WorldWideScience

Sample records for handoff transition time

  1. Warm Handoffs: a Novel Strategy to Improve End-of-Rotation Care Transitions.

    Science.gov (United States)

    Saag, Harry S; Chen, Jingjing; Denson, Joshua L; Jones, Simon; Horwitz, Leora; Cocks, Patrick M

    2018-01-01

    Hospitalized medical patients undergoing transition of care by house staff teams at the end of a ward rotation are associated with an increased risk of mortality, yet best practices surrounding this transition are lacking. To assess the impact of a warm handoff protocol for end-of-rotation care transitions. A large, university-based internal medicine residency using three different training sites. PGY-2 and PGY-3 internal medicine residents. Implementation of a warm handoff protocol whereby the incoming and outgoing residents meet at the hospital to sign out in-person and jointly round at the bedside on sicker patients using a checklist. An eight-question survey completed by 60 of 99 eligible residents demonstrated that 85% of residents perceived warm handoffs to be safer for patients (p rotation (p rotation care transitions. Additional studies analyzing patient outcomes will be needed to assess the impact of this strategy.

  2. "Ms. B changes doctors": using a comic and patient transition packet to engineer patient-oriented clinic handoffs (EPOCH).

    Science.gov (United States)

    Pincavage, Amber T; Lee, Wei Wei; Venable, Laura Ruth; Prochaska, Megan; Staisiunas, Daina D; Beiting, Kimberly J; Czerweic, M K; Oyler, Julie; Vinci, Lisa M; Arora, Vineet M

    2015-02-01

    Few patient-centered interventions exist to improve year-end residency clinic handoffs. Our purpose was to assess the impact of a patient-centered transition packet and comic on clinic handoff outcomes. The study was conducted at an academic medicine residency clinic. Participants were patients undergoing resident clinic handoff 2011-2013 PROGRAM DESCRIPTION: Two months before the 2012 handoff, patients received a "transition packet" incorporating patient-identified solutions (i.e., a new primary care provider (PCP) welcome letter with photo, certificate of recognition, and visit preparation tool). In 2013, a comic was incorporated to stress the importance of follow-up. Patients were interviewed by phone with response rates of 32 % in 2011, 43 % in 2012 and 36 % in 2013. Most patients who were interviewed were aware of the handoff post-packet (95 %). With the comic, more patients recalled receiving the packet (44 % 2012 vs. 64 % 2013, pcomic was associated with increased packet recall and improved follow-up rates.

  3. Year-End Clinic Handoffs: A National Survey of Academic Internal Medicine Programs.

    Science.gov (United States)

    Phillips, Erica; Harris, Christina; Lee, Wei Wei; Pincavage, Amber T; Ouchida, Karin; Miller, Rachel K; Chaudhry, Saima; Arora, Vineet M

    2017-06-01

    While there has been increasing emphasis and innovation nationwide in training residents in inpatient handoffs, very little is known about the practice and preparation for year-end clinic handoffs of residency outpatient continuity practices. Thus, the latter remains an identified, yet nationally unaddressed, patient safety concern. The 2014 annual Association of Program Directors in Internal Medicine (APDIM) survey included seven items for assessing the current year-end clinic handoff practices of internal medicine residency programs throughout the country. Nationwide survey. All internal medicine program directors registered with APDIM. Descriptive statistics of programs and tools used to formulate a year-end handoff in the ambulatory setting, methods for evaluating the process, patient safety and quality measures incorporated within the process, and barriers to conducting year-end handoffs. Of the 361 APDIM member programs, 214 (59%) completed the Transitions of Care Year-End Clinic Handoffs section of the survey. Only 34% of respondent programs reported having a year-end ambulatory handoff system, and 4% reported assessing residents for competency in this area. The top three barriers to developing a year-end handoff system were insufficient overlap between graduating and incoming residents, inability to schedule patients with new residents in advance, and time constraints for residents, attendings, and support staff. Most internal medicine programs do not have a year-end clinic handoff system in place. Greater attention to clinic handoffs and resident assessment of this care transition is needed.

  4. The third-year medical student "grapevine": managing transitions between third-year clerkships using peer-to-peer handoffs.

    Science.gov (United States)

    Masters, Dylan E; O'Brien, Bridget C; Chou, Calvin L

    2013-10-01

    As third-year medical students rotate between clerkships, they experience multiple transitions across workplace cultures and shifting learning expectations. The authors explored clerkship transitions from the students' perspective by examining the advice they passed on to their peers in preparation for new clerkships. Seventy-one students from three Veterans Affairs-based clerkship rotations at the University of California, San Francisco, School of Medicine participated in a peer-to-peer handoff session from 2008 to 2011. In the handoff session, they gave tips for optimizing performance to students starting the clerkship they had just completed. The authors transcribed student comments from four handoff sessions and used qualitative content analysis to identify and compare advice across clerkships. Students shared advice about workplace culture, content learning, logistics, and work-life balance. Common themes included expectations of the rotation, workplace norms, specific tasks, learning opportunities, and learning strategies. Comments about patient care and work-life balance were rare. Students emphasized different themes for each clerkship; for example, for some clerkships, students commented heavily on tasks and content learning, while in another students focused on workplace culture and exam preparation. These findings characterize the transitions that third-year students undergo as they rotate into new clinical training environments. Students emphasized different aspects of each clerkship in the advice they passed to their peers, and their comments often describe informal norms or opportunities that official clerkship orientations may not address. Peer-to-peer handoffs may help ease transitions between clerkships with dissimilar cultures and expectations.

  5. Assessing the implementation of a bedside service handoff on an academic hospitalist service.

    Science.gov (United States)

    Wray, Charlie M; Arora, Vineet M; Hedeker, Donald; Meltzer, David O

    2018-06-01

    Inpatient service handoffs are a vulnerable transition during a patients' hospitalization. We hypothesized that performing the service handoff at the patients' bedside may be one mechanism to more efficiently transfer patient information between physicians, while further integrating the patient into their hospital care. We performed a 6-month prospective study of performing a bedside handoff (BHO) at the service transition on a non-teaching hospitalist service. On a weekly basis, transitioning hospitalists co-rounded at patient's bedsides. Post-handoff surveys assessed for completeness of handoff, communication, missed information, and adverse events. A control group who performed the handoff via email, phone or face-to-face was also surveyed. Chi-square and item-response theory (IRT) analysis assessed for differences between BHO and control groups. Narrative responses were elicited to qualitatively describe the BHO. In total, 21/31 (67%) scheduled BHOs were performed. On average, 4 out of 6 eligible patients experienced a BHO, with a total of 90 patients experiencing a BHO. Of those asked to perform the BHO, 52% stated the service transition took 31-60 min compared to 24% in the control group. Controlling for the nesting of observations within physicians, IRT analysis found that BHO respondents had statistically significant greater odds of: reporting increased patient awareness of the service handoff, more certainty in the plan for each patient, less discovery of missed information, and less time needed to learn about the patient on the first day compared to control methods. Narrative responses described a more patient-centered handoff with improved communication that was time-consuming and often logistically difficult to implement. Despite its time-intensive nature, performing the service handoff at the patient's bedside may lead to a more complete and efficient service transition. Published by Elsevier Inc.

  6. Handoff mechanisms in LTE networks

    Science.gov (United States)

    Lal, Preeti; Yamini, Vidhu; Mohammed, V. Noor

    2017-11-01

    In this paper, we have analysed and studied the handoff mechanism in Long Term Evaluation (LTE) network. A LTE network has been defined with a set number of macro-cells, micro-cells and mobile devices. In this handoff mechanism distance and speed has been considered as an important parameters. The speed has been detected using the Gauss Markov Mobility Model, and from that distances have been predicted at different instances. In the handover process, Received Signal Power (RSP) for various users has been calculated with respect to base stations at various time intervals and the path loss between transmitter and receiver. A comparative study between path loss models is done in order to improve the signal power. A detailed study has been done on unnecessary handoff probability and handoff failure probability. Simulation results shows that there is an improvement in performance of the above mentioned parameters in the defined network.

  7. A Seamless Handoff Scheme with Access Point Load Balance for Real-Time Services Support in 802.11 Wireless LANs

    Science.gov (United States)

    Manodham, Thavisak; Loyola, Luis; Miki, Tetsuya

    IEEE 802.11 wirelesses LANs (WLANs) have been rapidly deployed in enterprises, public areas, and households. Voice-over-IP (VoIP) and similar applications are now commonly used in mobile devices over wireless networks. Recent works have improved the quality of service (QoS) offering higher data rates to support various kinds of real-time applications. However, besides the need for higher data rates, seamless handoff and load balancing among APs are key issues that must be addressed in order to continue supporting real-time services across wireless LANs and providing fair services to all users. In this paper, we introduce a novel access point (AP) with two transceivers that improves network efficiency by supporting seamless handoff and traffic load balancing in a wireless network. In our proposed scheme, the novel AP uses the second transceiver to scan and find neighboring STAs in the transmission range and then sends the results to neighboring APs, which compare and analyze whether or not the STA should perform a handoff. The initial results from our simulations show that the novel AP module is more effective than the conventional scheme and a related work in terms of providing a handoff process with low latency and sharing traffic load with neighbor APs.

  8. Transition Hand-Off from Inpatient to Outpatient Treatment of Acute Pyelonephritis in an Elderly Male.

    Science.gov (United States)

    Orlando, Patricia L; Shane-McWhorter, Laura

    2017-04-01

    Pyelonephritis is the progression of a urinary tract infection (UTI) to the kidney. In younger patients the infection may not be as severe and may even be treated with oral antibiotics. However, in elderly males pyelonephritis can be more complex and may require hospitalization and treatment with intravenous antibiotics. In the United States UTIs are responsible for frequent visits to emergency departments by elderly individuals. Current literature suggests that pyelonephritis in elderly males is a serious infection that may result in significant morbidity and mortality. Pharmacists are in a unique position to oversee the transition of antibiotic treatment from the inpatient to outpatienT SETTING.

  9. Investigating the Scope of Resident Patient Care Handoffs within Neurosurgery

    OpenAIRE

    Babu, Maya A.; Nahed, Brian Vala; Heary, Robert F.

    2012-01-01

    Introduction: Handoffs are defined as verbal and written communications during patient care transitions. With the passage of recent ACMGE work hour rules further limiting the hours interns can spend in the hospital, many fear that more handoffs will occur, putting patient safety at risk. The issue of handoffs has not been studied in the neurosurgical literature. Methods: A validated, 20-question online-survey was sent to neurosurgical residents in all 98 accredited U.S. neurosurgery programs....

  10. Improving handoffs in the emergency department.

    Science.gov (United States)

    Cheung, Dickson S; Kelly, John J; Beach, Christopher; Berkeley, Ross P; Bitterman, Robert A; Broida, Robert I; Dalsey, William C; Farley, Heather L; Fuller, Drew C; Garvey, David J; Klauer, Kevin M; McCullough, Lynne B; Patterson, Emily S; Pham, Julius C; Phelan, Michael P; Pines, Jesse M; Schenkel, Stephen M; Tomolo, Anne; Turbiak, Thomas W; Vozenilek, John A; Wears, Robert L; White, Marjorie L

    2010-02-01

    Patient handoffs at shift change are a ubiquitous and potentially hazardous process in emergency care. As crowding and lengthy evaluations become the standard for an increasing proportion of emergency departments (EDs), the number of patients handed off will likely increase. It is critical now more than ever before to ensure that handoffs supply valid and useful shared understandings between providers at transitions of care. The purpose of this article is to provide the most up-to-date evidence and collective thinking about the process and safety of handoffs between physicians in the ED. It offers perspectives from other disciplines, provides a conceptual framework for handoffs, and categorizes models of existing practices. Legal and risk management issues are also addressed. A proposal for the development of handoff quality measures is outlined. Practical strategies are suggested to improve ED handoffs. Finally, a research agenda is proposed to provide a roadmap to future work that may increase knowledge in this area. Copyright (c) 2009 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

  11. Investigating the scope of resident patient care handoffs within neurosurgery.

    Science.gov (United States)

    Babu, Maya A; Nahed, Brian V; Heary, Robert F

    2012-01-01

    Handoffs are defined as verbal and written communications during patient care transitions. With the passage of recent ACMGE work hour rules further limiting the hours interns can spend in the hospital, many fear that more handoffs will occur, putting patient safety at risk. The issue of handoffs has not been studied in the neurosurgical literature. A validated, 20-question online-survey was sent to neurosurgical residents in all 98 accredited U.S. neurosurgery programs. Survey results were analyzed using tabulations. 449 surveys were completed yielding a 56% response rate. 63% of neurosurgical residents surveyed had not received formal instruction in what constitutes an effective handoff; 24% believe there is high to moderate variability among their co-residents in terms of the quality of the handoff provided; 55% experience three or more interruptions during handoffs on average. 90% of neurosurgical residents surveyed say that handoff most often occurs in a quiet, private area and 56% report a high level of comfort for knowing the potential acute, critical issues affecting a patient when receiving a handoff. There needs to be more focused education devoted to learning effective patient-care handoffs in neurosurgical training programs. Increasingly, handing off a patient adequately and safely is becoming a required skill of residency.

  12. Investigating the scope of resident patient care handoffs within neurosurgery.

    Directory of Open Access Journals (Sweden)

    Maya A Babu

    Full Text Available INTRODUCTION: Handoffs are defined as verbal and written communications during patient care transitions. With the passage of recent ACMGE work hour rules further limiting the hours interns can spend in the hospital, many fear that more handoffs will occur, putting patient safety at risk. The issue of handoffs has not been studied in the neurosurgical literature. METHODS: A validated, 20-question online-survey was sent to neurosurgical residents in all 98 accredited U.S. neurosurgery programs. Survey results were analyzed using tabulations. RESULTS: 449 surveys were completed yielding a 56% response rate. 63% of neurosurgical residents surveyed had not received formal instruction in what constitutes an effective handoff; 24% believe there is high to moderate variability among their co-residents in terms of the quality of the handoff provided; 55% experience three or more interruptions during handoffs on average. 90% of neurosurgical residents surveyed say that handoff most often occurs in a quiet, private area and 56% report a high level of comfort for knowing the potential acute, critical issues affecting a patient when receiving a handoff. CONCLUSIONS: There needs to be more focused education devoted to learning effective patient-care handoffs in neurosurgical training programs. Increasingly, handing off a patient adequately and safely is becoming a required skill of residency.

  13. A Delphi study to identify the core components of nurse to nurse handoff.

    Science.gov (United States)

    O'Rourke, Jennifer; Abraham, Joanna; Riesenberg, Lee Ann; Matson, Jeff; Lopez, Karen Dunn

    2018-03-08

    The aim of this study was to identify the core components of nurse-nurse handoffs. Patient handoffs involve a process of passing information, responsibility and control from one caregiver to the next during care transitions. Around the globe, ineffective handoffs have serious consequences resulting in wrong treatments, delays in diagnosis, longer stays, medication errors, patient falls and patient deaths. To date, the core components of nurse-nurse handoff have not been identified. This lack of identification is a significant gap in moving towards a standardized approach for nurse-nurse handoff. Mixed methods design using the Delphi technique. From May 2016 - October 2016, using a series of iterative steps, a panel of handoff experts gave feedback on the nurse-nurse handoff core components and the content in each component to be passed from one nurse to the next during a typical unit-based shift handoff. Consensus was defined as 80% agreement or higher. After three rounds of participant review, 17 handoff experts with backgrounds in clinical nursing practice, academia and handoff research came to consensus on the core components of handoff: patient summary, action plan and nurse-nurse synthesis. This is the first study to identify the core components of nurse-nurse handoff. Subsequent testing of the core components will involve evaluating the handoff approach in a simulated and then actual patient care environment. Our long-term goal is to improve patient safety outcomes by validating an evidence-based handoff framework and handoff curriculum for pre-licensure nursing programmes that strengthen the quality of their handoff communication as they enter clinical practice. © 2018 John Wiley & Sons Ltd.

  14. Implementation of postoperative handoff protocol

    African Journals Online (AJOL)

    Background: Standardised handoff protocols have become necessary patient ... improve the perioperative handoff communications from the cardiac operating theatres to the ICU. ..... as you can imagine, there was push-back to the change.

  15. Handoffs causing patient harm: a survey of medical and surgical house staff.

    Science.gov (United States)

    Kitch, Barrett T; Cooper, Jeffrey B; Zapol, Warren M; Marder, Jessica E; Karson, Andrew; Hutter, Matt; Campbell, Eric G

    2008-10-01

    Communication lapses at the time of patient handoffs are believed to be common, and yet the frequency with which patients are harmed as a result of problematic handoffs is unknown. Resident physicians were surveyed about their handoffpractices and the frequency with which they perceive problems with handoffs lead to patient harm. A survey was conducted in 2006 of all resident physicians in internal medicine and general surgery at Massachusetts General Hospital (MGH) concerning the quality and effects of handoffs during their most recent inpatient rotations. Surveys were sent to 238 eligible residents; 161 responses were obtained (response rate, 67.6%). Fifty-nine percent of residents reported that one or more patients had been harmed during their most recent clinical rotation because of problematic handoffs, and 12% reported that this harm had been major. Overall quality of handoffs was reported to be fair or poor by 31% of residents. A minority of residents (26%) reported that handoffs usually or always took place in a quiet setting, and 37% reported that one or more interruptions during the receipt of handoffs occurred either most of the time or always. Although handoffs have long been recognized as potentially hazardous, further scrutiny of handoffs has followed recent reports that handoffs are often marked by missing, incomplete, or inaccurate information and are associated with adverse events. In this study, reports of harm to patients from problematic handoffs were common among residents in internal medicine and general surgery. Many best-practice recommendations for handoffs are not observed, although the extent to which improvement of these practices could reduce patient harm is not known. MGH has recently launched a handoff-safety educational program, along with other interventions designed to improve the safety and effectiveness of handoffs, for its house staff and clinical leadership.

  16. Using peers to assess handoffs: a pilot study.

    Science.gov (United States)

    Dine, C Jessica; Wingate, Nicholas; Rosen, Ilene M; Myers, Jennifer S; Lapin, Jennifer; Kogan, Jennifer R; Shea, Judy A

    2013-08-01

    Handoffs among post-graduate year 1 (PGY1) trainees occur with high frequency. Peer assessment of handoff competence would add a new perspective on how well the handoff information helped them to provide optimal patient care. The goals of this study were to test the feasibility of the approach of an instrument for peer assessment of handoffs by meeting criteria of being able to use technology to capture evaluations in real time, exhibiting strong psychometric properties, and having high PGY1 satisfaction scores. An iPad® application was built for a seven-item handoff instrument. Over a two-month period, post-call PGY1s completed assessments of three co-PGY1s from whom they received handoffs the prior evening. Internal Medicine PGY1s at the University of Pennsylvania. ANOVA was used to explore interperson score differences (validity). Generalizability analyses provided estimates of score precision (reproducibility). PGY1s completed satisfaction surveys about the process. Sixty-two PGY1s (100 %) participated in the study. 59 % of the targeted evaluations were completed. The major limitations were network connectivity and inability to find the post-call trainee. PGY1 scores on the single item of "overall competency" ranged from 4 to 9 with a mean of 7.31 (SD 1.09). Generalizability coefficients approached 0.60 for 10 evaluations per PGY1 for a single rotation and 12 evaluations per PGY1 across multiple rotations. The majority of PGY1s believed that they could adequately assess handoff competence and that the peer assessment process was valuable (70 and 77 %, respectively). Psychometric properties of an instrument for peer assessment of handoffs are encouraging. Obtaining 10 or 12 evaluations per PGY1 allowed for reliable assessment of handoff skills. Peer evaluations of handoffs using mobile technology were feasible, and were well received by PGY1s.

  17. Seamless handoff in Mobile IP

    NARCIS (Netherlands)

    Karagiannis, Georgios; Heijenk, Geert; El Malki, Karim; Soliman, Hesham

    2001-01-01

    In a system and method for handing off a mobile node in a seamless manner in a wireless access network, procedures are implemented for allowing the mobile node to synchronize the handoff with a base node (e.g., a home agent) and a correspondent node. In this way, a seamless handoff may be achieved,

  18. A Novel Process Audit for Standardized Perioperative Handoff Protocols.

    Science.gov (United States)

    Pallekonda, Vinay; Scholl, Adam T; McKelvey, George M; Amhaz, Hassan; Essa, Deanna; Narreddy, Spurthy; Tan, Jens; Templonuevo, Mark; Ramirez, Sasha; Petrovic, Michelle A

    2017-11-01

    A perioperative handoff protocol provides a standardized delivery of communication during a handoff that occurs from the operating room to the postanestheisa care unit or ICU. The protocol's success is dependent, in part, on its continued proper use over time. A novel process audit was developed to help ensure that a perioperative handoff protocol is used accurately and appropriately over time. The Audit Observation Form is used for the Audit Phase of the process audit, while the Audit Averages Form is used for the Data Analysis Phase. Employing minimal resources and using quantitative methods, the process audit provides the necessary means to evaluate the proper execution of any perioperative handoff protocol. Copyright © 2017 The Joint Commission. Published by Elsevier Inc. All rights reserved.

  19. Characterising physician listening behaviour during hospitalist handoffs using the HEAR checklist.

    Science.gov (United States)

    Greenstein, Elizabeth A; Arora, Vineet M; Staisiunas, Paul G; Banerjee, Stacy S; Farnan, Jeanne M

    2013-03-01

    The increasing fragmentation of healthcare has resulted in more patient handoffs. Many professional groups, including the Accreditation Council on Graduate Medical Education and the Society of Hospital Medicine, have made recommendations for safe and effective handoffs. Despite the two-way nature of handoff communication, the focus of these efforts has largely been on the person giving information. To observe and characterise the listening behaviours of handoff receivers during hospitalist handoffs. Prospective observational study of shift change and service change handoffs on a non-teaching hospitalist service at a single academic tertiary care institution. The 'HEAR Checklist', a novel tool created based on review of effective listening behaviours, was used by third party observers to characterise active and passive listening behaviours and interruptions during handoffs. In 48 handoffs (25 shift change, 23 service change), active listening behaviours (eg, read-back (17%), note-taking (23%) and reading own copy of the written signout (27%)) occurred less frequently than passive listening behaviours (eg, affirmatory statements (56%) nodding (50%) and eye contact (58%)) (pRead-back occurred only eight times (17%). In 11 handoffs (23%) receivers took notes. Almost all (98%) handoffs were interrupted at least once, most often by side conversations, pagers going off, or clinicians arriving. Handoffs with more patients, such as service change, were associated with more interruptions (r=0.46, plistening behaviours. While passive listening behaviours are common, active listening behaviours that promote memory retention are rare. Handoffs are often interrupted, most commonly by side conversations. Future handoff improvement efforts should focus on augmenting listening and minimising interruptions.

  20. Pemodelan dan Verifikasi Formal Pengaruh Mobility pattern Terhadap Handoff Latency pada Jaringan WiMAX

    Directory of Open Access Journals (Sweden)

    I Nym Saputra Wahyu Wijaya

    2016-01-01

    Full Text Available In order to decrease handoff latency and increase the successful of HHO conventional scheme, a development of handover scheme is done in standard protocol WiMAX IEEE 802.16e by adding mobility pattern. The superiority of handover scheme with mobility pattern can reduce handoff latency up to 50%, mean while the weakness of this scheme is a wrong act in determining target base station are often happen. Simulation can not showing the cause of that error. So, we do formal verification in to hard handover model with mobility pattern.             In this research, behaviour system is modeled with continuous-time Markov chain (CTMC. The model is foccused to aproximating the influence of mobility pattern in to handoff latency from WiMAX hard handover mechanism. In order to set up a series markov chain models handover system can follow steps, such as: represents the state space, give a number in all transitions, generate the rate transition matrix (infinitesimal generator.             Probabilistic model checking in the research are using quantitative properties and qualitative properties. Formal verification concerning properties has relation with handover in WiMAX network showing that 70% from mobile station which doing scanning with mobility pattern are success doing handover. 24% of them doing scanning conventional as a result of wrongness in act determining target base station, so handoff latency which is pictured will bigger than a system that is only use conventional scanning method.

  1. Implementation of Dynamic Smart Decision Model for Vertical Handoff

    Science.gov (United States)

    Sahni, Nidhi

    2010-11-01

    International Mobile Telecommunications-Advanced (IMT Advanced), better known as 4G is the next level of evolution in the field of wireless communications. 4G Wireless networks enable users to access information anywhere, anytime, with a seamless connection to a wide range of information and services, and receiving a large volume of information, data, pictures, video and thus increasing the demand for High Bandwidth and Signal Strength. The mobility among various networks is achieved through Vertical Handoff. Vertical handoffs refer to the automatic failover from one technology to another in order to maintain communication. The heterogeneous co-existence of access technologies with largely different characteristics creates a decision problem of determining the "best" available network at "best" time for handoff. In this paper, we implemented the proposed Dynamic and Smart Decision model to decide the "best" network interface and "best" time moment to handoff. The proposed model implementation not only demonstrates the individual user needs but also improve the whole system performance i.e. Quality of Service by reducing the unnecessary handoffs and maintain mobility.

  2. Changes in medical errors after implementation of a handoff program.

    Science.gov (United States)

    Starmer, Amy J; Spector, Nancy D; Srivastava, Rajendu; West, Daniel C; Rosenbluth, Glenn; Allen, April D; Noble, Elizabeth L; Tse, Lisa L; Dalal, Anuj K; Keohane, Carol A; Lipsitz, Stuart R; Rothschild, Jeffrey M; Wien, Matthew F; Yoon, Catherine S; Zigmont, Katherine R; Wilson, Karen M; O'Toole, Jennifer K; Solan, Lauren G; Aylor, Megan; Bismilla, Zia; Coffey, Maitreya; Mahant, Sanjay; Blankenburg, Rebecca L; Destino, Lauren A; Everhart, Jennifer L; Patel, Shilpa J; Bale, James F; Spackman, Jaime B; Stevenson, Adam T; Calaman, Sharon; Cole, F Sessions; Balmer, Dorene F; Hepps, Jennifer H; Lopreiato, Joseph O; Yu, Clifton E; Sectish, Theodore C; Landrigan, Christopher P

    2014-11-06

    Miscommunications are a leading cause of serious medical errors. Data from multicenter studies assessing programs designed to improve handoff of information about patient care are lacking. We conducted a prospective intervention study of a resident handoff-improvement program in nine hospitals, measuring rates of medical errors, preventable adverse events, and miscommunications, as well as resident workflow. The intervention included a mnemonic to standardize oral and written handoffs, handoff and communication training, a faculty development and observation program, and a sustainability campaign. Error rates were measured through active surveillance. Handoffs were assessed by means of evaluation of printed handoff documents and audio recordings. Workflow was assessed through time-motion observations. The primary outcome had two components: medical errors and preventable adverse events. In 10,740 patient admissions, the medical-error rate decreased by 23% from the preintervention period to the postintervention period (24.5 vs. 18.8 per 100 admissions, P<0.001), and the rate of preventable adverse events decreased by 30% (4.7 vs. 3.3 events per 100 admissions, P<0.001). The rate of nonpreventable adverse events did not change significantly (3.0 and 2.8 events per 100 admissions, P=0.79). Site-level analyses showed significant error reductions at six of nine sites. Across sites, significant increases were observed in the inclusion of all prespecified key elements in written documents and oral communication during handoff (nine written and five oral elements; P<0.001 for all 14 comparisons). There were no significant changes from the preintervention period to the postintervention period in the duration of oral handoffs (2.4 and 2.5 minutes per patient, respectively; P=0.55) or in resident workflow, including patient-family contact and computer time. Implementation of the handoff program was associated with reductions in medical errors and in preventable adverse events

  3. Nurse-to-nurse shift handoffs on medical-surgical units: A process within the flow of nursing care.

    Science.gov (United States)

    Ernst, Katherine M; McComb, Sara A; Ley, Cathaleen

    2018-03-01

    To qualitatively investigate the medical-surgical nurse shift handoff as a process within the workflow of the exchanging nurses. Specifically, this study sought to identify the ideal handoff, ways the handoff deviated from ideal, and subsequent effect on nursing care. The functions as well as information content of the handoff have been studied. However, typical studies look at the handoff as an isolated activity utilising nurse perceptions as the primary measure of quality. Semi-structured focus groups were conducted to discuss nurses' perspectives on ideal handoffs, ways handoffs deviate from the ideal including frequent and significant deviations and the effects on subsequent care. Twenty-one medical-surgical nurses participated in one of five audio-taped focus group sessions. Three sessions were conducted at hospital A; two sessions at unaffiliated hospital B. The general inductive approach was used to analyse verbatim transcripts. Transcript segments relevant for answering the research questions were coded as ideal or not ideal. Conceptual themes were then developed. Two major themes were identified: teams/teamwork and constructing and communicating a shared understanding of the patients' conditions. The importance of nurse preparatory activities was revealed including the incoming nurses reading patients' health records and outgoing nurses rounding on patients. The impact of shared expectations was identified across the team, where teams include, in addition to the two nurses, the electronic health record, other hospital staff and patients/families with a bedside handoff. New potential nurse-centred process and outcome measures were proposed. Evaluating handoffs by their effect on the nursing performance both during and after the handoff offers a new framework to objectively assess handoff effectiveness. The handoff is a process which may significantly affect the incoming nurse's transition into and administration of nursing care. © 2018 John Wiley & Sons

  4. Face-to-face handoff: improving transfer to the pediatric intensive care unit after cardiac surgery.

    Science.gov (United States)

    Vergales, Jeffrey; Addison, Nancy; Vendittelli, Analise; Nicholson, Evelyn; Carver, D Jeannean; Stemland, Christopher; Hoke, Tracey; Gangemi, James

    2015-01-01

    The goal was to develop and implement a comprehensive, primarily face-to-face handoff process that begins in the operating room and concludes at the bedside in the intensive care unit (ICU) for pediatric patients undergoing congenital heart surgery. Involving all stakeholders in the planning phase, the framework of the handoff system encompassed a combination of a formalized handoff tool, focused process steps that occurred prior to patient arrival in the ICU, and an emphasis on face-to-face communication at the conclusion of the handoff. The final process was evaluated by the use of observer checklists to examine quality metrics and timing for all patients admitted to the ICU following cardiac surgery. The process was found to improve how various providers view the efficiency of handoff, the ease of asking questions at each step, and the overall capability to improve patient care regardless of overall surgical complexity. © 2014 by the American College of Medical Quality.

  5. Effects of the I-PASS Nursing Handoff Bundle on communication quality and workflow.

    Science.gov (United States)

    Starmer, Amy J; Schnock, Kumiko O; Lyons, Aimee; Hehn, Rebecca S; Graham, Dionne A; Keohane, Carol; Landrigan, Christopher P

    2017-12-01

    Handoff communication errors are a leading source of sentinel events. We sought to determine the impact of a handoff improvement programme for nurses. We conducted a prospective pre-post intervention study on a paediatric intensive care unit in 2011-2012. The I-PASS Nursing Handoff Bundle intervention consisted of educational training, verbal handoff I-PASS mnemonic implementation, and visual materials to provide reinforcement and sustainability. We developed handoff direct observation and time motion workflow assessment tools to measure: (1) quality of the verbal handoff, including interruption frequency and presence of key handoff data elements; and (2) duration of handoff and other workflow activities. I-PASS implementation was associated with improvements in verbal handoff communications, including inclusion of illness severity assessment (37% preintervention vs 67% postintervention, p=0.001), patient summary (81% vs 95%, p=0.05), to do list (35% vs 100%, p<0.001) and an opportunity for the receiving nurse to ask questions (34% vs 73%, p<0.001). Overall, 13/21 (62%) of verbal handoff data elements were more likely to be present following implementation whereas no data elements were less likely present. Implementation was associated with a decrease in interruption frequency pre versus post intervention (67% vs 40% of handoffs with interruptions, p=0.005) without a change in the median handoff duration (18.8 min vs 19.9 min, p=0.48) or changes in time spent in direct or indirect patient care activities. Implementation of the I-PASS Nursing Handoff Bundle was associated with widespread improvements in the verbal handoff process without a negative impact on nursing workflow. Implementation of I-PASS for nurses may therefore have the potential to significantly reduce medical errors and improve patient safety. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted

  6. Rates of medical errors and preventable adverse events among hospitalized children following implementation of a resident handoff bundle.

    Science.gov (United States)

    Starmer, Amy J; Sectish, Theodore C; Simon, Dennis W; Keohane, Carol; McSweeney, Maireade E; Chung, Erica Y; Yoon, Catherine S; Lipsitz, Stuart R; Wassner, Ari J; Harper, Marvin B; Landrigan, Christopher P

    2013-12-04

    Handoff miscommunications are a leading cause of medical errors. Studies comprehensively assessing handoff improvement programs are lacking. To determine whether introduction of a multifaceted handoff program was associated with reduced rates of medical errors and preventable adverse events, fewer omissions of key data in written handoffs, improved verbal handoffs, and changes in resident-physician workflow. Prospective intervention study of 1255 patient admissions (642 before and 613 after the intervention) involving 84 resident physicians (42 before and 42 after the intervention) from July-September 2009 and November 2009-January 2010 on 2 inpatient units at Boston Children's Hospital. Resident handoff bundle, consisting of standardized communication and handoff training, a verbal mnemonic, and a new team handoff structure. On one unit, a computerized handoff tool linked to the electronic medical record was introduced. The primary outcomes were the rates of medical errors and preventable adverse events measured by daily systematic surveillance. The secondary outcomes were omissions in the printed handoff document and resident time-motion activity. Medical errors decreased from 33.8 per 100 admissions (95% CI, 27.3-40.3) to 18.3 per 100 admissions (95% CI, 14.7-21.9; P < .001), and preventable adverse events decreased from 3.3 per 100 admissions (95% CI, 1.7-4.8) to 1.5 (95% CI, 0.51-2.4) per 100 admissions (P = .04) following the intervention. There were fewer omissions of key handoff elements on printed handoff documents, especially on the unit that received the computerized handoff tool (significant reductions of omissions in 11 of 14 categories with computerized tool; significant reductions in 2 of 14 categories without computerized tool). Physicians spent a greater percentage of time in a 24-hour period at the patient bedside after the intervention (8.3%; 95% CI 7.1%-9.8%) vs 10.6% (95% CI, 9.2%-12.2%; P = .03). The average duration of verbal

  7. A Multimetric Approach for Handoff Decision in Heterogeneous Wireless Networks

    Science.gov (United States)

    Kustiawan, I.; Purnama, W.

    2018-02-01

    Seamless mobility and service continuity anywhere at any time are an important issue in the wireless Internet. This research proposes a scheme to make handoff decisions effectively in heterogeneous wireless networks using a fuzzy system. Our design lies in an inference engine which takes RSS (received signal strength), data rate, network latency, and user preference as strategic determinants. The logic of our engine is realized on a UE (user equipment) side in faster reaction to network dynamics while roaming across different radio access technologies. The fuzzy system handles four metrics jointly to deduce a moderate decision about when to initiate handoff. The performance of our design is evaluated by simulating move-out mobility scenarios. Simulation results show that our scheme outperforms other approaches in terms of reducing unnecessary handoff.

  8. A Location-Aware Vertical Handoff Algorithm for Hybrid Networks

    KAUST Repository

    Mehbodniya, Abolfazl; Aissa, Sonia; Chitizadeh, Jalil

    2010-01-01

    . Horizontal handoff, or generally speaking handoff, is a process which maintains a mobile user's active connection as it moves within a wireless network, whereas vertical handoff (VHO) refers to handover between different types of networks or different network

  9. Development of a Nursing Handoff Tool: A Web-Based Application to Enhance Patient Safety

    Science.gov (United States)

    Goldsmith, Denise; Boomhower, Marc; Lancaster, Diane R.; Antonelli, Mary; Kenyon, Mary Anne Murphy; Benoit, Angela; Chang, Frank; Dykes, Patricia C.

    2010-01-01

    Dynamic and complex clinical environments present many challenges for effective communication among health care providers. The omission of accurate, timely, easily accessible vital information by health care providers significantly increases risk of patient harm and can have devastating consequences for patient care. An effective nursing handoff supports the standardized transfer of accurate, timely, critical patient information, as well as continuity of care and treatment, resulting in enhanced patient safety. The Brigham and Women’s/Faulkner Hospital Healthcare Information Technology Innovation Program (HIP) is supporting the development of a web based nursing handoff tool (NHT). The goal of this project is to develop a “proof of concept” handoff application to be evaluated by nurses on the inpatient intermediate care units. The handoff tool would enable nurses to use existing knowledge of evidence-based handoff methodology in their everyday practice to improve patient care and safety. In this paper, we discuss the results of nursing focus groups designed to identify the current state of handoff practice as well as the functional and data element requirements of a web based Nursing Handoff Tool (NHT). PMID:21346980

  10. Effect of handoff skills training for students during the medicine clerkship: a quasi-randomized study.

    Science.gov (United States)

    Reyes, Juan A; Greenberg, Larrie; Amdur, Richard; Gehring, James; Lesky, Linda G

    2016-03-01

    Continuity is critical for safe patient care and its absence is associated with adverse outcomes. Continuity requires handoffs between physicians, but most published studies of educational interventions to improve handoffs have focused primarily on residents, despite interns expected to being proficient. The AAMC core entrustable activities for graduating medical students includes handoffs as a milestone, but no controlled studies with students have assessed the impact of training in handoff skills. The purpose of this study was to assess the impact of an educational intervention to improve third-year medical student handoff skills, the durability of learned skills into the fourth year, and the transfer of skills from the simulated setting to the clinical environment. Trained evaluators used standardized patient cases and an observation tool to assess verbal handoff skills immediately post intervention and during the student's fourth-year acting internship. Students were also observed doing real time sign-outs during their acting internship. Evaluators assessed untrained control students using a standardized case and performing a real-time sign-out. Intervention students mean score demonstrated improvement in handoff skills immediately after the workshop (2.6-3.8; p < 0.0001) that persisted into their fourth year acting internship when compared to baseline performance (3.9-3.5; p = 0.06) and to untrained control students (3.5 vs. 2.5; p < 0.001, d = 1.2). Intervention students evaluated in the clinical setting also scored higher than control students when assessed doing real-time handoffs (3.8 vs. 3.3; p = 0.032, d = 0.71). These findings should be useful to others considering introducing handoff teaching in the undergraduate medical curriculum in preparation for post-graduate medical training. Trial Registration Number NCT02217241.

  11. Patient Handoff Education: Are Medical Schools Catching Up?

    Science.gov (United States)

    Davis, Robyn; Davis, Joshua; Berg, Katherine; Berg, Dale; Morgan, Charity J; Russo, Stefani; Riesenberg, Lee Ann

    Communication errors during shift-to-shift handoffs are a leading cause of preventable adverse events. Nevertheless, handoff skills are variably taught at medical schools. The authors administered questionnaires on handoffs to interns during orientation. Questions focused on medical school handoff education, experiences, and perceptions. The majority (546/718) reported having some form of education on handoffs during medical school, with 48% indicating this was 1 hour or less. Most respondents (98%) reported that they believe patients experience adverse events because of inadequate handoffs, and more than one third had witnessed a patient safety issue. Results show that medical school graduates are not receiving adequate handoff training. Yet graduates are expected to conduct safe patient handoffs at the start of residency. Given that ineffective handoffs pose a significant patient safety risk, medical school graduates should have a baseline competency in handoff skills. This will require medical schools to develop, implement, and study handoff education.

  12. Group handoff management in low power microcell-femtocell network

    Directory of Open Access Journals (Sweden)

    Debashis De

    2017-02-01

    Full Text Available This paper presents an analytical model of group based hand-off management based on bird flocking behavior. In the proposed scheme, a number of mobile devices form a group if these devices move together for a long time duration. Although call delivery or call generation are performed individually, hand-off is performed in a group. Dynamic group formation, group division and group merging methods are proposed in this paper. From the simulation results it is demonstrated that approximately 75%, 65% and 90% reduction in power, cost and latency consumption can be obtained respectively using group hand-off management. Thus the proposed scheme is referred as green, economic and fast hand-off strategy. In this paper instead of a macrocell network, a microcell-femtocell network is considered as the transmission power of a microcell or a femtocell base station is much less than a macrocell base station. Simulation results present that the microcell-femtocell network achieves approximately 25–55% and 35–55% reduction in power transmission, and 50–65% and 15–45% reduction in path loss than only a macrocell network and macrocell-femtocell network respectively. Thus microcell-femtocell network is a power-efficient network.

  13. Structured patient handoff on an internal medicine ward: A cluster randomized control trial.

    Science.gov (United States)

    Tam, Penny; Nijjar, Aman P; Fok, Mark; Little, Chris; Shingina, Alexandra; Bittman, Jesse; Raghavan, Rashmi; Khan, Nadia A

    2018-01-01

    The effect of a multi-faceted handoff strategy in a high volume internal medicine inpatient setting on process and patient outcomes has not been clearly established. We set out to determine if a multi-faceted handoff intervention consisting of education, standardized handoff procedures, including fixed time and location for face-to-face handoff would result in improved rates of handoff compared with usual practice. We also evaluated resident satisfaction, health resource utilization and clinical outcomes. This was a cluster randomized controlled trial in a large academic tertiary care center with 18 inpatient internal medicine ward teams from January-April 2013. We randomized nine inpatient teams to an intervention where they received an education session standardizing who and how to handoff patients, with practice and feedback from facilitators. The control group of 9 teams continued usual non-standardized handoffs. The primary process outcome was the rate of patients handed over per 1000 patient nights. Other process outcomes included perceptions of inadequate handoff by overnight physicians, resource utilization overnight and hospital length of stay. Clinical outcomes included medical errors, frequency of patients requiring higher level of care overnight, and in-hospital mortality. The intervention group demonstrated a significant increase in the rate of patients handed over to the overnight physician (62.90/1000 person-nights vs. 46.86/1000 person-nights, p = 0.002). There was no significant difference in other process outcomes except resource utilization was increased in the intervention group (26.35/1000 person-days vs. 17.57/1000 person-days, p-value = 0.01). There was no significant difference between groups in medical errors (4.8% vs. 4.1%), need for higher level of care or in hospital mortality. Limitations include a dependence of accurate record keeping by the overnight physician, the possibility of cross-contamination in the handoff process, analysis at

  14. Transit time for resonant tunneling

    International Nuclear Information System (INIS)

    Garcia Calderon, G.; Rubio, A.

    1990-09-01

    This work considers properties of the partial widths in one dimensional elastic resonant tunneling in order to propose a transit-time τ tr = (h/2π)/Γ n T res ) where Γ n is the elastic width and T res the transmission coefficient at resonance energy. This time is interpreted as an average over the resonance energy width. It is shown that the tunneling current density integrated across a sharp resonance is inversely proportional to τ tr . This transit time may be much larger than the values predicted by other definitions. (author). 20 refs

  15. Patient Handoffs in Obstetrics and Gynecology: A Vital Link in Patient Safety

    Directory of Open Access Journals (Sweden)

    John Yeh

    2009-01-01

    Full Text Available Inadequate patient handoffs have been an area of focus for patient safety improvement. Insufficient communication and risks or “shortcuts” taken by staff members during handoffs could negatively affect the safety of patients in a department of obstetrics and gynecology. Other factors that contribute to inadequate handoffs are the caregiver feeling fatigued or stressed, level of urgency, volume of information, language barriers, noise, lighting, ambiguity of describing treatment, not allotting enough time for questions asked, and/or interruptions from other staff members. There have been several methods developed for improving the handoff process, such as the mnemonic devices SBAR, SHARQ, I PASS THE BATON, and the 5 P's. A new method for improving the quality of patient handoffs has been developed and presented in this article. It is a mnemonic device entitled “HANDOFFS”. It covers key aspects of what a handoff process should entail. Teamwork is essential to effective communication, and by using a mnemonic such as this, team members can work together in a more positive and accessible environment that will result in improved patient safety.

  16. "Mr Smith's been our problem child today…": anticipatory management communication (AMC) in VA end-of-shift medicine and nursing handoffs.

    Science.gov (United States)

    Bergman, Alicia A; Flanagan, Mindy E; Ebright, Patricia R; O'Brien, Colleen M; Frankel, Richard M

    2016-02-01

    Tools and procedures designed to improve end-of-shift handoffs through standardisation of processes and reliance on technology may miss contextually sensitive information about anticipated events that emerges during face-to-face handoff interactions. Such information, what we refer to as anticipatory management communication (AMC), is necessary to ensure timely and safe patient care, but has been little studied and understood. To investigate AMC and the role it plays in nursing and medicine handoffs. Qualitative thematic analysis based on audio recordings of nurse-to-nurse, medical resident-to-resident and surgical intern-to-intern handoffs. 27 nurse handoff dyads and 18 medical resident and surgical intern handoff dyads at one VA Medical Center. Heads-up information was the most frequent type of AMC across all handoff dyads (N=257; 108 resident and 149 nursing). Indirect instructions AMC was used in a little over half the resident handoff dyads, but occurred in all nursing dyads (292 instances). Direct instructions AMC occurred in roughly equal proportion across all dyads but at a modest frequency (N=45; 28 resident and 17 nursing). Direct (if/then) contingency AMC occurred in resident handoffs more frequently than in nursing handoffs (N=32; 30 resident and 2 nursing). The different frequencies for types of AMC likely reflect differences in how residents and nurses work and disparate professional cultures. But, verbal communication in both groups included important information unlikely to be captured in written handoff tools or the electronic medical record, underscoring the importance of direct communication to ensure safe handoffs. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  17. A Literature Survey on Handoff for Mobile IPv6

    OpenAIRE

    Zongpu Jia; Gaolei Wang; Ran Zhao

    2011-01-01

    With the development of network technology, IPv6 will be widely used in the next generation Internet, IPv6 will be used in the next generation Internet, IPv6 could combine mobile networks and fixed wireless networks closely, which brings great convenience to people’s live. The handoff delay of Mobile IPv6 seriously affected the real-time communication service quality, therefore various improvement methods based on the basic Mobile IPv6 protocol are proposed. The working principle of Mob...

  18. Unpacking the Complexity of Patient Handoffs Through the Lens of Cognitive Load Theory.

    Science.gov (United States)

    Young, John Q; Ten Cate, Olle; O'Sullivan, Patricia S; Irby, David M

    2016-01-01

    The transfer of a patient from one clinician to another is a high-risk event. Errors are common and lead to patient harm. More effective methods for learning how to give and receive sign-out is an important public health priority. Performing a handoff is a complex task. Trainees must simultaneously apply and integrate clinical, communication, and systems skills into one time-limited and highly constrained activity. The task demands can easily exceed the information-processing capacity of the trainee, resulting in impaired learning and performance. Appreciating the limits of working memory can help identify the challenges that instructional techniques and research must then address. Cognitive load theory (CLT) identifies three types of load that impact working memory: intrinsic (task-essential), extraneous (not essential to task), and germane (learning related). The authors generated a list of factors that affect a trainee's learning and performance of a handoff based on CLT. The list was revised based on feedback from experts in medical education and in handoffs. By consensus, the authors associated each factor with the type of cognitive load it primarily effects. The authors used this analysis to build a conceptual model of handoffs through the lens of CLT. The resulting conceptual model unpacks the complexity of handoffs and identifies testable hypotheses for educational research and instructional design. The model identifies features of a handoff that drive extraneous, intrinsic, and germane load for both the sender and the receiver. The model highlights the importance of reducing extraneous load, matching intrinsic load to the developmental stage of the learner and optimizing germane load. Specific CLT-informed instructional techniques for handoffs are explored. Intrinsic and germane load are especially important to address and include factors such as knowledge of the learner, number of patients, time constraints, clinical uncertainties, overall patient

  19. A Reliable Handoff Mechanism for Mobile Industrial Wireless Sensor Networks.

    Science.gov (United States)

    Ma, Jian; Yang, Dong; Zhang, Hongke; Gidlund, Mikael

    2017-08-04

    With the prevalence of low-power wireless devices in industrial applications, concerns about timeliness and reliability are bound to continue despite the best efforts of researchers to design Industrial Wireless Sensor Networks (IWSNs) to improve the performance of monitoring and control systems. As mobile devices have a major role to play in industrial production, IWSNs should support mobility. However, research on mobile IWSNs and practical tests have been limited due to the complicated resource scheduling and rescheduling compared with traditional wireless sensor networks. This paper proposes an effective mechanism to guarantee the performance of handoff, including a mobility-aware scheme, temporary connection and quick registration. The main contribution of this paper is that the proposed mechanism is implemented not only in our testbed but in a real industrial environment. The results indicate that our mechanism not only improves the accuracy of handoff triggering, but also solves the problem of ping-pong effect during handoff. Compared with the WirelessHART standard and the RSSI-based approach, our mechanism facilitates real-time communication while being more reliable, which can help end-to-end packet delivery remain an average of 98.5% in the scenario of mobile IWSNs.

  20. Coordinating Transit Transfers in Real Time

    Science.gov (United States)

    2016-05-06

    Transfers are a major source of travel time variability for transit passengers. Coordinating transfers between transit routes in real time can reduce passenger waiting times and travel time variability, but these benefits need to be contrasted with t...

  1. Establishing a conceptual framework for handoffs using communication theory.

    Science.gov (United States)

    Mohorek, Matthew; Webb, Travis P

    2015-01-01

    A significant consequence of the 2003 Accreditation Council for Graduate Medical Education duty hour restrictions has been the dramatic increase in patient care handoffs. Ineffective handoffs have been identified as the third most common cause of medical error. However, research into health care handoffs lacks a unifying foundational structure. We sought to identify a conceptual framework that could be used to critically analyze handoffs. A scholarly review focusing on communication theory as a possible conceptual framework for handoffs was conducted. A PubMed search of published handoff research was also performed, and the literature was analyzed and matched to the most relevant theory for health care handoff models. The Shannon-Weaver Linear Model of Communication was identified as the most appropriate conceptual framework for health care handoffs. The Linear Model describes communication as a linear process. A source encodes a message into a signal, the signal is sent through a channel, and the signal is decoded back into a message at the destination, all in the presence of internal and external noise. The Linear Model identifies 3 separate instances in handoff communication where error occurs: the transmitter (message encoding), channel, and receiver (signal decoding). The Linear Model of Communication is a suitable conceptual framework for handoff research and provides a structured approach for describing handoff variables. We propose the Linear Model should be used as a foundation for further research into interventions to improve health care handoffs. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  2. Spectrum Handoffs Based on Preemptive Repeat Priority Queue in Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    Xiaolong Yang

    2016-07-01

    Full Text Available Cognitive radio can significantly improve the spectrum efficiency, and spectrum handoff is considered as an important functionality to guarantee the quality of service (QoS of primary users (PUs and the continuity of data transmission of secondary users (SUs. In this paper, we propose an analytical framework based on a preemptive repeat identical (PRI M/G/1 queuing network model to characterize spectrum handoff behaviors with general service time distribution of both primary and secondary connections, multiple interruptions and transmission delay resulting from the appearance of primary connections. Then, we derive the close-expression of the extended data delivery and the system sojourn time in both staying and changing scenarios. In addition, based on analysis of spectrum handoff behaviors resulting from multiple interruptions caused by the appearance of the primary connections, we investigate the traffic-adaptive policy, by which the considered SU will optimally adjust its handoff spectrum policy. Moreover, we investigate the admissible region and provide the reference for designing the admission control rule for the arriving secondary connection requests. Finally, simulation results verify that our proposed analytical framework is reasonable and can provide the reference for executing the optimal spectrum handoff strategy and designing the admission control rule for the SU in cognitive radio networks.

  3. Analysis of Handoff Mechanisms in Mobile IP

    Science.gov (United States)

    Jayaraj, Maria Nadine Simonel; Issac, Biju; Haldar, Manas Kumar

    2011-06-01

    One of the most important challenges in mobile Internet Protocol (IP) is to provide service for a mobile node to maintain its connectivity to network when it moves from one domain to another. IP is responsible for routing packets across network. The first major version of IP is the Internet Protocol version 4 (IPv4). It is one of the dominant protocols relevant to wireless network. Later a newer version of IP called the IPv6 was proposed. Mobile IPv6 is mainly introduced for the purpose of mobility. Mobility management enables network to locate roaming nodes in order to deliver packets and maintain connections with them when moving into new domains. Handoff occurs when a mobile node moves from one network to another. It is a key factor of mobility because a mobile node can trigger several handoffs during a session. This paper briefly explains on mobile IP and its handoff issues, along with the drawbacks of mobile IP.

  4. Handoff algorithm for mobile satellite systems with ancillary terrestrial component

    KAUST Repository

    Sadek, Mirette

    2012-06-01

    This paper presents a locally optimal handoff algorithm for integrated satellite/ground communication systems. We derive the handoff decision function and present the results in the form of tradeoff curves between the number of handoffs and the number of link degradation events in a given distance covered by the mobile user. This is a practical receiver-controlled handoff algorithm that optimizes the handoff process from a user perspective based on the received signal strength rather than from a network perspective. © 2012 IEEE.

  5. Handoff Triggering and Network Selection Algorithms for Load-Balancing Handoff in CDMA-WLAN Integrated Networks

    Directory of Open Access Journals (Sweden)

    Khalid Qaraqe

    2008-10-01

    Full Text Available This paper proposes a novel vertical handoff algorithm between WLAN and CDMA networks to enable the integration of these networks. The proposed vertical handoff algorithm assumes a handoff decision process (handoff triggering and network selection. The handoff trigger is decided based on the received signal strength (RSS. To reduce the likelihood of unnecessary false handoffs, the distance criterion is also considered. As a network selection mechanism, based on the wireless channel assignment algorithm, this paper proposes a context-based network selection algorithm and the corresponding communication algorithms between WLAN and CDMA networks. This paper focuses on a handoff triggering criterion which uses both the RSS and distance information, and a network selection method which uses context information such as the dropping probability, blocking probability, GoS (grade of service, and number of handoff attempts. As a decision making criterion, the velocity threshold is determined to optimize the system performance. The optimal velocity threshold is adjusted to assign the available channels to the mobile stations. The optimal velocity threshold is adjusted to assign the available channels to the mobile stations using four handoff strategies. The four handoff strategies are evaluated and compared with each other in terms of GOS. Finally, the proposed scheme is validated by computer simulations.

  6. Handoff Triggering and Network Selection Algorithms for Load-Balancing Handoff in CDMA-WLAN Integrated Networks

    Directory of Open Access Journals (Sweden)

    Kim Jang-Sub

    2008-01-01

    Full Text Available This paper proposes a novel vertical handoff algorithm between WLAN and CDMA networks to enable the integration of these networks. The proposed vertical handoff algorithm assumes a handoff decision process (handoff triggering and network selection. The handoff trigger is decided based on the received signal strength (RSS. To reduce the likelihood of unnecessary false handoffs, the distance criterion is also considered. As a network selection mechanism, based on the wireless channel assignment algorithm, this paper proposes a context-based network selection algorithm and the corresponding communication algorithms between WLAN and CDMA networks. This paper focuses on a handoff triggering criterion which uses both the RSS and distance information, and a network selection method which uses context information such as the dropping probability, blocking probability, GoS (grade of service, and number of handoff attempts. As a decision making criterion, the velocity threshold is determined to optimize the system performance. The optimal velocity threshold is adjusted to assign the available channels to the mobile stations. The optimal velocity threshold is adjusted to assign the available channels to the mobile stations using four handoff strategies. The four handoff strategies are evaluated and compared with each other in terms of GOS. Finally, the proposed scheme is validated by computer simulations.

  7. Nurses' views of patient handoffs in Japanese hospitals

    DEFF Research Database (Denmark)

    Gu, Xiuzhu; Andersen, Henning Boje; Madsen, Marlene Dyrløv

    2012-01-01

    Staff perceptions of risks associated with patient handoffs were investigated in a survey of nurses in 6 Japanese hospitals. A total of 1462 valid responses were collected from nurses with an overall response rate of 74%. Respondents are moderately satisfied with the transfer of information and r...... and responsibility during handoffs. However, the handoff system was identified as immature. Hospital, work setting, and work experience affected nurses' views of handoff quality. Strategies for improving patient handoffs in Japan are proposed.......Staff perceptions of risks associated with patient handoffs were investigated in a survey of nurses in 6 Japanese hospitals. A total of 1462 valid responses were collected from nurses with an overall response rate of 74%. Respondents are moderately satisfied with the transfer of information...

  8. A Reinforcement Sensor Embedded Vertical Handoff Controller for Vehicular Heterogeneous Wireless Networks

    Directory of Open Access Journals (Sweden)

    Lin Ma

    2013-11-01

    Full Text Available Vehicular communication platforms that provide real-time access to wireless networks have drawn more and more attention in recent years. IEEE 802.11p is the main radio access technology that supports communication for high mobility terminals, however, due to its limited coverage, IEEE 802.11p is usually deployed by coupling with cellular networks to achieve seamless mobility. In a heterogeneous cellular/802.11p network, vehicular communication is characterized by its short time span in association with a wireless local area network (WLAN. Moreover, for the media access control (MAC scheme used for WLAN, the network throughput dramatically decreases with increasing user quantity. In response to these compelling problems, we propose a reinforcement sensor (RFS embedded vertical handoff control strategy to support mobility management. The RFS has online learning capability and can provide optimal handoff decisions in an adaptive fashion without prior knowledge. The algorithm integrates considerations including vehicular mobility, traffic load, handoff latency, and network status. Simulation results verify that the proposed algorithm can adaptively adjust the handoff strategy, allowing users to stay connected to the best network. Furthermore, the algorithm can ensure that RSUs are adequate, thereby guaranteeing a high quality user experience.

  9. Patient Handoffs: Is Cross Cover or Night Shift Better?

    Science.gov (United States)

    Higgins, Alanna; Brannen, Melissa L; Heiman, Heather L; Adler, Mark D

    2017-06-01

    Studies show singular handoffs between health care providers to be risky. Few describe sequential handoffs or compare handoffs from different provider types. We investigated the transfer of information across 2 handoffs using a piloted survey instrument. We compared cross-cover (every fourth night call) with dedicated night-shift residents. Surveys assessing provider knowledge of hospitalized patients were administered to pediatric residents. Primary teams were surveyed about their handoff upon completion of daytime coverage of a patient. Night-shift or cross-covering residents were surveyed about their handoff of the same patient upon completion of overnight coverage. Pediatric hospitalists rated the consistency of information between the surveys. Absolute difference was calculated between the 2 providers' rating of a patient's (a) complexity and (b) illness severity. Scores were compared across provider type. Fifty-nine complete handoff pairs were obtained. Fourteen and 45 handoff surveys were completed by a cross-covering and a night-shift provider, respectively. There was no significant difference in information consistency between primary and night-shift (median, 4.0; interquartile range [IQR], 3-4) versus primary and cross-covering providers (median, 4.0; IQR, 3-4). There was no significant difference in median patient complexity ratings (night shift, 3.0; IQR, 1-5, versus cross cover, 3.5; IQR, 1-5) or illness severity ratings (night shift, 2.0; IQR, 1-4, versus cross-cover, 3.0; IQR, 1-6) when comparing provider types giving a handoff. We did not find a difference in physicians' transfer of information during 2 handoffs among providers taking traditional call or on night shift. Development of tools to measure handoff consistency is needed.

  10. Late time phase transition as dark energy

    Indian Academy of Sciences (India)

    Abstract. We show that the dark energy field can naturally be described by the scalar condensates of a non-abelian gauge group. This gauge group is unified with the standard model gauge groups and it has a late time phase transition. The small phase transition explains why the positive acceleration of the universe is ...

  11. Assessment of a Brief Handoff Skills Workshop for Incoming Interns: Do past Handoff Experiences Impact Training Outcomes?

    Directory of Open Access Journals (Sweden)

    Christopher J. Smith

    2015-01-01

    Full Text Available Background Patient care handoffs are a core professional activity that incoming interns are expected to perform without direct supervision upon starting residency, yet training in medical schools is inconsistent. Objective To implement a brief handoff communication workshop for incoming interns and determine whether learner-level determinants were associated with differences in training outcomes. Methods We conducted a one-hour interactive handoff skills workshop for all incoming interns at a Midwestern academic medical center. We performed paired pre/post-intervention assessments of participants' attitudes and ability to perform representative handoff skills. The results were analyzed in aggregate and based upon participants' prior handoff experiences using Wilcoxon signed-rank test. Results Ninety-nine of 108 interns (91.7% completed both pre- and post-surveys. There was significant improvement in all 10 attitude-based questions ( P ≤ 0.014 for all and on the skills assessment (1.07 vs 2.16 on 0–4 point scale, SD 1.25, P ≤ 0.001. Results remained significant regardless of prior training, number of handoffs observed, number of handoffs performed, medical school, or residency discipline. Conclusion A brief interactive workshop for incoming interns can improve participants' confidence and performance of basic handoff skills, regardless of previous training or experience.

  12. Development of a Nursing Handoff Tool: A Web-Based Application to Enhance Patient Safety

    OpenAIRE

    Goldsmith, Denise; Boomhower, Marc; Lancaster, Diane R.; Antonelli, Mary; Kenyon, Mary Anne Murphy; Benoit, Angela; Chang, Frank; Dykes, Patricia C.

    2010-01-01

    Dynamic and complex clinical environments present many challenges for effective communication among health care providers. The omission of accurate, timely, easily accessible vital information by health care providers significantly increases risk of patient harm and can have devastating consequences for patient care. An effective nursing handoff supports the standardized transfer of accurate, timely, critical patient information, as well as continuity of care and treatment, resulting in enhan...

  13. A search for transit timing variation

    Directory of Open Access Journals (Sweden)

    Kramm U.

    2011-02-01

    Full Text Available Photometric follow-ups of transiting exoplanets (TEPs may lead to discoveries of additional, less massive bodies in extrasolar systems. This is possible by detecting and then analysing variations in transit timing of transiting exoplanets. In 2009 we launched an international observing campaign, the aim of which is to detect and characterise signals of transit timing variation (TTV in selected TEPs. The programme is realised by collecting data from 0.6-2.2-m telescopes spread worldwide at different longitudes. We present our observing strategy and summarise first results for WASP-3b with evidence for a 15 Earth-mass perturber in an outer 2:1 orbital resonance.

  14. Late-time cosmological phase transitions

    International Nuclear Information System (INIS)

    Schramm, D.N.

    1990-11-01

    It is shown that the potential galaxy formation and large-scale structure problems of objects existing at high redshifts (Z approx-gt 5), structures existing on scales of 100M pc as well as velocity flows on such scales, and minimal microwave anisotropies (ΔT/T) approx-lt 10 -5 can be solved if the seeds needed to generate structure form in a vacuum phase transition after decoupling. It is argued that the basic physics of such a phase transition is no more exotic than that utilized in the more traditional GUT scale phase transitions, and that, just as in the GUT case, significant random gaussian fluctuations and/or topological defects can form. Scale lengths of ∼100M pc for large-scale structure as well as ∼1 M pc for galaxy formation occur naturally. Possible support for new physics that might be associated with such a late-time transition comes from the preliminary results of the SAGE solar neutrino experiment, implying neutrino flavor mixing with values similar to those required for a late-time transition. It is also noted that a see-saw model for the neutrino masses might also imply a tau neutrino mass that is an ideal hot dark matter candidate. However, in general either hot or cold dark matter can be consistent with a late-time transition. 47 refs., 2 figs

  15. A vertical handoff scheme based on adaptive period

    Directory of Open Access Journals (Sweden)

    Li Yang

    2017-08-01

    Full Text Available This paper presents a periodic adaptive vertical handoff scheme.In the phase of handoff initiation,the mobile terminal will adjust the interfaces activating interval to scan the potential new wireless signals according to the Received Signals Strength.In the phase of handoff decision,multiple attribute judgment method are adopted to judge the comprehensive perfomance of each network.The simulation shows that the proposed scheme can discover new wireless networks access the network that has the best comprehensive performance saving consumed power.

  16. Verifying duration properties of timed transition systems

    DEFF Research Database (Denmark)

    Liu, Zhiming; Ravn, Anders P.; Li, Xiaoshan

    1998-01-01

    This paper proposes a method for formal real-time systems development:Requirements and high level design decisions are time interval properties and are therefore specified in the Duration Calculus (DC), while implementations are described bytimed transition systems (TTS). A link from implementati...

  17. Orocaecal transit time in Duchenne muscular dystrophy.

    OpenAIRE

    Korman, S H; Bar-Oz, B; Granot, E; Meyer, S

    1991-01-01

    Smooth muscle degeneration may occur in Duchenne muscular dystrophy. We measured fasting orocaecal transit time in patients with advanced Duchenne muscular dystrophy and other muscular dystrophies and in healthy controls. No significant differences were found. In contrast to reports of gastric hypomotility in Duchenne muscular dystrophy, we found no evidence of impaired small intestinal motility.

  18. Modeling and Performance Analysis for Cell Access and Handoff Schemes in Two-Tier Cellular Networks

    Directory of Open Access Journals (Sweden)

    Kyungkoo Jun

    2014-01-01

    Full Text Available We investigate the effects of handoff on system performance in two-tier cellular networks. Two of the main performance metrics are new call blocking probability and handoff drop rate. We develop analytical models to evaluate the performance of two different handoff schemes. One scheme considers only femto-to-macrocell handoff while the other is bidirectional including macro-to-femtocell handoff. Our model is more elaborate than existing ones which have not considered the mobility of mobile stations. Numerical results show that the bidirectional scheme performs better than the femto-to-macrocell handoff as it achieves lower blocking probability and drop rate.

  19. Beam induced transit time signals at SPEAR

    International Nuclear Information System (INIS)

    McConnell, R.A.

    1975-01-01

    Beam induced signals at frequencies related to inter-cavity transit times have been detected at SPEAR. Whether this effect enters significantly into beam instabilities has not yet been determined. Preliminary experiments suggest that under certain conditions at low energy (1.5 GeV) , when μ/sub s/, passes through one of the transit time resonances, some current is lost. Care must be taken, however, not to confuse this effect, if it exists, with synchrobetatron resonances and with an as yet unexplained vertical instability in SPEAR. At high energy (3.7 GeV), no effect has been shown to exist, though detectable signals are present. 2 refs., 2 tabs

  20. Linking age, survival, and transit time distributions

    Science.gov (United States)

    Calabrese, Salvatore; Porporato, Amilcare

    2015-10-01

    Although the concepts of age, survival, and transit time have been widely used in many fields, including population dynamics, chemical engineering, and hydrology, a comprehensive mathematical framework is still missing. Here we discuss several relationships among these quantities by starting from the evolution equation for the joint distribution of age and survival, from which the equations for age and survival time readily follow. It also becomes apparent how the statistical dependence between age and survival is directly related to either the age dependence of the loss function or the survival-time dependence of the input function. The solution of the joint distribution equation also allows us to obtain the relationships between the age at exit (or death) and the survival time at input (or birth), as well as to stress the symmetries of the various distributions under time reversal. The transit time is then obtained as a sum of the age and survival time, and its properties are discussed along with the general relationships between their mean values. The special case of steady state case is analyzed in detail. Some examples, inspired by hydrologic applications, are presented to illustrate the theory with the specific results. This article was corrected on 11 Nov 2015. See the end of the full text for details.

  1. Impact of electronic medical record integration of a handoff tool on sign-out in a newborn intensive care unit

    Science.gov (United States)

    Palma, JP; Sharek, PJ; Longhurst, CA

    2016-01-01

    Objective To evaluate the impact of integrating a handoff tool into the electronic medical record (EMR) on sign-out accuracy, satisfaction and workflow in a neonatal intensive care unit (NICU). Study Design Prospective surveys of neonatal care providers in an academic children’s hospital 1 month before and 6 months following EMR integration of a standalone Microsoft Access neonatal handoff tool. Result Providers perceived sign-out information to be somewhat or very accurate at a rate of 78% with the standalone handoff tool and 91% with the EMR-integrated tool (P < 0.01). Before integration of neonatal sign-out into the EMR, 35% of providers were satisfied with the process of updating sign-out information and 71% were satisfied with the printed sign-out document; following EMR integration, 92% of providers were satisfied with the process of updating sign-out information (P < 0.01) and 98% were satisfied with the printed sign-out document (P < 0.01). Neonatal care providers reported spending a median of 11 to 15 min/day updating the standalone sign-out and 16 to 20 min/day updating the EMR-integrated sign-out (P = 0.026). The median percentage of total sign-out preparation time dedicated to transcribing information from the EMR was 25 to 49% before and <25% after EMR integration of the handoff tool (P < 0.01). Conclusion Integration of a NICU-specific handoff tool into an EMR resulted in improvements in perceived sign-out accuracy, provider satisfaction and at least one aspect of workflow. PMID:21273990

  2. Energy scope of handoff strategies in macro-femtocell environments

    KAUST Repository

    Leon, Jaime

    2012-06-01

    Energy consumption in downlink mode is becoming an important topic as cellular communications grow into a large scale enterprise. The search for high rates keeping energy constraints low has put forward the idea that cells with smaller size may improve not only the capacity of the network, but also reduce the amount of energy that is needed to achieve such capacities. When using heterogeneous networks, users can be encouraged to handoff to a femtocell, that offers better capacity per unit energy spent, by means of different handoff strategies. These strategies may also improve the energy use of the network if the handoff priority is given to both, capacity, and energy use. © 2012 IEEE.

  3. Transit-time instability in Hall thrusters

    International Nuclear Information System (INIS)

    Barral, Serge; Makowski, Karol; Peradzynski, Zbigniew; Dudeck, Michel

    2005-01-01

    Longitudinal waves characterized by a phase velocity of the order of the velocity of ions have been recurrently observed in Hall thruster experiments and simulations. The origin of this so-called ion transit-time instability is investigated with a simple one-dimensional fluid model of a Hall thruster discharge in which cold ions are accelerated between two electrodes within a quasineutral plasma. A short-wave asymptotics applied to linearized equations shows that plasma perturbations in such a device consist of quasineutral ion acoustic waves superimposed on a background standing wave generated by discharge current oscillations. Under adequate circumstances and, in particular, at high ionization levels, acoustic waves are amplified as they propagate, inducing strong perturbation of the ion density and velocity. Responding to the subsequent perturbation of the column resistivity, the discharge current generates a standing wave, the reflection of which sustains the generation of acoustic waves at the inlet boundary. A calculation of the frequency and growth rate of this resonance mechanism for a supersonic ion flow is proposed, which illustrates the influence of the ionization degree on their onset and the approximate scaling of the frequency with the ion transit time. Consistent with experimental reports, the traveling wave can be observed on plasma density and velocity perturbations, while the plasma potential ostensibly oscillates in phase along the discharge

  4. Real-time subway information for improving transit ridership.

    Science.gov (United States)

    2016-08-01

    In recent years, the standardization of transit schedule information has yielded a dramatic increase in the accessibility of computerized transit schedules and given rise to real-time service schedules. Two such real-time service schedules are the Ge...

  5. Chalk Catchment Transit Time: Unresolved Issues

    Energy Technology Data Exchange (ETDEWEB)

    Darling, W. G.; Gooddy, D. C. [British Geological Survey, Crowmarsh Gifford, Wallingford, Oxfordshire (United Kingdom); Barker, J. A. [School of Civil Engineering and the Environment, University of Southampton, Southampton (United Kingdom); Robinson, M. [Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford, Oxfordshire (United Kingdom)

    2013-07-15

    The mean transit time (MTT) of a catchment is the average residence time of water from rainfall to river outflow at the foot of the catchment. As such, MTT has important water quality as well as resource implications. Many catchments worldwide have been measured for MTT using environmental isotopes, yet the Chalk, an important aquifer in NW Europe, has received little attention in this regard. The catchment of the River Lambourn in southern England has been intermittently studied since the 1960s using isotopic methods. A tritium peak measured in the river during the 1970s indicates an apparent MTT of {approx}15 years, but the thick unsaturated zone (average {approx}50 m) of the catchment suggests that the MTT should be much greater because of the average downward movement through the Chalk of {approx}1 m/a consistently indicated by tritium and other tracers. Recent work in the catchment using SF{sub 6} as a residence time indicator has given groundwater ages in the narrow range 11-18 yrs, apparently supporting the river tritium data but in conflict with the unsaturated zone data even allowing for a moderate proportion of rapid bypass flow. The MTT of the catchment remains unresolved for the time being. (author)

  6. A Location-Aware Vertical Handoff Algorithm for Hybrid Networks

    KAUST Repository

    Mehbodniya, Abolfazl

    2010-07-01

    One of the main objectives of wireless networking is to provide mobile users with a robust connection to different networks so that they can move freely between heterogeneous networks while running their computing applications with no interruption. Horizontal handoff, or generally speaking handoff, is a process which maintains a mobile user\\'s active connection as it moves within a wireless network, whereas vertical handoff (VHO) refers to handover between different types of networks or different network layers. Optimizing VHO process is an important issue, required to reduce network signalling and mobile device power consumption as well as to improve network quality of service (QoS) and grade of service (GoS). In this paper, a VHO algorithm in multitier (overlay) networks is proposed. This algorithm uses pattern recognition to estimate user\\'s position, and decides on the handoff based on this information. For the pattern recognition algorithm structure, the probabilistic neural network (PNN) which has considerable simplicity and efficiency over existing pattern classifiers is used. Further optimization is proposed to improve the performance of the PNN algorithm. Performance analysis and comparisons with the existing VHO algorithm are provided and demonstrate a significant improvement with the proposed algorithm. Furthermore, incorporating the proposed algorithm, a structure is proposed for VHO from the medium access control (MAC) layer point of view. © 2010 ACADEMY PUBLISHER.

  7. FTA real-time transit information assessment : white paper on literature review of real-time transit information systems.

    Science.gov (United States)

    Real-time transit information systems are key technology applications within the transit industry designed to provide better customer service by disseminating timely and accurate information. Riders use this information to make various decisions abou...

  8. Description of web-enhanced virtual character simulation system to standardize patient hand-offs.

    Science.gov (United States)

    Filichia, Lori; Halan, Shivashankar; Blackwelder, Ethan; Rossen, Brent; Lok, Benjamin; Korndorffer, James; Cendan, Juan

    2011-04-01

    The 80-h work week has increased discontinuity of patient care resulting in reports of increased medication errors and preventable adverse events. Graduate medical programs are addressing these shortcomings in a number of ways. We have developed a computer simulation platform called the Virtual People Factory (VPF), which allows us to capture and simulate the dialogue between a real user and a virtual character. We have converted the system to reflect a physician in the process of "checking-out" a patient to a covering physician. The responses are tracked and matched to educator-defined information termed "discoveries." Our proof of concept represented a typical post-operative patient with tachycardia. The system is web enabled. So far, 26 resident users at two institutions have completed the module. The critical discovery of tachycardia was identified by 62% of users. Residents spend 85% of the time asking intraoperative, postoperative, and past medical history questions. The system improves over time such that there is a near-doubling of questions that yield appropriate answers between users 13 and 22. Users who identified the virtual patient's underlying tachycardia expressed more concern and were more likely to order further testing for the patient in a post-module questionnaire (P = 0.13 and 0.08, respectively, NS). The VPF system can capture unique details about the hand-off interchange. The system improves with sequential users such that better matching of questions and answers occurs within the initial 25 users allowing rapid development of new modules. A catalog of hand-off modules could be easily developed. Wide-scale web-based deployment was uncomplicated. Identification of the critical findings appropriately translated to user concern for the patient though our series was too small to reach significance. Performance metrics based on the identification of critical discoveries could be used to assess readiness of the user to carry off a successful hand-off

  9. A systematic review of nurses' inter-shift handoff reports in acute care hospitals.

    Science.gov (United States)

    Poletick, Eilleen B; Holly, Cheryl

    2010-01-01

    An inter-shift nursing handoff report is the exchange of patient care information for evidence-based nursing and midwifery from one nurse to another, and is a universal procedure used in hospitals to promote continuity of care. The objective of this review was to appraise and synthesize the best available qualitative evidence pertaining to the nursing handoff report at the time of shift change and make recommendations that can enhance the transfer of information between and among nurses, and by extension, improve patient care. The review considered qualitative studies that drew on the experiences of nurses at the time of inter-shift nursing handoff in acute care hospitals, and included designs such as phenomenology, grounded theory, narrative analysis, action research, ethnographic or cultural studies. The search strategy sought to find both published and unpublished research papers. An initial search of the Joanna Briggs Institute for Evidence-Based Nursing and Midwifery, the Cochrane Library, and PubMed's Clinical Inquiry/Find Systematic Review database was conducted. Following this, an extensive three stage search was conducted using PubMed, CINAHL, HealthStar, ScienceDirect, Dissertation Abstracts International, DARE, PsycINFO, BioMedCentral, TRIP, Pre-CINAHL, PsycARTICLES, Psychology and Behavioural Sciences Collection, ISI Current Contents, Science.gov, Web of Science/Web of Knowledge, Scirus.com website. Included was a hand search of reference lists of identified papers to capture all pertinent material as well as a search of relevant world wide websites and search engines, such as Google Scholar and the Virginia Henderson Library of Sigma Theta Tau International. Each paper was assessed independently, by two reviewers for methodological quality prior to inclusion in the review using the critical appraisal instrument QARI (Qualitative Assessment and Review Instrument) developed by the Joanna Briggs Institute for Evidence Based Nursing and Midwifery. A total

  10. Transit time corrected arterial spin labeling technique aids to overcome delayed transit time effect

    International Nuclear Information System (INIS)

    Yun, Tae Jin; Sohn, Chul-Ho; Yoo, Roh-Eul; Kang, Kyung Mi; Choi, Seung Hong; Kim, Ji-hoon; Park, Sun-Won; Hwang, Moonjung; Lebel, R.M.

    2018-01-01

    This study aimed to evaluate the usefulness of transit time corrected cerebral blood flow (CBF) maps based on multi-phase arterial spin labeling MR perfusion imaging (ASL-MRP). The Institutional Review Board of our hospital approved this retrospective study. Written informed consent was waived. Conventional and multi-phase ASL-MRPs and dynamic susceptibility contrast MR perfusion imaging (DSC-MRP) were acquired for 108 consecutive patients. Vascular territory-based volumes of interest were applied to CBF and time to peak (TTP) maps obtained from DSC-MRP and CBF maps obtained from conventional and multi-phase ASL-MRPs. The concordances between normalized CBF (nCBF) from DSC-MRP and nCBF from conventional and transition time corrected CBF maps from multi-phase ASL-MRP were evaluated using Bland-Altman analysis. In addition, the dependence of difference between nCBF (ΔnCBF) values obtained from DSC-MRP and conventional ASL-MRP (or multi-phase ASL-MRP) on TTP obtained from DSC-MRP was also analyzed using regression analysis. The values of nCBFs from conventional and multi-phase ASL-MRPs had lower values than nCBF based on DSC-MRP (mean differences, 0.08 and 0.07, respectively). The values of ΔnCBF were dependent on TTP values from conventional ASL-MRP technique (F = 5.5679, P = 0.0384). No dependency of ΔnCBF on TTP values from multi-phase ASL-MRP technique was revealed (F = 0.1433, P > 0.05). The use of transit time corrected CBF maps based on multi-phase ASL-MRP technique can overcome the effect of delayed transit time on perfusion maps based on conventional ASL-MRP. (orig.)

  11. Transit time corrected arterial spin labeling technique aids to overcome delayed transit time effect

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Tae Jin; Sohn, Chul-Ho; Yoo, Roh-Eul; Kang, Kyung Mi; Choi, Seung Hong; Kim, Ji-hoon [Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Park, Sun-Won [Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University Boramae Medical Center, Department of Radiology, Seoul (Korea, Republic of); Hwang, Moonjung [GE Healthcare Korea, Seoul (Korea, Republic of); Lebel, R.M. [GE Healthcare Canada, Calgary (Canada)

    2018-03-15

    This study aimed to evaluate the usefulness of transit time corrected cerebral blood flow (CBF) maps based on multi-phase arterial spin labeling MR perfusion imaging (ASL-MRP). The Institutional Review Board of our hospital approved this retrospective study. Written informed consent was waived. Conventional and multi-phase ASL-MRPs and dynamic susceptibility contrast MR perfusion imaging (DSC-MRP) were acquired for 108 consecutive patients. Vascular territory-based volumes of interest were applied to CBF and time to peak (TTP) maps obtained from DSC-MRP and CBF maps obtained from conventional and multi-phase ASL-MRPs. The concordances between normalized CBF (nCBF) from DSC-MRP and nCBF from conventional and transition time corrected CBF maps from multi-phase ASL-MRP were evaluated using Bland-Altman analysis. In addition, the dependence of difference between nCBF (ΔnCBF) values obtained from DSC-MRP and conventional ASL-MRP (or multi-phase ASL-MRP) on TTP obtained from DSC-MRP was also analyzed using regression analysis. The values of nCBFs from conventional and multi-phase ASL-MRPs had lower values than nCBF based on DSC-MRP (mean differences, 0.08 and 0.07, respectively). The values of ΔnCBF were dependent on TTP values from conventional ASL-MRP technique (F = 5.5679, P = 0.0384). No dependency of ΔnCBF on TTP values from multi-phase ASL-MRP technique was revealed (F = 0.1433, P > 0.05). The use of transit time corrected CBF maps based on multi-phase ASL-MRP technique can overcome the effect of delayed transit time on perfusion maps based on conventional ASL-MRP. (orig.)

  12. Implementing standardized, inter-unit communication in an international setting: handoff of patients from emergency medicine to internal medicine.

    Science.gov (United States)

    Balhara, Kamna S; Peterson, Susan M; Elabd, Mohamed Moheb; Regan, Linda; Anton, Xavier; Al-Natour, Basil Ali; Hsieh, Yu-Hsiang; Scheulen, James; Stewart de Ramirez, Sarah A

    2018-04-01

    Standardized handoffs may reduce communication errors, but research on handoff in community and international settings is lacking. Our study at a community hospital in the United Arab Emirates characterizes existing handoff practices for admitted patients from emergency medicine (EM) to internal medicine (IM), develops a standardized handoff tool, and assesses its impact on communication and physician perceptions. EM physicians completed a survey regarding handoff practices and expectations. Trained observers utilized a checklist based on the Systems Engineering Initiative for Patient Safety model to observe 40 handoffs. EM and IM physicians collaboratively developed a written tool encouraging bedside handoff of admitted patients. After the intervention, surveys of EM physicians and 40 observations were subsequently repeated. 77.5% of initial observed handoffs occurred face-to-face, with 42.5% at bedside, and in four different languages. Most survey respondents considered face-to-face handoff ideal. Respondents noted 9-13 patients suffering harm due to handoff in the prior month. After handoff tool implementation, 97.5% of observed handoffs occurred face-to-face (versus 77.5%, p = 0.014), with 82.5% at bedside (versus 42.5%, p face-to-face and bedside handoff, positively impacted workflow, and increased perceptions of safety by EM physicians in an international, non-academic setting. Our three-step approach can be applied towards developing standardized, context-specific inter-specialty handoff in a variety of settings.

  13. Traffic-Adaptive Proactive Sp ectrum Handoff Strategy for Graded Secondary Users in Cognitive Radio Networks

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lei; SONG Tiecheng; WU Ming; BAO Xu; GUO Jie; HU Jing

    2015-01-01

    In order to meet diff erent delay require-ments of various communication services in Cognitive ra-dio (CR) networks, Secondary users (SUs) are divided into two classes according to the priority of accessing to spec-trum in this paper. Based on the proactive spectrum hand-off scheme, the Preemptive resume priority (PRP) M/G/1 queueing is used to characterize multiple spectrum hand-off s under two diff erent spectrum handoff strategies. The traffic-adaptive spectrum handoff strategy is proposed for graded SUs so as to minimize the average cumulative hand-off delay. Simulation results not only verify that our theo-retical analysis is valid, but also show that the strategy we proposed can reduce the average cumulative handoff delay evidently. The eff ect of service rate on the proposed spec-trum switching point and the admissible access region are provided.

  14. TRANSIT TIMING OBSERVATIONS FROM KEPLER. VIII. CATALOG OF TRANSIT TIMING MEASUREMENTS OF THE FIRST TWELVE QUARTERS

    Energy Technology Data Exchange (ETDEWEB)

    Mazeh, Tsevi; Nachmani, Gil; Holczer, Tomer; Sokol, Gil [School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of Chicago, 5640 Ellis Ave., Chicago, IL 60637 (United States); Ford, Eric B.; Ragozzine, Darin [Astronomy Department, University of Florida, Gainesville, FL 32111 (United States); Sanchis-Ojeda, Roberto [Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Rowe, Jason F.; Lissauer, Jack J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Zucker, Shay [Department of Geophysical, Atmospheric and Planetary Sciences, Raymond and Beverly Sackler Faculty of Exact Sciences Tel Aviv University, 69978 Tel Aviv (Israel); Agol, Eric [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Carter, Joshua A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Quintana, Elisa V. [SETI Institute, 189 Bernardo Ave, Suite 100, Mountain View, CA 94043 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Welsh, William [Astronomy Department, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182 (United States)

    2013-10-01

    Following the works of Ford et al. and Steffen et al. we derived the transit timing of 1960 Kepler objects of interest (KOIs) using the pre-search data conditioning light curves of the first twelve quarters of the Kepler data. For 721 KOIs with large enough signal-to-noise ratios, we obtained also the duration and depth of each transit. The results are presented as a catalog for the community to use. We derived a few statistics of our results that could be used to indicate significant variations. Including systems found by previous works, we have found 130 KOIs that showed highly significant times of transit variations (TTVs) and 13 that had short-period TTV modulations with small amplitudes. We consider two effects that could cause apparent periodic TTV—the finite sampling of the observations and the interference with the stellar activity, stellar spots in particular. We briefly discuss some statistical aspects of our detected TTVs. We show that the TTV period is correlated with the orbital period of the planet and with the TTV amplitude.

  15. Constructing ordinal partition transition networks from multivariate time series.

    Science.gov (United States)

    Zhang, Jiayang; Zhou, Jie; Tang, Ming; Guo, Heng; Small, Michael; Zou, Yong

    2017-08-10

    A growing number of algorithms have been proposed to map a scalar time series into ordinal partition transition networks. However, most observable phenomena in the empirical sciences are of a multivariate nature. We construct ordinal partition transition networks for multivariate time series. This approach yields weighted directed networks representing the pattern transition properties of time series in velocity space, which hence provides dynamic insights of the underling system. Furthermore, we propose a measure of entropy to characterize ordinal partition transition dynamics, which is sensitive to capturing the possible local geometric changes of phase space trajectories. We demonstrate the applicability of pattern transition networks to capture phase coherence to non-coherence transitions, and to characterize paths to phase synchronizations. Therefore, we conclude that the ordinal partition transition network approach provides complementary insight to the traditional symbolic analysis of nonlinear multivariate time series.

  16. Transit timing observations from Kepler. V. Transit timing variation candidates in the first sixteen months from polynomial models

    DEFF Research Database (Denmark)

    Ford, E.B.; Ragozzine, D.; Holman, M.J.

    2012-01-01

    Transit timing variations provide a powerful tool for confirming and characterizing transiting planets, as well as detecting non-transiting planets. We report the results of an updated transit timing variation (TTV) analysis for 1481 planet candidates based on transit times measured during...... that several of these planet candidates could be confirmed and perhaps characterized with more detailed TTV analyses using publicly available Kepler observations. For many others, Kepler has observed a long-term TTV trend, but an extended Kepler mission will be required to characterize the system via TTVs. We...

  17. Performance of a cognitive load inventory during simulated handoffs: Evidence for validity.

    Science.gov (United States)

    Young, John Q; Boscardin, Christy K; van Dijk, Savannah M; Abdullah, Ruqayyah; Irby, David M; Sewell, Justin L; Ten Cate, Olle; O'Sullivan, Patricia S

    2016-01-01

    Advancing patient safety during handoffs remains a public health priority. The application of cognitive load theory offers promise, but is currently limited by the inability to measure cognitive load types. To develop and collect validity evidence for a revised self-report inventory that measures cognitive load types during a handoff. Based on prior published work, input from experts in cognitive load theory and handoffs, and a think-aloud exercise with residents, a revised Cognitive Load Inventory for Handoffs was developed. The Cognitive Load Inventory for Handoffs has items for intrinsic, extraneous, and germane load. Students who were second- and sixth-year students recruited from a Dutch medical school participated in four simulated handoffs (two simple and two complex cases). At the end of each handoff, study participants completed the Cognitive Load Inventory for Handoffs, Paas' Cognitive Load Scale, and one global rating item for intrinsic load, extraneous load, and germane load, respectively. Factor and correlational analyses were performed to collect evidence for validity. Confirmatory factor analysis yielded a single factor that combined intrinsic and germane loads. The extraneous load items performed poorly and were removed from the model. The score from the combined intrinsic and germane load items associated, as predicted by cognitive load theory, with a commonly used measure of overall cognitive load (Pearson's r = 0.83, p load during handoffs may be measured via a self-report measure. Additional work is required to develop an adequate measure of extraneous load.

  18. The Research on Handoff Strategy in Beyond 3G Wireless Networks

    Institute of Scientific and Technical Information of China (English)

    CUI Hong-yan; TIAN Hui; XU Hai-bo; ZHANG Ping

    2006-01-01

    One of the major challenges for beyond third generation mobile systems is efficient mobility management. This paper proposes a distributed dynamic management scheme of handoff based on B3G networks. This .scheme can reduce the co.st of update signalling and transmitting packets, and improve the system capability. In this .scheme, the dynamic building network approach is adopted to deduce the update signalling cost. We implement the distributed dynamic management scheme of handoff in a simulation platform and compare its performance with that of general centralized handoff management schemes. Our simulation results indicate that our .scheme is capable of reducing the update handoff latency, and enhancing the performance.

  19. Call Admission Scheme for Multidimensional Traffic Assuming Finite Handoff User

    Directory of Open Access Journals (Sweden)

    Md. Baitul Al Sadi

    2017-01-01

    Full Text Available Usually, the number of users within a cell in a mobile cellular network is considered infinite; hence, M/M/n/k model is appropriate for new originated traffic, but the number of ongoing calls around a cell is always finite. Hence, the traffic model of handoff call will be M/M/n/k/N. In this paper, a K-dimensional traffic model of a mobile cellular network is proposed using the combination of limited and unlimited users case. A new call admission scheme (CAS is proposed based on both thinning scheme and fading condition. The fading condition of the wireless channel access to a handoff call is prioritized compared to newly originated calls.

  20. Bandwidth Reservation Using Velocity and Handoff Statistics for Cellular Networks

    Institute of Scientific and Technical Information of China (English)

    Chuan-Lin Zhang; Kam Yiu Lam; Wei-Jia Jia

    2006-01-01

    The percentages of blocking and forced termination rates as parameters representing quality of services (QoS)requirements are presented. The relation between the connection statistics of mobile users in a cell and the handoff number and new call number in next duration in each cell is explored. Based on the relation, statistic reservation tactics are raised.The amount of bandwidth for new calls and handoffs of each cell in next period is determined by using the strategy. Using this method can guarantee the communication system suits mobile connection request dynamic. The QoS parameters:forced termination rate and blocking rate can be maintained steadily though they may change with the offered load. Some numerical experiments demonstrate this is a practical method with affordable overhead.

  1. Modelo AHP-VIKOR para handoff espectral en redes de radio cognitiva

    Directory of Open Access Journals (Sweden)

    César Hernández

    2015-07-01

    Full Text Available This paper proposed a hybrid algorithm for spectrum allocation in cognitive radio networks based on two algorithms, analytical hierarchical process (AHP and multi-criteria optimization and compromise solution (VIKOR, for improving the performance of mobility spectrum of secondary users in cognitive radio networks. To evaluate the level of performance of the proposed algorithm, a comparative analysis between the proposed AHP-VIKOR, Grey Relational Analysis (GRA and a random allocation of spectrum (Random algorithm, is performed. The first two algorithms work with the same decision criteria: probability of channel availability, estimated time availability, signal-to-interference-plus-noise ratio and bandwidth. Unlike related work, benchmarking was validated through a trace of real spectral occupation data, captured in the GSM frequency band, which models the actual behavior of licensed users. For performance evaluation five metric were used, handoff failed average cumulative number, handoff average cumulative number, average bandwidth, delay and throughput average cumulative. The results of the comparative analysis with the other two algorithms show that the AHP-VIKOR algorithm proposed provides the best performance in spectral mobility.

  2. An Overview of Vertical Handoff Decision Algorithms in NGWNs and a new Scheme for Providing Optimized Performance in Heterogeneous Wireless Networks

    Directory of Open Access Journals (Sweden)

    Ionut BOSOANCA

    2011-01-01

    Full Text Available Because the increasingly development and use of wireless networks and mobile technologies, was implemented the idea that users of mobile terminals must have access in different wireless networks simultaneously. Therefore one of the main interest points of Next Generation Wireless Networks (NGWNs, refers to the ability to support wireless network access equipment to ensure a high rate of services between different wireless networks. To solve these problems it was necessary to have decision algorithms to decide for each user of mobile terminal, which is the best network at some point, for a service or a specific application that the user needs. Therefore to make these things, different algorithms use the vertical handoff technique. Below are presented a series of algorithms based on vertical handoff technique with a classification of the different existing vertical handoff decision strategies, which tries to solve these issues of wireless network selection at a given time for a specific application of an user. Based on our synthesis on vertical handoff decision strategies given below, we build our strategy based on solutions presented below, taking the most interesting aspect of each one.

  3. Relationship between functional elongated colonic transit time and constipation

    International Nuclear Information System (INIS)

    Xie Yuchang; Qian Xuequn; Zhang Genfu

    2002-01-01

    Objective: To retrospectively analyze the role of colonic transit test in diagnosis and aetiology of constipation. Methods: 87 cases of constipation diagnosed under Agachan scoring system and having completed transit test at least once were enrolled. All cases were divided into two groups: group A have normal colonic transit time, group B have extended colonic transit time. A comparison of the ratio of rectosigmoid transit by total colon (RRT) between group A and B. Result: 32 cases were enrolled in group A and 55 in group B. Low value of RRT was presented in 10 cases out of 32 in group A (31.3%), while in group B the abnormality was observed in 9 cases out of 55 (16.4%). A statistical difference between the two group was revealed by x 2 test (P < 0.01). Conclusion: Colonic transit test helps the confirming the aetiology of constipation, and the evaluation of rectosigmoid transit function is especially valuable

  4. Thermocouple correlation transit time flowmeter tests at WCL

    International Nuclear Information System (INIS)

    Lassahn, G.D.

    1976-11-01

    Scoping tests indicate the feasibility for using transit time flowmeters with thermocouple sensors in steam-water steady state flow. Conclusive results were not obtained. More conclusive results are expected from tests to be conducted in the semiscale facility with a redesigned transit time thermocouple sensor

  5. Regional gastrointestinal transit times in severe ulcerative colitis.

    Science.gov (United States)

    Haase, A M; Gregersen, T; Christensen, L A; Agnholt, J; Dahlerup, J F; Schlageter, V; Krogh, K

    2016-02-01

    Gastrointestinal (GI) dysmotility may present secondary to inflammatory bowel disease. The main aim of this study was to investigate GI motility in ulcerative colitis (UC) patients during severe disease activity. Twenty patients with severe UC were studied with a novel telemetric capsule system (3D-Transit) designed for minimally invasive, ambulatory assessment of total and regional GI transit times. Ten patients were available for follow-up during remission. Data were compared to those of 20 healthy subjects (HS). Total GI transit time was significantly longer in patients with severe UC (median 44.5 h [range 9.9-102.7 h]) than in HS (median 27.6 h [range 9.6-56.4 h]) (p = 0.032). Additionally, during severe UC, transit time was prolonged through the proximal colon (p = 0.003) and there were strong trends toward longer than normal small intestinal transit time (HS: median 4.9 h [range 3.4-8.3 h] vs severe UC patients: median 5.9 h [range 3.9-11.9 h]; p = 0.053) and colorectal transit times (HS: median 18.2 h [range 1.5-43.7] vs severe UC patients: median 34.9 h [range 0.4-90.9 h]; p = 0.056). Our data further indicate that total GI and colorectal transit times may be prolonged in UC during early remission. Total GI transit times are significantly prolonged during severe UC. © 2016 John Wiley & Sons Ltd.

  6. Radiocardiography of minimal transit times: a useful diagnostic procedure

    International Nuclear Information System (INIS)

    Schicha, H.; Vyska, K.; Becker, V.; Feinendegen, L.E.; Duesseldorf Univ., F.R. Germany)

    1975-01-01

    Contrary to mean transit times, minimal transit times are the differences between arrival times of an indicator. Arrival times in various cardiac compartments can be easily measured with radioisotopes and fast gamma cameras permitting data processing. This paper summarizes data selected from more than 1500 measurements made so far on normal individuals and patients with valvular heart disease, myocardial insufficiency, digitalis effect, atrial fibrillation, hypothyroidism, hyperthyroidism, effort-syndrome and coronary artery disease. (author)

  7. Effect of Handoff Skills Training for Students during the Medicine Clerkship: A Quasi-Randomized Study

    Science.gov (United States)

    Reyes, Juan A.; Greenberg, Larrie; Amdur, Richard; Gehring, James; Lesky, Linda G.

    2016-01-01

    Continuity is critical for safe patient care and its absence is associated with adverse outcomes. Continuity requires handoffs between physicians, but most published studies of educational interventions to improve handoffs have focused primarily on residents, despite interns expected to being proficient. The AAMC core entrustable activities for…

  8. Transition Icons for Time-Series Visualization and Exploratory Analysis.

    Science.gov (United States)

    Nickerson, Paul V; Baharloo, Raheleh; Wanigatunga, Amal A; Manini, Todd M; Tighe, Patrick J; Rashidi, Parisa

    2018-03-01

    The modern healthcare landscape has seen the rapid emergence of techniques and devices that temporally monitor and record physiological signals. The prevalence of time-series data within the healthcare field necessitates the development of methods that can analyze the data in order to draw meaningful conclusions. Time-series behavior is notoriously difficult to intuitively understand due to its intrinsic high-dimensionality, which is compounded in the case of analyzing groups of time series collected from different patients. Our framework, which we call transition icons, renders common patterns in a visual format useful for understanding the shared behavior within groups of time series. Transition icons are adept at detecting and displaying subtle differences and similarities, e.g., between measurements taken from patients receiving different treatment strategies or stratified by demographics. We introduce various methods that collectively allow for exploratory analysis of groups of time series, while being free of distribution assumptions and including simple heuristics for parameter determination. Our technique extracts discrete transition patterns from symbolic aggregate approXimation representations, and compiles transition frequencies into a bag of patterns constructed for each group. These transition frequencies are normalized and aligned in icon form to intuitively display the underlying patterns. We demonstrate the transition icon technique for two time-series datasets-postoperative pain scores, and hip-worn accelerometer activity counts. We believe transition icons can be an important tool for researchers approaching time-series data, as they give rich and intuitive information about collective time-series behaviors.

  9. Pharyngeal Pressure and Timing During Bolus Transit

    Science.gov (United States)

    Walczak, Chelsea C.; Jones, Corinne A.; McCulloch, Timothy M.

    2018-01-01

    Determining intrabolus pressure (IBP) at the upper esophageal sphincter (UES) and in the esophagus has given compelling evidence that IBP can be a predictor for swallowing dysfunction. Studies have looked most superiorly at the low hypopharynx region but there has been no inquiry into what IBP measures throughout the entire pharynx can tell us. We present a study to describe the pressures within and surrounding the moving bolus throughout the pharynx and into the UES. Simultaneous HRM and videofluoroscopy were performed in 10 healthy subjects swallowing ten 10 mL thin-liquid barium boluses. Three events surrounding bolus movement were tracked via videofluoroscopy, two additional events were found using manometric measures. As the bolus passes through the pharynx, low pressure is created at and below the head of the bolus. A modest pressure increase is seen as the bolus passes through the pharynx and finally, high pressure is observed at the bolus tail, followed by an even larger pressure generation of a clearance event. HRM allows for greater resolution in data collection in the pharynx and in this study, aided in identifying semi unique characteristics around the hypopharynx and the UES which are consistent with the complex anatomy of the regions and the transition of the UES from active closure to relaxed opening. In the future, additional studies designed to look at aged and diseased populations may lead to better understanding of disease etiology, and treatment options. PMID:27565155

  10. Reservoir theory, groundwater transit time distributions, and lumped parameter models

    International Nuclear Information System (INIS)

    Etcheverry, D.; Perrochet, P.

    1999-01-01

    The relation between groundwater residence times and transit times is given by the reservoir theory. It allows to calculate theoretical transit time distributions in a deterministic way, analytically, or on numerical models. Two analytical solutions validates the piston flow and the exponential model for simple conceptual flow systems. A numerical solution of a hypothetical regional groundwater flow shows that lumped parameter models could be applied in some cases to large-scale, heterogeneous aquifers. (author)

  11. Pemodelan Markov Switching Dengan Time-varying Transition Probability

    OpenAIRE

    Savitri, Anggita Puri; Warsito, Budi; Rahmawati, Rita

    2016-01-01

    Exchange rate or currency is an economic variable which reflects country's state of economy. It fluctuates over time because of its ability to switch the condition or regime caused by economic and political factors. The changes in the exchange rate are depreciation and appreciation. Therefore, it could be modeled using Markov Switching with Time-Varying Transition Probability which observe the conditional changes and use information variable. From this model, time-varying transition probabili...

  12. Transit time measurement of Juqueri river waters

    International Nuclear Information System (INIS)

    Plata Bedmar, E.; Garcia A, E.; Albuquerque, A.M. de; Sanchez, W.

    1975-01-01

    The time of travel of the Juqueri River water through the east branch of the Pirapora Reservoir was measured using radioactive tracers (6 Ci 131 I in Kl Solution). The changes in Juqueri River flow rate were also measured during the run. The center of mass of the radioactive cloud was used for the time of travel calculations. Six measurements of the Juqueri River flow rate were perfomed in different days, using the total count method. Fifty, millicuries of 131 I were used in each run. The results of time travel obtained under non-steady conditions, and their correction for steady state are also discussed

  13. TRANSIT TIMING OBSERVATIONS FROM KEPLER. V. TRANSIT TIMING VARIATION CANDIDATES IN THE FIRST SIXTEEN MONTHS FROM POLYNOMIAL MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Eric B. [Astronomy Department, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL 32111 (United States); Ragozzine, Darin; Holman, Matthew J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Rowe, Jason F.; Barclay, Thomas; Borucki, William J.; Bryson, Stephen T.; Caldwell, Douglas A.; Kinemuchi, Karen; Koch, David G.; Lissauer, Jack J.; Still, Martin; Tenenbaum, Peter [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Fabrycky, Daniel C. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Gautier, Thomas N. [Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA 91109 (United States); Ibrahim, Khadeejah A.; Uddin, Kamal [Orbital Sciences Corporation/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Kjeldsen, Hans, E-mail: eford@astro.ufl.edu [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); and others

    2012-09-10

    Transit timing variations provide a powerful tool for confirming and characterizing transiting planets, as well as detecting non-transiting planets. We report the results of an updated transit timing variation (TTV) analysis for 1481 planet candidates based on transit times measured during the first sixteen months of Kepler observations. We present 39 strong TTV candidates based on long-term trends (2.8% of suitable data sets). We present another 136 weaker TTV candidates (9.8% of suitable data sets) based on the excess scatter of TTV measurements about a linear ephemeris. We anticipate that several of these planet candidates could be confirmed and perhaps characterized with more detailed TTV analyses using publicly available Kepler observations. For many others, Kepler has observed a long-term TTV trend, but an extended Kepler mission will be required to characterize the system via TTVs. We find that the occurrence rate of planet candidates that show TTVs is significantly increased ({approx}68%) for planet candidates transiting stars with multiple transiting planet candidates when compared to planet candidates transiting stars with a single transiting planet candidate.

  14. The liner shipping berth scheduling problem with transit times

    DEFF Research Database (Denmark)

    Reinhardt, Line Blander; Plum, Christian E.M.; Pisinger, David

    2016-01-01

    In this paper speed optimization of an existing liner shipping network is solved by adjusting the port berth times. The objective is to minimize fuel consumption while retaining the customer transit times including the transhipment times. To avoid too many changes to the time table, changes of port...

  15. Gastric transit and small intestinal transit time and motility assessed by a magnet tracking system.

    Science.gov (United States)

    Worsøe, Jonas; Fynne, Lotte; Gregersen, Tine; Schlageter, Vincent; Christensen, Lisbet A; Dahlerup, Jens F; Rijkhoff, Nico J M; Laurberg, Søren; Krogh, Klaus

    2011-12-29

    Tracking an ingested magnet by the Magnet Tracking System MTS-1 (Motilis, Lausanne, Switzerland) is an easy and minimally-invasive method to assess gastrointestinal transit. The aim was to test the validity of MTS-1 for assessment of gastric transit time and small intestinal transit time, and to illustrate transit patterns detected by the system. A small magnet was ingested and tracked by an external matrix of 16 magnetic field sensors (4 × 4) giving a position defined by 5 coordinates (position: x, y, z, and angle: θ, φ). Eight healthy subjects were each investigated three times: (1) with a small magnet mounted on a capsule endoscope (PillCam); (2) with the magnet alone and the small intestine in the fasting state; and (3) with the magnet alone and the small intestine in the postprandial state. Experiment (1) showed good agreement and no systematic differences between MTS-1 and capsule endoscopy when assessing gastric transit (median difference 1 min; range: 0-6 min) and small intestinal transit time (median difference 0.5 min; range: 0-52 min). Comparing experiments (1) and (2) there were no systematic differences in gastric transit or small intestinal transit when using the magnet-PillCam unit and the much smaller magnetic pill. In experiments (2) and (3), short bursts of very fast movements lasting less than 5% of the time accounted for more than half the distance covered during the first two hours in the small intestine, irrespective of whether the small intestine was in the fasting or postprandial state. The mean contraction frequency in the small intestine was significantly lower in the fasting state than in the postprandial state (9.90 min-1 vs. 10.53 min-1) (p = 0.03). MTS-1 is reliable for determination of gastric transit and small intestinal transit time. It is possible to distinguish between the mean contraction frequency of small intestine in the fasting state and in the postprandial state.

  16. Implementation of mobile ip smooth handoff in wireless networks

    International Nuclear Information System (INIS)

    Kayastha, M.; Chowdhry, B.S.; Memon, A.R.

    2002-01-01

    This paper describes implementation of mobile IP services in two separate wireless LANs based on IEEE 802.11b standards, located in two distant buildings of a university campus. The purpose of the project was to achieve smooth hand-off when a mobile node moves between the two LANs. During our experimentation we have identified some of the limitation of IEEE 802.11b that affects mobile 1P smooth hand off. We have also proposed an algorithm to solve this problem when the mobility is within a limited number of separate wireless LANs. (author)

  17. Transitional Leadership: Leadership During Times of Transition, Key Principles, and Considerations for Success.

    Science.gov (United States)

    Norbash, Alexander

    2017-06-01

    To suggest a methodical approach for refining transitional management abilities, including empowerment of a growing leader, leading in an unfamiliar organization or leading in an organization that is changing. Management approaches based on the body of work dealing with leadership studies and transitions and dealing with leadership during times of transition and change management were consolidated and categorized. Transitional leaders can benefit from effective leadership training including defining and prospectively accruing necessary experiences and skills; strengthening information gathering skills; effectively self-assessing; valuing and implementing mentoring; formulating strategy; and communicating. A categorical approach to transitional leadership may be implemented through a systems-based and methodical approach to gaining the definable, and distinct sets of skills and abilities necessary for transitional leadership success. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  18. Piloting a Structured Practice Audit to Assess ACGME Milestones in Written Handoff Communication in Internal Medicine.

    Science.gov (United States)

    Martin, Shannon K; Farnan, Jeanne M; McConville, John F; Arora, Vineet M

    2015-06-01

    Written communication skills are integral to patient care handoffs. Residency programs require feasible assessment tools that provide timely formative and summative feedback, ideally linked to the Accreditation Council for Graduate Medical Education Milestones. We describe the use of 1 such tool-UPDATED-to assess written handoff communication skills in internal medicine interns. During 2012-2013, the authors piloted a structured practice audit at 1 academic institution to audit written sign-outs completed by 45 interns, using the UPDATED tool, which scores 7 aspects of sign-out communication linked to milestones. Intern sign-outs were audited by trained faculty members throughout the year. Results were incorporated into intern performance reviews and Clinical Competency Committees. A total of 136 sign-outs were audited (averaging 3.1 audits per intern). In the first trimester, 14 interns (31%) had satisfactory audit results. Five interns (11%) had critical deficiencies and received immediate feedback, and the remaining 26 (58%) were assigned future audits due to missing audits or unsatisfactory scores. In the second trimester, 21 interns (68%) had satisfactory results, 1 had critical deficiencies, and 9 (29%) required future audits. Nine of the 10 remaining interns in the final trimester had satisfactory audits. Faculty time was estimated at 10 to 15 minutes per sign-out audited. The UPDATED audit is a milestone-based tool that can be used to assess written sign-out communication skills in internal medicine residency programs. Future work is planned to adapt the tool for use by senior supervisory residents to appraise sign-outs in real time.

  19. Simplified scintigraphic methods for measuring gastrointestinal transit times

    DEFF Research Database (Denmark)

    Graff, J; Brinch, K; Madsen, Jan Lysgård

    2000-01-01

    To investigate whether simple transit measurements based on scintigraphy performed only 0, 2, 4 and 24 h after intake of a radiolabelled meal can be used to predict the mean transit time values for the stomach, the small intestine, and the colon, a study was conducted in 16 healthy volunteers....... After ingestion of a meal containing 111indium-labelled water and 99mtechnetium-labelled omelette, imaging was performed at intervals of 30 min until all radioactivity was located in the colon and henceforth at intervals of 24 h until all radioactivity had cleared from the colon. Gastric, small...... intestinal and colonic mean transit times were calculated for both markers and compared with fractional gastric emptying at 2 h, fractional colonic filling at 4 h, and geometric centre of colonic content at 24 h, respectively. Highly significant correlations were found between gastric mean transit time...

  20. Bisimulation and Open Maps for Timed Transition Systems

    DEFF Research Database (Denmark)

    Nielsen, Mogens

    1999-01-01

    Formal models for real-time systems have been studied intensively over the past decade. Much of the theory of untimed systems have been lifted to real-time settings. One example is the notion of bisimulation applied to timed transition systems, which is studied here within the general categorical...

  1. Daylight Saving Time Transitions and Road Traffic Accidents

    Directory of Open Access Journals (Sweden)

    Tuuli Lahti

    2010-01-01

    Full Text Available Circadian rhythm disruptions may have harmful impacts on health. Circadian rhythm disruptions caused by jet lag compromise the quality and amount of sleep and may lead to a variety of symptoms such as fatigue, headache, and loss of attention and alertness. Even a minor change in time schedule may cause considerable stress for the body. Transitions into and out of daylight saving time alter the social and environmental timing twice a year. According to earlier studies, this change in time-schedule leads to sleep disruption and fragmentation of the circadian rhythm. Since sleep deprivation decreases motivation, attention, and alertness, transitions into and out of daylight saving time may increase the amount of accidents during the following days after the transition. We studied the amount of road traffic accidents one week before and one week after transitions into and out of daylight saving time during years from 1981 to 2006. Our results demonstrated that transitions into and out of daylight saving time did not increase the number of traffic road accidents.

  2. The Transiting System GJ1214: High-Precision Defocused Transit Observations and a Search for Evidence of Transit Timing Variation

    DEFF Research Database (Denmark)

    Harpsøe, Kennet Bomann West; Hardis, S.; Hinse, T. C.

    2012-01-01

    Aims: We present 11 high-precision photometric transit observations of the transiting super-Earth planet GJ1214b. Combining these data with observations from other authors, we investigate the ephemeris for possible signs of transit timing variations (TTVs) using a Bayesian approach. Methods......: The observations were obtained using telescope-defocusing techniques, and achieve a high precision with random errors in the photometry as low as 1mmag per point. To investigate the possibility of TTVs in the light curve, we calculate the overall probability of a TTV signal using Bayesian methods. Results...

  3. No variations in transit times for Qatar-1 b

    Science.gov (United States)

    Maciejewski, G.; Fernández, M.; Aceituno, F. J.; Ohlert, J.; Puchalski, D.; Dimitrov, D.; Seeliger, M.; Kitze, M.; Raetz, St.; Errmann, R.; Gilbert, H.; Pannicke, A.; Schmidt, J.-G.; Neuhäuser, R.

    2015-05-01

    Aims: The transiting hot-Jupiter planet Qatar-1 b exhibits variations in transit times that could be perturbative. A hot Jupiter with a planetary companion on a nearby orbit would constitute an unprecedented planetary configuration, which is important for theories of the formation and evolution of planetary systems. We performed a photometric follow-up campaign to confirm or refute transit timing variations. Methods: We extend the baseline of transit observations by acquiring 18 new transit light curves acquired with 0.6-2.0 m telescopes. These photometric time series, together with data available in the literature, were analyzed in a homogenous way to derive reliable transit parameters and their uncertainties. Results: We show that the dataset of transit times is consistent with a linear ephemeris leaving no hint of any periodic variations with a range of 1 min. We find no compelling evidence of a close-in planetary companion to Qatar-1 b. This finding is in line with a paradigm that hot Jupiters are not components of compact multiplanetary systems. Based on dynamical simulations, we place tighter constraints on the mass of any fictitious nearby planet in the system. Furthermore, new transit light curves allowed us to redetermine system parameters with better precision than reported in previous studies. Our values generally agree with previous determinations. Partly based on (1) data collected with telescopes at the Rozhen National Astronomical Observatory and (2) observations obtained with telescopes of the University Observatory Jena, which is operated by the Astrophysical Institute of the Friedrich-Schiller-University.Tables of light curve data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/577/A109

  4. Computerprogram for the determination of minimal cardiac transit times

    International Nuclear Information System (INIS)

    Bosiljanoff, P.; Herzog, H.; Schmid, A.; Sommer, D.; Vyska, K.; Feinendegen, L.E.

    1982-10-01

    An Anger-Type gamma-camera is used to register the first pass of a radioactive tracer of blood flow through the heart. The acquired data are processed by a suitable computer program yielding time-activity curves for sequential heart segments, which are selected by the region of interest technique. The program prints the minimal cardiac transit times, in terms of total transit times, as well as segmental transit times for the right atrium, right ventricle, lung, left atrium and left ventricle. The measured values are normalized to a rate of 80/min and are compared to normal mean values. The deviation from the normal mean values is characterized by a coefficient F. Moreover, these findings are qualitatively rated. (orig./MG)

  5. Modelling systematics of ground-based transit photometry I. Implications on transit timing variations

    DEFF Research Database (Denmark)

    von Essen, C.; Cellone, S.; Mallonn, M.

    2016-01-01

    introduced a perturbation in the mid-transit times of the hot Jupiter, caused by an Earth-sized planet in a 3:2 mean motion resonance. Analyzing the synthetic light curves produced after certain epochs, we attempt to recover the synthetically added TTV signal by means of usual primary transit fitting...... we attempt to reproduce, by means of physically and empirically motivated relationships, the effects caused by the Earth's atmosphere and the instrumental setup on the synthetic light curves. Therefore, the synthetic data present different photometric quality and transit coverage. In addition, we...

  6. High-Cadence Transit Timing Variation Monitoring of Extrasolar Planets

    Directory of Open Access Journals (Sweden)

    Naef D.

    2011-02-01

    Full Text Available We report ground-based high-cadence transit timing observations of the extrasolar planet WASP-2b. We achieve a typical timing error of 15-30 sec. The data show no significant deviations from the predicted ephemeris.

  7. Mean Transit Time and Mean Residence Time for Linear Diffusion–Convection–Reaction Transport System

    Directory of Open Access Journals (Sweden)

    Jacek Waniewski

    2007-01-01

    Full Text Available Characteristic times for transport processes in biological systems may be evaluated as mean transit times (MTTs (for transit states or mean residence times (MRT (for steady states. It is shown in a general framework of a (linear reaction–diffusion–convection equation that these two times are related. Analytical formulas are also derived to calculate moments of exit time distribution using solutions for a stationary state of the system.

  8. Gastric transit and small intestinal transit time and motility assessed by a magnet tracking system

    Directory of Open Access Journals (Sweden)

    WorsØe Jonas

    2011-12-01

    Full Text Available Abstract Background Tracking an ingested magnet by the Magnet Tracking System MTS-1 (Motilis, Lausanne, Switzerland is an easy and minimally-invasive method to assess gastrointestinal transit. The aim was to test the validity of MTS-1 for assessment of gastric transit time and small intestinal transit time, and to illustrate transit patterns detected by the system. Methods A small magnet was ingested and tracked by an external matrix of 16 magnetic field sensors (4 × 4 giving a position defined by 5 coordinates (position: x, y, z, and angle: θ, ϕ. Eight healthy subjects were each investigated three times: (1 with a small magnet mounted on a capsule endoscope (PillCam; (2 with the magnet alone and the small intestine in the fasting state; and (3 with the magnet alone and the small intestine in the postprandial state. Results Experiment (1 showed good agreement and no systematic differences between MTS-1 and capsule endoscopy when assessing gastric transit (median difference 1 min; range: 0-6 min and small intestinal transit time (median difference 0.5 min; range: 0-52 min. Comparing experiments (1 and (2 there were no systematic differences in gastric transit or small intestinal transit when using the magnet-PillCam unit and the much smaller magnetic pill. In experiments (2 and (3, short bursts of very fast movements lasting less than 5% of the time accounted for more than half the distance covered during the first two hours in the small intestine, irrespective of whether the small intestine was in the fasting or postprandial state. The mean contraction frequency in the small intestine was significantly lower in the fasting state than in the postprandial state (9.90 min-1 vs. 10.53 min-1 (p = 0.03. Conclusion MTS-1 is reliable for determination of gastric transit and small intestinal transit time. It is possible to distinguish between the mean contraction frequency of small intestine in the fasting state and in the postprandial state.

  9. Esophageal transit time in patients with chagasic megaesophagus

    Science.gov (United States)

    Martins, Paula; Ferreira, Cid Sergio; Cunha-Melo, José Renan

    2018-01-01

    Abstract The aim of this study was to determine the esophageal transit time in control individuals and in chagasic patients with or without megaesophagus. A total of 148 patients were allocated in 6 groups according to serological diagnostic of Chagas disease and the degree of esophageal dilatation: A, control healthy individuals (n = 34, 22.9%); B, indeterminate form (n = 23, 15.5%); C, megaesophagus I (n = 37, 25.0%); D, megaesophagus II (n = 19, 12.8%); E, megaesophagus III (n = 21, 14.2%); and F, megaesophagus IV (n = 14, 9.5%). After 8-hour fasting, patients were asked to swallow 75 mL of barium sulfate solution. x-Rays were obtained after 8, 30, 60, and 90 seconds, 5, 10, 30, 60, and 90 minutes, 2, 6, 12, 24 hours, and at every 12 hours until no more contrast was seen in the esophagus. This was the transit time. The transit time varied from 8 seconds to 36 hours (median = 90 seconds). A linear correlation was observed between transit time and megaesophagus grade: 8 seconds in groups A and B, 5 minutes in C, 30 minutes in D, 2 hours in E, and 9:15 hours in F. Dysphagia was not reported by 60 of 114 (52.6%) patients with positive serological tests for Chagas disease (37/91—40.7%—of patients with megaesophagus I–IV grades). The esophageal transit time increased with the grade of megaesophagus. The esophageal transit time has a direct correlation with the grade of megaesophagus; dysphagia complaint correlates with the grade of megaesophagus. However, many patients with megaesophagus do not report dysphagia. PMID:29517674

  10. Simplified scintigraphic methods for measuring gastrointestinal transit times

    DEFF Research Database (Denmark)

    Graff, J; Brinch, K; Madsen, Jan Lysgård

    2000-01-01

    . After ingestion of a meal containing 111indium-labelled water and 99mtechnetium-labelled omelette, imaging was performed at intervals of 30 min until all radioactivity was located in the colon and henceforth at intervals of 24 h until all radioactivity had cleared from the colon. Gastric, small...... intestinal and colonic mean transit times were calculated for both markers and compared with fractional gastric emptying at 2 h, fractional colonic filling at 4 h, and geometric centre of colonic content at 24 h, respectively. Highly significant correlations were found between gastric mean transit time...... and fractional gastric emptying at 2 h (111In: r=0.95, P

  11. A multi-attribute vertical handoff scheme for heterogeneous wireless networks

    Directory of Open Access Journals (Sweden)

    JI Xiaolong

    2014-04-01

    Full Text Available In order to meet the user demand for different services as well as to mitigate the Ping-pong effect caused by vertical handoff for wireless network,a multi-attribute vertical handoff scheme for heterogeneous wireless network is proposed.In the algorithm,a fuzzy logic method is used to make pre-decision.The optimal handoff target network is selected by a cost function of network which uses an Analytic Hierarchy Process to calculate the weights of SNR,delay,cost and user preference in different business scenarios.Simulation is performed in the environment which is overlapped by WiMAX and UMTS networks.Results show that the proposed approach can effectively reduce the number of handoff and power consumption in a condition to satisfy the user needs.

  12. A questionnaire-based survey on nurse perceptions of patient handoffs in japanese hospitals

    DEFF Research Database (Denmark)

    Gu, Xiuzhu; Itoh, Kenji; Andersen, Henning Boje

    2012-01-01

    transfer, responsibility transfer, management goals, environment and handoff system. As an overall trend, Japanese nurses indicated that both information and responsibility for the patient were transferred moderately well within the hospital. They put a higher priority on the goal of patient safety......Patient handoff is a critically important process in healthcare. However, there have been few studies investigated healthcare staff perceptions of its quality and safety. In the present paper, we seek to explore essential characteristics of patient handoff. We discuss critical factors...... and strategies contributing to effective handoffs. A questionnaire survey was conducted in 2011, collecting 1462 valid responses (74% response rate) from nurses in six Japanese hospitals. There were 17 questions, each with reply options on a five-point Likert scale, covering five main aspects: information...

  13. Seamless Vertical Handoff using Invasive Weed Optimization (IWO algorithm for heterogeneous wireless networks

    Directory of Open Access Journals (Sweden)

    T. Velmurugan

    2016-03-01

    Full Text Available Heterogeneous wireless networks are an integration of two different networks. For better performance, connections are to be exchanged among the different networks using seamless Vertical Handoff. The evolutionary algorithm of invasive weed optimization algorithm popularly known as the IWO has been used in this paper, to solve the Vertical Handoff (VHO and Horizontal Handoff (HHO problems. This integer coded algorithm is based on the colonizing behavior of weed plants and has been developed to optimize the system load and reduce the battery power consumption of the Mobile Node (MN. Constraints such as Receiver Signal Strength (RSS, battery lifetime, mobility, load and so on are taken into account. Individual as well as a combination of a number of factors are considered during decision process to make it more effective. This paper brings out the novel method of IWO algorithm for decision making during Vertical Handoff. Therefore the proposed VHO decision making algorithm is compared with the existing SSF and OPTG methods.

  14. An Integrated Multi-layer Approach for Seamless Soft Handoff in Mobile Ad Hoc Networks

    Science.gov (United States)

    2011-01-01

    network to showcase how to leverage the IEEE 802.21 Media Independent Handover ( MIH ) framework [3] in our handoff solution. Moreover, to further...to the seamless handoff problem. The architecture leverages the IEEE 802.21 MIH standard to facilitate handover related decisions on multiple...provided by the MIH function (MIHF), the topology control manager dynamically activates/deactivates the wireless interfaces to ensure the network is

  15. Handoff Rate and Coverage Analysis in Multi-tier Heterogeneous Networks

    OpenAIRE

    Sadr, Sanam; Adve, Raviraj S.

    2015-01-01

    This paper analyzes the impact of user mobility in multi-tier heterogeneous networks. We begin by obtaining the handoff rate for a mobile user in an irregular cellular network with the access point locations modeled as a homogeneous Poisson point process. The received signal-to-interference-ratio (SIR) distribution along with a chosen SIR threshold is then used to obtain the probability of coverage. To capture potential connection failures due to mobility, we assume that a fraction of handoff...

  16. Pixel-by-pixel mean transit time without deconvolution.

    Science.gov (United States)

    Dobbeleir, Andre A; Piepsz, Amy; Ham, Hamphrey R

    2008-04-01

    Mean transit time (MTT) within a kidney is given by the integral of the renal activity on a well-corrected renogram between time zero and time t divided by the integral of the plasma activity between zero and t, providing that t is close to infinity. However, as the data acquisition of a renogram is finite, the MTT calculated using this approach might result in the underestimation of the true MTT. To evaluate the degree of this underestimation we conducted a simulation study. One thousand renograms were created by convoluting various plasma curves obtained from patients with different renal clearance levels with simulated retentions curves having different shapes and mean transit times. For a 20 min renogram, the calculated MTT started to underestimate the MTT when the MTT was higher than 6 min. The longer the MTT, the greater was the underestimation. Up to a MTT value of 6 min, the error on the MTT estimation is negligible. As normal cortical transit is less than 2 min, this approach is used for patients to calculate pixel-to-pixel cortical mean transit time and to create a MTT parametric image without deconvolution.

  17. Characterizing the structure and content of nurse handoffs: A Sequential Conversational Analysis approach.

    Science.gov (United States)

    Abraham, Joanna; Kannampallil, Thomas; Brenner, Corinne; Lopez, Karen D; Almoosa, Khalid F; Patel, Bela; Patel, Vimla L

    2016-02-01

    Effective communication during nurse handoffs is instrumental in ensuring safe and quality patient care. Much of the prior research on nurse handoffs has utilized retrospective methods such as interviews, surveys and questionnaires. While extremely useful, an in-depth understanding of the structure and content of conversations, and the inherent relationships within the content is paramount to designing effective nurse handoff interventions. In this paper, we present a methodological framework-Sequential Conversational Analysis (SCA)-a mixed-method approach that integrates qualitative conversational analysis with quantitative sequential pattern analysis. We describe the SCA approach and provide a detailed example as a proof of concept of its use for the analysis of nurse handoff communication in a medical intensive care unit. This novel approach allows us to characterize the conversational structure, clinical content, disruptions in the conversation, and the inherently phasic nature of nurse handoff communication. The characterization of communication patterns highlights the relationships underlying the verbal content of nurse handoffs with specific emphasis on: the interactive nature of conversation, relevance of role-based (incoming, outgoing) communication requirements, clinical content focus on critical patient-related events, and discussion of pending patient management tasks. We also discuss the applicability of the SCA approach as a method for providing in-depth understanding of the dynamics of communication in other settings and domains. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Constipation and Colonic Transit Times in Children With Morbid Obesity

    NARCIS (Netherlands)

    van der Baan-Slootweg, Olga H.; Liem, Olivia; Bekkali, Noor; van Aalderen, Wim M. C.; Rijcken, Tammo H. Pels; Di Lorenzo, Carlo; Benninga, Marc A.

    2011-01-01

    Objectives: The aim of the study was to determine the frequency of functional constipation according to the Rome III criteria in children with morbid obesity and to evaluate by measuring colonic transit times (CTTs) whether decreased colonic motility is present in these children. Patients and

  19. Caregivers' Playfulness and Infants' Emotional Stress during Transitional Time

    Science.gov (United States)

    Jung, Jeesun

    2011-01-01

    The purpose of this study is to explore the playfulness of the teachers of infants and its relations to infants' emotional distress during the transitional time at a child care centre. The study used a qualitative case study. Two infant caregivers in a university-based child care centre participated in this study. For the three-month research…

  20. Real-time rescheduling and disruption management for public transit

    NARCIS (Netherlands)

    Lai, D.S.W.; Leung, Janny M.Y.

    2017-01-01

    This research is motivated by the operations of a public transit company in Hong Kong. We investigate how real-time information can be utilized in combination with historical data to improve routing and scheduling decisions practically. A dynamic integrated vehicle and crew scheduling problem is

  1. Time delay between cardiac and brain activity during sleep transitions

    NARCIS (Netherlands)

    Long, X.; Arends, J.B.A.M.; Aarts, R.M.; Haakma, R.; Fonseca, P.; Rolink, J.

    2015-01-01

    Human sleep consists of wake, rapid-eye-movement (REM) sleep, and non-REM (NREM) sleep that includes light and deep sleep stages. This work investigated the time delay between changes of cardiac and brain activity for sleep transitions. Here, the brain activity was quantified by

  2. Room acoustic transition time based on reflection overlap

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Brunskog, Jonas; Jacobsen, Finn

    2010-01-01

    A transition time is defined based on the temporal overlap of reflected pulses in room impulse responses. Assuming specular reflections only, the temporal distance between adjacent reflections, which is proportional to the volume of a room, is compared with the characteristic width of a pulse at ...... in a room with nonuniform absorption and furniture than in a room that satisfies the underlying assumptions....

  3. Room acoustic transition time based on reflection overlap

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Brunskog, Jonas; Jacobsen, Finn

    2013-01-01

    A transition time is defined based on the temporal overlap of reflected pulses in room impulse responses. Assuming specular reflections only, the temporal distance between adjacent reflections, which is proportional to the volume of a room, is compared with the characteristic width of a pulse at ...... in a room with nonuniform absorption and furniture than in a room that satisfies the underlying assumptions....

  4. Oro-cecal transit time : influence of a subsequent meal

    NARCIS (Netherlands)

    Priebe, MG; Wachters-Hagedoorn, RE; Stellaard, F; Heiner, AM; Elzinga, H; Vonk, RJ

    Background Small intestinal and oro-cecal transit time (OCTT) is determined for clinical diagnostics and research purposes. Experimental protocols used vary with respect to the inclusion of a subsequent meal during the test period. This study was conducted to elucidate whether the ingestion of a

  5. Part-time Labor, Work Rules, and Transit Costs

    Science.gov (United States)

    1981-01-01

    This report examines two major issues: (1)the impact of labor union work rules : on bus transit operating costs and (2)the magnitude of cost savings that can be : expected from the use of part-time drivers. These issues are examined within : the cont...

  6. Assessment of colonic transit time using MRI: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Buhmann, Sonja; Reiser, Maximilian F.; Lienemann, Andreas [Ludwig-Maximilians-University, Department of Clinical Radiology, Campus Grosshadern, Munich (Germany); Kirchhoff, Chlodwig; Ladurner, Roland; Mussack, Thomas [Ludwig-Maximilians-University, Department of Surgery and Traumatology, Campus Innenstadt, Munich (Germany)

    2007-03-15

    The aim of this pilot study was to evaluate a new, non-invasive examination method using MRI for the quantification of the colonic transit time after oral administration of gadolinium-saline solution filled capsules. Healthy volunteers without previous or acute symptoms of gastrointestinal disorders were enrolled. After a 3-day diet for the standardization of gastrocolonic content the volunteers swallowed five Gd-DTPA/saline 0.9%-filledcapsules. Seven different concentrations of Gd-DTPA/saline 0.9% solution between 1:0 and 0:1 were tested in a dilution series. Following ingestion of capsules, coronal Flash T1 and True Fisp sequences using a 1.5 Tesla system were obtained at 0 h, 3 h, 6 h, 12 h, 24 h, 36 h and 60 h. Sequences were analyzed by two independent experts for locating the capsules. Overall colonic transit time was separately analyzed for both genders. Fifteen healthy volunteers (7 females, 8 males; mean age 34{+-}13 years) were enrolled. The phantom study provided the best contrast in both the T1-and T2-weighted sequences defining a ratio of 1:10 for Gd-DTPA/saline 0.9% solution. The mean transit time accounted for 41{+-}9 h in women and for 31{+-}10 h in men. MRI is an adequate method for the assessment of colonic transit time offering the advantages of no exposure to radiation, short examination time, possible dynamic evaluation of the transit and the practicability in terms of a future adoption to clinical routine. (orig.)

  7. Assessment of colonic transit time using MRI: a feasibility study

    International Nuclear Information System (INIS)

    Buhmann, Sonja; Reiser, Maximilian F.; Lienemann, Andreas; Kirchhoff, Chlodwig; Ladurner, Roland; Mussack, Thomas

    2007-01-01

    The aim of this pilot study was to evaluate a new, non-invasive examination method using MRI for the quantification of the colonic transit time after oral administration of gadolinium-saline solution filled capsules. Healthy volunteers without previous or acute symptoms of gastrointestinal disorders were enrolled. After a 3-day diet for the standardization of gastrocolonic content the volunteers swallowed five Gd-DTPA/saline 0.9%-filledcapsules. Seven different concentrations of Gd-DTPA/saline 0.9% solution between 1:0 and 0:1 were tested in a dilution series. Following ingestion of capsules, coronal Flash T1 and True Fisp sequences using a 1.5 Tesla system were obtained at 0 h, 3 h, 6 h, 12 h, 24 h, 36 h and 60 h. Sequences were analyzed by two independent experts for locating the capsules. Overall colonic transit time was separately analyzed for both genders. Fifteen healthy volunteers (7 females, 8 males; mean age 34±13 years) were enrolled. The phantom study provided the best contrast in both the T1-and T2-weighted sequences defining a ratio of 1:10 for Gd-DTPA/saline 0.9% solution. The mean transit time accounted for 41±9 h in women and for 31±10 h in men. MRI is an adequate method for the assessment of colonic transit time offering the advantages of no exposure to radiation, short examination time, possible dynamic evaluation of the transit and the practicability in terms of a future adoption to clinical routine. (orig.)

  8. Transition in adolescents across time, disease and gender

    DEFF Research Database (Denmark)

    Aagaard, Hanne; Ludvigsen, Mette Spliid; Svanholm, Jette Rolf

    interview with the adolescent at outpatient clinics at Aarhus University Hospital. Follow-up is planned at 15 and 18 years of age. A comparative approach is employed to show central characteristics across time, disease and gender. Results: Results from analysis inspired by Ricoeur's phenomenological......Background: Despite a growing number of studies on transition to adulthood in adolescents, literature is scarce on qualitative, longitudinal studies of transitions in adolescents with severe chronic diseases. The aim is to study transition in adolescents with cystic fibrosis, congenital heart...... diseases and chronic kidney diseases. We specifically focus on the adolescents’ experiences, 'what is important to them', 'what characterises their interaction with health care staff' and 'the communication between the adolescents and health care staff as perceived by the adolescents'. Methods...

  9. Time delay between cardiac and brain activity during sleep transitions

    Science.gov (United States)

    Long, Xi; Arends, Johan B.; Aarts, Ronald M.; Haakma, Reinder; Fonseca, Pedro; Rolink, Jérôme

    2015-04-01

    Human sleep consists of wake, rapid-eye-movement (REM) sleep, and non-REM (NREM) sleep that includes light and deep sleep stages. This work investigated the time delay between changes of cardiac and brain activity for sleep transitions. Here, the brain activity was quantified by electroencephalographic (EEG) mean frequency and the cardiac parameters included heart rate, standard deviation of heartbeat intervals, and their low- and high-frequency spectral powers. Using a cross-correlation analysis, we found that the cardiac variations during wake-sleep and NREM sleep transitions preceded the EEG changes by 1-3 min but this was not the case for REM sleep transitions. These important findings can be further used to predict the onset and ending of some sleep stages in an early manner.

  10. Dual-Priced Modal Transition Systems with Time Durations

    DEFF Research Database (Denmark)

    Beneš, Nikola; Kretínsky, Jan; Larsen, Kim Guldstrand

    2012-01-01

    Modal transition systems are a well-established specification formalism for a high-level modelling of component-based software systems. We present a novel extension of the formalism called modal transition systems with durations where time durations are modelled as controllable or uncontrollable...... intervals. We further equip the model with two kinds of quantitative aspects: each action has its own running cost per time unit, and actions may require several hardware components of different costs. We ask the question, given a fixed budget for the hardware components, what is the implementation...... with the cheapest long-run average reward. We give an algorithm for computing such optimal implementations via a reduction to a new extension of mean payoff games with time durations and analyse the complexity of the algorithm....

  11. Integrated response and transit time distributions of watersheds by combining hydrograph separation and long-term transit time modeling

    Directory of Open Access Journals (Sweden)

    M. C. Roa-García

    2010-08-01

    Full Text Available We present a new modeling approach analyzing and predicting the Transit Time Distribution (TTD and the Response Time Distribution (RTD from hourly to annual time scales as two distinct hydrological processes. The model integrates Isotope Hydrograph Separation (IHS and the Instantaneous Unit Hydrograph (IUH approach as a tool to provide a more realistic description of transit and response time of water in catchments. Individual event simulations and parameterizations were combined with long-term baseflow simulation and parameterizations; this provides a comprehensive picture of the catchment response for a long time span for the hydraulic and isotopic processes. The proposed method was tested in three Andean headwater catchments to compare the effects of land use on hydrological response and solute transport. Results show that the characteristics of events and antecedent conditions have a significant influence on TTD and RTD, but in general the RTD of the grassland dominated catchment is concentrated in the shorter time spans and has a higher cumulative TTD, while the forest dominated catchment has a relatively higher response distribution and lower cumulative TTD. The catchment where wetlands concentrate shows a flashier response, but wetlands also appear to prolong transit time.

  12. Taste and Temperature in Swallowing Transit Time after Stroke

    Directory of Open Access Journals (Sweden)

    Paula C. Cola

    2012-09-01

    Full Text Available Background: Oropharyngeal dysphagia is common in individuals after stroke. Taste and temperature are used in dysphagia rehabilitation. The influence of stimuli, such as taste and temperature, on swallowing biomechanics has been investigated in both healthy individuals and in individuals with neurological disease. However, some questions still remain unanswered, such as how the sequence of offered stimuli influences the pharyngeal response. The goal of the present study was to determine the influence of the sequence of stimuli, sour taste and cold temperature, on pharyngeal transit time during deglutition in individuals after stroke. Methods: The study included 60 individuals with unilateral ischemic stroke, 29 males and 31 females, aged 41–88 years (mean age: 66.2 years examined 0–50 days after ictus (median: 6 days, with mild to moderate oropharyngeal dysphagia. Exclusion criteria were hemorrhagic stroke patients, patients with decreased level of consciousness, and clinically unstable patients, as confirmed by medical evaluation. The individuals were divided into two groups of 30 individuals each. Group 1 received a nonrandomized sequence of stimuli (i.e. natural, cold, sour, and sour-cold and group 2 received a randomized sequence of stimuli. A videofluoroscopic swallowing study was performed to analyze the pharyngeal transit time. Four different stimuli (natural, cold, sour, and sour-cold were offered. The images were digitalized and specific software was used to measure the pharyngeal transit time. Since the values did not present regular distribution and uniform variances, nonparametric tests were performed. Results: Individuals in group 1 presented a significantly shorter pharyngeal transit time with the sour-cold stimulus than with the other stimuli. Individuals in group 2 did not show a significant difference in pharyngeal transit time between stimuli. Conclusions: The results showed that the sequence of offered stimuli influences

  13. Transition of Care Practices from Emergency Department to Inpatient: Survey Data and Development of Algorithm

    Directory of Open Access Journals (Sweden)

    Sangil Lee

    2017-01-01

    Full Text Available We aimed to assess the current scope of handoff education and practice among resident physicians in academic centers and to propose a standardized handoff algorithm for the transition of care from the emergency department (ED to an inpatient setting. This was a cross-sectional survey targeted at the program directors, associate or assistant program directors, and faculty members of emergency medicine (EM residency programs in the United States (U.S.. The web-based survey was distributed to potential subjects through a listserv. A panel of experts used a modified Delphi approach to develop a standardized algorithm for ED to inpatient handoff. 121 of 172 programs responded to the survey for an overall response rate of 70.3%. Our survey showed that most EM programs in the U.S. have some form of handoff training, and the majority of them occur either during orientation or in the clinical setting. The handoff structure from ED to inpatient is not well standardized, and in those places with a formalized handoff system, over 70% of residents do not uniformly follow it. Approximately half of responding programs felt that their current handoff system was safe and effective. About half of the programs did not formally assess the handoff proficiency of trainees. Handoffs most commonly take place over the phone, though respondents disagree about the ideal place for a handoff to occur, with nearly equivalent responses between programs favoring the bedside over the phone or faceto-face on a computer. Approximately two-thirds of responding programs reported that their residents were competent in performing ED to inpatient handoffs. Based on this survey and on the review of the literature, we developed a five-step algorithm for the transition of care from the ED to the inpatient setting. Our results identified the current trends of education and practice in transitions of care, from the ED to the inpatient setting in U.S. academic medical centers. An algorithm

  14. Watching excitons move: the time-dependent transition density matrix

    Science.gov (United States)

    Ullrich, Carsten

    2012-02-01

    Time-dependent density-functional theory allows one to calculate excitation energies and the associated transition densities in principle exactly. The transition density matrix (TDM) provides additional information on electron-hole localization and coherence of specific excitations of the many-body system. We have extended the TDM concept into the real-time domain in order to visualize the excited-state dynamics in conjugated molecules. The time-dependent TDM is defined as an implicit density functional, and can be approximately obtained from the time-dependent Kohn-Sham orbitals. The quality of this approximation is assessed in simple model systems. A computational scheme for real molecular systems is presented: the time-dependent Kohn-Sham equations are solved with the OCTOPUS code and the time-dependent Kohn-Sham TDM is calculated using a spatial partitioning scheme. The method is applied to show in real time how locally created electron-hole pairs spread out over neighboring conjugated molecular chains. The coupling mechanism, electron-hole coherence, and the possibility of charge separation are discussed.

  15. Lifetime measurements in transitional nuclei by fast electronic scintillation timing

    Science.gov (United States)

    Caprio, M. A.; Zamfir, N. V.; Casten, R. F.; Amro, H.; Barton, C. J.; Beausang, C. W.; Cooper, J. R.; Gürdal, G.; Hecht, A. A.; Hutter, C.; Krücken, R.; McCutchan, E. A.; Meyer, D. A.; Novak, J. R.; Pietralla, N.; Ressler, J. J.; Berant, Z.; Brenner, D. S.; Gill, R. L.; Regan, P. H.

    2002-10-01

    A new generation of experiments studying nuclei in spherical-deformed transition regions has been motivated by the introduction of innovative theoretical approaches to the treatment of these nuclei. The important structural signatures in the transition regions, beyond the basic yrast level properties, involve γ-ray transitions between low-spin, non-yrast levels, and so information on γ-ray branching ratios and absolute matrix elements (or level lifetimes) for these transitions is crucial. A fast electronic scintillation timing (FEST) system [H. Mach, R. L. Gill, and M. Moszyński, Nucl. Instrum. Methods A 280, 49 (1989)], making use of BaF2 and plastic scintillation detectors, has been implemented at the Yale Moving Tape Collector for the measurement of lifetimes of states populated in β^ decay. Experiments in the A100 (Pd, Ru) and A150 (Dy, Yb) regions have been carried out, and a few examples will be presented. Supported by the US DOE under grants and contracts DE-FG02-91ER-40609, DE-FG02-88ER-40417, and DE-AC02-98CH10886 and by the German DFG under grant Pi 393/1.

  16. Transit time spreads in biased paracentric hemispherical deflection analyzers

    International Nuclear Information System (INIS)

    Sise, Omer; Zouros, Theo J.M.

    2016-01-01

    The biased paracentric hemispherical deflection analyzers (HDAs) are an alternative to conventional (centric) HDAs maintaining greater dispersion, lower angular aberrations, and hence better energy resolution without the use of any additional fringing field correctors. In the present work, the transit time spread of the biased paracentric HDA is computed over a wide range of analyzer parameters. The combination of high energy resolution with good time resolution and simplicity of design makes the biased paracentric analyzers very promising for both coincidence and singles spectroscopy applications.

  17. Transit time spreads in biased paracentric hemispherical deflection analyzers

    Energy Technology Data Exchange (ETDEWEB)

    Sise, Omer, E-mail: omersise@sdu.edu.tr [Dept. of Science Education, Faculty of Education, Suleyman Demirel Univ., 32260 Isparta (Turkey); Zouros, Theo J.M. [Dept. of Physics, Univ. of Crete, P.O. Box 2208, GR 71003 Heraklion (Greece); Tandem Lab, INPP, NCSR Demokritos, P.O. Box 60228, GR 15310 Ag. Paraskevi (Greece)

    2016-02-15

    The biased paracentric hemispherical deflection analyzers (HDAs) are an alternative to conventional (centric) HDAs maintaining greater dispersion, lower angular aberrations, and hence better energy resolution without the use of any additional fringing field correctors. In the present work, the transit time spread of the biased paracentric HDA is computed over a wide range of analyzer parameters. The combination of high energy resolution with good time resolution and simplicity of design makes the biased paracentric analyzers very promising for both coincidence and singles spectroscopy applications.

  18. Transit time spreads in biased paracentric hemispherical deflection analyzers

    Science.gov (United States)

    Sise, Omer; Zouros, Theo J. M.

    2016-02-01

    The biased paracentric hemispherical deflection analyzers (HDAs) are an alternative to conventional (centric) HDAs maintaining greater dispersion, lower angular aberrations, and hence better energy resolution without the use of any additional fringing field correctors. In the present work, the transit time spread of the biased paracentric HDA is computed over a wide range of analyzer parameters. The combination of high energy resolution with good time resolution and simplicity of design makes the biased paracentric analyzers very promising for both coincidence and singles spectroscopy applications.

  19. Development, implementation and evaluation of a patient handoff tool to improve safety in orthopaedic surgery.

    Science.gov (United States)

    Gagnier, Joel J; Derosier, Joseph M; Maratt, Joseph D; Hake, Mark E; Bagian, James P

    2016-06-01

    To develop, implement and test the effect of a handoff tool for orthopaedic trauma residents that reduces adverse events associated with the omission of critical information and the transfer of erroneous information. Components of this project included a literature review, resident surveys and observations, checklist development and refinement, implementation and evaluation of impact on adverse events through a chart review of a prospective cohort compared with a historical control group. Large teaching hospital. Findings of a literature review were presented to orthopaedic residents, epidemiologists, orthopaedic surgeons and patient safety experts in face-to-face meetings, during which we developed and refined the contents of a resident handoff tool. The tool was tested in an orthopaedic trauma service and its impact on adverse events was evaluated through a chart review. The handoff tool was developed and refined during the face-to-face meetings and a pilot implementation. Adverse event data were collected on 127 patients (n = 67 baseline period; n = 60 test period). A handoff tool for use by orthopaedic residents. Adverse events in patients handed off by orthopaedic trauma residents. After controlling for age, gender and comorbidities, testing resulted in fewer events per person (25-27% reduction; P < 0.10). Preliminary evidence suggests that our resident handoff tool may contribute to a decrease in adverse events in orthopaedic patients. © The Author 2016. Published by Oxford University Press in association with the International Society for Quality in Health Care; all rights reserved.

  20. Optimizing the search for transiting planets in long time series

    Science.gov (United States)

    Ofir, Aviv

    2014-01-01

    Context. Transit surveys, both ground- and space-based, have already accumulated a large number of light curves that span several years. Aims: The search for transiting planets in these long time series is computationally intensive. We wish to optimize the search for both detection and computational efficiencies. Methods: We assume that the searched systems can be described well by Keplerian orbits. We then propagate the effects of different system parameters to the detection parameters. Results: We show that the frequency information content of the light curve is primarily determined by the duty cycle of the transit signal, and thus the optimal frequency sampling is found to be cubic and not linear. Further optimization is achieved by considering duty-cycle dependent binning of the phased light curve. By using the (standard) BLS, one is either fairly insensitive to long-period planets or less sensitive to short-period planets and computationally slower by a significant factor of ~330 (for a 3 yr long dataset). We also show how the physical system parameters, such as the host star's size and mass, directly affect transit detection. This understanding can then be used to optimize the search for every star individually. Conclusions: By considering Keplerian dynamics explicitly rather than implicitly one can optimally search the BLS parameter space. The presented Optimal BLS enhances the detectability of both very short and very long period planets, while allowing such searches to be done with much reduced resources and time. The Matlab/Octave source code for Optimal BLS is made available. The MATLAB code is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/561/A138

  1. TRANSIT TIMING VARIATIONS FOR INCLINED AND RETROGRADE EXOPLANETARY SYSTEMS

    International Nuclear Information System (INIS)

    Payne, Matthew J.; Ford, Eric B.; Veras, Dimitri

    2010-01-01

    We perform numerical calculations of the expected transit timing variations (TTVs) induced on a hot-Jupiter by an Earth-mass perturber. Motivated by the recent discoveries of retrograde transiting planets, we concentrate on an investigation of the effect of varying relative planetary inclinations, up to and including completely retrograde systems. We find that planets in low-order (e.g., 2:1) mean-motion resonances (MMRs) retain approximately constant TTV amplitudes for 0 deg. 170 deg. Systems in higher order MMRs (e.g., 5:1) increase in TTV amplitude as inclinations increase toward 45 deg., becoming approximately constant for 45 deg. 135 deg. Planets away from resonance slowly decrease in TTV amplitude as inclinations increase from 0 deg. to 180 deg., whereas planets adjacent to resonances can exhibit a huge range of variability in TTV amplitude as a function of both eccentricity and inclination. For highly retrograde systems (135 deg. < i ≤ 180 deg.), TTV signals will be undetectable across almost the entirety of parameter space, with the exceptions occurring when the perturber has high eccentricity or is very close to an MMR. This high inclination decrease in TTV amplitude (on and away from resonance) is important for the analysis of the known retrograde and multi-planet transiting systems, as inclination effects need to be considered if TTVs are to be used to exclude the presence of any putative planetary companions: absence of evidence is not evidence of absence.

  2. The meaning of transit times in NDT of reinforced concrete

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2007-10-01

    Transit times of longitudinal pulses that travel near reinforcing steel bars are usually smaller than in plain concrete. Chung first, and then Bungey, demonstrated the importance of including bar diameters in the correction factors when pulses propagating parallel and near to the bars can not be avoided. Besides the influence of geometric dispersion and mode conversion on pulse propagation, there is an effect due to a specific pattern of radial variation of longitudinal wave velocities from the surface of the embedded steel bar. Wall effects produce a region (a sheath) of concrete surrounding the steel bar, with smaller longitudinal pulse velocities in comparison with the velocity farther away from the bar. Then the acoustics energy travels trapped in a kind of composite leaky waveguide with a velocity less than the compression (P) wave velocity in steel and in concrete but greater than the extensional wave velocity in steel. A mathematical model of the propagation of a longitudinal wave-packet is constructed, taking into account both attenuation and dispersion effects. An asymptotic analysis of pulse propagation and the introduction of a threshold of detection in the receiving transducer, allows the derivation of an approximate analytical formula for transit times. Then the meaning of transit times in NDT of concrete is discussed. The above mentioned formula is used to study the effects of the reinforcing bar radius, the propagation parameters in plain concrete and in the sheath surrounding the steel bar, the path length between the transmitting and the receiving transducers, and the energy and the spectral composition of the pulse injected by the emitter in the tested body. Chung s empirical correlation between the measured pulse velocity and bar radius is reviewed and a new correlation is proposed

  3. Analysis and study of a handoff scheme with multiple priority strategies

    Institute of Scientific and Technical Information of China (English)

    李波; 吴成柯; 椋本介士; 福田明

    2000-01-01

    A handoff scheme with the combination of channel reservation and preemptive priority in integrated voice/data cellular mobile systems is proposed. In the scheme, calls are divided into three different classes: handoff voice calls, originating voice calls, and data calls. An access strategy with the combination of channel reservation and preemptive priority is provided to a handoff voice call. Furthermore, in order to improve the system capacity for the total voice traffic, preemptive priority is also given to partial originating voice calls. The system is modeled by a two-dimensional Markov chain. Both the iteration method and the approximate method are used to calculate and analyze some of the most important performance measures of the system. It is shown that our scheme can provide better quality of services for mobile subscribers.

  4. An 802.11k Compliant Framework for Cooperative Handoff in Wireless Networks

    Directory of Open Access Journals (Sweden)

    Korakis Thanasis

    2009-01-01

    Full Text Available Abstract In IEEE 802.11-based wireless networks, the stations (STAs are associated with the available access points (APs and communicate through them. In traditional handoff schemes, the STAs get information about the active APs in their neighborhood by scanning the available channels and listening to transmitted beacons. This paper proposes an 802.11k compliant framework for cooperative handoff where the STAs are informed about the active APs by exchanging information with neighboring STAs. Besides, the APs share useful information that can be used by the STAs in a handoff process. In this way, we minimize the delay of the scanning procedure. We evaluate the performance of our mechanisms through OPNET simulations. We demonstrate that our scheme reduces the scanning delay up to 92%. Consequently, our system is more capable in meeting the needs of QoS-sensitive applications.

  5. Target Channel Visiting Order Design Using Particle Swarm Optimization for Spectrum Handoff in Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    Shilian Zheng

    2014-08-01

    Full Text Available In a dynamic spectrum access network, when a primary user (licensed user reappears on the current channel, cognitive radios (CRs need to vacate the channel and reestablish a communications link on some other channel to avoid interference to primary users, resulting in spectrum handoff. This paper studies the problem of designing target channel visiting order for spectrum handoff to minimize expected spectrum handoff delay. A particle swarm optimization (PSO based algorithm is proposed to solve the problem. Simulation results show that the proposed algorithm performs far better than random target channel visiting scheme. The solutions obtained by PSO are very close to the optimal solution which further validates the effectiveness of the proposed method.

  6. Time-dependent reflection at the localization transition

    Science.gov (United States)

    Skipetrov, Sergey E.; Sinha, Aritra

    2018-03-01

    A short quasimonochromatic wave packet incident on a semi-infinite disordered medium gives rise to a reflected wave. The intensity of the latter decays as a power law, 1 /tα , in the long-time limit. Using the one-dimensional Aubry-André model, we show that in the vicinity of the critical point of Anderson localization transition, the decay slows down, and the power-law exponent α becomes smaller than both α =2 found in the Anderson localization regime and α =3 /2 expected for a one-dimensional random walk of classical particles.

  7. Analysis of transit time spread on FBK silicon photomultipliers

    International Nuclear Information System (INIS)

    Acerbi, F.; Gola, A.; Ferri, A.; Zorzi, N.; Paternoster, G.; Piemonte, C.

    2015-01-01

    In this paper we studied one of the aspects potentially limiting the single-photon time-resolution (SPTR) of the silicon photomultiplier (SiPM): the transit time spread (TTS). We illuminated the SiPM in different positions with a fast-pulsed laser collimated to a circular spot of 0.2 mm-diameter and acquired bi-dimensional maps of the avalanche-signal arrival time of RGB and RGB-HD SiPMs, produced at FBK. We studied the effect of both the number of bonding wires connecting the device to the package and the layout of the top-metal connection (on the device). We found that the TTS does not simply depend on the trace length between the cell and the bonding pad and it could vary in the range between tens of picoseconds (with 3 bonding connections) to more than one hundred of picoseconds (with one connection)

  8. Per-energy capacity and handoff strategies in macro-femto cells environment

    KAUST Repository

    Leon, Jaime; Bader, Faouzi; Alouini, Mohamed-Slim

    2012-01-01

    The effect of smaller cells being placed in a heterogenous network can improve the way energy is spent in a system. Handoff strategies, bandwidth allocation and path loss calculations in different scenarios show how this is possible as the size of the cell is decreased. As a result, users can experience the same or better capacities while maximising the capacity per unit energy spent. The per-energy capacity metric is introduced as a suitable handoff strategy that considers the energy spent as an important criterion. © 2012 IEEE.

  9. Per-energy capacity and handoff strategies in macro-femto cells environment

    KAUST Repository

    Leon, Jaime

    2012-04-01

    The effect of smaller cells being placed in a heterogenous network can improve the way energy is spent in a system. Handoff strategies, bandwidth allocation and path loss calculations in different scenarios show how this is possible as the size of the cell is decreased. As a result, users can experience the same or better capacities while maximising the capacity per unit energy spent. The per-energy capacity metric is introduced as a suitable handoff strategy that considers the energy spent as an important criterion. © 2012 IEEE.

  10. The length and time scales of water's glass transitions

    Science.gov (United States)

    Limmer, David T.

    2014-06-01

    Using a general model for the equilibrium dynamics of supercooled liquids, I compute from molecular properties the emergent length and time scales that govern the nonequilibrium relaxation behavior of amorphous ice prepared by rapid cooling. Upon cooling, the liquid water falls out of equilibrium whereby the temperature dependence of its relaxation time is predicted to change from super-Arrhenius to Arrhenius. A consequence of this crossover is that the location of the apparent glass transition temperature depends logarithmically on cooling rate. Accompanying vitrification is the emergence of a dynamical length-scale, the size of which depends on the cooling rate and varies between angstroms and tens of nanometers. While this protocol dependence clarifies a number of previous experimental observations for amorphous ice, the arguments are general and can be extended to other glass forming liquids.

  11. The length and time scales of water's glass transitions.

    Science.gov (United States)

    Limmer, David T

    2014-06-07

    Using a general model for the equilibrium dynamics of supercooled liquids, I compute from molecular properties the emergent length and time scales that govern the nonequilibrium relaxation behavior of amorphous ice prepared by rapid cooling. Upon cooling, the liquid water falls out of equilibrium whereby the temperature dependence of its relaxation time is predicted to change from super-Arrhenius to Arrhenius. A consequence of this crossover is that the location of the apparent glass transition temperature depends logarithmically on cooling rate. Accompanying vitrification is the emergence of a dynamical length-scale, the size of which depends on the cooling rate and varies between angstroms and tens of nanometers. While this protocol dependence clarifies a number of previous experimental observations for amorphous ice, the arguments are general and can be extended to other glass forming liquids.

  12. Recurrence and symmetry of time series: Application to transition detection

    International Nuclear Information System (INIS)

    Girault, Jean-Marc

    2015-01-01

    Highlights: •A new theoretical framework based on the symmetry concept is proposed. •Four types of symmetry present in any time series were analyzed. •New descriptors make possible the analysis of regime changes in logistic systems. •Chaos–chaos, chaos–periodic, symmetry-breaking, symmetry-increasing bifurcations can be detected. -- Abstract: The study of transitions in low dimensional, nonlinear dynamical systems is a complex problem for which there is not yet a simple, global numerical method able to detect chaos–chaos, chaos–periodic bifurcations and symmetry-breaking, symmetry-increasing bifurcations. We present here for the first time a general framework focusing on the symmetry concept of time series that at the same time reveals new kinds of recurrence. We propose several numerical tools based on the symmetry concept allowing both the qualification and quantification of different kinds of possible symmetry. By using several examples based on periodic symmetrical time series and on logistic and cubic maps, we show that it is possible with simple numerical tools to detect a large number of bifurcations of chaos–chaos, chaos–periodic, broken symmetry and increased symmetry types

  13. Colonic transit time in patient with slow-transit constipation: Comparison of radiopaque markers and barium suspension method

    Energy Technology Data Exchange (ETDEWEB)

    Xu Huimin [Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, No. 8 Gongtina Lu, Chaoyang District, Beijing 100020 (China); Department of General Surgery, Weifang People' s Hospital, ShanDong Province 261041 (China); Han Jiagang [Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, No. 8 Gongtina Lu, Chaoyang District, Beijing 100020 (China); Na Ying [Department of Medical Imaging, Weifang People' s Hospital, ShanDong Province 261041 (China); Zhao Bo; Ma Huachong [Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, No. 8 Gongtina Lu, Chaoyang District, Beijing 100020 (China); Wang Zhenjun, E-mail: wang3zj@sohu.com [Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, No. 8 Gongtina Lu, Chaoyang District, Beijing 100020 (China)

    2011-08-15

    Background: Colonic transit study provides valuable information before surgical treatment is considered for patient with constipation. The radiopaque markers method is the most common way for evaluating colon transit time. The aim of this study is to compare the barium suspension with the radiopaque makers to assess the colonic mobility in patient with constipation. Methods: Colonic transit time was measured in 11 female patients with slow-transit constipation using both radiopaque markers and barium suspension method. In radiopaque markers method, the patient ingested 20 markers on the first day, and an abdominal radiograph was performed every 24 h until 80% markers were excreted. In barium suspension method, the patient swallowed up to 50 ml of 200% (w/v) barium meal. The abdominal radiographs were taken at the same time point as the former. Results: The total or segmental colonic transit time were obviously prolonged in all patients. Segmental transits time spent in the right colon, left colon and rectosigmoid for radiopaque markers and barium suspension method was, respectively, 30 {+-} 6 h and 34 {+-} 7 h; 38 {+-} 9 h and 32 {+-} 6 h; 40 {+-} 8 h and 38 {+-} 10 h. In the radiopaque markers method, total colonic transit time was 108 {+-} 14 h and it was 103 {+-} 13 h in the barium suspension method (P > 0.05). Conclusion: The barium suspension and radiopaque markers gave the similar results for colonic transit time. The barium suspension was a simple and cheap method for evaluating the colonic mobility.

  14. Colonic transit time in patient with slow-transit constipation: Comparison of radiopaque markers and barium suspension method

    International Nuclear Information System (INIS)

    Xu Huimin; Han Jiagang; Na Ying; Zhao Bo; Ma Huachong; Wang Zhenjun

    2011-01-01

    Background: Colonic transit study provides valuable information before surgical treatment is considered for patient with constipation. The radiopaque markers method is the most common way for evaluating colon transit time. The aim of this study is to compare the barium suspension with the radiopaque makers to assess the colonic mobility in patient with constipation. Methods: Colonic transit time was measured in 11 female patients with slow-transit constipation using both radiopaque markers and barium suspension method. In radiopaque markers method, the patient ingested 20 markers on the first day, and an abdominal radiograph was performed every 24 h until 80% markers were excreted. In barium suspension method, the patient swallowed up to 50 ml of 200% (w/v) barium meal. The abdominal radiographs were taken at the same time point as the former. Results: The total or segmental colonic transit time were obviously prolonged in all patients. Segmental transits time spent in the right colon, left colon and rectosigmoid for radiopaque markers and barium suspension method was, respectively, 30 ± 6 h and 34 ± 7 h; 38 ± 9 h and 32 ± 6 h; 40 ± 8 h and 38 ± 10 h. In the radiopaque markers method, total colonic transit time was 108 ± 14 h and it was 103 ± 13 h in the barium suspension method (P > 0.05). Conclusion: The barium suspension and radiopaque markers gave the similar results for colonic transit time. The barium suspension was a simple and cheap method for evaluating the colonic mobility.

  15. The effects of hypercapnia on cortical capillary transit time heterogeneity (CTH) in anesthetized mice

    DEFF Research Database (Denmark)

    Gutiérrez-Jiménez, Eugenio; Angleys, Hugo; Rasmussen, Peter Mondrup

    2018-01-01

    Capillary flow patterns are highly heterogeneous in the resting brain. During hyperemia, capillary transit-time heterogeneity (CTH) decreases, in proportion to blood's mean transit time (MTT) in passive, compliant microvascular networks. Previously, we found that functional activation reduces...

  16. Effects of snowmelt on watershed transit time distributions

    Science.gov (United States)

    Fang, Z.; Carroll, R. W. H.; Harman, C. J.; Wilusz, D. C.; Schumer, R.

    2017-12-01

    Snowmelt is the principal control of the timing and magnitude of water flow through alpine watersheds, but the streamflow generated may be displaced groundwater. To quantify this effect, we use a rank StorAge Selection (rSAS) model to estimate time-dependent travel time distributions (TTDs) for the East River Catchment (ERC, 84 km2) - a headwater basin of the Colorado River, and newly designated as the Lawrence Berkeley National Laboratory's Watershed Function Science Focus Area (SFA). Through the SFA, observational networks related to precipitation and stream fluxes have been established with a focus on environmental tracers and stable isotopes. The United Stated Geological Survey Precipitation Runoff Modeling System (PRMS) was used to estimate spatially- and temporally-variable boundary fluxes of effective precipitation (snowmelt & rain), evapotranspiration, and subsurface storage. The DiffeRential Evolution Adaptive Metropolis (DREAM) algorithm was used to calibrate the rSAS model to observed stream isotopic concentration data and quantify uncertainty. The sensitivity of the simulated TTDs to systematic changes in the boundary fluxes was explored. Different PRMS and rSAS model parameters setup were tested to explore how they affect the relationship between input precipitation, especially snowmelt, and the estimated TTDs. Wavelet Coherence Analysis (WCA) was applied to investigate the seasonality of TTD simulations. Our ultimate goal is insight into how the Colorado River headwater catchments store and route water, and how sensitive flow paths and transit times are to climatic changes.

  17. A methodology for rearranging transit stops for enhancing transit users generalized travel time

    Directory of Open Access Journals (Sweden)

    Mohammad Nurul Hassan

    2017-02-01

    Full Text Available This study develops a methodology to consolidate transit stops. It develops a mathematical model and a program which takes stop consolidation decision(s according to users generalized travel time savings and desired accessibility. The model iterates until the users generalized travel time savings are maximized. The study tests this mathematical model in different hypothetical scenarios. Six factors (distance between stops, passenger activity, average cruising speed, maximum walking distance, service frequency, and percentage of decreased passengers with multiple levels were set to build the scenarios. Three responses (percentage of consolidated stops, percentages of travel time and operating time savings were observed. The findings showed that the distance between the stops the passenger activity, and the probable demand change (or the percentage of decreased passengers are the most influential factors. The frequency of service was found to be influential as well. The average cruising speed has very little influence on the response variables. Finally, the model is tested on two routes (route 900 and 930 of Al Ain City public bus service. It shows that 22 and 32 out of 98 and 126 stops can be consolidated in route 900 and 930 respectively. This can save considerable amounts of users travel and operating times. In monetary values, the savings are about $329,827 and $491,094 per year for routes 900 and 930, respectively.

  18. Uncertainty analysis of power monitoring transit time ultrasonic flow meters

    International Nuclear Information System (INIS)

    Orosz, A.; Miller, D. W.; Christensen, R. N.; Arndt, S.

    2006-01-01

    A general uncertainty analysis is applied to chordal, transit time ultrasonic flow meters that are used in nuclear power plant feedwater loops. This investigation focuses on relationships between the major parameters of the flow measurement. For this study, mass flow rate is divided into three components, profile factor, density, and a form of volumetric flow rate. All system parameters are used to calculate values for these three components. Uncertainty is analyzed using a perturbation method. Sensitivity coefficients for major system parameters are shown, and these coefficients are applicable to a range of ultrasonic flow meters used in similar applications. Also shown is the uncertainty to be expected for density along with its relationship to other system uncertainties. One other conclusion is that pipe diameter sensitivity coefficients may be a function of the calibration technique used. (authors)

  19. Daylight savings time transitions and the incidence rate of unipolar depressive episodes

    DEFF Research Database (Denmark)

    Hansen, Bertel T; Sønderskov, Kim M; Hageman, Ida

    2017-01-01

    Background: Daylight savings time transitions affect approximately 1.6 billion people worldwide. Prior studies have documented associations between daylight savings time transitions and adverse health outcomes, but it remains unknown whether they also cause an increase in the incidence rate...... of depressive episodes. This seems likely because daylight savings time transitions affect circadian rhythms, which are implicated in the etiology of depressive disorder. Therefore, we investigated the effects of daylight savings time transitions on the incidence rate of unipolar depressive episodes. Methods...

  20. Water Storage, Mixing and Transit Times During a Multiyear Drought.

    Science.gov (United States)

    Van der Velde, Y.; Visser, A.; Thaw, M.; Safeeq, M.

    2017-12-01

    From 2012 to 2016, a five year intensive drought occurred in the Californian Sierra Nevada. We use this drought period as an opportunity to investigate how catchment water storage, mixing and transit times changes from wet to dry conditions using long term datasets of river discharge, evapotranspiration, water quality, and multiple cosmogenic radioactive isotopes. Characteristic features of the test catchment (4.6 km2 , altitude 1660-2117 m) include a thick (>5m) unsaturated zone in deeply weathered granite mountain soils, snow melt and events of high intensity rainfall, dry summers and numerous wetland meadows along the stream. Our data and model analysis suggest that under drought conditions, river flow predominantly consist of deep groundwater tapped by deeply incised sections of the stream, while the wetlands hold on to their water just below the root system of its shallow rooting vegetation. In contrast, during wet periods, most runoff is generated on the flat riparian wetland meadows, while the regional groundwater system slowly refills itself as water makes its way through the thick unsaturated zones. Antecedent wet or dry years play an crucial role as antecedent wet years cause a substantial regional groundwater flow towards the riparian wetlands, filling up the riparian wetlands and yielding a much stronger discharge response of the wetlands to rainfall events than under antecedent dry years This interaction between the regional groundwater system and the local wetland systems weakens as the drought progresses and regional groundwater flow to the wetlands lessens. Although, due to the wet events in 2016-2017, the catchment fills up rapidly to pre-drought conditions, we show that water transit times and therefore likely the water quality will contain drought signs for several years to come. 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- XXXXXX

  1. Transit-Time Damping, Landau Damping, and Perturbed Orbits

    Science.gov (United States)

    Simon, A.; Short, R. W.

    1997-11-01

    Transit-time damping(G.J. Morales and Y.C. Lee, Phys. Rev. Lett. 33), 1534 (1974).*^,*(P.A. Robinson, Phys. Fluids B 3), 545 (1991).** has traditionally been obtained by calculating the net energy gain of transiting electrons, of velocity v, to order E^2* in the amplitude of a localized electric field. This necessarily requires inclusion of the perturbed orbits in the equation of motion. A similar method has been used by others(D.R. Nicholson, Introduction to Plasma Theory) (Wiley, 1983).*^,*(E.M. Lifshitz and L.P. Pitaevskifi, Physical Kinetics) (Pergamon, 1981).** to obtain a ``physical'' picture of Landau damping in a nonlocalized field. The use of perturbed orbits seems odd since the original derivation of Landau (and that of Dawson) never went beyond a linear picture of the dynamics. We introduce a novel method that takes advantage of the time-reversal invariance of the Vlasov equation and requires only the unperturbed orbits to obtain the result. Obviously, there is much reduction in complexity. Application to finite slab geometry yields a simple expression for the damping rate. Equivalence to much more complicated results^2* is demonstrated. This method allows us to calculate damping in more complicated geometries and more complex electric fields, such as occur in SRS in filaments. See accompanying talk.(R.W. Short and A. Simon, this conference.) This work was supported by the U.S. DOE Office of Inertial Confinement Fusion under Co-op Agreement No. DE-FC03-92SF19460.

  2. Fuzzy Logic based Handoff Latency Reduction Mechanism in Layer 2 of Heterogeneous Mobile IPv6 Networks

    Science.gov (United States)

    Anwar, Farhat; Masud, Mosharrof H.; Latif, Suhaimi A.

    2013-12-01

    Mobile IPv6 (MIPv6) is one of the pioneer standards that support mobility in IPv6 environment. It has been designed to support different types of technologies for providing seamless communications in next generation network. However, MIPv6 and subsequent standards have some limitations due to its handoff latency. In this paper, a fuzzy logic based mechanism is proposed to reduce the handoff latency of MIPv6 for Layer 2 (L2) by scanning the Access Points (APs) while the Mobile Node (MN) is moving among different APs. Handoff latency occurs when the MN switches from one AP to another in L2. Heterogeneous network is considered in this research in order to reduce the delays in L2. Received Signal Strength Indicator (RSSI) and velocity of the MN are considered as the input of fuzzy logic technique. This technique helps the MN to measure optimum signal quality from APs for the speedy mobile node based on fuzzy logic input rules and makes a list of interfaces. A suitable interface from the list of available interfaces can be selected like WiFi, WiMAX or GSM. Simulation results show 55% handoff latency reduction and 50% packet loss improvement in L2 compared to standard to MIPv6.

  3. Fuzzy Logic based Handoff Latency Reduction Mechanism in Layer 2 of Heterogeneous Mobile IPv6 Networks

    International Nuclear Information System (INIS)

    Anwar, Farhat; Masud, Mosharrof H; Latif, Suhaimi A

    2013-01-01

    Mobile IPv6 (MIPv6) is one of the pioneer standards that support mobility in IPv6 environment. It has been designed to support different types of technologies for providing seamless communications in next generation network. However, MIPv6 and subsequent standards have some limitations due to its handoff latency. In this paper, a fuzzy logic based mechanism is proposed to reduce the handoff latency of MIPv6 for Layer 2 (L2) by scanning the Access Points (APs) while the Mobile Node (MN) is moving among different APs. Handoff latency occurs when the MN switches from one AP to another in L2. Heterogeneous network is considered in this research in order to reduce the delays in L2. Received Signal Strength Indicator (RSSI) and velocity of the MN are considered as the input of fuzzy logic technique. This technique helps the MN to measure optimum signal quality from APs for the speedy mobile node based on fuzzy logic input rules and makes a list of interfaces. A suitable interface from the list of available interfaces can be selected like WiFi, WiMAX or GSM. Simulation results show 55% handoff latency reduction and 50% packet loss improvement in L2 compared to standard to MIPv6

  4. Handoff Between a Wireless Local Area Network (WLAN and a Wide Area Network (UMTS

    Directory of Open Access Journals (Sweden)

    J. Sánchez–García

    2009-04-01

    Full Text Available With the appearance of wireless data networks with variable coverage, band width and handoff strategies, in addition to the growing need of mobile nodes to freely roam among these networks, the support of an interoperable handoff strategy for hybrid wireless data networks is a requirement that needs to be addressed. The current trend in wireless data networks is to offer multimedia access to mobile users by employing the wireless local area network (WLAN standard IEEE802.11 while the user is located indoors; on the other hand, 3rd generation wireless networks (WAN are being deployed to provide coverage while the user is located outdoors. As a result, the mobile node will require a handoff mechanism to allow the user to roam between WLAN and WAN environments; up to this date several strategies have been proposed (Sattari et al., 2004 and HyoJin, 2007 in the literature, however, none of these have been standardized to date. To support this interoperability, the mobile node must be equipped with configurable wireless inetrfaces to support the handoff between the WLAN and the WAN networks. In this work a new algorithm is proposed to allow a mobile node to roam between a wireless local area network (IEEE802.11 and a WAN base station (UMTS, while employing IP mobility support. The algorithm is implemented in simulation, using the Network Simulator 2.

  5. Practicing Handoffs Early: Applying a Clinical Framework in the Anatomy Laboratory

    Science.gov (United States)

    Lazarus, Michelle D.; Dos Santos, Jason A.; Haidet, Paul M.; Whitcomb, Tiffany L.

    2016-01-01

    The anatomy laboratory provides an ideal environment for the integration of clinical contexts as the willed-donor is often regarded as a student's "first patient." This study evaluated an innovative approach to peer teaching in the anatomy laboratory using a clinical handoff context. The authors introduced the "Situation,…

  6. A Spectrum Handoff Scheme for Optimal Network Selection in NEMO Based Cognitive Radio Vehicular Networks

    Directory of Open Access Journals (Sweden)

    Krishan Kumar

    2017-01-01

    Full Text Available When a mobile network changes its point of attachments in Cognitive Radio (CR vehicular networks, the Mobile Router (MR requires spectrum handoff. Network Mobility (NEMO in CR vehicular networks is concerned with the management of this movement. In future NEMO based CR vehicular networks deployment, multiple radio access networks may coexist in the overlapping areas having different characteristics in terms of multiple attributes. The CR vehicular node may have the capability to make call for two or more types of nonsafety services such as voice, video, and best effort simultaneously. Hence, it becomes difficult for MR to select optimal network for the spectrum handoff. This can be done by performing spectrum handoff using Multiple Attributes Decision Making (MADM methods which is the objective of the paper. The MADM methods such as grey relational analysis and cost based methods are used. The application of MADM methods provides wider and optimum choice among the available networks with quality of service. Numerical results reveal that the proposed scheme is effective for spectrum handoff decision for optimal network selection with reduced complexity in NEMO based CR vehicular networks.

  7. The Role of Electronic Health Records in Structuring Nursing Handoff Communication and Maintaining Situation Awareness

    Science.gov (United States)

    Alghenaimi, Said

    2012-01-01

    In healthcare institutions, work must continue 24 hours a day, 7 days a week. A team of nurses is needed to provide around-the-clock patient care, and this process requires transfer of patient care responsibilities, a process known as a "handoff." The present study explored the role of electronic health records in structuring handoff…

  8. Transit time homogenization in ischemic stroke - A novel biomarker of penumbral microvascular failure?

    DEFF Research Database (Denmark)

    Engedal, Thorbjørn S; Hjort, Niels; Hougaard, Kristina D

    2017-01-01

    Cerebral ischemia causes widespread capillary no-flow in animal studies. The extent of microvascular impairment in human stroke, however, is unclear. We examined how acute intra-voxel transit time characteristics and subsequent recanalization affect tissue outcome on follow-up MRI in a historic...... cohort of 126 acute ischemic stroke patients. Based on perfusion-weighted MRI data, we characterized voxel-wise transit times in terms of their mean transit time (MTT), standard deviation (capillary transit time heterogeneity - CTH), and the CTH:MTT ratio (relative transit time heterogeneity), which...... tissue, prolonged mean transit time (>5 seconds) and very low cerebral blood flow (≤6 mL/100 mL/min) was associated with high risk of infarction, largely independent of recanalization status. In the remaining mismatch region, low relative transit time heterogeneity predicted subsequent infarction...

  9. Colonic transit time is related to bacterial metabolism and mucosal turnover in the human gut

    DEFF Research Database (Denmark)

    Roager, Henrik Munch; Hansen, Lea Benedicte Skov; Bahl, Martin Iain

    Little is known about how colonic transit time relates to human colonic metabolism, and its importance for host health, although stool consistency, a proxy for colonic transit time, has recently been negatively associated with gut microbial richness. To address the relationships between colonic t...... imply a healthy gut microbial ecosystem and points at colonic transit time as a highly important factor to consider in microbiome and metabolomics studies.......Little is known about how colonic transit time relates to human colonic metabolism, and its importance for host health, although stool consistency, a proxy for colonic transit time, has recently been negatively associated with gut microbial richness. To address the relationships between colonic...... transit time and the gut microbial composition and metabolism, we assessed the colonic transit time of 98 subjects using radiopaque markers, and profiled their gut microbiota by16S rRNA gene sequencing and their urine metabolome by ultra performance liquid chromatography mass spectrometry. Based...

  10. Colonic transit time and pressure based on Bernoulli's principle.

    Science.gov (United States)

    Uno, Yoshiharu

    2018-01-01

    Variations in the caliber of human large intestinal tract causes changes in pressure and the velocity of its contents, depending on flow volume, gravity, and density, which are all variables of Bernoulli's principle. Therefore, it was hypothesized that constipation and diarrhea can occur due to changes in the colonic transit time (CTT), according to Bernoulli's principle. In addition, it was hypothesized that high amplitude peristaltic contractions (HAPC), which are considered to be involved in defecation in healthy subjects, occur because of cecum pressure based on Bernoulli's principle. A virtual healthy model (VHM), a virtual constipation model and a virtual diarrhea model were set up. For each model, the CTT was decided according to the length of each part of the colon, and then calculating the velocity due to the cecum inflow volume. In the VHM, the pressure change was calculated, then its consistency with HAPC was verified. The CTT changed according to the difference between the cecum inflow volume and the caliber of the intestinal tract, and was inversely proportional to the cecum inflow volume. Compared with VHM, the CTT was prolonged in the virtual constipation model, and shortened in the virtual diarrhea model. The calculated pressure of the VHM and the gradient of the interlocked graph were similar to that of HAPC. The CTT and HAPC can be explained by Bernoulli's principle, and constipation and diarrhea may be fundamentally influenced by flow dynamics.

  11. Prognosis of constipation: clinical factors and colonic transit time

    Science.gov (United States)

    de Lorijn, F; van Wijk, M P; Reitsma, J; van Ginkel, R; Taminiau, J; Benninga, M

    2004-01-01

    Background: Measurement of colonic transit time (CTT) is sometimes used in the evaluation of patients with chronic constipation. Aim: To investigate the relation between symptoms and CTT, and to assess the importance of symptoms and CTT in predicting outcome. Methods: Between 1995 and 2000, 169 consecutive patients (median age 8.4 years, 65% boys) fulfilling the criteria for constipation were enrolled. During the intervention and follow up period, all kept a diary to record symptoms. CTT was measured at entry to the study. Results: At entry, defecation frequency was lower in girls than in boys, while the frequency of encopresis episodes was higher in boys. CTT values were significantly higher in those with a low defecation frequency (⩽1/week) and a high frequency of encopresis (⩾2/day). However, 50% had CTT values within the normal range. Successful outcome occurred more often in those with a rectal impaction. CTT results 100 hours were less likely to have had a successful outcome. Conclusion: The presence of a rectal impaction at presentation is associated with a better outcome at one year. A CTT >100 hours is associated with a poor outcome at one year. PMID:15269069

  12. Modeling and Analysis of Hybrid Cellular/WLAN Systems with Integrated Service-Based Vertical Handoff Schemes

    Science.gov (United States)

    Xia, Weiwei; Shen, Lianfeng

    We propose two vertical handoff schemes for cellular network and wireless local area network (WLAN) integration: integrated service-based handoff (ISH) and integrated service-based handoff with queue capabilities (ISHQ). Compared with existing handoff schemes in integrated cellular/WLAN networks, the proposed schemes consider a more comprehensive set of system characteristics such as different features of voice and data services, dynamic information about the admitted calls, user mobility and vertical handoffs in two directions. The code division multiple access (CDMA) cellular network and IEEE 802.11e WLAN are taken into account in the proposed schemes. We model the integrated networks by using multi-dimensional Markov chains and the major performance measures are derived for voice and data services. The important system parameters such as thresholds to prioritize handoff voice calls and queue sizes are optimized. Numerical results demonstrate that the proposed ISHQ scheme can maximize the utilization of overall bandwidth resources with the best quality of service (QoS) provisioning for voice and data services.

  13. Gastrointestinal mean transit times in young and middle-aged healthy subjects

    DEFF Research Database (Denmark)

    Graff, J; Brinch, K; Madsen, Jan Lysgård

    2001-01-01

    To investigate the effects of age and gender on gastric, small intestinal and colonic mean transit times, a study was conducted in 32 healthy volunteers: eight young women (22-30 years), eight young men (20-28 years), eight middle-aged women (43-51 years) and eight middle-aged men (38-53 years......, small intestinal and colonic mean transit times were calculated. The gastric, small intestinal and colonic mean transit times were significantly longer in women. Ageing was shown to accelerate the gastric and small intestinal transit significantly. In the group of men the colonic mean transit time...... was unaffected by age, but middle-aged women had a significantly slower colonic transit than young women. We therefore conclude that both age and gender have to be considered when reference values for gastric, small intestinal and colonic mean transit times have to be established....

  14. Alteration of gastrointestinal transit time in the rat after bile duct cannulation surgery

    International Nuclear Information System (INIS)

    Ayres, P.H.; Medinsky, M.A.; Muggenburg, B.A.; Bond, J.A.

    1985-01-01

    Alteration of gastrointestinal (GI) transit time could affect the bioavailability of a toxicant if the toxicant is absorbed in the GI tract. The effect of surgery on GI transit time was investigated using radiographic imaging of barium during passage through the GI tract of the rat. Bile duct cannulation surgery delayed transit of barium to over 18 h, whereas in the normal animal, transit required approximately 6 h. GI transit time was only moderately affected by laparotomy after an 18-h postsurgery recovery period. These results suggest that the gastrointestinal absorption of orally administered toxicants could be affected by bile duct cannulation. 3 references, 1 figure, 1 table

  15. Assessment of chronic constipation: colon transit time versus defecography

    International Nuclear Information System (INIS)

    Prokesch, R.W.; Breitenseher, M.J.; Kettenbach, J.; Herbst, F.; Maier, A.; Lechner, G.; Mahieu, P.

    1999-01-01

    Objective: The aim of this study was to determine the value of radiological colon transit time (CTT) measurements in relation to defecography (DFG) in chronically constipated patients. Materials and methods: In 30 patients with chronic constipation, total and segmental CTT was determined using radiopaque markers. In all of these patients defecography (DFG) was obtained. The patients were divided into three groups: In group I, 11 patients were classified with idiopathic constipation based on low stool frequency, normal DFG, or absence of symptoms of abnormal defecation. In group II, ten patients with rectal intussusception were diagnosed by DFG. In group III, there were nine patients with rectal prolapse or spastic pelvic floor syndrome, based on results of DFG. Results: Group I, idiopathic constipation (n=11), showed increased total CTT (mean, 93 h) and segmental CTT (right colon, 33 h (36%), left colon, 31 h (33%), rectosigmoid, 29 h (31%)). In group II, intussusception (n=10), patients had normal mean total CTT (54 h) and a relative decrease in rectosigmoid CTT (mean, 13 h (24%)). In group III (n=9), rectal prolapse (n=5) or spastic pelvic floor syndrome (n=4), patients showed elevated total (mean, 167 h) and rectosigmoidal CTT (mean, 95 h (57%)). Mean total CTT was significantly different between groups I and II and between groups II and III, and mean rectosigmoidal CTT was significantly different between all three groups (P<0.05). Conclusion: The use of total and rectosigmoidal CTT helps to identify the underlying pathophysiology of chronic constipation. Furthermore CTT helps to identify patients, who may benefit from DFG

  16. Assessment of chronic constipation: colon transit time versus defecography

    Energy Technology Data Exchange (ETDEWEB)

    Prokesch, R.W. E-mail: rupert.prokesch@univie.ac.at; Breitenseher, M.J.; Kettenbach, J.; Herbst, F.; Maier, A.; Lechner, G.; Mahieu, P

    1999-12-01

    Objective: The aim of this study was to determine the value of radiological colon transit time (CTT) measurements in relation to defecography (DFG) in chronically constipated patients. Materials and methods: In 30 patients with chronic constipation, total and segmental CTT was determined using radiopaque markers. In all of these patients defecography (DFG) was obtained. The patients were divided into three groups: In group I, 11 patients were classified with idiopathic constipation based on low stool frequency, normal DFG, or absence of symptoms of abnormal defecation. In group II, ten patients with rectal intussusception were diagnosed by DFG. In group III, there were nine patients with rectal prolapse or spastic pelvic floor syndrome, based on results of DFG. Results: Group I, idiopathic constipation (n=11), showed increased total CTT (mean, 93 h) and segmental CTT (right colon, 33 h (36%), left colon, 31 h (33%), rectosigmoid, 29 h (31%)). In group II, intussusception (n=10), patients had normal mean total CTT (54 h) and a relative decrease in rectosigmoid CTT (mean, 13 h (24%)). In group III (n=9), rectal prolapse (n=5) or spastic pelvic floor syndrome (n=4), patients showed elevated total (mean, 167 h) and rectosigmoidal CTT (mean, 95 h (57%)). Mean total CTT was significantly different between groups I and II and between groups II and III, and mean rectosigmoidal CTT was significantly different between all three groups (P<0.05). Conclusion: The use of total and rectosigmoidal CTT helps to identify the underlying pathophysiology of chronic constipation. Furthermore CTT helps to identify patients, who may benefit from DFG.

  17. A Comparison of Techniques for Camera Selection and Hand-Off in a Video Network

    Science.gov (United States)

    Li, Yiming; Bhanu, Bir

    Video networks are becoming increasingly important for solving many real-world problems. Multiple video sensors require collaboration when performing various tasks. One of the most basic tasks is the tracking of objects, which requires mechanisms to select a camera for a certain object and hand-off this object from one camera to another so as to accomplish seamless tracking. In this chapter, we provide a comprehensive comparison of current and emerging camera selection and hand-off techniques. We consider geometry-, statistics-, and game theory-based approaches and provide both theoretical and experimental comparison using centralized and distributed computational models. We provide simulation and experimental results using real data for various scenarios of a large number of cameras and objects for in-depth understanding of strengths and weaknesses of these techniques.

  18. Analysis of handoff strategies in macro-femto cells environment based on per-energy capacity

    KAUST Repository

    Leon, Jaime; Bader, Faouzi; Alouini, Mohamed-Slim

    2012-01-01

    Placing smaller cells in a heterogeneous network can be beneficial in terms of energy because better capacities can be obtained for a given energy constraint. These type of deployments not only highlight the need for appropriate metrics to evaluate how well energy is being spent, but also raise important issues that need to be taken into account when analysing the overall use of energy. In this study, handoff strategies, bandwidth allocation and path loss calculations in different scenarios, illustrate how energy can be consumed in a more efficient way when cell size is decreased. As a result, users can experience higher capacities while spending less energy, depending whether they handoff or not, increasing the overall performance of the network. © 2012 The Institution of Engineering and Technology.

  19. EAP-Kerberos: A Low Latency EAP Authentication Method for Faster Handoffs in Wireless Access Networks

    Science.gov (United States)

    Zrelli, Saber; Okabe, Nobuo; Shinoda, Yoichi

    The wireless medium is a key technology for enabling ubiquitous and continuous network connectivity. It is becoming more and more important in our daily life especially with the increasing adoption of networking technologies in many fields such as medical care and transportation systems. Although most wireless technologies nowadays provide satisfying bandwidth and higher speeds, several of these technologies still lack improvements with regard to handoff performance. In this paper, we focus on wireless network technologies that rely on the Extensible Authentication Protocol for mutual authentication between the station and the access network. Such technologies include local area wireless networks (IEEE 802.11) as well as broadband wireless networks (IEEE 802.16). We present a new EAP authentication method based on a three party authentication scheme, namely Kerberos, that considerably shortens handoff delays. Compared to other methods, the proposed method has the advantage of not requiring any changes on the access points, making it readily deployable at reasonable costs.

  20. Mobile physician reporting of clinically significant events-a novel way to improve handoff communication and supervision of resident on call activities.

    Science.gov (United States)

    Nabors, Christopher; Peterson, Stephen J; Aronow, Wilbert S; Sule, Sachin; Mumtaz, Arif; Shah, Tushar; Eskridge, Etta; Wold, Eric; Stallings, Gary W; Burak, Kathleen Kelly; Goldberg, Randy; Guo, Gary; Sekhri, Arunabh; Mathew, George; Khera, Sahil; Montoya, Jessica; Sharma, Mala; Paudel, Rajiv; Frishman, William H

    2014-12-01

    Reporting of clinically significant events represents an important mechanism by which patient safety problems may be identified and corrected. However, time pressure and cumbersome report entry procedures have discouraged the full participation of physicians. To improve the process, our internal medicine training program developed an easy-to-use mobile platform that combines the reporting process with patient sign-out. Between August 25, 2011, and January 25, 2012, our trainees entered clinically significant events into i-touch/i-phone/i-pad based devices functioning in wireless-synchrony with our desktop application. Events were collected into daily reports that were sent from the handoff system to program leaders and attending physicians to plan for rounds and to correct safety problems. Using the mobile module, residents entered 31 reportable events per month versus the 12 events per month that were reported via desktop during a previous 6-month study period. Advances in information technology now permit clinically significant events that take place during "off hours" to be identified and reported (via handoff) to next providers and to supervisors via collated reports. This information permits hospital leaders to correct safety issues quickly and effectively, while attending physicians are able to use information gleaned from the reports to optimize rounding plans and to provide additional oversight of trainee on call patient management decisions.

  1. Transit Timing Observations from Kepler: III. Confirmation of 4 Multiple Planet Systems by a Fourier-Domain Study of Anti-correlated Transit Timing Variations

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason H.; /Fermilab; Fabrycky, Daniel C.; /Lick Observ.; Ford, Eric B.; /Florida U.; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Fressin, Francois; /Harvard-Smithsonian Ctr. Astrophys.; Holman, Matthew J.; /Harvard-Smithsonian Ctr. Astrophys.; Lissauer, Jack J.; /NASA, Ames; Rowe, Jason F.; /SETI Inst., Mtn. View /NASA, Ames; Ragozzine, Darin; /Harvard-Smithsonian Ctr. Astrophys.; Welsh, William F.; /Caltech; Borucki, William J.; /NASA, Ames /UC, Santa Barbara

    2012-01-01

    We present a method to confirm the planetary nature of objects in systems with multiple transiting exoplanet candidates. This method involves a Fourier-domain analysis of the deviations in the transit times from a constant period that result from dynamical interactions within the system. The combination of observed anticorrelations in the transit times and mass constraints from dynamical stability allow us to claim the discovery of four planetary systems, Kepler-25, Kepler-26, Kepler-27 and Kepler-28, containing eight planets and one additional planet candidate.

  2. Pharyngeal transit time measured by scintigraphic and biomagnetic method

    International Nuclear Information System (INIS)

    Miquelin, C.A.; Braga, F.J.H.N.; Baffa, O.

    1996-01-01

    A comparative evaluation between scintigraphic and biomagnetic method to measure the pharyngeal transit is presented. Three volunteers have been studied. The aliment (yogurt) was labeled with 9 9 m Technetium for the scintigraphic test and with ferrite for the biomagnetic one. The preliminary results indicate a difference between the values obtained, probably due to the biomagnetic detector resolution

  3. Decreasing Transition Times in Elementary School Classrooms: Using Computer-Assisted Instruction to Automate Intervention Components

    Science.gov (United States)

    Hine, Jeffrey F.; Ardoin, Scott P.; Foster, Tori E.

    2015-01-01

    Research suggests that students spend a substantial amount of time transitioning between classroom activities, which may reduce time spent academically engaged. This study used an ABAB design to evaluate the effects of a computer-assisted intervention that automated intervention components previously shown to decrease transition times. We examined…

  4. Nano-optical conveyor belt, part II: Demonstration of handoff between near-field optical traps.

    Science.gov (United States)

    Zheng, Yuxin; Ryan, Jason; Hansen, Paul; Cheng, Yao-Te; Lu, Tsung-Ju; Hesselink, Lambertus

    2014-06-11

    Optical tweezers have been widely used to manipulate biological and colloidal material, but the diffraction limit of far-field optics makes focused beams unsuitable for manipulating nanoscale objects with dimensions much smaller than the wavelength of light. While plasmonic structures have recently been successful in trapping nanoscale objects with high positioning accuracy, using such structures for manipulation over longer range has remained a significant challenge. In this work, we introduce a conveyor belt design based on a novel plasmonic structure, the resonant C-shaped engraving (CSE). We show how long-range manipulation is made possible by means of handoff between neighboring CSEs, and we present a simple technique for controlling handoff by rotating the polarization of laser illumination. We experimentally demonstrate handoff between a pair of CSEs for polystyrene spheres 200, 390, and 500 nm in diameter. We then extend this technique and demonstrate controlled particle transport down a 4.5 μm long "nano-optical conveyor belt."

  5. Regional Gastrointestinal Transit Times in Patients With Carcinoid Diarrhea: Assessment With the Novel 3D-Transit System.

    Science.gov (United States)

    Gregersen, Tine; Haase, Anne-Mette; Schlageter, Vincent; Gronbaek, Henning; Krogh, Klaus

    2015-07-30

    The paucity of knowledge regarding gastrointestinal motility in patients with neuroendocrine tumors and carcinoid diarrhea re-stricts targeted treatment. 3D-Transit is a novel, minimally invasive, ambulatory method for description of gastrointestinal motility. The system has not yet been evaluated in any group of patients. We aimed to test the performance of 3D-Transit in patients with carcinoid diarrhea and to compare the patients' regional gastrointestinal transit times (GITT) and colonic motility patterns with those of healthy subjects. Fifteen healthy volunteers and seven patients with neuroendocrine tumor and at least 3 bowel movements per day were inves-tigated with 3D-Transit and standard radiopaque markers. Total GITT assessed with 3D-Transit and radiopaque markers were well correlated (Spearman's rho = 0.64, P = 0.002). Median total GITT was 12.5 (range: 8.5-47.2) hours in patients versus 25.1 (range: 13.1-142.3) hours in healthy (P = 0.007). There was no difference in gastric emptying (P = 0.778). Median small intestinal transit time was 3.8 (range: 1.4-5.5) hours in patients versus 4.4 (range: 1.8-7.2) hours in healthy subjects (P = 0.044). Median colorectal transit time was 5.2 (range: 2.9-40.1) hours in patients versus 18.1 (range: 5.0-134.0) hours in healthy subjects (P = 0.012). Median frequency of pansegmental co-lonic movements was 0.45 (range: 0.03-1.02) per hour in patients and 0.07 (range: 0-0.61) per hour in healthy subjects (P = 0.045). Three-dimensional Transit allows assessment of regional GITT in patients with diarrhea. Patients with carcinoid diarrhea have faster than normal gastrointestinal transit due to faster small intestinal and colorectal transit times. The latter is caused by an increased frequency of pansegmental colonic movements.

  6. Transition in adolescents across time, disease and gender

    DEFF Research Database (Denmark)

    Svanholm, Jette Rolf; Ludvigsen, Mette Spliid; Aagaard, Hanne

    University, Denmark Jeanette.Svanholm@skejby.rm.dk, Mette.Ludvigsen@skejby.rm.dk, Hanne.Aagaard@skejby.rm.dk Background: Adolescents do not get involved in the preparation and planning of their health care transition, which leaves them with negative experiences and feelings of not having their health care......’ with congenial heart diseases, chronic kidney diseases and cystic fibrosis perspective. Objective: To study experiences of transition in adolescents with severe chronic diseases in the context of child-centred health care to adult-centred health care Research questions: • What are the adolescents’ experiences...... study, longitudinal design • systematic literature search • ethnographic fieldwork (Hammersley, Atkinson 2007) o participant observations of consultations between adolescents and health care staff o individual semi-structured interviews with the adolescents (Kvale, Brinkmann 2009). Participants...

  7. NO TIMING VARIATIONS OBSERVED IN THIRD TRANSIT OF SNOW-LINE EXOPLANET KEPLER-421b

    International Nuclear Information System (INIS)

    Dalba, Paul A.; Muirhead, Philip S.

    2016-01-01

    We observed Kepler-421 during the anticipated third transit of the snow-line exoplanet Kepler-421b in order to constrain the existence and extent of transit timing variations (TTVs). Previously, the Kepler spacecraft only observed two transits of Kepler-421b, leaving the planet’s transit ephemeris unconstrained. Our visible light, time-series observations from the 4.3 m Discovery Channel Telescope were designed to capture pre-transit baseline and the partial transit of Kepler-421b, barring significant TTVs. We use the light curves to assess the probabilities of various transit models using both the posterior odds ratio and the Bayesian Information Criterion, and find that a transit model with no TTVs is favored to 3.6 σ confidence. These observations suggest that Kepler-421b is either alone in its system or is only experiencing minor dynamic interactions with an unseen companion. With the Kepler-421b ephemeris constrained, we calculate future transit times and discuss the opportunity to characterize the atmosphere of this cold, long-period exoplanet via transmission spectroscopy. Our investigation emphasizes the difficulties associated with observing long-period exoplanet transits and the consequences that arise from failing to refine transit ephemerides.

  8. How many segments are necessary to characterize delayed colonic transit time?

    Science.gov (United States)

    Bouchoucha, Michel; Devroede, Ghislain; Bon, Cyriaque; Raynaud, Jean-Jacques; Bejou, Bakhtiar; Benamouzig, Robert

    2015-10-01

    Measuring colonic transit time with radiopaque markers is simple, inexpensive, and very useful in constipated patients. Yet, the algorithm used to identify colonic segments is subjective, rather than founded on prior experimentation. The aim of the present study is to describe a rational way to determine the colonic partition in the measurement of colonic transit time. Colonic transit time was measured in seven segments: ascending colon, hepatic flexure, right and left transverse colon, splenic flexure, descending colon, and rectosigmoid in 852 patients with functional bowel and anorectal disorders. An unsupervised algorithm for modeling Gaussian mixtures served to estimate the number of subgroups from this oversegmented colonic transit time. After that, we performed a k-means clustering that separated the observations into homogenous groups of patients according to their oversegmented colonic transit time. The Gaussian mixture followed by the k-means clustering defined 4 populations of patients: "normal and fast transit" (n = 548) and three groups of patients with delayed colonic transit time "right delay" (n = 82) in which transit is delayed in the right part of the colon, "left delay" (n = 87) with transit delayed in the left part of colon and "outlet constipation" (n = 135) for patients with transit delayed in the terminal intestine. Only 3.7 % of patients were "erroneously" classified in the 4 groups recognized by clustering. This unsupervised analysis of segmental colonic transit time shows that the classical division of the colon and the rectum into three segments is sufficient to characterize delayed segmental colonic transit time.

  9. Stopped-flow technique for transit time measurement in a gas jet

    International Nuclear Information System (INIS)

    Rengan, K.; Lin, J.; Lim, T.; Meyer, R.A.; Harrell, J.

    1985-01-01

    A 'stopped-flow' technique for the measurement of transit time of reaction products in a gas jet is described. The method involved establishing the gas flow through the jet system when the reactor is operating steadily and allowing the pressure to reach equilibrium values. The gas flow is stopped by means of electrically operated valves. The transit-time measurement is achieved by opening the valves and initiating the multiscanning of total activity simultaneously. The value obtained agrees well with the transit time measured by pulsing the reactor. The 'stopped-flow' technique allows on-line measurement of transit time in any gas jet system where the physical transportation time is the major component of the transit time. This technique is especially useful for systems installed in reactors which do not have pulsing capability. (orig.)

  10. The time-varying shortest path problem with fuzzy transit costs and speedup

    Directory of Open Access Journals (Sweden)

    Rezapour Hassan

    2016-08-01

    Full Text Available In this paper, we focus on the time-varying shortest path problem, where the transit costs are fuzzy numbers. Moreover, we consider this problem in which the transit time can be shortened at a fuzzy speedup cost. Speedup may also be a better decision to find the shortest path from a source vertex to a specified vertex.

  11. Nonparametric estimation in an "illness-death" model when all transition times are interval censored

    DEFF Research Database (Denmark)

    Frydman, Halina; Gerds, Thomas; Grøn, Randi

    2013-01-01

    We develop nonparametric maximum likelihood estimation for the parameters of an irreversible Markov chain on states {0,1,2} from the observations with interval censored times of 0 → 1, 0 → 2 and 1 → 2 transitions. The distinguishing aspect of the data is that, in addition to all transition times ...

  12. Integral definition of transition time in the Landau-Zener model

    International Nuclear Information System (INIS)

    Yan Yue; Wu Biao

    2010-01-01

    We give a general definition for the transition time in the Landau-Zener model. This definition allows us to compute numerically the Landau-Zener transition time at any sweeping rate without ambiguity in both diabatic and adiabatic bases. With this new definition, analytical results are obtained in both the adiabatic limit and the sudden limit.

  13. Patterns of digital volume pulse waveform and pulse transit time in ...

    African Journals Online (AJOL)

    In this study the digital volume pulse wave and the pulse transit time of the thumb and big toe were analyzed in young and older subjects some of whom were hypertensive. We aimed to study the components and patterns of the pulse waveform and the pulse transit time and how they might change. Material and Methods: ...

  14. Spin transitions in time-dependent magnetic fields

    International Nuclear Information System (INIS)

    Garisto, F.; Sanctuary, B.C.

    1981-01-01

    Nonadiabatic transitions in state-selection experiments on beams of metastable hydrogen atoms (2S/sub 1/2/) display oscillations in the population of the F=1, m=-1 state [R. D. Hight and R. T. Robiscoe, Phys. Rev. A 17, 561 (1978)]. In this paper, theoretical calculations using exact and model solenoid fields averaged over a velocity distribution show that the population oscillations arise from the presence of at least two nonadiabatic regions in the solenoid. No oscillations occur theoretically if only a single nonadiabatic region exists, unless the unlikely assumption of a coherent hydrogen-atom beam is invoked

  15. Cost-effective handoff scheme based on mobility-aware dual pointer forwarding in proxy mobile IPv6 networks.

    Science.gov (United States)

    Son, Seungsik; Jeong, Jongpil

    2014-01-01

    In this paper, a mobility-aware Dual Pointer Forwarding scheme (mDPF) is applied in Proxy Mobile IPv6 (PMIPv6) networks. The movement of a Mobile Node (MN) is classified as intra-domain and inter-domain handoff. When the MN moves, this scheme can reduce the high signaling overhead for intra-handoff/inter-handoff, because the Local Mobility Anchor (LMA) and Mobile Access Gateway (MAG) are connected by pointer chains. In other words, a handoff is aware of low mobility between the previously attached MAG (pMAG) and newly attached MAG (nMAG), and another handoff between the previously attached LMA (pLMA) and newly attached LMA (nLMA) is aware of high mobility. Based on these mobility-aware binding updates, the overhead of the packet delivery can be reduced. Also, we analyse the binding update cost and packet delivery cost for route optimization, based on the mathematical analytic model. Analytical results show that our mDPF outperforms the PMIPv6 and the other pointer forwarding schemes, in terms of reducing the total cost of signaling.

  16. Gastrointestinal mean transit times in young and middle-aged healthy subjects

    DEFF Research Database (Denmark)

    Graff, J; Brinch, K; Madsen, Jan Lysgård

    2001-01-01

    To investigate the effects of age and gender on gastric, small intestinal and colonic mean transit times, a study was conducted in 32 healthy volunteers: eight young women (22-30 years), eight young men (20-28 years), eight middle-aged women (43-51 years) and eight middle-aged men (38-53 years......). After ingestion of a meal containing 111Indium-labelled water and 99mTechnetium-labelled omelette imaging of the abdomen was performed at intervals of 30 min until all radioactivity was located in the colon and henceforth at intervals of 24 h until all radioactivity had cleared from the colon. Gastric......, small intestinal and colonic mean transit times were calculated. The gastric, small intestinal and colonic mean transit times were significantly longer in women. Ageing was shown to accelerate the gastric and small intestinal transit significantly. In the group of men the colonic mean transit time...

  17. Renewable Energy Policies in a Time of Transition

    International Nuclear Information System (INIS)

    Murdock, Hannah E.; Adib, Rana; Lins, Christine; Guerra, Flavia; Misra, Archita; Murdock, Hannah E.; Vickery, Louise; Collier, Ute; Le Feuvre, Pharoah; Bianco, Emanuele; Mueller, Simon; Philibert, Cedric; Schmidt, Oliver; Kvarnstroem, Oskar; Collier, Ute; Hungerford, Zoe; Frankl, Paolo; Bianco, Emanuele; Hawila, Diala; Ferroukhi, Rabia; Hawila, Diala; Renner, Michael; Nagpal, Divyam; Cox, Sadie; Esterly, Sean; Priesmann, Caspar; Taylor, Hadley; Breitschopf, Barbara; Van Rooijen, Sascha

    2018-01-01

    Spurred by innovation, increased competition, and policy support in a growing number of countries, renewable energy technologies have achieved massive technological advances and sharp cost reductions. Renewables have come to the forefront of the global energy transition, with nearly every country adopting a renewable energy target. Yet progress has been uneven in different countries and sectors. Technology and financial risks still hamper the expansion of renewables into new markets. As the power sector develops further, the increased adoption of variable renewables like solar and wind requires more flexible systems. Compared to power generation, the regulatory framework for end-use sectors lags behind. This report, prepared jointly by the International Renewable Energy Agency (IRENA), the International Energy Agency (IEA) and the Renewable Energy Policy Network for the 21. Century (REN21), identifies key barriers and highlights policy options to boost renewable energy deployment. After reviewing current policies and targets worldwide, it examines sector-specific policies for heating and cooling, transport and power, as well as measures for integrating variable renewables. An updated policy classification and terminology list can serve as a global reference for renewable energy policy instruments. Among the key findings: Renewable energy policies must focus on end-use sectors, not just power generation; The use of renewables for heating and cooling requires greater policy attention, including dedicated targets, technology mandates, financial incentives, generation-based incentives, and carbon or energy taxes; Policies in the transport sector require further development, including integrated policies to de-carbonise energy carriers and fuels, vehicles and infrastructure; Policies in the power sector must also evolve further to address new challenges. Measures are needed to support the integration of variable renewable energy, taking into account the specific

  18. Using the Life Satisfaction Approach to Value Daylight Savings Time Transitions: Evidence from Britain and Germany

    OpenAIRE

    Daniel Kuehnle; Christoph Wunder

    2015-01-01

    Daylight savings time (DST) represents a public good with costs and benefits. We provide the first comprehensive examination of the welfare effects of the spring and autumn transitions for the UK and Germany. Using individual-level data and a regression discontinuity design, we estimate the effect of the transitions on life satisfaction. Our results show that individuals in both the UK and Germany experience deteriorations in life satisfaction in the first week after the spring transition. We...

  19. Colonic transit time is related to bacterial metabolism and mucosal turnover in the gut

    DEFF Research Database (Denmark)

    Roager, Henrik Munch; Hansen, Lea Benedicte Skov; Bahl, Martin Iain

    2016-01-01

    Little is known about how colonic transit time relates to human colonic metabolism and its importance for host health, although a firm stool consistency, a proxy for a long colonic transit time, has recently been positively associated with gut microbial richness. Here, we show that colonic transi...... does not per se imply a healthy gut microbial ecosystem and points at colonic transit time as a highly important factor to consider in microbiome and metabolomics studies.......Little is known about how colonic transit time relates to human colonic metabolism and its importance for host health, although a firm stool consistency, a proxy for a long colonic transit time, has recently been positively associated with gut microbial richness. Here, we show that colonic transit...... time in humans, assessed using radio-opaque markers, is associated with overall gut microbial composition, diversity and metabolism. We find that a long colonic transit time associates with high microbial richness and is accompanied by a shift in colonic metabolism from carbohydrate fermentation...

  20. Time-Varying Transition Probability Matrix Estimation and Its Application to Brand Share Analysis.

    Science.gov (United States)

    Chiba, Tomoaki; Hino, Hideitsu; Akaho, Shotaro; Murata, Noboru

    2017-01-01

    In a product market or stock market, different products or stocks compete for the same consumers or purchasers. We propose a method to estimate the time-varying transition matrix of the product share using a multivariate time series of the product share. The method is based on the assumption that each of the observed time series of shares is a stationary distribution of the underlying Markov processes characterized by transition probability matrices. We estimate transition probability matrices for every observation under natural assumptions. We demonstrate, on a real-world dataset of the share of automobiles, that the proposed method can find intrinsic transition of shares. The resulting transition matrices reveal interesting phenomena, for example, the change in flows between TOYOTA group and GM group for the fiscal year where TOYOTA group's sales beat GM's sales, which is a reasonable scenario.

  1. Time-Varying Transition Probability Matrix Estimation and Its Application to Brand Share Analysis.

    Directory of Open Access Journals (Sweden)

    Tomoaki Chiba

    Full Text Available In a product market or stock market, different products or stocks compete for the same consumers or purchasers. We propose a method to estimate the time-varying transition matrix of the product share using a multivariate time series of the product share. The method is based on the assumption that each of the observed time series of shares is a stationary distribution of the underlying Markov processes characterized by transition probability matrices. We estimate transition probability matrices for every observation under natural assumptions. We demonstrate, on a real-world dataset of the share of automobiles, that the proposed method can find intrinsic transition of shares. The resulting transition matrices reveal interesting phenomena, for example, the change in flows between TOYOTA group and GM group for the fiscal year where TOYOTA group's sales beat GM's sales, which is a reasonable scenario.

  2. Topological transitions at finite temperatures: A real-time numerical approach

    International Nuclear Information System (INIS)

    Grigoriev, D.Yu.; Rubakov, V.A.; Shaposhnikov, M.E.

    1989-01-01

    We study topological transitions at finite temperatures within the (1+1)-dimensional abelian Higgs model by a numerical simulation in real time. Basic ideas of the real-time approach are presented and some peculiarities of the Metropolis technique are discussed. It is argued that the processes leading to topological transitions are of classical origin; the transitions can be observed by solving the classical field equations in real time. We show that the topological transitions actually pass via the sphaleron configuration. The transition rate as a function of temperature is found to be in good agreement with the analytical predictions. No extra suppression of the rate is observed. The conditions of applicability of our approach are discussed. The temperature interval where the low-temperature broken phase persists is estimated. (orig.)

  3. A Departure Time Choice for Morning Commute Considering Train Capacity of a Rail Transit Line

    OpenAIRE

    Jia Feng; Baohua Mao; Zhijie Chen; Yun Bai; Minggao Li

    2013-01-01

    Every commuter utilizing urban rail transit decides the departure time from home to a station according to individual judgment for the biggest possibility to board a train as soon as possible after the arrival. Therefore, the departure time choice behavior of the commuters is complicated especially when the transport capacity of this transit line cannot meet the travel demands of its users in rush hour. This research first develops a travel cost function mainly considering the travel time to ...

  4. Daylight Savings Time Transitions and the Incidence Rate of Unipolar Depressive Episodes.

    Science.gov (United States)

    Hansen, Bertel T; Sønderskov, Kim M; Hageman, Ida; Dinesen, Peter T; Østergaard, Søren D

    2017-05-01

    Daylight savings time transitions affect approximately 1.6 billion people worldwide. Prior studies have documented associations between daylight savings time transitions and adverse health outcomes, but it remains unknown whether they also cause an increase in the incidence rate of depressive episodes. This seems likely because daylight savings time transitions affect circadian rhythms, which are implicated in the etiology of depressive disorder. Therefore, we investigated the effects of daylight savings time transitions on the incidence rate of unipolar depressive episodes. Using time series intervention analysis of nationwide data from the Danish Psychiatric Central Research Register from 1995 to 2012, we compared the observed trend in the incidence rate of hospital contacts for unipolar depressive episodes after the transitions to and from summer time to the predicted trend in the incidence rate. The analyses were based on 185,419 hospital contacts for unipolar depression and showed that the transition from summer time to standard time were associated with an 11% increase (95% CI = 7%, 15%) in the incidence rate of unipolar depressive episodes that dissipated over approximately 10 weeks. The transition from standard time to summer time was not associated with a parallel change in the incidence rate of unipolar depressive episodes. This study shows that the transition from summer time to standard time was associated with an increase in the incidence rate of unipolar depressive episodes. Distress associated with the sudden advancement of sunset, marking the coming of a long period of short days, may explain this finding. See video abstract at, http://links.lww.com/EDE/B179.

  5. Time-delay-induced phase-transition to synchrony in coupled bursting neurons

    Science.gov (United States)

    Adhikari, Bhim Mani; Prasad, Awadhesh; Dhamala, Mukeshwar

    2011-06-01

    Signal transmission time delays in a network of nonlinear oscillators are known to be responsible for a variety of interesting dynamic behaviors including phase-flip transitions leading to synchrony or out of synchrony. Here, we uncover that phase-flip transitions are general phenomena and can occur in a network of coupled bursting neurons with a variety of coupling types. The transitions are marked by nonlinear changes in both temporal and phase-space characteristics of the coupled system. We demonstrate these phase-transitions with Hindmarsh-Rose and Leech-Heart interneuron models and discuss the implications of these results in understanding collective dynamics of bursting neurons in the brain.

  6. Measurement and evaluation of transit travel time reliability

    Science.gov (United States)

    2011-01-01

    Transportation system customers need consistency in their daily travel times to enable them to plan their daily : activities, whether that is a commuter on their way to work, a company setting up delivery schedules for justintime : manufacturin...

  7. Transiting Exoplanet Monitoring Project (TEMP). IV. Refined System Parameters, Transit Timing Variations, and Orbital Stability of the Transiting Planetary System HAT-P-25

    Science.gov (United States)

    Wang, Xian-Yu; Wang, Songhu; Hinse, Tobias C.; Li, Kai; Wang, Yong-Hao; Laughlin, Gregory; Liu, Hui-Gen; Zhang, Hui; Wu, Zhen-Yu; Zhou, Xu; Zhou, Ji-Lin; Hu, Shao-Ming; Wu, Dong-Hong; Peng, Xi-Yan; Chen, Yuan-Yuan

    2018-06-01

    We present eight new light curves of the transiting extra-solar planet HAT-P-25b obtained from 2013 to 2016 with three telescopes at two observatories. We use the new light curves, along with recent literature material, to estimate the physical and orbital parameters of the transiting planet. Specifically, we determine the mid-transit times (T C ) and update the linear ephemeris, T C[0] = 2456418.80996 ± 0.00025 [BJDTDB] and P = 3.65281572 ± 0.00000095 days. We carry out a search for transit timing variations (TTVs), and find no significant TTV signal at the ΔT = 80 s-level, placing a limit on the possible strength of planet–planet interactions (TTVG). In the course of our analysis, we calculate the upper mass-limits of the potential nearby perturbers. Near the 1:2, 2:1, and 3:1 resonances with HAT-P-25b, perturbers with masses greater than 0.5, 0.3, and 0.5 M ⊕ respectively, can be excluded. Furthermore, based on the analysis of TTVs caused by light travel time effect (LTTE) we also eliminate the possibility that a long-period perturber exists with M p > 3000 MJ within a = 11.2 au of the parent star.

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

    Science.gov (United States)

    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.

  9. A Novel Reliability Enhanced Handoff Method in Future Wireless Heterogeneous Networks

    Directory of Open Access Journals (Sweden)

    Wang YuPeng

    2016-01-01

    Full Text Available As the demand increases, future networks will follow the trends of network variety and service flexibility, which requires heterogeneous type of network deployment and reliable communication method. In practice, most communication failure happens due to the bad radio link quality, i.e., high-speed users suffers a lot on the problem of radio link failure, which causes the problem of communication interrupt and radio link recovery. To make the communication more reliable, especially for the high mobility users, we propose a novel communication handoff mechanism to reduce the occurrence of service interrupt. Based on computer simulation, we find that the reliability on the service is greatly improved.

  10. First-time viewers' comprehension of films: bridging shot transitions.

    Science.gov (United States)

    Ildirar, Sermin; Schwan, Stephan

    2015-02-01

    Which perceptual and cognitive prerequisites must be met in order to be able to comprehend a film is still unresolved and a controversial issue. In order to gain some insights into this issue, our field experiment investigates how first-time adult viewers extract and integrate meaningful information across film cuts. Three major types of commonalities between adjacent shots were differentiated, which may help first-time viewers with bridging the shots: pictorial, causal, and conceptual. Twenty first-time, 20 low-experienced and 20 high-experienced viewers from Turkey were shown a set of short film clips containing these three kinds of commonalities. Film clips conformed also to the principles of continuity editing. Analyses of viewers' spontaneous interpretations show that first-time viewers indeed are able to notice basic pictorial (object identity), causal (chains of activity), as well as conceptual (links between gaze direction and object attention) commonalities between shots due to their close relationship with everyday perception and cognition. However, first-time viewers' comprehension of the commonalities is to a large degree fragile, indicating the lack of a basic notion of what constitutes a film. © 2014 The British Psychological Society.

  11. Relationship between transit time and mechanical properties of a cell through a stenosed microchannel.

    Science.gov (United States)

    Ye, Ting; Shi, Huixin; Phan-Thien, Nhan; Lim, Chwee Teck; Li, Yu

    2018-01-24

    The changes in the mechanical properties of a cell are not only the cause of some diseases, but can also be a biomarker for some disease states. In recent times, microfluidic devices with built-in constrictions have been widely used to measure these changes. The transit time in such devices, defined as the time that a cell takes to pass through a constriction, has been found to be a crucial factor associated with the cell mechanical properties. Here, we use smoothed dissipative particle dynamics (SDPD), a particle-based numerical method, to explore the relationship between the transit time and mechanical properties of a cell. Three expressions of the transit time are developed from our simulation data, with respect to the stenosed size of constrictions, the shear modulus and bending modulus of cells, respectively. We show that a convergent constriction (the inlet is wider than the outlet), and a sharp-corner constriction (the constriction outlet is narrow) are better in identifying the differences in the transit time of cells. Moreover, the transit time increases and gradually approaches a constant as the shear modulus of cells increases, but increases first and then decreases as the bending modulus increases. These results suggest that the mechanical properties of cells can indeed be measured by analyzing their transit time, based on the recommended microfluidic device.

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

    Science.gov (United States)

    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

  13. Takeover Time in Highly Automated Vehicles: Noncritical Transitions to and From Manual Control.

    Science.gov (United States)

    Eriksson, Alexander; Stanton, Neville A

    2017-06-01

    The aim of this study was to review existing research into driver control transitions and to determine the time it takes drivers to resume control from a highly automated vehicle in noncritical scenarios. Contemporary research has moved from an inclusive design approach to adhering only to mean/median values when designing control transitions in automated driving. Research into control transitions in highly automated driving has focused on urgent scenarios where drivers are given a relatively short time span to respond to a request to resume manual control. We found a paucity in research into more frequent scenarios for control transitions, such as planned exits from highway systems. Twenty-six drivers drove two scenarios with an automated driving feature activated. Drivers were asked to read a newspaper, or to monitor the system, and to relinquish, or resume, control from the automation when prompted by vehicle systems. Significantly longer control transition times were found between driving with and without secondary tasks. Control transition times were substantially longer than those reported in the peer-reviewed literature. We found that drivers take longer to resume control when under no time pressure compared with that reported in the literature. Moreover, we found that drivers occupied by a secondary task exhibit larger variance and slower responses to requests to resume control. Workload scores implied optimal workload. Intra- and interindividual differences need to be accommodated by vehicle manufacturers and policy makers alike to ensure inclusive design of contemporary systems and safety during control transitions.

  14. Postfoundational practical theology for a time of transition

    African Journals Online (AJOL)

    Test

    2010-09-01

    Sep 1, 2010 ... Since 1990, I was involved in full time teaching and my focus was on pastoral narrative therapy. .... a balance between 'the way our beliefs are anchored in .... But couldn't we ourselves, each one of us, make our life a work.

  15. Out-of-equilibrium dynamics driven by localized time-dependent perturbations at quantum phase transitions

    Science.gov (United States)

    Pelissetto, Andrea; Rossini, Davide; Vicari, Ettore

    2018-03-01

    We investigate the quantum dynamics of many-body systems subject to local (i.e., restricted to a limited space region) time-dependent perturbations. If the system crosses a quantum phase transition, an off-equilibrium behavior is observed, even for a very slow driving. We show that, close to the transition, time-dependent quantities obey scaling laws. In first-order transitions, the scaling behavior is universal, and some scaling functions can be computed exactly. For continuous transitions, the scaling laws are controlled by the standard critical exponents and by the renormalization-group dimension of the perturbation at the transition. Our protocol can be implemented in existing relatively small quantum simulators, paving the way for a quantitative probe of the universal off-equilibrium scaling behavior, without the need to manipulate systems close to the thermodynamic limit.

  16. Computation of transit times using the milestoning method with applications to polymer translocation

    Science.gov (United States)

    Hawk, Alexander T.; Konda, Sai Sriharsha M.; Makarov, Dmitrii E.

    2013-08-01

    Milestoning is an efficient approximation for computing long-time kinetics and thermodynamics of large molecular systems, which are inaccessible to brute-force molecular dynamics simulations. A common use of milestoning is to compute the mean first passage time (MFPT) for a conformational transition of interest. However, the MFPT is not always the experimentally observed timescale. In particular, the duration of the transition path, or the mean transit time, can be measured in single-molecule experiments, such as studies of polymers translocating through pores and fluorescence resonance energy transfer studies of protein folding. Here we show how to use milestoning to compute transit times and illustrate our approach by applying it to the translocation of a polymer through a narrow pore.

  17. Characterisation of cerebral blood flow via determining the vascular mean transit time

    International Nuclear Information System (INIS)

    Lindner, P.; Thelen, M.

    1987-01-01

    By using a recently developed algorithm it is possible to quantify the dynamic information of a DSA sequence of the brain. The theory of algorithm allows to calculate vascular mean transit from time density curves. The algorithm minimizes the problems of densitometry with regard to 'quantitative DSA'. There is a strong correlation between vascular mean transit times and cerebral blood flow values, and therefore the results for mean transit times also correspond to the results obtained for cerebral blood flow. By computerized postprocessing of DSA-images it is possible to generate functional images of the brain with a spatial resolution that had not been attainable so far. The images represent the distribution pattern of reverse vascular mean transit times. The results from 36 patients with proven stenoses of the cervical vessels are reported. (orig.) [de

  18. Calculation model for 16N transit time in the secondary side of steam generators

    International Nuclear Information System (INIS)

    Liu Songyu; Xu Jijun; Xu Ming

    1998-01-01

    The 16 N transit time is essential to determine the leak-rate of steam generator tubes leaks with 16 N monitoring system, which is a new technique. A model was developed for calculation 16 N transit time in the secondary side of steam generators. According to the flow characters of secondary side fluid, the transit times divide into four sectors from tube sheet to the sensor on steam line. The model assumes that 16 N is moving as vapor phase in the secondary-side. So the model for vapor velocity distribution in tube bundle is presented in detail. The 16 N transit time calculation results of this model compare with these of EDF on steam generator of Qinshan NPP

  19. The transition time induced narrow linewidth of the electromagnetically induced transparency in caesium vapour

    International Nuclear Information System (INIS)

    Li Luming; Peng Xiang; Liu Cheng; Guo Hong; Chen Xuzong

    2004-01-01

    We observed a narrow linewidth (∼60 kHz) in a Doppler-broadened system showing electromagnetically induced transparency in caesium atomic vapour. The transition time induced reduction of the linewidth is illustrated both theoretically and experimentally

  20. Connecting People to Places : Spatiotemporal Analysis of Transit Supply Using Travel Time Cubes

    Science.gov (United States)

    2016-06-01

    Despite its importance, temporal measures of accessibility are rarely used in transit research or practice. This is primarily due to the inherent difficulty and complexity in computing time-based accessibility metrics. Estimating origin-to-destinatio...

  1. Using Dielectric Relaxation Spectroscopy to Characterize the Glass Transition Time of Polydextrose.

    Science.gov (United States)

    Buehler, Martin G; Kindle, Michael L; Carter, Brady P

    2015-06-01

    Dielectric relaxation spectroscopy was used to characterize the glass transition time, tg , of polydextrose, where the glass transition temperature, Tg , and water activity, aw (relative humidity), were held constant during polydextrose relaxation. The tg was determined from a shift in the peak frequency of the imaginary capacitance spectrum with time. It was found that when the peak frequency reaches 30 mHz, polydextrose undergoes glass transition. Glass transition time, tg , is the time for polydextrose to undergo glass transition at a specific Tg and aw . Results lead to a modified state diagram, where Tg is depressed with increasing aw . This curve forms a boundary: (a) below the boundary, polydextrose does not undergo glass transition and (b) above the boundary, polydextrose rapidly undergoes glass transition. As the boundary curve is specified by a tg value, it can assist in the selection of storage conditions. An important point on the boundary curve is at aw = 0, where Tg0 = 115 °C. The methodology can also be used to calculate the stress-relaxation viscosity of polydextrose as a function of Tg and aw , which is important when characterizing the flow properties of polydextrose initially in powder form. © 2015 Institute of Food Technologists®

  2. Relations between transit time, fermentation products, and hydrogen consuming flora in healthy humans.

    OpenAIRE

    El Oufir, L; Flourié, B; Bruley des Varannes, S; Barry, J L; Cloarec, D; Bornet, F; Galmiche, J P

    1996-01-01

    BACKGROUND/AIMS: To investigate whether transit time could influence H2 consuming flora and certain indices of colonic bacterial fermentation. METHODS: Eight healthy volunteers (four methane excretors and four non-methane excretors) were studied for three, three week periods during which they received a controlled diet alone (control period), and then the same diet with cisapride or loperamide. At the end of each period, mean transit time (MTT) was estimated, an H2 lactulose breath test was p...

  3. Transit timing observations from Kepler. VI. Potentially interesting candidate systems from fourier-based statistical tests

    DEFF Research Database (Denmark)

    Steffen, J.H.; Ford, E.B.; Rowe, J.F.

    2012-01-01

    We analyze the deviations of transit times from a linear ephemeris for the Kepler Objects of Interest (KOI) through quarter six of science data. We conduct two statistical tests for all KOIs and a related statistical test for all pairs of KOIs in multi-transiting systems. These tests identify...... several systems which show potentially interesting transit timing variations (TTVs). Strong TTV systems have been valuable for the confirmation of planets and their mass measurements. Many of the systems identified in this study should prove fruitful for detailed TTV studies....

  4. TRANSIT TIMING OBSERVATIONS FROM KEPLER. VI. POTENTIALLY INTERESTING CANDIDATE SYSTEMS FROM FOURIER-BASED STATISTICAL TESTS

    International Nuclear Information System (INIS)

    Steffen, Jason H.; Ford, Eric B.; Rowe, Jason F.; Borucki, William J.; Bryson, Steve; Caldwell, Douglas A.; Jenkins, Jon M.; Koch, David G.; Sanderfer, Dwight T.; Seader, Shawn; Twicken, Joseph D.; Fabrycky, Daniel C.; Holman, Matthew J.; Welsh, William F.; Batalha, Natalie M.; Ciardi, David R.; Kjeldsen, Hans; Prša, Andrej

    2012-01-01

    We analyze the deviations of transit times from a linear ephemeris for the Kepler Objects of Interest (KOI) through quarter six of science data. We conduct two statistical tests for all KOIs and a related statistical test for all pairs of KOIs in multi-transiting systems. These tests identify several systems which show potentially interesting transit timing variations (TTVs). Strong TTV systems have been valuable for the confirmation of planets and their mass measurements. Many of the systems identified in this study should prove fruitful for detailed TTV studies.

  5. Transiting Exoplanet Monitoring Project (TEMP). II. Refined System Parameters and Transit Timing Analysis of HAT-P-33b

    Science.gov (United States)

    Wang, Yong-Hao; Wang, Songhu; Liu, Hui-Gen; Hinse, Tobias C.; Laughlin, Gregory; Wu, Dong-Hong; Zhang, Xiaojia; Zhou, Xu; Wu, Zhenyu; Zhou, Ji-Lin; Wittenmyer, R. A.; Eastman, Jason; Zhang, Hui; Hori, Yasunori; Narita, Norio; Chen, Yuanyuan; Ma, Jun; Peng, Xiyan; Zhang, Tian-Meng; Zou, Hu; Nie, Jun-Dan; Zhou, Zhi-Min

    2017-08-01

    We present 10 R-band photometric observations of eight different transits of the hot Jupiter HAT-P-33b, which has been targeted by our Transiting Exoplanet Monitoring Project. The data were obtained by two telescopes at the Xinglong Station of National Astronomical Observatories of China (NAOC) from 2013 December through 2016 January, and exhibit photometric scatter of 1.6{--}3.0 {mmag}. After jointly analyzing the previously published photometric data, radial-velocity (RV) measurements, and our new light curves, we revisit the system parameters and orbital ephemeris for the HAT-P-33b system. Our results are consistent with the published values except for the planet to star radius ratio ({R}{{P}}/{R}* ), the ingress/egress duration (τ) and the total duration (T 14), which together indicate a slightly shallower and shorter transit shape. Our results are based on more complete light curves, whereas the previously published work had only one complete transit light curve. No significant anomalies in Transit Timing Variations (TTVs) are found, and we place upper mass limits on potential perturbers, largely supplanting the loose constraints provided by the extant RV data. The TTV limits are stronger near mean-motion resonances, especially for the low-order commensurabilities. We can exclude the existence of a perturber with mass larger than 0.6, 0.3, 0.5, 0.5, and 0.3 {M}\\oplus near the 1:3, 1:2, 2:3, 3:2, and 2:1 resonances, respectively.

  6. Scintigraphic Small Intestinal Transit Time and Defaecography in Patients with J-Pouch

    Directory of Open Access Journals (Sweden)

    Mie Dilling Kjaer

    2015-10-01

    Full Text Available Objective methods for examination of pouch function are warranted for a better understanding of the functional result and treatment of dysfunction. The objective of this study was to evaluate the results of scintigraphic intestinal transit time and defaecography compared to the results of pouch function, mucosal condition and a questionnaire on quality of life (QoL. This cross-sectional study included 21 patients. Scintigraphic transit time and defaecography was determined with the use of Tc-99m. Pouch function was assessed by number of bowel movements, pouch volume, and continence. Pouch mucosal condition was evaluated by endoscopy and histology. Median transit time was 189 min (105–365. Median ejection fraction at defaecography (EF was 49% (3–77 and 62% (17–98 after first and second defecation. Median pouch volume was 223 mL (100–360. A median daily stool frequency of nine (4–25 was reported and three (14% patients suffered from daytime incontinence. No patients had symptomatic or endoscopic pouchitis; however, the histology showed unspecific inflammation in 19 (90% patients. There was no correlation between transit time, evacuation fraction (EF and pouch function in univariate analysis. However, we found a high body mass index (BMI and a low bowel movement frequency to be associated with a longer transit time by multivariate analysis. Scintigraphic determination of transit time and defaecography are feasible methods in patients with ileal pouch anal anastomosis, but the clinical relevance is yet doubtful.

  7. Proof of Concept: Design and Initial Evaluation of a Device to Measure Gastrointestinal Transit Time.

    Science.gov (United States)

    Wagner, Robert H; Savir-Baruch, Bital; Halama, James R; Venu, Mukund; Gabriel, Medhat S; Bova, Davide

    2017-09-01

    Chronic constipation and gastrointestinal motility disorders constitute a large part of a gastroenterology practice and have a significant impact on a patient's quality of life and lifestyle. In most cases, medications are prescribed to alleviate symptoms without there being an objective measurement of response. Commonly used investigations of gastrointestinal transit times are currently limited to radiopaque markers or electronic capsules. Repeated use of these techniques is limited because of the radiation exposure and the significant cost of the devices. We present the proof of concept for a new device to measure gastrointestinal transit time using commonly available and inexpensive materials with only a small amount of radiotracer. Methods: We assembled gelatin capsules containing a 67 Ga-citrate-radiolabeled grain of rice embedded in paraffin for use as a point-source transit device. It was tested for stability in vitro and subsequently was given orally to 4 healthy volunteers and 10 patients with constipation or diarrhea. Imaging was performed at regular intervals until the device was excreted. Results: The device remained intact and visible as a point source in all subjects until excretion. When used along with a diary of bowel movement times and dates, the device could determine the total transit time. The device could be visualized either alone or in combination with a barium small-bowel follow-through study or a gastric emptying study. Conclusion: The use of a point-source transit device for the determination of gastrointestinal transit time is a feasible alternative to other methods. The device is inexpensive and easy to assemble, requires only a small amount of radiotracer, and remains inert throughout the gastrointestinal tract, allowing for accurate determination of gastrointestinal transit time. Further investigation of the device is required to establish optimum imaging parameters and reference values. Measurements of gastrointestinal transit time

  8. The role of nuclear energy in times of energy transition

    International Nuclear Information System (INIS)

    2012-01-01

    Since the reactor catastrophe in Fukushima, the risk of nuclear power has once again become more evident to the public and has also led to a rethinking of politics in Europe. Slogans like ''Nuclear Power, No Thanks!'', ''Get Out of Euratom'' are making more and more the rounds. The phase-out of nuclear energy is the topic that is increasingly provoking people to think. But how should one handle this? What role will nuclear energy play in a distant future? Central factors such as the economic viability of renewable energy sources and the environmental and social compatibility of production and distribution must be taken into account, while at the same time the reduction of pollutants and greenhouse gases must continue. If this is done without nuclear energy, is the rapid abandonment of nuclear energy even necessary or does nuclear energy generation have to be used as a temporary solution? (roessner)

  9. TRANSIT

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. TRANSIT. SYSTEM: DETERMINE 2D-POSITION GLOBALLY BUT INTERMITTENT (POST-FACTO). IMPROVED ACCURACY. PRINCIPLE: POLAR SATELLITES WITH INNOVATIONS OF: GRAVITY-GRADIENT ATTITUDE CONTROL; DRAG COMPENSATION. WORKS ...

  10. [Determination of total and segmental colonic transit time in constipated children].

    Science.gov (United States)

    Zhang, Shu-cheng; Wang, Wei-lin; Bai, Yu-zuo; Yuan, Zheng-wei; Wang, Wei

    2003-03-01

    To determine the total and segmental colonic transit time of normal Chinese children and to explore its value in constipation in children. The subjects involved in this study were divided into 2 groups. One group was control, which had 33 healthy children (21 males and 12 females) aged 2 - 13 years (mean 5 years). The other was constipation group, which had 25 patients (15 males and 10 females) aged 3 - 14 years (mean 7 years) with constipation according to Benninga's criteria. Written informed consent was obtained from the parents of each subject. In this study the simplified method of radio opaque markers was used to determine the total gastrointestinal transit time and segmental colonic transit time of the normal and constipated children, and in part of these patients X-ray defecography was also used. The total gastrointestinal transit time (TGITT), right colonic transit time (RCTT), left colonic transit time (LCTT) and rectosigmoid colonic transit time (RSTT) of the normal children were 28.7 +/- 7.7 h, 7.5 +/- 3.2 h, 6.5 +/- 3.8 h and 13.4 +/- 5.6 h, respectively. In the constipated children, the TGITT, LCTT and RSTT were significantly longer than those in controls (92.2 +/- 55.5 h vs 28.7 +/- 7.7 h, P < 0.001; 16.9 +/- 12.6 h vs 6.5 +/- 3.8 h, P < 0.01; 61.5 +/- 29.0 h vs 13.4 +/- 5.6 h, P < 0.001), while the RCTT had no significant difference. X-ray defecography demonstrated one rectocele, one perineal descent syndrome and one puborectal muscle syndrome, respectively. The TGITT, RCTT, LCTT and RSTT of the normal children were 28.7 +/- 7.7 h, 7.5 +/- 3.2 h, 6.5 +/- 3.8 h and 13.4 +/- 5.6 h, respectively. With the segmental colonic transit time, constipation can be divided into four types: slow-transit constipation, outlet obstruction, mixed type and normal transit constipation. X-ray defecography can demonstrate the anatomical or dynamic abnormalities within the anorectal area, with which constipation can be further divided into different subtypes, and

  11. Firing patterns transition and desynchronization induced by time delay in neural networks

    Science.gov (United States)

    Huang, Shoufang; Zhang, Jiqian; Wang, Maosheng; Hu, Chin-Kun

    2018-06-01

    We used the Hindmarsh-Rose (HR) model (Hindmarsh and Rose, 1984) to study the effect of time delay on the transition of firing behaviors and desynchronization in neural networks. As time delay is increased, neural networks exhibit diversity of firing behaviors, including regular spiking or bursting and firing patterns transitions (FPTs). Meanwhile, the desynchronization of firing and unstable bursting with decreasing amplitude in neural system, are also increasingly enhanced with the increase of time delay. Furthermore, we also studied the effect of coupling strength and network randomness on these phenomena. Our results imply that time delays can induce transition and desynchronization of firing behaviors in neural networks. These findings provide new insight into the role of time delay in the firing activities of neural networks, and can help to better understand the firing phenomena in complex systems of neural networks. A possible mechanism in brain that can cause the increase of time delay is discussed.

  12. Daylight saving time transitions and hospital treatments due to accidents or manic episodes

    Directory of Open Access Journals (Sweden)

    Lönnqvist Jouko

    2008-02-01

    Full Text Available Abstract Background Daylight saving time affects millions of people annually but its impacts are still widely unknown. Sleep deprivation and the change of circadian rhythm can trigger mental illness and cause higher accident rates. Transitions into and out of daylight saving time changes the circadian rhythm and may cause sleep deprivation. Thus it seems plausible that the prevalence of accidents and/or manic episodes may be higher after transition into and out of daylight saving time. The aim of this study was to explore the effects of transitions into and out of daylight saving time on the incidence of accidents and manic episodes in the Finnish population during the years of 1987 to 2003. Methods The nationwide data were derived from the Finnish Hospital Discharge Register. From the register we obtained the information about the hospital-treated accidents and manic episodes during two weeks before and two weeks after the transitions in 1987–2003. Results The results were negative, as the transitions into or out of daylight saving time had no significant effect on the incidence of accidents or manic episodes. Conclusion One-hour transitions do not increase the incidence of manic episodes or accidents which require hospital treatment.

  13. Daylight saving time transitions and hospital treatments due to accidents or manic episodes

    Science.gov (United States)

    Lahti, Tuuli A; Haukka, Jari; Lönnqvist, Jouko; Partonen, Timo

    2008-01-01

    Background Daylight saving time affects millions of people annually but its impacts are still widely unknown. Sleep deprivation and the change of circadian rhythm can trigger mental illness and cause higher accident rates. Transitions into and out of daylight saving time changes the circadian rhythm and may cause sleep deprivation. Thus it seems plausible that the prevalence of accidents and/or manic episodes may be higher after transition into and out of daylight saving time. The aim of this study was to explore the effects of transitions into and out of daylight saving time on the incidence of accidents and manic episodes in the Finnish population during the years of 1987 to 2003. Methods The nationwide data were derived from the Finnish Hospital Discharge Register. From the register we obtained the information about the hospital-treated accidents and manic episodes during two weeks before and two weeks after the transitions in 1987–2003. Results The results were negative, as the transitions into or out of daylight saving time had no significant effect on the incidence of accidents or manic episodes. Conclusion One-hour transitions do not increase the incidence of manic episodes or accidents which require hospital treatment. PMID:18302734

  14. Critical Time Intervention for Homeless People Making the Transition to Community Living: A Randomized Controlled Trial

    NARCIS (Netherlands)

    Vet, R. de; Beijersbergen, M.D.; Jonker, I.E.; Lako, D.A.M.; Hemert, A.M. van; Herman, D.B.; Wolf, J.R.L.M.

    2017-01-01

    To help create an evidence base in Europe for effective interventions that improve the well-being of homeless people, we tested whether critical time intervention (CTI), a time-limited intervention developed to support vulnerable people during times of transition, is effective outside the United

  15. On the fast estimation of transit times application to BWR simulated data

    International Nuclear Information System (INIS)

    Antonopoulos-Domis, M.; Marseguerra, M.; Padovani, E.

    1996-01-01

    Real time estimators of transit times are proposed. BWR noise is simulated including a global component due to rod vibration. The time obtained form the simulation is used to investigate the robustness and noise immunity of the estimators. It is found that, in presence of a coincident (global) signal, the cross-correlation function is the worst estimator. (authors)

  16. Gastrointestinal Transit Time, Glucose Homeostasis and Metabolic Health: Modulation by Dietary Fibers.

    Science.gov (United States)

    Müller, Mattea; Canfora, Emanuel E; Blaak, Ellen E

    2018-02-28

    Gastrointestinal transit time may be an important determinant of glucose homeostasis and metabolic health through effects on nutrient absorption and microbial composition, among other mechanisms. Modulation of gastrointestinal transit may be one of the mechanisms underlying the beneficial health effects of dietary fibers. These effects include improved glucose homeostasis and a reduced risk of developing metabolic diseases such as obesity and type 2 diabetes mellitus. In this review, we first discuss the regulation of gastric emptying rate, small intestinal transit and colonic transit as well as their relation to glucose homeostasis and metabolic health. Subsequently, we briefly address the reported health effects of different dietary fibers and discuss to what extent the fiber-induced health benefits may be mediated through modulation of gastrointestinal transit.

  17. The Handover Project: Improving the continuity of patient care through identification and implementation of novel patient handoff processes in Europe

    NARCIS (Netherlands)

    Drachsler, Hendrik; Kicken, Wendy; Van der Klink, Marcel; Stoyanov, Slavi; Boshuizen, Els

    2011-01-01

    Drachsler, H., Kicken, W., Van der Klink, M., Stoyanov, S., & Boshuizen, H. P. A. (2011, 21 March). The Handover project: Improving the continuity of patient care through identification and implementation of novel patient handoff processes in Europe. Presentation at Learning Networks meeting,

  18. Finite-time quantum-to-classical transition for a Schroedinger-cat state

    International Nuclear Information System (INIS)

    Paavola, Janika; Hall, Michael J. W.; Paris, Matteo G. A.; Maniscalco, Sabrina

    2011-01-01

    The transition from quantum to classical, in the case of a quantum harmonic oscillator, is typically identified with the transition from a quantum superposition of macroscopically distinguishable states, such as the Schroedinger-cat state, into the corresponding statistical mixture. This transition is commonly characterized by the asymptotic loss of the interference term in the Wigner representation of the cat state. In this paper we show that the quantum-to-classical transition has different dynamical features depending on the measure for nonclassicality used. Measures based on an operatorial definition have well-defined physical meaning and allow a deeper understanding of the quantum-to-classical transition. Our analysis shows that, for most nonclassicality measures, the Schroedinger-cat state becomes classical after a finite time. Moreover, our results challenge the prevailing idea that more macroscopic states are more susceptible to decoherence in the sense that the transition from quantum to classical occurs faster. Since nonclassicality is a prerequisite for entanglement generation our results also bridge the gap between decoherence, which is lost only asymptotically, and entanglement, which may show a ''sudden death''. In fact, whereas the loss of coherences still remains asymptotic, we emphasize that the transition from quantum to classical can indeed occur at a finite time.

  19. Electric dipole transitions for four-times ionized cerium (Ce V)

    Energy Technology Data Exchange (ETDEWEB)

    Usta, Betül Karaçoban, E-mail: bkaracoban@sakarya.edu.tr; Akgün, Elif, E-mail: elif.akgun@ogr.sakarya.edu.tr; Alparslan, Büşra, E-mail: busra.alparslan1@ogr.sakarya.edu.tr [Physics Department, Sakarya University, 54187, Sakarya (Turkey)

    2016-03-25

    We have calculated the transition parameters, such as wavelengths, oscillator strengths, and transition probabilities (or rates), for the electric dipole (E1) transitions in four-times ionized cerium (Ce V, Z = 58) by using the multiconfiguration Hartree-Fock method within the framework of Breit-Pauli (MCHF+BP) relativistic corrections and the relativistic Hartree-Fock (HFR) method. The obtained results have been compared with other works available in literature. A discussion of these calculations for Ce V in this study has also been in view of the MCHF+BP and HFR methods.

  20. Determination of Gastrointestinal Transit Times in Barred Owls ( Strix varia ) by Contrast Fluoroscopy.

    Science.gov (United States)

    Doss, Grayson A; Williams, Jackie M; Mans, Christoph

    2017-06-01

    Contrast imaging studies are routinely performed in avian patients when an underlying abnormality of the gastrointestinal (GI) tract is suspected. Fluoroscopy offers several advantages over traditional radiography and can be performed in conscious animals with minimal stress and restraint. Although birds of prey are commonly encountered as patients, little is known about GI transit times and contrast imaging studies in these species, especially owls. Owls are commonly encountered in zoological, educational, and wildlife settings. In this study, 12 adult barred owls ( Strix varia ) were gavage fed a 30% weight-by-volume barium suspension (25 mL/kg body weight). Fluoroscopic exposures were recorded at 5, 15, 30, 60, 120, 180, 240, and 300 minutes after administration. Overall GI transit time and transit times of various GI organs were recorded. Median (interquartile range [IQR]) overall GI transit time was 60 minutes (IQR: 19-60 minutes) and ranged from 5-120 minutes. Ventricular and small intestinal contrast filling was rapid. Ventricular emptying was complete by a median of 60 minutes (IQR: 30-120 minutes; range: 30-240 minutes), whereas small intestinal emptying was not complete in 9/12 birds by 300 minutes. Median small intestinal contraction rate was 15 per minute (IQR: 13-16 minutes; range: 10-19 minutes). Median overall GI transit time in barred owls is more rapid than mean transit times reported for psittacine birds and red-tailed hawks ( Buteo jamaicensis ). Fluoroscopy is a safe, suitable method for investigating GI motility and transit in this species.

  1. A search for transit timing variations and orbital decay in WASP-46b

    Science.gov (United States)

    Petrucci, R.; Jofré, E.; Ferrero, L. V.; Cúneo, V.; Saker, L.; Lovos, F.; Gómez, M.; Mauas, P.

    2018-02-01

    We present 12 new transit observations of the exoplanet WASP-46b obtained with the 1.54-m telescope at Estación Astrofísica de Bosque Alegre (EABA, Argentina) and the 0.40-m Horacio Ghielmetti and 2.15-m Jorge Sahade telescopes at Complejo Astronómico El Leoncito (CASLEO, Argentina). We analyse them together with 37 light curves from the literature to re-determine the physical parameters and search for additional planets via transit timing variations (TTVs). We consider the 31 transits with uncertainties in their mid-transit times (e_T0) activity could be affecting the measured mid-transit times. This value of dispersion allows us to rule out the presence of additional bodies with masses larger than 2.3, 4.6, 7 and 9.3 M_{\\oplus} at the first-order mean-motion resonances 2:1, 3:2, 4:3 and 5:4 with the transiting planet, respectively. Despite the 6 yr baseline and a typical light-curve precision of 2 × 10-3, we find that we cannot significantly demonstrate a slow decrease of the orbital period of WASP-46b. We place a lower limit of Q⋆ > 7 × 103 on the tidal quality factor and determine that an additional 6 yr baseline is required to rule out Q⋆ < 105.

  2. The determination of allowed outage time using the evaluation of transition risk

    International Nuclear Information System (INIS)

    Kang, D. I.; Kim, K. Y.; Jang, S. C.

    2001-03-01

    he objectives of this study are to propose a new evaluation method for transition risk and to determine the AOT using the new method. We review and compare the evaluation methods of transition risk which was previously studied. We also identify important assumptions used in previous studies for the evaluation of transition risk. We select general items required for the development of evaluation method for the transition risk. Based on the items selected, we propose a new evaluation method for transition risk. The new evaluation method for the transition risk is based on following assumptions; 1)For the same time span, the risk occurred from the failure to the completion of component repair during power operation is the same as the total risk including the risk occurred from power operation to specific shutdown/low power operation and the risk from specific shutdown/low power operation to power operation. 2)Shutdown operation and the repair of components are initiated just after the identification of the failure of components. The evaluation of the transition risk is performed to incorporate the characteristics of shutdown operation into Ulchin Units 3 and 4 Level 1 internal PSA for power operation. The application results of the new method to the HPSIS and the LPSIS for Ulchin Units 3 and 4 show that the AOT of HPSIS is properly determined and the AOT of LPSIS can be greatly increased. In this study, the main factors affecting the determination of AOT using the evaluation for transition risk are identified as the time of shutdown operation, the consideration of the change on common cause failure probability, and the risk of shutdown operation. It is expected that the evaluation method for the transition risk proposed in this study will be used for the determination of AOT and for the decision, in the case of the components unavailable, whether power operation is continuously performed or shutdown operation is initiated

  3. Reactive scattering theory for molecular transitions in time-dependent fields

    International Nuclear Information System (INIS)

    Peskin, U.; Miller, W.H.

    1995-01-01

    A new approach is introduced for computing probabilities of molecular transitions in time-dependent fields. The method is based on the stationary (t,t') representation of the Schroedinger equation and is shown to be equivalent to infinite order time-dependent perturbation theory. Bound-to-bound (i.e., photoexcitation) and bound-to-continuum (i.e., photoreaction) transitions are regarded as reactive collisions with the ''time coordinate'' as the reaction coordinate in an extended Hilbert space. A numerical method based on imposing absorbing boundary conditions for the time coordinate in a discrete variable representation framework is introduced. A single operation of the Green's operator provides all the state-specific transition probabilities as well as partial state-resolved (inclusive) reaction probabilities. Illustrative numerical applications are given for model systems

  4. Dual-phase helical CT using bolus triggering technique: optimization of transition time

    International Nuclear Information System (INIS)

    Choi, Young Ho; Kim, Tae Kyoung; Park, Byung Kwan; Koh, Young Hwan; Han, Joon Koo; Choi, Byung Ihn

    1999-01-01

    To optimize the transition time between the triggering point in monitoring scanning and the initiation of diagnostic hepatic arterial phase (HAP) scanning in hepatic spiral CT, using a bolus triggering technique. One hundred consecutive patients with focal hepatic lesion were included in this study. Patients were randomized into two groups. Transition times of 7 and 11 seconds were used in group 1 and 2, respectively. In all patients, bolus triggered HAP spiral CT was obtained using a semi-automatic bolus tracking program after the injection of 120mL of non-ionic contrast media at a rate of 3mL/sec. When aortic enhancement reached 90 HU, diagnostic HAP scanning began after a given transition time. From images of group 1 and group 2, the degree of parenchymal enhancement of the liver and tumor-to-liver attenuation difference were measured. Also, for qualitative analysis, conspicuity of the hepatic artery and hypervascular tumor was scored and analyzed. Hepatic parenchymal enhancement on HAP was 12.07 + /-6.44 HU in group 1 and 16.03 + /-5.80 HU in group 2 (p .05). In the evaluation of conspicuity of hepatic artery, there was no statistically significant difference between the two groups (p > .05). The conspicuity of hypervascular tumors in group 2 was higher than in group 1 (p < .05). HAP spiral CT using a bolus triggering technique with a transition time of 11 seconds provides better HAP images than when the transition time is 7 seconds

  5. The Ebb and Flow of Filipino First-Time Fatherhood Transition Space: A Grounded Theory Study.

    Science.gov (United States)

    Villamor, Neil Jupiter E; de Guzman, Allan B; Matienzo, Evangeline T

    2016-11-01

    Fatherhood, as a developmental process, is both a human experience and a text that needs to be read. For developing nations like the Philippines, little is known about the process undergone by first-time fathers on their transition to fatherhood, and how nurses can play a significant role in assisting them. This grounded theory study purported to conceptualize the multifaceted process of transition from the lens of Filipino first-time fathers' lived experiences. A total of 20 first-time fathers from Metro Manila, Philippines, were purposively selected to take part in an individual, semistructured, and in-depth interview. The Glaserian (classical) method of analysis was specifically used, and field texts were inductively analyzed using a repertory grid. Member checking and correspondence were done to validate the findings of the study. Six surfacing stages emerged relative to the process of transition. Interestingly, The B.R.I.D.G.E. Theory of First-Time Fatherhood Transition Space describes how these fathers progress from the beholding, reorganizing, inhibiting, delivering, grasping, and embracing phases toward successful transition. This emerged theoretical model can be used in framing health care programs where the needs of fathers during this period are met and addressed. Finally, it can also be used in guiding nurses in their provision of a more empathetic care for first-time fathers. © The Author(s) 2015.

  6. Mobilising female labour market reserves: What promotes women’s transitions from part-time to full-time work?

    OpenAIRE

    Kitterød, Ragni Hege; Rønsen, Marit; Seierstad, Ane

    2011-01-01

    Considering the high female part-time rates in Norway, one may envisage a sizeable additional labour supply if more part-time working women would switch to full time. In view of an ageing population and increased demand for labour in the future, we investigate this issue by studying married and cohabiting women’s transitions from part-time to full-time work based on panel data from 2003-2009. Contrary to evidence from other countries with well-established support for working mo...

  7. Magnet tracking allows assessment of regional gastrointestinal transit times in children.

    Science.gov (United States)

    Hedsund, Caroline; Joensson, Iben Moeller; Gregersen, Tine; Fynne, Lotte; Schlageter, Vincent; Krogh, Klaus

    2013-01-01

    Data on small intestinal transit time in healthy children are lacking, and normal values for gastric emptying and colonic transit time are sparse. Conventional methods, including radiopaque markers, scintigraphy, and PillCam™ involve radiation or require the child to swallow a large pill. The minimally invasive, radiation-free Motility Tracking System-1 (MTS-1) has been introduced for description of gastrointestinal motility in adults. The aim of the study was to evaluate the MTS-1 for assessment of gastrointestinal transit times and motility patterns in healthy children. Twenty-one healthy children (nine girls), median age 10 (range 7-12) years were included. For evaluation with MTS-1, a small magnetic pill was ingested and tracked through the gastrointestinal tract by a matrix of 16 magnetic sensors placed behind a nonmagnetic bed. The children were investigated for 8 hours after swallowing the magnetic pill and again for 4 hours the following morning. After leaving the unit, each child came back after every bowel movement to determine if the pill had been expelled. Nineteen children could swallow the pill. Characteristic contraction patterns were identified for the stomach (three per minute), small intestine (9-11 per minute), and colon (4-5 per minute). Median total gastrointestinal transit time was 37.7 (range 9.5-95.8) hours, median gastric emptying time was 37 (range 2-142) minutes, median small intestinal transit time was 302 (range 164 to >454) minutes, and median colorectal transit time was 38.1 (range 5.6-90.0) hours. MTS-1 allows minimally invasive evaluation of gastrointestinal motility in children. Use of the method is, however, restricted by the nonambulatory setup.

  8. Scintigraphic small intestinal transit time and defaecography in patients with J-pouch

    DEFF Research Database (Denmark)

    Kjær, Mie Dilling; Simonsen, Jane Angel; Hvidsten, Svend

    2015-01-01

    Objective methods for examination of pouch function are warranted for a better understanding of the functional result and treatment of dysfunction. The objective of this study was to evaluate the results of scintigraphic intestinal transit time and defaecography compared to the results of pouch...... function, mucosal condition and a questionnaire on quality of life (QoL). This cross-sectional study included 21 patients. Scintigraphic transit time and defaecography was determined with the use of Tc-99m. Pouch function was assessed by number of bowel movements, pouch volume, and continence. Pouch...... mucosal condition was evaluated by endoscopy and histology. Median transit time was 189 min (105–365). Median ejection fraction at defaecography (EF) was 49% (3–77) and 62% (17–98) after first and second defecation. Median pouch volume was 223 mL (100–360). A median daily stool frequency of nine (4...

  9. Biomagnetic techniques for evaluating gastric emptying, peristaltic contraction and transit time.

    Science.gov (United States)

    la Roca-Chiapas, Jose María De; Cordova-Fraga, Teodoro

    2011-10-15

    Biomagnetic techniques were used to measure motility in various parts of the gastrointestinal (GI) tract, particularly a new technique for detecting magnetic markers and tracers. A coil was used to enhance the signal from a magnetic tracer in the GI tract and the signal was detected using a fluxgate magnetometer or a magnetoresistor in an unshielded room. Estimates of esophageal transit time were affected by the position of the subject. The reproducibility of estimates derived using the new biomagnetic technique was greater than 85% and it yielded estimates similar to those obtained using scintigraphy. This technique is suitable for studying the effect of emotional state on GI physiology and for measuring GI transit time. The biomagnetic technique can be used to evaluate digesta transit time in the esophagus, stomach and colon, peristaltic frequency and gastric emptying and is easy to use in the hospital setting.

  10. Theoretical determination of transit time locus curves for ultrasonic pulse echo testing - ALOK. Pt. 4

    International Nuclear Information System (INIS)

    Grohs, B.

    1983-01-01

    The ALOK-technique allows the simultaneous detection of flaws and their evaluation with respect to type, location and dimension by interpretation of the transit time behaviour during scanning of the reflector. The accuracy of information obtained by means of this technique can be further improved both during interference elimination and reconstruction owing to the ability of exact calculation of possible transit time locus curves of given reflectors. The mathematical solution of transit time locus curve calculations refers here to pulse echo testing in consideration of the refraction of sound on the forward wedge/test object - interface. The method of solving the problem is equivalent to the Fermat's principle in optics. (orig.) [de

  11. The Transit-Time Distribution from the Northern Hemisphere Midlatitude Surface

    Science.gov (United States)

    Orbe, Clara; Waugh, Darryn W.; Newman, Paul A.; Strahan, Susan; Steenrod, Stephen

    2015-01-01

    The distribution of transit times from the Northern Hemisphere (NH) midlatitude surface is a fundamental property of tropospheric transport. Here we present an analysis of the transit time distribution (TTD) since air last contacted the northern midlatitude surface layer, as simulated by the NASA Global Modeling Initiative Chemistry Transport Model. We find that throughout the troposphere the TTD is characterized by long flat tails that reflect the recirculation of old air from the Southern Hemisphere and results in mean ages that are significantly larger than the modal age. Key aspects of the TTD -- its mode, mean and spectral width -- are interpreted in terms of tropospheric dynamics, including seasonal shifts in the location and strength of tropical convection and variations in quasi-isentropic transport out of the northern midlatitude surface layer. Our results indicate that current diagnostics of tropospheric transport are insufficient for comparing model transport and that the full distribution of transit times is a more appropriate constraint.

  12. Physical activity during video capsule endoscopy correlates with shorter bowel transit time.

    Science.gov (United States)

    Stanich, Peter P; Peck, Joshua; Murphy, Christopher; Porter, Kyle M; Meyer, Marty M

    2017-09-01

     Video capsule endoscopy (VCE) is limited by reliance on bowel motility for propulsion, and lack of physical activity has been proposed as a cause of incomplete studies. Our aim was to prospectively investigate the association between physical activity and VCE bowel transit.  Ambulatory outpatients receiving VCE were eligible for the study. A pedometer was attached at the time of VCE ingestion and step count was recorded at the end of the procedure. VCE completion was assessed by logistic regression models, which included step count (500 steps as one unit). Total transit time was analyzed by Cox proportional hazards models. The hazard ratios (HR) with 95 % confidence interval (CI) indicated the "hazard" of completion, such that HRs > 1 indicated a reduced transit time.  A total of 100 patients were included. VCE was completed in 93 patients (93 %). The median step count was 2782 steps. Step count was not significantly associated with VCE completion (odds ratio 1.45, 95 %CI 0.84, 2.49). Pedometer step count was significantly associated with shorter total, gastric, and small-bowel transit times (HR 1.09, 95 %CI 1.03, 1.16; HR 1.05, 95 %CI 1.00, 1.11; HR 1.07, 95 %CI 1.01, 1.14, respectively). Higher body mass index (BMI) was significantly associated with VCE completion (HR 1.87, 95 %CI 1.18, 2.97) and shorter bowel transit times (HR 1.05, 95 %CI 1.02, 1.08).  Increased physical activity during outpatient VCE was associated with shorter bowel transit times but not with study completion. In addition, BMI was a previously unreported clinical characteristic associated with VCE completion and should be included as a variable of interest in future studies.

  13. Pulmonary blood volume and transit time in cirrhosis: relation to lung function

    DEFF Research Database (Denmark)

    Møller, Søren; Burchardt, H; Øgard, CG

    2006-01-01

    BACKGROUND/AIMS: In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has...... not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls. METHODS: Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis......, in the controls, Pvolume...

  14. Assessment of Tandem Measurements of pH and Total Gut Transit Time in Healthy Volunteers

    OpenAIRE

    Mikolajczyk, Adam E; Watson, Sydeaka; Surma, Bonnie L; Rubin, David T

    2015-01-01

    Objectives: The variation of luminal pH and transit time in an individual is unknown, yet is necessary to interpret single measurements. This study aimed to assess the intrasubject variability of gut pH and transit time in healthy volunteers using SmartPill devices (Covidien, Minneapolis, MN). Methods: Each subject (n=10) ingested two SmartPill devices separated by 24?h. Mean pH values were calculated for 30?min after gastric emptying (AGE), before the ileocecal (BIC) valve, after the ileocec...

  15. Design of handoff procedures for broadband wireless access IEEE 802.16 based networks

    Directory of Open Access Journals (Sweden)

    V. Rangel–Licea

    2008-01-01

    Full Text Available IEEE 802.16 is a protocol for fixed broad band wire less access that is currently trying to add mobility among mobile users in the standard. However, mobility adds some technical barriers that should be solved first, this is the case of HO "handoff" (change of connection between two base stations "BS" by a mobile user. In this paper, the problem of HO in IEEE 802.16 is approached try ing to maintain the quality of service (QoS of mobile users. A mechanism for changing connection during HO is pre sented. A simulation model based on OPNET MODELER1 was developed to evaluate the performance of the proposed HO mechanism. Finally, this paper demonstrates that it is possible to implement a seam less HO mech a nism over IEEE 802.16 even for users with de manding applications such as voice over IP.

  16. Performance analysis of a handoff scheme for two-tier cellular CDMA networks

    Directory of Open Access Journals (Sweden)

    Ahmed Hamad

    2011-07-01

    Full Text Available A two-tier model is used in cellular networks to improve the Quality of Service (QoS, namely to reduce the blocking probability of new calls and the forced termination probability of ongoing calls. One tier, the microcells, is used for slow or stationary users, and the other, the macrocell, is used for high speed users. In Code-Division Multiple-Access (CDMA cellular systems, soft handoffs are supported, which provides ways for further QoS improvement. In this paper, we introduce such a way; namely, a channel borrowing scheme used in conjunction with a First-In-First-Out (FIFO queue in the macrocell tier. A multidimensional Markov chain to model the resulting system is established, and an iterative technique to find the steady-state probability distribution is utilized. This distribution is then used to find the performance measures of interest: new call blocking probability, and forced termination probability.

  17. The Time Course of the Probability of Transition Into and Out of REM Sleep

    Science.gov (United States)

    Bassi, Alejandro; Vivaldi, Ennio A.; Ocampo-Garcés, Adrián

    2009-01-01

    Study Objectives: A model of rapid eye movement (REM) sleep expression is proposed that assumes underlying regulatory mechanisms operating as inhomogenous Poisson processes, the overt results of which are the transitions into and out of REM sleep. Design: Based on spontaneously occurring REM sleep episodes (“Episode”) and intervals without REM sleep (“Interval”), 3 variables are defined and evaluated over discrete 15-second epochs using a nonlinear logistic regression method: “Propensity” is the instantaneous rate of into-REM transition occurrence throughout an Interval, “Volatility” is the instantaneous rate of out-of-REM transition occurrence throughout an Episode, and “Opportunity” is the probability of being in non-REM (NREM) sleep at a given time throughout an Interval, a requisite for transition. Setting: 12:12 light:dark cycle, isolated boxes. Participants: Sixteen male Sprague-Dawley rats Interventions: None. Spontaneous sleep cycles. Measurements and Results: The highest levels of volatility and propensity occur, respectively, at the very beginning of Episodes and Intervals. The new condition stabilizes rapidly, and variables reach nadirs at minute 1.25 and 2.50, respectively. Afterward, volatility increases markedly, reaching values close to the initial level. Propensity increases moderately, the increment being stronger through NREM sleep bouts occurring at the end of long Intervals. Short-term homeostasis is evidenced by longer REM sleep episodes lowering propensity in the following Interval. Conclusions: The stabilization after transitions into Episodes or Intervals and the destabilization after remaining for some time in either condition may be described as resulting from continuous processes building up during Episodes and Intervals. These processes underlie the overt occurrence of transitions. Citation: Bassi A; Vivaldi EA; Ocampo-Garcées A. The time course of the probability of transition into and out of REM sleep. SLEEP 2009

  18. Effect of Laparoscopic-assisted Gastropexy on Gastrointestinal Transit Time in Dogs.

    Science.gov (United States)

    Balsa, I M; Culp, W T N; Drobatz, K J; Johnson, E G; Mayhew, P D; Marks, S L

    2017-11-01

    Prophylactic gastropexy has been promoted as a means of preventing gastric volvulus during gastric dilatation and volvulus (GDV) syndrome. Little is known about the impact of gastropexy on gastrointestinal transit time. Laparoscopic-assisted gastropexy (LAG) will not alter gastrointestinal transit times when comparing gastric (GET), small and large bowel (SLBTT), and whole gut transit times (TTT) before and after surgery. 10 healthy client-owned large-breed dogs. Prospective clinical trial. Before surgery, all dogs underwent physical examination and diagnostic evaluation to ensure normal health status. Dogs were fed a prescription diet for 6 weeks before determination of gastrointestinal transit with a wireless motility capsule. LAG was then performed, and dogs were fed the diet for 6 additional weeks. Measurement of transit times was repeated 6 weeks after surgery. Ten dogs of various breeds at-risk for GDV were enrolled. No complications were encountered associated with surgery or capsule administration. There were no significant differences in GET 429 [306-1,370] versus 541 [326-1,298] (P = 0.80), SLBTT 1,243 [841-3,070] versus 1,540 [756-2,623] (P = 0.72), or TTT 1,971 [1,205-3,469] versus 1,792 [1,234-3,343] minutes (median, range) (P = 0.65) before and after LAG. An effect of LAG on gastrointestinal transit time was not identified, and wireless motility capsule can be safely administered in dogs after LAG. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  19. Unconventional Topological Phase Transition in Two-Dimensional Systems with Space-Time Inversion Symmetry

    Science.gov (United States)

    Ahn, Junyeong; Yang, Bohm-Jung

    2017-04-01

    We study a topological phase transition between a normal insulator and a quantum spin Hall insulator in two-dimensional (2D) systems with time-reversal and twofold rotation symmetries. Contrary to the case of ordinary time-reversal invariant systems, where a direct transition between two insulators is generally predicted, we find that the topological phase transition in systems with an additional twofold rotation symmetry is mediated by an emergent stable 2D Weyl semimetal phase between two insulators. Here the central role is played by the so-called space-time inversion symmetry, the combination of time-reversal and twofold rotation symmetries, which guarantees the quantization of the Berry phase around a 2D Weyl point even in the presence of strong spin-orbit coupling. Pair creation and pair annihilation of Weyl points accompanying partner exchange between different pairs induces a jump of a 2D Z2 topological invariant leading to a topological phase transition. According to our theory, the topological phase transition in HgTe /CdTe quantum well structure is mediated by a stable 2D Weyl semimetal phase because the quantum well, lacking inversion symmetry intrinsically, has twofold rotation about the growth direction. Namely, the HgTe /CdTe quantum well can show 2D Weyl semimetallic behavior within a small but finite interval in the thickness of HgTe layers between a normal insulator and a quantum spin Hall insulator. We also propose that few-layer black phosphorus under perpendicular electric field is another candidate system to observe the unconventional topological phase transition mechanism accompanied by the emerging 2D Weyl semimetal phase protected by space-time inversion symmetry.

  20. Trip time prediction in mass transit companies. A machine learning approach

    OpenAIRE

    João M. Moreira; Alípio Jorge; Jorge Freire de Sousa; Carlos Soares

    2005-01-01

    In this paper we discuss how trip time prediction can be useful foroperational optimization in mass transit companies and which machine learningtechniques can be used to improve results. Firstly, we analyze which departmentsneed trip time prediction and when. Secondly, we review related work and thirdlywe present the analysis of trip time over a particular path. We proceed by presentingexperimental results conducted on real data with the forecasting techniques wefound most adequate, and concl...

  1. Time-resolved small-angle neutron scattering of a micelle-to-vesicle transition

    Energy Technology Data Exchange (ETDEWEB)

    Egelhaaf, S U [Institut Max von Laue - Paul Langevin (ILL), 38 -Grenoble (France); Schurtenberger, P [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-04-01

    Amphiphilic molecules spontaneously self-assemble in solution to form a variety of aggregates. Only limited information is available on the kinetics of the structural transitions as well as on the existence of non-equilibrium or metastable states. Aqueous mixtures of lecithin and bile salt are very interesting biological model-systems which exhibit a spontaneous transition from polymer-like mixed micelles to vesicles upon dilution. The small-angle neutron scattering (SANS) instrument D22, with its very high neutron flux and the broad range of scattering vectors covered in a single instrumental setting, allowed us for the first time to perform time-resolved scattering experiments in order to study the micelle-to-vesicle transition. The temporal evolution of the aggregate structures were followed and detailed information was obtained even on molecular length-scales. (author). 5 refs.

  2. Observation of a Time Quasicrystal and Its Transition to a Superfluid Time Crystal

    Science.gov (United States)

    Autti, S.; Eltsov, V. B.; Volovik, G. E.

    2018-05-01

    We report experimental realization of a quantum time quasicrystal and its transformation to a quantum time crystal. We study Bose-Einstein condensation of magnons, associated with coherent spin precession, created in a flexible trap in superfluid 3He-B . Under a periodic drive with an oscillating magnetic field, the coherent spin precession is stabilized at a frequency smaller than that of the drive, demonstrating spontaneous breaking of discrete time translation symmetry. The induced precession frequency is incommensurate with the drive, and hence, the obtained state is a time quasicrystal. When the drive is turned off, the self-sustained coherent precession lives a macroscopically long time, now representing a time crystal with broken symmetry with respect to continuous time translations. Additionally, the magnon condensate manifests spin superfluidity, justifying calling the obtained state a time supersolid or a time supercrystal.

  3. Pase de guardia: información relevante y toma de decisiones en clínica médica: Estudio prospectivo Handoffs: relevant information and decision making in internal medicine: A prospective study

    Directory of Open Access Journals (Sweden)

    Andrea Vázquez

    2011-09-01

    Full Text Available Introducción. El pase de guardia es una actividad médica en la que se transfiere información y responsabilidad entre profesionales en situaciones de discontinuidad o transiciones en el cuidado de los pacientes. Los pases de guardia son fuente de errores médicos, a pesar de lo cual la programación formal en la competencia específica está ausente en los currículos de las residencias médicas. En este sentido, implementamos el proyecto educativo 'Pase de guardia oral y escrito en la residencia de clínica médica'. Materiales y métodos. Definimos el constructo 'información relevante' a partir de cinco ítems, uno sistémico y cuatro cognitivos. Se analizó la prevalencia de los déficits de información relevante y su repercusión sobre la práctica clínica. Resultados. En 230 protocolos de guardia, la prevalencia de déficits de información relevante fue del 31,3% (n = 72 y afectó tanto al ítem sistémico (11% como a los ítems con contenidos sustantivos (20%. Con información relevante, las conductas activas fueron del 34,6%, y las pasivas, del 65,4%; con déficits de información relevante, las activas fueron del 13,9%, y las pasivas, del 86,1%. Estas diferencias fueron significativas (p Introduction. Handoffs are medical activity which transfers information and responsibility among professionals in situations of discontinuity or transitions in patient care. Handoffs are source of medical errors and adverse events, which despite the formal programming of specific competencies are absent in the curricula of medical residencies. In this sense, we implemented the educational project 'Oral and written handoffs in internal medicine residency program'. Materials and methods. We defined the parameter relevant information with a systemic item and four other cognitive items; we assess the prevalence of relevant information deficits and the effects on the clinical practice in a prospective study. Results. In 230 protocols the prevalence of

  4. Lesions Responsible for Delayed Oral Transit Time in Post-stroke Dysphagia.

    Science.gov (United States)

    Moon, Hyun Im; Yoon, Seo Yeon; Yi, Tae Im; Jeong, Yoon Jeong; Cho, Tae Hwan

    2017-10-11

    Some stroke patients show oral phase dysphagia, characterized by a markedly prolonged oral transit time that hinders oral feeding. The aim of this study was to clarify the clinical characteristics and lesions responsible for delayed swallowing. We reviewed 90 patients with stroke. The oral processing time plus the postfaucial aggregation time required to swallow semisolid food was assessed. The patients were divided into two groups according to oral transit time, and we analyzed the differences in characteristics such as demographic factors, lesion factors, and cognitive function. Logistic regression analyses were performed to examine the predictors of delayed oral transit time. Lesion location and volume were measured on brain magnetic resonance images. We generated statistic maps of lesions related to delayed oral phase in swallowing using voxel-based lesion symptom mapping (VLSM). The group of patients who showed delayed oral transit time had significantly low cognitive function. Also, in a regression model, delayed oral phase was predicted with low K-MMSE (Korean version of the Mini Mental Status Exam). Using VLSM, we found the lesion location to be associated with delayed oral phase after adjusting for K-MMSE score. Although these results did not reach statistical significance, they showed the lesion pattern with predominant distribution in the left frontal lobe. Delayed oral phase in post-stroke patients was not negligible clinically. Patients' cognitive impairments affect the oral transit time. When adjusting it, we found a trend that the lesion responsible for delayed oral phase was located in the left frontal lobe, though the association did not reach significance. The delay might be related to praxis function.

  5. Transit time dispersion in pulmonary and systemic circulation: effects of cardiac output and solute diffusivity.

    Science.gov (United States)

    Weiss, Michael; Krejcie, Tom C; Avram, Michael J

    2006-08-01

    We present an in vivo method for analyzing the distribution kinetics of physiological markers into their respective distribution volumes utilizing information provided by the relative dispersion of transit times. Arterial concentration-time curves of markers of the vascular space [indocyanine green (ICG)], extracellular fluid (inulin), and total body water (antipyrine) measured in awake dogs under control conditions and during phenylephrine or isoproterenol infusion were analyzed by a recirculatory model to estimate the relative dispersions of transit times across the systemic and pulmonary circulation. The transit time dispersion in the systemic circulation was used to calculate the whole body distribution clearance, and an interpretation is given in terms of a lumped organ model of blood-tissue exchange. As predicted by theory, this relative dispersion increased linearly with cardiac output, with a slope that was inversely related to solute diffusivity. The relative dispersion of the flow-limited indicator antipyrine exceeded that of ICG (as a measure of intravascular mixing) only slightly and was consistent with a diffusional equilibration time in the extravascular space of approximately 10 min, except during phenylephrine infusion, which led to an anomalously high relative dispersion. A change in cardiac output did not alter the heterogeneity of capillary transit times of ICG. The results support the view that the relative dispersions of transit times in the systemic and pulmonary circulation estimated from solute disposition data in vivo are useful measures of whole body distribution kinetics of indicators and endogenous substances. This is the first model that explains the effect of flow and capillary permeability on whole body distribution of solutes without assuming well-mixed compartments.

  6. Magnet tracking allows assessment of regional gastrointestinal transit times in children

    Directory of Open Access Journals (Sweden)

    Hedsund C

    2013-11-01

    Full Text Available Caroline Hedsund,1,2 Iben Moeller Joensson,2 Tine Gregersen,1 Lotte Fynne,1 Vincent Schlageter,3 Klaus Krogh1 1Neurogastroenterology Unit, Department of Hepatology and Gastroenterology, 2Department of Pediatrics, Aarhus University Hospital, Aarhus, Denmark; 3Motilis Medica SA, Lausanne, Switzerland Background: Data on small intestinal transit time in healthy children are lacking, and normal values for gastric emptying and colonic transit time are sparse. Conventional methods, including radiopaque markers, scintigraphy, and PillCam™ involve radiation or require the child to swallow a large pill. The minimally invasive, radiation-free Motility Tracking System-1 (MTS-1 has been introduced for description of gastrointestinal motility in adults. The aim of the study was to evaluate the MTS-1 for assessment of gastrointestinal transit times and motility patterns in healthy children. Methods: Twenty-one healthy children (nine girls, median age 10 (range 7–12 years were included. For evaluation with MTS-1, a small magnetic pill was ingested and tracked through the gastrointestinal tract by a matrix of 16 magnetic sensors placed behind a nonmagnetic bed. The children were investigated for 8 hours after swallowing the magnetic pill and again for 4 hours the following morning. After leaving the unit, each child came back after every bowel movement to determine if the pill had been expelled. Results: Nineteen children could swallow the pill. Characteristic contraction patterns were identified for the stomach (three per minute, small intestine (9–11 per minute, and colon (4–5 per minute. Median total gastrointestinal transit time was 37.7 (range 9.5–95.8 hours, median gastric emptying time was 37 (range 2–142 minutes, median small intestinal transit time was 302 (range 164 to >454 minutes, and median colorectal transit time was 38.1 (range 5.6–90.0 hours. Conclusion: MTS-1 allows minimally invasive evaluation of gastrointestinal motility in

  7. The Measurement of Time: Children's Construction of Transitivity, Unit Iteration, and Conservation of Speed.

    Science.gov (United States)

    Long, Kathy; Kamii, Constance

    2001-01-01

    Interviews 120 children in kindergarten and grades 2, 4, and 6 with five Piagetian tasks to determine the grade level at which most have constructed transitive reasoning, unit iteration, and conservation of speed. Indicates that construction of the logic necessary to make sense of the measurement of time is generally not complete before sixth…

  8. Influence of orocaecal transit time on hydrogen excretion after carbohydrate malabsorption

    DEFF Research Database (Denmark)

    Rumessen, J J; Hamberg, O; Gudmand-Høyer, E

    1989-01-01

    The aim of the present study was to determine whether changes in orocaecal transit time (OCTT) affect the magnitude of the breath hydrogen (H2) excretion after ingestion of unabsorbable carbohydrate. We studied eight healthy subjects by interval sampling of end expiratory H2 concentration for 12...

  9. Quantum processes: probability fluxes, transition probabilities in unit time and vacuum vibrations

    International Nuclear Information System (INIS)

    Oleinik, V.P.; Arepjev, Ju D.

    1989-01-01

    Transition probabilities in unit time and probability fluxes are compared in studying the elementary quantum processes -the decay of a bound state under the action of time-varying and constant electric fields. It is shown that the difference between these quantities may be considerable, and so the use of transition probabilities W instead of probability fluxes Π, in calculating the particle fluxes, may lead to serious errors. The quantity W represents the rate of change with time of the population of the energy levels relating partly to the real states and partly to the virtual ones, and it cannot be directly measured in experiment. The vacuum background is shown to be continuously distorted when a perturbation acts on a system. Because of this the viewpoint of an observer on the physical properties of real particles continuously varies with time. This fact is not taken into consideration in the conventional theory of quantum transitions based on using the notion of probability amplitude. As a result, the probability amplitudes lose their physical meaning. All the physical information on quantum dynamics of a system is contained in the mean values of physical quantities. The existence of considerable differences between the quantities W and Π permits one in principle to make a choice of the correct theory of quantum transitions on the basis of experimental data. (author)

  10. Simultaneous Optimization of Container Ship Sailing Speed and Container Routing with Transit Time Restrictions

    DEFF Research Database (Denmark)

    Karsten, Christian Vad; Røpke, Stefan; Pisinger, David

    We introduce a decision support tool for liner shipping companies to optimally determine the sailing speed and needed fleet for a global network. As a novelty we incorporate cargo routing decisions with tight transit time restrictions on each container such that we get a realistic picture...

  11. Splitting the scotoperiod: effects on feeding behaviour, intestinal fill and digestive transit time in broiler chickens

    DEFF Research Database (Denmark)

    Duve, Linda Rosager; Steenfeldt, Sanna; Thodberg, Karen

    2011-01-01

    points (n¼192). Digestive transit time was estimated on d 29 using a chromic oxide marker; production variables and the extent of foot pad dermatitis were also recorded. 4. In the 3 h prior to a scotoperiod, feeding activity increased in chickens from DARK 8 but not DARK 4þ4. This increase was reflected...

  12. The effect of coffee on gastric emptying and oro-caecal transit time

    NARCIS (Netherlands)

    Boekema, P. J.; Lo, B.; Samsom, M.; Akkermans, L. M.; Smout, A. J.

    2000-01-01

    BACKGROUND: The consumption of coffee allegedly induces or aggravates gastrointestinal symptoms. In order to investigate the effect of coffee on gastrointestinal motility we studied the effect of coffee on gastric emptying and oro-caecal transit time. METHODS: In a randomised, controlled, cross-over

  13. Real-time monitoring of clinical processes using complex event processing and transition systems.

    Science.gov (United States)

    Meinecke, Sebastian

    2014-01-01

    Dependencies between tasks in clinical processes are often complex and error-prone. Our aim is to describe a new approach for the automatic derivation of clinical events identified via the behaviour of IT systems using Complex Event Processing. Furthermore we map these events on transition systems to monitor crucial clinical processes in real-time for preventing and detecting erroneous situations.

  14. Scintigraphic determination of gastrointestinal transit times. A comparison with breath hydrogen and radiologic methods

    DEFF Research Database (Denmark)

    Madsen, J L; Larsen, N E; Hilsted, J

    1991-01-01

    A scintigraphic method for determination of gastrointestinal transit times was compared with the breath hydrogen test and a multiple-bolus, single-radiograph technique. A close temporal association was found between the caecal appearance of radioactivity and the onset of breath hydrogen excretion...... the breath hydrogen concentration profiles....

  15. Dating Violence, Bullying, and Sexual Harassment: Longitudinal Profiles and Transitions over Time

    Science.gov (United States)

    Miller, Shari; Williams, Jason; Cutbush, Stacey; Gibbs, Deborah; Clinton-Sherrod, Monique; Jones, Sarah

    2013-01-01

    Although there is growing recognition of the problem of dating violence, little is known about how it unfolds among young adolescents who are just beginning to date. This study examined classes (subgroups) and transitions between classes over three time points based on dating violence, bullying, and sexual harassment perpetration and victimization…

  16. Defaecation disorders in children, colonic transit time versus the Barr-score

    NARCIS (Netherlands)

    Benninga, M. A.; Büller, H. A.; Staalman, C. R.; Gubler, F. M.; Bossuyt, P. M.; van der Plas, R. N.; Taminiau, J. A.

    1995-01-01

    It is still unclear how to evaluate the existence of faecal retention or impaction in children with defaecation disorders. To objectivate the presence and degree of constipation we measured segmental and total colonic transit times (CTT) using radio-opaque markers in 211 constipated children. On

  17. Colonic transit time relates to bacterial metabolism and mucosal turnover in the human gut

    DEFF Research Database (Denmark)

    Roager, Henrik Munch; Hansen, Lea Benedicte Skov; Bahl, Martin Iain

    catabolism as reflected by microbial metabolites in urine. This results in a number of potentially deleterious protein-derived metabolites. Additionally, longer colonic transit time correlates with metabolites likely reflecting reduced renewal of the colonic mucosa. Together, this suggests that a high gut...

  18. Validation of a 1-mm transit time flow probe and the potential for use in microsurgery

    DEFF Research Database (Denmark)

    Bonde, Christian T; Elberg, Jens J; Holstein-Rathlou, N.-H.

    2006-01-01

    The objective of this study was to validate a prototype transit time ultrasound flow probe (Medi-Stim Butterfly Flowmeter BF 2004) of only 1 mm and to evaluate its potential for use in microsurgery. Knowledge of the ability of this kind of system to measure flow in small vessels and at small flow...

  19. Increasing accuracy of pulse transit time measurements by automated elimination of distorted photoplethysmography waves

    NARCIS (Netherlands)

    M.H.N. van Velzen (M. H N); A.J. Loeve (Arjo J.); S.P. Niehof (Sjoerd); E.G. Mik (Egbert)

    2017-01-01

    textabstractPhotoplethysmography (PPG) is a widely available non-invasive optical technique to visualize pressure pulse waves (PWs). Pulse transit time (PTT) is a physiological parameter that is often derived from calculations on ECG and PPG signals and is based on tightly defined characteristics of

  20. Increasing accuracy of pulse transit time measurements by automated elimination of distorted photoplethysmography waves

    NARCIS (Netherlands)

    van Velzen, M.H.N.; Loeve, A.J.; Niehof, S.P.; Mik, E.G.

    2017-01-01

    Photoplethysmography (PPG) is a widely available non-invasive optical technique to visualize pressure pulse waves (PWs). Pulse transit time (PTT) is a physiological parameter that is often derived from calculations on ECG and PPG signals and is based on tightly defined characteristics of the PW

  1. FDTD based transition time dependent crosstalk analysis for coupled RLC interconnects

    International Nuclear Information System (INIS)

    Sharma, Devendra Kumar; Kaushik, Brajesh Kumar; Sharma, R. K.

    2014-01-01

    The performance of high density chips operating in the GHz range is mostly affected by on-chip interconnects. The interconnect delay depends on many factors, a few of them are inputs toggling patterns, line and coupling parasitics, input rise/fall time and source/load characteristics. The transition time of the input is of prime importance in high speed circuits. This paper addresses the FDTD based analysis of transition time effects on functional and dynamic crosstalk. The analysis is carried out for equal and unequal transition times of coupled inputs. The analysis of the effects of unequal rise time is equally important because practically, it is quite common to have mismatching in the rise time of the signals transmitting through different length wires. To demonstrate the effects, two distributed RLC lines coupled inductively and capacitively are taken into consideration. The FDTD technique is used because it gives accurate results and carries time domain analysis of coupled lines. The number of lumps in SPICE simulations is considered the same as those of spatial segments. To validate the FDTD computed results, SPICE simulations are run and results are compared. A good agreement of the computed results has been observed with respect to SPICE simulated results. An average error of less than 3.2% is observed in the computation of the performance parameters using the proposed method. (semiconductor integrated circuits)

  2. Examining the Experiences of Athletic Trainers as they transition into their First Full-Time Position

    OpenAIRE

    Stephanie M. Mazerolle; McLain Whitney; Christy Eason

    2017-01-01

    Transition to clinical practice is an important topic in athletic training, as it can be a period of time that presents challenges for the athletic trainer. Most of the research pertaining to transition to practice focuses on the skills and knowledge necessary for clinical practice, yet we know that stress can manifest from not only being an independent practitioner but also from learning how to balance one’s roles. We wanted to understand the perspective of today’s novice athletic trainers a...

  3. Establishment of a protocol for determining gastrointestinal transit time in mice using barium and radiopaque markers

    Energy Technology Data Exchange (ETDEWEB)

    Myagmarjaibuu, Bilomaa; Moon, Myeong Ju; Heo, Suk Hee; Jeong, Seo In; Jeong, Yong Yeon; Kang, Heoung Keun [Dept. of Radiology, Chonnam National University Hwasun Hospital, Chonnam National University Medical School, Hwasun (Korea, Republic of); Park, Jong Seong [Dept. of Physiology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Jun, Jae Yeoul [Dept. of Physiology, College of Medicine, Chosun University, Gwangju (Korea, Republic of)

    2013-01-15

    The purpose of this study was to establish a minimally invasive and reproducible protocol for estimating the gastrointestinal (GI) transit time in mice using barium and radiopaque markers. Twenty 5- to 6-week-old Balb/C female mice weighing 19-21 g were used. The animals were divided into three groups: two groups that received loperamide and a control group. The control group (n = 10) animals were administered physiological saline (1.5 mL/kg) orally. The loperamide group I (n = 10) and group II (n = 10) animals were administered 5 mg/kg and 10 mg/kg loperamide orally, respectively. Thirty minutes after receiving the saline or loperamide, the mice was administered 80 μL of barium solution and six iron balls (0.5 mm) via the mouth and the upper esophagus by gavage, respectively. Afterwards, the mice were continuously monitored with fluoroscopic imaging in order to evaluate the swallowing of the barium solution and markers. Serial fluoroscopic images were obtained at 5- or 10-min intervals until all markers had been excreted from the anal canal. For analysis, the GI transit times were subdivided into intestinal transit times (ITTs) and colon transit times (CTTs). The mean ITT was significantly longer in the loperamide groups than in the control group (p < 0.05). The mean ITT in loperamide group II (174.5 ± 32.3) was significantly longer than in loperamide group I (133.2 ± 24.2 minute) (p < 0.05). The mean CTT was significantly longer in loperamide group II than in the control group (p < 0.05). Also, no animal succumbed to death after the experimental procedure. The protocol for our study using radiopaque markers and barium is reproducible and minimally invasive in determining the GI transit time of the mouse model.

  4. Flow-rate measurement using radioactive tracers and transit time method

    International Nuclear Information System (INIS)

    Turtiainen, Heikki

    1986-08-01

    The transit time method is a flow measurement method based on tracer techniques. Measurement is done by injecting to the flow a pulse of tracer and measuring its transit time between two detection positions. From the transit time the mean flow velosity and - using the pipe cross section area - the volume flow rate can be calculated. When a radioisotope tracer is used the measurement can be done from outside the pipe and without disturbing the process (excluding the tracer injection). The use of the transit time method has been limited because of difficulties associated with handling and availability of radioactive tracers and lack of equipment suitable for routine use in industrial environments. The purpose of this study was to find out if these difficulties may be overcome by using a portable isotope generator as a tracer source and automating the measurement. In the study a test rig and measuring equipment based on the use of a ''1''3''7Cs/''1''3''7''''mBa isotope generator were constructed. They were used to study the accuracy and error sources of the method and to compare different algorithms to calculate the transit time. The usability of the method and the equipment in industrial environments were studied by carrying out over 20 flow measurements in paper and pulp mills. On the basis of the results of the study, a project for constructing a compact radiatracer flowmeter for industrial use has been started. The application range of this kind of meter is very large. The most obvious applications are in situ calibration of flowmeters, material and energy balance studies, process equipment analyses (e.g. pump efficiency analyses). At the moment tracer techniques are the only methods applicable to these measurements on-line and with sufficient accuracy

  5. Using Start/End Timings of Spectral Transitions Between Phonemes in Concatenative Speech Synthesis

    OpenAIRE

    Toshio Hirai; Seiichi Tenpaku; Kiyohiro Shikano

    2002-01-01

    The definition of "phoneme boundary timing" in a speech corpus affects the quality of concatenative speech synthesis systems. For example, if the selected speech unit is not appropriately match to the speech unit of the required phoneme environment, the quality may be degraded. In this paper, a dynamic segment boundary defi- nition is proposed. In the definition, the concatenation point is chosen from the start or end timings of spectral transition depending on the phoneme environment at the ...

  6. Idealized flow patterns and transit times in gas/liquid contacting trays with multiple box downcomers

    International Nuclear Information System (INIS)

    D'Arcy, D.

    1977-08-01

    Trays with multiple box downcomers are often used in chemical process plants nowadays. In order to make a theoretical assessment of the mass transfer efficiency of such trays, knowledge is needed of the time spent by the liquid at various parts of the tray. An idealized but reasonable flow pattern has been assumed and the local velocities and transit times along ten equally-spaced stream lines have been computed. Numerical and graphical results are presented. (author)

  7. Time-dependent transitions with time–space noncommutativity and its implications in quantum optics

    International Nuclear Information System (INIS)

    Chandra, Nitin

    2012-01-01

    We study the time-dependent transitions of a quantum-forced harmonic oscillator in noncommutative R 1,1 perturbatively to linear order in the noncommutativity θ. We show that the Poisson distribution gets modified, and that the vacuum state evolves into a ‘squeezed’ state rather than a coherent state. The time evolutions of uncertainties in position and momentum in vacuum are also studied and imply interesting consequences for modeling nonlinear phenomena in quantum optics. (paper)

  8. The pursuit of new role: A study of luxury products consumption during the liminal transition into first time employment

    OpenAIRE

    Chucherd, Sunong

    2008-01-01

    Consumer behaviour research on role transition has so far been limited to the negative life changes and the changes-specific consequences towards the consumption pattern. Moreover, although young adult customers have recently been the new target customer for many luxury brands, no research has been conducted concerning the impacts of role transition during the transition into first-time employment and the role of luxury products in dealing with those effects. Liminal transition is also a new ...

  9. Transit Timing Variation analysis with Kepler light curves of KOI 227 and Kepler 93b

    Science.gov (United States)

    Dulz, Shannon; Reed, Mike

    2017-01-01

    By searching for transit signals in approximately 150,000 stars, NASA’s Kepler Space telescope found thousands of exoplanets over its primary mission from 2009 to 2013 (Tenenbaum et al. 2014, ApJS, 211, 6). Yet, a detailed follow-up examination of Kepler light curves may contribute more evidence on system dynamics and planetary atmospheres of these objects. Kepler’s continuous observing of these systems over the mission duration produced light curves of sufficient duration to allow for the search for transit timing variations. Transit timing variations over the course of many orbits may indicate a precessing orbit or the existence of a non-transiting third body such as another exoplanet. Flux contributions of the planet just prior to secondary eclipse may provide a measurement of bond albedo from the day-side of the transiting planet. Any asymmetries of the transit shape may indicate thermal asymmetries which can measure upper atmosphere motion of the planet. These two factors can constrain atmospheric models of close orbiting exoplanets. We first establish our procedure with the well-documented TTV system, KOI 227 (Nesvorny et al. 2014, ApJ, 790, 31). Using the test case of KOI 227, we analyze Kepler-93b for TTVs and day-side flux contributions. Kepler-93b is likely a rocky planet with R = 1.50 ± 0.03 Earth Radii and M = 2.59 ± 2.0 Earth Masses (Marcy et al. 2014, ApJS, 210, 20). This research is funded by a NASA EPSCoR grant.

  10. Determination of global and regional heart functions with minimum transit times

    International Nuclear Information System (INIS)

    Feinendegen, L.E.; Becker, V.; Vyska, K.; Freundlieb, C.; Bosiljanoff, P.

    1980-01-01

    The minimum transit time obviously represents the most constant flow parameter. By means of a constant, that was chosen to be 1.2 for cardiac flow, it is equal to the quotient of volume to flow and is also inversely related proportional to the fraction of ejection that is concerned. The first indicator passage through the heart is measured for the minimum cardiac transit time, whereby interesting regions were chosen for the two auricula, the two ventricula, the pulmonary artery and the aorta. The time activity characteristica obtained from the particular regions need a special smoothing by means of the gliding mean, so that the arrival times can easily be recognized. This way in one examination process the differences of arrival times respectively the minimal transit times can be obtained for each particular cardiac segment, the pulmonary circuit and the whole cardio-pulmonary circuit. The advantages of minimum cardiac transit time measurements are the simplicity and the speed of the noninvasive functional diagnostic with lower radiation load and accuracy and reproductability with low error limits, especially for the whole cardio-pulmonary MTT. The simultaneous acquisition of multiple cardiac segments is to emphasize a special way. For its particular values similar error widths were found as for the left ventricular function measurement with the triggered scintigraphy of the interior of the heart. A further advantage of the measurement is an almost problem-less application in body load. Therefore the MTT-measurement is especially useful for preventive diagnostics of coronary diseases. A combination of MTT-measurements of all segments of the small circuit with the triggered scintigraphy of the interior of the heart for analysis of regional left-ventricular ejection fractions and left-ventricular wall movements would essentially enrich the noninvasive cardiac diagnostics. (orig./APR) [de

  11. Sum Utilization of Spectrum with Spectrum Handoff and Imperfect Sensing in Interweave Multi-Channel Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    Waqas Khalid

    2018-05-01

    Full Text Available Fifth-generation (5G heterogeneous network deployment poses new challenges for 5G-based cognitive radio networks (5G-CRNs as the primary user (PU is required to be more active because of the small cells, random user arrival, and spectrum handoff. Interweave CRNs (I-CRNs improve spectrum utilization by allowing opportunistic spectrum access (OSA for secondary users (SUs. The sum utilization of spectrum, i.e., joint utilization of spectrum by the SU and PU, depends on the spatial and temporal variations of PU activities, sensing outcomes, transmitting conditions, and spectrum handoff. In this study, we formulate and analyze the sum utilization of spectrum with different sets of channels under different PU and SU co-existing network topologies. We consider realistic multi-channel scenarios for the SU, with each channel licensed to a PU. The SU, aided by spectrum handoff, is authorized to utilize the channels on the basis of sensing outcomes and PU interruptions. The numerical evaluation of the proposed work is presented under different network and sensing parameters. Moreover, the sum utilization gain is investigated to analyze the sensitivities of different sensing parameters. It is demonstrated that different sets of channels, PU activities, and sensing outcomes have a significant impact on the sum utilization of spectrum associated with a specific network topology.

  12. Detection of weak transitions in signal dynamics using recurrence time statistics

    International Nuclear Information System (INIS)

    Gao, J.B.; Cao Yinhe; Gu Lingyun; Harris, J.G.; Principe, J.C.

    2003-01-01

    Signal detection in noisy and nonstationary environments is very challenging. In this Letter, we study why the two types of recurrence times [Phys. Rev. Lett. 83 (1999) 3178] may be very useful for detecting weak transitions in signal dynamics. We particularly emphasize that the recurrence times of the second type may be more powerful in detecting transitions with very low energy. These features are illustrated by studying a number of speech signals with fricatives and plosives. We have also shown that the recurrence times of the first type, nevertheless, has the distinguished feature of being more robust to the noise level and less sensitive to the parameter change of the algorithm. Since throughout our study, we have not explored any features unique to the speech signals, the results shown here may indicate that these tools may be useful in many different applications

  13. Mean transit time image - a new method of analyzing brain perfusion studies

    Energy Technology Data Exchange (ETDEWEB)

    Szabo, Z.; Ritzl, F.

    1983-05-01

    Point-by-point calculation of the mean transit time based on gamma fit was used to analyze brain perfusion studies in a vertex view. The algorithm and preliminary results in normal brain and in different stages of cerebral perfusion abnormality (ischemia, stroke, migraine, tumor, abscess) are demonstrated. In contrast to the traditional methods using fixed, a priori defined regions of interest this type of mapping of the relative regions cerebral perfusion shows more clearly the irregular outlines of the disturbance. Right to left activity ratios in the arterial part of the time-activity curves showed significant correlation with the mean transit time ratios (Q/sub 1/=1.185-0.192 Qsub(a), n=38, r=0.716, P<0.001).

  14. Time-frequency analysis of the restricted three-body problem: transport and resonance transitions

    International Nuclear Information System (INIS)

    Vela-Arevalo, Luz V; Marsden, Jerrold E

    2004-01-01

    A method of time-frequency analysis based on wavelets is applied to the problem of transport between different regions of the solar system, using the model of the circular restricted three-body problem in both the planar and the spatial versions of the problem. The method is based on the extraction of instantaneous frequencies from the wavelet transform of numerical solutions. Time-varying frequencies provide a good diagnostic tool to discern chaotic trajectories from regular ones, and we can identify resonance islands that greatly affect the dynamics. Good accuracy in the calculation of time-varying frequencies allows us to determine resonance trappings of chaotic trajectories and resonance transitions. We show the relation between resonance transitions and transport in different regions of the phase space

  15. Particle identification using the time-over-threshold method in the ATLAS Transition Radiation Tracker

    International Nuclear Information System (INIS)

    Akesson, T.; Arik, E.; Assamagan, K.; Baker, K.; Barberio, E.; Barberis, D.; Bertelsen, H.; Bytchkov, V.; Callahan, J.; Catinaccio, A.; Danielsson, H.; Dittus, F.; Dolgoshein, B.; Dressnandt, N.; Ebenstein, W.L.; Eerola, P.; Farthouat, P.; Froidevaux, D.; Grichkevitch, Y.; Hajduk, Z.; Hansen, J.R.; Keener, P.T.; Kekelidze, G.; Konovalov, S.; Kowalski, T.; Kramarenko, V.A.; Krivchitch, A.; Laritchev, A.; Lichard, P.; Lucotte, A.; Lundberg, B.; Luehring, F.; Mailov, A.; Manara, A.; McFarlane, K.; Mitsou, V.A.; Morozov, S.; Muraviev, S.; Nadtochy, A.; Newcomer, F.M.; Olszowska, J.; Ogren, H.; Oh, S.H.; Peshekhonov, V.; Rembser, C.; Romaniouk, A.; Rousseau, D.; Rust, D.R.; Schegelsky, V.; Sapinski, M.; Shmeleva, A.; Smirnov, S.; Smirnova, L.N.; Sosnovtsev, V.; Soutchkov, S.; Spiridenkov, E.; Tikhomirov, V.; Van Berg, R.; Vassilakopoulos, V.; Wang, C.; Williams, H.H.

    2001-01-01

    Test-beam studies of the ATLAS Transition Radiation Tracker (TRT) straw tube performance in terms of electron-pion separation using a time-over-threshold method are described. The test-beam data are compared with Monte Carlo simulations of charged particles passing through the straw tubes of the TRT. For energies below 10 GeV, the time-over-threshold method combined with the standard transition-radiation cluster-counting technique significantly improves the electron-pion separation in the TRT. The use of the time-over-threshold information also provides some kaon-pion separation, thereby significantly enhancing the B-physics capabilities of the ATLAS detector

  16. Challenges to Rainfall-Runoff and Transit Time Distribution Modeling Within the Southeastern Coastal Plain, USA

    Science.gov (United States)

    Decker, P.; Cohen, M. J.; Jawitz, J. W.

    2017-12-01

    Previous hydrologic studies primarily focus on processes related to montane catchments with significant runoff ratios, low evapotranspiration rates, and reasonably short travel times. There is a significant lack of research for hydrologic processes occurring within the United States Southeastern Coastal Plain landscape where low-relief and high rates of evapotranspiration impact water fluxes. Hydrologic modeling efforts within this region may elucidate possible interactions and timescales of solute travel where much of the landscape is managed for agricultural crops, namely plantation forestry. A long-term paired watershed study carried out in northern Florida monitored two second-order blackwater streams for five years. Rainfall-runoff models for both catchments were created using daily discharge, precipitation, and modeled evapotranspiration as input parameters. Best fit occurred (NSE = 0.8) when the catchments were modeled as two-storage (shallow and deep) reservoirs in parallel and overland flow was allowed to contribute to streamflow in periods were shallow groundwater storage was at capacity. In addition, streamflow and rainfall chloride concentrations were used to model in-variable transit time distributions using spectral methods. In both catchments this transit time was unresolvable because output spectral power exceeded input spectral power, a result assumed to be driven by the evaporative demand of the region. A modeled chloride time series from random input concentration and modeled output through the rainfall-runoff model was used to alter the evaporation ratio. Once evaporation rates equaled known rates found in cool, high-relief catchments, spectral analysis illustrated higher input spectral power and therefore resolvable transit times. Findings from this study illustrate significant effects from evaporation within the catchment - often exceeding the signal from the background catchment process itself. Calculations illustrate a proposed mean transit

  17. Accelerating the transit time of barium sulphate suspensions in small bowel examinations

    International Nuclear Information System (INIS)

    Summers, David S.; Roger, Mark D.; Allan, Paul L.; Murchison, John T.

    2007-01-01

    Purpose: To determine whether hyperosmolar and effervescent agents proven individually to accelerate transit time in the barium small bowel examination have an additive effect when combined, surpassing that of either agent alone. Materials and methods: One hundred and forty-nine patients were randomised to four groups. Three hundred milliliters of barium sulphate alone was given to the first group. Fifteen milliliters of iodinated hyperosmolar contrast agent (Gastrografin, meglumine/sodium diatrizoate, Schering) was given in addition to barium sulphate to the second group while six packets of effervescent granules (Carbex, Ferring) were added for the third group. The final group was given a combination of both additives and barium sulphate. The time taken following ingestion for the contrast column to reach the caecum, as assessed by frequent interval fluoroscopy, was recorded. A subgroup of 32 patients were selected randomly from the four groups, 8 from each and assessed for quality of examination. Statistical assessments were made using Kruskal-Wallis and Mann-Whitney tests. Results: One hundred and nineteen patients were analysed after exclusions. The addition of accelerant to barium sulphate, both individually and in combination significantly reduced the small bowel transit time (p < 0.001). No significant difference existed between the additives when used with barium alone. The combined group had significantly faster transit times compared to the hyperosmolar group (p = 0.02). Differences between combined and effervescent groups tended towards significance (p = 0.09). No significant difference existed between groups when examination quality was assessed. Conclusion: These results suggest that the addition of combined effervescent and hyperosmolar agents to the barium suspension may significantly shorten the small bowel transit time without adversely affecting examination quality. This has implications for patient acceptability of the examination as well as

  18. Simplified assessment of segmental gastrointestinal transit time with orally small amount of barium

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Weitang; Zhang, Zhiyong; Liu, Jinbo; Li, Zhen; Song, Junmin; Wu, Changcai [Department of Colorectal Surgery, The First Affiliated Hospital and Institute of Clinical Medicine, Zhengzhou University, 450052 Zhengzhou (China); Wang, Guixian, E-mail: guixianwang@hotmail.com [Department of Colorectal Surgery, The First Affiliated Hospital and Institute of Clinical Medicine, Zhengzhou University, 450052 Zhengzhou (China)

    2012-09-15

    Objective: To determine the effectiveness and advantage of small amount of barium in the measurement of gastrointestinal transmission function in comparison with radio-opaque pallets. Methods: Protocal 1: 8 healthy volunteers (male 6, female 2) with average age 40 ± 6.1 were subjected to the examination of radio-opaque pellets and small amount of barium with the interval of 1 week. Protocol 2: 30 healthy volunteers in group 1 (male 8, female 22) with average age 42.5 ± 8.1 and 50 patients with chronic functional constipation in group 2 (male 11, female 39) with average age 45.7 ± 7.8 were subjected to the small amount of barium examination. The small amount of barium was made by 30 g barium dissolved in 200 ml breakfast. After taking breakfast which contains barium, objectives were followed with abdominal X-ray at 4, 8, 12, 24, 48, 72, 96 h until the barium was evacuated totally. Results: Small amount of barium presented actual chyme or stool transit. The transit time of radio-opaque pallets through the whole gastrointestinal tract was significantly shorter than that of barium (37 ± 8 h vs. 47 ± 10 h, P < 0.05) in healthy people. The transit times of barium in constipation patients were markedly prolonged in colon (61.1 ± 22 vs. 37.3 ± 11, P < 0.01) and rectum (10.8 ± 3.7 vs. 2.3 ± 0.8 h, P < 0.01) compared with unconstipated volunteers. Transit times in individual gastrointestinal segments were also recorded by using small amount of barium, which allowed identifying the subtypes of constipation. Conclusion: The small amount barium examination is a convenient and low cost method to provide the most useful and reliable information on the transmission function of different gastrointestinal segments and able to classify the subtypes of slow transit constipation.

  19. Simplified assessment of segmental gastrointestinal transit time with orally small amount of barium

    International Nuclear Information System (INIS)

    Yuan, Weitang; Zhang, Zhiyong; Liu, Jinbo; Li, Zhen; Song, Junmin; Wu, Changcai; Wang, Guixian

    2012-01-01

    Objective: To determine the effectiveness and advantage of small amount of barium in the measurement of gastrointestinal transmission function in comparison with radio-opaque pallets. Methods: Protocal 1: 8 healthy volunteers (male 6, female 2) with average age 40 ± 6.1 were subjected to the examination of radio-opaque pellets and small amount of barium with the interval of 1 week. Protocol 2: 30 healthy volunteers in group 1 (male 8, female 22) with average age 42.5 ± 8.1 and 50 patients with chronic functional constipation in group 2 (male 11, female 39) with average age 45.7 ± 7.8 were subjected to the small amount of barium examination. The small amount of barium was made by 30 g barium dissolved in 200 ml breakfast. After taking breakfast which contains barium, objectives were followed with abdominal X-ray at 4, 8, 12, 24, 48, 72, 96 h until the barium was evacuated totally. Results: Small amount of barium presented actual chyme or stool transit. The transit time of radio-opaque pallets through the whole gastrointestinal tract was significantly shorter than that of barium (37 ± 8 h vs. 47 ± 10 h, P < 0.05) in healthy people. The transit times of barium in constipation patients were markedly prolonged in colon (61.1 ± 22 vs. 37.3 ± 11, P < 0.01) and rectum (10.8 ± 3.7 vs. 2.3 ± 0.8 h, P < 0.01) compared with unconstipated volunteers. Transit times in individual gastrointestinal segments were also recorded by using small amount of barium, which allowed identifying the subtypes of constipation. Conclusion: The small amount barium examination is a convenient and low cost method to provide the most useful and reliable information on the transmission function of different gastrointestinal segments and able to classify the subtypes of slow transit constipation

  20. Examining the Experiences of Athletic Trainers as they transition into their First Full-Time Position

    Directory of Open Access Journals (Sweden)

    Stephanie M. Mazerolle

    2017-04-01

    Full Text Available Transition to clinical practice is an important topic in athletic training, as it can be a period of time that presents challenges for the athletic trainer. Most of the research pertaining to transition to practice focuses on the skills and knowledge necessary for clinical practice, yet we know that stress can manifest from not only being an independent practitioner but also from learning how to balance one’s roles. We wanted to understand the perspective of today’s novice athletic trainers and how they feel in their first full-time position, specifically relating to their professional development and establishment or maintenance of work-life balance (WLB. Using a qualitative paradigm, we phone interviewed athletic trainers who were categorized as career starters by the National Athletic Trainers’ Association. Using a purposive recruitment strategy we were able to recruit 20 (12 female, 8 male athletic trainers meeting this classification. General inductive analyses were used to code the data from our interviews, and we satisfied credibility though saturation of the data, peer review, and researcher triangulations during the coding process. Our findings suggest that while confidence in clinical skills is apparent, some of the more administrative aspects of clinical practice present challenges. We found that various employment settings offered various expectations or challenges that had the potential to impact WLB. A blend of professional and organizational processes helped transition the athletic trainer, and although both were helpful each also could be bolstered to improve transitioning for the newly credentialed athletic trainer. Employers of early career starters should be aware of the stress related to transition to practice, and the time it can take to acclimate.

  1. Relations between transit time, fermentation products, and hydrogen consuming flora in healthy humans.

    Science.gov (United States)

    El Oufir, L; Flourié, B; Bruley des Varannes, S; Barry, J L; Cloarec, D; Bornet, F; Galmiche, J P

    1996-06-01

    To investigate whether transit time could influence H2 consuming flora and certain indices of colonic bacterial fermentation. Eight healthy volunteers (four methane excretors and four non-methane excretors) were studied for three, three week periods during which they received a controlled diet alone (control period), and then the same diet with cisapride or loperamide. At the end of each period, mean transit time (MTT) was estimated, an H2 lactulose breath test was performed, and stools were analysed. In the control period, transit time was inversely related to faecal weight, sulphate reducing bacteria counts, concentrations of total short chain fatty acids (SCFAs), propionic and butyric acids, and H2 excreted in breath after lactulose ingestion. Conversely, transit time was positively related to faecal pH and tended to be related to methanogen counts. Methanogenic bacteria counts were inversely related to those of sulphate reducing bacteria and methane excretors had slower MTT and lower sulphate reducing bacteria counts than non-methane excretors. Compared with the control period, MTT was significantly shortened (p < 0.05) by cisapride and prolonged (p < 0.05) by loperamide (73 (11) hours, 47 (5) hours and 147 (12) hours for control, cisapride, and loperamide, respectively, mean (SD)). Cisapride reduced transit time was associated with (a) a significant rise in faecal weight, sulphate reducing bacteria, concentrations of total SCFAs, and propionic and butyric acids and breath H2 as well as (b) a significant fall in faecal pH and breath CH4 excretion, and (c) a non-significant decrease in the counts of methanogenic bacteria. Reverse relations were roughly the same during the loperamide period including a significant rise in the counts of methanogenic bacteria and a significant fall in those of sulphate reducing bacteria. Transit time differences between healthy volunteers are associated with differences in H2 consuming flora and certain indices of colonic

  2. Does the Timing of Transition Matter? Comparison of German Students' Self-Perceptions before and after Transition to Secondary School

    Science.gov (United States)

    Arens, A. Katrin; Yeung, Alexander Seeshing; Craven, Rhonda G.; Watermann, Rainer; Hasselhorn, Marcus

    2013-01-01

    The often observed decline in students' self-perceptions across transition to secondary school after grade 6 is often attributed to students' entry to puberty. This study aims to examine whether lowered self-perceptions can be observed after transition in Germany which occurs after grade 4 and thus takes place before puberty. Fifth graders (N =…

  3. Temperature-Controlled High-Speed AFM: Real-Time Observation of Ripple Phase Transitions.

    Science.gov (United States)

    Takahashi, Hirohide; Miyagi, Atsushi; Redondo-Morata, Lorena; Scheuring, Simon

    2016-11-01

    With nanometer lateral and Angstrom vertical resolution, atomic force microscopy (AFM) has contributed unique data improving the understanding of lipid bilayers. Lipid bilayers are found in several different temperature-dependent states, termed phases; the main phases are solid and fluid phases. The transition temperature between solid and fluid phases is lipid composition specific. Under certain conditions some lipid bilayers adopt a so-called ripple phase, a structure where solid and fluid phase domains alternate with constant periodicity. Because of its narrow regime of existence and heterogeneity ripple phase and its transition dynamics remain poorly understood. Here, a temperature control device to high-speed atomic force microscopy (HS-AFM) to observe dynamics of phase transition from ripple phase to fluid phase reversibly in real time is developed and integrated. Based on HS-AFM imaging, the phase transition processes from ripple phase to fluid phase and from ripple phase to metastable ripple phase to fluid phase could be reversibly, phenomenologically, and quantitatively studied. The results here show phase transition hysteresis in fast cooling and heating processes, while both melting and condensation occur at 24.15 °C in quasi-steady state situation. A second metastable ripple phase with larger periodicity is formed at the ripple phase to fluid phase transition when the buffer contains Ca 2+ . The presented temperature-controlled HS-AFM is a new unique experimental system to observe dynamics of temperature-sensitive processes at the nanoscopic level. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Transit Timing Observations from Kepler: IV. Confirmation of 4 Multiple Planet Systems by Simple Physical Models

    Energy Technology Data Exchange (ETDEWEB)

    Fabrycky, Daniel C.; /UC, Santa Cruz; Ford, Eric B.; /Florida U.; Steffen, Jason H.; /Fermilab; Rowe, Jason F.; /SETI Inst., Mtn. View /NASA, Ames; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Moorhead, Althea V.; /Florida U.; Batalha, Natalie M.; /San Jose State U.; Borucki, William J.; /NASA, Ames; Bryson, Steve; /NASA, Ames; Buchhave, Lars A.; /Bohr Inst. /Copenhagen U.; Christiansen, Jessie L.; /SETI Inst., Mtn. View /NASA, Ames /Caltech

    2012-01-01

    Eighty planetary systems of two or more planets are known to orbit stars other than the Sun. For most, the data can be sufficiently explained by non-interacting Keplerian orbits, so the dynamical interactions of these systems have not been observed. Here we present 4 sets of lightcurves from the Kepler spacecraft, which each show multiple planets transiting the same star. Departure of the timing of these transits from strict periodicity indicates the planets are perturbing each other: the observed timing variations match the forcing frequency of the other planet. This confirms that these objects are in the same system. Next we limit their masses to the planetary regime by requiring the system remain stable for astronomical timescales. Finally, we report dynamical fits to the transit times, yielding possible values for the planets masses and eccentricities. As the timespan of timing data increases, dynamical fits may allow detailed constraints on the systems architectures, even in cases for which high-precision Doppler follow-up is impractical.

  5. Markov transition probability-based network from time series for characterizing experimental two-phase flow

    International Nuclear Information System (INIS)

    Gao Zhong-Ke; Hu Li-Dan; Jin Ning-De

    2013-01-01

    We generate a directed weighted complex network by a method based on Markov transition probability to represent an experimental two-phase flow. We first systematically carry out gas—liquid two-phase flow experiments for measuring the time series of flow signals. Then we construct directed weighted complex networks from various time series in terms of a network generation method based on Markov transition probability. We find that the generated network inherits the main features of the time series in the network structure. In particular, the networks from time series with different dynamics exhibit distinct topological properties. Finally, we construct two-phase flow directed weighted networks from experimental signals and associate the dynamic behavior of gas-liquid two-phase flow with the topological statistics of the generated networks. The results suggest that the topological statistics of two-phase flow networks allow quantitative characterization of the dynamic flow behavior in the transitions among different gas—liquid flow patterns. (general)

  6. Transition into daylight saving time influences the fragmentation of the rest-activity cycle

    Directory of Open Access Journals (Sweden)

    Tuulio-Henriksson Annamari

    2006-01-01

    Full Text Available Abstract Background Daylight saving time is widely adopted. Little is known about its influence on the daily rest-activity cycles. We decided to explore the effects of transition into daylight saving time on the circadian rhythm of activity. Methods We monitored the rest-activity cycles with the use of wrist-worn accelerometer on a sample of ten healthy adults for ten days around the transition into summer time. Identical protocols were carried out on the same individuals in two consecutive years, yielding data on 200 person-days for analysis in this study. Results There was no significant effect on the rest-activity cycle in the sample as a whole. Fragmentation of the rest-activity cycle was enhanced in a subgroup of persons having sleep for eight hours or less (P = 0.04 but reduced in those who preferred to sleep for more than eight hours per night (P = 0.05. The average level of motor activity was increased in persons having the morning preference for daily activity patterns (P = 0.01. Conclusion Transition into daylight saving time may have a disruptive effect on the rest-activity cycle in those healthy adults who are short-sleepers or more of the evening type.

  7. Time dependency of local cerebral blood flow measurements caused by regional variations in tissue transit time

    International Nuclear Information System (INIS)

    Lear, J.L.; Kasliwal, R.; Feyerabend, A.

    1990-01-01

    Calculated values of local cerebral blood flow (LCBF) using the diffusible tracer model are assumed to be independent of time as long as experiments are brief enough to prevent tissue saturation. This paper investigates the effects of CTT variation on LCBF measurements. Using double-label quantitative digital autoradiography, we compared iodoantipyrine (IAP)-based LCBF measurements obtained with tracer infusions of different lengths of time. Lightly anesthetized rats were given simultaneous ramp infusions of C-14 IAP (45 seconds) and I-123 IAP (15 seconds) and immediately sacrificed. Two autoradiograms of each brain section, one representing I-123 and the other representing C-14, were produced, digitized, and converted into images of LCBF based on the 15- and 45-second infusion periods. The LCBF image pairs were compared on a pixel-by-pixel basis

  8. Non-adiabatic transition of the fissioning nucleus at scission: the time scale

    International Nuclear Information System (INIS)

    Carjan, N.; Rizea, M.

    2012-01-01

    The sudden approximation has been recently used to calculate the microscopic scission-properties during low-energy fission of 236 U. In this approach the scission process, i.e., the transition from two fragments connected by a thin neck to two separated fragments was considered to happen suddenly. The approach is stationary (the time evolution is not explicitly treated) and it only involves the two sets of neutron eigenstates for the two nuclear configurations considered: just before scission (α i ) and immediately after scission (α f ). The purpose of the present paper is to go beyond this mathematical approximation considering the real physical situation in which the above mentioned transition takes place in a time interval ΔT ≠ 0. For this we need to follow the evolution from α i to αf of all occupied neutron states by solving numerically the two-dimensional time-dependent Schroedinger equation with time-dependent potential. Calculations are performed for mass divisions from A L = 70 to A L = 118 (A L being the light fragment mass) taking into account all the neutron states (Ω = 1/2, 3/2,..., 11/2) that are bound in 236 U at α i . The diabatic-dissipative dynamics of the neck rupture is very complicated and its exact duration is un-known. ΔT is therefore taken as parameter having values from 0.25 x 10 -22 to 6 x 10 -22 sec. The resulting scission neutron multiplicities - sc and primary fragments' excitation energies E sc * are compared with those obtained in the frame of the sudden approximation (that corresponds to ΔT = 0). As expected, shorter is the transition time more excited are the fragments and more neutrons are emitted, the sudden approximation being an upper limit. For ΔT = 10 -22 sec, which is a realistic value, the time dependent results are 20% below this limit. For transition times longer than 5 x 10 -22 sec the adiabatic limit is reached: no scission neutrons are emitted anymore and the excitation energy at α f is negligible. The

  9. Time evolution and dynamical phase transitions at a critical time in a system of one-dimensional bosons after a quantum quench.

    Science.gov (United States)

    Mitra, Aditi

    2012-12-28

    A renormalization group approach is used to show that a one-dimensional system of bosons subject to a lattice quench exhibits a finite-time dynamical phase transition where an order parameter within a light cone increases as a nonanalytic function of time after a critical time. Such a transition is also found for a simultaneous lattice and interaction quench where the effective scaling dimension of the lattice becomes time dependent, crucially affecting the time evolution of the system. Explicit results are presented for the time evolution of the boson interaction parameter and the order parameter for the dynamical transition as well as for more general quenches.

  10. Wigner time-delay distribution in chaotic cavities and freezing transition.

    Science.gov (United States)

    Texier, Christophe; Majumdar, Satya N

    2013-06-21

    Using the joint distribution for proper time delays of a chaotic cavity derived by Brouwer, Frahm, and Beenakker [Phys. Rev. Lett. 78, 4737 (1997)], we obtain, in the limit of the large number of channels N, the large deviation function for the distribution of the Wigner time delay (the sum of proper times) by a Coulomb gas method. We show that the existence of a power law tail originates from narrow resonance contributions, related to a (second order) freezing transition in the Coulomb gas.

  11. The transition between monostable and bistable states induced by time delay in intracellular calcium oscillation

    International Nuclear Information System (INIS)

    Duan, Wei-Long

    2013-01-01

    The revised role of the time delay of active processes with colored noises of transmission of intracellular Ca 2+ in intracellular calcium oscillation (ICO) is investigated by means of a first-order algorithm based on stochastic simulation. The simulation results indicate that time delay induces a double critical phenomenon and a transition between the monostable and bistable states of the ICO system. In addition, as the time delay increases, for a cytosolic Ca 2+ concentration with weak colored noises there appears a calcium burst, and the Ca 2+ concentration of the calcium store shows nonmonotonic variation. (paper)

  12. A transit-time flow meter for measuring milliliter per minute liquid flow

    DEFF Research Database (Denmark)

    Yang, Canqian; Kymmel, Mogens; Søeberg, Henrik

    1988-01-01

    A transit-time flow meter, using periodic temperature fluctuations as tracers, has been developed for measuring liquid flow as small as 0.1 ml/min in microchannels. By injecting square waves of heat into the liquid flow upstream with a tiny resistance wire heater, periodic temperature fluctuation....... This flow meter will be used to measure and control the small liquid flow in microchannels in flow injection analysis. Review of Scientific Instruments is copyrighted by The American Institute of Physics....... are generated downstream. The fundamental frequency phase shift of the temperature signal with respect to the square wave is found to be a linear function of the reciprocal mean velocity of the fluid. The transit-time principle enables the flow meter to have high accuracy, better than 0.2%, and good linearity...

  13. Pulmonary blood volume and transit time in cirrhosis: relation to lung function

    DEFF Research Database (Denmark)

    Møller, Søren; Burchardt, H; Øgard, CG

    2006-01-01

    BACKGROUND/AIMS: In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has...... in cirrhosis. The relation between PBV and PTT and the low diffusing capacity suggests the pulmonary vascular compartment as an important element in the pathophysiology of the lung dysfunction in cirrhosis....... not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls. METHODS: Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis...

  14. Measuring the diameter of rising gas bubbles by means of the ultrasound transit time technique

    Energy Technology Data Exchange (ETDEWEB)

    Richter, T., E-mail: Thomas.Richter6@tu-dresden.de; Eckert, K., E-mail: Kerstin.Eckert@tu-dresden.de; Yang, X.; Odenbach, S.

    2015-09-15

    Highlights: • Ultrasound transit time technique (UTTT) is applied to the zig-zag raise of gas bubble. • Comparison of bubble diameter and tilt, measured by UTTT, with high-speed imaging. • Uncertainty in the determination of the bubble diameter by UTTT is less than 7%. • UTTT is able to measure dynamic changes in bubble size in opaque liquids and vessels. • UTTT can be applied to liquid metal loops. - Abstract: This study presents ultrasound transit time technique (UTTT) measurements of the diameter variations of single argon bubbles rising in a zig-zag trajectory in water. Simultaneous size measurements with a high-speed camera show that UTTT resolves both the apparent diameter and the tilt of the bubble axis with an accuracy of better than 7%. This qualifies UTTT for the measurement of bubble sizes in opaque liquids, such as liquid metals, or vessels.

  15. The Use of Stable Isotope Tracers to Quantify the Transit Time Distribution of Water

    Science.gov (United States)

    Gray, T. M.; Troch, P. A. A.

    2016-12-01

    Water pollution is an important societal problem because it can have harmful effects on human and ecological health. In order to improve water quality, scientists must develop land management methods that can avoid or mitigate environmental pollution. State of the art tools to develop such methods are flow and transport models that trace water and other solutes through the landscape. These models deliver important information that can lead to remediation efforts, and improve the quality of water for humans, plants, and animals. However, these models may be difficult to apply since many details about the catchment may not be available. Instead, a lumped approach is often used to find the water transit time using stable isotope tracers such as 18O and 2H that are naturally applied by precipitation to a catchment. The transit time distribution of water is an important indicator for the amount of solutes soil water and groundwater can contain, and thus a predictor of water quality. We conducted a 2-week long experiment using a tilted weighing lysimeter at Biosphere 2 to observe the breakthrough curves of deuterium and specific artificial DNA particles. We show that hydrological parameters can be computed in order to provide an estimate for the transit time distribution of deuterium. The convolution integral is then used to determine the distribution of the water transit time in the system. Unfortunately, stable isotopes such as deuterium make it difficult to pinpoint a specific flowpath since they naturally occur in the environment. Recent studies have shown that DNA tracers are able to trace water through the landscape. We found that DNA has a similar breakthrough curve happening at similar timescales as the deuterium. Therefore, DNA tracers may be able to identify sources of nonpoint source pollution in the future.

  16. Transit time magnetic pumping experiments in the proto-cleo stellarator

    International Nuclear Information System (INIS)

    Millar, W.

    1975-04-01

    Experiments are described in which magnetic field perturbations at frequencies approximately 100 kHz, of the type required for Transit Time Magnetic Pumping, are applied to the PROTO-CLEO stellarator. The chief effect is an increase in the plasma loss rate, which is investigated in some detail. The importance of electrostatic fields is discussed, and attention is drawn to the possibility of operating in a region not explored here, with long wavelength and low frequency. (author)

  17. H/L transition time estimation in JET using conformal predictors

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, S., E-mail: sergio.gonzalez@ciemat.es [Asociacion EURATOM/CIEMAT para Fusion, Madrid 28040 (Spain); Vega, J. [Asociacion EURATOM/CIEMAT para Fusion, Madrid 28040 (Spain); Murari, A. [Consorzio RFX, Associazione EURATOM/ENEA per la Fusione, Padova 4-25127 (Italy); Pereira, A. [Asociacion EURATOM/CIEMAT para Fusion, Madrid 28040 (Spain); Dormido-Canto, S.; Ramirez, J.M. [Departamento de Informatica y Automatica, UNED, Madrid 28040 (Spain)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer H/L transitions have been predicted using H/L and L/H models. Black-Right-Pointing-Pointer Models have been built using conformal predictors to hedge the prediction with confidence and credibility measures. Black-Right-Pointing-Pointer Models have been trained using linear and radial basis function kernels. Black-Right-Pointing-Pointer Conformal measures have proven their usefulness to validate data-driven models. - Abstract: Recent advances in data mining allow the automatic recognition of physical phenomena in the databases of fusion devices without human intervention. This is important to create large databases of physical events (thereby increasing the statistical relevance) in an unattended manner. Important examples are the L/H and H/L transitions. In this contribution, a novel technique is introduced to automatically locate H/L transitions in JET by using conformal predictors. The focus is on H/L transitions because typically there is not a clear signature in the time series of the most widely available signals to recognize the change of confinement. Conformal predictors hedge their prediction by means of two parameters: confidence and credibility. The technique has been based on binary supervised classifiers to separate the samples of the respective confinement modes. Results with several underlying classifiers are presented.

  18. Gravitational waves from a supercooled electroweak phase transition and their detection with pulsar timing arrays

    Energy Technology Data Exchange (ETDEWEB)

    Kobakhidze, Archil; Lagger, Cyril; Manning, Adrian [University of Sydney, ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, Sydney, NSW (Australia); Yue, Jason [National Taiwan Normal University, Department of Physics, Taipei (China)

    2017-08-15

    We investigate the properties of a stochastic gravitational wave background produced by a first-order electroweak phase transition in the regime of extreme supercooling. We study a scenario whereby the percolation temperature that signifies the completion of the transition, T{sub p}, is as low as a few MeV (nucleosynthesis temperature), while most of the true vacuum bubbles are formed much earlier at the nucleation temperature, T{sub n} ∝ 50 GeV. This implies that the gravitational wave spectrum is mainly produced by the collisions of large bubbles and characterised by a large amplitude and a peak frequency as low as f ∝ 10{sup -9}-10{sup -7} Hz. We show that such a scenario can occur in (but not limited to) a model based on a non-linear realisation of the electroweak gauge group, so that the Higgs vacuum configuration is altered by a cubic coupling. In order to carefully quantify the evolution of the phase transition of this model over such a wide temperature range we go beyond the usual fast transition approximation, taking into account the expansion of the Universe as well as the behaviour of the nucleation probability at low temperatures. Our computation shows that there exists a range of parameters for which the gravitational wave spectrum lies at the edge between the exclusion limits of current pulsar timing array experiments and the detection band of the future Square Kilometre Array observatory. (orig.)

  19. Dynamic phase transitions in a cylindrical Ising nanowire under a time-dependent oscillating magnetic field

    International Nuclear Information System (INIS)

    Deviren, Bayram; Kantar, Ersin; Keskin, Mustafa

    2012-01-01

    The dynamic phase transitions in a cylindrical Ising nanowire system under a time-dependent oscillating external magnetic field for both ferromagnetic and antiferromagnetic interactions are investigated within the effective-field theory with correlations and the Glauber-type stochastic dynamics approach. The effective-field dynamic equations for the average longitudinal magnetizations on the surface shell and core are derived by employing the Glauber transition rates. Temperature dependence of the dynamic magnetizations, the dynamic total magnetization, the hysteresis loop areas and the dynamic correlations are investigated in order to characterize the nature (first- or second-order) of the dynamic transitions as well as the dynamic phase transition temperatures and the compensation behaviors. The system strongly affected by the surface situations. Some characteristic phenomena are found depending on the ratio of the physical parameters in the surface shell and the core. According to the values of Hamiltonian parameters, five different types of compensation behaviors in the Néel classification nomenclature exist in the system. The system also exhibits a reentrant behavior. - Highlights: ► The dynamic aspects of a cylindrical Ising nanowire are investigated in detail. ► The dynamic magnetizations, hysteresis loop areas and correlations are calculated. ► We studied both the FM and AFM interactions within the EFT with correlations. ► Some characteristic phenomena are found depending on the interaction parameters. ► We obtained five different types of compensation behaviors and reentrant behavior.

  20. Dynamic phase transitions in a cylindrical Ising nanowire under a time-dependent oscillating magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Deviren, Bayram [Department of Physics, Nevsehir University, 50300 Nevsehir (Turkey); Kantar, Ersin [Department of Physics, Erciyes University, 38039 Kayseri (Turkey); Keskin, Mustafa, E-mail: keskin@erciyes.edu.tr [Department of Physics, Erciyes University, 38039 Kayseri (Turkey)

    2012-07-15

    The dynamic phase transitions in a cylindrical Ising nanowire system under a time-dependent oscillating external magnetic field for both ferromagnetic and antiferromagnetic interactions are investigated within the effective-field theory with correlations and the Glauber-type stochastic dynamics approach. The effective-field dynamic equations for the average longitudinal magnetizations on the surface shell and core are derived by employing the Glauber transition rates. Temperature dependence of the dynamic magnetizations, the dynamic total magnetization, the hysteresis loop areas and the dynamic correlations are investigated in order to characterize the nature (first- or second-order) of the dynamic transitions as well as the dynamic phase transition temperatures and the compensation behaviors. The system strongly affected by the surface situations. Some characteristic phenomena are found depending on the ratio of the physical parameters in the surface shell and the core. According to the values of Hamiltonian parameters, five different types of compensation behaviors in the Neel classification nomenclature exist in the system. The system also exhibits a reentrant behavior. - Highlights: Black-Right-Pointing-Pointer The dynamic aspects of a cylindrical Ising nanowire are investigated in detail. Black-Right-Pointing-Pointer The dynamic magnetizations, hysteresis loop areas and correlations are calculated. Black-Right-Pointing-Pointer We studied both the FM and AFM interactions within the EFT with correlations. Black-Right-Pointing-Pointer Some characteristic phenomena are found depending on the interaction parameters. Black-Right-Pointing-Pointer We obtained five different types of compensation behaviors and reentrant behavior.

  1. Properties of transit-time interactions in magnetized plasmas: Analytic and numerical results

    International Nuclear Information System (INIS)

    Melatos, A.; Robinson, P.A.

    1993-01-01

    The recently developed perturbation theory of transit-time interactions between particles and coherent wave packets in magnetized plasmas is applied to particular field structures. Limits of validity are determined by comparison with test-particle simulations, showing that the theory is accurate everywhere except near certain well-determined resonances, for wave fields exceeding a characteristic threshold, and for particles below a particular velocity. The properties of transit-time interactions in magnetized plasmas are investigated in detail to determine their dependence on the fields and parameters of the particle motion. Resonant particle scattering is found to occur at low particle velocities when the frequency of the coherent wave packet is an integer multiple of the gyrofrequency. Two different types of resonant transit-time dissipation are also observed: one arises from transient cyclotron acceleration in the localized wave packet, the other from beating between the gyration of the particles and the oscillation of the wave packet field. Both effects involve an interplay between the field geometry and resonant oscillations

  2. Insights into the photochemical disproportionation of transition metal dimers on the picosecond time scale.

    Science.gov (United States)

    Lomont, Justin P; Nguyen, Son C; Harris, Charles B

    2013-05-09

    The reactivity of five transition metal dimers toward photochemical, in-solvent-cage disproportionation has been investigated using picosecond time-resolved infrared spectroscopy. Previous ultrafast studies on [CpW(CO)3]2 established the role of an in-cage disproportionation mechanism involving electron transfer between 17- and 19-electron radicals prior to diffusion out of the solvent cage. New results from time-resolved infrared studies reveal that the identity of the transition metal complex dictates whether the in-cage disproportionation mechanism can take place, as well as the more fundamental issue of whether 19-electron intermediates are able to form on the picosecond time scale. Significantly, the in-cage disproportionation mechanism observed previously for the tungsten dimer does not characterize the reactivity of four out of the five transition metal dimers in this study. The differences in the ability to form 19-electron intermediates are interpreted either in terms of differences in the 17/19-electron equilibrium or of differences in an energetic barrier to associative coordination of a Lewis base, whereas the case for the in-cage vs diffusive disproportionation mechanisms depends on whether the 19-electron reducing agent is genuinely characterized by 19-electron configuration at the metal center or if it is better described as an 18 + δ complex. These results help to better understand the factors that dictate mechanisms of radical disproportionation and carry implications for radical chain mechanisms.

  3. The acceleration of energetic particles in the interplanetary medium by transit time damping

    International Nuclear Information System (INIS)

    Fisk, L.A.

    1976-01-01

    It has been reported recently by McDonald et al. (1976) that 1-MeV protons may undergo considerable acceleration in corotating streams. It has been suggested recently by Fisk et al. (1974b) that interstellar neutral particles which are ionized in the solar cavity may be accelerated in the solar wind and may account for the anomalous component that is observed in low-energy cosmic rays (at approx.10 MeV/nucleon). It is shown here that the particles in both of these cases could be accelerated by transit time damping propagating fluctuations in the magnitude of the interplanetary magnetic field (e.g., magnetosonic waves). The protons in corotating streams may be accelerated by transit time damping the small-scale variations in the field magnitude that are observed at a low level in the inner solar system. The interstellar ions may be accelerated by transit time damping large-scale field variations in the outer solar system

  4. A Framework for Relating Timed Transition Systems and Preserving TCTL Model Checking

    DEFF Research Database (Denmark)

    Jacobsen, Lasse; Jacobsen, Morten; Møller, Mikael Harkjær

    2010-01-01

    Many formal translations between time dependent models have been proposed over the years. While some of them produce timed bisimilar models, others preserve only reachability or (weak) trace equivalence. We suggest a general framework for arguing when a translation preserves Timed Computation Tree...... Logic (TCTL) or its safety fragment.The framework works at the level of timed transition systems, making it independent of the modeling formalisms and applicable to many of the translations published in the literature. Finally, we present a novel translation from extended Timed-Arc Petri Nets...... to Networks of Timed Automata and using the framework argue that itpreserves the full TCTL. The translation has been implemented in the verification tool TAPAAL....

  5. Time-gated single-photon detection module with 110 ps transition time and up to 80 MHz repetition rate

    Energy Technology Data Exchange (ETDEWEB)

    Buttafava, Mauro, E-mail: mauro.buttafava@polimi.it; Boso, Gianluca; Ruggeri, Alessandro; Tosi, Alberto [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy); Dalla Mora, Alberto [Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy)

    2014-08-15

    We present the design and characterization of a complete single-photon counting module capable of time-gating a silicon single-photon avalanche diode with ON and OFF transition times down to 110 ps, at repetition rates up to 80 MHz. Thanks to this sharp temporal filtering of incoming photons, it is possible to reject undesired strong light pulses preceding (or following) the signal of interest, allowing to increase the dynamic range of optical acquisitions up to 7 decades. A complete experimental characterization of the module highlights its very flat temporal response, with a time resolution of the order of 30 ps. The instrument is fully user-configurable via a PC interface and can be easily integrated in any optical setup, thanks to its small and compact form factor.

  6. Time-gated single-photon detection module with 110 ps transition time and up to 80 MHz repetition rate

    International Nuclear Information System (INIS)

    Buttafava, Mauro; Boso, Gianluca; Ruggeri, Alessandro; Tosi, Alberto; Dalla Mora, Alberto

    2014-01-01

    We present the design and characterization of a complete single-photon counting module capable of time-gating a silicon single-photon avalanche diode with ON and OFF transition times down to 110 ps, at repetition rates up to 80 MHz. Thanks to this sharp temporal filtering of incoming photons, it is possible to reject undesired strong light pulses preceding (or following) the signal of interest, allowing to increase the dynamic range of optical acquisitions up to 7 decades. A complete experimental characterization of the module highlights its very flat temporal response, with a time resolution of the order of 30 ps. The instrument is fully user-configurable via a PC interface and can be easily integrated in any optical setup, thanks to its small and compact form factor

  7. Measurement of small bowel transit time by 99Tcm-SC imaging: preliminary clinical study

    International Nuclear Information System (INIS)

    Zhang Shaohua; Xu Jingying; Bei Lian; Zhu Chaohui; Ba Jiantao

    1999-01-01

    Objective: To develop a method of measuring small bowel transit time (SBTT) by 99 Tc m -sulfur collide (SC) imaging and to compare with the method of added lactose in the test meal. Methods: 20 healthy volunteers and 26 patients with gastrointestinal disorders were studied. In fasting state, the subjects were asked to ingest the 99 Tc m -SC labelled solid meal within 5 minutes, then the image acquisition was immediately started with SPECT. The images were acquired every 15 min during the first hour, at 30 min intervals during 2∼4 hours and hourly thereafter until 80% radioactivity had entered the colon. One week later, the same procedure of imaging with 15 g lactulose added in the test meal was performed. The regions of interest (ROIs) were taken at stomach and colon, and the SBTT was calculated by deconvolution or by subtraction of the 50% time of gastric emptying from the 50% time of colon filling. Results: 1) The mean SBTT of 20 healthy volunteers was (4.2 +- 0.5) h, oral-caecum transit time (OCTT) was (4.3 +- 0.6) h; lactulose shortened the SBTT by (1.8 +- 0.6) h; 2) 26 patients showed different results of SBTT due to their different gastrointestinal disorders bases. Conclusions: 99 Tc m -SC imaging was a noninvasive and useful method to measure SBTT. The added lactulose can shorten the examination time and help to identify the time of food to the ileocecal region

  8. Information structure and organisation in change of shift reports: An observational study of nursing hand-offs in a Paediatric Intensive Care Unit.

    Science.gov (United States)

    Foster-Hunt, Tara; Parush, Avi; Ellis, Jacqueline; Thomas, Margot; Rashotte, Judy

    2015-06-01

    Patient hand-offs involve the exchange of critical information. Ineffective hand-offs can result in reduced patient safety by leading to wrong treatment, delayed diagnoses or other outcomes that can negatively affect the healthcare system. The objectives of this study were to uncover the structure of the information conveyed during patient hand-offs and look for principles characterising the organisation of the information. With an observational study approach, data was gathered during the morning and evening nursing change of shift hand-offs in a Paediatric Intensive Care Unit. Content analysis identified a common meta-structure used for information transfer that contained categories with varying degrees of information integration and the repetition of high consequence information. Differences were found in the organisation of the hand-off structures, and these varied as a function of nursing experience. The findings are discussed in terms of the potential benefits of computerised tools which utilise standardised structure for information transfer and the implications for future education and critical care skill acquisition. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. [Evaluation and Optimization of Microvascular Arterial Anastomoses by Transit Time Flow Measurement].

    Science.gov (United States)

    Herberhold, S; Röttker, J; Bartmann, D; Solbach, A; Keiner, S; Welz, A; Bootz, F; Laffers, W

    2016-03-01

    INDRODUCTION: The regular application of transit time flow measurement in microvascular anastomoses during heart surgery has lead to improvements of the outcome of coronary artery bypass grafts. Our study was meant to discover whether this measurement method was also applicable for evaluation and optimization of microvascular arterial anastomoses of radial forearm flaps. In this prospective examination a combining ultrasound imaging and transit time flow measurement device (VeriQ, MediStim) was used during surgery to assess anastomotic quality of 15 radial forearm flaps. Pulsatility index (PI) and mean blood flow were measured immediately after opening the arterial anastomosis as well as 15 min afterwards. Furthermore, application time and description of handling were recorded seperately for every assessment. Mean blood flow immediately after opening the anastomosis and 15 min later were 3.9 and 3.4 ml/min resepectively showing no statistically significant difference (p=0.96). There was no significance in the increase of pulsatility index from 22.1 to 27.2 (p=0.09) during the same time range, either. Due to measurement results showing atypical pulse curves in 2 cases decision for surgical revision of the anastomoses was made. All forearm flaps showed good vascularisation during follow-up. Time for device set up, probe placement and measurements was about 20 min. Handling was described to be uncomplicated without exception. There were no noteworthy problems. Transit time flow measurement contributes to the improvement of anastomotic quality and therefore to the overall outcome of radial forearm flaps. The examined measurement method provides objective results and is useful for documentation purposes. © Georg Thieme Verlag KG Stuttgart · New York.

  10. Effects of skin pressure by clothing on digestion and orocecal transit time of food.

    Science.gov (United States)

    Sone, Y; Kato, N; Kojima, Y; Takasu, N; Tokura, H

    2000-05-01

    In order to reveal the influence of clothing skin pressure on digestion of food through the gastrointestinal tract, we examined the absorption of dietary carbohydrate and orocecal transit time of a test meal by means of a breath hydrogen test on 7 healthy young women. In this experiment, we collected breath samples from the participants wearing loose-fitting experimental garment on the second day of the experiment and from the same participants but wearing an additional tight-fitting girdle on the following day for 16 hours and 9 hours, respectively. Skin pressure applied by a girdle on participant's waist, abdomen and hip region was 15.5 +/- 0.4 mmHg (mean +/- SE), 11.0 +/- 0.2 mmHg, and 13.6 +/- 0.6 mmHg, respectively, and the values were 2-3 times larger than those of the experimental garment. The hydrogen concentration vs. time curve showed that breath hydrogen levels at its peaks (15:00, 15:30, 16:00, 16:30, and 17:00 hr) on the third day of the experiment were significantly higher than those of the corresponding time on the second day (p clothing condition (p hand, the transit time of the test meal for the subjects wearing a girdle did not differ significantly from that for the subjects wearing the garment of less pressure (270 +/- 18 minutes and 263 +/- 21 minutes, respectively). These results indicate that the clothing skin pressure has an inhibitory effect on the absorption of dietary carbohydrate in the small intestine, but no effect on the orocecal transit time of a meal.

  11. Colon Transit Time Test in Korean Children with Chronic Functional Constipation

    Science.gov (United States)

    Yoo, Ha Yeong; Kim, Mock Ryeon; Park, Hye Won; Son, Jae Sung

    2016-01-01

    Purpose Each ethnic group has a unique life style, including diets. Life style affects bowel movement. The aim of this study is to describe the results of colon transit time (CTT) tests in Korean children who had chronic functional constipation based on highly refined data. Methods One hundred ninety (86 males) out of 415 children who performed a CTT test under the diagnosis of chronic constipation according to Rome III criteria at Konkuk University Medical Center from January 2006 through March 2015 were enrolled in this study. Two hundreds twenty-five children were excluded on the basis of CTT test result, defecation diary, and clinical setting. Shapiro-Wilk and Mann-Whitney U, and chi-square tests were used for statistical analysis. Results The median value and interquartile range (IQR) of CTT was 54 (37.5) hours in Encopresis group, and those in non-encopresis group was 40.2 (27.9) hours (pencopresis group and encopresis was statistically significant (p=0.002). The non-encopresis group (n=154, 81.1%) was divided into normal transit subgroup (n=84, 54.5%; median value and IQR of CTT=26.4 [9.6] hours), outlet obstruction subgroup (n=18, 11.7%; 62.4 [15.6] hours), and slow transit subgroup (n=52, 33.8%; 54.6 [21.0] hours]. The encopresis group (n=36, 18.9%) was divided into normal transit subgroup (n=8, 22.2%; median value and IQR of CTT=32.4 [9.9] hours), outlet obstruction subgroup (n=8, 22.2%; 67.8 [34.8] hours), and slow transit subgroup (n=20, 55.6%; 59.4 [62.7]hours). Conclusion This study provided the basic pattern and value of the CTT test in Korean children with chronic constipation. PMID:27064388

  12. Time-dependent Hartree-Fock dynamics and phase transition in Lipkin-Meshkov-Glick model

    International Nuclear Information System (INIS)

    Kan, K.; Lichtner, P.C.; Dworzecka, M.; Griffin, J.J.

    1980-01-01

    The time-dependent Hartree-Fock solutions of the two-level Lipkin-Meshkov-Glick model are studied by transforming the time-dependent Hartree-Fock equations into Hamilton's canonical form and analyzing the qualitative structure of the Hartree-Fock energy surface in the phase space. It is shown that as the interaction strength increases these time-dependent Hartree-Fock solutions undergo a qualitative change associated with the ground state phase transition previously studied in terms of coherent states. For two-body interactions stronger than the critical value, two types of time-dependent Hartree-Fock solutions (the ''librations'' and ''rotations'' in Hamilton's mechanics) exist simultaneously, while for weaker interactions only the rotations persist. It is also shown that the coherent states with the maximum total pseudospin value are determinants, so that time-dependent Hartree-Fock analysis is equivalent to the coherent state method

  13. Achievable Throughput-Based MAC Layer Handoff in IEEE 802.11 Wireless Local Area Networks

    Directory of Open Access Journals (Sweden)

    Wu Haitao

    2009-01-01

    Full Text Available We propose a MAC layer handoff mechanism for IEEE 802.11 Wireless Local Area Networks (WLAN to give benefit to bandwidth-greedy applications at STAs. The proposed mechanism determines an optimal AP with the maximum achievable throughput rather than the best signal condition by estimating the AP's bandwidth with a new on-the-fly measurement method, Transient Frame Capture (TFC, and predicting the actual throughput could be achieved at STAs. Since the TFC is employed based on the promiscuous mode of WLAN NIC, STAs can avoid the service degradation through the current associated AP. In addition, the proposed mechanism is a client-only solution which does not require any modification of network protocol on APs. To evaluate the performance of the proposed mechanism, we develop an analytic model to estimate reliable and accurate bandwidth of the AP and demonstrate through testbed measurement with various experimental study methods. We also validate the fairness of the proposed mechanism through simulation studies.

  14. Assessment of the Variation Associated with Repeated Measurement of Gastrointestinal Transit Times and Assessment of the Effect of Oral Ranitidine on Gastrointestinal Transit Times Using a Wireless Motility Capsule System in Dogs

    Directory of Open Access Journals (Sweden)

    Jonathan A. Lidbury

    2012-01-01

    Full Text Available This study aimed to evaluate the variation associated with repeated measurement of gastrointestinal (GI transit times and the effect of oral ranitidine on GI transit times in healthy dogs using a wireless motility capsule (WMC system. Eight privately owned healthy adult dogs were enrolled, and one developed diarrhea and was removed from the study. For the first 3 repetitions, each dog was fed a standard meal followed by oral administration of a WMC. For the 4th repetition, each dog was given ranitidine hydrochloride (75 mg PO every 12 hours prior to and during assessment of GI transit times. Mean between-subject coefficients of variation for gastric emptying time (GET, small and large bowel transit time (SLBTT, and total transit time (TTT were 26.9%, 32.3%, and 19.6%, respectively. Mean within-subject coefficients of variation for GET, SLBTT, and TTT were 9.3%, 19.6%, and 15.9%, respectively. Median GET, SLBTT, and TTT without ranitidine were 719, 1,636, and 2,735 minutes, respectively. Median GET, SLBTT, and TTT with ranitidine were 757, 1,227, and 2,083 minutes, respectively. No significant differences in GI transit times were found between any of the 4 repetitions. Under these experimental conditions, no significant effects of oral ranitidine on GI transit times were observed.

  15. Mean transit times as a parameter for optimizing the quantitative brain scintigraphy

    International Nuclear Information System (INIS)

    Vosberg, H.; Szabo, Z.; Nase, D.; Feinendegen, L.E.

    1984-01-01

    Cerebral perfusion imaging with non-diffusible Tc-9mm-labelled substances is a simple screening procedure for identifying perfusion deficits, which can easily be applied in all nuclear medicine departments. Gross hypoperfusion can readily be recognized on analog images. To visualize and assess minor changes in limited brain areas, the perfusion phase in each pixel was fitted to a gamma function and the mean transit times were stored as parametric matrix. To examine the diagnostic sensitivity of transit time images versus that of the usual semiquantitative procedures, data of 84 patients with unilateral cerebral blood flow disorders were analyzed. From the pertinent studies parameters of hemispheral flow were computed using 10 different methodes. Data for the normal and the diseased hemisphere and their ratios were subjected to analysis of variance to assess their diagnostic weight. Patient groups with different angiologically verfied stenoses or occlusion were most easily dinstinguished by the time interval carotid artery - hemispheral peak. The values derived from the parametric images of mean transit times showed more or less the same weight, but the special advantage offered by parametric images, i.e. the precise visualization of the hypoperfused area, was not considered in the analysis of variance. Factorial analysis indicated that the parameters examined can be described by 2 factors to the extent of 72%. The first of these factors combines the weights (58%) of those variables which, in one may or the other, reflect the time of perfusion, while the second includes variables which make use of the count rates for differentiation (14%). The analysis of gamma camera data for diagnosing cerebral blood flow disorders is thus improved. (Author)

  16. Television viewing, leisure-time exercise and acute coronary syndrome in transitional Albania.

    Science.gov (United States)

    Burazeri, Genc; Goda, Artan; Kark, Jeremy D

    2008-07-01

    To assess the association of leisure-time exercise and television (TV) viewing, a sedentary marker, with acute coronary syndrome (ACS) in Albania, a transitional country in Southeast Europe. A population-based case-control study was conducted among Tirana residents in 2003-2006. Information on leisure-time exercise (transformed into kilocalories of energy expenditure) and daily hours of TV viewing was obtained by interviewer-administered questionnaire. 460 non-fatal ACS patients (368 men, 92 women) and 628 coronary heart disease-free controls (413 men, 215 women) were studied. Adjusted for socio-demographic characteristics, conventional coronary risk factors and leisure-time exercise, TV viewing was associated with ACS in women (OR=1.66, 95%CI=1.12-2.46 per hour/day viewing), but not in men (OR=0.93, 95%CI=0.81-1.07; P for sex-interaction=0.02). A low level of leisure-time exercise (adjusted also for TV viewing) was associated with ACS similarly in men and women (pooled sexes OR=2.03, 95%CI=1.29-3.22 for bottom vs top tertile of energy expenditure). Leisure-time inactivity is confirmed as an important risk factor for ACS also in Southeastern Europe. TV viewing may be an informative coronary risk marker in transitional societies, especially in women.

  17. Identifying timescales and possible precursors of the awake to asleep transition in EOG time series

    International Nuclear Information System (INIS)

    Carniel, Roberto; Del Pin, Enrico; Budai, Riccardo; Pascolo, Paolo

    2005-01-01

    In this work we study the awake to asleep state transition in eye blinking activity. In this perspective the human electroculographic activity (EOG) was first experimentally investigated by means of a spectral analyses of the time series resulting for processes underlying both the brain activity and the eye dynamics. We studied the evolution of the spectral content both via the classical spectrogram and with the computation of summarizing scalar parameters: mean frequency, maximum frequency, spectral variance. With these tools we highlighted a significative dynamical change appearing before the transition from the awake to the asleep state, characterized by a general widening of the spectrum, that translates into a decrease of the maximum frequency, an increase of the average frequency and an increase of the spectral variance. Due to inherently high non-linearities involved, chaotic patterns were likely to occur in the experimental time series. These were analyzed therefore with the chaos theory. In particular we studied the time evolution of dynamical parameters as computed on different windows of the time series, i.e. optimal delay time as suggested by autocorrelation and mutual information on one side, embedding quality evaluation as suggested by the False Nearest Neighbours percentage on the other

  18. Correlations between aorto-popliteal bolus transit speed and aortic and popliteal bolus transit time during CT angiography of aortoiliac and lower extremity arteries

    Energy Technology Data Exchange (ETDEWEB)

    Nakaya, Yasuhiro, E-mail: y-nakaya@radiol.med.osaka-u.ac.jp [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita City, Osaka 565-0871 (Japan); Kim, Tonsok; Hori, Masatoshi; Onishi, Hiromitsu; Nakamoto, Atsushi; Tsuboyama, Takahiro; Maeda, Noboru; Higashihara, Hiroki; Tomoda, Kaname; Nakamura, Hironobu [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita City, Osaka 565-0871 (Japan)

    2011-08-15

    Purpose: The purpose of this study was to investigate correlations between the aorto-popliteal bolus transit speed and aortic and popliteal bolus transit time in order to evaluate the possibility for prediction of bolus transit speed by single test injection technique. Materials and methods: Approval was obtained from our institutional review board for this study, which included 42 patients, from all of whom written informed consent was obtained. Low-dose serial CT scanning after injection of 12 ml contrast material (300 mg/ml) at a rate of 3 ml/s followed by saline flush was performed twice, first at the level of the upper abdomen and second at the level of the knee joint. The times needed to reach peak enhancement of the upper abdominal aorta (T-aorta) and bilateral popliteal arteries (T-popliteal) were obtained, and aorto-popliteal bolus transit speeds between the abdominal aorta and popliteal arteries were calculated. ABI was recorded for the bilateral feet. The Pearson's product-moment correlation coefficient was used to investigate the correlation between the bolus transit speed and T-aorta, T-popliteal, ABI, and patient age. Result: The respective correlation coefficients for bolus transit speed on the one hand and T-aorta, T-popliteal, ABI, patient age on the other were -0.50, -0.84, 0.36, and -0.52. Conclusion: The time to peak enhancement for popliteal arteries showed the strongest correlation with aorto-popliteal bolus transit speeds, and was considered to be the most accurate predictor for aorto-popliteal bolus transit speeds.

  19. Does timing and sequencing of transitions to adulthood make a difference? Stress, smoking, and physical activity among young Australian women.

    Science.gov (United States)

    Bell, Sandra; Lee, Christina

    2006-01-01

    The major changes of the transition to adulthood are argued to be stressful, and health-related behaviors such as smoking and physical activity may be adopted, consolidated, or abandoned at this time. On the other hand, research has suggested that the normative transitions of emerging adulthood, although involving considerable change, may be associated with low stress because they are perceived as both positive and normal at this life stage. This article examines relations between the timing and sequencing of life transitions and stress and health-related behaviors, focusing on the transition to young adulthood among Australian women. A total of 853 women aged 22 to 27 provided information about the timing and sequencing of 6 life transitions: moving out of home, stopping full-time education, starting full-time work, having the first live-in relationship, marriage, and motherhood-and stress, smoking, and physical activity. Most had moved out of home, stopped full-time education, and started full-time work, but only 14% had undertaken all 6 transitions. Overall, 70% of participants had made transitions "in order." Overall, the findings suggest that the relations between timing and sequencing of transitions, and indicators of health, are moderate for smoking, but small for stress and for physical activity. These effects remained after controlling for socioeconomic status of the participants' families of origin. Matching current social norms for the timing and sequencing of life changes may be of less importance for women's well-being than is commonly believed. Although the significant relations between early or "out of order" transitions and smoking are of concern, the smaller relations with stress and with sedentariness suggest that such transitions may have limited negative consequences, and support the view that individuals are active in choosing the life path that is appropriate for them and their circumstances.

  20. A Fourier Collocation Approach for Transit-Time Ultrasonic Flowmeter Under Multi-Phase Flow Conditions

    DEFF Research Database (Denmark)

    Simurda, Matej; Lassen, Benny; Duggen, Lars

    2017-01-01

    A numerical model for a clamp-on transit-time ultrasonic flowmeter (TTUF) under multi-phase flow conditions is presented. The method solves equations of linear elasticity for isotropic heterogeneous materials with background flow where acoustic media are modeled by setting shear modulus to zero....... Spatial derivatives are calculated by a Fourier collocation method allowing the use of the fast Fourier transform (FFT) and time derivatives are approximated by a finite difference (FD) scheme. This approach is sometimes referred to as a pseudospectral time-domain method. Perfectly matched layers (PML......) are used to avoid wave-wrapping and staggered grids are implemented to improve stability and efficiency. The method is verified against exact analytical solutions and the effect of the time-staggering and associated lowest number of points per minimum wavelengths value is discussed. The method...

  1. Comparing Transition-Edge Sensor Response Times in a Modified Contact Scheme with Different Support Beams

    Science.gov (United States)

    Beyer, A. D.; Kenyon, M. E.; Bumble, B.; Runyan, M. C.; Echternach, P. E.; Holmes, W. A.; Bock, J. J.; Bradford, C. M.

    2013-01-01

    We present measurements of the thermal conductance, G, and effective time constants, tau, of three transition-edge sensors (TESs) populated in arrays operated from 80-87mK with T(sub C) approximately 120mK. Our TES arrays include several variations of thermal architecture enabling determination of the architecture that demonstrates the minimum noise equivalent power (NEP), the lowest tau and the trade-offs among designs. The three TESs we report here have identical Mo/Cu bilayer thermistors and wiring structures, while the thermal architectures are: 1) a TES with straight support beams of 1mm length, 2) a TES with meander support beams of total length 2mm and with 2 phononfilter blocks per beam, and 3) a TES with meander support beams of total length 2mm and with 6 phonon-filter blocks per beam. Our wiring scheme aims to lower the thermistor normal state resistance R(sub N) and increase the sharpness of the transition alpha=dlogR/dlogT at the transition temperature T(sub C). We find an upper limit of given by (25+/-10), and G values of 200fW/K for 1), 15fW/K for 2), and 10fW/K for 3). The value of alpha can be improved by slightly increasing the length of our thermistors.

  2. Regional Gastrointestinal Transit Times in Patients With Carcinoid Diarrhea: Assessment With the Novel 3D-Transit System

    DEFF Research Database (Denmark)

    Gregersen, Tine; Haase, Anne-Mette; Schlageter, Vincent

    2015-01-01

    BACKGROUND/AIMS: The paucity of knowledge regarding gastrointestinal motility in patients with neuroendocrine tumors and carcinoid diarrhea re-stricts targeted treatment. 3D-Transit is a novel, minimally invasive, ambulatory method for description of gastrointestinal motility. The system has not ...

  3. How does landscape structure influence catchment transit time across different geomorphic provinces?

    Science.gov (United States)

    Tetzlaff, D.; Seibert, J.; McGuire, K.J.; Laudon, H.; Burns, Douglas A.; Dunn, S.M.; Soulsby, C.

    2009-01-01

    Despite an increasing number of empirical investigations of catchment transit times (TTs), virtually all are based on individual catchments and there are few attempts to synthesize understanding across different geographical regions. Uniquely, this paper examines data from 55 catchments in five geomorphic provinces in northern temperate regions (Scotland, United States of America and Sweden). The objective is to understand how the role of catchment topography as a control on the TTs differs in contrasting geographical settings. Catchment inverse transit time proxies (ITTPs) were inferred by a simple metric of isotopic tracer damping, using the ratio of standard deviation of ??18O in streamwater to the standard deviation of ??18O in precipitation. Quantitative landscape analysis was undertaken to characterize the catchments according to hydrologically relevant topographic indices that could be readily determined from a digital terrain model (DTM). The nature of topographic controls on transit times varied markedly in different geomorphic regions. In steeper montane regions, there are stronger gravitational influences on hydraulic gradients and TTs tend to be lower in the steepest catchments. In provinces where terrain is more subdued, direct topographic control weakened; in particular, where flatter areas with less permeable soils give rise to overland flow and lower TTs. The steeper slopes within this flatter terrain appear to have a greater coverage of freely draining soils, which increase sub-surface flow, therefore increasing TTs. Quantitative landscape analysis proved a useful tool for intercatchment comparison. However, the critical influence of sub-surface permeability and connectivity may limit the transferability of predictive tools of hydrological function based on topographic parameters alone. Copyright ?? 2009 John Wiley & Sons, Ltd.

  4. Characterisation of two-phase horizontal flow regime transition by the application of time-frequency analysis methods

    International Nuclear Information System (INIS)

    Seleghim, Paulo

    1996-01-01

    This work concerns the development of a methodology which objective is to characterize and diagnose two-phase flow regime transitions. The approach is based on the fundamental assumption that a transition flow is less stationary than a flow with an established regime. In a first time, the efforts focused on: 1) the design and construction of an experimental loop, allowing to reproduce the main horizontal two-phase flow patterns, in a stable and controlled way, 2) the design and construction of an electrical impedance probe, providing an imaged information of the spatial phase distribution in the pipe, the systematic study of the joint time-frequency and time-scale analysis methods, which permitted to define an adequate parameter quantifying the un-stationary degree. In a second time, in order to verify the fundamental assumption, a series of experiments were conducted, which objective was to demonstrate the correlation between un-stationary and regime transition. The un-stationary degree was quantified by calculating the Gabor's transform time-frequency covariance of the impedance probe signals. Furthermore, the phenomenology of each transition was characterized by the joint moments and entropy. The results clearly show that the regime transitions are correlated with local-time frequency covariance peaks, which demonstrates that these regime transitions are characterized by a loss of stationarity. Consequently, the time-frequency covariance constitutes an objective two-phase flow regime transition indicator. (author) [fr

  5. A deconvolution method for deriving the transit time spectrum for ultrasound propagation through cancellous bone replica models.

    Science.gov (United States)

    Langton, Christian M; Wille, Marie-Luise; Flegg, Mark B

    2014-04-01

    The acceptance of broadband ultrasound attenuation for the assessment of osteoporosis suffers from a limited understanding of ultrasound wave propagation through cancellous bone. It has recently been proposed that the ultrasound wave propagation can be described by a concept of parallel sonic rays. This concept approximates the detected transmission signal to be the superposition of all sonic rays that travel directly from transmitting to receiving transducer. The transit time of each ray is defined by the proportion of bone and marrow propagated. An ultrasound transit time spectrum describes the proportion of sonic rays having a particular transit time, effectively describing lateral inhomogeneity of transit times over the surface of the receiving ultrasound transducer. The aim of this study was to provide a proof of concept that a transit time spectrum may be derived from digital deconvolution of input and output ultrasound signals. We have applied the active-set method deconvolution algorithm to determine the ultrasound transit time spectra in the three orthogonal directions of four cancellous bone replica samples and have compared experimental data with the prediction from the computer simulation. The agreement between experimental and predicted ultrasound transit time spectrum analyses derived from Bland-Altman analysis ranged from 92% to 99%, thereby supporting the concept of parallel sonic rays for ultrasound propagation in cancellous bone. In addition to further validation of the parallel sonic ray concept, this technique offers the opportunity to consider quantitative characterisation of the material and structural properties of cancellous bone, not previously available utilising ultrasound.

  6. Effect of Epidural Block under General Anesthesia on Pulse Transit Time

    International Nuclear Information System (INIS)

    Choi, Byeong Cheol; Kim, Seong Min; Jung, Dong Keun; Kim, Gi Ryon; Lee, He Jeong; Jeon, Gye Rock

    2005-01-01

    Epidural block under general anesthesia has been widely used to control postoperative pain. In this anesthetic state many hemodynamic parameters are changed. Moreover pulse transit time is influenced by this memodynamic change. PPT change in the finger and the toe due to relaxation of arterial wall muscle after general anesthesia and epidural block under general anesthesia. This study, in the both general anesthesia and epidural block under general anesthesia, ΔPTT of the toe and of the finger are measured. In addition, ΔPTT(toe-finger) of the epidural block under general anesthesia and of the general anesthesia were compared

  7. GARUSO - Version 1.0. Uncertainty model for multipath ultrasonic transit time gas flow meters

    Energy Technology Data Exchange (ETDEWEB)

    Lunde, Per; Froeysa, Kjell-Eivind; Vestrheim, Magne

    1997-09-01

    This report describes an uncertainty model for ultrasonic transit time gas flow meters configured with parallel chords, and a PC program, GARUSO Version 1.0, implemented for calculation of the meter`s relative expanded uncertainty. The program, which is based on the theoretical uncertainty model, is used to carry out a simplified and limited uncertainty analysis for a 12`` 4-path meter, where examples of input and output uncertainties are given. The model predicts a relative expanded uncertainty for the meter at a level which further justifies today`s increasing tendency to use this type of instruments for fiscal metering of natural gas. 52 refs., 15 figs., 11 tabs.

  8. Predicting critical transitions in dynamical systems from time series using nonstationary probability density modeling.

    Science.gov (United States)

    Kwasniok, Frank

    2013-11-01

    A time series analysis method for predicting the probability density of a dynamical system is proposed. A nonstationary parametric model of the probability density is estimated from data within a maximum likelihood framework and then extrapolated to forecast the future probability density and explore the system for critical transitions or tipping points. A full systematic account of parameter uncertainty is taken. The technique is generic, independent of the underlying dynamics of the system. The method is verified on simulated data and then applied to prediction of Arctic sea-ice extent.

  9. On some practical consideration of the electron beam breakup transit time oscillator

    International Nuclear Information System (INIS)

    Kwan, T.J.T.

    1992-01-01

    The electron beam breakup transit time oscillator (BTO) makes use of the interaction between an electron beam and the azimuthally azimuthally asymmetric transverse magnetic mode (TM 110 ) of a cavity to facilitate the exchange of energy between them. Linear theory has shown a large growth rate in the regime where space-charge effects can be ignored. In this study, we have investigated the non-ideal elements in the BTO and evaluated their effects accordingly. The practical issues under consideration are electron beam quality, energy, and space-charge potential. Our calculations indicate only a modest unfavorable scalings with respect to these parameters

  10. Smartphone-based Continuous Blood Pressure Measurement Using Pulse Transit Time.

    Science.gov (United States)

    Gholamhosseini, Hamid; Meintjes, Andries; Baig, Mirza; Linden, Maria

    2016-01-01

    The increasing availability of low cost and easy to use personalized medical monitoring devices has opened the door for new and innovative methods of health monitoring to emerge. Cuff-less and continuous methods of measuring blood pressure are particularly attractive as blood pressure is one of the most important measurements of long term cardiovascular health. Current methods of noninvasive blood pressure measurement are based on inflation and deflation of a cuff with some effects on arteries where blood pressure is being measured. This inflation can also cause patient discomfort and alter the measurement results. In this work, a mobile application was developed to collate the PhotoPlethysmoGramm (PPG) waveform provided by a pulse oximeter and the electrocardiogram (ECG) for calculating the pulse transit time. This information is then indirectly related to the user's systolic blood pressure. The developed application successfully connects to the PPG and ECG monitoring devices using Bluetooth wireless connection and stores the data onto an online server. The pulse transit time is estimated in real time and the user's systolic blood pressure can be estimated after the system has been calibrated. The synchronization between the two devices was found to pose a challenge to this method of continuous blood pressure monitoring. However, the implemented continuous blood pressure monitoring system effectively serves as a proof of concept. This combined with the massive benefits that an accurate and robust continuous blood pressure monitoring system would provide indicates that it is certainly worthwhile to further develop this system.

  11. An Investigation of Pulse Transit Time as a Non-Invasive Blood Pressure Measurement Method

    International Nuclear Information System (INIS)

    McCarthy, B M; O'Flynn, B; Mathewson, A

    2011-01-01

    The objective of this paper is to examine the Pulse Transit Method (PTT) as a non-invasive means to track Blood Pressure over a short period of time. PTT was measured as the time it takes for an ECG R-wave to propagate to the finger, where it is detected by a photoplethysmograph sensor. The PTT method is ideal for continuous 24-hour Blood Pressure Measurement (BPM) since it is both cuff-less and non-invasive and therefore comfortable and unobtrusive for the patient. Other techniques, such as the oscillometric method, have shown to be accurate and reliable but require a cuff for operation, making them unsuitable for long term monitoring. Although a relatively new technique, the PTT method has shown to be able to accurately track blood pressure changes over short periods of time, after which re-calibration is necessary. The purpose of this study is to determine the accuracy of the method.

  12. Time-dependent local-to-normal mode transition in triatomic molecules

    Science.gov (United States)

    Cruz, Hans; Bermúdez-Montaña, Marisol; Lemus, Renato

    2018-01-01

    Time-evolution of the vibrational states of two interacting harmonic oscillators in the local mode scheme is presented. A local-to-normal mode transition (LNT) is identified and studied from temporal perspective through time-dependent frequencies of the oscillators. The LNT is established as a polyad-breaking phenomenon from the local standpoint for the stretching degrees of freedom in a triatomic molecule. This study is carried out in the algebraic representation of bosonic operators. The dynamics of the states are determined via the solutions of the corresponding nonlinear Ermakov equation and a local time-dependent polyad is obtained as a tool to identify the LNT. Applications of this formalism to H2O, CO2, O3 and NO2 molecules in the adiabatic, sudden and linear regime are considered.

  13. Direct simulation of groundwater transit-time distributions using the reservoir theory

    Science.gov (United States)

    Etcheverry, David; Perrochet, Pierre

    Groundwater transit times are of interest for the management of water resources, assessment of pollution from non-point sources, and quantitative dating of groundwaters by the use of environmental isotopes. The age of water is the time water has spent in an aquifer since it has entered the system, whereas the transit time is the age of water as it exits the system. Water at the outlet of an aquifer is a mixture of water elements with different transit times, as a consequence of the different flow-line lengths. In this paper, transit-time distributions are calculated by coupling two existing methods, the reservoir theory and a recent age-simulation method. Based on the derivation of the cumulative age distribution over the whole domain, the approach accounts for the whole hydrogeological framework. The method is tested using an analytical example and its applicability illustrated for a regional layered aquifer. Results show the asymmetry and multimodality of the transit-time distribution even in advection-only conditions, due to the aquifer geometry and to the velocity-field heterogeneity. Résumé Les temps de transit des eaux souterraines sont intéressants à connaître pour gérer l'évaluation des ressources en eau dans le cas de pollution à partir de sources non ponctuelles, et aussi pour dater quantitativement les eaux souterraines au moyen des isotopes du milieu. L'âge de l'eau est le temps qu'elle a passé dans un aquifère depuis qu'elle est entrée dans le système, alors que le temps de transit est l'âge de l'eau au moment où elle quitte le système. L'eau à la sortie d'un aquifère est un mélange d'eaux possédant différents temps de transit, du fait des longueurs différentes des lignes de courant suivies. Dans ce papier, les distributions des temps de transit sont calculées en couplant deux méthodes, la théorie du réservoir et une méthode récente de simulation des âges. Basée sur la dérivation de la distribution cumulées des âges sur

  14. Relationships between rumination time, metabolic conditions, and health status in dairy cows during the transition period.

    Science.gov (United States)

    Soriani, N; Trevisi, E; Calamari, L

    2012-12-01

    The main objective of this experiment was to monitor the rumination pattern during the transition period in primiparous (PR) and pluriparous (PL) dairy cows and to investigate its relationships with metabolic conditions, milk yield, and health status. The study was carried out in an experimental free-stall barn and involved 32 Italian Friesian cows (9 PR and 23 PL) during the transition phase. The rumination time (RT) was recorded with an automatic system (HR-Tag), and data were calculated and summarized in 2-h intervals. Blood samples were collected during the transition phase to assess biochemical variables related to energy, protein, and mineral metabolism, as well as markers of inflammatory conditions and some enzyme activity. Daily milk yield, BW, nutritional condition, and health status were also recorded. The average RT before calving (-20 to -6 d) was 463 min/d in PR (range 270 to 620) and 522 min/d in PL (range 411 to 640). In the early lactation [15 to 40 d in milk (DIM)], the average RT was 504 min/d in PR (range 400 to 585) and 562 min/d in PL (range 414 to 685) and was positively correlated with milk yield (r = 0.36; P Cows with reduced RT before calving maintained reduced RT after calving and suffered a greater frequency of disease than cows with greater RT in late pregnancy. Moreover, cows characterized by mild inflammatory conditions and without health disorders or only mild health disorders during the puerperium showed a greater average rumination time (over 520 min/d) during the first 10 d of lactation. Conversely, the decreased RT (450 min/d) during the first few days of lactation was observed in cows with subclinical diseases or health disorders. Cows affected by clinical mastitis during the trial showed a reduction of RT and a change in its variability already some days before the drug treatment. Our results suggest that the automatic measurement of RT is useful to predict calving time and to quickly obtain information on health status of the

  15. Impact of orocecal transit time on patient´s perception of lactose intolerance.

    Science.gov (United States)

    Casellas, Francesc; Aparici, Anna; Casaus, Maite; Rodríguez, Purificación; Malagelada, Juan R

    2013-01-01

    symptoms attributed to the lactose intolerance are an important public health issue because of their prevalence and social relevance. Also because they may cause undue rejection of dairy products consume with potential health consequences. Transit time is a putative factor implied in the severity of symptoms associated with lactose. to elucidate the relation between orocecal transit time (OCTT) and lactose intolerance symptoms. observational study in patients referred to a lactose hydrogen breath test who showed an increase in breath H2 excretion higher than 25 ppm. OCTT was measured with the breath test and symptoms of lactose tolerance with a validated scale. Symptoms were measured twice: before receiving the lactose, inquiring about self perceived symptoms when patients consumed dairy products at home ("home symptoms"), and again after completing the lactose breath test ("test symptoms"). 161 patients were included. There was no correlation between OCTT and home symptoms (r = -0.1). When OCTT was faster than 60 minutes, intensity of "test symptoms" was similar to "home symptoms". However, in patients with normal or slow OCTT, the "home symptoms" were more intense than the "test symptoms" (p lactose test load the symptoms were proportionately more intense with faster OCTT. in lactose maldigesters, selfreported symptoms of lactose intolerance are more pronounced at home than after a high lactose challenge. Intolerance symptoms that patients attributed to lactose consume at home are due to factors other than fast OCTT.

  16. Effect of closed loop cooling water transit time on containment cooling

    International Nuclear Information System (INIS)

    Smith, R.P.; Vossahlik, J.E.; Goodwin, E.F.

    1996-01-01

    Long term containment cooling analyses in nuclear plant systems are usually conducted assuming a quasi steady-state process, that is, a steady state evaluation of the cooling system is completed for each calculational step. In reality, fluid transport in the system, and heat addition to system components may affect the heat removal rate of the system. Transient effects occurring during system startup may affect the maximum temperatures experienced in the system. It is important to ensure that such transient effects do not affect operation of the system (e.g., cause a high temperature trip). To evaluate the effect of fluid transit delays, a closed loop cooling water system model has been developed that incorporates the fluid transport times when determining the closed loop cooling system performance. This paper describes the closed loop cooling system model as implemented in the CONTEMPT-LT/028 code. The evaluation of the transient temperature response of the closed loop cooling system using the model is described. The paper also describes the effect of fluid transit time on the overall containment cooling performance

  17. Phase transition of the susceptible-infected-susceptible dynamics on time-varying configuration model networks

    Science.gov (United States)

    St-Onge, Guillaume; Young, Jean-Gabriel; Laurence, Edward; Murphy, Charles; Dubé, Louis J.

    2018-02-01

    We present a degree-based theoretical framework to study the susceptible-infected-susceptible (SIS) dynamics on time-varying (rewired) configuration model networks. Using this framework on a given degree distribution, we provide a detailed analysis of the stationary state using the rewiring rate to explore the whole range of the time variation of the structure relative to that of the SIS process. This analysis is suitable for the characterization of the phase transition and leads to three main contributions: (1) We obtain a self-consistent expression for the absorbing-state threshold, able to capture both collective and hub activation. (2) We recover the predictions of a number of existing approaches as limiting cases of our analysis, providing thereby a unifying point of view for the SIS dynamics on random networks. (3) We obtain bounds for the critical exponents of a number of quantities in the stationary state. This allows us to reinterpret the concept of hub-dominated phase transition. Within our framework, it appears as a heterogeneous critical phenomenon: observables for different degree classes have a different scaling with the infection rate. This phenomenon is followed by the successive activation of the degree classes beyond the epidemic threshold.

  18. DA-9701 improves colonic transit time and symptoms in patients with functional constipation: A prospective study.

    Science.gov (United States)

    Kim, Su Young; Woo, Hyun Sun; Kim, Kyoung Oh; Choi, Sung Han; Kwon, Kwang An; Chung, Jun-Won; Kim, Yoon Jae; Kim, Jung Ho; Kim, Su Ji; Park, Dong Kyun

    2017-12-01

    DA-9701, a newly developed prokinetic agent formulated with Pharbitis Semen and Corydalis Tuber, has been shown to effectively treat functional dyspepsia. Recently, it has also been suspected to improve gastrointestinal motor function. The aims of this study were to assess the effect of DA-9701 on colonic transit time (CTT) and symptoms of functional constipation. Thirty-three patients with functional constipation based on the Rome III criteria were prospectively enrolled. The patients received 30-mg DA-9701 three times a day for 24 days. CTT was estimated initially and at the end of treatment. Symptoms such as spontaneous bowel movements, straining, stool form, feeling of incomplete emptying and anorectal blockage, abdominal discomfort and pain, overall defecation satisfaction, and incidence of adverse events were also analyzed. Twenty-seven patients completed the study. DA-9701 was associated with a significantly reduced CTT from 34.9 ± 17.6 to 23.7 ± 19.1 h (P = 0.001). Segmental CTT also significantly decreased after treatment (right CTT: from 16.8 [0.0-28.8] to 6.0 [0.0-25.2] hours, P DA-9701 accelerates colonic transit and safely improves symptoms in patients with functional constipation. Therefore, we suggest that this novel agent could help to treat patients with this condition. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  19. Suppression of the Transit -Time Instability in Large-Area Electron Beam Diodes

    Science.gov (United States)

    Myers, Matthew C.; Friedman, Moshe; Swanekamp, Stephen B.; Chan, Lop-Yung; Ludeking, Larry; Sethian, John D.

    2002-12-01

    Experiment, theory, and simulation have shown that large-area electron-beam diodes are susceptible to the transit-time instability. The instability modulates the electron beam spatially and temporally, producing a wide spread in electron energy and momentum distributions. The result is gross inefficiency in beam generation and propagation. Simulations indicate that a periodic, slotted cathode structure that is loaded with resistive elements may be used to eliminate the instability. Such a cathode has been fielded on one of the two opposing 60 cm × 200 cm diodes on the NIKE KrF laser at the Naval Research Laboratory. These diodes typically deliver 600 kV, 500 kA, 250 ns electron beams to the laser cell in an external magnetic field of 0.2 T. We conclude that the slotted cathode suppressed the transit-time instability such that the RF power was reduced by a factor of 9 and that electron transmission efficiency into the laser gas was improved by more than 50%.

  20. Suppression of the transit-time instability in large-area electron beam diodes

    International Nuclear Information System (INIS)

    Myers, Matthew C.; Friedman, Moshe; Sethian, John D.; Swanekamp, Stephen B.; Chan, L.-Y.; Ludeking, Larry

    2002-01-01

    Experiment, theory, and simulation have shown that large-area electron-beam diodes are susceptible to the transit-time instability. The instability modulates the electron beam spatially and temporally, producing a wide spread in electron energy and momentum distributions. The result is gross inefficiency in beam generation and propagation. Simulations indicate that a periodic, slotted cathode structure that is loaded with resistive elements may be used to eliminate the instability. Such a cathode has been fielded on one of the two opposing 60 cm x 200 cm diodes on the NIKE KrF laser at the Naval Research Laboratory. These diodes typically deliver 600 kV, 500 kA, 250 ns electron beams to the laser cell in an external magnetic field of 0.2 T. We conclude that the slotted cathode suppressed the transit-time instability such that the RF power was reduced by a factor of 9 and that electron transmission efficiency into the laser gas was improved by more than 50%

  1. Sport Transition of JPSS VIIRS Imagery for Night-time Applications

    Science.gov (United States)

    Fuell, Kevin; LeRoy, Anita; Smith, Matt; Miller, Steve; Kann, Diedre; Bernhardt, David; Reydell, Nezette; Cox, Robert

    2014-01-01

    The NASA/Short-term Prediction, Research, and Transition (SPoRT) Program and NOAA/Cooperative Institute for Research in the Atmosphere (CIRA) work within the NOAA/Joint Polar Satellite System (JPSS) Proving Ground to demonstrate the unique capabilities of the VIIRS instrument. Very similar to MODIS, the VIIRS instrument provides many high-resolution visible and infrared channels in a broad spectrum. In addition, VIIRS is equipped with a low-light sensor that is able to detect light emissions from the land and atmosphere as well as reflected sunlight by the lunar surface. This band is referred to as the Day-Night Band due to the sunlight being used at night to see cloud and topographic features just as one would typically see in day-time visible imagery. NWS forecast offices that collaborate with SPoRT and CIRA have utilized MODIS imagery in operations, but have longed for more frequent passes of polar-orbiting data. The VIIRS instrument enhances SPoRT collaborations with WFOs by providing another day and night-time pass, and at times two additional passes due to its large swath width. This means that multi-spectral, RGB imagery composites are more readily available to prepare users for their use in GOES-R era and high-resolution imagery for use in high-latitudes is more frequently able to supplement standard GOES imagery within the SPoRT Hybrid GEO-LEO product. The transition of VIIRS also introduces the new Day-Night Band capability to forecast operations. An Intensive Evaluation Period (IEP) was conducted in Summer 2013 with a group of "Front Range" NWS offices related to VIIRS night-time imagery. VIIRS single-channel imagery is able to better analyze the specific location of fire hotspots and other land features, as well as provide a more true measurement of various cloud and aerosol properties than geostationary measurements, especially at night. Viewed within the SPoRT Hybrid imagery, the VIIRS data allows forecasters to better interpret the more frequent, but

  2. Direct and real time probe of photoinduced structure transition in colossal magnetoresistive material

    Energy Technology Data Exchange (ETDEWEB)

    Li, Junjie [Physics Department, Florida State University, Tallahassee, Florida 32310 (United States); National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Wang, Xuan [Institute of physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190 (China); Zhou, Haidong [National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Zhou, Jun; Cao, Jianming, E-mail: jcao@magnet.fsu.edu [Physics Department, Florida State University, Tallahassee, Florida 32310 (United States); National High Magnetic Field Laboratory, Tallahassee, Florida 32310 (United States); Cheng, J. G. [Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712 (United States)

    2016-07-25

    We report a direct and real time measurement of photoinduced structure phase transition in single crystal La{sub 0.84}Sr{sub 0.16}MnO{sub 3} using femtosecond electron diffraction. The melting of orthorhombic lattice ordering under femtosecond optical excitation is found involving two distinct processes with different time scales, an initial fast melting of orthorhombic phase in about 4 ps and a subsequent slower transformation in 90 ps and longer timescales. The fast process is designated as the initial melting of orthorhombic phase induced by the Mn-O bond change that is most likely driven by the quenching of the dynamic Jahn-Teller distortion following the photo-excitation. The slow process is attributed to the growing of newly formed structure domain from the photo-excited sites to the neighboring non-excited orthorhombic sites.

  3. Two-Year Institution Part-Time Nurse Faculty Experiences During Role Transition and Identity Development: A Phenomenological Study.

    Science.gov (United States)

    Owens, Rhoda A

    This study explored two-year institution part-time nurse faculty's perceptions of their experiences during their role transitions from nurses in clinical practice to part-time clinical instructors. Part-time nurse faculty enter academia as expert clinicians, but most have little or no training in the pedagogy of effective student learning. A phenomenological study was used to explore the faculty role transition experiences. Findings support the proposition that six participants transitioned from their expert clinician to instructor identities; however, two continue in the process. Critical to this process are relationships with individuals in their environments, past and present experiences, the incentive to learn to be better instructors, and the importance of support and training. A model emerged, Process of Role Transition and Professional Identity Formation for Part-Time Clinical Instructors at Two-Year Institutions, that is potentially useful for administrators in developing individualized orientation and professional development programs.

  4. Short-Term Interferential Transabdominal Electrical Stimulation Did Not Change Oral-Rectal Transit Time in Piglets.

    Science.gov (United States)

    Tan, Andre Y F; Sourial, Magdy; Hutson, John M; Southwell, Bridget R

    2018-03-02

    Transcutaneous electrical stimulation (TES) using interferential current (IFC) is a new therapeutic treatment for constipation. Clinical studies show that TES-IFC for 3-6 months improves colonic transit, but it is not clear if short-term stimulation affects transit or the effect requires longer to develop. The aim of this study was to determine if TES-IFC for only four days affects oral-rectal transit time in healthy pigs. Twenty-two 4-5-week old large white female piglets had transit studies during week 4 and week 5 by placing a capsule containing 18 radiopaque plastic markers in the esophagus under anesthetic followed by x-rays at 6, 30, 54, and 78 hours. Animals were randomly assigned to active or control groups. The active group received TES for 30 min daily for four days. Interferential current was applied through four electrodes (4 × 4 cm), with two para-spinal just below the last rib and two on the belly at the same level. Stimulation was at 4000 Hz and 4080-4160 Hz with currents crossing through the abdominal cavity. Whole bowel transit times ranged from 7.7 to 72.2 hours, stomach transit from transit time from 5 to 53 hours. Transit times were the same for the control (median 28.4 hours) and TES-IFC (23.0 hours) groups in the prestimulation and stimulation weeks (control 23.0, TES-IFC 19.8 hours) with no change within or between groups. Four days of half-hour TES-IFC daily in healthy 5-week-old piglets did not change oral-rectal transit time. © 2018 International Neuromodulation Society.

  5. The scintigraphic determination of small intestinal transit time in patients with irritable bowel syndrome

    International Nuclear Information System (INIS)

    Marano, A.R.; Caride, V.J.; Shah, R.V.; Prokop, E.K.; Troncale, F.J.; McCallum, R.W.

    1984-01-01

    Diffuse disturbance in gastrointestinal motility may be present in patients with irritable bowel syndrome (IBS). To further investigate small intestinal motility in IBS patients small intestinal transit time (SITT) was determined and related to the symptom status. 11 female patients with IBS (mean age 29 years) were divided into those whose predominate symptom was diarrhea (N=6), and those with only constipation (N=5). All subjects ingested an isosmotic solution of lactulose (10 gm in 150cc of water) labeled with 99m-Tc-DTPA (Sn). The patient was studied supine under a 25 inch gamma camera with data collected at 1 frame per minute for 180 minutes or until activity appeared in the ascending colon. Regions of interest were selected over the cecum and ascending colon. The time of first appearance of radioactivity in the region of the cecum was taken as the small intestinal transit time. SITT in the 5 normal females was 98.7 +- 13 min (mean +- SEM). SITT in the IBS patients with diarrhea, 67.3 +- 7 min was significantly faster (p< 0.08). SITT in the constipated IBS patients, 126 +- 12 min, was slower than normals and significantly different from diarrhea patients (p< 0.001). These studies show that IBS patients with diarrhea have significantly faster SITT than normals while constipated IBS patients have significantly slower SITT than the diarrhea subgroup. Further, this study emphasizes the need to study the various symptomatic subgroups of IBs patients independently and indicates a possible role for abnormal SITT in the pathogenesis of IBS

  6. Canada's international response to HIV during times of global transition: a qualitative inquiry.

    Science.gov (United States)

    Nixon, Stephanie

    2011-04-01

    Canada's international response to HIV may be under threat given CIDA's new aid priorities that appear to exclude health. Drivers of this recent priority shift have been the influence of global aid trends among public sector donors and changes within the global HIV milieu itself. However, this is not the first time Canada has shifted in response to these two global trends. The era from 2000-2004 also witnessed dramatic changes in both the HIV field and in global thinking around international aid. As such, this article presents an evaluation of the Government of Canada's international response to HIV during the first era of transition (2000-2004) in order to derive lessons for decision-making around HIV in the current climate of change. In-depth, semi-structured interviews were conducted with 23 key informants with expertise regarding Canada's international response to HIV over time. Analysis involved multiple readings of transcripts to identify descriptive codes and establish intimacy with the data. Descriptive codes were then collapsed into thematic categories using a process of inductive reasoning. Canada's international response to HIV was perceived to be exemplary at times (e.g. seminal funding to WHO's "3-by-5" strategy), but also inconsistent (e.g., underutilized technical assistance capacity) and non-strategic (e.g., contradiction between investing in training health providers while poaching professionals to bolster Canada's workforce). Lessons from the 2000-2004 era of transition focus on strategic investments, the inextricable connection between HIV and development and strategy coherence. These results highlight that it is more constructive to ensure that Canadian development responses in all areas engage with both the upstream drivers of HIV as well as the impacts of the epidemic itself in order to achieve the greatest results from international investment and the most effective contributions to the lives of the people that these endeavours seek to

  7. The scintigraphic determination of small intestinal transit time in patients with irritable bowel syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Marano, A.R.; Caride, V.J.; Shah, R.V.; Prokop, E.K.; Troncale, F.J.; McCallum, R.W.

    1984-01-01

    Diffuse disturbance in gastrointestinal motility may be present in patients with irritable bowel syndrome (IBS). To further investigate small intestinal motility in IBS patients small intestinal transit time (SITT) was determined and related to the symptom status. 11 female patients with IBS (mean age 29 years) were divided into those whose predominate symptom was diarrhea (N=6), and those with only constipation (N=5). All subjects ingested an isosmotic solution of lactulose (10 gm in 150cc of water) labeled with 99m-Tc-DTPA (Sn). The patient was studied supine under a 25 inch gamma camera with data collected at 1 frame per minute for 180 minutes or until activity appeared in the ascending colon. Regions of interest were selected over the cecum and ascending colon. The time of first appearance of radioactivity in the region of the cecum was taken as the small intestinal transit time. SITT in the 5 normal females was 98.7 +- 13 min (mean +- SEM). SITT in the IBS patients with diarrhea, 67.3 +- 7 min was significantly faster (p< 0.08). SITT in the constipated IBS patients, 126 +- 12 min, was slower than normals and significantly different from diarrhea patients (p< 0.001). These studies show that IBS patients with diarrhea have significantly faster SITT than normals while constipated IBS patients have significantly slower SITT than the diarrhea subgroup. Further, this study emphasizes the need to study the various symptomatic subgroups of IBs patients independently and indicates a possible role for abnormal SITT in the pathogenesis of IBS.

  8. VIDEO CAPSULE ENDOSCOPY: A TOOL FOR THE ASSESSMENT OF SMALL BOWEL TRANSIT TIME

    Directory of Open Access Journals (Sweden)

    Reza A Hejazi

    2016-02-01

    Full Text Available Purpose: Video capsule endoscopy (VCE is a procedure that uses a wireless camera to take pictures of the gastrointestinal tract. A wireless motility capsule (WMC of a similar size has been developed, which measures pH, pressure, and temperature, and can be used to assess regional and total gastrointestinal transit times. VCE could also potentially be used as a tool for measuring small bowel transit time (SBTT.Methods: This study was designed to obtain SBTT from VCE and compare it with historical data generated by WMC. Gastric transit time (GTT was also measured. Patients were included if the indication for VCE was either iron deficiency anemia (IDA or overt obscure GI bleed (OOGIB and they did not have any known motility disorder. Results from VCE were also compared in diabetic versus non-diabetic patients. Results: There were a total of 147 VCE studies performed, including 42 for OOGIB and 105 for IDA. Median GTT and SBTT were 0.3 and 3.6 hours, respectively. The overall median GTT and SBTT were 0.3 and 3.6 hours, respectively, in the IDA group compared with 0.3 and 3.4 hours in the OOGIB group. When compared with WMC, the GTT and SBTT were significantly faster in both groups (GTT: 3.6 hours and SBTT: 4.6 hours. The median GTT and SBTT were not significantly different in diabetics versus non-diabetics: (GTT: 17.5 vs. 18.0 minutes (P=0.86 and SBTT: 3.9 hours (237 minutes vs. 3.8 hours (230 minutes, respectively (P=0.90.Conclusion: SBTT as measured using VCE is not significantly different in OOGIB compared with IDA. Both GTT and SBTT are significantly faster as assessed by VCE, which is initiated in the fasting state, compared with WMC measurement, which is initiated after a standard meal. In summary, VCE could potentially be used for measuring SBTT in the fasting state.

  9. Video Capsule Endoscopy: A Tool for the Assessment of Small Bowel Transit Time.

    Science.gov (United States)

    Hejazi, Reza A; Bashashati, Mohammad; Saadi, Mohammed; Mulla, Zuber D; Sarosiek, Irene; McCallum, Richard W; Zuckerman, Marc J

    2016-01-01

    Video capsule endoscopy (VCE) is a procedure that uses a wireless camera to take pictures of the gastrointestinal (GI) tract. A wireless motility capsule (WMC) of a similar size has been developed, which measures pH, pressure, and temperature and can be used to assess regional and total GI transit times. VCE could also potentially be used as a tool for measuring small bowel transit time (SBTT). This study was designed to obtain SBTT from VCE and compare it with historical data generated by WMC. Gastric transit time (GTT) was also measured. Patients were included if the indication for VCE was either iron deficiency anemia (IDA) or overt obscure GI bleed (OOGIB), and they did not have any known motility disorder. Results from VCE were also compared in diabetic vs. non-diabetic patients. There were a total of 147 VCE studies performed, including 42 for OOGIB and 105 for IDA. Median GTT and SBTT were 0.3 and 3.6 h, respectively. The overall median GTT and SBTT were 0.3 and 3.6 h, respectively, in the IDA group compared with 0.3 and 3.4 h in the OOGIB group. When compared with WMC, the GTT and SBTT were significantly faster in both groups (GTT: 3.6 h and SBTT: 4.6 h). The median GTT and SBTT were not significantly different in diabetics vs. non-diabetics [GTT: 17.5 vs. 18.0 min (P = 0.86) and SBTT: 3.9 h (237 min) vs. 3.8 h (230 min), respectively (P = 0.90)]. SBTT as measured using VCE is not significantly different in OOGIB compared with IDA. Both GTT and SBTT are significantly faster as assessed by VCE, which is initiated in the fasting state, compared with WMC measurement, which is initiated after a standard meal. In summary, VCE could potentially be used for measuring SBTT in the fasting state.

  10. Association of rumination time with subclinical ketosis in transition dairy cows.

    Science.gov (United States)

    Kaufman, E I; LeBlanc, S J; McBride, B W; Duffield, T F; DeVries, T J

    2016-07-01

    The objective of this study was to characterize the relationship between rumination and subclinical ketosis (SCK) in transition dairy cows. A study was conducted on 4 commercial dairy farms in eastern Ontario, Canada. A total of 339 Holstein dairy cows (107 primiparous and 232 multiparous) were monitored for rumination activity and SCK from 14 d before calving until 28 d after calving. Rumination was recorded daily using an automated monitoring system. A blood sample was taken from the coccygeal vein of each cow for measurement of β-hydroxybutyrate (BHB) once weekly throughout the 6-wk observation period. Cows with BHB ≥1.2mmol/L in any of the 4 postpartum samples were considered to have SCK. Cases of retained placenta, metritis, milk fever, or mastitis during the study period were also recorded. Cows were categorized into 1 of 4 groups: healthy cows (HLT) that had no SCK or any other recorded health problem (n=139); cows treated for at least one health issue other than SCK (HLT+; n=50); cows with SCK (hyperketonemia; HYK) with no other health problems during transition (n=97); or cows (HYK+) that had SCK and one or more other health problems (n=53). Daily rumination time was summarized by week and comparisons were made between HLT and HYK and HYK+. From 2 wk before calving (wk -2) to 4 wk after calving (wk +4), there was no difference in rumination time (409±9.8min/d) among HLT, HYK, and HYK+ cows in their first lactation. Multiparous cows in HLT spent an average of 459±11.3min/d ruminating from wk -2 to wk +4. Multiparous HYK cows ruminated 25±12.8min/d less than HLT cows, whereas HYK+ cows ruminated 44±15.6min/d less than HLT cows. The largest differences in rumination time between HLT and HYK+ cows were seen during wk -1, +1, and +2, when HYK+ cows ruminated 48±17.2, 73±16.0, and 65±19.4min/d less than HLT cows, respectively. In multiparous cows, increased odds of HYK were associated with greater milk yield in the previous lactation, greater loss of

  11. Noninvasive measurement of cerebrospinal fluid flow using an ultrasonic transit time flow sensor: a preliminary study.

    Science.gov (United States)

    Pennell, Thomas; Yi, Juneyoung L; Kaufman, Bruce A; Krishnamurthy, Satish

    2016-03-01

    OBJECT Mechanical failure-which is the primary cause of CSF shunt malfunction-is not readily diagnosed, and the specific reasons for mechanical failure are not easily discerned. Prior attempts to measure CSF flow noninvasively have lacked the ability to either quantitatively or qualitatively obtain data. To address these needs, this preliminary study evaluates an ultrasonic transit time flow sensor in pediatric and adult patients with external ventricular drains (EVDs). One goal was to confirm the stated accuracy of the sensor in a clinical setting. A second goal was to observe the sensor's capability to record real-time continuous CSF flow. The final goal was to observe recordings during instances of flow blockage or lack of flow in order to determine the sensor's ability to identify these changes. METHODS A total of 5 pediatric and 11 adult patients who had received EVDs for the treatment of hydrocephalus were studied in a hospital setting. The primary EVD was connected to a secondary study EVD that contained a fluid-filled pressure transducer and an in-line transit time flow sensor. Comparisons were made between the weight of the drainage bag and the flow measured via the sensor in order to confirm its accuracy. Data from the pressure transducer and the flow sensor were recorded continuously at 100 Hz for a period of 24 hours by a data acquisition system, while the hourly CSF flow into the drip chamber was recorded manually. Changes in the patient's neurological status and their time points were noted. RESULTS The flow sensor demonstrated a proven accuracy of ± 15% or ± 2 ml/hr. The flow sensor allowed real-time continuous flow waveform data recordings. Dynamic analysis of CSF flow waveforms allowed the calculation of the pressure-volume index. Lastly, the sensor was able to diagnose a blocked catheter and distinguish between the blockage and lack of flow. CONCLUSIONS The Transonic flow sensor accurately measures CSF output within ± 15% or ± 2 ml

  12. Reformulation of time-convolutionless mode-coupling theory near the glass transition

    Science.gov (United States)

    Tokuyama, Michio

    2017-10-01

    The time-convolutionless mode-coupling theory (TMCT) recently proposed is reformulated under the condition that one of two approximations, which have been used to formulate the original TMCT in addition to the MCT approximations done on a derivation of nonlinear memory function in terms of the intermediate-scattering function, is not employed because it causes unphysical results for intermediate times. The improved TMCT equation is then derived consistently under another approximation. It is first checked that the ergodic to non-ergodic transition obtained by a new equation is exactly the same as that obtained by an old one because the long-time dynamics of both equations coincides with each other. However, it is emphasized that a difference between them appears in the intermediate-time dynamics of physical quantities. Such a difference is explored numerically in the dynamics of a non-Gaussian parameter by employing the Percus-Yevick static structure factor to calculate the nonlinear memory function.

  13. Multiscaling for systems with a broad continuum of characteristic lengths and times: Structural transitions in nanocomposites.

    Science.gov (United States)

    Pankavich, S; Ortoleva, P

    2010-06-01

    The multiscale approach to N-body systems is generalized to address the broad continuum of long time and length scales associated with collective behaviors. A technique is developed based on the concept of an uncountable set of time variables and of order parameters (OPs) specifying major features of the system. We adopt this perspective as a natural extension of the commonly used discrete set of time scales and OPs which is practical when only a few, widely separated scales exist. The existence of a gap in the spectrum of time scales for such a system (under quasiequilibrium conditions) is used to introduce a continuous scaling and perform a multiscale analysis of the Liouville equation. A functional-differential Smoluchowski equation is derived for the stochastic dynamics of the continuum of Fourier component OPs. A continuum of spatially nonlocal Langevin equations for the OPs is also derived. The theory is demonstrated via the analysis of structural transitions in a composite material, as occurs for viral capsids and molecular circuits.

  14. Phase transitions between lower and higher level management learning in times of crisis: an experimental study based on synergetics.

    Science.gov (United States)

    Liening, Andreas; Strunk, Guido; Mittelstadt, Ewald

    2013-10-01

    Much has been written about the differences between single- and double-loop learning, or more general between lower level and higher level learning. Especially in times of a fundamental crisis, a transition between lower and higher level learning would be an appropriate reaction to a challenge coming entirely out of the dark. However, so far there is no quantitative method to monitor such a transition. Therefore we introduce theory and methods of synergetics and present results from an experimental study based on the simulation of a crisis within a business simulation game. Hypothesized critical fluctuations - as a marker for so-called phase transitions - have been assessed with permutation entropy. Results show evidence for a phase transition during the crisis, which can be interpreted as a transition between lower and higher level learning.

  15. Increasing patient safety with neonates via handoff communication during delivery: a call for interprofessional health care team training across GME and CME.

    Science.gov (United States)

    Vanderbilt, Allison A; Pappada, Scott M; Stein, Howard; Harper, David; Papadimos, Thomas J

    2017-01-01

    Hospitals have struggled for years regarding the handoff process of communicating patient information from one health care professional to another. Ineffective handoff communication is recognized as a serious patient safety risk within the health care community. It is essential to take communication into consideration when examining the safety of neonates who require immediate medical attention after birth; effective communication is vital for positive patient outcomes, especially with neonates in a delivery room setting. Teamwork and effective communication across the health care continuum are essential for providing efficient, quality care that leads to favorable patient outcomes. Interprofessional simulation and team training can benefit health care professionals by improving interprofessional competence, defined as one's knowledge of other professionals including an understanding of their training and skillsets, and role clarity. Interprofessional teams that include members with specialization in obstetrics, gynecology, and neonatology have the potential to considerably benefit from training effective handoff and communication practices that would ensure the safety of the neonate upon birth. We must strive to provide the most comprehensive systematic, standardized, interprofessional handoff communication training sessions for such teams, through Graduate Medical Education and Continuing Medical Education that will meet the needs across the educational continuum.

  16. Transition among synchronous schemes in coupled nonidentical multiple time delay systems

    International Nuclear Information System (INIS)

    Thang Manh Hoang

    2009-01-01

    We present the transition among possible synchronous schemes in coupled nonidentical multiple time delay systems, i.e., lag, projective-lag, complete, anticipating and projective-anticipating synchronization. The number of nonlinear transforms in the master's equation can be different from that in slave's, and nonlinear transforms can be in various forms. The driving signal is the sum of nonlinearly transformed components of delayed state variable. Moreover, the equation representing for driving signal is constructed exactly so that the difference between the master's and slave's structures is complemented. The sufficient condition for synchronization is considered by the Krasovskii-Lyapunov theory. The specific examples will demonstrate and verify the effectiveness of the proposed models.

  17. Continuous-time quantum walk on an extended star graph: Trapping and superradiance transition

    Science.gov (United States)

    Yalouz, Saad; Pouthier, Vincent

    2018-02-01

    A tight-binding model is introduced for describing the dynamics of an exciton on an extended star graph whose central node is occupied by a trap. On this graph, the exciton dynamics is governed by two kinds of eigenstates: many eigenstates are associated with degenerate real eigenvalues insensitive to the trap, whereas three decaying eigenstates characterized by complex energies contribute to the trapping process. It is shown that the excitonic population absorbed by the trap depends on the size of the graph, only. By contrast, both the size parameters and the absorption rate control the dynamics of the trapping. When these parameters are judiciously chosen, the efficiency of the transfer is optimized resulting in the minimization of the absorption time. Analysis of the eigenstates reveals that such a feature arises around the superradiance transition. Moreover, depending on the size of the network, two situations are highlighted where the transport efficiency is either superoptimized or suboptimized.

  18. Further time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. [Argonne National Lab., IL (United States). Advanced Photon Source Accelerator Systems Div.; Wilke, M.D. [Los Alamos National Lab., NM (United States)

    1992-12-31

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 {mu}s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatialposition and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kick effects are reported as a function of charge.

  19. Further time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. (Argonne National Lab., IL (United States). Advanced Photon Source Accelerator Systems Div.); Wilke, M.D. (Los Alamos National Lab., NM (United States))

    1992-01-01

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 [mu]s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatialposition and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kick effects are reported as a function of charge.

  20. Time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. (Argonne National Lab., IL (United States)); Wilke, M.D. (Los Alamos National Lab., NM (United States))

    1992-01-01

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 {mu}s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatial position and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kicks are reported as a function of charge.

  1. Time-resolved electron-beam characterizations with optical transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H. [Argonne National Lab., IL (United States); Wilke, M.D. [Los Alamos National Lab., NM (United States)

    1992-09-01

    Time-resolved characterizations of electron beams using optical transition radiation (OTR) as a prompt conversion mechanism have recently been extended on the Los Alamos Free-electron Laser (FEL) facility 40-MeV linac. Two key timescales for rf-linac driven FELs are the micropulse (10 ps) and the macropulse (5 {mu}s to 1 ms). In the past we have used gated, intensified cameras to select a single or few micropulses (25 to 400 ns gate width) out of the pulse train to evaluate submacropulse effects. Recently, we have obtained some of the first measurements of micropulse bunch length (7 to 10 ps) and submacropulse spatial position and profile using OTR and a Hamamatsu streak camera. Additionally, micropulse elongation effects and head-to-tail transverse kicks are reported as a function of charge.

  2. Time-Resolved Emittance Characterization of an Induction Linac Beam using Optical Transition Radiation

    International Nuclear Information System (INIS)

    Le Sage, G P

    2002-01-01

    An induction linac is used by Lawrence Livermore National Laboratory to perform radiographic testing at the Flash X-ray Radiography facility. Emittance characterization is important since x-ray spot size impacts the resolution of shadow-graphs. Due to the long pulse length, high current, and beam energy, emittance measurement using Optical Transition Radiation is an attractive alternative for reasons that will be described in the text. The utility of OTR-based emittance measurement has been well demonstrated for both RF and induction linacs. We describe the time-resolved emittance characterization of an induction linac electron beam. We have refined the optical collection system for the induction linac application, and have demonstrated a new technique for probing the divergence of a subset of the beam profile. The experimental apparatus, data reduction, and conclusions will be presented. Additionally, a new scheme for characterizing the correlation between beam divergence and spatial coordinates within the beam profile will be described

  3. Time-Resolved Emittance Characterization of an Induction Linac Beam using Optical Transition Radiation

    CERN Document Server

    Le Sage, G P

    2002-01-01

    An induction linac is used by Lawrence Livermore National Laboratory to perform radiographic testing at the Flash X-ray Radiography facility. Emittance characterization is important since x-ray spot size impacts the resolution of shadow-graphs. Due to the long pulse length, high current, and beam energy, emittance measurement using Optical Transition Radiation is an attractive alternative for reasons that will be described in the text. The utility of OTR-based emittance measurement has been well demonstrated for both RF and induction linacs. We describe the time-resolved emittance characterization of an induction linac electron beam. We have refined the optical collection system for the induction linac application, and have demonstrated a new technique for probing the divergence of a subset of the beam profile. The experimental apparatus, data reduction, and conclusions will be presented. Additionally, a new scheme for characterizing the correlation between beam divergence and spatial coordinates within the b...

  4. Xylanase, protease and superdosing phytase interactions in broiler performance, carcass yield and digesta transit time

    Directory of Open Access Journals (Sweden)

    Tiago T. dos Santos

    2017-06-01

    Full Text Available The interaction of xylanase, protease and superdosing (1,500 FTU/kg phytase in a 2 × 2 × 2 factorial arrangement was studied in broilers fed sorghum-based diets. A total of 2,800 one-day-old unsexed Ross 308 chicks were housed in 56 pens with 50 birds per pen, with or without inclusion of xylanase, protease and phytase, totaling 8 treatments and 7 replicates per treatment. Body weight (BW and feed intake (FI were measured at 21 and 42 days of age, and mortality corrected feed conversion ratio (FCR was calculated for each period and cumulatively. Tibia ash and carcass yield were determined in 2 birds per replicate at 21 and 42 days of age, respectively. Digesta transit time was determined at 21, 28, 35 and 42 days of age using 5 birds per replicate. Results showed that superdosing phytase increased BW and FI at 42 days of age (P < 0.05 and xylanase improved FCR (P < 0.05. Xylanase and phytase also positively influenced carcass yield and breast weight, respectively. Overall, inclusion of superdosing phytase increased transit time when included in a diet containing xylanase, and no change with protease inclusion. In conclusion, the beneficial effects of xylanase, protease and superdosing phytase in broiler performance were not additive. This limitation is likely not related to the lack of efficacy of any one of the individual enzymes but to a limitation of the bird to respond additively to successive additions of enzymes.

  5. Relationships between transit time in man and in vitro fermentation of dietary fiber by fecal bacteria.

    Science.gov (United States)

    Oufir, L E; Barry, J L; Flourié, B; Cherbut, C; Cloarec, D; Bornet, F; Galmiche, J P

    2000-08-01

    To assess the effects of drug-induced changes in mean transit time (MTT) on the activity of human fecal flora in vitro. The activity of fecal flora was estimated by the ability of a fecal inoculum to ferment a substrate (beet fiber) in vitro in a batch system for 24 h. The inoculum was collected from 8 healthy volunteers studied during three 3-week randomized periods, who received a controlled diet alone (control period) or the same diet with either cisapride or loperamide. Cisapride and loperamide were adjusted in order to halve and double MTT measured during the control period. At the end of each period, the percentage disappearance of the initial added substrate and the concentration and the profile of short-chain fatty acids (SCFAs), were determined. In the control period, the pH of the inoculum and SCFA concentration were inversely related to MTT (P=0.0001). Individual SCFA production was also significantly related to MTT (P<0.01). Cisapride-reduced transit time was associated with a significant rise in the concentrations of total SCFAs (P<0.05), propionic and butyric acids (P<0.05) and the percentage substrate disappearance (P<0.05). Inverse relations were observed during the loperamide period. Moreover, MTT was inversely related to the percentage substrate disappearance (P<0.001), SCFA production (P<0.001) and butyrate production (P<0.0005). Changes in MTT alter bacterial activity and modify the bacterial pathways affecting the proportion of individual SCFAs. European Journal of Clinical Nutrition (2000) 54, 603-609

  6. Kinetics of the stress induced phase transition in quartz by real-time neutron scattering

    International Nuclear Information System (INIS)

    Gibhardt, H.; Eckold, G.; Guethoff, F.

    1999-01-01

    Complete text of publication follows. The stability regime of the incommensurate phase of quartz is influenced by uniaxial stress. Hence, the phase transition can be induced under isothermal conditions by the application of external mechanical forces. Using real-time neutron scattering the time evolution of structural changes is investigated id detail during stress variations. The time dependent behaviour of the satellite reflection is compared with that one of the fundamental Bragg reflection which - via primary extinction - gives information about the perfection of the crystal. On increasing stress the perfection of the lattice is destroyed immediately while the modulated structure is built up with a delay of about 1 s. Decreasing the stress leads to a reverse behaviour. Moreover, there is evidence that under periodical load residual non-relaxed strain fields survive leading to a different temperature dependence as compared to static conditions. This finding is compatible with pronounced hysteresis effects observed under cycling stress. It is argued that these residual strains are associated with non-relaxed topological 4-line defects, that drive the structural changes in quartz (1). (author)

  7. Noncontact sphygmomanometer based on pulse-wave transit time between the face and hand

    Science.gov (United States)

    Nakano, Kazuya; Ohnishi, Takashi; Nishidate, Izumi; Haneishi, Hideaki

    2018-02-01

    Systolic blood pressure (SBP) is highly sensitive to various factors such as psychological stress, and hence its continuous monitoring is essential to evaluate different health conditions. However, conventional sphygmomanometers cannot continuously measure SBP given the time-consuming setup based on a pressure cuff. Moreover, continuous biological signal monitoring is more comfortable when no sensors are attached. A solution for continuous SBP estimation is based on pulse transit time (PTT), which determines the time difference between two pulse waves at different body parts. In previous studies, we successfully measured the PTT using a contactless setup composed by two digital color cameras recording the face and hand of subjects. Then, the acquired images were transformed into blood volume by combining multiple regression analysis and a Monte Carlo method. As a result, the delay among images allowed to determine the PPT from pulse waves. In this study, we simultaneously measured SBP and PTT by using a sphygmomanometer and the two cameras, respectively. We evaluated SBP increases (i.e., stressful situations) and the corresponding PPT by asking participants to either grasp a handgrip or momentarily interrupting breath. We also determined the SBP and PTT without asking for such exercises. Comparison results show that the mean PTT under stress was significantly lower than that without stress, which is consistent with an increased SBP. Finally, we related the SBP and PTT by a nonlinear formula with a coefficient of determination of 0.59, thus confirming the effectiveness of the proposed system.

  8. Anthropogenic CO2 in the oceans estimated using transit time distributions

    International Nuclear Information System (INIS)

    Waugh, D.W.; McNeil, B.I.

    2006-01-01

    The distribution of anthropogenic carbon (Cant) in the oceans is estimated using the transit time distribution (TTD) method applied to global measurements of chlorofluorocarbon-12 (CFC12). Unlike most other inference methods, the TTD method does not assume a single ventilation time and avoids the large uncertainty incurred by attempts to correct for the large natural carbon background in dissolved inorganic carbon measurements. The highest concentrations and deepest penetration of anthropogenic carbon are found in the North Atlantic and Southern Oceans. The estimated total inventory in 1994 is 134 Pg-C. To evaluate uncertainties the TTD method is applied to output from an ocean general circulation model (OGCM) and compared the results to the directly simulated Cant. Outside of the Southern Ocean the predicted Cant closely matches the directly simulated distribution, but in the Southern Ocean the TTD concentrations are biased high due to the assumption of 'constant disequilibrium'. The net result is a TTD overestimate of the global inventory by about 20%. Accounting for this bias and other centred uncertainties, an inventory range of 94-121 Pg-C is obtained. This agrees with the inventory of Sabine et al., who applied the DeltaC* method to the same data. There are, however, significant differences in the spatial distributions: The TTD estimates are smaller than DeltaC* in the upper ocean and larger at depth, consistent with biases expected in DeltaC* given its assumption of a single parcel ventilation time

  9. Enhancing pairwise state-transition weights: A new weighting scheme in simulated tempering that can minimize transition time between a pair of conformational states

    Science.gov (United States)

    Qiao, Qin; Zhang, Hou-Dao; Huang, Xuhui

    2016-04-01

    Simulated tempering (ST) is a widely used enhancing sampling method for Molecular Dynamics simulations. As one expanded ensemble method, ST is a combination of canonical ensembles at different temperatures and the acceptance probability of cross-temperature transitions is determined by both the temperature difference and the weights of each temperature. One popular way to obtain the weights is to adopt the free energy of each canonical ensemble, which achieves uniform sampling among temperature space. However, this uniform distribution in temperature space may not be optimal since high temperatures do not always speed up the conformational transitions of interest, as anti-Arrhenius kinetics are prevalent in protein and RNA folding. Here, we propose a new method: Enhancing Pairwise State-transition Weights (EPSW), to obtain the optimal weights by minimizing the round-trip time for transitions among different metastable states at the temperature of interest in ST. The novelty of the EPSW algorithm lies in explicitly considering the kinetics of conformation transitions when optimizing the weights of different temperatures. We further demonstrate the power of EPSW in three different systems: a simple two-temperature model, a two-dimensional model for protein folding with anti-Arrhenius kinetics, and the alanine dipeptide. The results from these three systems showed that the new algorithm can substantially accelerate the transitions between conformational states of interest in the ST expanded ensemble and further facilitate the convergence of thermodynamics compared to the widely used free energy weights. We anticipate that this algorithm is particularly useful for studying functional conformational changes of biological systems where the initial and final states are often known from structural biology experiments.

  10. Enhancing pairwise state-transition weights: A new weighting scheme in simulated tempering that can minimize transition time between a pair of conformational states

    International Nuclear Information System (INIS)

    Qiao, Qin; Zhang, Hou-Dao; Huang, Xuhui

    2016-01-01

    Simulated tempering (ST) is a widely used enhancing sampling method for Molecular Dynamics simulations. As one expanded ensemble method, ST is a combination of canonical ensembles at different temperatures and the acceptance probability of cross-temperature transitions is determined by both the temperature difference and the weights of each temperature. One popular way to obtain the weights is to adopt the free energy of each canonical ensemble, which achieves uniform sampling among temperature space. However, this uniform distribution in temperature space may not be optimal since high temperatures do not always speed up the conformational transitions of interest, as anti-Arrhenius kinetics are prevalent in protein and RNA folding. Here, we propose a new method: Enhancing Pairwise State-transition Weights (EPSW), to obtain the optimal weights by minimizing the round-trip time for transitions among different metastable states at the temperature of interest in ST. The novelty of the EPSW algorithm lies in explicitly considering the kinetics of conformation transitions when optimizing the weights of different temperatures. We further demonstrate the power of EPSW in three different systems: a simple two-temperature model, a two-dimensional model for protein folding with anti-Arrhenius kinetics, and the alanine dipeptide. The results from these three systems showed that the new algorithm can substantially accelerate the transitions between conformational states of interest in the ST expanded ensemble and further facilitate the convergence of thermodynamics compared to the widely used free energy weights. We anticipate that this algorithm is particularly useful for studying functional conformational changes of biological systems where the initial and final states are often known from structural biology experiments.

  11. Enhancing pairwise state-transition weights: A new weighting scheme in simulated tempering that can minimize transition time between a pair of conformational states

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, Qin, E-mail: qqiao@ust.hk; Zhang, Hou-Dao [Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); Huang, Xuhui, E-mail: xuhuihuang@ust.hk [Department of Chemistry, Division of Biomedical Engineering, Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); The HKUST Shenzhen Research Institute, Shenzhen (China)

    2016-04-21

    Simulated tempering (ST) is a widely used enhancing sampling method for Molecular Dynamics simulations. As one expanded ensemble method, ST is a combination of canonical ensembles at different temperatures and the acceptance probability of cross-temperature transitions is determined by both the temperature difference and the weights of each temperature. One popular way to obtain the weights is to adopt the free energy of each canonical ensemble, which achieves uniform sampling among temperature space. However, this uniform distribution in temperature space may not be optimal since high temperatures do not always speed up the conformational transitions of interest, as anti-Arrhenius kinetics are prevalent in protein and RNA folding. Here, we propose a new method: Enhancing Pairwise State-transition Weights (EPSW), to obtain the optimal weights by minimizing the round-trip time for transitions among different metastable states at the temperature of interest in ST. The novelty of the EPSW algorithm lies in explicitly considering the kinetics of conformation transitions when optimizing the weights of different temperatures. We further demonstrate the power of EPSW in three different systems: a simple two-temperature model, a two-dimensional model for protein folding with anti-Arrhenius kinetics, and the alanine dipeptide. The results from these three systems showed that the new algorithm can substantially accelerate the transitions between conformational states of interest in the ST expanded ensemble and further facilitate the convergence of thermodynamics compared to the widely used free energy weights. We anticipate that this algorithm is particularly useful for studying functional conformational changes of biological systems where the initial and final states are often known from structural biology experiments.

  12. Characterization of type, position and dimension of flaws by transit time locus curves of ultrasonic inspections - ALOK. Pt. 2

    International Nuclear Information System (INIS)

    Grohs, B.; Barbian, O.A.; Kappes, W.; Paul, H.

    1981-01-01

    With automatic ultrasonic testing, flaws can be detected and described and thus characterized according to their type, position and dimensions. During scanning of a test object, the flaws are registered by many different pathways and many different acoustic irradiation directions. The transit time locus curve represents the distance between the relfecting points of a flaw and the source in dependence of the probe position; hence, information on flaw position and dimensions can be derived from this curve. If the sound velocity is known, the transit path can then be calculated from the transit time. This requires, above all, a constant sound velocity along the whole transit path. Various methods are presented for reconstructing the flaw border in the plane of incidence. (orig./RW) [de

  13. Increasing patient safety with neonates via handoff communication during delivery: a call for interprofessional health care team training across GME and CME

    Directory of Open Access Journals (Sweden)

    Vanderbilt AA

    2017-06-01

    Full Text Available Allison A Vanderbilt,1 Scott M Pappada,2 Howard Stein,3 David Harper,4 Thomas J Papadimos5 1Department of Family Medicine, 2Department of Anesthesiology, College of Medicine and Life Sciences, University of Toledo, 3Department of Pediatrics, ProMedica Toledo Children’s Hospital, 4Department of Obstetrics and Gynecology, ProMedica Toledo Hospital, 5Department of Anesthesiology, College of Medicine and the Life Sciences, University of Toledo, Toledo, OH, USA Abstract: Hospitals have struggled for years regarding the handoff process of communicating patient information from one health care professional to another. Ineffective handoff communication is recognized as a serious patient safety risk within the health care community. It is essential to take communication into consideration when examining the safety of neonates who require immediate medical attention after birth; effective communication is vital for positive patient outcomes, especially with neonates in a delivery room setting. Teamwork and effective communication across the health care continuum are essential for providing efficient, quality care that leads to favorable patient outcomes. Interprofessional simulation and team training can benefit health care professionals by improving interprofessional competence, defined as one’s knowledge of other professionals including an understanding of their training and skillsets, and role clarity. Interprofessional teams that include members with specialization in obstetrics, gynecology, and neonatology have the potential to considerably benefit from training effective handoff and communication practices that would ensure the safety of the neonate upon birth. We must strive to provide the most comprehensive systematic, standardized, interprofessional handoff communication training sessions for such teams, through Graduate Medical Education and Continuing Medical Education that will meet the needs across the educational continuum. Keywords

  14. Estimation of Catchment Transit Time in Fuji River Basin by using an improved Tank model

    Science.gov (United States)

    Wenchao, M.; Yamanaka, T.; Wakiyama, Y.; Wang, P.

    2013-12-01

    As an important parameter that reflects the characteristics of catchments, the catchment transit time (CTT) has been given much more widely attentions especially in recent years. The CTT is defined as the time water spends travelling through a catchment to the stream network [1], and it describes how catchments retain and release water and solutes and thus control geochemical and biogeochemical cycling and contamination persistence [2]. The objectives of the present study are to develop a new approach for estimating CTT without prior information on such TTD functions and to apply it to the Fuji River basin in the Central Japan Alps Region. In this study, an improved Tank model was used to compute mean CTT and TTD functions simultaneously. It involved water fluxes and isotope mass balance. Water storage capacity in the catchment, which strongly affects CTT, is reflected in isotope mass balance more sensitively than in water fluxes. A model calibrated with observed discharge and isotope data is used for virtual age tracer computation to estimate CTT. This model does not only consider the hydrological data and physical process of the research area but also reflects the actual TTD with considering the geological condition, land use and the other catchment-hydrological conditions. For the calibration of the model, we used river discharge record obtained by the Ministry of Land, Infrastructure and Transportation, and are collecting isotope data of precipitation and river waters monthly or semi-weekly. Three sub-catchments (SC1~SC3) in the Fuji River basin was selected to test the model with five layers: the surface layer, upper-soil layer, lower-soil layer, groundwater aquifer layer and bedrock layer (Layer 1- Layer 5). The evaluation of the model output was assessed using Nash-Sutcliffe efficiency (NSE), root mean square error-observations standard deviation ratio (RSR), and percent bias (PBIAS). Using long time-series of discharge records for calibration, the simulated

  15. Intracranial contrast transit times on digital subtraction angiography decrease more in patients with delayed intraparenchymal hemorrhage after Pipeline.

    Science.gov (United States)

    Brunozzi, Denise; Shakur, Sophia F; Charbel, Fady T; Alaraj, Ali

    2018-04-01

    Background Pipeline embolization devices (PEDs) are used for endovascular treatment of cerebral aneurysms but can be associated with delayed ipsilateral intraparenchymal hemorrhage (DIPH). Changes in intracranial hemodynamics after PED are poorly understood. Objective Here, we assess hemodynamic changes after PED in patients and compare these changes in patients with and without DIPH (DIPH+ and DIPH-). Methods Records of patients with distal internal carotid artery (ICA) aneurysms treated with PED at our institution between 2012 and 2017 were retrospectively reviewed. Regions of interest were selected proximally to PED over the cavernous ICA and distally over the middle cerebral artery (MCA), and then transit times were determined using syngo iFlow software (Siemens). Ratio of MCA to ICA transit time was compared before, after treatment, and at follow-up. Ratios were also compared between DIPH+ and DIPH- subgroups. Correlations between aneurysm size, age, and ratios were investigated. Results Fifty-three patients were included. The ratio of MCA to ICA transit time decreased significantly after PED deployment (1.13 vs. 1.22, p transit time decreases following PED treatment and decreases more in patients with DIPH. These contrast transit time changes can be detected in real time immediately after PED deployment.

  16. Comparison of active-set method deconvolution and matched-filtering for derivation of an ultrasound transit time spectrum

    International Nuclear Information System (INIS)

    Wille, M-L; Langton, C M; Zapf, M; Ruiter, N V; Gemmeke, H

    2015-01-01

    The quality of ultrasound computed tomography imaging is primarily determined by the accuracy of ultrasound transit time measurement. A major problem in analysis is the overlap of signals making it difficult to detect the correct transit time. The current standard is to apply a matched-filtering approach to the input and output signals. This study compares the matched-filtering technique with active set deconvolution to derive a transit time spectrum from a coded excitation chirp signal and the measured output signal. The ultrasound wave travels in a direct and a reflected path to the receiver, resulting in an overlap in the recorded output signal. The matched-filtering and deconvolution techniques were applied to determine the transit times associated with the two signal paths. Both techniques were able to detect the two different transit times; while matched-filtering has a better accuracy (0.13 μs versus 0.18 μs standard deviations), deconvolution has a 3.5 times improved side-lobe to main-lobe ratio. A higher side-lobe suppression is important to further improve image fidelity. These results suggest that a future combination of both techniques would provide improved signal detection and hence improved image fidelity. (note)

  17. Effects of Cereal, Fruit and Vegetable Fibers on Human Fecal Weight and Transit Time: A Comprehensive Review of Intervention Trials

    Directory of Open Access Journals (Sweden)

    Jan de Vries

    2016-03-01

    Full Text Available Cereal fibers are known to increase fecal weight and speed transit time, but far less data are available on the effects of fruits and vegetable fibers on regularity. This study provides a comprehensive review of the impact of these three fiber sources on regularity in healthy humans. We identified English-language intervention studies on dietary fibers and regularity and performed weighted linear regression analyses for fecal weight and transit time. Cereal and vegetable fiber groups had comparable effects on fecal weight; both contributed to it more than fruit fibers. Less fermentable fibers increased fecal weight to a greater degree than more fermentable fibers. Dietary fiber did not change transit time in those with an initial time of <48 h. In those with an initial transit time ≥48 h, transit time was reduced by approximately 30 min per gram of cereal, fruit or vegetable fibers, regardless of fermentability. Cereal fibers have been studied more than any other kind in relation to regularity. This is the first comprehensive review comparing the effects of the three major food sources of fiber on bowel function and regularity since 1993.

  18. Effects of Cereal, Fruit and Vegetable Fibers on Human Fecal Weight and Transit Time: A Comprehensive Review of Intervention Trials.

    Science.gov (United States)

    de Vries, Jan; Birkett, Anne; Hulshof, Toine; Verbeke, Kristin; Gibes, Kernon

    2016-03-02

    Cereal fibers are known to increase fecal weight and speed transit time, but far less data are available on the effects of fruits and vegetable fibers on regularity. This study provides a comprehensive review of the impact of these three fiber sources on regularity in healthy humans. We identified English-language intervention studies on dietary fibers and regularity and performed weighted linear regression analyses for fecal weight and transit time. Cereal and vegetable fiber groups had comparable effects on fecal weight; both contributed to it more than fruit fibers. Less fermentable fibers increased fecal weight to a greater degree than more fermentable fibers. Dietary fiber did not change transit time in those with an initial time of <48 h. In those with an initial transit time ≥48 h, transit time was reduced by approximately 30 min per gram of cereal, fruit or vegetable fibers, regardless of fermentability. Cereal fibers have been studied more than any other kind in relation to regularity. This is the first comprehensive review comparing the effects of the three major food sources of fiber on bowel function and regularity since 1993.

  19. Starting Out: A time-lagged study of new graduate nurses' transition to practice.

    Science.gov (United States)

    Laschinger, Heather K Spence; Cummings, Greta; Leiter, Michael; Wong, Carol; MacPhee, Maura; Ritchie, Judith; Wolff, Angela; Regan, Sandra; Rhéaume-Brüning, Ann; Jeffs, Lianne; Young-Ritchie, Carol; Grinspun, Doris; Gurnham, Mary Ellen; Foster, Barbara; Huckstep, Sherri; Ruffolo, Maurio; Shamian, Judith; Burkoski, Vanessa; Wood, Kevin; Read, Emily

    2016-05-01

    As the nursing profession ages, new graduate nurses are an invaluable health human resource. The purpose of this study was to investigate factors influencing new graduate nurses' successful transition to their full professional role in Canadian hospital settings and to determine predictors of job and career satisfaction and turnover intentions over a one-year time period in their early employment. A national two-wave survey of new graduate nurses across Canada. A random sample of 3906 Registered Nurses with less than 3 years of experience currently working in direct patient care was obtained from the provincial registry databases across Canada. At Time 1, 1020 of 3743 eligible nurses returned completed questionnaires (usable response rate=27.3%). One year later, Time 1 respondents were mailed a follow-up survey; 406 returned a completed questionnaire (response rate=39.8%). Surveys containing standardized questionnaires were mailed to participants' home address. Descriptive statistics, correlations, and hierarchical linear regression analyses were conducted using SPSS software. Overall, new graduate nurses were positive about their experiences and committed to nursing. However, over half of new nurses in the first year of practice reported high levels of emotional exhaustion and many witnessed or experienced incivility (24-42%) at work. Findings from hierarchical linear regression analyses revealed that situational and personal factors explained significant amounts of variance in new graduate nurses' job and career satisfaction and turnover intentions. Cynicism was a significant predictor of all four outcomes one year later, while Psycap predicted job and career satisfaction and career turnover intentions. Results provide a look into the worklife experiences of Canadian new graduate nurses over a one-year time period and identify factors that influence their job-related outcomes. These findings show that working conditions for new graduate nurses are generally

  20. Interacting opinion and disease dynamics in multiplex networks: Discontinuous phase transition and nonmonotonic consensus times

    Science.gov (United States)

    Velásquez-Rojas, Fátima; Vazquez, Federico

    2017-05-01

    Opinion formation and disease spreading are among the most studied dynamical processes on complex networks. In real societies, it is expected that these two processes depend on and affect each other. However, little is known about the effects of opinion dynamics over disease dynamics and vice versa, since most studies treat them separately. In this work we study the dynamics of the voter model for opinion formation intertwined with that of the contact process for disease spreading, in a population of agents that interact via two types of connections, social and contact. These two interacting dynamics take place on two layers of networks, coupled through a fraction q of links present in both networks. The probability that an agent updates its state depends on both the opinion and disease states of the interacting partner. We find that the opinion dynamics has striking consequences on the statistical properties of disease spreading. The most important is that the smooth (continuous) transition from a healthy to an endemic phase observed in the contact process, as the infection probability increases beyond a threshold, becomes abrupt (discontinuous) in the two-layer system. Therefore, disregarding the effects of social dynamics on epidemics propagation may lead to a misestimation of the real magnitude of the spreading. Also, an endemic-healthy discontinuous transition is found when the coupling q overcomes a threshold value. Furthermore, we show that the disease dynamics delays the opinion consensus, leading to a consensus time that varies nonmonotonically with q in a large range of the model's parameters. A mean-field approach reveals that the coupled dynamics of opinions and disease can be approximately described by the dynamics of the voter model decoupled from that of the contact process, with effective probabilities of opinion and disease transmission.

  1. Transit Timing Observations from Kepler: II. Confirmation of Two Multiplanet Systems via a Non-parametric Correlation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Eric B.; /Florida U.; Fabrycky, Daniel C.; /Lick Observ.; Steffen, Jason H.; /Fermilab; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Fressin, Francois; /Harvard-Smithsonian Ctr. Astrophys.; Holman, Matthew J.; /Harvard-Smithsonian Ctr. Astrophys.; Lissauer, Jack J.; /NASA, Ames; Moorhead, Althea V.; /Florida U.; Morehead, Robert C.; /Florida U.; Ragozzine, Darin; /Harvard-Smithsonian Ctr. Astrophys.; Rowe, Jason F.; /NASA, Ames /SETI Inst., Mtn. View /San Diego State U., Astron. Dept.

    2012-01-01

    We present a new method for confirming transiting planets based on the combination of transit timing variations (TTVs) and dynamical stability. Correlated TTVs provide evidence that the pair of bodies are in the same physical system. Orbital stability provides upper limits for the masses of the transiting companions that are in the planetary regime. This paper describes a non-parametric technique for quantifying the statistical significance of TTVs based on the correlation of two TTV data sets. We apply this method to an analysis of the transit timing variations of two stars with multiple transiting planet candidates identified by Kepler. We confirm four transiting planets in two multiple planet systems based on their TTVs and the constraints imposed by dynamical stability. An additional three candidates in these same systems are not confirmed as planets, but are likely to be validated as real planets once further observations and analyses are possible. If all were confirmed, these systems would be near 4:6:9 and 2:4:6:9 period commensurabilities. Our results demonstrate that TTVs provide a powerful tool for confirming transiting planets, including low-mass planets and planets around faint stars for which Doppler follow-up is not practical with existing facilities. Continued Kepler observations will dramatically improve the constraints on the planet masses and orbits and provide sensitivity for detecting additional non-transiting planets. If Kepler observations were extended to eight years, then a similar analysis could likely confirm systems with multiple closely spaced, small transiting planets in or near the habitable zone of solar-type stars.

  2. The time scale for the transition to turbulence in a high Reynolds number, accelerated flow

    International Nuclear Information System (INIS)

    Robey, H.F.; Zhou Ye; Buckingham, A.C.; Keiter, P.; Remington, B.A.; Drake, R.P.

    2003-01-01

    An experiment is described in which an interface between materials of different density is subjected to an acceleration history consisting of a strong shock followed by a period of deceleration. The resulting flow at this interface, initiated by the deposition of strong laser radiation into the initially well characterized solid materials, is unstable to both the Richtmyer-Meshkov (RM) and Rayleigh-Taylor (RT) instabilities. These experiments are of importance in their ability to access a difficult experimental regime characterized by very high energy density (high temperature and pressure) as well as large Reynolds number and Mach number. Such conditions are of interest, for example, in the study of the RM/RT induced mixing that occurs during the explosion of a core-collapse supernova. Under these experimental conditions, the flow is in the plasma state and given enough time will transition to turbulence. By analysis of the experimental data and a corresponding one-dimensional numerical simulation of the experiment, it is shown that the Reynolds number is sufficiently large (Re>10 5 ) to support a turbulent flow. An estimate of three key turbulence length scales (the Taylor and Kolmogorov microscales and a viscous diffusion scale), however, shows that the temporal duration of the present flow is insufficient to allow for the development of a turbulent inertial subrange. A methodology is described for estimating the time required under these conditions for the development of a fully turbulent flow

  3. Marine Radioactivity Studies in the Suez Canal, Part I: Hydrodynamics and Transit Times

    Science.gov (United States)

    Abril, J. M.; Abdel-Aal, M. M.

    2000-04-01

    This paper describes work carried out under the IAEA Project EGY/07/002 to study the dispersion of radioactive material in the Suez Canal. This effort is linked with the increased public concern about radiation safety through this important trade route. To follow the fate of radioactive wastes along this waterway, we had to solve the hydrodynamics of the water, governed mainly by tides, atmospheric forcing and the drift currents produced by horizontal salinity gradients and by differences in mean sea level (MSL) at the two entrances of the Canal. The hydrodynamics has been studied using both 1-D and 2-D modelling approaches, and a reasonable calibration has been possible from the data set prepared with the collaboration of the Suez Canal Authority. Dispersion of conservative pollutants has been preliminarily studied by using a 1-D-Gaussian approach. Thus, we are computing the path of the plumes and the time evolution of concentrations for different scenarios of discharges and under different seasonal conditions. The transit times can vary enormously during the year, ranging from a few days to several months, depending on the differences in MSL at the two entrances of the Canal.

  4. Increasing accuracy of pulse transit time measurements by automated elimination of distorted photoplethysmography waves.

    Science.gov (United States)

    van Velzen, Marit H N; Loeve, Arjo J; Niehof, Sjoerd P; Mik, Egbert G

    2017-11-01

    Photoplethysmography (PPG) is a widely available non-invasive optical technique to visualize pressure pulse waves (PWs). Pulse transit time (PTT) is a physiological parameter that is often derived from calculations on ECG and PPG signals and is based on tightly defined characteristics of the PW shape. PPG signals are sensitive to artefacts. Coughing or movement of the subject can affect PW shapes that much that the PWs become unsuitable for further analysis. The aim of this study was to develop an algorithm that automatically and objectively eliminates unsuitable PWs. In order to develop a proper algorithm for eliminating unsuitable PWs, a literature study was conducted. Next, a '7Step PW-Filter' algorithm was developed that applies seven criteria to determine whether a PW matches the characteristics required to allow PTT calculation. To validate whether the '7Step PW-Filter' eliminates only and all unsuitable PWs, its elimination results were compared to the outcome of manual elimination of unsuitable PWs. The '7Step PW-Filter' had a sensitivity of 96.3% and a specificity of 99.3%. The overall accuracy of the '7Step PW-Filter' for detection of unsuitable PWs was 99.3%. Compared to manual elimination, using the '7Step PW-Filter' reduces PW elimination times from hours to minutes and helps to increase the validity, reliability and reproducibility of PTT data.

  5. Distribution and transit times of plutonium-bearing particles throughout the channel

    International Nuclear Information System (INIS)

    Boust, D.; Colin, C.; Leclerc, G.; Baron, Y.

    1997-01-01

    The distribution and dispersive behaviour of Pu isotopes in the sediments of the Channel is presented and elucidated. The Pu concentrations vary by a factor of 70 and 1000, for 239,240 Pu and 238 Pu, respectively, which is consistent with the relative contributions of source terms (fallout versus industrial) and expected grain-size modulations. The Pu isotopic ratios ( 238 Pu/ 239,240 Pu) increase from the western approaches of the Channel (0.05 or lower: atmospheric fallout) to 0.9 in the Central Channel (industrial input), then slightly decrease in the Eastern Channel. A relation between the Pu isotopic ratios and the passing time at Cherbourg enables us to estimate the transit time of sediments from Cherbourg to any sampling station. Average velocities derived from these data range between some km a -1 to some tens of km a -1 . They are ca 2 orders of magnitude lower than residual tide currents responsible for the dispersion of conservative elements (1000 km a -1 ), thus suggesting that the sediment movements occur only significantly during paroxysmic events. This approach gives access to the dynamics of the dispersion of Pu associated to these sediments and set new constraints to numerical models. (author)

  6. Position, Energy, and Transit Time Distributions in a Hemispherical Deflector Analyzer with Position Sensitive Detector

    Directory of Open Access Journals (Sweden)

    Omer Sise

    2015-01-01

    Full Text Available Practical analytic equations, for the ideal field, and numerical results from SIMION simulations, for the fringing field, are presented for the exit radius rπ and transit time tπ of electrons in a hemispherical deflector analyzer (HDA over a wide range of analyzer parameters. Results are presented for a typically dimensioned HDA with mean radius R-=101.6 mm and interradial separation ΔR=R2-R1=58.4 mm able to accommodate a 40 mm diameter position sensitive detector (PSD. Results for three different entry positions R0 are compared: R0=R- (the conventional central entry and two displaced (paracentric entries: R0=82.55 mm and R0=116 mm. Exit spreads Δrπ, Δtπ and base energy resolution ΔEB are computed for HDA pass energies E0=10, 100, 500, and 1000 eV, entry aperture sizes Δr0≤1.5 mm, entry angular spreads |αmax|≤5°, and an electron beam with relative energy spread δE/E0≤0.4%. Overall, under realistic conditions, both paracentric entries demonstrate near ideal field behavior and clear superiority over the conventional entry at R0=R-. The R0=82.55 mm entry has better absolute energy and time spread resolutions, while the R0=116 mm has better relative energy resolutions, both offering attractive alternatives for time-of-flight and coincidence applications where both energy and timing resolutions are important.

  7. A study on the pulmonary mean transit time and the pulmonary blood volume by RI-cardiogram

    International Nuclear Information System (INIS)

    Ushio, Norio

    1987-01-01

    The pulmonary mean transit time and the pulmonary blood volume in cases of cardio-pulmonary disease were measured using Giuntini's method which is considered the most appropriate among radiocardiographic methods. The errors in this method were confirmed to be almost negligible. The results obtained were as follows: 1) The pulmonary mean transit time was related to the systemic mean transit time and markedly prolonged in left heart failure. On the other hand, it was markedly shortened in some cases of chronic pulmonary disease, particularly pulmonary emphysema. 2) The pulmonary blood volume tended to increase in left heart disorders and mitral valve disease and tended to decrease in the chronic pulmonary disease. The decrease was conspicuous particularly in some cases of pulmonary emphysema. 3) A structural change of the pulmonary vascular system in the chronic pulmonary disease appeared to bring about shortening of the pulmonary mean transit time and a decrease in the pulmonary blood volume. The pathophysiology of cardio-pulmonary disease can be more clarified by the RI-cardiogram used in this study, in which the pulmonary mean transit time and the pulmonary blood volume are used as the indicator. (author)

  8. Development of the Connecticut Airway Risk Evaluation (CARE) system to improve handoff communication in pediatric patients with tracheotomy.

    Science.gov (United States)

    Lawrason Hughes, Amy; Murray, Nicole; Valdez, Tulio A; Kelly, Raeanne; Kavanagh, Katherine

    2014-01-01

    National attention has focused on the importance of handoffs in medicine. Our practice during airway patient handoffs is to communicate a patient-specific emergency plan for airway reestablishment; patients who are not intubatable by standard means are at higher risk for failure. There is currently no standard classification system describing airway risk in tracheotomized patients. To introduce and assess the interrater reliability of a simple airway risk classification system, the Connecticut Airway Risk Evaluation (CARE) system. We created a novel classification system, the CARE system, based on ease of intubation and the need for ventilation: group 1, easily intubatable; group 2, intubatable with special equipment and/or maneuvers; group 3, not intubatable. A "v" was appended to any group number to indicate the need for mechanical ventilation. We performed a retrospective medical chart review of patients aged 0 to 18 years who were undergoing tracheotomy at our tertiary care pediatric hospital between January 2000 and April 2011. INTERVENTIONS Each patient's medical history, including airway disease and means of intubation, was reviewed by 4 raters. Patient airways were separately rated as CARE groups 1, 2, or 3, each group with or without a v appended, as appropriate, based on the available information. After the patients were assigned to an airway group by each of the 4 raters, the interrater reliability was calculated to determine the ease of use of the rating system. We identified complete data for 155 of 169 patients (92%), resulting in a total of 620 ratings. Based on the patient's ease of intubation, raters categorized tracheotomized patients into group 1 (70%, 432 of 620); group 2 (25%, 157 of 620); or group 3 (5%, 29 of 620), each with a v appended if appropriate. The interrater reliability was κ = 0.95. We propose an airway risk classification system for tracheotomized patients, CARE, that has high interrater reliability and is easy to use and

  9. Time-Resolved Studies of Laser-Induced Phase Transitions in Gallium Arsenide

    Science.gov (United States)

    Siegal, Yakir

    This thesis describes a series of time-resolved experiments of the linear and nonlinear optical properties of GaAs during laser-induced phase transitions. The first set of experiments consists of a direct determination of the behavior of the linear dielectric constant at photon energies of 2.2 eV and 4.4 eV following excitation of the sample with 1.9-eV, 70-fs laser pulses spanning a fluence range from 0 to 2.5 kJ/m^2. The results from this set of experiments were used to extract the behavior of the second-order optical susceptibility from second-harmonic generation measurements made under identical excitation conditions. These experiments are unique because they provide explicit information on the behavior of intrinsic material properties--the linear and nonlinear optical susceptibilities--during laser-induced phase transitions in semiconductors without the ambiguities in interpretation that are generally inherent in reflectivity and second-harmonic generation measurements. The dielectric constant data indicate a drop in the average bonding-antibonding splitting of GaAs following the laser pulse excitation. This behavior leads to a collapse of the band-gap on a picosecond time scale for excitation at fluences near the damage threshold of 1.0 kJ/m ^2 and even faster at higher excitation fluences. The changes in the electronic band structure result from a combination of electronic screening by the excited free carriers and structural deformation of the lattice caused by the destabilization of the covalent bonds. The behavior of the second-order susceptibility shows that the material loses long-range order before the average bonding-antibonding splitting, which is more sensitive to short-range structure, changes significantly. Loss of long-range order and a drop of more than 2 eV in the average bonding-antibonding splitting are seen even at fluences below the damage threshold, a regime in which the laser-induced changes are reversible.

  10. Laminar microvascular transit time distribution in the mouse somatosensory cortex revealed by Dynamic Contrast Optical Coherence Tomography.

    Science.gov (United States)

    Merkle, Conrad W; Srinivasan, Vivek J

    2016-01-15

    The transit time distribution of blood through the cerebral microvasculature both constrains oxygen delivery and governs the kinetics of neuroimaging signals such as blood-oxygen-level-dependent functional Magnetic Resonance Imaging (BOLD fMRI). However, in spite of its importance, capillary transit time distribution has been challenging to quantify comprehensively and efficiently at the microscopic level. Here, we introduce a method, called Dynamic Contrast Optical Coherence Tomography (DyC-OCT), based on dynamic cross-sectional OCT imaging of an intravascular tracer as it passes through the field-of-view. Quantitative transit time metrics are derived from temporal analysis of the dynamic scattering signal, closely related to tracer concentration. Since DyC-OCT does not require calibration of the optical focus, quantitative accuracy is achieved even deep in highly scattering brain tissue where the focal spot degrades. After direct validation of DyC-OCT against dilution curves measured using a fluorescent plasma label in surface pial vessels, we used DyC-OCT to investigate the transit time distribution in microvasculature across the entire depth of the mouse somatosensory cortex. Laminar trends were identified, with earlier transit times and less heterogeneity in the middle cortical layers. The early transit times in the middle cortical layers may explain, at least in part, the early BOLD fMRI onset times observed in these layers. The layer-dependencies in heterogeneity may help explain how a single vascular supply manages to deliver oxygen to individual cortical layers with diverse metabolic needs. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. TRANSIT TIMING VARIATION MEASUREMENTS OF WASP-12b AND QATAR-1b: NO EVIDENCE OF ADDITIONAL PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Karen A.; Stassun, Keivan G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Kielkopf, John F. [Department of Physics and Astronomy, University of Louisville, Louisville, KY 40292 (United States)

    2017-02-01

    WASP-12b and Qatar-1b are transiting hot Jupiters for which previous works have suggested the presence of transit timing variations (TTVs) indicative of additional bodies in these systems—an Earth-mass planet in WASP-12 and a brown-dwarf mass object in Qatar-1. Here, we present 23 new WASP-12b and 18 new Qatar-1b complete (or nearly complete) transit observations. We perform global system fits to all of our light curves for each system, as well as RV and stellar spectroscopic parameters from the literature. The global fits provide refined system parameters and uncertainties for each system, including precise transit center times for each transit. The transit model residuals of the combined and five minute binned light curves have an rms of 183 and 255 parts per million (ppm) for WASP-12b and Qatar-1b, respectively. Most of the WASP-12b system parameter values from this work are consistent with values from previous studies, but have ∼40%–50% smaller uncertainties. Most of the Qatar-1b system parameter values and uncertainties from this work are consistent with values recently reported in the literature. We find no convincing evidence for sinusoidal TTVs with a semi-amplitude of more than ∼35 and ∼25 s in the WASP-12b and Qatar-1b systems, respectively.

  12. The 1874 Transit of Venus and the Popularisation of Astronomy in the USA as Reflected in the New York Times

    Science.gov (United States)

    Cottam, Stella; Orchiston, Wayne; Stephenson, Richard

    Given uncertainty surrounding the true value of the astronomical unit following the 1761 and 1769 transits of Venus the next transit, in 1874, offered hope for a substantial refinement in the value of this fundamental yardstick of Solar System astronomy. Part of the reason for this successful anticipated outcome was that both photography and spectroscopy would be applied to a transit of Venus for the first time. Consequently expectations were high, and this unusual event enjoyed a high public profile, thanks to frequent articles published in newspapers and in magazines. Because of the importance of this transit, many nations dispersed expeditions to Asia, the Pacific and the Australia-New Zealand region where the entire event could be seen. The USA sent out eight transit parties to this part of the world, and their activities and results, along with those of other nations' transit parties, were widely reported back home. In this paper we focus on the US expeditions, and the ways in which their activities were reported on back in the USA through the pages of the New York Times.

  13. Automatic determination of L/H transition times in DIII-D through a collaborative distributed environment

    International Nuclear Information System (INIS)

    Farias, G.; Vega, J.; González, S.; Pereira, A.; Lee, X.; Schissel, D.; Gohil, P.

    2012-01-01

    Highlights: ► An automatic predictor of L/H transition times has been implemented for the DIII-D tokamak. ► The system predicts the transition combining two techniques: a morphological pattern recognition algorithm and a support vector machines multi-layer model. ► The predictor is employed within a collaborative distributed computing environment. The system is trained remotely in the Ciemat computer cluster and operated on the DIII-D site. - Abstract: An automatic predictor of L/H transition times has been implemented for the DIII-D tokamak. The system predicts the transition combining two techniques: A morphological pattern recognition algorithm, which estimates the transition based on the waveform of a Dα emission signal, and a support vector machines multi-layer model, which predicts the L/H transition using a non-parametric model. The predictor is employed within a collaborative distributed computing environment. The system is trained remotely in the Ciemat computer cluster and operated on the DIII-D site.

  14. Transit Time Flowmetry in Coronary Surgery-An Important Tool in Graft Verification

    Directory of Open Access Journals (Sweden)

    Emir Mujanović

    2007-08-01

    Full Text Available The aim of this study was to analyze the Transit time flow measurement (TTFM experience in the first 1000 CABG operations. First 1000 patients had coronary artery bypass grafting (CABG performed in Cardiovascular Clinic, University Clinical Centre Tuzla, Bosnia and Herzegovina, between September, 1998 and September, 2003. CABG without use of cardio-pulmonary bypass (CPB-(OPCAB was used as the preferential surgical method both because this method is reported to have equal or better results than CABG with use of CPB (ONCAB, and because of the significant cost savings realized. TTFM was routinely used in all grafts as a quality assurance measure. Criteria for a poor functioning graft were: low mean flow (MF, pul-satility index (PI above 5 and a poor diastolic flow pattern. When no reversible cause of poor TTFM results were identified the graft was revised. A total of 1394 grafts in OPCAB group and 1478 in ONCAB group were performed. A total of 38 grafts (2,72% in 37 patients (7,07% were revised in OPCAB group, and 26 grafts (1,75% in 26 patients (5,45% in ONCAB group. 1 patient in OPCAB group needed 2 graft revisions. Graft revisions were more common in OPCAB, but with no significant difference (p=0,1035. The most frequently revised graft was LAD graft in both groups. Although the percentage of grafts revised are relatively low, it is still very important to record TTFM. More than 5% of patients in both groups needed graft revision. Although TTFM does not guarantee that grafts will stay open for a prolonged period of time we certainly believe that grafts that are occluded at the time of surgery will continue to stay occluded. TTFM is especially critical in OPCAB surgery where the technical challenge of grafting is higher then in ONCAB.

  15. Water deficit severity during berry development alters timing of dormancy transitions in wine grape cultivar Malbec

    Science.gov (United States)

    The objective of this study was to test the hypothesis that vine water stress during the growing season can lengthen the dormancy cycle by inducing earlier transition into endodormancy. A bud forcing assay was used to compare the dormancy transitions of field-grown ‘Malbec’ grapevines that had been ...

  16. Stochastic Stability for Time-Delay Markovian Jump Systems with Sector-Bounded Nonlinearities and More General Transition Probabilities

    Directory of Open Access Journals (Sweden)

    Dan Ye

    2013-01-01

    Full Text Available This paper is concerned with delay-dependent stochastic stability for time-delay Markovian jump systems (MJSs with sector-bounded nonlinearities and more general transition probabilities. Different from the previous results where the transition probability matrix is completely known, a more general transition probability matrix is considered which includes completely known elements, boundary known elements, and completely unknown ones. In order to get less conservative criterion, the state and transition probability information is used as much as possible to construct the Lyapunov-Krasovskii functional and deal with stability analysis. The delay-dependent sufficient conditions are derived in terms of linear matrix inequalities to guarantee the stability of systems. Finally, numerical examples are exploited to demonstrate the effectiveness of the proposed method.

  17. Total and segmental colon transit time in constipated children assessed by scintigraphy with 111In-DTPA given orally.

    Science.gov (United States)

    Vattimo, A; Burroni, L; Bertelli, P; Messina, M; Meucci, D; Tota, G

    1993-12-01

    Serial colon scintigraphy using 111In-DTPA (2 MBq) given orally was performed in 39 children referred for constipation, and the total and segmental colon transit times were measured. The bowel movements during the study were recorded and the intervals between defecations (ID) were calculated. This method proved able to identify children with normal colon morphology (no. = 32) and those with dolichocolon (no. = 7). Normal children were not included for ethical reasons and we used the normal range determined by others using x-ray methods (29 +/- 4 hours). Total and segmental colon transit times were found to be prolonged in all children with dolichocolon (TC: 113.55 +/- 41.20 hours; RC: 39.85 +/- 26.39 hours; LC: 43.05 +/- 18.30 hours; RS: 30.66 +/- 26.89 hours). In the group of children with a normal colon shape, 13 presented total and segmental colon transit times within the referred normal value (TC: 27.79 +/- 4.10 hours; RC: 9.11 +/- 2.53 hours; LC: 9.80 +/- 3.50 hours; RS: 8.88 +/- 4.09 hours) and normal bowel function (ID: 23.37 +/- 5.93 hours). In the remaining children, 5 presented prolonged retention in the rectum (RS: 53.36 +/- 29.66 hours), and 14 a prolonged transit time in all segments. A good correlation was found between the transit time and bowel function. From the point of view of radiation dosimetry, the most heavily irradiated organs were the lower large intestine and the ovaries, and the level of radiation burden depended on the colon transit time. We can conclude that the described method results safe, accurate and fully diagnostic.

  18. Esophageal transit time in patients with chagasic megaesophagus: Lack of linear correlation between dysphagia and grade of dilatation.

    Science.gov (United States)

    Martins, Paula; Ferreira, Cid Sergio; Cunha-Melo, José Renan

    2018-03-01

    The aim of this study was to determine the esophageal transit time in control individuals and in chagasic patients with or without megaesophagus.A total of 148 patients were allocated in 6 groups according to serological diagnostic of Chagas disease and the degree of esophageal dilatation: A, control healthy individuals (n = 34, 22.9%); B, indeterminate form (n = 23, 15.5%); C, megaesophagus I (n = 37, 25.0%); D, megaesophagus II (n = 19, 12.8%); E, megaesophagus III (n = 21, 14.2%); and F, megaesophagus IV (n = 14, 9.5%). After 8-hour fasting, patients were asked to swallow 75 mL of barium sulfate solution. x-Rays were obtained after 8, 30, 60, and 90 seconds, 5, 10, 30, 60, and 90 minutes, 2, 6, 12, 24 hours, and at every 12 hours until no more contrast was seen in the esophagus. This was the transit time.The transit time varied from 8 seconds to 36 hours (median = 90 seconds). A linear correlation was observed between transit time and megaesophagus grade: 8 seconds in groups A and B, 5 minutes in C, 30 minutes in D, 2 hours in E, and 9:15 hours in F. Dysphagia was not reported by 60 of 114 (52.6%) patients with positive serological tests for Chagas disease (37/91-40.7%-of patients with megaesophagus I-IV grades). The esophageal transit time increased with the grade of megaesophagus.The esophageal transit time has a direct correlation with the grade of megaesophagus; dysphagia complaint correlates with the grade of megaesophagus. However, many patients with megaesophagus do not report dysphagia.

  19. The effects of transit time heterogeneity on brain oxygenation during rest and functional activation

    Science.gov (United States)

    Rasmussen, Peter M; Jespersen, Sune N; Østergaard, Leif

    2015-01-01

    The interpretation of regional blood flow and blood oxygenation changes during functional activation has evolved from the concept of ‘neurovascular coupling', and hence the regulation of arteriolar tone to meet metabolic demands. The efficacy of oxygen extraction was recently shown to depend on the heterogeneity of capillary flow patterns downstream. Existing compartment models of the relation between tissue metabolism, blood flow, and blood oxygenation, however, typically assume homogenous microvascular flow patterns. To take capillary flow heterogeneity into account, we modeled the effect of capillary transit time heterogeneity (CTH) on the ‘oxygen conductance' used in compartment models. We show that the incorporation of realistic reductions in CTH during functional hyperemia improves model fits to dynamic blood flow and oxygenation changes acquired during functional activation in a literature animal study. Our results support earlier observations that oxygen diffusion properties seemingly change during various physiologic stimuli, and posit that this phenomenon is related to parallel changes in capillary flow patterns. Furthermore, our results suggest that CTH must be taken into account when inferring brain metabolism from changes in blood flow- or blood oxygenation-based signals . PMID:25492112

  20. Densities and eccentricities of 139 Kepler planets from transit time variations

    Energy Technology Data Exchange (ETDEWEB)

    Hadden, Sam; Lithwick, Yoram [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States)

    2014-05-20

    We extract densities and eccentricities of 139 sub-Jovian planets by analyzing transit time variations (TTVs) obtained by the Kepler mission through Quarter 12. We partially circumvent the degeneracies that plague TTV inversion with the help of an analytical formula for the TTV. From the observed TTV phases, we find that most of these planets have eccentricities of the order of a few percent. More precisely, the rms eccentricity is 0.018{sub −0.004}{sup +0.005}, and planets smaller than 2.5 R {sub ⊕} are around twice as eccentric as those bigger than 2.5 R {sub ⊕}. We also find a best-fit density-radius relationship ρ ≈ 3 g cm{sup –3} × (R/3 R {sub ⊕}){sup –2.3} for the 56 planets that likely have small eccentricity and hence small statistical correction to their masses. Many planets larger than 2.5 R {sub ⊕} are less dense than water, implying that their radii are largely set by a massive hydrogen atmosphere.

  1. Men, maternity and moral residue: negotiating the moral demands of the transition to first time fatherhood.

    Science.gov (United States)

    Ives, Jonathan

    2014-09-01

    This article discusses men's transition to first time fatherhood, with a focus on the way they recognise various in-tension moral demands and negotiate an appropriate role for themselves. The findings are taken from a longitudinal study, drawing on elements of grounded theory, comprising a series of face-to-face and telephone interviews with 11 men over a 9-month period from the 12(th) week of pregnancy to 8 weeks after the birth. The analysis focuses on men's feelings and experience of exclusion and participation, and their response and reaction to that experience. The findings present two descriptive themes, 'on the inside looking in' and 'present but not participating', followed by third theme 'deference and support: a moral response' that exposes the dilemmatic nature of men's experience and explains the participants' apparent acceptance of being less involved. The discussion explores the concept of moral residue, arguing that while deference and support may be an appropriate role for fathers in the perinatal period it may also be a compromise that leads to feelings of uncertainty and frustration, which is a consequence of being in a genuinely dilemmatic situation. © 2014 The Author. Sociology of Health & Illness published by John Wiley & Sons Ltd on behalf of Foundation for Sociology of Health and Illness (SHIL).

  2. Minimal cardiac transit-times in the diagnosis of heart disease

    International Nuclear Information System (INIS)

    Freundlieb, C.; Vyska, K.; Hoeck, A.; Schicha, H.; Becker, V.; Feinendegen, L.E.

    1976-01-01

    Using Indium-113m and the Gamma Retina V (Fucks-Knipping Camera), the minimal cardiac transit times (MTTs) were measured radiocardiographically from the right auricle to the aortic root. This analysis served to determine the relation between stroke volume and the segment volume of the part of circulation between the right auricle and the aortic root. In 39 patients with myocardial insufficiency of different clinical degree the effectiveness of digitalization was, up to a period of 5 years, measured by means of the volume relation mentioned above. The following conclusions can be drawn from the results: digitalization of patients with myocardial insufficiency leads to an improvement of the impaired relation of central volumes. In patients with diminished cardiac reserve the improvement is drastic and often results in a nearly complete normalization. The data remain constant during therapy even for an observation period of 5 years. Digitalization of patients with congestive heart failure only leads to a partial improvement. In contrast to patients with diminished cardiac reserve this effect is temporary. The different behaviour of the relation between stroke volume and segment volume in patients with diminished cardiac reserve and congestive heart failure under prolonged administration of digitalis points to the necessity of treatment with digitalis in the early stage of myocardial disease. (orig.) [de

  3. Colonic transit time and pressure based on Bernoulli’s principle

    Science.gov (United States)

    Uno, Yoshiharu

    2018-01-01

    Purpose Variations in the caliber of human large intestinal tract causes changes in pressure and the velocity of its contents, depending on flow volume, gravity, and density, which are all variables of Bernoulli’s principle. Therefore, it was hypothesized that constipation and diarrhea can occur due to changes in the colonic transit time (CTT), according to Bernoulli’s principle. In addition, it was hypothesized that high amplitude peristaltic contractions (HAPC), which are considered to be involved in defecation in healthy subjects, occur because of cecum pressure based on Bernoulli’s principle. Methods A virtual healthy model (VHM), a virtual constipation model and a virtual diarrhea model were set up. For each model, the CTT was decided according to the length of each part of the colon, and then calculating the velocity due to the cecum inflow volume. In the VHM, the pressure change was calculated, then its consistency with HAPC was verified. Results The CTT changed according to the difference between the cecum inflow volume and the caliber of the intestinal tract, and was inversely proportional to the cecum inflow volume. Compared with VHM, the CTT was prolonged in the virtual constipation model, and shortened in the virtual diarrhea model. The calculated pressure of the VHM and the gradient of the interlocked graph were similar to that of HAPC. Conclusion The CTT and HAPC can be explained by Bernoulli’s principle, and constipation and diarrhea may be fundamentally influenced by flow dynamics. PMID:29670388

  4. Effect of intravenous amino acids on interdigestive antroduodenal motility and small bowel transit time.

    Science.gov (United States)

    Gielkens, H A; van den Biggelaar, A; Vecht, J; Onkenhout, W; Lamers, C B; Masclee, A A

    1999-02-01

    Patients on total parenteral nutrition have an increased risk of developing gallstones because of gall bladder hypomotility. High dose amino acids may prevent biliary stasis by stimulating gall bladder emptying. To investigate whether intravenous amino acids also influence antroduodenal motility. Eight healthy volunteers received, on three separate occasions, intravenous saline (control), low dose amino acids (LDA), or high dose amino acids (HDA). Antroduodenal motility was recorded by perfusion manometry and duodenocaecal transit time (DCTT) using the lactulose breath hydrogen test. DCTT was significantly prolonged during LDA and HDA treatment compared with control. The interdigestive motor pattern was maintained and migrating motor complex (MMC) cycle length was significantly reduced during HDA compared with control and LDA due to a significant reduction in phase II duration. Significantly fewer phase IIIs originated in the gastric antrum during LDA and HDA compared with control. Duodenal phase II motility index was significantly reduced during HDA, but not during LDA, compared with control. Separate intravenous infusion of high doses of amino acids in healthy volunteers: (1) modulates interdigestive antroduodenal motility; (2) shortens MMC cycle length due to a reduced duration of phase II with a lower contractile incidence both in the antrum and duodenum (phase I remains unchanged whereas the effect on phase III is diverse: in the antrum phase III is suppressed and in the duodenum the frequency is increased); and (3) prolongs interdigestive DCTT.

  5. Scintigraphic determination of the effect of metoclopramide and morphine on small intestinal transit time

    Energy Technology Data Exchange (ETDEWEB)

    Prokop, E.K.; Caride, V.J.; Winchenbach, K.; Troncale, F.J.; McCallum, R.W.

    1988-01-01

    To determine if a scintigraphic method could detect pharmacologic changes in small intestinal transit time (SITT), 10 male volunteers were studied at baseline and after intravenously administered metoclopramide (10 mg) and morphine (8 mg). Five of these volunteers were studied with the hydrogen breath test method for comparison. For each of the scintigraphic studies, the volunteers were positioned supine under a large-field-of-view gamma camera after ingesting an isosmotic lactulose solution containing 99mtechnetium-diethylenetriaminepentaacetic acid (DTPA). Data were collected and stored in a computer. Both gastric emptying and SITT were determined. SITT was 81 +/- 11 min (mean +/- S.E.M.; N = 10) during baseline studies, was decreased significantly to 50 +/- 6 min (N = 10; P less than 0.01) after metoclopramide, and was increased significantly to 161 +/- 15 min (N = 8; P less than 0.01) after morphine. Baseline mean values were 86.3 +/- 15 min (N = 15) for the hydrogen breath tests, 47 +/- 8 min (N = 5) for metoclopramide, and 183 +/- 16 min (N = 5) for morphine. For gastric emptying, there was no significant difference in percentage emptying at 1 hr for baseline and metochopramide (82 +/- 5% vs. 88 +/- 4%). Morphine prolonged gastric emptying at 1 hr to 63 +/- 8%. We conclude that the scintigraphic method for measuring SITT permits accurate investigation of the pharmacologic effects on intestinal motility and, in addition, may be a useful research and clinical method for SITT determination.

  6. [Alcohol drinking in the time of political transition in Poland. Report of the National Health Programme ].

    Science.gov (United States)

    Moskalewicz, Jacek; Zulewska-Sak, Justyna

    2003-01-01

    The National Health Programme was adopted in Poland in the mid-1990s. It consists of 18 targets including target 4 that calls for diminishing alcohol consumption and changing its structure as well as limiting health harms associated with alcohol. The programme is being monitored on bi-annual basis. The monitoring covers a level of alcohol consumption and associated harm including trends in mortality and morbidity as well as in road accidents in 1990-2001 period. During the period in point, particularly in the beginning of the transition alcohol consumption increased at least by one third reaching 10-11 litres of pure ethanol per capita, mostly due to sudden disruption of the alcohol control system and high tide of unrecorded supply. Currently, the consumption is estimated to be 9.5-10.0 litres with 30% share of the unrecorded. During last decade recorded morbidity due to mental disorders associated with alcohol increased by 80% and 60% respectively in out- and in-patient system while mortality rates almost doubled. Male mortality due to liver diseases increased by 50% while that of women remained relatively flat. In last few years, alcohol related mortality tended to decline slightly parallel to consumption trends. Significant improvement has been achieved in prevention of drunken diving. The number of deaths in alcohol related road accidents decreased two fold while a rate of drunken crashes per 1000 vehicles dropped three times.

  7. VizieR Online Data Catalog: Kepler-80 transit timing observations (MacDonald+, 2016)

    Science.gov (United States)

    MacDonald, M. G.; Ragozzine, D.; Fabrycky, D. C.; Ford, E. B.; Holman, M. J.; Isaacson, H. T.; Lissauer, J. J.; Lopez, E. D.; Mazeh, T.; Rogers, L.; Rowe, J. F.; Steffen, J. H.; Torres, G.

    2017-05-01

    Kepler-80 was observed photometrically by the Kepler Space Telescope. We had access to several sets of Transit Timing (TT) measurements, including the publicly available data from Rowe & Thompson (arXiv:1504.00707) and Mazeh et al. 2013 (Cat. J/ApJS/208/16). We also had the updated long-cadence TT estimates from the Mazeh group (Holczer et al. 2016, Cat. J/ApJS/225/9) and short-cadence TT data from both co-authors JR and DF. These were all measured using similar methods (see Mazeh et al. 2013, Cat. J/ApJS/208/16) and had no major differences. Spectra were taken of Kepler-80 by Keck and McDonald Observatories, and these spectra and preliminary interpretations are available on the Kepler Community Follow-up Observing Program (CFOP) website (https://cfop.ipac.caltech.edu). We acquired an 1800s high-resolution spectrum with the Keck I telescope and the High Resolution Echelle Spectrometer (HIRES) on 2011 July 20. The standard California Planet Search setup and data reduction of HIRES was used, resulting in a S/N of 35 at 5500Å. The C2 decker, with dimensions of 0.87''*14'', was used to allow a resolution of ~60000 and sky subtraction. (5 data files).

  8. A novel Ka-band coaxial transit-time oscillator with a four-gap buncher

    Energy Technology Data Exchange (ETDEWEB)

    Song, Lili; He, Juntao; Ling, Junpu [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2015-05-15

    A novel Ka-band coaxial transit-time oscillator (TTO) with a four-gap buncher is proposed and investigated. Simulation results show that an output power of 1.27 GW and a frequency of 26.18 GHz can be achieved with a diode voltage of 447 kV and a beam current of 7.4 kA. The corresponding power efficiency is 38.5%, and the guiding magnetic field is 0.6 T. Studies and analysis indicate that a buncher with four gaps can modulate the electron beam better than the three-gap buncher in such a Ka-band TTO. Moreover, power efficiency increases with the coupling coefficient between the buncher and the extractor. Further simulation demonstrates that power efficiency can reach higher than 30% with a guiding magnetic field of above 0.5 T. Besides, the power efficiency exceeds 30% in a relatively large range of diode voltage from 375 kV to 495 kV.

  9. Changes in the bilateral pulse transit time difference with a moving arm.

    Science.gov (United States)

    Jiang, Xinge; Wei, Shoushui; Zheng, Dingchang; Huang, Peng; Liu, Chengyu

    2018-04-20

    Changes of pulse transit time (PTT) induced by arm position were studied for unilateral arm. However, consistency of the PTT changes was not validated for both arm sides. We aimed to quantify the PTT changes between horizontal and non-horizontal positions from right arm and left arm in order to explore the consistency of both arms. Twenty-four normal subjects aged between 21 and 50 (14 male and 10 female) years were enrolled. Left and right radial artery pulses were synchronously recorded from 24 healthy subjects with one arm (left or right) at five angles (90∘, 45∘, 0∘, -45∘ and -90∘) and the other arm at the horizontal level (0∘) for reference. The overall mean PTT changes at the five angles (from 90∘ to -90∘) in the left arm (right as reference) were 16.1, 12.3, -0.5, -2.5 and -2.6 ms, respectively, and in the right arm (left as reference) were 18.0, 12.6, 1.6, -1.6 and -2.0 ms, respectively. Obvious differences were not found in the PTT changes between the two arms (left arm moving or right arm moving) under each of the five different positions (all P> 0.05).

  10. Robust motion artefact resistant circuit for calculation of Mean Arterial Pressure from pulse transit time.

    Science.gov (United States)

    Bhattacharya, Tinish; Gupta, Ankesh; Singh, Salam ThoiThoi; Roy, Sitikantha; Prasad, Anamika

    2017-07-01

    Cuff-less and non-invasive methods of Blood Pressure (BP) monitoring have faced a lot of challenges like stability, noise, motion artefact and requirement for calibration. These factors are the major reasons why such devices do not get approval from the medical community easily. One such method is calculating Blood Pressure indirectly from pulse transit time (PTT) obtained from electrocardiogram (ECG) and Photoplethysmogram (PPG). In this paper we have proposed two novel analog signal conditioning circuits for ECG and PPG that increase stability, remove motion artefacts, remove the sinusoidal wavering of the ECG baseline due to respiration and provide consistent digital pulses corresponding to blood pulses/heart-beat. We have combined these two systems to obtain the PTT and then correlated it with the Mean Arterial Pressure (MAP). The aim was to perform major part of the processing in analog domain to decrease processing load over microcontroller so as to reduce cost and make it simple and robust. We have found from our experiments that the proposed circuits can calculate the Heart Rate (HR) with a maximum error of ~3.0% and MAP with a maximum error of ~2.4% at rest and ~4.6% in motion.

  11. Using Forbush Decreases to Derive the Transit Time of ICMEs Propagating from 1 AU to Mars

    Science.gov (United States)

    Freiherr von Forstner, Johan L.; Guo, Jingnan; Wimmer-Schweingruber, Robert F.; Hassler, Donald M.; Temmer, Manuela; Dumbović, Mateja; Jian, Lan K.; Appel, Jan K.; Čalogović, Jaša.; Ehresmann, Bent; Heber, Bernd; Lohf, Henning; Posner, Arik; Steigies, Christian T.; Vršnak, Bojan; Zeitlin, Cary J.

    2018-01-01

    The propagation of 15 interplanetary coronal mass ejections (ICMEs) from Earth's orbit (1 AU) to Mars (˜1.5 AU) has been studied with their propagation speed estimated from both measurements and simulations. The enhancement of magnetic fields related to ICMEs and their shock fronts causes the so-called Forbush decrease, which can be detected as a reduction of galactic cosmic rays measured on ground. We have used galactic cosmic ray (GCR) data from in situ measurements at Earth, from both STEREO A and STEREO B as well as GCR measurements by the Radiation Assessment Detector (RAD) instrument on board Mars Science Laboratory on the surface of Mars. A set of ICME events has been selected during the periods when Earth (or STEREO A or STEREO B) and Mars locations were nearly aligned on the same side of the Sun in the ecliptic plane (so-called opposition phase). Such lineups allow us to estimate the ICMEs' transit times between 1 and 1.5 AU by estimating the delay time of the corresponding Forbush decreases measured at each location. We investigate the evolution of their propagation speeds before and after passing Earth's orbit and find that the deceleration of ICMEs due to their interaction with the ambient solar wind may continue beyond 1 AU. We also find a substantial variance of the speed evolution among different events revealing the dynamic and diverse nature of eruptive solar events. Furthermore, the results are compared to simulation data obtained from two CME propagation models, namely the Drag-Based Model and ENLIL plus cone model.

  12. Financial Distress Prediction Using Discrete-time Hazard Model and Rating Transition Matrix Approach

    Science.gov (United States)

    Tsai, Bi-Huei; Chang, Chih-Huei

    2009-08-01

    Previous studies used constant cut-off indicator to distinguish distressed firms from non-distressed ones in the one-stage prediction models. However, distressed cut-off indicator must shift according to economic prosperity, rather than remains fixed all the time. This study focuses on Taiwanese listed firms and develops financial distress prediction models based upon the two-stage method. First, this study employs the firm-specific financial ratio and market factors to measure the probability of financial distress based on the discrete-time hazard models. Second, this paper further focuses on macroeconomic factors and applies rating transition matrix approach to determine the distressed cut-off indicator. The prediction models are developed by using the training sample from 1987 to 2004, and their levels of accuracy are compared with the test sample from 2005 to 2007. As for the one-stage prediction model, the model in incorporation with macroeconomic factors does not perform better than that without macroeconomic factors. This suggests that the accuracy is not improved for one-stage models which pool the firm-specific and macroeconomic factors together. In regards to the two stage models, the negative credit cycle index implies the worse economic status during the test period, so the distressed cut-off point is adjusted to increase based on such negative credit cycle index. After the two-stage models employ such adjusted cut-off point to discriminate the distressed firms from non-distressed ones, their error of misclassification becomes lower than that of one-stage ones. The two-stage models presented in this paper have incremental usefulness in predicting financial distress.

  13. Constraints or Preferences? Identifying Answers from Part-time Workers’ Transitions in Denmark, France and the United-Kingdom

    OpenAIRE

    Gash, V.

    2008-01-01

    This article investigates whether women work part-time through preference or constraint and argues that different countries provide different opportunities for preference attainment. It argues that women with family responsibilities are unlikely to have their working preferences met without national policies supportive of maternal employment. Using event history analysis the article tracks part-time workers' transitions to both full-time employment and to labour market drop-out.The article co...

  14. A transit timing analysis with combined ground- and space-based photometry

    Directory of Open Access Journals (Sweden)

    Raetz St.

    2015-01-01

    The CoRoT satellite looks back on six years of high precision photometry of a very high number of stars. Thousands of transiting events are detected from which 27 were confirmed to be transiting planets so far. In my research I search and analyze TTVs in the CoRoT sample and combine the unprecedented precision of the light curves with ground-based follow-up photometry. Because CoRoT can observe transiting planets only for a maximum duration of 150 days the ground-based follow-up can help to refine the ephemeris. Here we present first examples.

  15. Robust Guaranteed Cost Observer Design for Singular Markovian Jump Time-Delay Systems with Generally Incomplete Transition Probability

    Directory of Open Access Journals (Sweden)

    Yanbo Li

    2014-01-01

    Full Text Available This paper is devoted to the investigation of the design of robust guaranteed cost observer for a class of linear singular Markovian jump time-delay systems with generally incomplete transition probability. In this singular model, each transition rate can be completely unknown or only its estimate value is known. Based on stability theory of stochastic differential equations and linear matrix inequality (LMI technique, we design an observer to ensure that, for all uncertainties, the resulting augmented system is regular, impulse free, and robust stochastically stable with the proposed guaranteed cost performance. Finally, a convex optimization problem with LMI constraints is formulated to design the suboptimal guaranteed cost filters for linear singular Markovian jump time-delay systems with generally incomplete transition probability.

  16. TRANSIT TIMING OBSERVATIONS FROM KEPLER. II. CONFIRMATION OF TWO MULTIPLANET SYSTEMS VIA A NON-PARAMETRIC CORRELATION ANALYSIS

    International Nuclear Information System (INIS)

    Ford, Eric B.; Moorhead, Althea V.; Morehead, Robert C.; Fabrycky, Daniel C.; Steffen, Jason H.; Carter, Joshua A.; Fressin, Francois; Holman, Matthew J.; Ragozzine, Darin; Charbonneau, David; Lissauer, Jack J.; Rowe, Jason F.; Borucki, William J.; Bryson, Stephen T.; Burke, Christopher J.; Caldwell, Douglas A.; Welsh, William F.; Allen, Christopher; Batalha, Natalie M.; Buchhave, Lars A.

    2012-01-01

    We present a new method for confirming transiting planets based on the combination of transit timing variations (TTVs) and dynamical stability. Correlated TTVs provide evidence that the pair of bodies is in the same physical system. Orbital stability provides upper limits for the masses of the transiting companions that are in the planetary regime. This paper describes a non-parametric technique for quantifying the statistical significance of TTVs based on the correlation of two TTV data sets. We apply this method to an analysis of the TTVs of two stars with multiple transiting planet candidates identified by Kepler. We confirm four transiting planets in two multiple-planet systems based on their TTVs and the constraints imposed by dynamical stability. An additional three candidates in these same systems are not confirmed as planets, but are likely to be validated as real planets once further observations and analyses are possible. If all were confirmed, these systems would be near 4:6:9 and 2:4:6:9 period commensurabilities. Our results demonstrate that TTVs provide a powerful tool for confirming transiting planets, including low-mass planets and planets around faint stars for which Doppler follow-up is not practical with existing facilities. Continued Kepler observations will dramatically improve the constraints on the planet masses and orbits and provide sensitivity for detecting additional non-transiting planets. If Kepler observations were extended to eight years, then a similar analysis could likely confirm systems with multiple closely spaced, small transiting planets in or near the habitable zone of solar-type stars.

  17. TRANSIT TIMING OBSERVATIONS FROM KEPLER. II. CONFIRMATION OF TWO MULTIPLANET SYSTEMS VIA A NON-PARAMETRIC CORRELATION ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Eric B.; Moorhead, Althea V.; Morehead, Robert C. [Astronomy Department, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL 32611 (United States); Fabrycky, Daniel C. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Carter, Joshua A.; Fressin, Francois; Holman, Matthew J.; Ragozzine, Darin; Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Lissauer, Jack J.; Rowe, Jason F.; Borucki, William J.; Bryson, Stephen T.; Burke, Christopher J.; Caldwell, Douglas A. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Welsh, William F. [Astronomy Department, San Diego State University, San Diego, CA 92182-1221 (United States); Allen, Christopher [Orbital Sciences Corporation/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Buchhave, Lars A., E-mail: eford@astro.ufl.edu [Niels Bohr Institute, Copenhagen University, DK-2100 Copenhagen (Denmark); Collaboration: Kepler Science Team; and others

    2012-05-10

    We present a new method for confirming transiting planets based on the combination of transit timing variations (TTVs) and dynamical stability. Correlated TTVs provide evidence that the pair of bodies is in the same physical system. Orbital stability provides upper limits for the masses of the transiting companions that are in the planetary regime. This paper describes a non-parametric technique for quantifying the statistical significance of TTVs based on the correlation of two TTV data sets. We apply this method to an analysis of the TTVs of two stars with multiple transiting planet candidates identified by Kepler. We confirm four transiting planets in two multiple-planet systems based on their TTVs and the constraints imposed by dynamical stability. An additional three candidates in these same systems are not confirmed as planets, but are likely to be validated as real planets once further observations and analyses are possible. If all were confirmed, these systems would be near 4:6:9 and 2:4:6:9 period commensurabilities. Our results demonstrate that TTVs provide a powerful tool for confirming transiting planets, including low-mass planets and planets around faint stars for which Doppler follow-up is not practical with existing facilities. Continued Kepler observations will dramatically improve the constraints on the planet masses and orbits and provide sensitivity for detecting additional non-transiting planets. If Kepler observations were extended to eight years, then a similar analysis could likely confirm systems with multiple closely spaced, small transiting planets in or near the habitable zone of solar-type stars.

  18. Prolonged transition time between colostrum and mature milk in a bear, the giant panda, Ailuropoda melanoleuca

    OpenAIRE

    Griffiths, Katharine; Rong, Hou; Wang, Hairui; Zhang, Zhihe; Zhang, Tong; Watson, David G.; Burchmore, Richard; Loeffler, I.Kati; Kennedy, Malcolm

    2015-01-01

    Bears produce the most altricial neonates of any placental mammal. We hypothesized that the transition from colostrum to mature milk in bears reflects a temporal and biochemical adaptation for altricial development and immune protection. Comparison of bear milks with milks of other eutherians yielded distinctive protein profiles. Proteomic and metabolomic analysis of serial milk samples collected from six giant pandas showed a prolonged transition from colostrum to main-phase lactation over a...

  19. The QoS Indicators Analysis of Integrated EUHT Wireless Communication System Based on Urban Rail Transit in High-Speed Scenario

    Directory of Open Access Journals (Sweden)

    Xiaoxuan Wang

    2018-01-01

    Full Text Available Nowadays, in urban rail transit systems, train wayside communication system uses Wireless Local Area Network (WLAN as wireless technologies to achieve safety-related information exchange between trains and wayside equipment. However, according to the high speed mobility of trains and the limitations of frequency band, WLAN is unable to meet the demands of future intracity and intercity rail transit. And although the Time Division-Long Term Evolution (TD-LTE technology has high performance compared with WLAN, only 20 MHz bandwidth can be used at most. Moreover, in high-speed scenario over 300 km/h, TD-LTE can hardly meet the future requirement as well. The equipment based on Enhanced Ultra High Throughput (EUHT technology can achieve a better performance in high-speed scenario compared with WLAN and TD-LTE. Furthermore, it allows using the frequency resource flexibly based on 5.8 GHz, such as 20 MHz, 40 MHz, and 80 MHz. In this paper, we set up an EUHT wireless communication system for urban rail transit in high-speed scenario integrated all the traffics of it. An outdoor testing environment in Beijing-Tianjin High-speed Railway is set up to measure the performance of integrated EUHT wireless communication system based on urban rail transit. The communication delay, handoff latency, and throughput of this system are analyzed. Extensive testing results show that the Quality of Service (QoS of the designed integrated EUHT wireless communication system satisfies the requirements of urban rail transit system in high-speed scenario. Moreover, compared with testing results of TD-LTE which we got before, the maximum handoff latency of safety-critical traffics can be decreased from 225 ms to 150 ms. The performance of throughput-critical traffics can achieve 2-way 2 Mbps CCTV and 1-way 8 Mbps PIS which are much better than 2-way 1 Mbps CCTV and 1-way 2 Mbps PIS in TD-LTE.

  20. Usefulness of colon transit time and defecography in patients with chronic constipation

    International Nuclear Information System (INIS)

    Park, Kyoung Seuk; Chung, Jae Joon; Kim, Myung Hyun; Park, Su Mi; Yang, Hee Chul

    2006-01-01

    We wanted to evaluate whether both the colonic transit time (CTT) and defecography are necessary for diagnosing constipated patients, and we also wanted to assess the defecographic findings of patients with outlet obstruction on CTT. Over the recent 3 years, 26 patients (21 women and 5 men, mean age: 59 years) underwent both CTT and defecography because of their chronic constipations or defecation difficulty. The mean interval between the 2 studies was 48 days. Colonoscopy, barium enema and manometry were performed in 22, 8 and all the patients, respectively. On CTT, 13 patients (50.0%) were normal and 13 patients (50.0%) were abnormal; the abnormal results were composed of outlet obstruction (n = 8, 30.8%), outlet obstruction and colon inertia (n = 2, 7.7%), colon inertia (n = 2, 7.7%), and outlet obstruction and hindgut dysfunction (n = 1, 3.8%). On defecography, 6 patients (23.1%) were normal and 20 patients (76.9%) were abnormal; the results were composed of rectocele (n = 8, 30.7%), rectocele and perineal descent syndrome (PDS; n = 4, 15.4%), PDS and rectal intussusception (n = 3, 11.5%), spastic pelvic floor syndrome (SPFS; n = 3, 11.5%), rectocele and SPFS (n = 1, 3.8%), and rectal intussusception (n = 1, 3.8%). Of the 11 patients with outlet obstruction on CTT, rectocele (n = 4, 36.4%), SPFS (n = 1, 9.1%), rectocele and PDS (n = 1, 9.1%), and PDS and rectal intussusception (n = 1, 9.1%) were demonstrated on defecography, except for the 4 normal cases. Both CTT and defecography were necessary for diagnosing the patients with chronic constipation in compensation, and 63.6% of the patients with pelvic outlet obstruction showed an abnormal pelvic defecation function

  1. Correlation Between Timed Barium Esophagogram and Esophageal Transit Scintigraphy Results in Achalasia.

    Science.gov (United States)

    Park, Yoo Mi; Jeon, Han Ho; Park, Jae Jun; Kim, Jie-Hyun; Youn, Young Hoon; Park, Hyojin

    2015-08-01

    Timed barium esophagogram (TBE) and esophageal transit scintigraphy (ETS) have been adopted as useful ways to evaluate achalasia patients. TBE has merit as a simple, non-invasive, and convenient method. The study sought to compare the results of these two tests and verify their usefulness in evaluating treatment response. In addition, we assessed whether TBE could effectively replace ETS through correlation analysis. The medical records of 50 achalasia patients treated between September 2011 and June 2014 were reviewed retrospectively. The height and width of the barium column at 1, 2, and 5 min were measured by TBE. Half-life (T 1/2, min) and R 30 (percentage of remaining radioactivity 30 s after radioisotope ingestion) were measured by ETS. Both tests were performed before and after treatment, and the tests were carried out 1 and 2 days after procedures. And we analyzed the correlation between the parameters from the two tests. The parameters of TBE and ETS were improved after treatment (p treatment, the height and width results at 5 min from TBE positively correlated with the T 1/2 parameter from ETS (correlation coefficients of 0.59 and 0.75, respectively). After treatment, the correlation coefficients between the 5-min height and width of the barium column by TBE and T 1/2 by ETS were 0.55 and 0.46, respectively. Both TBE and ETS are useful modalities in assessing esophageal emptying and response to achalasia treatment. TBE and ETS results have a statistically significant correlation both pre- and post-treatment. We suggest that TBE could effectively replace ETS for the assessment of achalasia.

  2. Measurement of oro-caecal transit time by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Savarino, Edoardo; De Cassan, Chiara [Division of Gastroenterology, Department of Surgical, Oncological and Gastroenterological Sciences, Padua (Italy); Savarino, Vincenzo; Furnari, Manuele; Marabotto, Elisa; Gemignani, Lorenzo; Bruzzone, Luca; Moscatelli, Alessandro [University of Genoa, Division of Gastroenterology, Department of Internal Medicine, Genoa (Italy); Fox, Mark [Queen' s Medical Center, NIHR Biomedical Research Unit, Nottingham Digestive Diseases Centre, Nottingham (United Kingdom); Di Leo, Giovanni [IRCCS Policlinico San Donato, Servizio di Radiologia, San Donato Milanese (Italy); Sardanelli, Francesco; Sconfienza, Luca Maria [IRCCS Policlinico San Donato, Servizio di Radiologia, San Donato Milanese (Italy); Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, San Donato Milanese, Milano (Italy)

    2015-06-01

    To assess prospectively the agreement of orocaecal transit time (OCTT) measurements by lactulose hydrogen breath test (LHBT) and magnetic resonance imaging (MRI) in healthy subjects. Volunteers underwent abdominal 1.5-T MRI using axial and coronal single-shot fast-spin-echo T2-weighted sequences, having fasted and after lactulose ingestion (10 g/125 mL). Imaging and H{sub 2} excretion gas-chromatography were performed concurrently every 15 min up to 180 min. MR images were analyzed using semiautomatic segmentation to calculate small bowel gas volume (SBGV) and visually to detect bolus arrival in the caecum. Agreement between MRI- and LHBT-OCTT was assessed. Twenty-eight subjects (17 men/11 women; mean age ± standard deviation 30 ± 8 years) were evaluated. Two H{sub 2} non-producers on LHBT were excluded. OCTT measured by MRI and LHBT was concordant in 18/26 (69 %) subjects (excellent agreement, k = 0.924). Median SBGV was 49.0 mL (interquartile interval 44.1 - 51.6 mL). In 8/26 (31 %) subjects, MRI showed that the lactulose bolus was in the terminal ileum and not the caecum when H{sub 2}E increased on LHBT. Median OCTT measured by MRI was significantly longer than OCTT measured by LHBT [135 min (120 - 150 min) vs. 127.5 min (105 - 150 min); p = 0.008]. Above baseline levels, correlation between [H{sub 2}] and SBGV was significant (r = 0.964; p < 0.001). MRI provides valid measurements of OCTT and gas production in the small bowel. (orig.)

  3. Usefulness of colon transit time and defecography in patients with chronic constipation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyoung Seuk; Chung, Jae Joon; Kim, Myung Hyun; Park, Su Mi; Yang, Hee Chul [NHIC Ilsan Hospital, Ilsan (Korea, Republic of)

    2006-05-15

    We wanted to evaluate whether both the colonic transit time (CTT) and defecography are necessary for diagnosing constipated patients, and we also wanted to assess the defecographic findings of patients with outlet obstruction on CTT. Over the recent 3 years, 26 patients (21 women and 5 men, mean age: 59 years) underwent both CTT and defecography because of their chronic constipations or defecation difficulty. The mean interval between the 2 studies was 48 days. Colonoscopy, barium enema and manometry were performed in 22, 8 and all the patients, respectively. On CTT, 13 patients (50.0%) were normal and 13 patients (50.0%) were abnormal; the abnormal results were composed of outlet obstruction (n = 8, 30.8%), outlet obstruction and colon inertia (n = 2, 7.7%), colon inertia (n = 2, 7.7%), and outlet obstruction and hindgut dysfunction (n = 1, 3.8%). On defecography, 6 patients (23.1%) were normal and 20 patients (76.9%) were abnormal; the results were composed of rectocele (n = 8, 30.7%), rectocele and perineal descent syndrome (PDS; n = 4, 15.4%), PDS and rectal intussusception (n = 3, 11.5%), spastic pelvic floor syndrome (SPFS; n = 3, 11.5%), rectocele and SPFS (n = 1, 3.8%), and rectal intussusception (n = 1, 3.8%). Of the 11 patients with outlet obstruction on CTT, rectocele (n = 4, 36.4%), SPFS (n = 1, 9.1%), rectocele and PDS (n = 1, 9.1%), and PDS and rectal intussusception (n = 1, 9.1%) were demonstrated on defecography, except for the 4 normal cases. Both CTT and defecography were necessary for diagnosing the patients with chronic constipation in compensation, and 63.6% of the patients with pelvic outlet obstruction showed an abnormal pelvic defecation function.

  4. Pulsatility index variations using two different transit-time flowmeters in coronary artery bypass surgery.

    Science.gov (United States)

    Nordgaard, Håvard B; Vitale, Nicola; Astudillo, Rafael; Renzulli, Attilio; Romundstad, Pål; Haaverstad, Rune

    2010-05-01

    Transit-time flow measurement is widely accepted as an intra-operative assessment in coronary artery bypass grafting (CABG). However, the two most commonly applied flowmeters, manufactured by MediStim ASA and Transonic Inc., have different default filter settings of 20 and 10 Hz, respectively. This may cause different flow measurements, which will influence the reported results. The aim was to compare pulsatility index (PI) values recorded by the MediStim and Transonic flowmeters in two different clinical settings: (1) analysis of the flow patterns recorded simultaneously by both flowmeters in the same CABGs; and (2) evaluation of flow patterns under different levels of filter settings in the same grafts. Graft flow and PI were measured using the two different flowmeters simultaneously in 19 bypass grafts. Finally, eight grafts were assessed under different digital filter settings at 5, 10, 20, 30, 50 and 100 Hz. The Transonic flowmeter provided substantially lower PI as compared with the MediStim flowmeter. By increasing the filter setting in the flowmeter, PI increased considerably. The Transonic flowmeter displayed a lower PI than the MediStim, due to a lower filter setting. In the Transonic,flow signals are filtered at a lower level, rendering a 'smoother' pattern of flow curves. Because different filter settings determine different PIs, caution must be taken when flow values and flowmeters are compared. The type of flowmeter should be indicated whenever graft flow measurements and derived indexes are provided [corrected]. Copyright 2009 European Association for Cardio-Thoracic Surgery. All rights reserved.

  5. Female labor market transitions and the timing of births: a simultaneous analysis of the effects of schooling

    NARCIS (Netherlands)

    Bloemen, H.G.; Kalwij, A.S.

    2001-01-01

    This paper develops a simultaneous analysis of the timing of births and labor market transitions of women in the Netherlands. The results show that an increase in the years of schooling of a woman causes her to schedule births later in life but it does not significantly affect her completed

  6. Points of Transition: Understanding the Constructed Identities of L2 Learners/Users across Time and Space

    Science.gov (United States)

    Adawu, Anthony; Martin-Beltran, Melinda

    2012-01-01

    Using sociocultural and poststructuralist theoretical lenses, this study examines the narrative construction of language-learner identity across time and space. We applied cross-narrative methodologies to analyze language-learning autobiographies and interview data from three English users who had recently transitioned to a U.S. context for…

  7. Influence of a subsequent meal on the oro-cecal transit time of a solid test meal

    NARCIS (Netherlands)

    Priebe, MG; Wachters-Hagedoorn, RE; Landman, K; Heimweg, J; Elzinga, H; Vonk, RJ

    Oro-cecal transit time (OCTT) is determined for clinical diagnostics of intestinal complaints and research purposes. Ingestion of a subsequent meal during the test period shortens the OCTT of a liquid test meal (glucose solution), as previously reported. This study was conducted to determine whether

  8. Dating of streamwater using tritium in a post nuclear bomb pulse world: continuous variation of mean transit time with streamflow

    Directory of Open Access Journals (Sweden)

    U. Morgenstern

    2010-11-01

    Full Text Available Tritium measurements of streamwater draining the Toenepi catchment, a small dairy farming area in Waikato, New Zealand, have shown that the mean transit time of the water varies with the flow rate of the stream. Mean transit times through the catchment are 2–5 years during high baseflow conditions in winter, increasing to 30–40 years as baseflow decreases in summer, and then dramatically older water during drought conditions with mean transit time of more than 100 years. Older water is gained in the lower reaches of the stream, compared to younger water in the headwater catchment. The groundwater store supplying baseflow was estimated from the mean transit time and average baseflow to be 15.4 × 106 m3 of water, about 1 m water equivalent over the catchment and 2.3 times total annual streamflow. Nitrate is relatively high at higher flow rates in winter, but is low at times of low flow with old water. This reflects both lower nitrate loading in the catchment several decades ago as compared to current intensive dairy farming, and denitrification processes occurring in the older groundwater. Silica, leached from the aquifer material and accumulating in the water in proportion to contact time, is high at times of low streamflow with old water. There was a good correlation between silica concentration and streamwater age, which potentially allows silica concentrations to be used as a proxy for age when calibrated by tritium measurements. This study shows that tritium dating of stream water is possible with single tritium measurements now that bomb-test tritium has effectively disappeared from hydrological systems in New Zealand, without the need for time-series data.

  9. A Capacity-Restraint Transit Assignment Model When a Predetermination Method Indicates the Invalidity of Time Independence

    Directory of Open Access Journals (Sweden)

    Haoyang Ding

    2015-01-01

    Full Text Available The statistical independence of time of every two adjacent bus links plays a crucial role in deciding the feasibility of using many mathematical models to analyze urban transit networks. Traditional research generally ignores the time independence that acts as the ground of their models. Assumption is usually made that time independence of every two adjacent links is sound. This is, however, actually groundless and probably causes problematic conclusions reached by corresponding models. Many transit assignment models such as multinomial probit-based models lose their effects when the time independence is not valid. In this paper, a simple method to predetermine the time independence is proposed. Based on the predetermination method, a modified capacity-restraint transit assignment method aimed at engineering practice is put forward and tested through a small contrived network and a case study in Nanjing city, China, respectively. It is found that the slope of regression equation between the mean and standard deviation of normal distribution acts as the indicator of time independence at the same time. Besides, our modified assignment method performs better than the traditional one with more reasonable results while keeping the property of simplicity well.

  10. Nonlinearities and transit times in soil organic matter models: new developments in the SoilR package

    Science.gov (United States)

    Sierra, Carlos; Müller, Markus

    2016-04-01

    SoilR is an R package for implementing diverse models representing soil organic matter dynamics. In previous releases of this package, we presented the implementation of linear first-order models with any number of pools as well as radiocarbon dynamics. We present here new improvements of the package regarding the possibility to implement models with nonlinear interactions among state variables and the possibility to calculate ages and transit times for nonlinear models with time dependencies. We show here examples on how to implement model structures with Michaelis-Menten terms for explicit microbial growth and resource use efficiency, and Langmuir isotherms for representing adsorption of organic matter to mineral surfaces. These nonlinear terms can be implemented for any number of organic matter pools, microbial functional groups, or mineralogy, depending on user's requirements. Through a simple example, we also show how transit times of organic matter in soils are controlled by the time-dependencies of the input terms.

  11. THE KEPLER-19 SYSTEM: A TRANSITING 2.2 R{sub Circled-Plus} PLANET AND A SECOND PLANET DETECTED VIA TRANSIT TIMING VARIATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Ballard, Sarah; Fressin, Francois; Charbonneau, David; Desert, Jean-Michel; Torres, Guillermo; Holman, Matthew J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fabrycky, Daniel [Department of Astronomy and Astrophysics, University of California Santa Cruz, Santa Cruz, CA 95064 (United States); Marcy, Geoffrey; Isaacson, Howard [Department of Astronomy, University of California Berkeley, Berkeley, CA 94720 (United States); Burke, Christopher J.; Henze, Christopher; Howell, Steven B.; Bryson, Stephen T.; Rowe, Jason F.; Lissauer, Jack J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, Batavia, IL 60510 (United States); Ciardi, David R. [NASA Exoplanet Science Institute/Caltech, Pasadena, CA 91125 (United States); Cochran, William D.; Endl, Michael [McDonald Observatory, The University of Texas, Austin, TX 78712 (United States); Jenkins, Jon M., E-mail: sballard@cfa.harvard.edu [SETI Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); and others

    2011-12-20

    We present the discovery of the Kepler-19 planetary system, which we first identified from a 9.3 day periodic transit signal in the Kepler photometry. From high-resolution spectroscopy of the star, we find a stellar effective temperature T{sub eff} = 5541 {+-} 60 K, a metallicity [Fe/H] = -0.13 {+-} 0.06, and a surface gravity log(g) = 4.59 {+-} 0.10. We combine the estimate of T{sub eff} and [Fe/H] with an estimate of the stellar density derived from the photometric light curve to deduce a stellar mass of M{sub *} = 0.936 {+-} 0.040 M{sub Sun} and a stellar radius of R{sub *} = 0.850 {+-} 0.018 R{sub Sun} (these errors do not include uncertainties in the stellar models). We rule out the possibility that the transits result from an astrophysical false positive by first identifying the subset of stellar blends that reproduce the precise shape of the light curve. Using the additional constraints from the measured color of the system, the absence of a secondary source in the high-resolution spectrum, and the absence of a secondary source in the adaptive optics imaging, we conclude that the planetary scenario is more than three orders of magnitude more likely than a blend. The blend scenario is independently disfavored by the achromaticity of the transit: we measure a transit depth with Spitzer at 4.5 {mu}m of 547{sup +113}{sub -110} ppm, consistent with the depth measured in the Kepler optical bandpass of 567 {+-} 6 ppm (corrected for stellar limb darkening). We determine a physical radius of the planet Kepler-19b of R{sub p} = 2.209 {+-} 0.048 R{sub Circled-Plus }; the uncertainty is dominated by uncertainty in the stellar parameters. From radial velocity observations of the star, we find an upper limit on the planet mass of 20.3 M{sub Circled-Plus }, corresponding to a maximum density of 10.4 g cm{sup -3}. We report a significant sinusoidal deviation of the transit times from a predicted linear ephemeris, which we conclude is due to an additional perturbing body in

  12. CHARACTERIZATION OF THE K2-19 MULTIPLE-TRANSITING PLANETARY SYSTEM VIA HIGH-DISPERSION SPECTROSCOPY, AO IMAGING, AND TRANSIT TIMING VARIATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Narita, Norio; Hori, Yasunori; Kusakabe, Nobuhiko; Takeda, Yoichi; Tamura, Motohide [Astrobiology Center, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588 (Japan); Hirano, Teruyuki [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Fukui, Akihiko; Yanagisawa, Kenshi [Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Asakuchi, Okayama 719-0232 (Japan); Sanchis-Ojeda, Roberto [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Winn, Joshua N. [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Ryu, Tsuguru; Onitsuka, Masahiro [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588 (Japan); Kudo, Tomoyuki [Subaru Telescope, 650 North A’ohoku Place, Hilo, HI 96720 (United States); Delrez, Laetitia; Gillon, Michael; Jehin, Emmanuel [Institut d’Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août 17, Bat. B5C, B-4000 Liège (Belgium); McCormac, James [Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL (United Kingdom); Holman, Matthew [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Izumiura, Hideyuki, E-mail: norio.narita@nao.ac.jp [SOKENDAI (The Graduate University for Advanced Studies), 2-21-1 Osawa, Mitaka, Tokyo, 181-8588 (Japan)

    2015-12-10

    K2-19 (EPIC201505350) is an interesting planetary system in which two transiting planets with radii ∼7 R{sub ⊕} (inner planet b) and ∼4 R{sub ⊕} (outer planet c) have orbits that are nearly in a 3:2 mean-motion resonance. Here, we present results of ground-based follow-up observations for the K2-19 planetary system. We have performed high-dispersion spectroscopy and high-contrast adaptive-optics imaging of the host star with the HDS and HiCIAO on the Subaru 8.2 m telescope. We find that the host star is a relatively old (≥8 Gyr) late G-type star (T{sub eff} ∼ 5350 K, M{sub s} ∼ 0.9 M{sub ⊙}, and R{sub s} ∼ 0.9 R{sub ⊙}). We do not find any contaminating faint objects near the host star that could be responsible for (or dilute) the transit signals. We have also conducted transit follow-up photometry for the inner planet with KeplerCam on the FLWO 1.2 m telescope, TRAPPISTCAM on the TRAPPIST 0.6 m telescope, and MuSCAT on the OAO 1.88 m telescope. We confirm the presence of transit timing variations (TTVs), as previously reported by Armstrong and coworkers. We model the observed TTVs of the inner planet using the synodic chopping formulae given by Deck and Agol. We find two statistically indistinguishable solutions for which the period ratios (P{sub c}/P{sub b}) are located slightly above and below the exact 3:2 commensurability. Despite the degeneracy, we derive the orbital period of the inner planet P{sub b} ∼ 7.921 days and the mass of the outer planet M{sub c} ∼ 20 M{sub ⊕}. Additional transit photometry (especially for the outer planet) as well as precise radial-velocity measurements would be helpful to break the degeneracy and to determine the mass of the inner planet.

  13. Laboratory medicine handoff gaps experienced by primary care practices: A report from the shared networks of collaborative ambulatory practices and partners (SNOCAP).

    Science.gov (United States)

    West, David R; James, Katherine A; Fernald, Douglas H; Zelie, Claire; Smith, Maxwell L; Raab, Stephen S

    2014-01-01

    The majority of errors in laboratory medicine testing are thought to occur in the pre- and postanalytic testing phases, and a large proportion of these errors are secondary to failed handoffs. Because most laboratory tests originate in ambulatory primary care, understanding the gaps in handoff processes within and between laboratories and practices is imperative for patient safety. Therefore, the purpose of this study was to understand, based on information from primary care practice personnel, the perceived gaps in laboratory processes as a precursor to initiating process improvement activities. A survey was used to assess perceptions of clinicians, staff, and management personnel of gaps in handoffs between primary care practices and laboratories working in 21 Colorado primary care practices. Data were analyzed to determine statistically significant associations between categorical variables. In addition, qualitative analysis of responses to open-ended survey questions was conducted. Primary care practices consistently reported challenges and a desire/need to improve their efforts to systematically track laboratory test status, confirm receipt of laboratory results, and report results to patients. Automated tracking systems existed in roughly 61% of practices, and all but one of those had electronic health record-based tracking systems in place. One fourth of these electronic health record-enabled practices expressed sufficient mistrust in these systems to warrant the concurrent operation of an article-based tracking system as backup. Practices also reported 12 different procedures used to notify patients of test results, varying by test result type. The results highlight the lack of standardization and definition of roles in handoffs in primary care laboratory practices for test ordering, monitoring, and receiving and reporting test results. Results also identify high-priority gaps in processes and the perceptions by practice personnel that practice improvement

  14. Analyses of kinetic glass transition in short-range attractive colloids based on time-convolutionless mode-coupling theory.

    Science.gov (United States)

    Narumi, Takayuki; Tokuyama, Michio

    2017-03-01

    For short-range attractive colloids, the phase diagram of the kinetic glass transition is studied by time-convolutionless mode-coupling theory (TMCT). Using numerical calculations, TMCT is shown to recover all the remarkable features predicted by the mode-coupling theory for attractive colloids: the glass-liquid-glass reentrant, the glass-glass transition, and the higher-order singularities. It is also demonstrated through the comparisons with the results of molecular dynamics for the binary attractive colloids that TMCT improves the critical values of the volume fraction. In addition, a schematic model of three control parameters is investigated analytically. It is thus confirmed that TMCT can describe the glass-glass transition and higher-order singularities even in such a schematic model.

  15. Transition times between the extremum points of the current–voltage characteristic of a resonant tunneling diode with hysteresis

    Energy Technology Data Exchange (ETDEWEB)

    Grishakov, K. S., E-mail: ksgrishakov@yahoo.com; Elesin, V. F. [National Research Nuclear University “MEPhI” (Russian Federation)

    2016-08-15

    A numerical solution to the problem of transient processes in a resonant tunneling diode featuring a current–voltage characteristic with hysteresis is found for the first time in the context of a coherent model (based on the coupled Schrödinger and Poisson equations) taking into account the Fermi distribution of electrons. The transitions from the high-current to the low-current state and vice versa, which result from the existence of hysteresis and are of great practical importance for ultrafast switches based on resonant tunneling diodes, are studied in detail. It is shown that the transition times for such processes initiated by the application of a small voltage can significantly exceed the characteristic time ℏ/Γ (where G is the width of the resonance level). It is established for the first time that the transition time can be reduced and made as short as the characteristic time ℏ/Γ by applying a sufficiently high voltage. For the parameters of the resonant-tunnelingdiode structure considered in this study, the required voltage is about 0.01 V.

  16. Mean transit times in headwater catchments: insights from the Otway Ranges, Australia

    Directory of Open Access Journals (Sweden)

    W. Howcroft

    2018-01-01

    Full Text Available Understanding the timescales of water flow through catchments and the sources of stream water at different flow conditions is critical for understanding catchment behaviour and managing water resources. Here, tritium (3H activities, major ion geochemistry and streamflow data were used in conjunction with lumped parameter models (LPMs to investigate mean transit times (MTTs and the stores of water in six headwater catchments in the Otway Ranges of southeastern Australia. 3H activities of stream water ranged from 0.20 to 2.14 TU, which are significantly lower than the annual average 3H activity of modern local rainfall, which is between 2.4 and 3.2 TU. The 3H activities of the stream water are lowest during low summer flows and increase with increasing streamflow. The concentrations of most major ions vary little with streamflow, which together with the low 3H activities imply that there is no significant direct input of recent rainfall at the streamflows sampled in this study. Instead, shallow younger water stores in the soils and regolith are most likely mobilised during the wetter months. MTTs vary from approximately 7 to 230 years. Despite uncertainties of several years in the MTTs that arise from having to assume an appropriate LPM, macroscopic mixing, and uncertainties in the 3H activities of rainfall, the conclusion that they range from years to decades is robust. Additionally, the relative differences in MTTs at different streamflows in the same catchment are estimated with more certainty. The MTTs in these and similar headwater catchments in southeastern Australia are longer than in many catchments globally. These differences may reflect the relatively low rainfall and high evapotranspiration rates in southeastern Australia compared with headwater catchments elsewhere. The long MTTs imply that there is a long-lived store of water in these catchments that can sustain the streams over drought periods lasting several years. However, the

  17. Mean transit times in headwater catchments: insights from the Otway Ranges, Australia

    Science.gov (United States)

    Howcroft, William; Cartwright, Ian; Morgenstern, Uwe

    2018-01-01

    Understanding the timescales of water flow through catchments and the sources of stream water at different flow conditions is critical for understanding catchment behaviour and managing water resources. Here, tritium (3H) activities, major ion geochemistry and streamflow data were used in conjunction with lumped parameter models (LPMs) to investigate mean transit times (MTTs) and the stores of water in six headwater catchments in the Otway Ranges of southeastern Australia. 3H activities of stream water ranged from 0.20 to 2.14 TU, which are significantly lower than the annual average 3H activity of modern local rainfall, which is between 2.4 and 3.2 TU. The 3H activities of the stream water are lowest during low summer flows and increase with increasing streamflow. The concentrations of most major ions vary little with streamflow, which together with the low 3H activities imply that there is no significant direct input of recent rainfall at the streamflows sampled in this study. Instead, shallow younger water stores in the soils and regolith are most likely mobilised during the wetter months. MTTs vary from approximately 7 to 230 years. Despite uncertainties of several years in the MTTs that arise from having to assume an appropriate LPM, macroscopic mixing, and uncertainties in the 3H activities of rainfall, the conclusion that they range from years to decades is robust. Additionally, the relative differences in MTTs at different streamflows in the same catchment are estimated with more certainty. The MTTs in these and similar headwater catchments in southeastern Australia are longer than in many catchments globally. These differences may reflect the relatively low rainfall and high evapotranspiration rates in southeastern Australia compared with headwater catchments elsewhere. The long MTTs imply that there is a long-lived store of water in these catchments that can sustain the streams over drought periods lasting several years. However, the catchments are likely

  18. Long Spin-Relaxation Times in a Transition-Metal Atom in Direct Contact to a Metal Substrate.

    Science.gov (United States)

    Hermenau, Jan; Ternes, Markus; Steinbrecher, Manuel; Wiesendanger, Roland; Wiebe, Jens

    2018-03-14

    Long spin-relaxation times are a prerequisite for the use of spins in data storage or nanospintronics technologies. An atomic-scale solid-state realization of such a system is the spin of a transition-metal atom adsorbed on a suitable substrate. For the case of a metallic substrate, which enables the direct addressing of the spin by conduction electrons, the experimentally measured lifetimes reported to date are on the order of only hundreds of femtoseconds. Here, we show that the spin states of iron atoms adsorbed directly on a conductive platinum substrate have a surprisingly long spin-relaxation time in the nanosecond regime, which is comparable to that of a transition metal atom decoupled from the substrate electrons by a thin decoupling layer. The combination of long spin-relaxation times and strong coupling to conduction electrons implies the possibility to use flexible coupling schemes to process the spin information.

  19. A maximum entropy method to compute the 13NH3 pulmonary transit time from right to left ventricle in cardiac PET studies

    DEFF Research Database (Denmark)

    Steenstrup, Stig; Hove, Jens D; Kofoed, Klaus

    2002-01-01

    The distribution function of pulmonary transit times (fPTTs) contains information on the transit time of blood through the lungs and the dispersion in transit times. Most of the previous studies have used specific functional forms with adjustable parameters to characterize the fPTT. It is the pur......, we were able to accurately identify a two-peaked transfer function, which may theoretically be seen in patients with pulmonary disease confined to one lung. Transit time values for [13N]-ammonia were produced by applying the algorithm to PET studies from normal volunteers....

  20. 77 FR 77180 - Notice of Transportation Services' OMB Designation, timely return of excess transit benefits to...

    Science.gov (United States)

    2012-12-31

    ... lead Federal agency to inform commercial vanpool companies of the Federal internal controls that govern... the Treasury, and stakeholder notification of the minimum internal controls AGENCY: Office of the... internal controls that now govern the Transit Benefit Program to prevent future accumulations, and assist...

  1. Carrying the Beacon of Excellence: Social Class Differentiation and Anxiety at a Time of Transition.

    Science.gov (United States)

    Lucey, Helen; Reay, Diane

    2002-01-01

    Examines ways in which current United Kingdom school-choice policies interact with parental pressures on their children to achieve excellence and how these pressures affect the emotional health of their middle- and working-class children as they make the transition from primary to secondary school. Finds serious emotional consequences (exam…

  2. Study of the ferroelectric phase transition in germanium telluride using time-domain terahertz spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Kadlec, Filip; Kadlec, Christelle; Kužel, Petr; Petzelt, Jan

    2011-01-01

    Roč. 84, č. 20 (2011), 205209/1-205209/8 ISSN 1098-0121 R&D Projects: GA ČR GC202/09/J045 Institutional research plan: CEZ:AV0Z10100520 Keywords : terahertz spectroscopy * phase transition * semiconductor Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.691, year: 2011

  3. Timing, cause and consequences of mid-Holocene climate transition in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswat, R.; Naik, Dinesh K.; Nigam, R.; Gaur, A.S.

    -50,000 years cal BP. Radiocarbon 51, 1111-1150. Roberts, N., Brayshaw, D., Kuzucuoglu, C., Perez, R., Sadori, L., 2011. The mid-Holocene climatic transition in the Mediterranean: Causes and consequences. The Holocene 21, 3-13. Ruddiman, W.F., Ellis, E...

  4. A Transition-to-College Course for Adult Learners: Effects on GPA and Time to Graduation

    Science.gov (United States)

    Collins, Pamela J.

    2013-01-01

    The purpose of this study was to help fill the knowledge gap on stand-alone transition-to-college courses for adult students in an institutional setting where such courses have been extensively utilized via different delivery mediums. The ultimate goal was to use the knowledge obtained to aid personnel who work with nontraditional degree programs…

  5. On the use of spring baseflow recession for a more accurate parameterization of aquifer transit time distribution functions

    Directory of Open Access Journals (Sweden)

    J. Farlin

    2013-05-01

    Full Text Available Baseflow recession analysis and groundwater dating have up to now developed as two distinct branches of hydrogeology and have been used to solve entirely different problems. We show that by combining two classical models, namely the Boussinesq equation describing spring baseflow recession, and the exponential piston-flow model used in groundwater dating studies, the parameters describing the transit time distribution of an aquifer can be in some cases estimated to a far more accurate degree than with the latter alone. Under the assumption that the aquifer basis is sub-horizontal, the mean transit time of water in the saturated zone can be estimated from spring baseflow recession. This provides an independent estimate of groundwater transit time that can refine those obtained from tritium measurements. The approach is illustrated in a case study predicting atrazine concentration trend in a series of springs draining the fractured-rock aquifer known as the Luxembourg Sandstone. A transport model calibrated on tritium measurements alone predicted different times to trend reversal following the nationwide ban on atrazine in 2005 with different rates of decrease. For some of the springs, the actual time of trend reversal and the rate of change agreed extremely well with the model calibrated using both tritium measurements and the recession of spring discharge during the dry season. The agreement between predicted and observed values was however poorer for the springs displaying the most gentle recessions, possibly indicating a stronger influence of continuous groundwater recharge during the summer months.

  6. Improving the transition of care in patients transferred through the ochsner medical center transfer center.

    Science.gov (United States)

    Amedee, Ronald G; Maronge, Genevieve F; Pinsky, William W

    2012-01-01

    Patient transfers from other hospitals within the Ochsner Health System to the main campus are coordinated through a Transfer Center that was established in fall 2008. We analyzed the transfer process to assess distinct opportunities to enhance the overall transition of patient care. We surveyed internal medicine residents and nocturnists to determine their satisfaction with transfers in terms of safety, efficiency, and usefulness of information provided at the time of transfer. After a kaizen event at which complementary goals for the institution and members of the study team were recognized and implemented, we resurveyed the group to evaluate improvement in the transfer process. The preintervention average satisfaction score was 1.18 (SD=0.46), while the postintervention score was 3.7 (SD=1.01). A t test showed a significant difference in the average scores between the preintervention and postintervention surveys (Pkaizen event), data were collected that facilitated fewer and higher quality handoffs that were performed in less time. In addition, the process resulted in increased awareness of the value of resident participation in institutional quality improvement projects.

  7. Domperidone prolongs oral to duodenal transit time in video capsule endoscopy.

    Science.gov (United States)

    Mcfarlane, Michael; Liu, B; Nwokolo, C

    2018-04-01

    Domperidone is thought to accelerate gastric emptying via D2 receptor antagonism at the gastro-oesophageal and gastro-duodenal junctions. Listed in the BNF as a prokinetic anti-emetic, it has been used in video capsule endoscopy (VCE) to accelerate capsule delivery to the small intestine. We audited VCEs performed at UHCW from 2011, when as standard practice, domperidone was given pre-VCE, to 2012, after its discontinuation due to doubts about its effectiveness. Thirty-one patients received oral domperidone 20 mg pre-VCE. Thirty-three patients underwent VCE without domperidone pre-treatment. After 2 h, if the capsule remained intra-gastric, gastroscopy-assisted duodenal delivery was performed. Data was analysed using Mann-Whitney testing. Median oro-duodenal transit was 13 and 30 min in the untreated and domperidone groups, respectively (p = 0.01). Median oro-caecal transit was 242 and 267 min in the untreated and domperidone groups, respectively (p = 0.02). No difference in duodenal-caecal transit was seen (p = 0.60). Six percent of untreated and 13% of domperidone VCEs required gastroscopy-assisted duodenal capsule delivery (p = 0.65). Unexpectedly domperidone delayed VCE gastric transit. Most studies on domperidone prokinetic effects have been in diabetic gastroparesis, demonstrating that domperidone can achieve good symptomatic relief, but with mixed results for gastric emptying. Our study suggests that any antiemetic effects of domperidone are not mediated through accelerated gastric transit.

  8. TRANSIT TIMING OBSERVATIONS FROM KEPLER. IV. CONFIRMATION OF FOUR MULTIPLE-PLANET SYSTEMS BY SIMPLE PHYSICAL MODELS

    International Nuclear Information System (INIS)

    Fabrycky, Daniel C.; Ford, Eric B.; Moorhead, Althea V.; Steffen, Jason H.; Rowe, Jason F.; Christiansen, Jessie L.; Carter, Joshua A.; Fressin, Francois; Geary, John; Batalha, Natalie M.; Borucki, William J.; Bryson, Steve; Haas, Michael R.; Buchhave, Lars A.; Ciardi, David R.; Cochran, William D.; Endl, Michael; Fanelli, Michael N.; Fischer, Debra; Hall, Jennifer R.

    2012-01-01

    Eighty planetary systems of two or more planets are known to orbit stars other than the Sun. For most, the data can be sufficiently explained by non-interacting Keplerian orbits, so the dynamical interactions of these systems have not been observed. Here we present four sets of light curves from the Kepler spacecraft, each which of shows multiple planets transiting the same star. Departure of the timing of these transits from strict periodicity indicates that the planets are perturbing each other: the observed timing variations match the forcing frequency of the other planet. This confirms that these objects are in the same system. Next we limit their masses to the planetary regime by requiring the system remain stable for astronomical timescales. Finally, we report dynamical fits to the transit times, yielding possible values for the planets' masses and eccentricities. As the timespan of timing data increases, dynamical fits may allow detailed constraints on the systems' architectures, even in cases for which high-precision Doppler follow-up is impractical.

  9. TRANSIT TIMING OBSERVATIONS FROM KEPLER. IV. CONFIRMATION OF FOUR MULTIPLE-PLANET SYSTEMS BY SIMPLE PHYSICAL MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, Santa Cruz, CA 95064 (United States); Ford, Eric B.; Moorhead, Althea V. [Astronomy Department, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL 32111 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Rowe, Jason F.; Christiansen, Jessie L. [SETI Institute, Mountain View, CA 94043 (United States); Carter, Joshua A.; Fressin, Francois; Geary, John [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Borucki, William J.; Bryson, Steve; Haas, Michael R. [NASA Ames Research Center, Moffett Field, CA, 94035 (United States); Buchhave, Lars A. [Department of Astrophysics and Planetary Science, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Ciardi, David R. [NASA Exoplanet Science Institute/Caltech, Pasadena, CA 91126 (United States); Cochran, William D.; Endl, Michael [McDonald Observatory, The University of Texas, Austin TX 78730 (United States); Fanelli, Michael N. [Bay Area Environmental Research Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Fischer, Debra [Astronomy Department, Yale University, New Haven, CT (United States); Hall, Jennifer R., E-mail: daniel.fabrycky@gmail.com [Orbital Sciences Corporation/NASA Ames Research Center, Moffett Field, CA 94035 (United States); and others

    2012-05-10

    Eighty planetary systems of two or more planets are known to orbit stars other than the Sun. For most, the data can be sufficiently explained by non-interacting Keplerian orbits, so the dynamical interactions of these systems have not been observed. Here we present four sets of light curves from the Kepler spacecraft, each which of shows multiple planets transiting the same star. Departure of the timing of these transits from strict periodicity indicates that the planets are perturbing each other: the observed timing variations match the forcing frequency of the other planet. This confirms that these objects are in the same system. Next we limit their masses to the planetary regime by requiring the system remain stable for astronomical timescales. Finally, we report dynamical fits to the transit times, yielding possible values for the planets' masses and eccentricities. As the timespan of timing data increases, dynamical fits may allow detailed constraints on the systems' architectures, even in cases for which high-precision Doppler follow-up is impractical.

  10. How does subsurface retain and release stored water? An explicit estimation of young water fraction and mean transit time

    Science.gov (United States)

    Ameli, Ali; McDonnell, Jeffrey; Laudon, Hjalmar; Bishop, Kevin

    2017-04-01

    The stable isotopes of water have served science well as hydrological tracers which have demonstrated that there is often a large component of "old" water in stream runoff. It has been more problematic to define the full transit time distribution of that stream water. Non-linear mixing of previous precipitation signals that is stored for extended periods and slowly travel through the subsurface before reaching the stream results in a large range of possible transit times. It difficult to find tracers can represent this, especially if all that one has is data on the precipitation input and the stream runoff. In this paper, we explicitly characterize this "old water" displacement using a novel quasi-steady physically-based flow and transport model in the well-studied S-Transect hillslope in Sweden where the concentration of hydrological tracers in the subsurface and stream has been measured. We explore how subsurface conductivity profile impacts the characteristics of old water displacement, and then test these scenarios against the observed dynamics of conservative hydrological tracers in both the stream and subsurface. This work explores the efficiency of convolution-based approaches in the estimation of stream "young water" fraction and time-variant mean transit times. We also suggest how celerity and velocity differ with landscape structure

  11. Cooperative effect of random and time-periodic coupling strength on synchronization transitions in one-way coupled neural system: mean field approach.

    Science.gov (United States)

    Jiancheng, Shi; Min, Luo; Chusheng, Huang

    2017-08-01

    The cooperative effect of random coupling strength and time-periodic coupling strengh on synchronization transitions in one-way coupled neural system has been investigated by mean field approach. Results show that cooperative coupling strength (CCS) plays an active role for the enhancement of synchronization transitions. There exist an optimal frequency of CCS which makes the system display the best CCS-induced synchronization transitions, a critical frequency of CCS which can not further affect the CCS-induced synchronization transitions, and a critical amplitude of CCS which can not occur the CCS-induced synchronization transitions. Meanwhile, noise intensity plays a negative role for the CCS-induced synchronization transitions. Furthermore, it is found that the novel CCS amplitude-induced synchronization transitions and CCS frequency-induced synchronization transitions are found.

  12. A Numerical Scheme for Ordinary Differential Equations Having Time Varying and Nonlinear Coefficients Based on the State Transition Matrix

    Science.gov (United States)

    Bartels, Robert E.

    2002-01-01

    A variable order method of integrating initial value ordinary differential equations that is based on the state transition matrix has been developed. The method has been evaluated for linear time variant and nonlinear systems of equations. While it is more complex than most other methods, it produces exact solutions at arbitrary time step size when the time variation of the system can be modeled exactly by a polynomial. Solutions to several nonlinear problems exhibiting chaotic behavior have been computed. Accuracy of the method has been demonstrated by comparison with an exact solution and with solutions obtained by established methods.

  13. Polynomial-time Algorithms for Computing Distances of Fuzzy Transition Systems

    OpenAIRE

    Chen, Taolue; Han, Tingting; Cao, Yongzhi

    2017-01-01

    Behaviour distances to measure the resemblance of two states in a (nondeterministic) fuzzy transition system have been proposed recently in the literature. Such a distance, defined as a pseudo-ultrametric over the state space of the model, provides a quantitative analogue of bisimilarity. In this paper, we focus on the problem of computing these distances. We first extend the definition of the pseudo-ultrametric by introducing discount such that the discounting factor being equal to 1 capture...

  14. Overcoming energy injustice? Bulgaria’s renewable energy transition in times of crisis

    OpenAIRE

    Andreas, Jan-Justus; Burns, Charlotte Jennie; Touza-Montero, Julia Maria

    2018-01-01

    The effects of renewable energy transitions on energy costs and economic growth have led to cost concerns and a prioritisation of economic issues during the economic crisis. Bulgaria, the EU's poorest state has nevertheless already achieved its 2020 renewable energy targets. This achievement seems to challenge the widely held as- sumption that poorer countries struggle to meet environmental objectives. This paper analyses the drivers and implications of Bulgaria's renewables expansion in orde...

  15. Suppression of the asymmetric competition mode in the relativistic Ku-band coaxial transit-time oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Junpu; He, Juntao; Zhang, Jiande; Jiang, Tao; Wang, Lei [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2014-10-15

    A relativistic Ku-band coaxial transit-time oscillator has been proposed in our previous work. In the experiments, we find that the asymmetric competition mode in the device limits the microwave power with the increase of the input electric power. For solving such a problem, the methods for analysis and suppression of the asymmetric competition mode in the device are investigated theoretically and experimentally. It is shown that the structure and the material of the collector, the concentricity, and the electron emission uniformity play an important part in the suppression of the asymmetric competition mode in the relativistic Ku-band transit-time oscillator. In the subsequent experiments, the asymmetric mode was suppressed effectively. At a low guiding magnetic field of 0.7 T, a microwave pulse with power of 1 GW, frequency of 14.3 GHz close to the simulation one, and efficiency of 20% was generated.

  16. Usage of the micropixel detector TimePix for observation of the dynamics of phase transitions in metals

    Directory of Open Access Journals (Sweden)

    M. V. Pugach

    2012-12-01

    Full Text Available The results for the test of a TimePix hybrid detector as a tool for measuring and imaging in real time dynamics of phase transitions in metal alloys under heating or cooling are presented. The X-rays ( ~ 10 keV experimental setup explored for the diffraction studies at the Institute for Problems of Material Science NASU (Kyiv is briefly described. An evolution of the diffraction maxima position (~ 20 μm accuracy of the scattered X-rays was ob-served with exposures from a few dozen to a few hundred milliseconds under heating or cooling of the samples of Armco iron at a rate of 100 to 250 C/s. Data for the phase transitions (alpha-, gamma-phases observed during heating/cooling (20 - 1250 °C using the X-ray diffraction were measured.

  17. Transitions between child and adult mental health services: service design, philosophy and meaning at uncertain times.

    Science.gov (United States)

    Murcott, W J

    2014-09-01

    A young person's transition of care from child and adolescent mental health services to adult mental health services can be an uncertain and distressing event that can have serious ramifications for their recovery. Recognition of this across many countries and recent UK media interest in the dangers of mental health services failing young people has led practitioners to question the existing processes. This paper reviews the current theories and research into potential failings of services and encourages exploration for a deeper understanding of when and how care should be managed in the transition process for young people. Mental health nurses can play a vital role in this process and, by adopting the assumptions of this paradigm, look at transition from this unique perspective. By reviewing the current ideas related to age boundaries, service thresholds, service philosophy and service design, it is argued that the importance of the therapeutic relationship, the understanding of the cultural context of the young person and the placing of the young person in a position of autonomy and control should be central to any decision and process of transfer between two mental health services. © 2014 John Wiley & Sons Ltd.

  18. Transforming Education for a Transition into Human-centered Economy and Post-normal Times

    Directory of Open Access Journals (Sweden)

    Elif Çepni

    2017-10-01

    Full Text Available Solutions to the major problems of our time require a radical shift in our perceptions, thinking and values. Post-normal times (characterized by complexity, chaos and contradictions, post-normal science (characterized by uncertainties, systems view of thinking, alternative perspectives, unknown unknowns, values and human-centered economy are conceptions that we need to take into consideration to define a new role for science. Managing the transition from the knowledge economy (mainly dominated by the use of analytical skills to human-centered economy (mainly dominated by the use of creativity, character, passion requires visionary leadership and a wide range of partnerships, and developing new and more comprehensive, flexible, innovative models of learning. Education today should prepare current generations for the continuously changing world of the future. The critique on modern education ranges across the political spectrum (from ‘the Right’ to ‘the Left’; across countries (both ‘western’ and ‘non-western’; across genders (within men’s, queer and feminist movements; and across worldviews (e.g. post-modernism, critical theory, neo-Marxism, critical traditionalism. These critiques all imply that ‘modern’ education has now become ‘outdated’ (Milojevic, 2005. Technology and globalization are significantly transforming work. However, education and training systems, having remained mostly static and under-invested in for decades, are largely inadequate to meet the needs of the new labour markets. How the disconnect between education systems and labour markets can be eliminated is a much disputed topic and it may require a paradigm shift in current thinking. Citizens and consumers today are experiencing a growing sense of alienation, loss of values and flexibility (Zajda, 2009. There is no form of education which would meet different needs worldwide. Education is a basic human right and it cannot be purely demand

  19. A stochastic mathematical model for determination of transition time in the non-simultaneous case of surface and underground mining

    OpenAIRE

    Bakhtavar, E.; Abdollahisharif, J.; Aminzadeh, A.

    2017-01-01

    This research introduces a stochastic mathematical model that uses open pit long-term production planning on an integrated open pit and underground block model to determine the optimal time for transition from open pit to underground mining. In the model, ore grade is considered a random parameter in objective function and ore grade blending constraints. The objective function is modelled as the maximization of net present value in the mode of non-simultaneous combined open pit and undergroun...

  20. Identifiability analysis of rotational diffusion tensor and electronic transition moments measured in time-resolved fluorescence depolarization experiment

    International Nuclear Information System (INIS)

    Szubiakowski, Jacek P.

    2014-01-01

    The subject of this paper is studies of the deterministic identifiability of molecular parameters, such as rotational diffusion tensor components and orientation of electronic transition moments, resulting from the time-resolved fluorescence anisotropy experiment. In the most general case considered, a pair of perpendicularly polarized emissions enables the unique determination of all the rotational diffusion tensor's principal components. The influence of the tensor's symmetry and the associated degeneration of its eigenvalues on the identifiability of the electronic transitions moments is systematically investigated. The analysis reveals that independently of the rotational diffusion tensor's symmetry, the transition moments involved in photoselection and emission processes cannot be uniquely identified without a priori information about their mutual orientation or their orientation with respect to the principal axes of the tensor. Moreover, it is shown that increasing the symmetry of the rotational diffusion tensor deteriorates the degree of the transition moments identifiability. To obtain these results analytically, a novel approach to solve bilinear system of equations for Markov parameters is applied. The effect of the additional information, obtained from fluorescence measurements for different molecular mobilities, to improve the identifiability at various levels of analysis is shown. The effectiveness and reliability of the target analysis method for experimental determination of the molecular parameters is also discussed

  1. Sleep discontinuity and impaired sleep continuity affect transition to and from obesity over time: results from the Alameda county study.

    Science.gov (United States)

    Nordin, Maria; Kaplan, Robert M

    2010-03-01

    To investigate the impact of development in sleep continuity on transition to and from obesity over time. The study used self-reported sleep and body mass index (BMI) measures from the 1965, 1974, 1983, and 1994 waves of the longitudinal Alameda County Study. Sleep continuity was assessed by a question on whether the participants had any troubles falling or staying asleep. Change in sleep and BMI were estimated from the sleep and BMI questions in 1965 and 1994 respectively. Multinomial regression analyses were used to examine the risk/chance for a transition to and from obesity (BMI >or=30 kg/m(2)) due to development in sleep continuity. After adjustment for confounding variables, consistent sleep discontinuity both increases the risk for a transition to obesity and reduces the chance of losing weight, whereas impaired sleep continuity lowers the chance for weight loss. Effects for obesity were non-significant for those with improved sleep continuity. Consistent sleep discontinuity and impaired sleep continuity increases the risk of transition to obesity or of remaining obese.

  2. Ages and transit times as important diagnostics of model performance for predicting carbon dynamics in terrestrial vegetation models

    Science.gov (United States)

    Ceballos-Núñez, Verónika; Richardson, Andrew D.; Sierra, Carlos A.

    2018-03-01

    The global carbon cycle is strongly controlled by the source/sink strength of vegetation as well as the capacity of terrestrial ecosystems to retain this carbon. These dynamics, as well as processes such as the mixing of old and newly fixed carbon, have been studied using ecosystem models, but different assumptions regarding the carbon allocation strategies and other model structures may result in highly divergent model predictions. We assessed the influence of three different carbon allocation schemes on the C cycling in vegetation. First, we described each model with a set of ordinary differential equations. Second, we used published measurements of ecosystem C compartments from the Harvard Forest Environmental Measurement Site to find suitable parameters for the different model structures. And third, we calculated C stocks, release fluxes, radiocarbon values (based on the bomb spike), ages, and transit times. We obtained model simulations in accordance with the available data, but the time series of C in foliage and wood need to be complemented with other ecosystem compartments in order to reduce the high parameter collinearity that we observed, and reduce model equifinality. Although the simulated C stocks in ecosystem compartments were similar, the different model structures resulted in very different predictions of age and transit time distributions. In particular, the inclusion of two storage compartments resulted in the prediction of a system mean age that was 12-20 years older than in the models with one or no storage compartments. The age of carbon in the wood compartment of this model was also distributed towards older ages, whereas fast cycling compartments had an age distribution that did not exceed 5 years. As expected, models with C distributed towards older ages also had longer transit times. These results suggest that ages and transit times, which can be indirectly measured using isotope tracers, serve as important diagnostics of model structure

  3. Concentric Crater Fill in Utopia Planitia: Timing and Transitions Between Glacial and Periglacial Processes.

    Science.gov (United States)

    Levy, J.; Head, J.

    2008-09-01

    the contact between BT and BTC units, particularly in topographic lows between FBT-covered ridges and surrounding isolated FBT-covered hills embayed by BTC material. Brain Terrain Covering (BTC) Polygon Morphology Polygonally patterned ground present in proximity to BT, and commonly overlying it, constitutes the brain terrain covering (BTC) unit.. BTC polygons have two distinct morphologies: high centred (HC-BTC) and low centred (LC-BTC) (Figure 1). High centred BTC polygons (HCBTC) are composed of depressed surface troughs which intersect at both near-orthogonal and near-hexagonal intersections, forming polygons that are topographically high relative to their boundaries. HC-BTC polygons are commonly ~10 m in diameter, and have little topographic relief, although most have slightly convex-up interiors, based on shadow observations. HC-BTC troughs are commonly ~2-3 m across. HC-BTC polygons are present in a unit which has a lower albedo than brain terrain, and which can be up to ~40 m thick, based on MOLA point measurements. The BTC unit is generally flat, and is bounded by gently sloping margins, as well as by steeplyscarped, scalloped margins. Low centred BTC polygons (LC-BTC) are composed of troughs with raised shoulders that intersect at near-orthogonal and near-hexagonal intersections, forming polygons with depressed centres, relative to the raised rims. LC-BTC polygons are commonly ~10 m in diameter, and have smooth, flat, depressed interiors. LC-BTC polygon shouldered troughs are commonly ~3-4 m wide. LC-BTC are found at the fringes of the BTC unit, at both low-angle and scalloped margins. Spatial Relationships Between Units FBT surfaces are much more common than HBT surfaces, and HC-BTC surfaces are much more common than LCBTC surfaces. Contacts between FBT and HBT are gradational, consisting of FBT mounds which are partially hollow, or which transition into HBT-like boundary bands. Contacts between HC-BTC and LC-BTC are gradational on gentle slopes, and abrupt

  4. Dynamic measurements of reflux for quantifying gastroesophageal reflux in patients with prolonged esophageal transit time

    International Nuclear Information System (INIS)

    Gratz, K.F.; Creutzig, H.; Schmiedt, W.; Oelert, H.; Hundeshagen, H.; Medizinische Hochschule Hannover

    1985-01-01

    A combination of a radionuclide transit test and a dynamic gastroesophageal scan was evaluated in normal volunteers, in patients with achalasia treated by pneumatic dilatation (n=34) or Heller myotomy (n=21). Interpretation of 31 of 57 examinations done with usual scintiscan was not possible because of too high esophageal tracer retention. Only one case could not be interpreted with the modified technique. Gastroesophageal reflux was detected and quantified in this manner in 8 patients, 6 more than with the usual scintiscan. 7 of these 8 patients have had Heller procedure, 1 patient even combined with fundoplasty. (orig.) [de

  5. Effect of aging time on a glass transition of amorphous polymers at heating

    Czech Academy of Sciences Publication Activity Database

    Hadač, J.; Říha, Pavel; Slobodian, P.; Saha, P.; Kubát, J.

    2014-01-01

    Roč. 108, special issue 1 (2014), s. 59-65 ISSN 0009-2770 Grant - others:GA MŠk(CZ) EE.2.3.20.0104; GA MŠk(CZ) ED2.1.00/03.0111 Institutional research plan: CEZ:AV0Z20600510 Institutional support: RVO:67985874 Keywords : physical aging * glass transition * PMMA * relaxation function Subject RIV: BK - Fluid Dynamics Impact factor: 0.272, year: 2014 http://www.chemicke-listy.cz/docs/full/2014_s1_s59-s65.pdf

  6. Surface hopping, transition state theory and decoherence. I. Scattering theory and time-reversibility.

    Science.gov (United States)

    Jain, Amber; Herman, Michael F; Ouyang, Wenjun; Subotnik, Joseph E

    2015-10-07

    We provide an in-depth investigation of transmission coefficients as computed using the augmented-fewest switches surface hopping algorithm in the low energy regime. Empirically, microscopic reversibility is shown to hold approximately. Furthermore, we show that, in some circumstances, including decoherence on top of surface hopping calculations can help recover (as opposed to destroy) oscillations in the transmission coefficient as a function of energy; these oscillations can be studied analytically with semiclassical scattering theory. Finally, in the spirit of transition state theory, we also show that transmission coefficients can be calculated rather accurately starting from the curve crossing point and running trajectories forwards and backwards.

  7. Dynamic measurements of reflux for quantifying gastroesophageal reflux in patients with prolonged esophageal transit time

    Energy Technology Data Exchange (ETDEWEB)

    Gratz, K.F.; Creutzig, H.; Schmiedt, W.; Oelert, H.; Hundeshagen, H.

    1985-05-01

    A combination of a radionuclide transit test and a dynamic gastroesophageal scan was evaluated in normal volunteers, in patients with achalasia treated by pneumatic dilatation (n=34) or Heller myotomy (n=21). Interpretation of 31 of 57 examinations done with usual scintiscan was not possible because of too high esophageal tracer retention. Only one case could not be interpreted with the modified technique. Gastroesophageal reflux was detected and quantified in this manner in 8 patients, 6 more than with the usual scintiscan. 7 of these 8 patients have had Heller procedure, 1 patient even combined with fundoplasty.

  8. Tc-99m-Human Serum Albumin Transit Time as a Measure of Arm Breast Cancer-Related Lymphedema

    DEFF Research Database (Denmark)

    Toyserkani, Navid M; Hvidsten, Svend; Tabatabaeifar, Siavosh

    2017-01-01

    34-68 years, with unilateral arm lymphedema following breast cancer treatment underwent bilateral lymphoscintigraphy using intradermal injection in both hands of technetium-99m-labeled human serum albumin and sequential 5 min imaging for 5 hours. The mean transit time (MTT) in the arms was calculated...... based on time activity curves generated from injection site and arm regions. Visual lymphedema scoring was performed based on dermal backflow and lymph node presence. Excess arm volume was calculated from circumference measurements. RESULTS: The MTT (mean ± SD) was significantly longer in the lymphedema...

  9. Prolonged transition time between colostrum and mature milk in a bear, the giant panda, Ailuropoda melanoleuca

    Science.gov (United States)

    Griffiths, Kate; Hou, Rong; Wang, Hairui; Zhang, Zhihe; Zhang, Liang; Zhang, Tong; Watson, David G.; Burchmore, Richard J. S.; Loeffler, I. Kati; Kennedy, Malcolm W.

    2015-01-01

    Bears produce the most altricial neonates of any placental mammal. We hypothesized that the transition from colostrum to mature milk in bears reflects a temporal and biochemical adaptation for altricial development and immune protection. Comparison of bear milks with milks of other eutherians yielded distinctive protein profiles. Proteomic and metabolomic analysis of serial milk samples collected from six giant pandas showed a prolonged transition from colostrum to main-phase lactation over approximately 30 days. Particularly striking are the persistence or sequential appearance of adaptive and innate immune factors. The endurance of immunoglobulin G suggests an unusual duration of trans-intestinal absorption of maternal antibodies, and is potentially relevant to the underdeveloped lymphoid system of giant panda neonates. Levels of certain milk oligosaccharides known to exert anti-microbial activities and/or that are conducive to the development of neonatal gut microbiomes underwent an almost complete changeover around days 20–30 postpartum, coincident with the maturation of the protein profile. A potential metabolic marker of starvation was detected, the prominence of which may reflect the natural postpartum period of anorexia in giant panda mothers. Early lactation in giant pandas, and possibly in other ursids, appears to be adapted for the unique requirements of unusually altricial eutherian neonates. PMID:26587250

  10. Decay times of transitionally dense specularly reflecting meteor trails and potential chemical impact on trail lifetimes

    Directory of Open Access Journals (Sweden)

    W. K. Hocking

    2016-12-01

    Full Text Available Studies of transitionally dense meteor trails using radars which employ specularly reflecting interferometric techniques are used to show that measurable high-temperature chemistry exists at timescales of a few tenths of a second after the formation of these trails. This is a process which is distinct from the ambient-temperature chemistry that is already known to exist at timescales of tens of seconds and longer in long-lived trails. As a consequence, these transitionally dense trails have smaller lifetimes than might be expected if diffusion were the only mechanism for reducing the mean trail electron density. The process has been studied with four SKiYMET radars at latitudes varying from 10 to 75° N, over a period of more than 10 years, 24 h per day. In this paper we present the best parameters to use to represent this behaviour and demonstrate the characteristics of the temporal and latitudinal variability in these parameters. The seasonal, day–night and latitudinal variations correlate reasonably closely with the corresponding variations of ozone in the upper mesosphere. Possible reasons for these effects are discussed, but further investigations of any causative relation are still the subject of ongoing studies.

  11. Performance Analysis of Stop-Skipping Scheduling Plans in Rail Transit under Time-Dependent Demand.

    Science.gov (United States)

    Cao, Zhichao; Yuan, Zhenzhou; Zhang, Silin

    2016-07-13

    Stop-skipping is a key method for alleviating congestion in rail transit, where schedules are sometimes difficult to implement. Several mechanisms have been proposed and analyzed in the literature, but very few performance comparisons are available. This study formulated train choice behavior estimation into the model considering passengers' perception. If a passenger's train path can be identified, this information would be useful for improving the stop-skipping schedule service. Multi-performance is a key characteristic of our proposed five stop-skipping schedules, but quantified analysis can be used to illustrate the different effects of well-known deterministic and stochastic forms. Problems in the novel category of forms were justified in the context of a single line rather than transit network. We analyzed four deterministic forms based on the well-known A/B stop-skipping operating strategy. A stochastic form was innovatively modeled as a binary integer programming problem. We present a performance analysis of our proposed model to demonstrate that stop-skipping can feasibly be used to improve the service of passengers and enhance the elasticity of train operations under demand variations along with an explicit parametric discussion.

  12. Performance Analysis of Stop-Skipping Scheduling Plans in Rail Transit under Time-Dependent Demand

    Directory of Open Access Journals (Sweden)

    Zhichao Cao

    2016-07-01

    Full Text Available Stop-skipping is a key method for alleviating congestion in rail transit, where schedules are sometimes difficult to implement. Several mechanisms have been proposed and analyzed in the literature, but very few performance comparisons are available. This study formulated train choice behavior estimation into the model considering passengers’ perception. If a passenger’s train path can be identified, this information would be useful for improving the stop-skipping schedule service. Multi-performance is a key characteristic of our proposed five stop-skipping schedules, but quantified analysis can be used to illustrate the different effects of well-known deterministic and stochastic forms. Problems in the novel category of forms were justified in the context of a single line rather than transit network. We analyzed four deterministic forms based on the well-known A/B stop-skipping operating strategy. A stochastic form was innovatively modeled as a binary integer programming problem. We present a performance analysis of our proposed model to demonstrate that stop-skipping can feasibly be used to improve the service of passengers and enhance the elasticity of train operations under demand variations along with an explicit parametric discussion.

  13. Prolonged transition time between colostrum and mature milk in a bear, the giant panda, Ailuropoda melanoleuca.

    Science.gov (United States)

    Griffiths, Kate; Hou, Rong; Wang, Hairui; Zhang, Zhihe; Zhang, Liang; Zhang, Tong; Watson, David G; Burchmore, Richard J S; Loeffler, I Kati; Kennedy, Malcolm W

    2015-10-01

    Bears produce the most altricial neonates of any placental mammal. We hypothesized that the transition from colostrum to mature milk in bears reflects a temporal and biochemical adaptation for altricial development and immune protection. Comparison of bear milks with milks of other eutherians yielded distinctive protein profiles. Proteomic and metabolomic analysis of serial milk samples collected from six giant pandas showed a prolonged transition from colostrum to main-phase lactation over approximately 30 days. Particularly striking are the persistence or sequential appearance of adaptive and innate immune factors. The endurance of immunoglobulin G suggests an unusual duration of trans-intestinal absorption of maternal antibodies, and is potentially relevant to the underdeveloped lymphoid system of giant panda neonates. Levels of certain milk oligosaccharides known to exert anti-microbial activities and/or that are conducive to the development of neonatal gut microbiomes underwent an almost complete changeover around days 20-30 postpartum, coincident with the maturation of the protein profile. A potential metabolic marker of starvation was detected, the prominence of which may reflect the natural postpartum period of anorexia in giant panda mothers. Early lactation in giant pandas, and possibly in other ursids, appears to be adapted for the unique requirements of unusually altricial eutherian neonates.

  14. Shape effects on time-scale divergence at athermal jamming transition of frictionless non-spherical particles

    Science.gov (United States)

    Yuan, Ye; Jin, Weiwei; Liu, Lufeng; Li, Shuixiang

    2017-10-01

    The critical behaviors of a granular system at the jamming transition have been extensively studied from both mechanical and thermodynamic perspectives. In this work, we numerically investigate the jamming behaviors of a variety of frictionless non-spherical particles, including spherocylinder, ellipsoid, spherotetrahedron and spherocube. In particular, for a given particle shape, a series of random configurations at different fixed densities are generated and relaxed to minimize interparticle overlaps using the relaxation algorithm. We find that as the jamming point (i.e., point J) is approached, the number of iteration steps (defined as the "time-scale" for our systems) required to completely relax the interparticle overlaps exhibits a clear power-law divergence. The dependence of the detailed mathematical form of the power-law divergence on particle shapes is systematically investigated and elucidated, which suggests that the shape effects can be generally categorized as elongation and roundness. Importantly, we show the jamming transition density can be accurately determined from the analysis of time-scale divergence for different non-spherical shapes, and the obtained values agree very well with corresponding ones reported in literature. Moreover, we study the plastic behaviors of over-jammed packings of different particles under a compression-expansion procedure and find that the jamming of ellipsoid is much more robust than other non-spherical particles. This work offers an alternative approximate procedure besides conventional packing algorithms for studying athermal jamming transition in granular system of frictionless non-spherical particles.

  15. Kinetics of the main phase transition of hydrated lecithin monitored by real-time x-ray diffraction

    International Nuclear Information System (INIS)

    Caffrey, M.; Bilderback, D.H.

    1984-01-01

    A method is described for observing and recording in real-time x-ray diffraction from an unoriented hydrated membrane lipid, dipalmitoylphosphatidylcholine (DPPC), through its thermotropic gel/liquid crystal phase transition. Synchrotron radiation from the Cornell High Energy Synchrotron Source (Ithaca, New York) was used as an x-ray source of extremely high brilliance and the dynamic display of the diffraction image was effected using a three-stage image intensifier tube coupled to an external fluorescent screen. The image on the output phosphor was sufficiently intense to be recorded cinematographically and to be displayed on a television monitor using a vidicon camera at 30 frames x s -1 . These measurements set an upper limit of 2 s on the DPPC gel → liquid crystal phase transition and indicate that the transition is a two-state process. The real-time method couples the power of x-ray diffraction as a structural probe with the ability to follow kinetics of structural changes. The method does not require an exogenous probe, is relatively nonperturbing, and can be used with membranes in a variety of physical states and with unstable samples. The method has the additional advantage over its static measurement counterpart in that it is more likely to detect transiently stable intermediates if present

  16. Radiographic anatomy and barium sulfate contrast transit time of the gastrointestinal tract of bearded dragons (Pogona vitticeps).

    Science.gov (United States)

    Grosset, Claire; Daniaux, Lise; Guzman, David Sanchez-Migallon; Weber, Ernest Scott; Zwingenberger, Allison; Paul-Murphy, Joanne

    2014-01-01

    The positive contrast gastrointestinal study is a common non-invasive diagnostic technique that does not require anesthesia and enables good visualization of the digestive tract. Radiographic anatomy and reference intervals for gastrointestinal contrast transit time in inland bearded dragons (Pogona vitticeps) were established using seven animals administered 15 ml/kg of a 35% w/v suspension of barium by esophageal gavage. Dorso-ventral and lateral radiographic views were performed at 0, 15, 30 min, 1, 2, 4, 6, 8, 12 h, and then every 12 h up to 96 h after barium administration. Gastric emptying was complete at a median time of 10 h (range 4-24 h). Median jejunum and small intestinal emptying times were 1 h (range 30 min-2 h) and 29 h (range 24-48 h), respectively. Median transit time for cecum was 10 h (range 8-12 h). Median time for contrast to reach the colon was 31 h (range 12-72 h) after administration. Results were compared to those obtained in other reptilian species. This technique appeared safe in fasted bearded dragons and would be clinically applicable in other lizard species.

  17. Time Delay and Long-Range Connection Induced Synchronization Transitions in Newman-Watts Small-World Neuronal Networks

    Science.gov (United States)

    Qian, Yu

    2014-01-01

    The synchronization transitions in Newman-Watts small-world neuronal networks (SWNNs) induced by time delay and long-range connection (LRC) probability have been investigated by synchronization parameter and space-time plots. Four distinct parameter regions, that is, asynchronous region, transition region, synchronous region, and oscillatory region have been discovered at certain LRC probability as time delay is increased. Interestingly, desynchronization is observed in oscillatory region. More importantly, we consider the spatiotemporal patterns obtained in delayed Newman-Watts SWNNs are the competition results between long-range drivings (LRDs) and neighboring interactions. In addition, for moderate time delay, the synchronization of neuronal network can be enhanced remarkably by increasing LRC probability. Furthermore, lag synchronization has been found between weak synchronization and complete synchronization as LRC probability is a little less than 1.0. Finally, the two necessary conditions, moderate time delay and large numbers of LRCs, are exposed explicitly for synchronization in delayed Newman-Watts SWNNs. PMID:24810595

  18. Probing Photoinduced Structural Phase Transitions by Fast or Ultra-Fast Time-Resolved X-Ray Diffraction

    Science.gov (United States)

    Cailleau, Hervé Collet, Eric; Buron-Le Cointe, Marylise; Lemée-Cailleau, Marie-Hélène Koshihara, Shin-Ya

    A new frontier in the field of structural science is the emergence of the fast and ultra-fast X-ray science. Recent developments in time-resolved X-ray diffraction promise direct access to the dynamics of electronic, atomic and molecular motions in condensed matter triggered by a pulsed laser irradiation, i.e. to record "molecular movies" during the transformation of matter initiated by light pulse. These laser pump and X-ray probe techniques now provide an outstanding opportunity for the direct observation of a photoinduced structural phase transition as it takes place. The use of X-ray short-pulse of about 100ps around third-generation synchrotron sources allows structural investigations of fast photoinduced processes. Other new X-ray sources, such as laser-produced plasma ones, generate ultra-short pulses down to 100 fs. This opens the way to femtosecond X-ray crystallography, but with rather low X-ray intensities and more limited experimental possibilities at present. However this new ultra-fast science rapidly progresses around these sources and new large-scale projects exist. It is the aim of this contribution to overview the state of art and the perspectives of fast and ultra-fast X-ray scattering techniques to study photoinduced phase transitions (here, the word ultra-fast is used for sub-picosecond time resolution). In particular we would like to largely present the contribution of crystallographic methods in comparison with optical methods, such as pump-probe reflectivity measurements, the reader being not necessary familiar with X-ray scattering. Thus we want to presen