergency responders' critical infrared (ERCI)

    NASA Astrophysics Data System (ADS)

    Konsin, Larry S.

    2004-08-01

    Emergency Responders (Fire, Police, Medical, and Emergency Management) face a high risk of injury or death. Even before September 11, 2001, public and private organizations have been driven to better protect Emergency Responders through education, training and improved technology. Recent research on Emergency Responder safety, health risks, and personal protective requirements, shows infrared (IR) imaging as a critical need. Today"s Emergency Responders are increasingly challenged to do more, facing demands requiring technological assistance and/or solutions. Since the introduction of Fire Service IR imaging in the mid 1990s, applications have increased. Emergency response IR is no longer just seeing through smoke to find victims or the seat of a fire. Many more mission critical needs now exist across the broad spectrum of emergency response. At the same time, Emergency Responder injuries and deaths are increasing. The Office of Domestic Preparedness (ODP) has also recognized IR imaging as critical in protecting our communities -- and in preventing many of the injuries and deaths of Emergency Responders. Currently, only 25% of all fire departments (or less than 7% of individual firefighters) have IR imaging. Availability to Police, EMS and Emergency Management is even lower. Without ERCI, Emergency Responders and our communities are at risk.

  17. Quantum criticality and black holes.

    PubMed

    Sachdev, Subir; Müller, Markus

    2009-04-22

    Many condensed matter experiments explore the finite temperature dynamics of systems near quantum critical points. Often, there are no well-defined quasiparticle excitations, and so quantum kinetic equations do not describe the transport properties completely. The theory shows that the transport coefficients are not proportional to a mean free scattering time (as is the case in the Boltzmann theory of quasiparticles), but are completely determined by the absolute temperature and by equilibrium thermodynamic observables. Recently, explicit solutions of this quantum critical dynamics have become possible via the anti-de Sitter/conformal field theory duality discovered in string theory. This shows that the quantum critical theory provides a holographic description of the quantum theory of black holes in a negatively curved anti-de Sitter space, and relates its transport coefficients to properties of the Hawking radiation from the black hole. We review how insights from this connection have led to new results for experimental systems: (i) the vicinity of the superfluid-insulator transition in the presence of an applied magnetic field, and its possible application to measurements of the Nernst effect in the cuprates, (ii) the magnetohydrodynamics of the plasma of Dirac electrons in graphene and the prediction of a hydrodynamic cyclotron resonance. PMID:21825396

  18. Three studies in quantum criticality

    NASA Astrophysics Data System (ADS)

    Ramazashvili, Revaz

    This thesis has been unified by the general topic of quantum criticality, an area of active current research which draws inspiration from the ongoing experiments on a host of T = 0 transitions of various nature, such as magnetic transitions, metal-insulator and superconductor-insulator transitions, Quantum Hall plateau-to-plateau transitions, and many others. In addition to the experimental motivation, the field is being driven by the internal demands of the theory, as many fundamental questions regarding e.g. the nature of the order parameter or the effects of disorder still remain to be answered. Chapter 1, the Introduction, briefly covers the key theoretical concepts and describes relevant materials. In Chapter 2 of the thesis, it is shown that, for a superconductor with a gap which is odd with respect to reflection in the Fermi surface, it is possible to suppress the transition temperature to zero without violating either the time reversal or the translational invariance. This feature is a qualitative hallmark of such superconductors, distinguishing them from isotropic BCS superconductors as well as from superconductors with anisotropic pairing. The pair propagator is calculated dose to this quantum critical point along with several observable quantities. It is argued that experimental studies of a superconducting quantum critical point in clean materials may provide a diagnostic tool for unusual mechanisms of superconductivity. Chapter 3 of the thesis concentrates on an s-wave superconductor near a quantum critical point driven by pairbreaking disorder. The disorder average of the pair propagator is calculated diagrammatically, and the low-temperature thermodynamic and transport properties are evaluated. It is argued that, in the absence of the effects of glassiness, this description should hold equally well for a strong-coupling superconductor at a quantum critical point. Chapter 4 presents a phenomenological theory of the quantum critical point observed in

  19. Communication and Critical Thinking Skills

    NASA Astrophysics Data System (ADS)

    Simmons, Elizabeth H.

    2011-03-01

    This talk will discuss how faculty can help graduate students (and even postdocs) improve non-technical professional skills required for success in scientific careers. Examples to be covered will include a) planning and delivering high-quality presentations b) listening critically to others' presentations c) writing grant proposals, cover letters, and CV's d) reviewing manuscripts and responding to referee reports. The faculty member(s) involved must be prepared to project a welcoming attitude, to convey the importance of these skills, and to make a consistent investment of time.

  20. Critical market crashes

    NASA Astrophysics Data System (ADS)

    Sornette, D.

    2003-04-01

    This review presents a general theory of financial crashes and of stock market instabilities that his co-workers and the author have developed over the past seven years. We start by discussing the limitation of standard analyses for characterizing how crashes are special. The study of the frequency distribution of drawdowns, or runs of successive losses shows that large financial crashes are “outliers”: they form a class of their own as can be seen from their statistical signatures. If large financial crashes are “outliers”, they are special and thus require a special explanation, a specific model, a theory of their own. In addition, their special properties may perhaps be used for their prediction. The main mechanisms leading to positive feedbacks, i.e., self-reinforcement, such as imitative behavior and herding between investors are reviewed with many references provided to the relevant literature outside the narrow confine of Physics. Positive feedbacks provide the fuel for the development of speculative bubbles, preparing the instability for a major crash. We demonstrate several detailed mathematical models of speculative bubbles and crashes. A first model posits that the crash hazard drives the market price. The crash hazard may sky-rocket at some times due to the collective behavior of “noise traders”, those who act on little information, even if they think they “know”. A second version inverses the logic and posits that prices drive the crash hazard. Prices may skyrocket at some times again due to the speculative or imitative behavior of investors. According the rational expectation model, this entails automatically a corresponding increase of the probability for a crash. We also review two other models including the competition between imitation and contrarian behavior and between value investors and technical analysts. The most important message is the discovery of robust and universal signatures of the approach to crashes. These precursory

  1. Reliability of assessment of critical thinking.

    PubMed

    Allen, George D; Rubenfeld, M Gaie; Scheffer, Barbara K

    2004-01-01

    Although clinical critical thinking skills and behaviors are among the most highly sought characteristics of BSN graduates, they remain among the most difficult to teach and assess. Three reasons for this difficulty have been (1) lack of agreement among nurse educators as to the definition of critical thinking, (2) low correlation between clinical critical thinking and existing standardized tests of critical thinking, and (3) poor reliability in scoring other evidences of critical thinking, such as essays. This article first describes a procedure for teaching critical thinking that is based on a consensus definition of 17 dimensions of critical thinking in clinical nursing practice. This procedure is easily taught to nurse educators and can be flexibly and inexpensively incorporated into any undergraduate nursing curriculum. We then show that students' understanding and use of these dimensions can be assessed with high reliability (coefficient alpha between 0.7 and 0.8) and with great time efficiency for both teachers and students. By using this procedure iteratively across semesters, students can develop portfolios demonstrating attainment of competence in clinical critical thinking, and educators can obtain important summary evaluations of the degree to which their graduates have succeeded in this important area of their education.

  2. Nutritional interventions in critical illness.

    PubMed

    Powell-Tuck, Jeremy

    2007-02-01

    The metabolism of critical illness is characterised by a combination of starvation and stress. There is increased production of cortisol, catecholamines, glucagon and growth hormone and increased insulin-like growth factor-binding protein-1. Phagocytic, epithelial and endothelial cells elaborate reactive oxygen and nitrogen species, chemokines, pro-inflammatory cytokines and lipid mediators, and antioxidant depletion ensues. There is hyperglycaemia, hyperinsulinaemia, hyperlactataemia, increased gluconeogenesis and decreased glycogen production. Insulin resistance, particularly in relation to the liver, is marked. The purpose of nutritional support is primarily to save life and secondarily to speed recovery by reducing neuropathy and maintaining muscle mass and function. There is debate about the optimal timing of nutritional support for the patient in the intensive care unit. It is generally agreed that the enteral route is preferable if possible, but the dangers of the parenteral route, a route of feeding that remains important in the context of critical illness, may have been over-emphasised. Control of hyperglycaemia is beneficial, and avoidance of overfeeding is emphasised. Growth hormone is harmful. The refeeding syndrome needs to be considered, although it has been little studied in the context of critical illness. Achieving energy balance may not be necessary in the early stages of critical illness, particularly in patients who are overweight or obese. Protein turnover is increased and N balance is often negative in the face of normal nutrient intake; optimal N intakes are the subject of some debate. Supplementation of particular amino acids able to support or regulate the immune response, such as glutamine, may have a role not only for their potential metabolic effect but also for their potential antioxidant role. Doubt remains in relation to arginine supplementation. High-dose mineral and vitamin antioxidant therapy may have a place. PMID:17343768

  3. Translation as Literary Criticism.

    ERIC Educational Resources Information Center

    di Stefano, B. Follkart

    1982-01-01

    It is proposed that literary translation is intrinsically an act of literary criticism. This theory is illustrated by discussion of specific problems in translating Sartre's "La Nausee" and Leonard Forest's "Le pays de la Sagouine," especially the use of verb tense. (MSE)

  4. Conductive Critical Thinking

    ERIC Educational Resources Information Center

    Paetkau, Mark

    2007-01-01

    One of my goals as an instructor is to teach students critical thinking skills. This paper presents an example of a student-led discussion of heat conduction at the first-year level. Heat loss from a human head is calculated using conduction and radiation models. The results of these plausible (but wrong) models of heat transfer contradict what…

  5. Critical Incidents in Negotiation.

    ERIC Educational Resources Information Center

    American Association of School Administrators, Washington, DC.

    This report presents imaginary dialogues between a management team and an employee team and critiques the dialogues to emphasize the significance of situations and episodes that can hasten or hamper a settlement at the negotiation table. Three critical incidents are studied within each developmental phase of the negotiation process: (1) procedural…

  6. Criticizing the Role.

    ERIC Educational Resources Information Center

    Cohen, Arthur M.

    Critics of the community college are justified in challenging unsubstantiated statements about the institution by college spokespersons or in public relations releases disguised as institutional analyses. During the 1960's, for example, increasing enrollments were often cited as evidence of public support for community colleges--without reference…

  7. Creativity and Critical Thinking.

    ERIC Educational Resources Information Center

    Kollen, Patsy Phillips

    How to deal with the absence of creativity and critical thinking in the educational setting is discussed. All efforts to improve education will be futile if we don't take into account the absence of relationship among the participants and between the participants and the content of education. Relationship--i.e., connecting with others and with…

  8. SEMANTICS AND CRITICAL READING.

    ERIC Educational Resources Information Center

    FLANIGAN, MICHAEL C.

    PROFICIENCY IN CRITICAL READING CAN BE ACCELERATED BY MAKING STUDENTS AWARE OF VARIOUS SEMANTIC DEVICES THAT HELP CLARIFY MEANINGS AND PURPOSES. EXCERPTS FROM THE ARTICLE "TEEN-AGE CORRUPTION" FROM THE NINTH-GRADE SEMANTICS UNIT WRITTEN BY THE PROJECT ENGLISH DEMONSTRATION CENTER AT EUCLID, OHIO, ARE USED TO ILLUSTRATE HOW SEMANTICS RELATE TO…

  9. Audience, Style and Criticism

    ERIC Educational Resources Information Center

    Pimm, David; Sinclair, Nathalie

    2009-01-01

    The primary focus for this article involves aspects of professional mathematical writing and examines the possibility of a form of literary criticism in relation to it. By means of examples from contemporary style guides for academic articles in mathematics (AMS, MAA), as well as the writing of mathematicians (Hamilton, Dedekind) from earlier…

  10. Critical Thinking Concept Reconstructed

    ERIC Educational Resources Information Center

    Minter, Mary Kennedy

    2010-01-01

    This paper explores the proposition that teaching of critical thinking (CT) should include: (1) identifying and addressing the many environmental variables acting as barriers to our human thinking, i.e., an open system approach, and (2) utilizing the interrelatedness of the CT building blocks, i.e., creative thinking techniques, levels of…

  11. Replies to Criticisms

    ERIC Educational Resources Information Center

    Hamilton, James R.

    2009-01-01

    In this essay, Hamilton responds to criticisms of his book "The Art of Theater" (Malden, MA: Blackwell, 2007). Acknowledging that he expected that the central proposals in "The Art of Theater" would seem a little strange to philosophers, he reiterates his belief that the three general facts of any theatrical performance are its presentation, its…

  12. Critical Thinking and Learning

    ERIC Educational Resources Information Center

    Mason, Mark

    2007-01-01

    This paper introduces some of the debates in the field of critical thinking by highlighting differences among thinkers such as Siegel, Ennis, Paul, McPeck, and Martin, and poses some questions that arise from these debates. Does rationality transcend particular cultures, or are there different kinds of thinking, different styles of reasoning? What…

  13. Critical Practice: Teaching "Shakespeare."

    ERIC Educational Resources Information Center

    Mellor, Bronwyn; Patterson, Annette

    2000-01-01

    Describes how the authors taught their students to read "Hamlet" from a critical literacy perspective, analyzing how particular readings of texts and characters are constructed or produced; how they are determined by historical and cultural conventions; analyzing values that various readings support or challenge--rather than trying to get closer…

  14. Stateline: Critical Mass

    ERIC Educational Resources Information Center

    Christie, Kathy

    2005-01-01

    In Physics "critical mass" refers to the minimum amount of fissionable material required to sustain a chain reaction. The adoption of state education policy isn't often equated with this concept, but occasionally solutions and ideas seem to gather around a common problem. If the solution at hand is simple, easily understood, and strengthened with…

  15. Light Touch Critical Friendship

    ERIC Educational Resources Information Center

    Swaffield, Sue

    2007-01-01

    Critical friendship is a flexible form of support for school colleagues and one that is increasingly being applied to different contexts, including the New Relationship with Schools and School Improvement Partners. The ESRC/TLRP "Learning How to Learn" (LHTL) project was interested in, among other things, the scaling up of innovation, and…

  16. Critical Skills Survey

    ERIC Educational Resources Information Center

    Education Digest: Essential Readings Condensed for Quick Review, 2010

    2010-01-01

    As the U.S. economy begins to show signs of improvement, executives say they need a workforce fully equipped with skills beyond just the basics of reading, writing, and arithmetic (the three Rs). Skills such as critical thinking and problem solving, communication, collaboration, and creativity and innovation (the four Cs) will become even more…

  17. Educational Criticism and Shamanism.

    ERIC Educational Resources Information Center

    Sevigny, Maurice J.

    1984-01-01

    Critiqued is the article, "Teacher as Shaman: An Educational Criticism," (Studies in Art Education, v25 n1), containing a case study of an art teacher who employs performance-based ritual to stimulate thinking about art's meaning and history. The problem that ethnographic researchers have conveying credibility when summarizing investigations is…

  18. Critical thinking in clinical nurse education: application of Paul's model of critical thinking.

    PubMed

    Andrea Sullivan, E

    2012-11-01

    Nurse educators recognize that many nursing students have difficulty in making decisions in clinical practice. The ability to make effective, informed decisions in clinical practice requires that nursing students know and apply the processes of critical thinking. Critical thinking is a skill that develops over time and requires the conscious application of this process. There are a number of models in the nursing literature to assist students in the critical thinking process; however, these models tend to focus solely on decision making in hospital settings and are often complex to actualize. In this paper, Paul's Model of Critical Thinking is examined for its application to nursing education. I will demonstrate how the model can be used by clinical nurse educators to assist students to develop critical thinking skills in all health care settings in a way that makes critical thinking skills accessible to students.

  19. Stress-Induced Accumulation of DcAOX1 and DcAOX2a Transcripts Coincides with Critical Time Point for Structural Biomass Prediction in Carrot Primary Cultures (Daucus carota L.).

    PubMed

    Campos, M Doroteia; Nogales, Amaia; Cardoso, Hélia G; Kumar, Sarma R; Nobre, Tânia; Sathishkumar, Ramalingam; Arnholdt-Schmitt, Birgit

    2016-01-01

    Stress-adaptive cell plasticity in target tissues and cells for plant biomass growth is important for yield stability. In vitro systems with reproducible cell plasticity can help to identify relevant metabolic and molecular events during early cell reprogramming. In carrot, regulation of the central root meristem is a critical target for yield-determining secondary growth. Calorespirometry, a tool previously identified as promising for predictive growth phenotyping has been applied to measure the respiration rate in carrot meristem. In a carrot primary culture system (PCS), this tool allowed identifying an early peak related with structural biomass formation during lag phase of growth, around the 4th day of culture. In the present study, we report a dynamic and correlated expression of carrot AOX genes (DcAOX1 and DcAOX2a) during PCS lag phase and during exponential growth. Both genes showed an increase in transcript levels until 36 h after explant inoculation, and a subsequent down-regulation, before the initiation of exponential growth. In PCS growing at two different temperatures (21°C and 28°C), DcAOX1 was also found to be more expressed in the highest temperature. DcAOX genes' were further explored in a plant pot experiment in response to chilling, which confirmed the early AOX transcript increase prior to the induction of a specific anti-freezing gene. Our findings point to DcAOX1 and DcAOX2a as being reasonable candidates for functional marker development related to early cell reprogramming. While the genomic sequence of DcAOX2a was previously described, we characterize here the complete genomic sequence of DcAOX1. PMID:26858746

  20. Stress-Induced Accumulation of DcAOX1 and DcAOX2a Transcripts Coincides with Critical Time Point for Structural Biomass Prediction in Carrot Primary Cultures (Daucus carota L.).

    PubMed

    Campos, M Doroteia; Nogales, Amaia; Cardoso, Hélia G; Kumar, Sarma R; Nobre, Tânia; Sathishkumar, Ramalingam; Arnholdt-Schmitt, Birgit

    2016-01-01

    Stress-adaptive cell plasticity in target tissues and cells for plant biomass growth is important for yield stability. In vitro systems with reproducible cell plasticity can help to identify relevant metabolic and molecular events during early cell reprogramming. In carrot, regulation of the central root meristem is a critical target for yield-determining secondary growth. Calorespirometry, a tool previously identified as promising for predictive growth phenotyping has been applied to measure the respiration rate in carrot meristem. In a carrot primary culture system (PCS), this tool allowed identifying an early peak related with structural biomass formation during lag phase of growth, around the 4th day of culture. In the present study, we report a dynamic and correlated expression of carrot AOX genes (DcAOX1 and DcAOX2a) during PCS lag phase and during exponential growth. Both genes showed an increase in transcript levels until 36 h after explant inoculation, and a subsequent down-regulation, before the initiation of exponential growth. In PCS growing at two different temperatures (21°C and 28°C), DcAOX1 was also found to be more expressed in the highest temperature. DcAOX genes' were further explored in a plant pot experiment in response to chilling, which confirmed the early AOX transcript increase prior to the induction of a specific anti-freezing gene. Our findings point to DcAOX1 and DcAOX2a as being reasonable candidates for functional marker development related to early cell reprogramming. While the genomic sequence of DcAOX2a was previously described, we characterize here the complete genomic sequence of DcAOX1.

  1. Stress-Induced Accumulation of DcAOX1 and DcAOX2a Transcripts Coincides with Critical Time Point for Structural Biomass Prediction in Carrot Primary Cultures (Daucus carota L.)

    PubMed Central

    Campos, M. Doroteia; Nogales, Amaia; Cardoso, Hélia G.; Kumar, Sarma R.; Nobre, Tânia; Sathishkumar, Ramalingam; Arnholdt-Schmitt, Birgit

    2016-01-01

    Stress-adaptive cell plasticity in target tissues and cells for plant biomass growth is important for yield stability. In vitro systems with reproducible cell plasticity can help to identify relevant metabolic and molecular events during early cell reprogramming. In carrot, regulation of the central root meristem is a critical target for yield-determining secondary growth. Calorespirometry, a tool previously identified as promising for predictive growth phenotyping has been applied to measure the respiration rate in carrot meristem. In a carrot primary culture system (PCS), this tool allowed identifying an early peak related with structural biomass formation during lag phase of growth, around the 4th day of culture. In the present study, we report a dynamic and correlated expression of carrot AOX genes (DcAOX1 and DcAOX2a) during PCS lag phase and during exponential growth. Both genes showed an increase in transcript levels until 36 h after explant inoculation, and a subsequent down-regulation, before the initiation of exponential growth. In PCS growing at two different temperatures (21°C and 28°C), DcAOX1 was also found to be more expressed in the highest temperature. DcAOX genes’ were further explored in a plant pot experiment in response to chilling, which confirmed the early AOX transcript increase prior to the induction of a specific anti-freezing gene. Our findings point to DcAOX1 and DcAOX2a as being reasonable candidates for functional marker development related to early cell reprogramming. While the genomic sequence of DcAOX2a was previously described, we characterize here the complete genomic sequence of DcAOX1. PMID:26858746

  2. Time resolved study of three ruthenium(II) complexes at micellar surfaces: A new long excited state lifetime probe for determining critical micelle concentration of surfactant nano-aggregates.

    PubMed

    Patra, Digambara; Chaaban, Ahmad H; Darwish, Shaza; Saad, Huda A; Nehme, Ali S; Ghaddar, Tarek H

    2016-02-01

    Three different ruthenium complexes have been synthesized and their luminescence properties in different solvent environments are reported. Luminescence intensities and excited state lifetimes of Ru-I, Ru-II and Ru-III vary with solvent viscosity. The excited state lifetime of Ru-I linearly increases in the viscosity range 1.76-12,100cP. Ru-II shows two linear increases: one in the low and another in the high viscosity ranges, whereas Ru-III illustrates a linear enhancement only in the low viscosity range. Interestingly, luminescence intensities and excited state lifetimes of Ru-I, Ru-II and Ru-III are found to be sensitive to nano-aggregation. However, the surfactant head charge and that of the ruthenium center as well as the hydrophobic tail of the ancillary ligand of the complexes have a great role in deciding the nature of the interaction and on the excited state properties at micellar surfaces. It is proposed that the long lifetime of Ru-III in water could be due to the coiling of the carbon chain of the ancillary ligand around the ruthenium center. At micelle surface, this coiling of the carbon chain is lost due to the parallel alignment with surfactants and thus quenching of the excited state lifetime is seen. Furthermore, it is shown that the variation of the excited state lifetime with respect to the change in surfactant concentration is a result of the formation of micelles from the surfactant monomer, thus, a novel technique for the determination of the critical micelle concentration (cmc) based on the long excited state lifetime of Ru-III located at the micellar nano-aggregates is reported.

  3. Does College Teach Critical Thinking? A Meta-Analysis

    ERIC Educational Resources Information Center

    Huber, Christopher R.; Kuncel, Nathan R.

    2016-01-01

    Educators view critical thinking as an essential skill, yet it remains unclear how effectively it is being taught in college. This meta-analysis synthesizes research on gains in critical thinking skills and attitudinal dispositions over various time frames in college. The results suggest that both critical thinking skills and dispositions improve…

  4. Critical Education, Critical Pedagogies, Marxist Education in the United States

    ERIC Educational Resources Information Center

    Foley, Jean Ann; Morris, Doug; Gounari, Panayota; Agostinone-Wilson, Faith

    2015-01-01

    As critical pedagogy becomes more mainstream on the educational landscape in the United States, it is important to revisit the original tenets of critical pedagogy and explore their current manifestations. Since the beginning of "criticalism" from the theoretical/foundational work of the Frankfurt School of Critical Social Theory,…

  5. Methodology of metal criticality determination.

    PubMed

    Graedel, T E; Barr, Rachel; Chandler, Chelsea; Chase, Thomas; Choi, Joanne; Christoffersen, Lee; Friedlander, Elizabeth; Henly, Claire; Jun, Christine; Nassar, Nedal T; Schechner, Daniel; Warren, Simon; Yang, Man-Yu; Zhu, Charles

    2012-01-17

    A comprehensive methodology has been created to quantify the degree of criticality of the metals of the periodic table. In this paper, we present and discuss the methodology, which is comprised of three dimensions: supply risk, environmental implications, and vulnerability to supply restriction. Supply risk differs with the time scale (medium or long), and at its more complex involves several components, themselves composed of a number of distinct indicators drawn from readily available peer-reviewed indexes and public information. Vulnerability to supply restriction differs with the organizational level (i.e., global, national, and corporate). The criticality methodology, an enhancement of a United States National Research Council template, is designed to help corporate, national, and global stakeholders conduct risk evaluation and to inform resource utilization and strategic decision-making. Although we believe our methodological choices lead to the most robust results, the framework has been constructed to permit flexibility by the user. Specific indicators can be deleted or added as desired and weighted as the user deems appropriate. The value of each indicator will evolve over time, and our future research will focus on this evolution. The methodology has proven to be sufficiently robust as to make it applicable across the entire spectrum of metals and organizational levels and provides a structural approach that reflects the multifaceted factors influencing the availability of metals in the 21st century.

  6. Critical Viscosity of Xenon

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of liquid xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. Resembling a tiny bit of window screen, the oscillator at the heart of CVX-2 will vibrate between two pairs of paddle-like electrodes. The slight bend in the shape of the mesh has no effect on the data. What counts are the mesh's displacement in the xenon fluid and the rate at which the displacement dampens. The unit shown here is encased in a small test cell and capped with a sapphire windown to contain the xenon at high pressure.

  7. Critical dynamics and decoherence

    SciTech Connect

    Damski, Bogdan; Quan, Haitao T; Zurek, Wojciech H

    2009-01-01

    We study dynamics of decoherence in a generic model where the environment is driven and undergoes a quantum phase transition. We model the environment by the Ising chain in the transverse field, and assume that the decohering system is a central spin-1/2. We found that when the environment is quenched slowly through the critical point, the decoherence factor of the central spin undergoes rapid decay that encodes the critical exponents of the environment. We also found that decoherence in a non-equilibrated, kink-contaminated, environment can be stronger than in a vacuum one. We derived a remarkably simple analytical expression that describes post-transition decoherence and predicts periodicities involving all system parameters. This research connects the fields of decoherence, quantum phase transitions, and Kibble-Zurek non-equilibrium dynamics.

  8. Critical branching neural networks.

    PubMed

    Kello, Christopher T

    2013-01-01

    It is now well-established that intrinsic variations in human neural and behavioral activity tend to exhibit scaling laws in their fluctuations and distributions. The meaning of these scaling laws is an ongoing matter of debate between isolable causes versus pervasive causes. A spiking neural network model is presented that self-tunes to critical branching and, in doing so, simulates observed scaling laws as pervasive to neural and behavioral activity. These scaling laws are related to neural and cognitive functions, in that critical branching is shown to yield spiking activity with maximal memory and encoding capacities when analyzed using reservoir computing techniques. The model is also shown to account for findings of pervasive 1/f scaling in speech and cued response behaviors that are difficult to explain by isolable causes. Issues and questions raised by the model and its results are discussed from the perspectives of physics, neuroscience, computer and information sciences, and psychological and cognitive sciences.

  9. Critical care in India.

    PubMed

    Udwadia, F E; Guntupalli, K K; Vidyasagar, D

    1997-04-01

    India is a vast democracy of nearly one billion people. Before the British rule ended in 1947, the life span of an Indian was a mere 21 years. Within a short span of 50 years, it increased to an impressive 63 years, largely due to public health measures initiated by the government. This created a pool of more than 300 million middle class Indians who could afford the benefits of modern and specialized care when needed. Critical care medicine, as practiced in the West, is still confined to large Metropolitan areas. A large pool of expatriate Indian physicians from all over the world are helping bridge the resource gap between the West and India by transfer of technology and providing appropriate training to physicians and paramedical personnel. This article describes the history and current status of development of critical care medicine in India. PMID:9107510

  10. Carahunge - A Critical Assessment

    NASA Astrophysics Data System (ADS)

    González-García, A. César

    Carahunge is a megalithic monument in southern Armenia that has often been acclaimed as the oldest observatory. The monument, composed of dozens of standing stones, has some perforated stones. The direction of the holes has been measured and their orientation is related to the sun, moon, and stars, obtaining a date for the construction of such devices. After a critical review of the methods and conclusions, these are shown as untenable.

  11. Criticality safety training

    SciTech Connect

    Woodruff, S.K.

    1997-06-01

    Criticality safety training is an important element of the Plutonium Facility safety program at Los Alamos National Laboratory. Training consists of student self-study handbooks and hands-on performance-based training in a mock-up laboratory containing gloveboxes, trolley conveyor system, and self-monitoring instruments. A 10-minute video tape and lecture was presented to describe how training in this area is conducted.

  12. Horizon as critical phenomenon

    NASA Astrophysics Data System (ADS)

    Lee, Sung-Sik

    2016-09-01

    We show that renormalization group flow can be viewed as a gradual wave function collapse, where a quantum state associated with the action of field theory evolves toward a final state that describes an IR fixed point. The process of collapse is described by the radial evolution in the dual holographic theory. If the theory is in the same phase as the assumed IR fixed point, the initial state is smoothly projected to the final state. If in a different phase, the initial state undergoes a phase transition which in turn gives rise to a horizon in the bulk geometry. We demonstrate the connection between critical behavior and horizon in an example, by deriving the bulk metrics that emerge in various phases of the U( N ) vector model in the large N limit based on the holographic dual constructed from quantum renormalization group. The gapped phase exhibits a geometry that smoothly ends at a finite proper distance in the radial direction. The geometric distance in the radial direction measures a complexity: the depth of renormalization group transformation that is needed to project the generally entangled UV state to a direct product state in the IR. For gapless states, entanglement persistently spreads out to larger length scales, and the initial state can not be projected to the direct product state. The obstruction to smooth projection at charge neutral point manifests itself as the long throat in the anti-de Sitter space. The Poincare horizon at infinity marks the critical point which exhibits a divergent length scale in the spread of entanglement. For the gapless states with non-zero chemical potential, the bulk space becomes the Lifshitz geometry with the dynamical critical exponent two. The identification of horizon as critical point may provide an explanation for the universality of horizon. We also discuss the structure of the bulk tensor network that emerges from the quantum renormalization group.

  13. Critical Path Web Site

    NASA Technical Reports Server (NTRS)

    Robinson, Judith L.; Charles, John B.; Rummel, John A. (Technical Monitor)

    2000-01-01

    Approximately three years ago, the Agency's lead center for the human elements of spaceflight (the Johnson Space Center), along with the National Biomedical Research Institute (NSBRI) (which has the lead role in developing countermeasures) initiated an activity to identify the most critical risks confronting extended human spaceflight. Two salient factors influenced this activity: first, what information is needed to enable a "go/no go" decision to embark on extended human spaceflight missions; and second, what knowledge and capabilities are needed to address known and potential health, safety and performance risks associated with such missions. A unique approach was used to first define and assess those risks, and then to prioritize them. This activity was called the Critical Path Roadmap (CPR) and it represents an opportunity to develop and implement a focused and evolving program of research and technology designed from a "risk reduction" perspective to prevent or minimize the risks to humans exposed to the space environment. The Critical Path Roadmap provides the foundation needed to ensure that human spaceflight, now and in the future, is as safe, productive and healthy as possible (within the constraints imposed on any particular mission) regardless of mission duration or destination. As a tool, the Critical Path Roadmap enables the decision maker to select from among the demonstrated or potential risks those that are to be mitigated, and the completeness of that mitigation. The primary audience for the CPR Web Site is the members of the scientific community who are interested in the research and technology efforts required for ensuring safe and productive human spaceflight. They may already be informed about the various space life sciences research programs or they may be newcomers. Providing the CPR content to potential investigators increases the probability of their delivering effective risk mitigations. Others who will use the CPR Web Site and its

  14. Critical Path Web Site

    NASA Technical Reports Server (NTRS)

    Robinson, Judith L.; Charles, John B.; Rummel, John A. (Technical Monitor)

    2000-01-01

    Approximately three years ago, the Agency's lead center for the human elements of spaceflight (the Johnson Space Center), along with the National Biomedical Research Institute (NSBRI) (which has the lead role in developing countermeasures) initiated an activity to identify the most critical risks confronting extended human spaceflight. Two salient factors influenced this activity: first, what information is needed to enable a "go/no go" decision to embark on extended human spaceflight missions; and second, what knowledge and capabilities are needed to address known and potential health, safety and performance risks associated with such missions. A unique approach was used to first define and assess those risks, and then to prioritize them. This activity was called the Critical Path Roadmap (CPR) and it represents an opportunity to develop and implement a focused and evolving program of research and technology designed from a "risk reduction" perspective to prevent or minimize the risks to humans exposed to the space environment. The Critical Path Roadmap provides the foundation needed to ensure that human spaceflight, now and in the future, is as safe, productive and healthy as possible (within the constraints imposed on any particular mission) regardless of mission duration or destination. As a tool, the Critical Path Roadmap enables the decisionmaker to select from among the demonstrated or potential risks those that are to be mitigated, and the completeness of that mitigation. The primary audience for the CPR Web Site is the members of the scientific community who are interested in the research and technology efforts required for ensuring safe and productive human spaceflight. They may already be informed about the various space life sciences research programs or they may be newcomers. Providing the CPR content to potential investigators increases the probability of their delivering effective risk mitigations. Others who will use the CPR Web Site and its content

  15. Monetizing illness: the influence of disability assistance priming on how we evaluate the health symptoms of others.

    PubMed

    O'Brien, Rourke L

    2015-03-01

    For low-income families in the United States disability assistance has emerged as a critical income support program in the post-welfare reform era. This article explores how this monetization of illness-tying receipt of government assistance to a physical or mental condition-influences how individuals evaluate the severity of another individual's health symptoms. Using data collected through a nationally representative survey experiment of adults in the United States (n = 1005) in May 2013, I find that respondents who are primed to consider the existence of disability assistance are less likely to rate the symptoms described in a hypothetical vignette as severe relative to the control group. I find evidence that this effect holds for both physical (back pain) and mental (depression) conditions for adults and behavioral conditions (ADHD) in children. Moreover, respondents in the experimental group were more likely to blame the individual for her health condition and this measure was found to partially mediate the effect of the disability assistance prime. These findings have important implications for researchers, policymakers and medical practitioners by illustrating how premising state assistance on a health condition may in turn shape how individuals evaluate the health symptoms of others. PMID:25577289

  16. Abnormalities of Thyroid Hormone Metabolism during Systemic Illness: The Low T3 Syndrome in Different Clinical Settings

    PubMed Central

    Zantut-Wittmann, Denise Engelbrecht

    2016-01-01

    Thyroid hormone abnormalities are common in critically ill patients. For over three decades, a mild form of these abnormalities has been described in patients with several diseases under outpatient care. These alterations in thyroid hormone economy are a part of the nonthyroidal illness and keep an important relationship with prognosis in most cases. The main feature of this syndrome is a fall in free triiodothyronine (T3) levels with normal thyrotropin (TSH). Free thyroxin (T4) and reverse T3 levels vary according to the underlying disease. The importance of recognizing this condition in such patients is evident to physicians practicing in a variety of specialties, especially general medicine, to avoid misdiagnosing the much more common primary thyroid dysfunctions and indicating treatments that are often not beneficial. This review focuses on the most common chronic diseases already known to present with alterations in serum thyroid hormone levels. A short review of the common pathophysiology of the nonthyroidal illness is followed by the clinical and laboratorial presentation in each condition. Finally, a clinical case vignette and a brief summary on the evidence about treatment of the nonthyroidal illness and on the future research topics to be addressed are presented. PMID:27803712

  17. Challenges in Critical Language Teaching

    ERIC Educational Resources Information Center

    Pessoa, Rosane Rocha; de Urzeda Freitas, Marco Tulio

    2012-01-01

    This article is based on the conception of language teaching as a liberatory practice. Drawing on some principles of critical pedagogy (Ellsworth, 1992; Freire, 2005; hooks, 1994; Norton & Toohey, 2004), critical applied linguistics (Pennycook, 1990, 2001), critical language teaching (Ferreira, 2006; Pennycook, 1999), and critical language teacher…

  18. Morphogenesis at criticality?

    NASA Astrophysics Data System (ADS)

    Krotov, Dmitry; Dubuis, Julien; Wieschaus, Eric; Gregor, Thomas; Bialek, William

    2013-03-01

    Embryonic development of many multicellular organisms begins with the generation of spatially varying patterns of morphogens that encode the body plan of the future organism. We study the spatial pattern formed by the gap gene proteins in the early fruit fly embryo, which is anchored by ``crossing points'' between expression levels of different genes; these are thought to result from mutual repression. We explore a broad class of models for such interacting genes and show that the parameters implied implied by recent quantitative measurements are non-generic, but rather tuned to certain values, so that the entire gap gene network operates close to the critical surface in its phase diagram. We develop a mean field description of this system as well as derive signatures of critical behavior in the structure of expression noise. One such signature is that fluctuations are dominated by a single ``massless'' mode, so that fluctuations of expression levels of different genes are highly correlated/anticorrelated. We find a surprisingly high degree of anticorrelation in the real experimental data. These results suggest an interesting possibility that the network of genes responsible for development is operating near criticality.

  19. [The critical scientists' voice].

    PubMed

    Lewgoy, F

    2000-01-01

    The intricate debate over genetically modified organisms (GMOs) involves powerful economic interests, as well as ethical, legal, emotional and scientific aspects, some of which are dealt with in this paper.(It is possible to identify two main groups of scientists across the GMOs divide: the triumphalist and the critical group.) Scientists in the triumphalist group state that GMOs and their derivatives are safe for the environment and do not offer health hazards any more than similar, non-genetically modified, products. This view is disputed by the critical scientists, who are prompted by the scarcity of studies on the environmental impacts and toxicity of GMOs, and who point out flaws in tests performed by the same companies which hold the patents. They are also critical of the current state of the process of gene transference, lacking accuracy, a fact which, coupled with the scant knowledge available about 97% of the genome functions, may produce unforseeable effects with risks for the environment and public health yet to be assessed. Examples of such effects are: the transference of alien genes [??] to other species, the emergence of toxins, the creation of new viruses, the impacts on beneficial insects and on biodiversity in general.

  20. Relative Critical Points

    NASA Astrophysics Data System (ADS)

    Lewis, Debra

    2013-05-01

    Relative equilibria of Lagrangian and Hamiltonian systems with symmetry are critical points of appropriate scalar functions parametrized by the Lie algebra (or its dual) of the symmetry group. Setting aside the structures - symplectic, Poisson, or variational - generating dynamical systems from such functions highlights the common features of their construction and analysis, and supports the construction of analogous functions in non-Hamiltonian settings. If the symmetry group is nonabelian, the functions are invariant only with respect to the isotropy subgroup of the given parameter value. Replacing the parametrized family of functions with a single function on the product manifold and extending the action using the (co)adjoint action on the algebra or its dual yields a fully invariant function. An invariant map can be used to reverse the usual perspective: rather than selecting a parametrized family of functions and finding their critical points, conditions under which functions will be critical on specific orbits, typically distinguished by isotropy class, can be derived. This strategy is illustrated using several well-known mechanical systems - the Lagrange top, the double spherical pendulum, the free rigid body, and the Riemann ellipsoids - and generalizations of these systems.

  1. Anaerobic critical velocity in four swimming techniques.

    PubMed

    Neiva, H P; Fernandes, R J; Vilas-Boas, J P

    2011-03-01

    The aim of this study was to assess critical velocity in order to control and evaluate anaerobic swimming training. 51 highly trained male swimmers performed maximal 15, 25, 37.5 and 50 m in the 4 swimming techniques to determine critical velocity from the distance-time relationship. Anaerobic critical velocity was compared with 100 m swimming performance and corresponding partials. Complementarily, 9 swimmers performed a 6×50 m (4 min interval) training series at front crawl individual anaerobic critical velocity, capillary blood lactate concentrations being assessed after each repetition. The mean±SD values of anaerobic critical velocity and its relationship with the 100 m event were: 1.61±0.07 (r=0.60, p=0.037), 1.53±0.05 (r=0.81, p=0.015), 1.33±0.05 (r=0.83, p=0.002), and 1.75±0.05 (r=0.74, p=0.001), for butterfly, backstroke, breaststroke and front crawl, respectively. However, differences between anaerobic critical velocity and performance were observed (with exception of the second half of the 100 m swimming events in breaststroke and butterfly). Lactate concentration values at the end of the series were 14.52±1.06 mmol.l (-1), which suggests that it was indeed an anaerobic training set. In this sense, anaerobic critical velocity can be used to prescribe anaerobic training intensities.

  2. Anaerobic critical velocity in four swimming techniques.

    PubMed

    Neiva, H P; Fernandes, R J; Vilas-Boas, J P

    2011-03-01

    The aim of this study was to assess critical velocity in order to control and evaluate anaerobic swimming training. 51 highly trained male swimmers performed maximal 15, 25, 37.5 and 50 m in the 4 swimming techniques to determine critical velocity from the distance-time relationship. Anaerobic critical velocity was compared with 100 m swimming performance and corresponding partials. Complementarily, 9 swimmers performed a 6×50 m (4 min interval) training series at front crawl individual anaerobic critical velocity, capillary blood lactate concentrations being assessed after each repetition. The mean±SD values of anaerobic critical velocity and its relationship with the 100 m event were: 1.61±0.07 (r=0.60, p=0.037), 1.53±0.05 (r=0.81, p=0.015), 1.33±0.05 (r=0.83, p=0.002), and 1.75±0.05 (r=0.74, p=0.001), for butterfly, backstroke, breaststroke and front crawl, respectively. However, differences between anaerobic critical velocity and performance were observed (with exception of the second half of the 100 m swimming events in breaststroke and butterfly). Lactate concentration values at the end of the series were 14.52±1.06 mmol.l (-1), which suggests that it was indeed an anaerobic training set. In this sense, anaerobic critical velocity can be used to prescribe anaerobic training intensities. PMID:21165797

  3. CRITICALITY HAZOP EFFICIENTLY EVALUATING HAZARDS OF NEW OR REVISED CRITICALITY SAFETY EVALUATIONS

    SciTech Connect

    CARSON DM

    2008-04-15

    The 'Criticality HazOp' technique, as developed at Hanford's Plutonium Finishing Plant (PFP), has allowed for efficiencies enabling shortening of the time necessary to complete new or revised criticality safety evaluation reports (CSERs). For example, in the last half of 2007 at PFP, CSER revisions undergoing the 'Criticality HazOp' process were completed at a higher rate than previously achievable. The efficiencies gained through use of the 'Criticality HazOp' process come from the preliminary narrowing of potential scenarios for the Criticality analyst to fully evaluate in preparation of the new or revised CSER, and from the use of a systematized 'Criticality HazOp' group assessment of the relevant conditions to show which few parameter/condition/deviation combinations actually require analytical effort. The 'Criticality HazOp' has not only provided efficiencies of time, but has brought to criticality safety evaluation revisions the benefits of a structured hazard evaluation method and the enhanced insight that may be gained from direct involvement of a team in the process. In addition, involved personnel have gained a higher degree of confidence and understanding of the resulting CSER product.

  4. Autism: A “Critical Period” Disorder?

    PubMed Central

    LeBlanc, Jocelyn J.; Fagiolini, Michela

    2011-01-01

    Cortical circuits in the brain are refined by experience during critical periods early in postnatal life. Critical periods are regulated by the balance of excitatory and inhibitory (E/I) neurotransmission in the brain during development. There is now increasing evidence of E/I imbalance in autism, a complex genetic neurodevelopmental disorder diagnosed by abnormal socialization, impaired communication, and repetitive behaviors or restricted interests. The underlying cause is still largely unknown and there is no fully effective treatment or cure. We propose that alteration of the expression and/or timing of critical period circuit refinement in primary sensory brain areas may significantly contribute to autistic phenotypes, including cognitive and behavioral impairments. Dissection of the cellular and molecular mechanisms governing well-established critical periods represents a powerful tool to identify new potential therapeutic targets to restore normal plasticity and function in affected neuronal circuits. PMID:21826280

  5. Criticality validation for burnup credit using recycle Pu criticals

    SciTech Connect

    Fuentes, E.; Lancaster, D.

    1997-04-01

    A set of 23 additional critical experiments were analyzed to provide additional input to the criticality validation portion of spent fuel cask analysis. The results of this analyses were combined with the previously analyzed criticals to determine the upper safety limit on k{sub eff}. The combined set of criticals can be used used for criticality validation for burnup credit, and are better suited for the range of isotopics in spent nuclear fuels. A trend observed in the analysis was that the calculated k{sub eff} deviates from the criticals in the positive direction, implying that increased burnup results in increased safety margin. 6 refs., 2 figs., 1 tab.

  6. The timing of the human circadian clock is accurately represented by the core body temperature rhythm following phase shifts to a three-cycle light stimulus near the critical zone

    NASA Technical Reports Server (NTRS)

    Jewett, M. E.; Duffy, J. F.; Czeisler, C. A.

    2000-01-01

    A double-stimulus experiment was conducted to evaluate the phase of the underlying circadian clock following light-induced phase shifts of the human circadian system. Circadian phase was assayed by constant routine from the rhythm in core body temperature before and after a three-cycle bright-light stimulus applied near the estimated minimum of the core body temperature rhythm. An identical, consecutive three-cycle light stimulus was then applied, and phase was reassessed. Phase shifts to these consecutive stimuli were no different from those obtained in a previous study following light stimuli applied under steady-state conditions over a range of circadian phases similar to those at which the consecutive stimuli were applied. These data suggest that circadian phase shifts of the core body temperature rhythm in response to a three-cycle stimulus occur within 24 h following the end of the 3-day light stimulus and that this poststimulus temperature rhythm accurately reflects the timing of the underlying circadian clock.

  7. Rethinking Critical Adsorption

    NASA Astrophysics Data System (ADS)

    Franck, Carl; Peach, Sarah; Polak, Robert D.

    1996-03-01

    Recent reflectivity experiments on near-critical mixtures of carbon disulfide and nitromethane contained in glass cells footnote Niraj S. Desai, Sarah Peach, and Carl Franck, Phys. Rev. E 52, 4129 (1995) have shown that preferential adsorption of one liquid component onto the wall can be controlled by chemical modification of the glass. The glass was treated with varying amounts of hexamethyldisilazane to decrease surface polarity and therefore enhance the adsorption of carbon disulfide in a surprisingly continuous way. The effect of the glass wall on the local liquid composition can be described by two different scaling hypotheses: using a short range field on the liquid closest to the wall, or pinning the amplitude of the order parameter at the surface. We have found that only the second approach is consistent with the experimental data, although this is difficult to reconcile with observed wetting critical phenomena. We also have reexamined the issue of substrate inhomogeneity and conclude that the substrates were indeed homogeneous on relevant length scales. Supported by the NSF under DMR-9320910 and the central facilities of the Materials Science Center at Cornell University.

  8. Are there critical periods for musical development?

    PubMed

    Trainor, Laurel J

    2005-04-01

    A critical period can be defined as a developmental window during which specific experience has a greater effect than at other times. Musical behavior involves many skills, including the basic encoding of pitch and time information, understanding scale and harmonic structure, performance, interpretation, and composition. We review studies of genetics, behavior, and brain structure and function in conjunction with the experiences of auditory deprivation and musical enrichment, and conclude that there is more supporting evidence for critical periods for basic than for more complex aspects of musical pitch acquisition. Much remains unknown about the mechanisms of interaction between genetic and experiential factors that create critical periods, but it is clear that there are multiple pathways for achieving musical expertise.

  9. The IARC monographs: critics and controversy.

    PubMed

    Samet, Jonathan M

    2015-07-01

    The monograph program of the International Agency for Research on Cancer (IARC), which relies on the efforts of volunteer Working Groups, uses a transparent approach to evaluate the carcinogenicity of agents for which scoping has determined that there is sufficient evidence to warrant a review. Because of the potentially powerful implications of the conclusions of the monographs and the sometimes challenging nature of the evidence reviewed, the monographs and the IARC process have been criticized from time to time. This commentary describes the IARC monograph process and addresses recent criticisms of the program, drawing on a recent defense of the program authored by 124 researchers. These authors concluded that the IARC processes are robust and transparent and not flawed and biased as suggested by some critics. PMID:25943987

  10. Critical Literature Pedagogy: Teaching Canonical Literature for Critical Literacy

    ERIC Educational Resources Information Center

    Borsheim-Black, Carlin; Macaluso, Michael; Petrone, Robert

    2014-01-01

    This article introduces Critical Literature Pedagogy (CLP), a pedagogical framework for applying goals of critical literacy within the context of teaching canonical literature. Critical literacies encompass skills and dispositions to understand, question, and critique ideological messages of texts; because canonical literature is often…

  11. Viruddha Ahara: A critical view.

    PubMed

    Sabnis, Mukund

    2012-07-01

    Viruddha Ahara is a unique concept described in Ayurveda. The present article deals with the critical review of Viruddha Ahara referred in terms of food-food interactions, food processing interactions. Ayurveda clearly defines that certain diet and its combinations, which interrupts the metabolism of tissue, which inhibits the process of formation of tissue and which have the opposite property to the tissue are called as Viruddha Anna or incompatible diet. The food which is wrong in combination, which has undergone wrong processing, which is consumed in incorrect dose, which is consumed in incorrect time of day and in wrong season can lead to Viruddha Ahara. The article narrates the modern perspective of Samskar Viruddha, Veerya Viruddha, Samyoga Viruddha, and so on. It also enlists a variety of incompatible dietary articles consumed in today's day-to-day life and its hazardous effects on health. PMID:23723637

  12. Viruddha Ahara: A critical view

    PubMed Central

    Sabnis, Mukund

    2012-01-01

    Viruddha Ahara is a unique concept described in Ayurveda. The present article deals with the critical review of Viruddha Ahara referred in terms of food–food interactions, food processing interactions. Ayurveda clearly defines that certain diet and its combinations, which interrupts the metabolism of tissue, which inhibits the process of formation of tissue and which have the opposite property to the tissue are called as Viruddha Anna or incompatible diet. The food which is wrong in combination, which has undergone wrong processing, which is consumed in incorrect dose, which is consumed in incorrect time of day and in wrong season can lead to Viruddha Ahara. The article narrates the modern perspective of Samskar Viruddha, Veerya Viruddha, Samyoga Viruddha, and so on. It also enlists a variety of incompatible dietary articles consumed in today's day-to-day life and its hazardous effects on health. PMID:23723637

  13. NASA Critical Facilities Maintenance Assessment

    NASA Technical Reports Server (NTRS)

    Oberhettinger, David J.

    2006-01-01

    Critical Facilities Maintenance Assessment (CFMA) was first implemented by NASA following the March 2000 overtest of the High Energy Solar Spectroscopic Imager (HESSI) spacecraft. A sine burst dynamic test using a 40 year old shaker failed. Mechanical binding/slippage of the slip table imparted 10 times the planned force to the test article. There was major structural damage to HESSI. The mechanical "health" of the shaker had not been assessed and tracked to assure the test equipment was in good working order. Similar incidents have occurred at NASA facilities due to inadequate maintenance (e.g., rainwater from a leaky roof contaminated an assembly facility that housed a spacecraft). The HESSI incident alerted NASA to the urgent need to identify inadequacies in ground facility readiness and maintenance practices. The consequences of failures of ground facilities that service these NASA systems are severe due to the high unit value of NASA products.

  14. Optimal Management of the Critically Ill: Anaesthesia, Monitoring, Data Capture, and Point-of-Care Technological Practices in Ovine Models of Critical Care

    PubMed Central

    Shekar, Kiran; Tung, John-Paul; Dunster, Kimble R.; Platts, David; Watts, Ryan P.; Gregory, Shaun D.; Simonova, Gabriela; McDonald, Charles; Hayes, Rylan; Bellpart, Judith; Timms, Daniel; Fung, Yoke L.; Toon, Michael; Maybauer, Marc O.; Fraser, John F.

    2014-01-01

    Animal models of critical illness are vital in biomedical research. They provide possibilities for the investigation of pathophysiological processes that may not otherwise be possible in humans. In order to be clinically applicable, the model should simulate the critical care situation realistically, including anaesthesia, monitoring, sampling, utilising appropriate personnel skill mix, and therapeutic interventions. There are limited data documenting the constitution of ideal technologically advanced large animal critical care practices and all the processes of the animal model. In this paper, we describe the procedure of animal preparation, anaesthesia induction and maintenance, physiologic monitoring, data capture, point-of-care technology, and animal aftercare that has been successfully used to study several novel ovine models of critical illness. The relevant investigations are on respiratory failure due to smoke inhalation, transfusion related acute lung injury, endotoxin-induced proteogenomic alterations, haemorrhagic shock, septic shock, brain death, cerebral microcirculation, and artificial heart studies. We have demonstrated the functionality of monitoring practices during anaesthesia required to provide a platform for undertaking systematic investigations in complex ovine models of critical illness. PMID:24783206

  15. Controlling superconductivity by tunable quantum critical points.

    PubMed

    Seo, S; Park, E; Bauer, E D; Ronning, F; Kim, J N; Shim, J-H; Thompson, J D; Park, Tuson

    2015-03-04

    The heavy fermion compound CeRhIn5 is a rare example where a quantum critical point, hidden by a dome of superconductivity, has been explicitly revealed and found to have a local nature. The lack of additional examples of local types of quantum critical points associated with superconductivity, however, has made it difficult to unravel the role of quantum fluctuations in forming Cooper pairs. Here, we show the precise control of superconductivity by tunable quantum critical points in CeRhIn5. Slight tin-substitution for indium in CeRhIn5 shifts its antiferromagnetic quantum critical point from 2.3 GPa to 1.3 GPa and induces a residual impurity scattering 300 times larger than that of pure CeRhIn5, which should be sufficient to preclude superconductivity. Nevertheless, superconductivity occurs at the quantum critical point of the tin-doped metal. These results underline that fluctuations from the antiferromagnetic quantum criticality promote unconventional superconductivity in CeRhIn5.

  16. Controlling superconductivity by tunable quantum critical points.

    PubMed

    Seo, S; Park, E; Bauer, E D; Ronning, F; Kim, J N; Shim, J-H; Thompson, J D; Park, Tuson

    2015-01-01

    The heavy fermion compound CeRhIn5 is a rare example where a quantum critical point, hidden by a dome of superconductivity, has been explicitly revealed and found to have a local nature. The lack of additional examples of local types of quantum critical points associated with superconductivity, however, has made it difficult to unravel the role of quantum fluctuations in forming Cooper pairs. Here, we show the precise control of superconductivity by tunable quantum critical points in CeRhIn5. Slight tin-substitution for indium in CeRhIn5 shifts its antiferromagnetic quantum critical point from 2.3 GPa to 1.3 GPa and induces a residual impurity scattering 300 times larger than that of pure CeRhIn5, which should be sufficient to preclude superconductivity. Nevertheless, superconductivity occurs at the quantum critical point of the tin-doped metal. These results underline that fluctuations from the antiferromagnetic quantum criticality promote unconventional superconductivity in CeRhIn5. PMID:25737108

  17. DEVELOPMENT OF PROTOCOLS TO IDENTIFY CRITICAL ECOSYSTEMS

    EPA Science Inventory

    Healthy, functioning ecosystems are critical to the sustainability of human and natural communities, but the identification of areas of healthy ecosystems in an area as large as Region 5 is difficult due to time and information constraints. Geographic Information Systems (GIS) a...

  18. Critical Instance Analysis of News English Discourse

    ERIC Educational Resources Information Center

    Pang, Hongmei; Wu, Sijun

    2009-01-01

    Critical discourse analysis (CDA) thought that the discourse was concrete social practice, and the language served for the potency, and the discourse embodied the ideology. Two presses about the case that the US Mattel Toy Company recalled toys "Made in China" in Washington Post (newspaper) and New York Times (newspaper) were taken as…

  19. Process Mapping: Tools, Techniques, & Critical Success Factors.

    ERIC Educational Resources Information Center

    Kalman, Howard K.

    2002-01-01

    Explains process mapping as an analytical tool and a process intervention that performance technologists can use to improve human performance by reducing error variance. Highlights include benefits of process mapping; and critical success factors, including organizational readiness, time commitment by participants, and the availability of a…

  20. The Moral Imperative of Criticism

    ERIC Educational Resources Information Center

    Hillbruner, Anthony

    1975-01-01

    Elaborates on the ethical responsibility of the rhetorical critic and teacher. The role that moral values play in the criticism process are examined in the literature, history and philosophy disciplines. (MH)

  1. Creative critical-thinking strategies.

    PubMed

    Chubinski, S

    1996-01-01

    Are you looking for strategies to teach critical thinking? The author presents a variety of quick, creative strategies to facilitate teaching critical-thinking skills. These strategies engage students in their learning and are adaptable to any nursing course.

  2. Critical Density Interaction Studies

    SciTech Connect

    Young, P; Baldis, H A; Cheung, P; Rozmus, W; Kruer, W; Wilks, S; Crowley, S; Mori, W; Hansen, C

    2001-02-14

    Experiments have been performed to study the propagation of intense laser pulses to high plasma densities. The issue of self-focusing and filamentation of the laser pulse as well as developing predictive capability of absorption processes and x-ray conversion efficiencies is important for numerous programs at the Laboratory, particularly Laser Program (Fast Ignitor and direct-drive ICF) and D&NT (radiography, high energy backlighters and laser cutting). Processes such as resonance absorption, profile modification, linear mode conversion, filamentation and stimulated Brillouin scattering can occur near the critical density and can have important effects on the coupling of laser light to solid targets. A combination of experiments have been used to study the propagation of laser light to high plasma densities and the interaction physics of intense laser pulses with solid targets. Nonparaxial fluid codes to study nonstationary behavior of filamentation and stimulated Brillouin scattering at high densities have also been developed as part of this project.

  3. Actuating critical care therapeutics.

    PubMed

    Stone, David J; Csete, Marie

    2016-10-01

    Viewing the intensive care unit (ICU) as a control system with inputs (patients) and outputs (outcomes), we focus on actuation (therapies) of the system and how to enhance our understanding of status of patients and their trajectory in the ICU. To incorporate the results of these analytics meaningfully, we feel that a reassessment of predictive scoring systems and of ways to optimally characterize and display the patient's "state space" to clinicians is important. Advances in sensing (diagnostics) and computation have not yet led to significantly better actuation, and so we focus on ways that data can be used to improve actuation in the ICU, in particular by following therapeutic burden along with disease severity. This article is meant to encourage discussion about how the critical care community can best deal with the data they see each day, and prepare for recommendations that will inevitably arise from application of major federal and state initiatives in big data analytics and precision medicine.

  4. Critical CRBR core pressure

    SciTech Connect

    Ju, F.D.

    1980-06-01

    The conditions are detailed under which gas pressure will cause or initiate failure in the structural containment of the fuel core. The Clinch River Breeder Reactor Plant is the prototype structure. Two general classes of problems have been studied, representing two entirely distinct configurations of containment failure. The first model determines the minimum pressure to lift a portion or the entire core from its containment. The second model estimates the critical pressure above which the fuel rods interior to the hexagonal fuel can warp, leading to blockage of the gas passages. Such blockage might cause further buildup of the gas pressure to a level causing the failure of the fuel rod containment in the hexagonal fuel container.

  5. Against the Bureaucratization of Criticism.

    ERIC Educational Resources Information Center

    Nothstine, William L.; Copeland, Gary A.

    The proliferation of critics and critical approaches has produced a trend toward fragmentation and isolation among the practitioners involved. A suggestive counter-trend indicates that there is intense curiosity among critics to watch colleagues encounter texts, grapple with the preliminary questions of stance and method, and share the experience…

  6. A Critically Reflective Social Studies?

    ERIC Educational Resources Information Center

    Clarke, Marge

    1990-01-01

    Examines social studies in the twenty-first century from a critical theory perspective. Traces critical reflection's origins from Marxist educational theories to Jurgen Habermas's critical theory. Highlights Fred Newmann's curricular model, "Education for Citizen Action," for developing competent action in public affairs. Advocates infusing…

  7. Word Recognition and Critical Reading.

    ERIC Educational Resources Information Center

    Groff, Patrick

    1991-01-01

    This article discusses the distinctions between literal and critical reading and explains the role that word recognition ability plays in critical reading behavior. It concludes that correct word recognition provides the raw material on which higher order critical reading is based. (DB)

  8. Critical Quantitative Inquiry in Context

    ERIC Educational Resources Information Center

    Stage, Frances K.; Wells, Ryan S.

    2014-01-01

    This chapter briefly traces the development of the concept of critical quantitative inquiry, provides an expanded conceptualization of the tasks of critical quantitative research, offers theoretical explanation and justification for critical research using quantitative methods, and previews the work of quantitative criticalists presented in this…

  9. What Is Critical about Sociology?

    ERIC Educational Resources Information Center

    Buechler, Steven

    2008-01-01

    Critical thinking is often presented as a generic technique. This article develops an alternative that links critique more closely to the sociological perspective. I suggest three answers to the above question: that the sociological perspective is critical for comprehending complex issues, that all sociology is implicitly critical by virtue of its…

  10. Turbidity of a near-critical ionic fluid

    SciTech Connect

    Narayanan, T.; Pitzer, K.S.

    1994-11-01

    We report the critical behavior of osmotic compressibility ({chi}{sub T}), that was deduced from turbidity, in an ionic fluid mixture comprised of tetra-n-butyl-ammonium picrate in a low dielectric solvent, 1-dodecanol. The liquid-liquid phase separation in this system is driven, predominantly, by Coulombic interactions. Measurements covered the reduced temperature, t, range 7 {times} 10{sup -5} {<=} t {<=} 7 {times} 10{sup -2}. The critical behavior of {chi}{sub T} indicates a crossover from the mean-field to the Ising critical exponent, as the critical temperature (T{sub c}) is approached.

  11. Timing of Acute Palliative Care Consultation in Critically Ill Patients

    ClinicalTrials.gov

    2016-08-03

    Multiple Organ Failure; End Stage Cardiac Failure; End Stage Chronic Obstructive Airways Disease; Chronic Kidney Disease Stage 5; Hepatic Encephalopathy; Sepsis; Dementia; Multiple Sclerosis; Parkinson's Disease; In-Hospital Cardiac Arrest; Solid Organ Cancer

  12. Critical Time: Earthquake Response Planning and Schools. [Videotape].

    ERIC Educational Resources Information Center

    Federal Emergency Management Agency, Washington, DC.

    A videotape that describes what earthquakes are, and examines the disaster planning schools can develop during the first few minutes following an earthquake to assure students and staff survive. The kinds of destruction likely to happen during a damaging earthquake are highlighted. The videotape stresses the need for children and staff to know…

  13. Notes for a Dialogue on Art Education in Critical Times

    ERIC Educational Resources Information Center

    Desai, Dipti; Chalmers, Graeme

    2007-01-01

    Schools have always been subject to an overwhelming variety of socio-political demands, which shift in response to the political climate--impacting art education in different ways. The current debate on social and political issues in art education is not new. Beginning with McFee (1966), and particularly since the 1970s, there has been a growing…

  14. [Enteral nutrition and the critically ill patient].

    PubMed

    Planas, M

    1999-09-01

    Critically ill patients often suffer from malnutrition y loss of muscle weight throughout the whole time they are ill, even when they receive nutritional therapy, due to the tremendous amount of stress they undergo accompanied by a high degree of hypercatabolism. The most recent theories all coincide in the importance of the intestine as the preferred way for nutrients to enter the bodies of these patients because besides fulfilling its function to absorb and digest nutrients, the intestine plays an important role as a barrier to bacteria and their toxins. For these reasons, enteral nutrition should be the first option to consider whenever we must feed a critically ill patient by artificial means.

  15. Are Earthquakes a Critical Phenomenon?

    NASA Astrophysics Data System (ADS)

    Ramos, O.

    2014-12-01

    Earthquakes, granular avalanches, superconducting vortices, solar flares, and even stock markets are known to evolve through power-law distributed events. During decades, the formalism of equilibrium phase transition has coined these phenomena as critical, which implies that they are also unpredictable. This work revises these ideas and uses earthquakes as the paradigm to demonstrate that slowly driven systems evolving through uncorrelated and power-law distributed avalanches (UPLA) are not necessarily critical systems, and therefore not necessarily unpredictable. By linking the correlation length to the pdf of the distribution, and comparing it with the one obtained at a critical point, a condition of criticality is introduced. Simulations in the classical Olami-Feder-Christensen (OFC) earthquake model confirm the findings, showing that earthquakes are not a critical phenomenon. However, one single catastrophic earthquake may show critical properties and, paradoxically, the emergence of this temporal critical behaviour may eventually carry precursory signs of catastrophic events.

  16. Osteoarthritis: A Critical Review

    PubMed Central

    Onishi, Kentaro; Utturkar, Amol; Chang, Eric; Panush, Richard; Hata, Justin; Perret-Karimi, Danielle

    2015-01-01

    Patients with osteoarthritis (OA) are faced with a barrage of treatment options, from recommendations from friends and social media to medications prescribed by the primary care physician. The purpose of this article is to critically review current approaches to generalized or monoarticular OA based on available evidence and to illustrate multidisciplinary and multimodal treatment strategies for the management of OA. Treatment options assessed for efficacy include patient education; oral and topical pharmacological agents; complementary and alternative medicine; surgery; manual medicine; acupuncture; interventional procedures (corticosteroid injection, viscosupplementation, and pulsed radiofrequency); bracing; assistive devices; physical therapy; and physical modalities. Multidisciplinary and multimodal treatment strategies combined with early detection and prevention strategies provide the best benefit to patients. This review also illustrates that traditional and alternative modalities of treatment can be both synergistic and beneficial. Physicians should be aware of the variety of tools available for the management of OA and the associated symptoms. Those healthcare providers who can best individualize treatment plans for specific patients and inspire their patients to embrace healthy lifestyle modifications will achieve the best results. PMID:25750483

  17. Sepsis in critical care.

    PubMed

    King, Joan E

    2007-03-01

    Sepsis is a syndrome produced by the accelerated activity of the inflammatory immune response, the clotting cascade, and endothelial damage. It is a systematic process that can progress easily into septic shock and MODS. The chemical mediators or cytokines produce a complex self-perpetuating process that impacts all body systems. It is critical for the nurse first to identify patients at risk for developing sepsis and to assess patients who have SIRS and sepsis continually for signs and symptoms of organ involvement and organ dysfunction. Once sepsis has been diagnosed, evidence-based practice indicates initiation of fluid resuscitation. Vasopressor therapy, positive inotropic support, and appropriate antibiotic therapy should be started within the first hour. Within a 6-hour timeframe the goal is stabilization of the CVP, MAP, and UOP to prevent further organ damage. The challenge for nurses caring for septic patients is to support the treatment goals, to prevent added complications including stress ulcers, DVTs, aspiration pneumonia, and the progression to MODS, and to address the patient's and the family's psychosocial needs. As complex as the pathophysiology of sepsis is, the nursing care is equally complex but also rewarding. Patients who previously might have died now recover as vigilant nursing care combines forces with new drug therapies and evidence-based practice guidelines.

  18. Thermionic critical technology investigation

    NASA Astrophysics Data System (ADS)

    Jalichandra, P.; Hamerdinger, R. W.; Anderson, E. A.; Lamp, T. R.; Donovan, B. D.

    The thermionic critical technology investigation was initiated to enrich the technology base for thermionic space nuclear power systems. The focus of this program is on an out-of-core, Romashka type reactor system which can operate in the 5-40-kW range. The Romashka concept uses uranium carbide fuel in graphite trays which are radiatively coupled to planar thermionic converters. After completion of the design and fabrication of two state-of-the-art baseline converters, the baseline converters have been subject to further performance and life testing. To date, converter performance tests have been conducted for emitter temperatures from 1850 to 2000 K. The studies have shown that a thermionic converter with a heat-pipe-cooled collector is capable of high power conversion efficiency. By selecting the rhenium-rhenium system, in a closely spaced ignited mode converter, conversion efficiencies of 14 percent with a cell potential of 0.7 V can be readily attained. The sodium heat pipe provides a buffer against extreme changes in collector temperature due to fluctuations in converter load, one that can be improved upon by loading with an inert gas.

  19. Critical dynamics in microgravity

    SciTech Connect

    Duncan, R.; Boyd, S.; Akau, R.; Gianoulakis, S.

    1996-05-01

    Although many well-controlled experiments have been conducted to measure the static properties of systems near criticality, few experiments have explored the transport properties in systems driven very far away from equilibrium as the transition occurs. Here we propose to measure the thermal gradient across the superfluid (HeII)-normal fluid (HeI) interface in microgravity conditions as a function of the heat flux Q used to make the measurements. Microgravity conditions are required (1) to avoid the hydrostatic pressure variation along the height of the helium column (a concern for Q<0.1 {mu}W {center_dot}cm {sup {minus}2}), (2) avoid convection in He-I for Q> 3 {mu}W {center_dot}cm{sup {minus}2} in our apparatus, and (3) to increase the Q=O interfacial width from its value of a few tens of microns on Earth to about a millimeter in orbit. New technologies described in this paper are under development for this experiment, which is in definition for Space Shuttle flight.

  20. Critical Systems Heuristics

    NASA Astrophysics Data System (ADS)

    Ulrich, Werner; Reynolds, Martin

    Critical systems heuristics (CSH) is a framework for reflective professional practice organised around the central tool of boundary critique. This paper, written jointly by the original developer, Werner Ulrich, and Martin Reynolds, an experienced practitioner of CSH, offers a systematic introduction to the idea and use of boundary critique. Its core concepts are explained in detail and their use is illustrated by means of two case studies from the domain of environmental planning and management. A particular focus is on working constructively with tensions between opposing perspectives as they arise in many situations of professional intervention. These include tensions such as ‘situation' versus ‘system', ‘is' versus ‘ought' judgements, concerns of ‘those involved' versus ‘those affected but not involved', stakeholders' ‘stakes' versus ‘stakeholding issues', and others. Accordingly, boundary critique is presented as a participatory process of unfolding and questioning boundary judgements rather than as an expert-driven process of boundary setting. The paper concludes with a discussion of some essential skills and considerations regarding the practice of boundary critique.

  1. Critical Landau velocity in helium nanodroplets.

    PubMed

    Brauer, Nils B; Smolarek, Szymon; Loginov, Evgeniy; Mateo, David; Hernando, Alberto; Pi, Marti; Barranco, Manuel; Buma, Wybren J; Drabbels, Marcel

    2013-10-11

    The best-known property of superfluid helium is the vanishing viscosity that objects experience while moving through the liquid with speeds below the so-called critical Landau velocity. This critical velocity is generally considered a macroscopic property as it is related to the collective excitations of the helium atoms in the liquid. In the present work we determine to what extent this concept can still be applied to nanometer-scale, finite size helium systems. To this end, atoms and molecules embedded in helium nanodroplets of various sizes are accelerated out of the droplets by means of optical excitation, and the speed distributions of the ejected particles are determined. The measurements reveal the existence of a critical velocity in these systems, even for nanodroplets consisting of only a thousand helium atoms. Accompanying theoretical simulations based on a time-dependent density functional description of the helium confirm and further elucidate this experimental finding.

  2. Evolution of fluctuations near QCD critical point

    SciTech Connect

    Stephanov, M. A.

    2010-03-01

    We propose to describe the time evolution of quasistationary fluctuations near QCD critical point by a system of stochastic Boltzmann-Langevin-Vlasov-type equations. We derive the equations and study the system analytically in the linearized regime. Known results for equilibrium stationary fluctuations as well as the critical scaling of diffusion coefficient are reproduced. We apply the approach to the long-standing question of the fate of the critical point fluctuations during the hadronic rescattering stage of the heavy-ion collision after chemical freeze-out. We find that if conserved particle number fluctuations survive the rescattering, so do, under a certain additional condition, the fluctuations of nonconserved quantities, such as mean transverse momentum. We derive a simple analytical formula for the magnitude of this memory effect.

  3. Critical paths: maximizing patient care coordination.

    PubMed

    Spath, P L

    1995-01-01

    1. With today's emphasis on horizontal and vertical integration of patient care services and the new initiatives prompted by these challenges, OR nurses are considering new methods for managing the perioperative period. One such method is the critical path. 2. A critical path defines an optimal sequencing and timing of interventions by physicians, nurses, and other staff members for a particular diagnosis or procedure, designed to better use resources, maximize quality of care, and minimize delays. 3. Hospitals implementing path-based patient care have reported cost reductions and improved team-work. Critical paths have been shown to reduce patient care costs by improving hospital efficiency, not merely by reducing physician practice variations.

  4. Service Modeling Language Applied to Critical Infrastructure

    NASA Astrophysics Data System (ADS)

    Baldini, Gianmarco; Fovino, Igor Nai

    The modeling of dependencies in complex infrastructure systems is still a very difficult task. Many methodologies have been proposed, but a number of challenges still remain, including the definition of the right level of abstraction, the presence of different views on the same critical infrastructure and how to adequately represent the temporal evolution of systems. We propose a modeling methodology where dependencies are described in terms of the service offered by the critical infrastructure and its components. The model provides a clear separation between services and the underlying organizational and technical elements, which may change in time. The model uses the Service Modeling Language proposed by the W3 consortium for describing critical infrastructure in terms of interdependent services nodes including constraints, behavior, information flows, relations, rules and other features. Each service node is characterized by its technological, organizational and process components. The model is then applied to a real case of an ICT system for users authentication.

  5. Variable-Temperature Critical-Current Measurements

    SciTech Connect

    L. F. Goodrich; T. C. Stauffer

    2009-05-19

    This is the final report of a three year contract that covered 09/19/2005 to 07/14/2008. We requested and received a no cost time extension for the third year, 07/15/2007 to 07/14/2008, to allow DoE to send us funds if they became available during that year. It turned out that we did not receive any funding for the third year. The following paper covers our variable-temperature critical-current measurements. We made transport critical-current (Ic) measurements on commercial multifilamentary Nb3Sn strands at temperatures (T) from 4 to 17 K and magnetic fields (H) from 0 to 14 T. One of the unique features of our measurements is that we can cover a wide range of critical currents from less than 0.1 A to over 700 A.

  6. Anomalous quantum criticality in an itinerant ferromagnet.

    PubMed

    Huang, C L; Fuchs, D; Wissinger, M; Schneider, R; Ling, M C; Scheurer, M S; Schmalian, J; Löhneysen, H V

    2015-01-01

    The dynamics of continuous phase transitions is governed by the dynamic scaling exponent relating the correlation length and correlation time. For transitions at finite temperature, thermodynamic critical properties are independent of the dynamic scaling exponent. In contrast, at quantum phase transitions where the transition temperature becomes zero, static and dynamic properties are inherently entangled by virtue of the uncertainty principle. Consequently, thermodynamic scaling equations explicitly contain the dynamic exponent. Here we report on thermodynamic measurements (as a function of temperature and magnetic field) for the itinerant ferromagnet Sr1-xCaxRuO3 where the transition temperature becomes zero for x=0.7. We find dynamic scaling of the magnetization and specific heat with highly unusual quantum critical dynamics. We observe a small dynamic scaling exponent of 1.76 strongly deviating from current models of ferromagnetic quantum criticality and likely being governed by strong disorder in conjunction with strong electron-electron coupling. PMID:26348932

  7. T-Shaped Frame Critical and Post-Critical Analysis

    NASA Astrophysics Data System (ADS)

    Doicheva, Albena

    2016-03-01

    The paper shows solution of a T-shaped frame, strength- ened with two linear springs, regarding critical and post-critical analysis. The solution is exact using the Euler elastic approach and the frame of reference, originated in the point of column axis inflexion. The derived Numerical results show the effect of the springs strengthening for the crit- ical and the post-critical system behaviour. The influence of the geometry change is analyzed, as well.

  8. Critical Phenomena in Liquid-Liquid Mixtures

    NASA Astrophysics Data System (ADS)

    Jacobs, D. T.

    2000-04-01

    Critical phenomena provide intriguing and essential insight into many issues in condensed matter physics because of the many length scales involved. Large density or concentration fluctuations near a system's critical point effectively mask the identity of the system and produce universal phenomena that have been well studied in simple liquid-vapor and liquid-liquid systems. Such systems have provided useful model systems to test theoretical predictions which can then be extended to more complicated systems. Along various thermodynamic paths, several quantities exhibit a simple power-law dependence close to the critical point. The critical exponents describing these relationships are universal and should depend only on a universality class determined by the order-parameter and spatial dimensionality of the system. Liquid gas, binary fluid mixtures, uniaxial ferromagnetism, polymer-solvent, and protein solutions all belong to the same (Ising model) universality class. The diversity of critical systems that can be described by universal relations indicates that experimental measurements on one system should yield the same information as on another. Our experimental investigations have tested existing theory and also extended universal behavior into new areas. By measuring the coexistence curve, heat capacity, thermal expansion and static light scattering (turbidity) in various liquid-liquid and polymer-solvent systems, we have determined critical exponents and amplitudes that have sometimes confirmed and other times challenged current theory. Recent experiments investigating the heat capacity and light scattering in a liquid-liquid mixture very close to the critical point will be discussed. This research is currently supported by The Petroleum Research Fund and by NASA grant NAG8-1433 with some student support from NSF-DMR 9619406.

  9. Hypomagnesemia in Critically Ill Sepsis Patients

    PubMed Central

    Velissaris, Dimitrios; Karamouzos, Vassilios; Pierrakos, Charalampos; Aretha, Diamanto; Karanikolas, Menelaos

    2015-01-01

    Magnesium (Mg), also known as “the forgotten electrolyte”, is the fourth most abundant cation overall and the second most abundant intracellular cation in the body. Mg deficiency has been implicated in the pathophysiology of many diseases. This article is a review of the literature regarding Mg abnormalities with emphasis on the implications of hypomagnesemia in critical illness and on treatment options for hypomagnesemia in critically ill patients with sepsis. Hypomagnesemia is common in critically ill patients, and there is strong, consistent clinical evidence, largely from observational studies, showing that hypomagnesemia is significantly associated with increased need for mechanical ventilation, prolonged ICU stay and increased mortality. Although the mechanism linking hypomagnesemia with poor clinical outcomes is not known, experimental data suggest mechanisms contributing to such outcomes. However, at the present time, there is no clear evidence that magnesium supplementation improves outcomes in critically ill patients with hypomagnesemia. Large, well-designed clinical trials are needed to evaluate the role of magnesium therapy for improving outcomes in critically ill patients with sepsis. PMID:26566403

  10. The critical mass

    SciTech Connect

    Logan, J.

    1996-05-01

    This article discusses in detail the historical background leading to different lines of scientific thinking in the Allied and in the German scientific communities around the feasibility and development of an atomic bomb. An extensive, parallel time table is given along with discussions of the basic theories of the major players during the conception and development of a nuclear program in both arenas. 35 refs., 11 figs., 5 tabs.

  11. The Liver in Critical Illness.

    PubMed

    Damm, Tessa W; Kramer, David J

    2016-07-01

    Caring for critically ill patients with acute and/or chronic liver dysfunction poses a unique challenge. Proper resuscitation and early consideration for transfer to liver transplant centers have resulted in improved outcomes. Liver support devices and cellular models have not yet shown mortality benefit, but they hold promise in the critical care of patients with liver disease. This article reviews pertinent anatomic and physiologic considerations of the liver in critical illness, followed by a selective review of associated organ dysfunction. PMID:27339681

  12. Critical Viscosity of Xenon investigators

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Dr. Dr. Robert F. Berg (right), principal investigator and Dr. Micheal R. Moldover (left), co-investigator, for the Critical Viscosity of Xenon (CVX/CVX-2) experiment. They are with the National Institutes of Standards and Technology, Gaithersburg, MD. The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. Although it does not easily combine with other chemicals, its viscosity at the critical point can be used as a model for a range of chemicals.

  13. Sharpening your critical thinking skills.

    PubMed

    Kyzer, S P

    1996-01-01

    In the current environment of constant and rapid change in health care, critical thinking is essential. Both personal ability to think critically and a willingness to do so are involved and are related to the individual and to the organization in which the individual works. Knowledge, experience, attitudes, thinking strategies, skills, and an organizational culture that values critical thinking are essential factors in the development and practice of those skills. There is no magic solution. There must be a commitment by all levels of the organization to develop and use the principles and skills of critical thinking. PMID:9110811

  14. Sharpening your critical thinking skills.

    PubMed

    Kyzer, S P

    1996-01-01

    In the current environment of constant and rapid change in health care, critical thinking is essential. Both personal ability to think critically and a willingness to do so are involved and are related to the individual and to the organization in which the individual works. Knowledge, experience, attitudes, thinking strategies, skills, and an organizational culture that values critical thinking are essential factors in the development and practice of those skills. There is no magic solution. There must be a commitment by all levels of the organization to develop and use the principles and skills of critical thinking.

  15. Discipline-Based Art Education: Its Criticisms and Its Critics.

    ERIC Educational Resources Information Center

    Eisner, Elliot W.

    1988-01-01

    Discusses the criticisms of discipline-based art education published in the March 1988 issue of "Art Education." Responds to the arguments of Peter London, Helen Muth, Norma K. Pittard, and Karen Hamblen. States that art education would be better served if the energy devoted to criticism was directed toward constructive ends. (GEA)

  16. A Critical "Critical Inquiry" Proposition in Health and Physical Education

    ERIC Educational Resources Information Center

    Leahy, Deana; O'Flynn, Gabrielle; Wright, Jan

    2013-01-01

    A critical inquiry approach is one of five key characteristics that have shaped the development of the new Australian Curriculum: Health and Physical Education (AC: HPE). However, what this means is open to interpretation. In the various documents leading to the consultation draft AC: HPE and in this document itself, critical inquiry is used in…

  17. Do Critical Thinking Exercises Improve Critical Thinking Skills?

    ERIC Educational Resources Information Center

    Cotter, Ellen M.; Tally, Carrie Sacco

    2009-01-01

    Although textbooks routinely include exercises to improve critical thinking skills, the effectiveness of these exercises has not been closely examined. Additionally, the connection between critical thinking skills and formal operational thought is also relatively understudied. In the study reported here, college students completed measures of…

  18. How Critical Is Critical Thinking? FACTC Focus, 2010

    ERIC Educational Resources Information Center

    Doerr, Mark, Ed.

    2010-01-01

    "FACTC Focus" is a publication of Faculty Association of Community and Technical Colleges (FACTC) with the purpose of presenting diverse views on faculty issues. Included in this issue are: (1) LOL: The Easy ROUTE TO Critical Thinking (Barbara B. Parsons); (2) Critical Thinking: We Know It When We (Don't) See It (Jared Anthony); (3) Critical…

  19. Action Research: The Development of Critical Thinking Skills

    ERIC Educational Resources Information Center

    LaPoint-O'Brien, Tammy

    2013-01-01

    Critical thinking is the focal point missed in many students' educations. Students are taught memorization with little time left for the development of critical thinking skills which allows for a deeper understanding and a richer experience. Learning to ask appropriate questions and deduce information in order to build a deeper connection to the…

  20. Critical Thinking: Why Is It so Hard to Teach?

    ERIC Educational Resources Information Center

    Willingham, Daniel T.

    2008-01-01

    After more than 20 years of lamentation, exhortation, and little improvement, writes the author, perhaps it is time to ask a fundamental question: Can critical thinking actually be taught? People who have sought to teach critical thinking have assumed that it is a skill, like riding a bicycle, and that, like other skills, once learned, it can be…

  1. A Critical Information Literacy Model: Library Leadership within the Curriculum

    ERIC Educational Resources Information Center

    Swanson, Troy

    2011-01-01

    It is a time for a new model for teaching students to find, evaluate, and use information by drawing on critical pedagogy theory in the education literature. This critical information literacy model views the information world as a dynamic place where authors create knowledge for many reasons; it seeks to understand students as information users,…

  2. A Critical Literacy Perspective for Teaching and Learning Social Studies

    ERIC Educational Resources Information Center

    Soares, Lina Bell; Wood, Karen

    2010-01-01

    In a time of increasing plurality in today's public schools, it is essential that students become critically competent citizens by examining current and historical social justice issues. The purpose of this manuscript is to provide the research, theory, and practice for teachers to help students take a critical stance as they read and respond to…

  3. Equivalent damage: A critical assessment

    NASA Technical Reports Server (NTRS)

    Laflen, J. R.; Cook, T. S.

    1982-01-01

    Concepts in equivalent damage were evaluated to determine their applicability to the life prediction of hot path components of aircraft gas turbine engines. Equivalent damage was defined as being those effects which influence the crack initiation life-time beyond the damage that is measured in uniaxial, fully-reversed sinusoidal and isothermal experiments at low homologous temperatures. Three areas of equivalent damage were examined: mean stress, cumulative damage, and multiaxiality. For each area, a literature survey was conducted to aid in selecting the most appropriate theories. Where possible, data correlations were also used in the evaluation process. A set of criteria was developed for ranking the theories in each equivalent damage regime. These criteria considered aspects of engine utilization as well as the theoretical basis and correlative ability of each theory. In addition, consideration was given to the complex nature of the loading cycle at fatigue critical locations of hot path components; this loading includes non-proportional multiaxial stressing, combined temperature and strain fluctuations, and general creep-fatigue interactions. Through applications of selected equivalent damage theories to some suitable data sets it was found that there is insufficient data to allow specific recommendations of preferred theories for general applications. A series of experiments and areas of further investigations were identified.

  4. An improved criticality alarm system

    SciTech Connect

    Tyree, W.H.; Gilpin, H.E.; Balmer, D.K.; Vennitti, D.A.

    1991-12-31

    The Rocky Flats Plant near Golden, Colorado is the primary facility for the production of plutonium components used in the US arsenal of nuclear weapons. It is operated by EG&G under contract to the US Department of Energy (DOE). There are ten production buildings on plant site with neutron based criticality alarm systems. These systems have been in operation for the past seventeen years. Changes in the interpretation of A.N.S.I. standards and DOE orders have precipitated an evaluation of detector sensitivity and placement criteria. As a result of this evaluation, improvements in detector design and calibration have improved detector sensitivity by a factor of six. Testing performed on the design defined a minimum sensitivity as required by A.N.S.I. 8.3 and provided information for saturation and survivability for a fission event of up to 1 {times} 10{sup 17} fissions in 80 microseconds. A rigorous testing and calibration program has been developed and is in place. Neutron sensitivity is certified at a nearby reactor which is traceable to N.I.S.T.. 4 refs.

  5. Automatic programming for critical applications

    NASA Technical Reports Server (NTRS)

    Loganantharaj, Raj L.

    1988-01-01

    The important phases of a software life cycle include verification and maintenance. Usually, the execution performance is an expected requirement in a software development process. Unfortunately, the verification and the maintenance of programs are the time consuming and the frustrating aspects of software engineering. The verification cannot be waived for the programs used for critical applications such as, military, space, and nuclear plants. As a consequence, synthesis of programs from specifications, an alternative way of developing correct programs, is becoming popular. The definition, or what is understood by automatic programming, has been changed with our expectations. At present, the goal of automatic programming is the automation of programming process. Specifically, it means the application of artificial intelligence to software engineering in order to define techniques and create environments that help in the creation of high level programs. The automatic programming process may be divided into two phases: the problem acquisition phase and the program synthesis phase. In the problem acquisition phase, an informal specification of the problem is transformed into an unambiguous specification while in the program synthesis phase such a specification is further transformed into a concrete, executable program.

  6. The fundamental non-critical string

    NASA Astrophysics Data System (ADS)

    Lugo, Adrián R.; Sturla, Mauricio B.

    2006-06-01

    We obtain the (super) gravity solution in arbitrary space-time dimension less than ten, that gives a low energy description of a fundamental string embedded in a non-critical vacuum, product of d-dimensional Minkowski space-time and a cigar-like geometry with scale r0. This solution, one of the few known examples of objects doubly localized, both at the origin of the transverse space as well as at the tip of the cigar, is determined by its charge Q under the Kalb-Ramond gauge field B, and presumably preserves, for even d, 2 d/2 supercharges. Moreover, we show that the solution is reliable at least in a region far away from both origins, as it is the case with the well known branes of critical string theory.

  7. Colloidal aggregation in microgravity by critical Casimir forces

    NASA Astrophysics Data System (ADS)

    Veen, Sandra; Schall, Peter; Antoniuk, Oleg; Potenza, Marco; Alaimo, Matteo; Mazzoni, Stefano; Wegdam, Gerard

    2012-02-01

    We study aggregation and crystal growth of spherical Teflon colloids in binary liquid mixtures in microgravity by the critical Casimir effect. The critical Casimir effect induces interactions between colloids due to the confinement of bulk fluctuations (density or concentration) near the critical point of liquids. The strength and range of the interaction depends on the length scale of these fluctuations which increase as one approaches the critical point. The interaction potential can thus be tuned with temperature. We follow the growth of structures in real time with Near Field Scattering. Measurements are performed in microgravity in order to study pure diffusion limited aggregation, without disturbance by sedimentation or flow.

  8. Scrutiny of Critical Thinking Concept

    ERIC Educational Resources Information Center

    Atabaki, Ali Mohammad Siahi; Keshtiaray, Narges; Yarmohammadian, Mohammad H.

    2015-01-01

    Learning critical thinking skills are the goal of educational systems so the term "critical thinking" (CT) is frequently found in educational policy documents. Despite this frequency, however, precise understandings among teachers of what CT really means do not exit. The present study is designed to answer the following question. We can…

  9. Understanding Friendship between Critical Friends

    ERIC Educational Resources Information Center

    Gibbs, Paul; Angelides, Panayiotis

    2008-01-01

    This conceptual article discusses the issue of friendship implied by the term "critical friends". Our argument relates to the generalized use of the term "friendship" and the assumptions that it may carry compared with the actuality of the roles played by critical friends. We attempt to build a more precise definition of friendship which we…

  10. Willa Cather as Drama Critic.

    ERIC Educational Resources Information Center

    Jensen, Marvin D.

    Although Willa Cather is known primarily for her short fiction and novels, she began her writing career as a literary and drama critic while still a student at the University of Nebraska. Her writing experience with the university literary periodical led her to become the drama critic for the "Nebraska State Journal," and later for the "Lincoln…

  11. Critical Thinking in Physical Education

    ERIC Educational Resources Information Center

    Humphries, Charlotte

    2014-01-01

    Changes in American education require that teachers are evaluated more often, and expectations increasingly include teaching to develop critical thinking skills. This article uses Bloom's taxonomy in describing ways physical educators can include critical thinking in their lessons, both to enhance their teaching and to meet expectations of…

  12. Critical Issues Facing School Principals

    ERIC Educational Resources Information Center

    Styron, Ronald A., Jr.; Styron, Jennifer L.

    2011-01-01

    The purpose of this study was to further extend research initially conducted in 2003 pertaining to the critical issues K-12 principals address on a daily basis. The study involved surveying school principals within the state of Mississippi to discover the critical issues they identified, the significance level of these issues, and the rationale…

  13. Critical thinking in physics education

    NASA Astrophysics Data System (ADS)

    Sadidi, Farahnaz

    2016-07-01

    We agree that training the next generation of leaders of the society, who have the ability to think critically and form a better judgment is an important goal. It is a long-standing concern of Educators and a long-term desire of teachers to establish a method in order to teach to think critically. To this end, many questions arise on three central aspects: the definition, the evaluation and the design of the course: What is Critical Thinking? How can we define Critical Thinking? How can we evaluate Critical Thinking? Therefore, we want to implement Critical Thinking in physics education. How can we teach for Critical Thinking in physics? What should the course syllabus and materials be? We present examples from classical physics and give perspectives for astro-particle physics. The main aim of this paper is to answer the questions and provide teachers with the opportunity to change their classroom to an active one, in which students are encouraged to ask questions and learn to reach a good judgment. Key words: Critical Thinking, evaluation, judgment, design of the course.

  14. A Place for Critical Literacy

    ERIC Educational Resources Information Center

    Beck, Ann S.

    2005-01-01

    The critical literacy classroom is characterized by an emphasis on students' voices and on dialogue as a tool with which students reflect on and construct meanings from texts and discourses. Is it appropriate, however, to teach critical literacy in settings such as penal institutions where student voices are deliberately discouraged and silenced?…

  15. Traditional Literacy and Critical Thinking

    ERIC Educational Resources Information Center

    Dando, Priscille

    2016-01-01

    How school librarians focus on activating critical thinking through traditional literacy development can proactively set the stage for the deep thinking that occurs in all literacy development. The critical-thinking skills students build while becoming accomplished readers and writers provide the foundation for learning in a variety of…

  16. Harnessing Critical Incidents for Learning

    ERIC Educational Resources Information Center

    Patahuddin, Sitti Maesuri; Lowrie, Tom

    2015-01-01

    A critical incident is a situation or event that holds significance for learning, both for the students and teachers. This paper presents four examples of critical incidents from a Year 7 teacher's lesson excerpts in Indonesia involving teaching of fractions, to show how they shaped classroom situation, brought forward elements of conflict, and…

  17. Quantifying Learning in Critical Thinking

    ERIC Educational Resources Information Center

    Fliegel, Richard; Holland, John

    2013-01-01

    This article describes a three-year study assessing change in critical thinking demonstrated in essays written for regular class assignments. A rubric was designed and scorers trained to assess critical thinking holistically without knowledge of the writing prompt or author's status. The longitudinal improvement in scores earned by freshmen…

  18. Cabbage Worms and Critical Thinking.

    ERIC Educational Resources Information Center

    Braswell, Patricia

    1993-01-01

    Argues that an approach to composition instruction that emphasizes critical thinking skills produces a more analytical writer. Describes a school project that examined research on critical thinking, implemented changes in the teaching of thinking and composition, and assessed student learning. (HB)

  19. Critical Pedagogy in Health Education

    ERIC Educational Resources Information Center

    Matthews, Catherine

    2014-01-01

    Objective: This review investigated how the three-phase model of critical pedagogy, based on the writings of Paulo Freire, can be put into practice in health education. Design: The study considers literature related to the fields of health education, health promotion and critical pedagogy. Setting: The study is a scholarly review completed as part…

  20. Teaching Students to Think Critically

    ERIC Educational Resources Information Center

    Black, Susan

    2005-01-01

    In this article, the author stresses that teachers need to teach their students to think critically and to reason their way. One prerequisite for teaching critical thinking is a classroom climate of high expectations, teacher warmth and encouragement, and pleasant physical surroundings. Schools should see to it that students become progressively…

  1. Education Studies: Issues & Critical Perspectives

    ERIC Educational Resources Information Center

    Kassem, Derek; Mufti, Emmanuel; Robinson, John

    2006-01-01

    This major text for Education Studies students provides a critical account of key issues in education today. The text features: (1) A critical analysis of key issues in Education Studies to encourage students' thinking about education in the broadest terms; (2) Themed sections with introductions to link the issues discussed in each chapter; (3)…

  2. Critical Thinking: Schemata vs. Skills.

    ERIC Educational Resources Information Center

    Brandhorst, Allan R.

    1989-01-01

    Refutes the idea that critical thinking is not a skill by analyzing it from the phenomenological perspective of Edmund Husserl, and from the hermeneutic perspective of Martin Heidegger. Develops the thesis that critical thinking is a restructuring of schemata. Addresses the problem of attention or student engagement. (LS)

  3. Broadband Criticality of Human Brain Network Synchronization

    PubMed Central

    Kitzbichler, Manfred G.; Smith, Marie L.; Christensen, Søren R.; Bullmore, Ed

    2009-01-01

    Self-organized criticality is an attractive model for human brain dynamics, but there has been little direct evidence for its existence in large-scale systems measured by neuroimaging. In general, critical systems are associated with fractal or power law scaling, long-range correlations in space and time, and rapid reconfiguration in response to external inputs. Here, we consider two measures of phase synchronization: the phase-lock interval, or duration of coupling between a pair of (neurophysiological) processes, and the lability of global synchronization of a (brain functional) network. Using computational simulations of two mechanistically distinct systems displaying complex dynamics, the Ising model and the Kuramoto model, we show that both synchronization metrics have power law probability distributions specifically when these systems are in a critical state. We then demonstrate power law scaling of both pairwise and global synchronization metrics in functional MRI and magnetoencephalographic data recorded from normal volunteers under resting conditions. These results strongly suggest that human brain functional systems exist in an endogenous state of dynamical criticality, characterized by a greater than random probability of both prolonged periods of phase-locking and occurrence of large rapid changes in the state of global synchronization, analogous to the neuronal “avalanches” previously described in cellular systems. Moreover, evidence for critical dynamics was identified consistently in neurophysiological systems operating at frequency intervals ranging from 0.05–0.11 to 62.5–125 Hz, confirming that criticality is a property of human brain functional network organization at all frequency intervals in the brain's physiological bandwidth. PMID:19300473

  4. Hope: critical therapy.

    PubMed

    Pavelis, K W

    1997-01-01

    According to a recent Time magazine article, a 1995 study at Dartmouth-Hitchcock Medical Center found that one of the best predictors of survival among 232 heart-surgery patients was the degree to which the patients said they drew comfort and strength from religious faith. Those who did not had more than three times the death rate of those who did (June 24, 1996, pp. 59-68) Likewise, according to the article, numerous studies have found lower rates of depression among the religiously committed.The article goes on to state that patients with chronic health problems are failing to find relief in a doctor's office, and the increasing use of high-tech scans and tests of modern medicine leave patients feeling uncared for and alienated.Dr. Herbert Benson, President of the Mind/Body Medical Institute at Boston's Deaconess Hospital and Harvard Medical School, in his book, Timeless Healing, demonstrated the role of meditation and spirituality in patients battling chronic illnesses. A 5-year study found that those who claimed to feel the intimate presence of a higher power had better health and more rapid recoveries.As clinicians, we were not trained to recognize or teach our patients how to act on the role of faith and hope in healing. However, as researchers, we cannot dismiss the possibility that there is a definite relationship.The following commentary is offered to you as food for thought. Today, as we continue to seek ways to reduce health care costs while still providing effective methods of treating illness, we must not rule out factors such as faith and hope in meeting our ultimate goal of healing the sick.

  5. Hope: critical therapy.

    PubMed

    Pavelis, K W

    1997-01-01

    According to a recent Time magazine article, a 1995 study at Dartmouth-Hitchcock Medical Center found that one of the best predictors of survival among 232 heart-surgery patients was the degree to which the patients said they drew comfort and strength from religious faith. Those who did not had more than three times the death rate of those who did (June 24, 1996, pp. 59-68) Likewise, according to the article, numerous studies have found lower rates of depression among the religiously committed.The article goes on to state that patients with chronic health problems are failing to find relief in a doctor's office, and the increasing use of high-tech scans and tests of modern medicine leave patients feeling uncared for and alienated.Dr. Herbert Benson, President of the Mind/Body Medical Institute at Boston's Deaconess Hospital and Harvard Medical School, in his book, Timeless Healing, demonstrated the role of meditation and spirituality in patients battling chronic illnesses. A 5-year study found that those who claimed to feel the intimate presence of a higher power had better health and more rapid recoveries.As clinicians, we were not trained to recognize or teach our patients how to act on the role of faith and hope in healing. However, as researchers, we cannot dismiss the possibility that there is a definite relationship.The following commentary is offered to you as food for thought. Today, as we continue to seek ways to reduce health care costs while still providing effective methods of treating illness, we must not rule out factors such as faith and hope in meeting our ultimate goal of healing the sick. PMID:24572824

  6. EEW Implementation into Critical Infrastructures

    NASA Astrophysics Data System (ADS)

    Zulfikar, Can; Pinar, Ali

    2016-04-01

    In FP7 MARsite project WP9, the integration algorithm of existing strong motion networks with the critical infrastructures strong motion networks have been studied. In Istanbul, the existing Istanbul Earthquake Early Warning (IEEW) strong motion network consists of 15 stations including 10 on land and 5 ocean bottom stations. The system provides continuous online data and earthquake early warning alert depending on the exceedance of the threshold levels in ground motion acceleration in certain number of station within the certain time interval. The data transmission is provided through the fiber optic cable and satellite line alternatively. The early warning alert is transmitted to the critical infrastructures of Istanbul Natural Gas distribution line and Marmaray Tube Tunnel line in order to activate the local strong motion networks for the automatic shut-off mechanism. Istanbul Natural Gas distribution line has 1.800km steel and 15.200km polyethylene in total 18.000km gas pipeline in Istanbul. There are in total 750 district regulators in the city where the gas pressure is reduced from 20bar to 4bar and from there the gas is transmitted with polyethylene lines to service boxes. Currently, Istanbul Natural Gas Distribution Company (IGDAS) has its own strong motion network with 110 strong motion stations installed at the 110 of 750 district regulators. Once the IGDAS strong motion network is activated by the IEEW network, depending on the exceedance of the ground motion parameters threshold levels the gas flow is stopped at the district regulators. Other than the Earthquake Early Warning operation in IGDAS strong motion network, having the calculated ground motion parameters in the network provides damage maps for the buildings and natural gas pipeline network. The Marmaray Tube Tunnel connects the Europe and Asian sides of Istanbul City by a rail line. The tunnel is 1.4km length and consists of 13segments. There is strong motion monitoring network in the tunnel

  7. Enacting Critical Literacy in English Classrooms: How a Teacher Learning Community Supported Critical Inquiry

    ERIC Educational Resources Information Center

    Riley, Kathleen

    2015-01-01

    In a time of increased standardization and top-down reform, teachers with democratic and social justice-oriented perspectives must work to create classroom spaces that value student voice and position them as knowledge holders. This article draws on a critical literacy framework to analyze the case study of one teacher working within a teacher…

  8. Critical Incident Nursing Management Using Human Patient Simulators.

    ERIC Educational Resources Information Center

    Nehring, Wendy M.; Lahsley, Felissa R.; Ellis, Wayne E.

    2002-01-01

    Human patient simulators are computerized mannequins that present patient scenarios in which nursing students learn to assess critical health incidents. Their use involves faculty time and commitment, maintenance and upgrading investment, and careful scenario preparation. (Contains 20 references.) (SK)

  9. Criticality and Cancer Dormancy

    NASA Astrophysics Data System (ADS)

    Wu, Amy; Liao, David; Kirlin, Vladimir; Tamita, Corina; Levin, Simon; Sturm, James; Austin, Robert

    The presence of driver mutations and subsequent clonal expansion by Darwinian evolution does not explain dormancy and re-emergence of cancer from a community of cancer and stromal cells. Dormancy appears to be a collective property of multiple cell communities including non-cancerous cells. At the simplest level, we view cancer cells interacting with stromal cells via complex, non-linear population dynamics, dynamics which can lead to very non-intuitive but perhaps deterministic and understandable progression dynamics of cancer. We explore here the dynamics of stromal-cancer cell populations in the presence of a chemotherapy drug gradient to determine to what extent the time-dependence of the populations can be quantitively understood in spite of the underlying complexity of the individual agents. The surprising result is that a basic understanding, in a quantitive and predictive manner, can be achieved. It will be intriguing to move to predictive drug dosages, the population dynamics presented here provide a model system for the clinic.

  10. Teaching and evaluating critical thinking in respiratory care.

    PubMed

    Mishoe, Shelley C; Hernlen, Kitty

    2005-09-01

    The capacity to perform critical thinking in respiratory care may be enhanced through awareness and education to improve skills, abilities, and opportunities. The essential skills for critical thinking in respiratory care include prioritizing, anticipating, troubleshooting, communicating, negotiating, decision making, and reflecting. In addition to these skills, critical thinkers exhibit certain characteristics such as critical evaluation, judgment,insight, motivation, and lifelong learning. The teaching of critical thinking may be accomplished though problem-based learning using an evidenced-based approach to solve clinical problems similar to those encountered in professional practice. Other traditional strategies such as discussion, debate, case study, and case presentations can be used. Web-based curriculum and technologic advances have created opportunities such as bulletin boards, real-time chats, and interactive media tools that can incorporate critical thinking. Many concerns and controversies surround the assessment of critical thinking, and individuals who administer critical thinking tests must be aware of the strengths and limitations of these assessment tools, as well as their relevance to the workplace. The foundational works reported in this article summarize the current status of assessment of critical thinking and can stimulate further investigation and application of the skills, characteristics, educational strategies, and measurement of critical thinking in respiratory care. PMID:16168915

  11. Teaching and evaluating critical thinking in respiratory care.

    PubMed

    Mishoe, Shelley C; Hernlen, Kitty

    2005-09-01

    The capacity to perform critical thinking in respiratory care may be enhanced through awareness and education to improve skills, abilities, and opportunities. The essential skills for critical thinking in respiratory care include prioritizing, anticipating, troubleshooting, communicating, negotiating, decision making, and reflecting. In addition to these skills, critical thinkers exhibit certain characteristics such as critical evaluation, judgment,insight, motivation, and lifelong learning. The teaching of critical thinking may be accomplished though problem-based learning using an evidenced-based approach to solve clinical problems similar to those encountered in professional practice. Other traditional strategies such as discussion, debate, case study, and case presentations can be used. Web-based curriculum and technologic advances have created opportunities such as bulletin boards, real-time chats, and interactive media tools that can incorporate critical thinking. Many concerns and controversies surround the assessment of critical thinking, and individuals who administer critical thinking tests must be aware of the strengths and limitations of these assessment tools, as well as their relevance to the workplace. The foundational works reported in this article summarize the current status of assessment of critical thinking and can stimulate further investigation and application of the skills, characteristics, educational strategies, and measurement of critical thinking in respiratory care.

  12. [Plasma aminogram in critical patients].

    PubMed

    Martínez, M J; Giráldez, J

    1993-02-01

    This study of the plasma aminogram was done on 35 patients with a moderate to high level of stress and/or sepsis. For the criteria of illness, the SAPS (Simplified Acute Physiological Score) was used on their admission to the intensive Care Unit, and the diagnosis of sepsis was established according to the criteria of Jacobs and Boone. The stress level was calculated according to Bistrian. The plasma aminogram was determined with High Resolution Liquid Chromatography. The plasma samples were taken while nutrient units containing what is considered a standard solution of amino acids were infused. The eight essential amino acids (EAA) and 10 non-essential were quantified. The ratio of ramified to aromatic amino acids (RAA/AAA) was calculated by Fisher's criteria. An increase in AAA (phenylalanine, p < 0.001, and tyrosine, NS) and sulphur containing amino acids (methionine, p < 0.001) was found. The RAA were within normal ranges (valine) or increased (leucine, p < 0.001 and isoleucine, p < 0.001). The RAA/AAA ratio was reduced, p < 0.0001. Glycine was increased, p < 0.0001 and alanine reduced, p < 0.05. Glutamine and glutamic acid were reduced, p < 0.0001 and p < 0.01 as was arginine, p < 0.001. No difference was found in the total concentration of AA. The results confirm the standard plasma aminogram described in situations of metabolic stress and/or sepsis.

  13. Critical appraisal of clinical guidelines.

    PubMed

    Netsch, Debra S; Kluesner, Jean A

    2010-01-01

    Utilization of clinical guidelines is gaining in popularity due to their significant impact on clinical practice. While a plethora of guidelines exist, many are lacking in quality, based on current critical appraisal standards. It then becomes necessary for the end users of the guidelines to adopt or develop those that are deemed adequate for implementation. This often requires that users possess critical appraisal skills as they become proficient in discerning between guidelines of varying quality. This article provides direction and tools to support the critical appraisal process in the adoption of clinical guidelines. PMID:20838314

  14. Critical behavior of gravitating sphalerons

    NASA Astrophysics Data System (ADS)

    Millward, R. Steven; Hirschmann, Eric W.

    2003-07-01

    We examine the gravitational collapse of sphaleron type configurations in the Einstein-Yang-Mills-Higgs theory. Working in spherical symmetry, we investigate the critical behavior in this model. We provide evidence that for various initial configurations, there can be three different critical transitions between possible end states with different critical solutions sitting on the threshold between these outcomes. In addition, we show that within the dispersive and black hole regimes there are new possible end states: namely, a stable, regular sphaleron and a stable, hairy black hole.

  15. Time for Reading?

    ERIC Educational Resources Information Center

    Fowler, William R.

    1989-01-01

    Reading for pleasure and enlightenment is a critical, and endangered, element in a well-informed citizenry. As a basis for intellectual growth, reading is threatened by media misuse and lack of encouragement of recreational reading. Solutions include emphasis on integrated skills, improved time allocation, and cooperation among parents, teachers,…

  16. The critical velocity in swimming.

    PubMed

    di Prampero, Pietro E; Dekerle, Jeanne; Capelli, Carlo; Zamparo, Paola

    2008-01-01

    In supra-maximal exercise to exhaustion, the critical velocity (cv) is conventionally calculated from the slope of the distance (d) versus time (t) relationship: d = I + St. I is assumed to be the distance covered at the expense of the anaerobic capacity, S the speed maintained on the basis of the subject's maximal O(2) uptake (VO2max) This approach is based on two assumptions: (1) the energy cost of locomotion per unit distance (C) is constant and (2) VO2max is attained at the onset of exercise. Here we show that cv and the anaerobic distance (d (anaer)) can be calculated also in swimming, where C increases with the velocity, provided that VO2max its on-response, and the C versus v relationship are known. d (anaer) and cv were calculated from published data on maximal swims for the four strokes over 45.7, 91.4 and 182.9 m, on 20 elite male swimmers (18.9 +/- 0.9 years, 75.9 +/- 6.4 kg), whose VO2max and C versus speed relationship were determined, and compared to I and S obtained from the conventional approach. cv was lower than S (4, 16, 7 and 11% in butterfly, backstroke, breaststroke and front crawl) and I (=11.6 m on average in the four strokes) was lower than d (anaer). The latter increased with the distance: average, for all strokes: 38.1, 60.6 and 81.3 m over 45.7, 91.4 and 182.9 m. It is concluded that the d versus t relationship should be utilised with some caution when evaluating performance in swimmers.

  17. Surveys explore critical governance relationship.

    PubMed

    Grant, M K

    1987-01-01

    The transition in religious-sponsored health care from a ministry of direct service to one of governance has generated serious and penetrating questions, analyses, and retrenchment. Emphasis on and demand for value-laden leadership development programs are growing at the same time that sponsoring groups are becoming more actively involved in the governance and oversight of their corporate ministries. Two recent Catholic Health Association (CHA) studies focused on the critical governance relationship between the sponsoring group and its incorporated ministries. The first study asked religious institutes and dioceses that were sponsors of CHA member health care freestanding facilities and systems to describe their current governance structure. The second study represented an initial attempt to identify qualitative components of effective governance or sponsorship and asked 19 major superiors and system chief executive officers (CEOs) to characterize an ideal relationship between sponsor and ministry. The studies' findings included the following: In freestanding facilities, lay-religious governing boards have all but replaced the all-sponsor and all-lay advisory boards of the past. Trustee orientation, development, and evaluation were not equally stressed in the three groups surveyed, with trustee evaluation programs lagging behind in all three. Major superiors and CEOs had remarkably similar expectations relating to accountability for mission, relationships between sponsor and corporation, communication, and leadership development. Both major superiors and CEOs looked for greater collaboration in defining roles, translating mission into "business plan", and developing formation programs for leadership. Major superiors' emphasized simplicity of life-style, whereas the CEOs stressed stable commitment to corporate ministry.

  18. The critical velocity in swimming.

    PubMed

    di Prampero, Pietro E; Dekerle, Jeanne; Capelli, Carlo; Zamparo, Paola

    2008-01-01

    In supra-maximal exercise to exhaustion, the critical velocity (cv) is conventionally calculated from the slope of the distance (d) versus time (t) relationship: d = I + St. I is assumed to be the distance covered at the expense of the anaerobic capacity, S the speed maintained on the basis of the subject's maximal O(2) uptake (VO2max) This approach is based on two assumptions: (1) the energy cost of locomotion per unit distance (C) is constant and (2) VO2max is attained at the onset of exercise. Here we show that cv and the anaerobic distance (d (anaer)) can be calculated also in swimming, where C increases with the velocity, provided that VO2max its on-response, and the C versus v relationship are known. d (anaer) and cv were calculated from published data on maximal swims for the four strokes over 45.7, 91.4 and 182.9 m, on 20 elite male swimmers (18.9 +/- 0.9 years, 75.9 +/- 6.4 kg), whose VO2max and C versus speed relationship were determined, and compared to I and S obtained from the conventional approach. cv was lower than S (4, 16, 7 and 11% in butterfly, backstroke, breaststroke and front crawl) and I (=11.6 m on average in the four strokes) was lower than d (anaer). The latter increased with the distance: average, for all strokes: 38.1, 60.6 and 81.3 m over 45.7, 91.4 and 182.9 m. It is concluded that the d versus t relationship should be utilised with some caution when evaluating performance in swimmers. PMID:17901978

  19. TUM Critical Zone Observatory, Germany

    NASA Astrophysics Data System (ADS)

    Völkel, Jörg; Eden, Marie

    2014-05-01

    Founded 2011 the TUM Critical Zone Observatory run by the Technische Universität München and partners abroad is the first CZO within Germany. TUM CZO is both, a scientific as well as an education project. It is a watershed based observatory, but moving behind this focus. In fact, two mountainous areas are integrated: (1) The Ammer Catchment area as an alpine and pre alpine research area in the northern limestone Alps and forelands south of Munich; (2) the Otter Creek Catchment in the Bavarian Forest with a crystalline setting (Granite, Gneiss) as a mid mountainous area near Regensburg; and partly the mountainous Bavarian Forest National Park. The Ammer Catchment is a high energy system as well as a sensitive climate system with past glacial elements. The lithology shows mostly carbonates from Tertiary and Mesozoic times (e.g. Flysch). Source-to-sink processes are characteristic for the Ammer Catchment down to the last glacial Ammer Lake as the regional erosion and deposition base. The consideration of distal depositional environments, the integration of upstream and downstream landscape effects are characteristic for the Ammer Catchment as well. Long term datasets exist in many regards. The Otter Creek catchment area is developed in a granitic environment, rich in saprolites. As a mid mountainous catchment the energy system is facing lower stage. Hence, it is ideal comparing both of them. Both TUM CZO Catchments: The selected catchments capture the depositional environment. Both catchment areas include historical impacts and rapid land use change. Crosscutting themes across both sites are inbuilt. Questions of ability to capture such gradients along climosequence, chronosequence, anthroposequence are essential.

  20. HELIOS Critical Design Review: Reliability

    NASA Technical Reports Server (NTRS)

    Benoehr, H. C.; Herholz, J.; Prem, H.; Mann, D.; Reichert, L.; Rupp, W.; Campbell, D.; Boettger, H.; Zerwes, G.; Kurvin, C.

    1972-01-01

    This paper presents Helios Critical Design Review Reliability form October 16-20, 1972. The topics include: 1) Reliability Requirement; 2) Reliability Apportionment; 3) Failure Rates; 4) Reliability Assessment; 5) Reliability Block Diagram; and 5) Reliability Information Sheet.

  1. The critics return to flight.

    PubMed

    Jones, Thomas D

    2005-08-01

    A former astronaut justifies human space exploration and provides a rebuttal to criticism of continued exploration. The discussion includes examples of skeptics' arguments and examples of NASA achievements that have had direct economic and social impacts on the United States.

  2. Coping with criticism and praise.

    PubMed

    Esdale, Lynn; Jahoda, Andrew; Pert, Carol

    2015-05-01

    Through experiencing stigma and discrimination, people with intellectual disability may become more sensitive to criticism from others and be less likely to believe praise. This study compared how people with and without intellectual disability viewed praise and criticism, using a vignette task developed for the study. Participants were asked to imagine someone saying something praiseworthy or critical and were then asked about their emotions, beliefs, and thoughts. People with intellectual disability were more likely to believe and be distressed by criticism. Contrary to predictions, this group were also more likely to believe praise and experience positive affect. The results suggest that the self-perceptions of people with intellectual disabilities is more dynamic and reliant on the views of others.

  3. Critical Barriers to Science Learning

    ERIC Educational Resources Information Center

    Hawkins, David

    1978-01-01

    The author illustrates and discusses some critical barrier phenomena, such as the optics of mirrors and heat and cold, which most people have difficulty extending beyond an everyday understanding. (Author/MA)

  4. Critical scattering in polymer melts

    SciTech Connect

    Bates, F.S.; Hartney, M.A.; Wignall, G.D.

    1985-10-01

    Critical phenomena in two classes of polymer melts have been examined by small-angle neutron scattering (SANS); single component block polymers which undergo an order-disorder phase transition, and binary polymer mixtures which exhibit classical liquid-liquid phase separation behavior. A model set of 1,4-polybutadiene-1,2-polybutadiene diblock copolymers containing perdeuterated 1,4-polybutadiene blocks were investigated by SANS in the disordered state. The SANS spectra exhibit a peak in the scattering intensity which diverges at the ordering transition, in close agreement with mean-field theory. Binary blends of perdeuterated and protonated 1,4-polybutadiene homopolymers have been found to form regular solutions characterized by an upper critical solution temperature (UCST). Near the critical point, these mixtures exhibit classical critical scattering as measured by SANS. The second set of results raises serious questions regarding the widely held assumption that deuterated and protonated polymers form ideal mixtures.

  5. Critical Theory in Historical Perspective.

    ERIC Educational Resources Information Center

    Hardt, Hanno

    1986-01-01

    Reviews two books by Martin Jay on the intellectual history of Western Marxism and critical theory "in exile" that detail the complex foundations of an ideological critique of culture and society and evaluates their meaning for communications scholarship. (JD)

  6. Nonadditivity of critical Casimir forces.

    PubMed

    Paladugu, Sathyanarayana; Callegari, Agnese; Tuna, Yazgan; Barth, Lukas; Dietrich, Siegfried; Gambassi, Andrea; Volpe, Giovanni

    2016-01-01

    In soft condensed matter physics, effective interactions often emerge due to the spatial confinement of fluctuating fields. For instance, microscopic particles dissolved in a binary liquid mixture are subject to critical Casimir forces whenever their surfaces confine the thermal fluctuations of the order parameter of the solvent close to its critical demixing point. These forces are theoretically predicted to be nonadditive on the scale set by the bulk correlation length of the fluctuations. Here we provide direct experimental evidence of this fact by reporting the measurement of the associated many-body forces. We consider three colloidal particles in optical traps and observe that the critical Casimir force exerted on one of them by the other two differs from the sum of the forces they exert separately. This three-body effect depends sensitively on the distance from the critical point and on the chemical functionalisation of the colloid surfaces. PMID:27097797

  7. Psychoanalytic Criticism and Teaching Shakespeare.

    ERIC Educational Resources Information Center

    Wheeler, Richard P.

    1987-01-01

    Presents a brief overview of previous psychoanalytically based theories of Shakespeare's plays, particularly "Hamlet," and defends the notion of introducing undergraduates to psychoanalytically based criticism because of the insights it may give students into their own lives. (JC)

  8. Television Criticism: A Multifarious Approach.

    ERIC Educational Resources Information Center

    Oseguera, A. Anthony

    Recognizing the need for a multifarious approach to television, this paper provides the reader with the following multidimensional approaches to television criticism: rhetorical, dramatic, literary, cinematic, content analysis, myth, linguistics, semiotics, phenomenalism, phenomenology, interpersonal communication, public relations, image,…

  9. Nonadditivity of critical Casimir forces

    PubMed Central

    Paladugu, Sathyanarayana; Callegari, Agnese; Tuna, Yazgan; Barth, Lukas; Dietrich, Siegfried; Gambassi, Andrea; Volpe, Giovanni

    2016-01-01

    In soft condensed matter physics, effective interactions often emerge due to the spatial confinement of fluctuating fields. For instance, microscopic particles dissolved in a binary liquid mixture are subject to critical Casimir forces whenever their surfaces confine the thermal fluctuations of the order parameter of the solvent close to its critical demixing point. These forces are theoretically predicted to be nonadditive on the scale set by the bulk correlation length of the fluctuations. Here we provide direct experimental evidence of this fact by reporting the measurement of the associated many-body forces. We consider three colloidal particles in optical traps and observe that the critical Casimir force exerted on one of them by the other two differs from the sum of the forces they exert separately. This three-body effect depends sensitively on the distance from the critical point and on the chemical functionalisation of the colloid surfaces. PMID:27097797

  10. Interpretative reports and critical values.

    PubMed

    Piva, Elisa; Plebani, Mario

    2009-06-01

    In the clinical laboratory to allow an effective testing process, post-analytical activity can have two goals in trying to improve patient safety: result interpretation and communication of critical values. Both are important issues, and their success requires a cooperative effort. Misinterpretation of laboratory test results or ineffectiveness in their notification can lead to diagnostic errors or errors in identifying patient critical conditions. With the awareness that the incorrect interpretation of tests and the breakdown in the communication of critical values are preventable errors, laboratorians should make every effort to prevent the types of errors that potentially harm patients. In order to improve the reliability of laboratories, we attempt to explain how interpretative reporting and automated notification of critical values can be used to reduce errors. Clinical laboratories can therefore work to improve clinical effectiveness, without forgetting that everything should be designed to provide the best outcomes for patients.

  11. Identity Politics and Critical Pedagogy.

    ERIC Educational Resources Information Center

    Bromley, Hank

    1989-01-01

    This essay investigates what identity politics may have to contribute to the reformation of Marxist theories of education through considering how it would theorize the practice of explicitly critical pedagogy. (IAH)

  12. Autoclave nuclear criticality safety analysis

    SciTech Connect

    D`Aquila, D.M.; Tayloe, R.W. Jr.

    1991-12-31

    Steam-heated autoclaves are used in gaseous diffusion uranium enrichment plants to heat large cylinders of UF{sub 6}. Nuclear criticality safety for these autoclaves is evaluated. To enhance criticality safety, systems are incorporated into the design of autoclaves to limit the amount of water present. These safety systems also increase the likelihood that any UF{sub 6} inadvertently released from a cylinder into an autoclave is not released to the environment. Up to 140 pounds of water can be held up in large autoclaves. This mass of water is sufficient to support a nuclear criticality when optimally combined with 125 pounds of UF{sub 6} enriched to 5 percent U{sup 235}. However, water in autoclaves is widely dispersed as condensed droplets and vapor, and is extremely unlikely to form a critical configuration with released UF{sub 6}.

  13. Quantum clock: A critical discussion on spacetime

    NASA Astrophysics Data System (ADS)

    Burderi, Luciano; Di Salvo, Tiziana; Iaria, Rosario

    2016-03-01

    We critically discuss the measure of very short time intervals. By means of a Gedankenexperiment, we describe an ideal clock based on the occurrence of completely random events. Many previous thought experiments have suggested fundamental Planck-scale limits on measurements of distance and time. Here we present a new type of thought experiment, based on a different type of clock, that provide further support for the existence of such limits. We show that the minimum time interval Δ t that this clock can measure scales as the inverse of its size Δ r . This implies an uncertainty relation between space and time: Δ r Δ t >G ℏ/c4, where G , ℏ, and c are the gravitational constant, the reduced Planck constant, and the speed of light, respectively. We outline and briefly discuss the implications of this uncertainty conjecture.

  14. Critical health literacy: a review and critical analysis.

    PubMed

    Chinn, Deborah

    2011-07-01

    Though there has been a considerable expansion of interest in the health literacy concept worldwide, there has also been criticism that this concept has been poorly defined, that it stretches the idea of "literacy" to an indefensible extent and more specifically, that it adds little to the existing concerns and intervention approaches of the better established discipline of health promotion. This paper takes as a starting point the expanded model of health literacy advanced by Nutbeam (2000) and addresses these concerns by interrogating the concept of "critical health literacy" in order to draw conclusions about its utility for advancing the health of individuals and communities. The constituent domains of critical health literacy are identified; namely information appraisal, understanding the social determinants of health, and collective action, and as far as possible each are clearly delineated, with links to related concepts made explicit. The paper concludes that an appreciation of work undertaken in a range of different disciplines, such as media studies, medical sociology, and evidence-based medicine can enhance our understanding of the critical health literacy construct and help us understand its usefulness as a social asset which helps individuals towards a critical engagement with health information. There is some evidence that aspects of critical health literacy have indeed been found to be a resource for better health outcomes, but more research is needed in this area, both to develop quantitative and qualitative approaches to evaluating health literacy skills, and to offer convincing evidence that investment in programmes designed to enhance critical health literacy are worthwhile.

  15. Solid-gas critical flow

    SciTech Connect

    Gidaspow, D.; Syamlal, M.

    1985-01-01

    Maximum solid-gas transport rates have been computed using several hydrodynamic models. In the limit of zero gas density, the critical velocity equals the square root of a compressibility modulus of the powder divided by its density. Compressibility waves move with this velocity through the powder. Part II of this paper deals with homogeneous critical powder flow for which a useful expression for maximum flow has been derived and compared to an experiment from the literature.

  16. Lecture notes for criticality safety

    SciTech Connect

    Fullwood, R.

    1992-03-01

    These lecture notes for criticality safety are prepared for the training of Department of Energy supervisory, project management, and administrative staff. Technical training and basic mathematics are assumed. The notes are designed for a two-day course, taught by two lecturers. Video tapes may be used at the options of the instructors. The notes provide all the materials that are necessary but outside reading will assist in the fullest understanding. The course begins with a nuclear physics overview. The reader is led from the macroscopic world into the microscopic world of atoms and the elementary particles that constitute atoms. The particles, their masses and sizes and properties associated with radioactive decay and fission are introduced along with Einstein's mass-energy equivalence. Radioactive decay, nuclear reactions, radiation penetration, shielding and health-effects are discussed to understand protection in case of a criticality accident. Fission, the fission products, particles and energy released are presented to appreciate the dangers of criticality. Nuclear cross sections are introduced to understand the effectiveness of slow neutrons to produce fission. Chain reactors are presented as an economy; effective use of the neutrons from fission leads to more fission resulting in a power reactor or a criticality excursion. The six-factor formula is presented for managing the neutron budget. This leads to concepts of material and geometric buckling which are used in simple calculations to assure safety from criticality. Experimental measurements and computer code calculations of criticality are discussed. To emphasize the reality, historical criticality accidents are presented in a table with major ones discussed to provide lessons-learned. Finally, standards, NRC guides and regulations, and DOE orders relating to criticality protection are presented.

  17. Lecture notes for criticality safety

    SciTech Connect

    Fullwood, R.

    1992-03-01

    These lecture notes for criticality safety are prepared for the training of Department of Energy supervisory, project management, and administrative staff. Technical training and basic mathematics are assumed. The notes are designed for a two-day course, taught by two lecturers. Video tapes may be used at the options of the instructors. The notes provide all the materials that are necessary but outside reading will assist in the fullest understanding. The course begins with a nuclear physics overview. The reader is led from the macroscopic world into the microscopic world of atoms and the elementary particles that constitute atoms. The particles, their masses and sizes and properties associated with radioactive decay and fission are introduced along with Einstein`s mass-energy equivalence. Radioactive decay, nuclear reactions, radiation penetration, shielding and health-effects are discussed to understand protection in case of a criticality accident. Fission, the fission products, particles and energy released are presented to appreciate the dangers of criticality. Nuclear cross sections are introduced to understand the effectiveness of slow neutrons to produce fission. Chain reactors are presented as an economy; effective use of the neutrons from fission leads to more fission resulting in a power reactor or a criticality excursion. The six-factor formula is presented for managing the neutron budget. This leads to concepts of material and geometric buckling which are used in simple calculations to assure safety from criticality. Experimental measurements and computer code calculations of criticality are discussed. To emphasize the reality, historical criticality accidents are presented in a table with major ones discussed to provide lessons-learned. Finally, standards, NRC guides and regulations, and DOE orders relating to criticality protection are presented.

  18. Training in critical care echocardiography

    PubMed Central

    2011-01-01

    Echocardiography is useful for the diagnosis and management of hemodynamic failure in the intensive care unit so that competence in some elements of echocardiography is a core skill of the critical care specialist. An important issue is how to provide training to intensivists so that they are competent in the field. This article will review issues related to training in critical care echocardiography. PMID:21906268

  19. Brane worlds in critical gravity

    NASA Astrophysics Data System (ADS)

    Chen, Feng-Wei; Liu, Yu-Xiao; Zhong, Yuan; Wang, Yong-Qiang; Wu, Shao-Feng

    2013-11-01

    Recently, Lü and Pope proposed critical gravities in [Phys. Rev. Lett. 106, 181302 (2011)]. In this paper we construct analytic brane solutions in critical gravity with matter. The Gibbons-Hawking surface term and junction condition are investigated, and the thin and thick brane solutions are obtained. All these branes are embedded in five-dimensional anti-de Sitter spacetimes. Our solutions are stable against scalar perturbations, and the zero modes of scalar perturbations cannot be localized on the branes.

  20. Critical realism and the dialectic.

    PubMed

    Roberts, J M

    2001-12-01

    A prominent strand within both sociological and social theory has been concerned to develop a 'systems approach' with which to explore social life. One of the most original contributions to a systems approach has arisen within critical realism. In particular critical realism demonstrates that it is possible to abstract the causal powers of different objects of analysis to examine their interaction within concrete and contingent 'open systems'. The recent dialectical turn of critical realism develops this systems approach in a much more rigorous manner. However, in this paper I argue that the (dialectical) critical realist mode of abstraction ultimately fails to embed concepts and categories internally within the specific ideological and historical forms of social relations. Or rather, critical realists do not seek to develop concepts that reflect the self-movement of a historical and contradictory essence. This self-movement is what I prefer to call a 'system'. Consequently critical realists are led to separate method from system in theory construction and such a separation leads to a problematic dualist mode of theorizing. I make these observations from a Hegelian-Marxist position. PMID:11853063