Sleep, performance, and plasma levels in chronic insomniacs during 14-day use of flurazepam and midazolam: an introduction.

PubMed

Johnson, L C; Chernik, D A; Sateia, M J

1990-08-01

A review of the published literature reveals many unanswered questions regarding the effects of sedative-hypnotics on sleep, performance, and mood. The relationship between plasma half-life and hypnotic efficacy is also not clear. A randomized, double-blind, parallel-groups, multicenter study was designed to examine sleep, performance, and mood in patients with insomnia. A large, heterogeneous sample of patients with a history of benzodiazepine use for chronic insomnia was chosen to reflect the adult population for which sedative-hypnotics are often prescribed and to ensure statistical reliability. Although the major focus of the current study was on the effects of two benzodiazepine hypnotics on performance, this study also provided information on the following important issues: (1) effect of dose level; (2) short-versus long-term administration; and (3) significance of plasma half-life as it relates to hypnotic efficacy.

An international randomized study of a home-based self-management program for severe COPD: the COMET.

PubMed

Bourbeau, Jean; Casan, Pere; Tognella, Silvia; Haidl, Peter; Texereau, Joëlle B; Kessler, Romain

2016-01-01

Most hospitalizations and costs related to COPD are due to exacerbations and insufficient disease management. The COPD patient Management European Trial (COMET) is investigating a home-based multicomponent COPD self-management program designed to reduce exacerbations and hospital admissions. Multicenter parallel randomized controlled, open-label superiority trial. Thirty-three hospitals in four European countries. A total of 345 patients with Global initiative for chronic Obstructive Lung Disease III/IV COPD. The program includes extensive patient coaching by health care professionals to improve self-management (eg, develop skills to better manage their disease), an e-health platform for reporting frequent health status updates, rapid intervention when necessary, and oxygen therapy monitoring. Comparator is the usual management as per the center's routine practice. Yearly number of hospital days for acute care, exacerbation number, quality of life, deaths, and costs.

Improvement in Growth After 1 Year of Growth Hormone Therapy in Well-Nourished Infants with Growth Retardation Secondary to Chronic Renal Failure: Results of a Multicenter, Controlled, Randomized, Open Clinical Trial

PubMed Central

Moreno, M. Llanos; Neto, Arlete; Ariceta, Gema; Vara, Julia; Alonso, Angel; Bueno, Alberto; Afonso, Alberto Caldas; Correia, António Jorge; Muley, Rafael; Barrios, Vicente; Gómez, Carlos; Argente, Jesús

2010-01-01

Background and objectives: Our aim was to evaluate the growth-promoting effect of growth hormone (GH) treatment in infants with chronic renal failure (CRF) and persistent growth retardation despite adequate nutritional and metabolic management. Design, setting, participants, & measurements: The study design included randomized, parallel groups in an open, multicenter trial comparing GH (0.33 mg/kg per wk) with nontreatment with GH during 12 months. Sixteen infants who had growth retardation, were aged 12 ± 3 months, had CRF (GFR ≤60 ml/min per 1.73 m2), and had adequate nutritional intake and good metabolic control were recruited from eight pediatric nephrology departments from Spain and Portugal. Main outcome measures were body length, body weight, bone age, biochemical and hormonal analyses, renal function, bone mass, and adverse effects. Results: Length gain in infants who were treated with GH was statistically greater (P < 0.05) than that of nontreated children (14.5 versus 9.5 cm/yr; SD score 1.43 versus −0.11). The GH-induced stimulation of growth was associated with no undesirable effects on bone maturation, renal failure progression, or metabolic control. In addition, GH treatment improved forearm bone mass and increased serum concentrations of total and free IGF-I and IGF-binding protein 3 (IGFBP-3), whereas IGF-II, IGFBP-1, IGFBP-2, GH-binding protein, ghrelin, and leptin were not modified. Conclusions: Infants with CRF and growth retardation despite good metabolic and nutritional control benefit from GH treatment without adverse effects during 12 months of therapy. PMID:20522533

Acute cholecystitis in high risk surgical patients: percutaneous cholecystostomy versus laparoscopic cholecystectomy (CHOCOLATE trial): Study protocol for a randomized controlled trial

PubMed Central

2012-01-01

Background Laparoscopic cholecystectomy in acute calculous cholecystitis in high risk patients can lead to significant morbidity and mortality. Percutaneous cholecystostomy may be an alternative treatment option but the current literature does not provide the surgical community with evidence based advice. Methods/Design The CHOCOLATE trial is a randomised controlled, parallel-group, superiority multicenter trial. High risk patients, defined as APACHE-II score 7-14, with acute calculous cholecystitis will be randomised to laparoscopic cholecystectomy or percutaneous cholecystostomy. During a two year period 284 patients will be enrolled from 30 high volume teaching hospitals. The primary endpoint is a composite endpoint of major complications within three months following randomization and need for re-intervention and mortality during the follow-up period of one year. Secondary endpoints include all other complications, duration of hospital admission, difficulty of procedures and total costs. Discussion The CHOCOLATE trial is designed to provide the surgical community with an evidence based guideline in the treatment of acute calculous cholecystitis in high risk patients. Trial Registration Netherlands Trial Register (NTR): NTR2666 PMID:22236534

Impact of the Patient-Reported Outcomes Management Information System (PROMIS) upon the design and operation of multi-center clinical trials: a qualitative research study.

PubMed

Eisenstein, Eric L; Diener, Lawrence W; Nahm, Meredith; Weinfurt, Kevin P

2011-12-01

New technologies may be required to integrate the National Institutes of Health's Patient Reported Outcome Management Information System (PROMIS) into multi-center clinical trials. To better understand this need, we identified likely PROMIS reporting formats, developed a multi-center clinical trial process model, and identified gaps between current capabilities and those necessary for PROMIS. These results were evaluated by key trial constituencies. Issues reported by principal investigators fell into two categories: acceptance by key regulators and the scientific community, and usability for researchers and clinicians. Issues reported by the coordinating center, participating sites, and study subjects were those faced when integrating new technologies into existing clinical trial systems. We then defined elements of a PROMIS Tool Kit required for integrating PROMIS into a multi-center clinical trial environment. The requirements identified in this study serve as a framework for future investigators in the design, development, implementation, and operation of PROMIS Tool Kit technologies.

Impact of the Patient-Reported Outcomes Management Information System (PROMIS) upon the Design and Operation of Multi-center Clinical Trials: a Qualitative Research Study

PubMed Central

Diener, Lawrence W.; Nahm, Meredith; Weinfurt, Kevin P.

2013-01-01

New technologies may be required to integrate the National Institutes of Health’s Patient Reported Outcome Management Information System (PROMIS) into multi-center clinical trials. To better understand this need, we identified likely PROMIS reporting formats, developed a multi-center clinical trial process model, and identified gaps between current capabilities and those necessary for PROMIS. These results were evaluated by key trial constituencies. Issues reported by principal investigators fell into two categories: acceptance by key regulators and the scientific community, and usability for researchers and clinicians. Issues reported by the coordinating center, participating sites, and study subjects were those faced when integrating new technologies into existing clinical trial systems. We then defined elements of a PROMIS Tool Kit required for integrating PROMIS into a multi-center clinical trial environment. The requirements identified in this study serve as a framework for future investigators in the design, development, implementation, and operation of PROMIS Tool Kit technologies. PMID:20703765

The NEtherlands Cervical Kinematics (NECK) Trial. Cost-effectiveness of anterior cervical discectomy with or without interbody fusion and arthroplasty in the treatment of cervical disc herniation; a double-blind randomised multicenter study

PubMed Central

2010-01-01

Background Patients with cervical radicular syndrome due to disc herniation refractory to conservative treatment are offered surgical treatment. Anterior cervical discectomy is the standard procedure, often in combination with interbody fusion. Accelerated adjacent disc degeneration is a known entity on the long term. Recently, cervical disc prostheses are developed to maintain motion and possibly reduce the incidence of adjacent disc degeneration. A comparative cost-effectiveness study focused on adjacent segment degeneration and functional outcome has not been performed yet. We present the design of the NECK trial, a randomised study on cost-effectiveness of anterior cervical discectomy with or without interbody fusion and arthroplasty in patients with cervical disc herniation. Methods/Design Patients (age 18-65 years) presenting with radicular signs due to single level cervical disc herniation lasting more than 8 weeks are included. Patients will be randomised into 3 groups: anterior discectomy only, anterior discectomy with interbody fusion, and anterior discectomy with disc prosthesis. The primary outcome measure is symptomatic adjacent disc degeneration at 2 and 5 years after surgery. Other outcome parameters will be the Neck Disability Index, perceived recovery, arm and neck pain, complications, re-operations, quality of life, job satisfaction, anxiety and depression assessment, medical consumption, absenteeism, and costs. The study is a randomised prospective multicenter trial, in which 3 surgical techniques are compared in a parallel group design. Patients and research nurses will be kept blinded of the allocated treatment for 2 years. The follow-up period is 5 years. Discussion Currently, anterior cervical discectomy with fusion is the golden standard in the surgical treatment of cervical disc herniation. Whether additional interbody fusion or disc prothesis is necessary and cost-effective will be determined by this trial. Trial Registration Netherlands Trial Register NTR1289 PMID:20553591

Efficacy and safety of sacubitril/valsartan (LCZ696) in Japanese patients with chronic heart failure and reduced ejection fraction: Rationale for and design of the randomized, double-blind PARALLEL-HF study.

PubMed

Tsutsui, Hiroyuki; Momomura, Shinichi; Saito, Yoshihiko; Ito, Hiroshi; Yamamoto, Kazuhiro; Ohishi, Tomomi; Okino, Naoko; Guo, Weinong

2017-09-01

The prognosis of heart failure patients with reduced ejection fraction (HFrEF) in Japan remains poor, although there is growing evidence for increasing use of evidence-based pharmacotherapies in Japanese real-world HF registries. Sacubitril/valsartan (LCZ696) is a first-in-class angiotensin receptor neprilysin inhibitor shown to reduce mortality and morbidity in the recently completed largest outcome trial in patients with HFrEF (PARADIGM-HF trial). The prospectively designed phase III PARALLEL-HF (Prospective comparison of ARNI with ACE inhibitor to determine the noveL beneficiaL trEatment vaLue in Japanese Heart Failure patients) study aims to assess the clinical efficacy and safety of LCZ696 in Japanese HFrEF patients, and show similar improvements in clinical outcomes as the PARADIGM-HF study enabling the registration of LCZ696 in Japan. This is a multicenter, randomized, double-blind, parallel-group, active controlled study of 220 Japanese HFrEF patients. Eligibility criteria include a diagnosis of chronic HF (New York Heart Association Class II-IV) and reduced ejection fraction (left ventricular ejection fraction ≤35%) and increased plasma concentrations of natriuretic peptides [N-terminal pro B-type natriuretic peptide (NT-proBNP) ≥600pg/mL, or NT-proBNP ≥400pg/mL for those who had a hospitalization for HF within the last 12 months] at the screening visit. The study consists of three phases: (i) screening, (ii) single-blind active LCZ696 run-in, and (iii) double-blind randomized treatment. Patients tolerating LCZ696 50mg bid during the treatment run-in are randomized (1:1) to receive LCZ696 100mg bid or enalapril 5mg bid for 4 weeks followed by up-titration to target doses of LCZ696 200mg bid or enalapril 10mg bid in a double-blind manner. The primary outcome is the composite of cardiovascular death or HF hospitalization and the study is an event-driven trial. The design of the PARALLEL-HF study is aligned with the PARADIGM-HF study and aims to assess the efficacy and safety of LCZ696 in Japanese HFrEF patients. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Study protocol of Prednisone in episodic Cluster Headache (PredCH): a randomized, double-blind, placebo-controlled parallel group trial to evaluate the efficacy and safety of oral prednisone as an add-on therapy in the prophylactic treatment of episodic cluster headache with verapamil

PubMed Central

2013-01-01

Background Episodic cluster headache (ECH) is a primary headache disorder that severely impairs patient’s quality of life. First-line therapy in the initiation of a prophylactic treatment is verapamil. Due to its delayed onset of efficacy and the necessary slow titration of dosage for tolerability reasons prednisone is frequently added by clinicians to the initial prophylactic treatment of a cluster episode. This treatment strategy is thought to effectively reduce the number and intensity of cluster attacks in the beginning of a cluster episode (before verapamil is effective). This study will assess the efficacy and safety of oral prednisone as an add-on therapy to verapamil and compare it to a monotherapy with verapamil in the initial prophylactic treatment of a cluster episode. Methods and design PredCH is a prospective, randomized, double-blind, placebo-controlled trial with parallel study arms. Eligible patients with episodic cluster headache will be randomized to a treatment intervention with prednisone or a placebo arm. The multi-center trial will be conducted in eight German headache clinics that specialize in the treatment of ECH. Discussion PredCH is designed to assess whether oral prednisone added to first-line agent verapamil helps reduce the number and intensity of cluster attacks in the beginning of a cluster episode as compared to monotherapy with verapamil. Trial registration German Clinical Trials Register DRKS00004716 PMID:23889923

Comparative efficacy and safety of two 0.025% tretinoin gels: results from a multicenter double-blind, parallel study.

PubMed

Lucky, A W; Cullen, S I; Jarratt, M T; Quigley, J W

1998-04-01

The addition of polyolprepolymer-2 in tretinoin formulations may reduce tretinoin-induced cutaneous irritation. This study compared the efficacy and safety of a new 0.025% tretinoin gel containing polyolprepolymer-2, its vehicle, and a commercially-available 0.025% tretinoin gel in patients with mild to moderate acne vulgaris. In this 12-week multicenter, double-blind, parallel group study, efficacy was evaluated by objective lesion counts and the investigators' global evaluations. Subjective assessment of cutaneous irritation by the investigators and patients evaluated safety. The efficacy of the two active treatments in this 215 patient study was comparable, and both treatments were statistically significantly more effective than vehicle. When compared with the commercially-available tretinoin gel, the formulation containing polyolprepolymer-2 demonstrated statistically significantly less peeling at days 28, 56, and 84, statistically significantly less dryness by day 84, and statistically significantly less itching at day 14. Irritation scores for the formulation containing polyolprepolymer-2 were numerically lower but not statistically different from those of the commercially-available gel for erythema and burning. The number of cutaneous and noncutaneous adverse events were similar for both active medications. The two 0.025% gels studied demonstrated comparable efficacy. However, the gel formulation containing polyolprepolymer-2 caused significantly less peeling and drying than the commercially-available formulation by day 84 of the study.

Conjugation in multi-tetrazole derivatives: a new design direction for energetic materials.

PubMed

Sun, Shuyang; Lu, Ming

2018-06-23

Multi-tetrazole derivatives with conjugated structures were designed and investigated in this study. Using quantum chemistry methods, the crystal structures, electrostatic potentials (ESPs), multicenter bond orders, HOMO-LUMO energy gaps, and detonation properties of the derivatives were calculated. As expected, these molecules with conjugated structures showed low energies of their crystal structures, molecular layering in their crystals, high average ESPs, high multicenter bond order values, and enhanced detonation properties. The derivative 1,2-di(1H-tetrazol-5-yl)diazene (N2) was predicted to have the best density (1.87 g/cm 3 ), detonation velocity (9006 m/s), and detonation pressure (36.8 GPa) of the designed molecules, while its total crystal energy was low, suggesting that it is relatively stable. Its sensitivity was also low, as the molecular stacking that occurs in its crystal allows external forces to be dissipated into movements of crystal layers. Finally, its multicenter bond order was high, indicating a highly conjugated structure.

Rationale, study design, and implementation of the ACS1 study: effect of azilsartan on circadian and sleep blood pressure as compared with amlodipine.

PubMed

Kario, Kazuomi; Hoshide, Satoshi

2014-06-01

The ACS1 (Azilsartan Circadian and Sleep Pressure - the first study) is a multicenter, randomized, open-label, two parallel-group study carried out to investigate the efficacy of an 8-week oral treatment with azilsartan 20 mg in comparison with amlodipine 5 mg. The patients with stage I or II primary hypertension will be randomly assigned to either an azilsartan group (n=350) or an amlodipine group (n=350). The primary endpoint is a change in nocturnal systolic blood pressure (BP) as measured by ambulatory BP monitoring at the end of follow-up relative to the baseline level during the run-in period. In addition, we will carry out the same analysis after dividing four different nocturnal BP dipping statuses (extreme-dippers, dippers, nondipper, and risers). The findings of this study will help in establishing an appropriate antihypertensive treatment for hypertensive patients with a disrupted circadian BP rhythm.

Rationale, study design, and implementation of the ACS1 study: effect of azilsartan on circadian and sleep blood pressure as compared with amlodipine

PubMed Central

Hoshide, Satoshi

2014-01-01

Objective The ACS1 (Azilsartan Circadian and Sleep Pressure – the first study) is a multicenter, randomized, open-label, two parallel-group study carried out to investigate the efficacy of an 8-week oral treatment with azilsartan 20 mg in comparison with amlodipine 5 mg. Materials and methods The patients with stage I or II primary hypertension will be randomly assigned to either an azilsartan group (n=350) or an amlodipine group (n=350). The primary endpoint is a change in nocturnal systolic blood pressure (BP) as measured by ambulatory BP monitoring at the end of follow-up relative to the baseline level during the run-in period. In addition, we will carry out the same analysis after dividing four different nocturnal BP dipping statuses (extreme-dippers, dippers, nondipper, and risers). Conclusion The findings of this study will help in establishing an appropriate antihypertensive treatment for hypertensive patients with a disrupted circadian BP rhythm. PMID:24637789

Multicenter AIDS Cohort Study Quantitative Coronary Plaque Progression Study: rationale and design.

PubMed

Nakanishi, Rine; Post, Wendy S; Osawa, Kazuhiro; Jayawardena, Eranthi; Kim, Michael; Sheidaee, Nasim; Nezarat, Negin; Rahmani, Sina; Kim, Nicholas; Hathiramani, Nicolai; Susarla, Shriraj; Palella, Frank; Witt, Mallory; Blaha, Michael J; Brown, Todd T; Kingsley, Lawrence; Haberlen, Sabina A; Dailing, Christopher; Budoff, Matthew J

2018-01-01

The association of HIV with coronary atherosclerosis has been established; however, the progression of coronary atherosclerosis over time among participants with HIV is not well known. The Multicenter AIDS Cohort Study Quantitative Coronary Plaque Progression Study is a large prospective multicenter study quantifying progression of coronary plaque assessed by serial coronary computed tomography angiography (CTA). HIV-infected and uninfected men who were enrolled in the Multicenter AIDS Cohort Study Cardiovascular Substudy were eligible to complete a follow-up contrast coronary CTA 3-6 years after baseline. We measured coronary plaque volume and characteristics (calcified and noncalcified plaque including fibrous, fibrous-fatty, and low attenuation) and vulnerable plaque among HIV-infected and uninfected men using semiautomated plaque software to investigate the progression of coronary atherosclerosis over time. We describe a novel, large prospective multicenter study investigating incidence, transition of characteristics, and progression in coronary atherosclerosis quantitatively assessed by serial coronary CTAs among HIV-infected and uninfected men.

MODUL-a multicenter randomized clinical trial of biomarker-driven maintenance therapy following first-line standard induction treatment of metastatic colorectal cancer: an adaptable signal-seeking approach.

PubMed

Schmoll, Hans-Joachim; Arnold, Dirk; de Gramont, Aimery; Ducreux, Michel; Grothey, Axel; O'Dwyer, Peter J; Van Cutsem, Eric; Hermann, Frank; Bosanac, Ivan; Bendahmane, Belguendouz; Mancao, Christoph; Tabernero, Josep

2018-06-01

The old approach of one therapeutic for all patients with mCRC is evolving with a need to target specific molecular aberrations or cell-signalling pathways. Molecular screening approaches and new biomarkers are required to fully characterize tumours, identify patients most likely to benefit, and predict treatment response. MODUL is a signal-seeking trial with a design that is highly adaptable, permitting modification of different treatment cohorts and inclusion of further additional cohorts based on novel evidence on new compounds/combinations that emerge during the study. MODUL is ongoing and its adaptable nature permits timely and efficient recruitment of patients into the most appropriate cohort. Recruitment will take place over approximately 5 years in Europe, Asia, Africa, and South America. The design of MODUL with ongoing parallel/sequential treatment cohorts means that the overall size and duration of the trial can be modified/prolonged based on accumulation of new data. The early success of the current trial suggests that the design may provide definitive leads in a patient-friendly and relatively economical trial structure. Along with other biomarker-driven trials that are currently underway, it is hoped that MODUL will contribute to the continuing evolution of clinical trial design and permit a more 'tailored' approach to the treatment of patients with mCRC.

Internet-delivered cognitive-behavioral treatment for adolescents with chronic pain and their parents: a randomized controlled multicenter trial.

PubMed

Palermo, Tonya M; Law, Emily F; Fales, Jessica; Bromberg, Maggie H; Jessen-Fiddick, Tricia; Tai, Gabrielle

2016-01-01

Internet-delivered interventions are emerging as a strategy to address barriers to care for individuals with chronic pain. This is the first large multicenter randomized controlled trial of Internet-delivered cognitive-behavioral therapy (CBT) for pediatric chronic pain. Participants included were 273 adolescents (205 females and 68 males), aged 11 to 17 years with mixed chronic pain conditions and their parents, who were randomly assigned in a parallel-group design to Internet-delivered CBT (n = 138) or Internet-delivered Education (n = 135). Assessments were completed before treatment, immediately after treatment, and at 6-month follow-up. All data collection and procedures took place online. The primary analysis used linear growth models. Results demonstrated significantly greater reduction on the primary outcome of activity limitations from baseline to 6-month follow-up for Internet CBT compared with Internet education (b = -1.13, P = 0.03). On secondary outcomes, significant beneficial effects of Internet CBT were found on sleep quality (b = 0.14, P = 0.04), on reducing parent miscarried helping (b = -2.66, P = 0.007) and protective behaviors (b = -0.19, P = 0.001), and on treatment satisfaction (P values < 0.05). On exploratory outcomes, benefits of Internet CBT were found for parent-perceived impact (ie, reductions in depression, anxiety, self-blame about their adolescent's pain, and improvement in parent behavioral responses to pain). In conclusion, our Internet-delivered CBT intervention produced a number of beneficial effects on adolescent and parent outcomes, and could ultimately lead to wide dissemination of evidence-based psychological pain treatment for youth and their families.

Rationale and design of the Clinical Evaluation of Magnetic Resonance Imaging in Coronary heart disease 2 trial (CE-MARC 2): A prospective, multicenter, randomized trial of diagnostic strategies in suspected coronary heart disease

PubMed Central

Ripley, David P.; Brown, Julia M.; Everett, Colin C.; Bijsterveld, Petra; Walker, Simon; Sculpher, Mark; McCann, Gerry P.; Berry, Colin; Plein, Sven; Greenwood, John P.

2015-01-01

Background A number of investigative strategies exist for the diagnosis of coronary heart disease (CHD). Despite the widespread availability of noninvasive imaging, invasive angiography is commonly used early in the diagnostic pathway. Consequently, approximately 60% of angiograms reveal no evidence of obstructive coronary disease. Reducing unnecessary angiography has potential financial savings and avoids exposing the patient to unnecessary risk. There are no large-scale comparative effectiveness trials of the different diagnostic strategies recommended in international guidelines and none that have evaluated the safety and efficacy of cardiovascular magnetic resonance. Trial Design CE-MARC 2 is a prospective, multicenter, 3-arm parallel group, randomized controlled trial of patients with suspected CHD (pretest likelihood 10%-90%) requiring further investigation. A total of 1,200 patients will be randomized on a 2:2:1 basis to receive 3.0-T cardiovascular magnetic resonance–guided care, single-photon emission computed tomography–guided care (according to American College of Cardiology/American Heart Association appropriate-use criteria), or National Institute for Health and Care Excellence guidelines–based management. The primary (efficacy) end point is the occurrence of unnecessary angiography as defined by a normal (>0.8) invasive fractional flow reserve. Safety of each strategy will be assessed by 3-year major adverse cardiovascular event rates. Cost-effectiveness and health-related quality-of-life measures will be performed. Conclusions The CE-MARC 2 trial will provide comparative efficacy and safety evidence for 3 different strategies of investigating patients with suspected CHD, with the intension of reducing unnecessary invasive angiography rates. Evaluation of these management strategies has the potential to improve patient care, health-related quality of life, and the cost-effectiveness of CHD investigation. PMID:25497243

The NEtherlands Cervical Kinematics (NECK) trial. Cost-effectiveness of anterior cervical discectomy with or without interbody fusion and arthroplasty in the treatment of cervical disc herniation; a double-blind randomised multicenter study.

PubMed

Arts, Mark P; Brand, Ronald; van den Akker, Elske; Koes, Bart W; Peul, Wilco C

2010-06-16

Patients with cervical radicular syndrome due to disc herniation refractory to conservative treatment are offered surgical treatment. Anterior cervical discectomy is the standard procedure, often in combination with interbody fusion. Accelerated adjacent disc degeneration is a known entity on the long term. Recently, cervical disc prostheses are developed to maintain motion and possibly reduce the incidence of adjacent disc degeneration. A comparative cost-effectiveness study focused on adjacent segment degeneration and functional outcome has not been performed yet. We present the design of the NECK trial, a randomised study on cost-effectiveness of anterior cervical discectomy with or without interbody fusion and arthroplasty in patients with cervical disc herniation. Patients (age 18-65 years) presenting with radicular signs due to single level cervical disc herniation lasting more than 8 weeks are included. Patients will be randomised into 3 groups: anterior discectomy only, anterior discectomy with interbody fusion, and anterior discectomy with disc prosthesis. The primary outcome measure is symptomatic adjacent disc degeneration at 2 and 5 years after surgery. Other outcome parameters will be the Neck Disability Index, perceived recovery, arm and neck pain, complications, re-operations, quality of life, job satisfaction, anxiety and depression assessment, medical consumption, absenteeism, and costs. The study is a randomised prospective multicenter trial, in which 3 surgical techniques are compared in a parallel group design. Patients and research nurses will be kept blinded of the allocated treatment for 2 years. The follow-up period is 5 years. Currently, anterior cervical discectomy with fusion is the golden standard in the surgical treatment of cervical disc herniation. Whether additional interbody fusion or disc prosthesis is necessary and cost-effective will be determined by this trial. Netherlands Trial Register NTR1289.

The MANDELA study: A multicenter, randomized, open-label, parallel group trial to refine the use of everolimus after heart transplantation.

PubMed

Deuse, Tobias; Bara, Christoph; Barten, Markus J; Hirt, Stephan W; Doesch, Andreas O; Knosalla, Christoph; Grinninger, Carola; Stypmann, Jörg; Garbade, Jens; Wimmer, Peter; May, Christoph; Porstner, Martina; Schulz, Uwe

2015-11-01

In recent years a series of trials has sought to define the optimal protocol for everolimus-based immunosuppression in heart transplantation, with the goal of minimizing exposure to calcineurin inhibitors (CNIs) and harnessing the non-immunosuppressive benefits of everolimus. Randomized studies have demonstrated that immunosuppressive potency can be maintained in heart transplant patients receiving everolimus despite marked CNI reduction, although very early CNI withdrawal may be inadvisable. A potential renal advantage has been shown for everolimus, but the optimal time for conversion and the adequate reduction in CNI exposure remain to be defined. Other reasons for use of everolimus include a substantial reduction in the risk of cytomegalovirus infection, and evidence for inhibition of cardiac allograft vasculopathy, a major cause of graft loss. The ongoing MANDELA study is a 12-month multicenter, randomized, open-label, parallel-group study in which efficacy, renal function and safety are compared in approximately 200 heart transplant patients. Patients receive CNI therapy, steroids and everolimus or mycophenolic acid during months 3 to 6 post-transplant, and are then randomized at month 6 post-transplant (i) to convert to CNI-free immunosuppression with everolimus and mycophenolic acid or (ii) to continue reduced-exposure CNI, with concomitant everolimus. Patients are then followed to month 18 post-transplant The rationale and expectations for the trial and its methodology are described herein. Copyright © 2015 Elsevier Inc. All rights reserved.

A Herbal Medicine, Gongjindan, in Subjects with Chronic Dizziness (GOODNESS Study): Study Protocol for a Prospective, Multicenter, Randomized, Double-Blind, Placebo-Controlled, Parallel-Group, Clinical Trial for Effectiveness, Safety, and Cost-Effectiveness

PubMed Central

Kim, Jinyoung; Cho, Jae-Heung

2017-01-01

This study protocol aims to explore the effectiveness, safety, and cost-effectiveness of a herbal medication, Gongjindan (GJD), in patients with chronic dizziness. This will be a prospective, multicenter, randomized, double-blind, placebo-controlled, parallel-group, clinical trial. Seventy-eight patients diagnosed with Meniere's disease, psychogenic dizziness, or dizziness of unknown cause will be randomized and allocated to either a GJD or a placebo group in a 1 : 1 ratio. Participants will be orally given 3.75 g GJD or placebo in pill form once a day for 56 days. The primary outcome measure will be the Dizziness Handicap Inventory score. Secondary outcome measures will be as follows: severity (mean vertigo scale and visual analogue scale) and frequency of dizziness, balance function (Berg Balance Scale), fatigue (Fatigue Severity Scale) and deficiency pattern/syndrome (qi blood yin yang-deficiency questionnaire) levels, and depression (Korean version of Beck's Depression Inventory) and anxiety (State-Trait Anxiety Inventory) levels. To assess safety, adverse events, including laboratory test results, will be monitored. Further, the incremental cost-effectiveness ratio will be calculated based on quality-adjusted life years (from the EuroQoL five dimensions' questionnaire) and medical expenses. Data will be statistically analyzed at a significance level of 0.05 (two-sided). This trial is registered with ClinicalTrials.gov NCT03219515, in July 2017. PMID:29387128

The efficacy and safety of Fufangdanshen tablets (Radix Salviae miltiorrhizae formula tablets) for mild to moderate vascular dementia: a study protocol for a randomized controlled trial.

PubMed

Tian, Jinzhou; Shi, Jing; Wei, Mingqing; Qin, Renan; Ni, Jingnian; Zhang, Xuekai; Li, Ting; Wang, Yongyan

2016-06-08

Vascular dementia (VaD) is the second most common subtype of dementia after Alzheimer's disease (AD). Currently, there are no medications approved for treating patients with VaD. Fufangdanshen (FFDS) tablets (Radix Salviae miltiorrhizae formula tablets) are a traditional Chinese medicine that has been reported to improve memory. However, the existing evidence for FFDS tablets in clinical practice derives from methodologically flawed studies. To further investigate the safety, tolerability, and efficacy of FFDS tables in the treatment of mild to moderate VaD, we designed and reported the methodology for a 24-week randomized, double-blind, parallel, multicenter study. This ongoing study is a double-blind, randomized, parallel placebo-controlled trial. A total of 240 patients with mild to moderate VaD will be enrolled. After a 2-week run-in period, the eligible patients will be randomized to receive either three FFDS or placebo tablets three times per day for 24 weeks, with a follow-up 12 weeks after the last treatment. The primary efficacy measurement will be the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) and the Clinician Interview-Based Impression of Change (CIBIC-plus). The secondary efficacy measurements will include the Mini Mental State Examination (MMSE) and activities of daily living (ADL). Adverse events will also be reported. This randomized trial will be the first rigorous study on the efficacy and safety of FFDS tablets for treating cognitive symptoms in patients with VaD using a rational design. ClinicalTrials.gov: NCT01761227 . Registered on 2 January 2013.

COPD online-rehabilitation versus conventional COPD rehabilitation - rationale and design for a multicenter randomized controlled trial study protocol (CORe trial).

PubMed

Hansen, Henrik; Bieler, Theresa; Beyer, Nina; Godtfredsen, Nina; Kallemose, Thomas; Frølich, Anne

2017-11-16

Rehabilitation of patients with chronic obstructive pulmonary disease (COPD) is a key treatment in COPD. However, despite the existing evidence and a strong recommendation from lung associations worldwide, 50% of patients with COPD decline to participate in COPD rehabilitation program and 30-50% drop-out before completion. The main reasons are severe symptoms, inflexible accessibility and necessity for transportation. Currently there are no well-established and evident rehabilitation alternatives. Supervised online screen rehabilitation could be a useful approach to increase accessibility and compliance. The aim of this multicenter RCT study is to compare the potential benefits of a 10-week online COPD rehabilitation program (CORe) with conventional outpatient COPD rehabilitation (CCRe). This study is a randomized assessor- and statistician blinded superiority multicenter trial with two parallel groups, employing 1:1 allocation to the intervention and the comparison group.On the basis of a sample size calculation, 134 patients with severe or very severe COPD and eligible to conventional hospital based outpatient COPD rehabilitation will be included and randomized from eight different hospitals. The CORe intervention group receives group supervised resistance- and endurance training and patient education, 60 min, three times/week for 10 weeks at home via online-screen. The CCRe comparison group receives group based supervised resistance- and endurance training and patient education, 90 min, two times/week for 10 weeks (two hospitals) or 12 weeks (six hospitals) in groups at the local hospital. The primary outcome is change in the 6-min walking distance after 10/12 weeks; the secondary outcomes are changes in 30 s sit-to-stand chair test, physical activity level, symptoms, anxiety and depression symptoms, disease specific and generic quality of life. Primary endpoint is 10/12 weeks from baseline, while secondary endpoints are 22, 36, 62 weeks from baseline assessments. The study will likely contribute to knowledge regarding COPD tele-rehabilitation and to which extent it is more feasible and thereby more efficient than conventional COPD rehabilitation in patients with severe and very severe COPD. Clinicaltrials.gov Identifier: NCT02667171 . Registration data: January 28th 2016.

Organizational structure and communication strategies of the bypass angioplasty revascularization investigation: a multicenter clinical trial.

PubMed

Naydeck, B L; Sutton-Tyrrell, K; Burek, K; Sopko, G S

1996-06-01

Efficient communication is a challenge for the many operating components of a multicenter randomized clinical trial. Traditional management theory states that communications generally flow along a path established by a hierarchical organizational structure. A multicenter clinical trial does not fit traditional organizational models well and requires modification of traditional communication techniques. While the scientific community typically views a clinical trial as one large and cohesive enterprise, at each site the trial may actually be conducted as a small project related to the medical specialty of the investigator. Therefore overall trial management must be accomplished through collaboration rather than through direct management. In the Bypass Angioplasty Revascularization Investigation (BARI), the BARI clinical coordinating center has designed and utilized several mechanisms that facilitate effective communication and administrative control of a multicenter clinical trial. These mechanisms provide a framework of communication techniques that accommodate the specific needs of a complex organization.

Challenges in the design and implementation of the Multicenter Uveitis Steroid Treatment (MUST) Trial--lessons for comparative effectiveness trials.

PubMed

Holbrook, Janet T; Kempen, John H; Prusakowski, Nancy A; Altaweel, Michael M; Jabs, Douglas A

2011-12-01

Randomized clinical trials (RCTs) are an important component of comparative effectiveness (CE) research because they are the optimal design for head-to-head comparisons of different treatment options. To describe decisions made in the design of the Multicenter Uveitis Steroid Treatment (MUST) Trial to ensure that the results would be widely generalizable. Review of design and implementation decisions and their rationale for the trial. The MUST Trial is a multicenter randomized controlled CE trial evaluating a novel local therapy (intraocular fluocinolone acetonide implant) versus the systemic therapy standard of care for noninfectious uveitis. Decisions made in protocol design in order to broaden enrollment included allowing patients with very poor vision and media opacity to enroll and including clinical sites outside the United States. The treatment protocol was designed to follow standard care. The primary outcome, visual acuity, is important to patients and can be evaluated in all eyes with uveitis. Other outcomes include patient-reported visual function, quality of life, and disease and treatment related complications. The trial population is too small for subgroup analyses that are of interest and the trial is being conducted at tertiary medical centers. CE trials require greater emphasis on generalizability than many RCTs but otherwise face similar challenges for design choices as any RCT. The increase in heterogeneity in patients and treatment required to ensure generalizability can be balanced with a rigorous approach to implementation, outcome assessment, and statistical design. This approach requires significant resources that may limit implementation in many RCTs, especially in clinical practice settings.

High-dose N-acetylcysteine in the prevention of COPD exacerbations: rationale and design of the PANTHEON Study.

PubMed

Zheng, Jin-Ping; Wen, Fu-Qiang; Bai, Chun-Xue; Wan, Huan-Ying; Kang, Jian; Chen, Ping; Yao, Wan-Zhen; Ma, Li-Jun; Xia, Qi-Kui; Gao, Yi; Zhong, Nan-Shan

2013-04-01

Chronic obstructive pulmonary disease (COPD) is characterized by persistent airflow limitation; from a pathophysiological point of view it involves many components, including mucus hypersecretion, oxidative stress and inflammation. N-acetylcysteine (NAC) is a mucolytic agent with antioxidant and anti-inflammatory properties. Long-term efficacy of NAC 600mg/d in COPD is controversial; a dose-effect relationship has been demonstrated, but at present it is not known whether a higher dose provides clinical benefits. The PANTHEON Study is a prospective, ICS stratified, randomized, double-blind, placebo-controlled, parallel-group, multi-center trial designed to assess the efficacy and safety of high-dose (1200 mg/daily) NAC treatment for one year in moderate-to-severe COPD patients. The primary endpoint is the annual exacerbation rate. Secondary endpoints include recurrent exacerbations hazard ratio, time to first exacerbation, as well as quality of life and pulmonary function. The hypothesis, design and methodology are described and baseline characteristics of recruited patients are presented. 1006 COPD patients (444 treated with maintenance ICS, 562 ICS naive, aged 66.27±8.76 yrs, average post-bronchodilator FEV1 48.95±11.80 of predicted) have been randomized at 34 hospitals in China. Final results of this study will provide objective data on the effects of high-dose (1200 mg/daily) long-term NAC treatment in the prevention of COPD exacerbations and other outcome variables.

Effectiveness of adjuvant radiotherapy in patients with oropharyngeal and floor of mouth squamous cell carcinoma and concomitant histological verification of singular ipsilateral cervical lymph node metastasis (pN1-state)--a prospective multicenter randomized controlled clinical trial using a comprehensive cohort design.

PubMed

Moergel, Maximilian; Jahn-Eimermacher, Antje; Krummenauer, Frank; Reichert, Torsten E; Wagner, Wilfried; Wendt, Thomas G; Werner, Jochen A; Al-Nawas, Bilal

2009-12-23

Modern radiotherapy plays an important role in therapy of advanced head and neck carcinomas. However, no clinical studies have been published addressing the effectiveness of postoperative radiotherapy in patients with small tumor (pT1, pT2) and concomitant ipsilateral metastasis of a single lymph node (pN1), which would provide a basis for a general treatment recommendation. The present study is a non-blinded, prospective, multi-center randomized controlled trial (RCT). As the primary clinical endpoint, overall-survival in patients receiving postoperative radiation therapy vs. patients without adjuvant therapy following curative intended surgery is compared. The aim of the study is to enroll 560 adult males and females for 1:1 randomization to one of the two treatment arms (irradiation/no irradiation). Since patients with small tumor (T1/T2) but singular lymph node metastasis are rare and the amount of patients consenting to randomization is not predictable in advance, all patients rejecting randomization will be treated as preferred and enrolled in a prospective observational study (comprehensive cohort design) after giving informed consent. This observational part of the trial will be performed with maximum consistency to the treatment and observation protocol of the RCT. Because the impact of patient preference for a certain treatment option is not calculable, parallel design of RCT and observational study may provide a maximum of evidence and efficacy for evaluation of treatment outcome. Secondary clinical endpoints are as follows: incidence and time to tumor relapse (locoregional relapse, lymph node involvement and distant metastatic spread), Quality of life as reported by EORTC (QLQ-C30 with H&N 35 module), and time from operation to orofacial rehabilitation. All tumors represent a homogeneous clinical state and therefore additional investigation of protein expression levels within resection specimen may serve for establishment of surrogate parameters of patient outcome. The inherent challenges of a rare clinical condition (pN1) and two substantially different therapy arms would limit the practicality of a classical randomized study. The concept of a Comprehensive Cohort Design combines the preference of a randomized study, with the option of careful data interpretation within an observational study. ClinicalTrials.gov: NCT00964977.

Ethinyl estradiol 20μg/drospirenone 3mg 24/4 oral contraceptive for the treatment of functional impairment in women with premenstrual dysphoric disorder.

PubMed

Marr, Joachim; Heinemann, Klaas; Kunz, Michael; Rapkin, Andrea

2011-05-01

To determine the effects of ethinyl estradiol (EE)/drospirenone in a 24/4 regimen (24days of active and 4days of inactive pills) on functional impairment (affecting work, partnership, and social activities) in women with premenstrual dysphoric disorder (PMDD). The present study was a secondary analysis of a double-blind, randomized, parallel-design multicenter trial. Women received EE 20μg/drospirenone 3mg (n=232) or placebo (n=218) and completed the Daily Record of Severity of Problems (DRSP) scale daily. The decrease in mean scores for all 3 DRSP functional impairment items (work, partnership, and social activities) from baseline to cycle 3 mirrored changes in the total DRSP symptom score; the greatest decreases were observed in cycle 1 with further small reductions through to cycle 3. The proportional mean decreases from baseline to cycle 1 for the 3 functional items ranged from 47% to 48%. For all 3 functional items, the mean reductions from baseline to cycle 1 (but not from cycle 1 to cycles 2 and 3) were significantly greater with EE/drospirenone than with placebo (P<0.05). Ethinyl estradiol 20μg/drospirenone 3mg in a 24/4 regimen significantly improved functional impairment in women with PMDD. Symptoms improved in parallel. Copyright © 2011 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Advancing the evidence base in cancer: psychosocial multicenter trials

PubMed Central

2012-01-01

Background The diagnosis and treatment of cancer is associated with significant distress and psychosocial morbidity. Although psychosocial interventions have been developed in an attempt to improve psychosocial outcomes in cancer patients and survivors, there is continued debate about whether there is adequate high-level evidence to establish the effectiveness of these interventions. The evidence base is limited as a result of numerous challenges faced by those attempting to conduct psychosocial intervention trials within the health system. Barriers include insufficient participant recruitment, difficulty generalizing from single-trial studies, difficulty in building and managing research teams with multidisciplinary expertise, lack of research design expertise and a lack of incentives for researchers conducting intervention research. To strengthen the evidence base, more intervention studies employing methodologically rigorous research designs are necessary. Methods In order to advance the evidence base of interventions designed to improve psychosocial outcomes for cancer patients and survivors, we propose the formation of a collaborative trials group that conducts multicenter trials to test the effectiveness of such interventions. Results Establishment of such a group would improve the quality of the evidence base in psychosocial research in cancer patients, by increasing support for conducting intervention research and providing intervention research training opportunities. A multidisciplinary collaborative group conducting multicenter trials would have the capacity to overcome many of the barriers that currently exist. Conclusions A stronger evidence base is necessary to identify effective psychosocial interventions for cancer patients. The proposed formation of a psycho-oncology collaborative trials group that conducts multicenter trials to test the effectiveness of psychosocial interventions would assist in achieving this outcome. PMID:22992443

Two Double-Blind, Multicenter, Randomized, Placebo-Controlled, Single-Dose Studies of Sumatriptan/Naproxen Sodium in the Acute Treatment of Migraine: Function, Productivity, and Satisfaction Outcomes

PubMed Central

Landy, Stephen; DeRossett, Sarah E.; Rapoport, Alan; Rothrock, John; Ames, Michael H.; McDonald, Susan A.; Burch, Steven P.

2007-01-01

Objective To describe return to normal function, productivity, and satisfaction of patients with moderate or severe migraine attacks treated with combined sumatriptan/naproxen sodium, sumatriptan alone, naproxen sodium alone, or placebo. Patients, design, and setting Patients in 2 identical, US, phase 3, randomized, double-blind, parallel-group, placebo-controlled, single-dose, multicenter studies treated a single moderate or severe migraine attack with sumatriptan/naproxen sodium (85 mg sumatriptan formulated with RT Technology and 500 mg naproxen sodium in a single-tablet formulation), sumatriptan, naproxen sodium, or placebo. Main outcome measures Ability to function (not impaired, mildly impaired, severely impaired, or required bed rest) was collected in diary cards completed immediately prior to treatment, every 30 minutes for the first 2 hours, and hourly from 2 to 24 hours while awake. Patients completed the Productivity Assessment Questionnaire (PAQ) 24 hours after study drug administration. The Patient Perception of Migraine Questionnaire (PPMQ) was administered at screening and 24 hours post treatment to capture patient satisfaction. Results Compared with the other groups, the sumatriptan/naproxen sodium group reported significantly higher levels of normal or mildly impaired functioning as early as 2 and 4 hours after dosing. They also demonstrated greater reductions in workplace productivity loss compared with placebo in both studies, and were consistently more satisfied with their treatment compared with patients in other treatment groups and compared with their usual medications. Conclusions Treatment with sumatriptan/naproxen sodium allowed significantly more subjects to return to normal or mildly impaired functioning more quickly, and sumatriptan/naproxen sodium patients were significantly more satisfied with their treatment compared with other treatment groups. Overall productivity loss was significantly reduced following use of sumatriptan/naproxen sodium. PMID:17955107

Rationale and design of the multicenter randomized trial investigating the effects of levosimendan pretreatment in patients with low ejection fraction (≤40 %) undergoing CABG with cardiopulmonary bypass (LICORN study).

PubMed

Caruba, Thibaut; Hourton, Delphine; Sabatier, Brigitte; Rousseau, Dominique; Tibi, Annick; Hoffart-Jourdain, Cécile; Souag, Akim; Freitas, Nelly; Yjjou, Mounia; Almeida, Carla; Gomes, Nathalie; Aucouturier, Pascaline; Djadi-Prat, Juliette; Menasché, Philippe; Chatellier, Gilles; Cholley, Bernard

2016-08-05

Patients with a left ventricular ejection fraction (LVEF) of less than 40 % are at high risk of developing postoperative low cardiac output syndrome (LCOS). Despite actual treatments (inotropic agents and/or mechanical assist devices), the mortality rate of such patients remains very high (13 to 24 %). The LICORN trial aims at assessing the efficacy of a preoperative infusion of levosimendan in reducing postoperative LCOS in patients with poor LVEF undergoing coronary artery bypass grafting (CABG). LICORN study is a multicenter, randomized double-blind, placebo-controlled trial in parallel groups. 340 patients with LVEF ≤40 %, undergoing CABG will be recruited from 13 French hospitals. The study drug will be started after anaesthesia induction and infused over 24 h (0.1 μg/kg/min). The primary outcome (postoperative LCOS) is evaluated using a composite criterion composed of: 1) need for inotropic agents beyond 24 h following discontinuation of the study drug; 2) need for post-operative mechanical assist devices or failure to wean from these techniques when inserted pre-operatively; 3) need for renal replacement therapy. Secondary outcomes include: 1) mortality at Day 28 and Day 180; 2) each item of the composite criterion of the primary outcome; 3) the number of "ventilator-free" days and "out of intensive care unit" days at Day 28. The usefulness of levosimendan in the perioperative period has not yet been documented with a high level of evidence. The LICORN study is the first randomized controlled trial evaluating the clinical value of preoperative levosimendan in high risk cardiac surgical patients undergoing CABG. NCT02184819 (ClinicalTrials.gov).

Internet-delivered cognitive-behavioral treatment for adolescents with chronic pain and their parents: a randomized controlled multicenter trial

PubMed Central

Palermo, Tonya M.; Law, Emily F.; Fales, Jessica; Bromberg, Maggie H.; Jessen-Fiddick, Tricia; Tai, Gabrielle

2016-01-01

Internet-delivered interventions are emerging as a strategy to address barriers to care for individuals with chronic pain. This is the first large multicenter randomized controlled trial of Internet-delivered cognitive-behavioral therapy (CBT) for pediatric chronic pain. Participants included were 273 adolescents (205 females and 68 males), aged 11 to 17 years with mixed chronic pain conditions and their parents, who were randomly assigned in a parallel-group design to Internet-delivered CBT (n = 138) or Internet-delivered Education (n = 135). Assessments were completed before treatment, immediately after treatment, and at 6-month follow-up. All data collection and procedures took place online. The primary analysis used linear growth models. Results demonstrated significantly greater reduction on the primary outcome of activity limitations from baseline to 6-month follow-up for Internet CBT compared with Internet education (b = −1.13, P = 0.03). On secondary outcomes, significant beneficial effects of Internet CBT were found on sleep quality (b = 0.14, P = 0.04), on reducing parent miscarried helping (b = −2.66, P = 0.007) and protective behaviors (b = −0.19, P = 0.001), and on treatment satisfaction (P values < 0.05). On exploratory outcomes, benefits of Internet CBT were found for parent-perceived impact (ie, reductions in depression, anxiety, self-blame about their adolescent’s pain, and improvement in parent behavioral responses to pain). In conclusion, our Internet-delivered CBT intervention produced a number of beneficial effects on adolescent and parent outcomes, and could ultimately lead to wide dissemination of evidence-based psychological pain treatment for youth and their families. PMID:26335910

Comparative analytical evaluation of the respiratory TaqMan Array Card with real-time PCR and commercial multi-pathogen assays.

PubMed

Harvey, John J; Chester, Stephanie; Burke, Stephen A; Ansbro, Marisela; Aden, Tricia; Gose, Remedios; Sciulli, Rebecca; Bai, Jing; DesJardin, Lucy; Benfer, Jeffrey L; Hall, Joshua; Smole, Sandra; Doan, Kimberly; Popowich, Michael D; St George, Kirsten; Quinlan, Tammy; Halse, Tanya A; Li, Zhen; Pérez-Osorio, Ailyn C; Glover, William A; Russell, Denny; Reisdorf, Erik; Whyte, Thomas; Whitaker, Brett; Hatcher, Cynthia; Srinivasan, Velusamy; Tatti, Kathleen; Tondella, Maria Lucia; Wang, Xin; Winchell, Jonas M; Mayer, Leonard W; Jernigan, Daniel; Mawle, Alison C

2016-02-01

In this study, a multicenter evaluation of the Life Technologies TaqMan(®) Array Card (TAC) with 21 custom viral and bacterial respiratory assays was performed on the Applied Biosystems ViiA™ 7 Real-Time PCR System. The goal of the study was to demonstrate the analytical performance of this platform when compared to identical individual pathogen specific laboratory developed tests (LDTs) designed at the Centers for Disease Control and Prevention (CDC), equivalent LDTs provided by state public health laboratories, or to three different commercial multi-respiratory panels. CDC and Association of Public Health Laboratories (APHL) LDTs had similar analytical sensitivities for viral pathogens, while several of the bacterial pathogen APHL LDTs demonstrated sensitivities one log higher than the corresponding CDC LDT. When compared to CDC LDTs, TAC assays were generally one to two logs less sensitive depending on the site performing the analysis. Finally, TAC assays were generally more sensitive than their counterparts in three different commercial multi-respiratory panels. TAC technology allows users to spot customized assays and design TAC layout, simplify assay setup, conserve specimen, dramatically reduce contamination potential, and as demonstrated in this study, analyze multiple samples in parallel with good reproducibility between instruments and operators. Copyright © 2015 Elsevier B.V. All rights reserved.

Twelve-week, multicenter, placebo-controlled, randomized, double-blind, parallel-group, comparative phase II/III study of benzoyl peroxide gel in patients with acne vulgaris: A secondary publication.

PubMed

Kawashima, Makoto; Sato, Shinichi; Furukawa, Fukumi; Matsunaga, Kayoko; Akamatsu, Hirohiko; Igarashi, Atsuyuki; Tsunemi, Yuichiro; Hayashi, Nobukazu; Yamamoto, Yuki; Nagare, Toshitaka; Katsuramaki, Tsuneo

2017-07-01

A placebo-controlled, randomized, double-blind, parallel-group, comparative, multicenter study was conducted to investigate the efficacy and safety of benzoyl peroxide (BPO) gel, administrated once daily for 12 weeks to Japanese patients with acne vulgaris. Efficacy was evaluated by counting all inflammatory and non-inflammatory lesions. Safety was evaluated based on adverse events, local skin tolerability scores and laboratory test values. All 609 subjects were randomly assigned to receive the study products (2.5% and 5% BPO and placebo), and 607 subjects were included in the full analysis set, 544 in the per protocol set and 609 in the safety analyses. The median rates of reduction from baseline to the last evaluation of the inflammatory lesion counts, the primary end-point, in the 2.5% and 5% BPO groups were 72.7% and 75.0%, respectively, and were significantly higher than that in the placebo group (41.7%). No deaths or other serious adverse events were observed. The incidences of adverse events in the 2.5% and 5% BPO groups were 56.4% and 58.8%, respectively; a higher incidence than in the placebo group, but there was no obvious difference between the 2.5% and 5% BPO groups. All adverse events were mild or moderate in severity. Most adverse events did not lead to study product discontinuation. The results suggested that both 2.5% and 5% BPO are useful for the treatment of acne vulgaris. © 2017 The Authors. The Journal of Dermatology published by John Wiley & Sons Australia, Ltd.

An Open Label, Randomized, Comparative, Parallel Group, Multicenter, Prospective, Interventional, Clinical Study to Evaluate Efficacy and Safety of "AHPL/AYTOP/0113" in Comparison with "Framycetin Sulphate Cream" in Acute Wounds.

PubMed

Nipanikar, Sanjay U; Gajare, Kamalakar V; Vaidya, Vidyadhar G; Kamthe, Amol B; Upasani, Sachin A; Kumbhar, Vidyadhar S

2017-01-01

The main objective of the present study was to assess efficacy and safety of AHPL/AYTOP/0113 cream, a polyherbal formulation in comparison with Framycetin sulphate cream in acute wounds. It was an open label, randomized, comparative, parallel group and multi-center clinical study. Total 47 subjects were randomly assigned to Group-A (AHPL/AYTOP/0113 cream) and 42 subjects were randomly assigned to Group-B (Framycetin sulphate cream). All the subjects were advised to apply study drug, thrice daily for 21 days or up to complete wound healing (whichever was earlier). All the subjects were called for follow up on days 2, 4, 7, 10, 14, 17 and 21 or up to the day of complete wound healing. Data describing quantitative measures are expressed as mean ± SD. Comparison of variables representing categorical data was performed using Chi-square test. Group-A subjects took significantly less ( P < 0.05) i.e., (mean) 7.77 days than (mean) 9.87 days of Group-B subjects for wound healing. At the end of the study, statistically significant better ( P < 0.05) results were observed in Group-A than Group-B in mean wound surface area, wound healing parameters and pain associated with wound. Excellent overall efficacy and tolerability was observed in subjects of both the groups. No adverse event or adverse drug reaction was noted in any subject of both the groups. AHPL/AYTOP/0113 cream proved to be superior to Framycetin sulphate cream in healing of acute wounds.

A Phase III, Multicenter, Parallel-Design Clinical Trial to Compare the Efficacy and Safety of 5% Minoxidil Foam Versus Vehicle in Women With Female Pattern Hair Loss.

PubMed

Bergfeld, Wilma; Washenik, Ken; Callender, Valerie; Zhang, Paul; Quiza, Carlos; Doshi, Uday; Blume-Peytavi, Ulrike

2016-07-01

BACKGROUND Female pattern hair loss (FPHL) is a common hair disorder that affects millions of women. A new 5% minoxidil topical foam (MTF) formulation, which does not contain propylene glycol, has been developed.
To compare the efficacy and safety of once-daily 5% MTF with vehicle foam for the treatment of FPHL.
This was a Phase III, randomized, double-blind, vehicle-controlled, parallel-group, international multicenter trial (17 sites) in women aged at least 18 years with FPHL (grade D3 to D6 on the Savin Density Scale), treated once daily with 5% MTF or vehicle foam for 24 weeks. The co-primary efficacy endpoints were the change from baseline at week 24 in target area hair count (TAHC) and subject assessment of scalp coverage. Also evaluated were TAHC at week 12, expert panel review of hair regrowth at week 24, and change from baseline in total unit area density (TUAD, sum of hair diameters/cm²) at weeks 12 and 24.
A total of 404 women were enrolled. At 12 and 24 weeks, 5% MTF treatment resulted in regrowth of 10.9 hairs/cm² and 9.1 hairs/cm² more than vehicle foam, respectively (both P<.0001). Improved scalp coverage at week 24 was observed by both subject self-assessment (0.69-point improvement over vehicle foam; P<.0001) and expert panel review (0.36-point improvement over the vehicle foam; P<.0001). TUAD increased by 658 μm/cm² and 644 μm/cm² more with 5% MTF than with vehicle foam at weeks 12 and 24, respectively (both P<.0001). MTF was well tolerated. A low incidence of scalp irritation and facial hypertrichosis was observed, with no clinically significant differences between groups.
Five percent MTF once daily for 24 weeks was well tolerated and promoted hair regrowth in women with FPHL, resulting in improved scalp coverage and increased hair density compared with vehicle foam. ClinicalTrials.gov identifier: nCT01226459

J Drugs Dermatol. 2016;15(7):874-881.

Experimental determination of pCo perturbation factors for plane-parallel chambers

NASA Astrophysics Data System (ADS)

Kapsch, R. P.; Bruggmoser, G.; Christ, G.; Dohm, O. S.; Hartmann, G. H.; Schüle, E.

2007-12-01

For plane-parallel chambers used in electron dosimetry, modern dosimetry protocols recommend a cross-calibration against a calibrated cylindrical chamber. The rationale for this is the unacceptably large (up to 3-4%) chamber-to-chamber variations of the perturbation factors (pwall)Co, which have been reported for plane-parallel chambers of a given type. In some recent publications, it was shown that this is no longer the case for modern plane-parallel chambers. The aims of the present study are to obtain reliable information about the variation of the perturbation factors for modern types of plane-parallel chambers, and—if this variation is found to be acceptably small—to determine type-specific mean values for these perturbation factors which can be used for absorbed dose measurements in electron beams using plane-parallel chambers. In an extensive multi-center study, the individual perturbation factors pCo (which are usually assumed to be equal to (pwall)Co) for a total of 35 plane-parallel chambers of the Roos type, 15 chambers of the Markus type and 12 chambers of the Advanced Markus type were determined. From a total of 188 cross-calibration measurements, variations of the pCo values for different chambers of the same type of at most 1.0%, 0.9% and 0.6% were found for the chambers of the Roos, Markus and Advanced Markus types, respectively. The mean pCo values obtained from all measurements are \\bar{p}^Roos_Co = 1.0198, \\bar{p}^Markus_Co = 1.0175 and \\bar{p}^Advanced_Co = 1.0155 ; the relative experimental standard deviation of the individual pCo values is less than 0.24% for all chamber types; the relative standard uncertainty of the mean pCo values is 1.1%.

Performance Evaluation of Parallel Branch and Bound Search with the Intel iPSC (Intel Personal SuperComputer) Hypercube Computer.

DTIC Science & Technology

1986-12-01

17 III. Analysis of Parallel Design ................................................ 18 Parallel Abstract Data ...Types ........................................... 18 Abstract Data Type .................................................. 19 Parallel ADT...22 Data -Structure Design ........................................... 23 Object-Oriented Design

Effectiveness of adjuvant radiotherapy in patients with oropharyngeal and floor of mouth squamous cell carcinoma and concomitant histological verification of singular ipsilateral cervical lymph node metastasis (pN1-state) - A prospective multicenter randomized controlled clinical trial using a comprehensive cohort design

PubMed Central

2009-01-01

Background Modern radiotherapy plays an important role in therapy of advanced head and neck carcinomas. However, no clinical studies have been published addressing the effectiveness of postoperative radiotherapy in patients with small tumor (pT1, pT2) and concomitant ipsilateral metastasis of a single lymph node (pN1), which would provide a basis for a general treatment recommendation. Methods/Design The present study is a non-blinded, prospective, multi-center randomized controlled trial (RCT). As the primary clinical endpoint, overall-survival in patients receiving postoperative radiation therapy vs. patients without adjuvant therapy following curative intended surgery is compared. The aim of the study is to enroll 560 adult males and females for 1:1 randomization to one of the two treatment arms (irradiation/no irradiation). Since patients with small tumor (T1/T2) but singular lymph node metastasis are rare and the amount of patients consenting to randomization is not predictable in advance, all patients rejecting randomization will be treated as preferred and enrolled in a prospective observational study (comprehensive cohort design) after giving informed consent. This observational part of the trial will be performed with maximum consistency to the treatment and observation protocol of the RCT. Because the impact of patient preference for a certain treatment option is not calculable, parallel design of RCT and observational study may provide a maximum of evidence and efficacy for evaluation of treatment outcome. Secondary clinical endpoints are as follows: incidence and time to tumor relapse (locoregional relapse, lymph node involvement and distant metastatic spread), Quality of life as reported by EORTC (QLQ-C30 with H&N 35 module), and time from operation to orofacial rehabilitation. All tumors represent a homogeneous clinical state and therefore additional investigation of protein expression levels within resection specimen may serve for establishment of surrogate parameters of patient outcome. Conclusion The inherent challenges of a rare clinical condition (pN1) and two substantially different therapy arms would limit the practicality of a classical randomized study. The concept of a Comprehensive Cohort Design combines the preference of a randomized study, with the option of careful data interpretation within an observational study. Trial registration ClinicalTrials.gov: NCT00964977 PMID:20028566

Hyperbaric oxygen for neurologic indications--action plan for multicenter trials in: stroke, traumatic brain injury, radiation encephalopathy & status migrainosus.

PubMed

Helms, A; Evans, A W; Chu, J; Sahgal, A; Ostrowski, R; Sosiak, T; Wolf, G; Gillett, J; Whelan, H

2011-01-01

The 2008 Toronto Hyperbaric Medicine Symposium was convened to discuss research into neurologic indications for hyperbaric oxygen therapy (HBO2T). Four topics were particularly addressed: acute ischemic stroke; acute traumatic brain injury; brain radiation necrosis; and status migrainosus. Four multicenter trials were designed and proposed to evaluate the efficacy of HBO2T for these indications and are presented here in addition to brief reviews of the rationale behind each.

Design of the evolution of management strategies of heart failure patients with implantable defibrillators (EVOLVO) study to assess the ability of remote monitoring to treat and triage patients more effectively

PubMed Central

Marzegalli, Maurizio; Landolina, Maurizio; Lunati, Maurizio; Perego, Giovanni B; Pappone, Alessia; Guenzati, Giuseppe; Campana, Carlo; Frigerio, Maria; Parati, Gianfranco; Curnis, Antonio; Colangelo, Irene; Valsecchi, Sergio

2009-01-01

Background Heart failure patients with implantable defibrillators (ICD) frequently visit the clinic for routine device monitoring. Moreover, in the case of clinical events, such as ICD shocks or alert notifications for changes in cardiac status or safety issues, they often visit the emergency department or the clinic for an unscheduled visit. These planned and unplanned visits place a great burden on healthcare providers. Internet-based remote device interrogation systems, which give physicians remote access to patients' data, are being proposed in order to reduce routine and interim visits and to detect and notify alert conditions earlier. Methods The EVOLVO study is a prospective, randomized, parallel, unblinded, multicenter clinical trial designed to compare remote ICD management with the current standard of care, in order to assess its ability to treat and triage patients more effectively. Two-hundred patients implanted with wireless-transmission-enabled ICD will be enrolled and randomized to receive either the Medtronic CareLink® monitor for remote transmission or the conventional method of in-person evaluations. The purpose of this manuscript is to describe the design of the trial. The results, which are to be presented separately, will characterize healthcare utilizations as a result of ICD follow-up by means of remote monitoring instead of conventional in-person evaluations. Trial registration ClinicalTrials.gov: NCT00873899 PMID:19538734

Rationale, Design, and Methods of the Preschool ADHD Treatment Study (PATS)

ERIC Educational Resources Information Center

Kollins, Scott; Greenhill, Laurence; Swanson, James; Wigal, Sharon; Abikoff, Howard; McCracken, James; Riddle, Mark; McGough, James; Vitiello, Benedetto; Wigal, Tim; Skrobala, Anne; Posner, Kelly; Ghuman, Jaswinder; Davies, Mark; Cunningham, Charles; Bauzo, Audrey

2006-01-01

Objective: To describe the rationale and design of the Preschool ADHD Treatment Study (PATS). Method: PATS was a National Institutes of Mental Health-funded, multicenter, randomized, efficacy trial designed to evaluate the short-term (5 weeks) efficacy and long-term (40 weeks) safety of methylphenidate (MPH) in preschoolers with…

The Diabeo software enabling individualized insulin dose adjustments combined with telemedicine support improves HbA1c in poorly controlled type 1 diabetic patients: a 6-month, randomized, open-label, parallel-group, multicenter trial (TeleDiab 1 Study).

PubMed

Charpentier, Guillaume; Benhamou, Pierre-Yves; Dardari, Dured; Clergeot, Annie; Franc, Sylvia; Schaepelynck-Belicar, Pauline; Catargi, Bogdan; Melki, Vincent; Chaillous, Lucy; Farret, Anne; Bosson, Jean-Luc; Penfornis, Alfred

2011-03-01

To demonstrate that Diabeo software enabling individualized insulin dose adjustments combined with telemedicine support significantly improves HbA(1c) in poorly controlled type 1 diabetic patients. In a six-month open-label parallel-group, multicenter study, adult patients (n = 180) with type 1 diabetes (>1 year), on a basal-bolus insulin regimen (>6 months), with HbA(1c) ≥ 8%, were randomized to usual quarterly follow-up (G1), home use of a smartphone recommending insulin doses with quarterly visits (G2), or use of the smartphone with short teleconsultations every 2 weeks but no visit until point end (G3). Six-month mean HbA(1c) in G3 (8.41 ± 1.04%) was lower than in G1 (9.10 ± 1.16%; P = 0.0019). G2 displayed intermediate results (8.63 ± 1.07%). The Diabeo system gave a 0.91% (0.60; 1.21) improvement in HbA(1c) over controls and a 0.67% (0.35; 0.99) reduction when used without teleconsultation. There was no difference in the frequency of hypoglycemic episodes or in medical time spent for hospital or telephone consultations. However, patients in G1 and G2 spent nearly 5 h more than G3 patients attending hospital visits. The Diabeo system gives a substantial improvement to metabolic control in chronic, poorly controlled type 1 diabetic patients without requiring more medical time and at a lower overall cost for the patient than usual care.

[Effect of Xinling Wan in treatment of stable angina pectoris: a randomized, double-blinded, placebo parallel-controlled, multicenter trial].

PubMed

Gao, Jian-Wei; Gao, Xue-Min; Zou, Ting; Zhao, Tian-Meng; Wang, Dong-Hua; Wu, Zong-Gui; Ren, Chang-Jie; Wang, Xing; Geng, Nai-Zhi; Zhao, Ming-Jun; Liang, Qiu-Ming; Feng, Xing; Yang, Bai-Song; Shi, Jun-Ling; Hua, Qi

2018-03-01

To evaluate the effectiveness and safety of Xinling Wan on patients with stable angina pectoris, a randomized, double-blinded, placebo parallel-controlled, multicenter clinical trial was conducted. A total of 232 subjects were enrolled and randomly divided into experiment group and placebo group. The experiment group was treated with Xinling Wan (two pills each time, three times daily) for 4 weeks, and the placebo group was treated with placebo. The effectiveness evaluation showed that Xinling Wan could significantly increase the total duration of treadmill exercise among patients with stable angina pectoris. FAS analysis showed that the difference value of the total exercise duration was between experiment group (72.11±139.32) s and placebo group (31.25±108.32) s. Xinling Wan could remarkably increase the total effective rate of angina pectoris symptom score, and the analysis showed that the total effective rate was 78.95% in experiment group and 42.61% in placebo group. The reduction of nitroglycerin dose was (2.45±2.41) tablets in experiment group and (0.50±2.24) tablets in placebo group on the basis of FAS analysis. The decrease of symptom integral was (4.68±3.49) in experiment group and (3.19±3.31) in placebo group based on FAS analysis. Besides, Xinling Wan could decrease the weekly attack time and the duration of angina pectoris. PPS analysis results were similar to those of FAS analysis. In conclusion, Xinling Wan has an obvious therapeutic effect in treating stable angina pectoris, with a good safety and a low incidence of adverse event and adverse reaction in experiment group. Copyright© by the Chinese Pharmaceutical Association.

HPCC Methodologies for Structural Design and Analysis on Parallel and Distributed Computing Platforms

NASA Technical Reports Server (NTRS)

Farhat, Charbel

1998-01-01

In this grant, we have proposed a three-year research effort focused on developing High Performance Computation and Communication (HPCC) methodologies for structural analysis on parallel processors and clusters of workstations, with emphasis on reducing the structural design cycle time. Besides consolidating and further improving the FETI solver technology to address plate and shell structures, we have proposed to tackle the following design related issues: (a) parallel coupling and assembly of independently designed and analyzed three-dimensional substructures with non-matching interfaces, (b) fast and smart parallel re-analysis of a given structure after it has undergone design modifications, (c) parallel evaluation of sensitivity operators (derivatives) for design optimization, and (d) fast parallel analysis of mildly nonlinear structures. While our proposal was accepted, support was provided only for one year.

Minimum envelope roughness pulse design for reduced amplifier distortion in parallel excitation.

PubMed

Grissom, William A; Kerr, Adam B; Stang, Pascal; Scott, Greig C; Pauly, John M

2010-11-01

Parallel excitation uses multiple transmit channels and coils, each driven by independent waveforms, to afford the pulse designer an additional spatial encoding mechanism that complements gradient encoding. In contrast to parallel reception, parallel excitation requires individual power amplifiers for each transmit channel, which can be cost prohibitive. Several groups have explored the use of low-cost power amplifiers for parallel excitation; however, such amplifiers commonly exhibit nonlinear memory effects that distort radio frequency pulses. This is especially true for pulses with rapidly varying envelopes, which are common in parallel excitation. To overcome this problem, we introduce a technique for parallel excitation pulse design that yields pulses with smoother envelopes. We demonstrate experimentally that pulses designed with the new technique suffer less amplifier distortion than unregularized pulses and pulses designed with conventional regularization.

Rationale and design of a randomized, double-blind, parallel-group study of terutroban 30 mg/day versus aspirin 100 mg/day in stroke patients: the prevention of cerebrovascular and cardiovascular events of ischemic origin with terutroban in patients with a history of ischemic stroke or transient ischemic attack (PERFORM) study.

PubMed

Bousser, M G; Amarenco, P; Chamorro, A; Fisher, M; Ford, I; Fox, K; Hennerici, M G; Mattle, H P; Rothwell, P M

2009-01-01

Ischemic stroke is the leading cause of mortality worldwide and a major contributor to neurological disability and dementia. Terutroban is a specific TP receptor antagonist with antithrombotic, antivasoconstrictive, and antiatherosclerotic properties, which may be of interest for the secondary prevention of ischemic stroke. This article describes the rationale and design of the Prevention of cerebrovascular and cardiovascular Events of ischemic origin with teRutroban in patients with a history oF ischemic strOke or tRansient ischeMic Attack (PERFORM) Study, which aims to demonstrate the superiority of the efficacy of terutroban versus aspirin in secondary prevention of cerebrovascular and cardiovascular events. The PERFORM Study is a multicenter, randomized, double-blind, parallel-group study being carried out in 802 centers in 46 countries. The study population includes patients aged > or =55 years, having suffered an ischemic stroke (< or =3 months) or a transient ischemic attack (< or =8 days). Participants are randomly allocated to terutroban (30 mg/day) or aspirin (100 mg/day). The primary efficacy endpoint is a composite of ischemic stroke (fatal or nonfatal), myocardial infarction (fatal or nonfatal), or other vascular death (excluding hemorrhagic death of any origin). Safety is being evaluated by assessing hemorrhagic events. Follow-up is expected to last for 2-4 years. Assuming a relative risk reduction of 13%, the expected number of primary events is 2,340. To obtain statistical power of 90%, this requires inclusion of at least 18,000 patients in this event-driven trial. The first patient was randomized in February 2006. The PERFORM Study will explore the benefits and safety of terutroban in secondary cardiovascular prevention after a cerebral ischemic event. Copyright 2009 S. Karger AG, Basel.

Cerebral Oximetry Monitoring to Maintain Normal Cerebral Oxygen Saturation during High-risk Cardiac Surgery: A Randomized Controlled Feasibility Trial.

PubMed

Deschamps, Alain; Hall, Richard; Grocott, Hilary; Mazer, C David; Choi, Peter T; Turgeon, Alexis F; de Medicis, Etienne; Bussières, Jean S; Hudson, Christopher; Syed, Summer; Seal, Doug; Herd, Stuart; Lambert, Jean; Denault, André; Deschamps, Alain; Mutch, Alan; Turgeon, Alexis; Denault, Andre; Todd, Andrea; Jerath, Angela; Fayad, Ashraf; Finnegan, Barry; Kent, Blaine; Kennedy, Brent; Cuthbertson, Brian H; Kavanagh, Brian; Warriner, Brian; MacAdams, Charles; Lehmann, Christian; Fudorow, Christine; Hudson, Christopher; McCartney, Colin; McIsaac, Dan; Dubois, Daniel; Campbell, David; Mazer, David; Neilpovitz, David; Rosen, David; Cheng, Davy; Drapeau, Dennis; Dillane, Derek; Tran, Diem; Mckeen, Dolores; Wijeysundera, Duminda; Jacobsohn, Eric; Couture, Etienne; de Medicis, Etienne; Alam, Fahad; Abdallah, Faraj; Ralley, Fiona E; Chung, Frances; Lellouche, Francois; Dobson, Gary; Germain, Genevieve; Djaiani, George; Gilron, Ian; Hare, Gregory; Bryson, Gregory; Clarke, Hance; McDonald, Heather; Roman-Smith, Helen; Grocott, Hilary; Yang, Homer; Douketis, James; Paul, James; Beaubien, Jean; Bussières, Jean; Pridham, Jeremy; Armstrong, J N; Parlow, Joel; Murkin, John; Gamble, Jonathan; Duttchen, Kaylene; Karkouti, Keyvan; Turner, Kim; Baghirzada, Leyla; Szabo, Linda; Lalu, Manoj; Wasowicz, Marcin; Bautista, Michael; Jacka, Michael; Murphy, Michael; Schmidt, Michael; Verret, Michaël; Perrault, Michel-Antoine; Beaudet, Nicolas; Buckley, Norman; Choi, Peter; MacDougall, Peter; Jones, Philip; Drolet, Pierre; Beaulieu, Pierre; Taneja, Ravi; Martin, Rene; Hall, Richard; George, Ronald; Chun, Rosa; McMullen, Sarah; Beattie, Scott; Sampson, Sonia; Choi, Stephen; Kowalski, Stephen; McCluskey, Stuart; Syed, Summer; Boet, Sylvain; Ramsay, Tim; Saha, Tarit; Mutter, Thomas; Chowdhury, Tumul; Uppal, Vishal; Mckay, William

2016-04-01

Cerebral oxygen desaturation during cardiac surgery has been associated with adverse perioperative outcomes. Before a large multicenter randomized controlled trial (RCT) on the impact of preventing desaturations on perioperative outcomes, the authors undertook a randomized prospective, parallel-arm, multicenter feasibility RCT to determine whether an intervention algorithm could prevent desaturations. Eight Canadian sites randomized 201 patients between April 2012 and October 2013. The primary outcome was the success rate of reversing cerebral desaturations below 10% relative to baseline in the intervention group. Anesthesiologists were blinded to the cerebral saturation values in the control group. Intensive care unit personnel were blinded to cerebral saturation values for both groups. Secondary outcomes included the area under the curve of cerebral desaturation load, enrolment rates, and a 30-day follow-up for adverse events. Cerebral desaturations occurred in 71 (70%) of the 102 intervention group patients and 56 (57%) of the 99 control group patients (P = 0.04). Reversal was successful in 69 (97%) of the intervention group patients. The mean cerebral desaturation load (SD) in the operating room was smaller for intervention group patients compared with control group patients (104 [217] %.min vs. 398 [869] %.min, mean difference, -294; 95% CI, -562 to -26; P = 0.03). This was also true in the intensive care unit (P = 0.02). There were no differences in adverse events between the groups. Study sites were successful in reversal of desaturation, patient recruitment, randomization, and follow-up in cardiac surgery, supporting the feasibility of conducting a large multicenter RCT.

Adjusted regression trend test for a multicenter clinical trial.

PubMed

Quan, H; Capizzi, T

1999-06-01

Studies using a series of increasing doses of a compound, including a zero dose control, are often conducted to study the effect of the compound on the response of interest. For a one-way design, Tukey et al. (1985, Biometrics 41, 295-301) suggested assessing trend by examining the slopes of regression lines under arithmetic, ordinal, and arithmetic-logarithmic dose scalings. They reported the smallest p-value for the three significance tests on the three slopes for safety assessments. Capizzi et al. (1992, Biometrical Journal 34, 275-289) suggested an adjusted trend test, which adjusts the p-value using a trivariate t-distribution, the joint distribution of the three slope estimators. In this paper, we propose an adjusted regression trend test suitable for two-way designs, particularly for multicenter clinical trials. In a step-down fashion, the proposed trend test can be applied to a multicenter clinical trial to compare each dose with the control. This sequential procedure is a closed testing procedure for a trend alternative. Therefore, it adjusts p-values and maintains experimentwise error rate. Simulation results show that the step-down trend test is overall more powerful than a step-down least significant difference test.

Rationale, design and methods of the HEALTHY study behavior intervention component

USDA-ARS?s Scientific Manuscript database

HEALTHY was a multi-center primary prevention trial designed to reduce risk factors for type 2 diabetes in adolescents. Seven centers each recruited six middle schools that were randomized to either intervention or control. The HEALTHY intervention integrated multiple components in nutrition, physic...

The language parallel Pascal and other aspects of the massively parallel processor

NASA Technical Reports Server (NTRS)

Reeves, A. P.; Bruner, J. D.

1982-01-01

A high level language for the Massively Parallel Processor (MPP) was designed. This language, called Parallel Pascal, is described in detail. A description of the language design, a description of the intermediate language, Parallel P-Code, and details for the MPP implementation are included. Formal descriptions of Parallel Pascal and Parallel P-Code are given. A compiler was developed which converts programs in Parallel Pascal into the intermediate Parallel P-Code language. The code generator to complete the compiler for the MPP is being developed independently. A Parallel Pascal to Pascal translator was also developed. The architecture design for a VLSI version of the MPP was completed with a description of fault tolerant interconnection networks. The memory arrangement aspects of the MPP are discussed and a survey of other high level languages is given.

A hybrid framework of first principles molecular orbital calculations and a three-dimensional integral equation theory for molecular liquids: Multi-center molecular Ornstein-Zernike self-consistent field approach

NASA Astrophysics Data System (ADS)

Kido, Kentaro; Kasahara, Kento; Yokogawa, Daisuke; Sato, Hirofumi

2015-07-01

In this study, we reported the development of a new quantum mechanics/molecular mechanics (QM/MM)-type framework to describe chemical processes in solution by combining standard molecular-orbital calculations with a three-dimensional formalism of integral equation theory for molecular liquids (multi-center molecular Ornstein-Zernike (MC-MOZ) method). The theoretical procedure is very similar to the 3D-reference interaction site model self-consistent field (RISM-SCF) approach. Since the MC-MOZ method is highly parallelized for computation, the present approach has the potential to be one of the most efficient procedures to treat chemical processes in solution. Benchmark tests to check the validity of this approach were performed for two solute (solute water and formaldehyde) systems and a simple SN2 reaction (Cl- + CH3Cl → ClCH3 + Cl-) in aqueous solution. The results for solute molecular properties and solvation structures obtained by the present approach were in reasonable agreement with those obtained by other hybrid frameworks and experiments. In particular, the results of the proposed approach are in excellent agreements with those of 3D-RISM-SCF.

A hybrid framework of first principles molecular orbital calculations and a three-dimensional integral equation theory for molecular liquids: multi-center molecular Ornstein-Zernike self-consistent field approach.

PubMed

Kido, Kentaro; Kasahara, Kento; Yokogawa, Daisuke; Sato, Hirofumi

2015-07-07

In this study, we reported the development of a new quantum mechanics/molecular mechanics (QM/MM)-type framework to describe chemical processes in solution by combining standard molecular-orbital calculations with a three-dimensional formalism of integral equation theory for molecular liquids (multi-center molecular Ornstein-Zernike (MC-MOZ) method). The theoretical procedure is very similar to the 3D-reference interaction site model self-consistent field (RISM-SCF) approach. Since the MC-MOZ method is highly parallelized for computation, the present approach has the potential to be one of the most efficient procedures to treat chemical processes in solution. Benchmark tests to check the validity of this approach were performed for two solute (solute water and formaldehyde) systems and a simple SN2 reaction (Cl(-) + CH3Cl → ClCH3 + Cl(-)) in aqueous solution. The results for solute molecular properties and solvation structures obtained by the present approach were in reasonable agreement with those obtained by other hybrid frameworks and experiments. In particular, the results of the proposed approach are in excellent agreements with those of 3D-RISM-SCF.

DUrable polymer-based sTent CHallenge of Promus ElemEnt versus ReSolute integrity (DUTCH PEERS): rationale and study design of a randomized multicenter trial in a Dutch all-comers population.

PubMed

Tandjung, Kenneth; Basalus, Mounir W Z; Sen, Hanim; Jessurun, Gillian A J; Danse, Peter W; Stoel, Martin; Linssen, Gerard C M; Derks, Anita; van Loenhout, Ton T; Nienhuis, Mark B; Hautvast, Raymond W M; von Birgelen, Clemens

2012-04-01

Drug-eluting stents (DES) are increasingly used for the treatment of coronary artery disease. An optimized DES performance is desirable to successfully treat various challenging coronary lesions in a broad population of patients. In response to this demand, third-generation DES with an improved deliverability were developed. Promus Element (Boston Scientific, Natick, MA) and Resolute Integrity (Medtronic Vascular, Santa Rosa, CA) are 2 novel third-generation DES for which limited clinical data are available. Accordingly, we designed the current multicenter study to investigate in an all-comers population whether the clinical outcome is similar after stenting with Promus Element versus Resolute Integrity. DUTCH PEERS is a multicenter, prospective, single-blinded, randomized trial in a Dutch all-comers population. Patients with all clinical syndromes who require percutaneous coronary interventions with DES implantation are eligible. In these patients, the type of DES implanted will be randomized in a 1:1 ratio between Resolute Integrity versus Promus Element. The trial is powered based on a noninferiority hypothesis. For each stent arm, 894 patients will be enrolled, resulting in a total study population of 1,788 patients. The primary end point is the incidence of target vessel failure at 1-year follow-up. DUTCH PEERS is the first randomized multicenter trial with a head-to-head comparison of Promus Element and Resolute Integrity to investigate the safety and efficacy of these third-generation DES. Copyright © 2012 Mosby, Inc. All rights reserved.

Optimal medical treatment versus carotid endarterectomy: the rationale and design of the Aggressive Medical Treatment Evaluation for Asymptomatic Carotid Artery Stenosis (AMTEC) study.

PubMed

Kolos, Igor; Loukianov, Mikhail; Dupik, Nikolay; Boytsov, Sergey; Deev, Alexandr

2015-02-01

Carotid endarterectomy and medical therapy (aspirin) were shown superior to medical therapy alone for asymptomatic (≥ 60%) carotid stenosis. The role of modern medical therapy (statins, antihypertensive treatment, and aspirin) in the treatment of such patients is undefined. Establishing the safety, efficacy, and durability of optimal medical therapy and lifestyle modification requires rigorous comparison with carotid endarterectomy in asymptomatic patients. The objective is to compare the efficacy of carotid endarterectomy + optimal medical therapy versus optimal medical therapy alone in patients with asymptomatic (70-79%) extracranial carotid stenosis. The Aggressive Medical Treatment Evaluation for Asymptomatic Carotid Artery Stenosis study is a prospective, randomized, parallel, two-arm, multicenter trial. Primary end-points will be analyzed using standard time-to-event statistical modeling with adjustment for major baseline covariates. The primary analysis is on an intent-to-treat basis. The primary outcome is nonfatal stroke, nonfatal myocardial infarction, and death during follow-up of up to five-years, and the secondary outcome includes death from any cause and stroke. © 2013 The Authors. International Journal of Stroke © 2013 World Stroke Organization.

Parallelizing serial code for a distributed processing environment with an application to high frequency electromagnetic scattering

NASA Astrophysics Data System (ADS)

Work, Paul R.

1991-12-01

This thesis investigates the parallelization of existing serial programs in computational electromagnetics for use in a parallel environment. Existing algorithms for calculating the radar cross section of an object are covered, and a ray-tracing code is chosen for implementation on a parallel machine. Current parallel architectures are introduced and a suitable parallel machine is selected for the implementation of the chosen ray-tracing algorithm. The standard techniques for the parallelization of serial codes are discussed, including load balancing and decomposition considerations, and appropriate methods for the parallelization effort are selected. A load balancing algorithm is modified to increase the efficiency of the application, and a high level design of the structure of the serial program is presented. A detailed design of the modifications for the parallel implementation is also included, with both the high level and the detailed design specified in a high level design language called UNITY. The correctness of the design is proven using UNITY and standard logic operations. The theoretical and empirical results show that it is possible to achieve an efficient parallel application for a serial computational electromagnetic program where the characteristics of the algorithm and the target architecture critically influence the development of such an implementation.

A Parallel Particle Swarm Optimization Algorithm Accelerated by Asynchronous Evaluations

NASA Technical Reports Server (NTRS)

Venter, Gerhard; Sobieszczanski-Sobieski, Jaroslaw

2005-01-01

A parallel Particle Swarm Optimization (PSO) algorithm is presented. Particle swarm optimization is a fairly recent addition to the family of non-gradient based, probabilistic search algorithms that is based on a simplified social model and is closely tied to swarming theory. Although PSO algorithms present several attractive properties to the designer, they are plagued by high computational cost as measured by elapsed time. One approach to reduce the elapsed time is to make use of coarse-grained parallelization to evaluate the design points. Previous parallel PSO algorithms were mostly implemented in a synchronous manner, where all design points within a design iteration are evaluated before the next iteration is started. This approach leads to poor parallel speedup in cases where a heterogeneous parallel environment is used and/or where the analysis time depends on the design point being analyzed. This paper introduces an asynchronous parallel PSO algorithm that greatly improves the parallel e ciency. The asynchronous algorithm is benchmarked on a cluster assembled of Apple Macintosh G5 desktop computers, using the multi-disciplinary optimization of a typical transport aircraft wing as an example.

Efficacy and Safety of Paliperidone Palmitate 3-Month Formulation for Patients with Schizophrenia: A Randomized, Multicenter, Double-Blind, Noninferiority Study

PubMed Central

Xu, Haiyan; Gopal, Srihari; Nuamah, Isaac; Ravenstijn, Paulien; Janik, Adam; Schotte, Alain; Hough, David; Fleischhacker, Wolfgang W.

2016-01-01

Background: This double-blind, parallel-group, multicenter, phase-3 study was designed to test the noninferiority of paliperidone palmitate 3-month formulation (PP3M) to the currently marketed 1-month formulation (PP1M) in patients (age 18–70 years) with schizophrenia, previously stabilized on PP1M. Methods: After screening (≤3 weeks) and a 17-week, flexible-dosed, open-label phase (PP1M: day 1 [150mg eq. deltoid], day 8 [100mg eq. deltoid.], weeks 5, 9, and 13 [50, 75, 100, or 150mg eq., deltoid/gluteal]), clinically stable patients were randomized (1:1) to PP3M (fixed-dose, 175, 263, 350, or 525mg eq. deltoid/gluteal) or PP1M (fixed-dose, 50, 75, 100, or 150mg eq. deltoid/gluteal) for a 48-week double-blind phase. Results: Overall, 1016/1429 open-label patients entered the double-blind phase (PP3M: n=504; PP1M: n=512) and 842 completed it (including patients with relapse). PP3M was noninferior to PP1M: relapse rates were similar in both groups (PP3M: n=37, 8%; PP1M: n=45, 9%; difference in relapse-free rate: 1.2% [95% CI:-2.7%; 5.1%]) based on Kaplan-Meier estimates (primary efficacy). Secondary endpoint results (changes from double-blind baseline in positive and negative symptom score total and subscale scores, Clinical Global Impression-Severity, and Personal and Social Performance scores) were consistent with primary endpoint results. No clinically relevant differences were observed in pharmacokinetic exposures between PP3M and PP1M. Both groups had similar tolerability profiles; increased weight was the most common treatment-emergent adverse event (double-blind phase; 21% each). No new safety signals were detected. Conclusion: Taken together, PP3M with its 3-month dosing interval is a unique option for relapse prevention in schizophrenia. PMID:26902950

Pilot study assessing the feasibility of applying bilateral subthalamic nucleus deep brain stimulation in very early stage Parkinson's disease: study design and rationale.

PubMed

Charles, David; Tolleson, Christopher; Davis, Thomas L; Gill, Chandler E; Molinari, Anna L; Bliton, Mark J; Tramontana, Michael G; Salomon, Ronald M; Kao, Chris; Wang, Lily; Hedera, Peter; Phibbs, Fenna T; Neimat, Joseph S; Konrad, Peter E

2012-01-01

Deep brain stimulation provides significant symptomatic benefit for people with advanced Parkinson's disease whose symptoms are no longer adequately controlled with medication. Preliminary evidence suggests that subthalamic nucleus stimulation may also be efficacious in early Parkinson's disease, and results of animal studies suggest that it may spare dopaminergic neurons in the substantia nigra. We report the methodology and design of a novel Phase I clinical trial testing the safety and tolerability of deep brain stimulation in early Parkinson's disease and discuss previous failed attempts at neuroprotection. We recently conducted a prospective, randomized, parallel-group, single-blind pilot clinical trial of deep brain stimulation in early Parkinson's disease. Subjects were randomized to receive either optimal drug therapy or deep brain stimulation plus optimal drug therapy. Follow-up visits occurred every six months for a period of two years and included week-long therapy washouts. Thirty subjects with Hoehn & Yahr Stage II idiopathic Parkinson's disease were enrolled over a period of 32 months. Twenty-nine subjects completed all follow-up visits; one patient in the optimal drug therapy group withdrew from the study after baseline. Baseline characteristics for all thirty patients were not significantly different. This study demonstrates that it is possible to recruit and retain subjects in a clinical trial testing deep brain stimulation in early Parkinson's disease. The results of this trial will be used to support the design of a Phase III, multicenter trial investigating the efficacy of deep brain stimulation in early Parkinson's disease.

Pilot Study Assessing the Feasibility of Applying Bilateral Subthalamic Nucleus Deep Brain Stimulation in Very Early Stage Parkinson's Disease: Study design and rationale

PubMed Central

Charles, David; Tolleson, Christopher; Davis, Thomas L.; Gill, Chandler E.; Molinari, Anna L.; Bliton, Mark J.; Tramontana, Michael G.; Salomon, Ronald M.; Kao, Chris; Wang, Lily; Hedera, Peter; Phibbs, Fenna T.; Neimat, Joseph S.; Konrad, Peter E.

2014-01-01

Background Deep brain stimulation provides significant symptomatic benefit for people with advanced Parkinson's disease whose symptoms are no longer adequately controlled with medication. Preliminary evidence suggests that subthalamic nucleus stimulation may also be efficacious in early Parkinson's disease, and results of animal studies suggest that it may spare dopaminergic neurons in the substantia nigra. Objective We report the methodology and design of a novel Phase I clinical trial testing the safety and tolerability of deep brain stimulation in early Parkinson's disease and discuss previous failed attempts at neuroprotection. Methods We recently conducted a prospective, randomized, parallel-group, single-blind pilot clinical trial of deep brain stimulation in early Parkinson's disease. Subjects were randomized to receive either optimal drug therapy or deep brain stimulation plus optimal drug therapy. Follow-up visits occurred every six months for a period of two years and included week-long therapy washouts. Results Thirty subjects with Hoehn & Yahr Stage II idiopathic Parkinson's disease were enrolled over a period of 32 months. Twenty-nine subjects completed all follow-up visits; one patient in the optimal drug therapy group withdrew from the study after baseline. Baseline characteristics for all thirty patients were not significantly different. Conclusions This study demonstrates that it is possible to recruit and retain subjects in a clinical trial testing deep brain stimulation in early Parkinson's disease. The results of this trial will be used to support the design of a Phase III, multicenter trial investigating the efficacy of deep brain stimulation in early Parkinson's disease. PMID:23938229

Parallel optimization algorithms and their implementation in VLSI design

NASA Technical Reports Server (NTRS)

Lee, G.; Feeley, J. J.

1991-01-01

Two new parallel optimization algorithms based on the simplex method are described. They may be executed by a SIMD parallel processor architecture and be implemented in VLSI design. Several VLSI design implementations are introduced. An application example is reported to demonstrate that the algorithms are effective.

Rationale, Design, and Baseline Characteristics of the Utopia Trial for Preventing Diabetic Atherosclerosis Using an SGLT2 Inhibitor: A Prospective, Randomized, Open-Label, Parallel-Group Comparative Study.

PubMed

Katakami, Naoto; Mita, Tomoya; Yoshii, Hidenori; Shiraiwa, Toshihiko; Yasuda, Tetsuyuki; Okada, Yosuke; Umayahara, Yutaka; Kaneto, Hideaki; Osonoi, Takeshi; Yamamoto, Tsunehiko; Kuribayashi, Nobuichi; Maeda, Kazuhisa; Yokoyama, Hiroki; Kosugi, Keisuke; Ohtoshi, Kentaro; Hayashi, Isao; Sumitani, Satoru; Tsugawa, Mamiko; Ohashi, Makoto; Taki, Hideki; Nakamura, Tadashi; Kawashima, Satoshi; Sato, Yasunori; Watada, Hirotaka; Shimomura, Iichiro

2017-10-01

Sodium-glucose co-transporter-2 (SGLT2) inhibitors are anti-diabetic agents that improve glycemic control with a low risk of hypoglycemia and ameliorate a variety of cardiovascular risk factors. The aim of the ongoing study described herein is to investigate the preventive effects of tofogliflozin, a potent and selective SGLT2 inhibitor, on the progression of atherosclerosis in subjects with type 2 diabetes (T2DM) using carotid intima-media thickness (IMT), an established marker of cardiovascular disease (CVD), as a marker. The Study of Using Tofogliflozin for Possible better Intervention against Atherosclerosis for type 2 diabetes patients (UTOPIA) trial is a prospective, randomized, open-label, blinded-endpoint, multicenter, and parallel-group comparative study. The aim was to recruit a total of 340 subjects with T2DM but no history of apparent CVD at 24 clinical sites and randomly allocate these to a tofogliflozin treatment group or a conventional treatment group using drugs other than SGLT2 inhibitors. As primary outcomes, changes in mean and maximum IMT of the common carotid artery during a 104-week treatment period will be measured by carotid echography. Secondary outcomes include changes in glycemic control, parameters related to β-cell function and diabetic nephropathy, the occurrence of CVD and adverse events, and biochemical measurements reflecting vascular function. This is the first study to address the effects of SGLT2 inhibitors on the progression of carotid IMT in subjects with T2DM without a history of CVD. The results will be available in the very near future, and these findings are expected to provide clinical data that will be helpful in the prevention of diabetic atherosclerosis and subsequent CVD. Kowa Co., Ltd. UMIN000017607.

Second International Workshop on Software Engineering and Code Design in Parallel Meteorological and Oceanographic Applications

NASA Technical Reports Server (NTRS)

OKeefe, Matthew (Editor); Kerr, Christopher L. (Editor)

1998-01-01

This report contains the abstracts and technical papers from the Second International Workshop on Software Engineering and Code Design in Parallel Meteorological and Oceanographic Applications, held June 15-18, 1998, in Scottsdale, Arizona. The purpose of the workshop is to bring together software developers in meteorology and oceanography to discuss software engineering and code design issues for parallel architectures, including Massively Parallel Processors (MPP's), Parallel Vector Processors (PVP's), Symmetric Multi-Processors (SMP's), Distributed Shared Memory (DSM) multi-processors, and clusters. Issues to be discussed include: (1) code architectures for current parallel models, including basic data structures, storage allocation, variable naming conventions, coding rules and styles, i/o and pre/post-processing of data; (2) designing modular code; (3) load balancing and domain decomposition; (4) techniques that exploit parallelism efficiently yet hide the machine-related details from the programmer; (5) tools for making the programmer more productive; and (6) the proliferation of programming models (F--, OpenMP, MPI, and HPF).

A Parallel Trade Study Architecture for Design Optimization of Complex Systems

NASA Technical Reports Server (NTRS)

Kim, Hongman; Mullins, James; Ragon, Scott; Soremekun, Grant; Sobieszczanski-Sobieski, Jaroslaw

2005-01-01

Design of a successful product requires evaluating many design alternatives in a limited design cycle time. This can be achieved through leveraging design space exploration tools and available computing resources on the network. This paper presents a parallel trade study architecture to integrate trade study clients and computing resources on a network using Web services. The parallel trade study solution is demonstrated to accelerate design of experiments, genetic algorithm optimization, and a cost as an independent variable (CAIV) study for a space system application.

Conceptual design of a hybrid parallel mechanism for mask exchanging of TMT

NASA Astrophysics Data System (ADS)

Wang, Jianping; Zhou, Hongfei; Li, Kexuan; Zhou, Zengxiang; Zhai, Chao

2015-10-01

Mask exchange system is an important part of the Multi-Object Broadband Imaging Echellette (MOBIE) on the Thirty Meter Telescope (TMT). To solve the problem of stiffness changing with the gravity vector of the mask exchange system in the MOBIE, the hybrid parallel mechanism design method was introduced into the whole research. By using the characteristics of high stiffness and precision of parallel structure, combined with large moving range of serial structure, a conceptual design of a hybrid parallel mask exchange system based on 3-RPS parallel mechanism was presented. According to the position requirements of the MOBIE, the SolidWorks structure model of the hybrid parallel mask exchange robot was established and the appropriate installation position without interfering with the related components and light path in the MOBIE of TMT was analyzed. Simulation results in SolidWorks suggested that 3-RPS parallel platform had good stiffness property in different gravity vector directions. Furthermore, through the research of the mechanism theory, the inverse kinematics solution of the 3-RPS parallel platform was calculated and the mathematical relationship between the attitude angle of moving platform and the angle of ball-hinges on the moving platform was established, in order to analyze the attitude adjustment ability of the hybrid parallel mask exchange robot. The proposed conceptual design has some guiding significance for the design of mask exchange system of the MOBIE on TMT.

Effectiveness of the head CT choice decision aid in parents of children with minor head trauma: study protocol for a multicenter randomized trial

PubMed Central

2014-01-01

Background Blunt head trauma is a common cause of death and disability in children worldwide. Cranial computed tomography (CT), the reference standard for the diagnosis of traumatic brain injury (TBI), exposes children to ionizing radiation which has been linked to the development of brain tumors, leukemia, and other cancers. We describe the methods used to develop and test the effectiveness of a decision aid to facilitate shared decision-making with parents regarding whether to obtain a head CT scan or to further observe their child at home. Methods/Design This is a protocol for a multicenter clinician-level parallel randomized trial to compare an intervention group receiving a decision aid, ‘Head CT Choice’, to a control group receiving usual care. The trial will be conducted at five diverse emergency departments (EDs) in Minnesota and California. Clinicians will be randomized to decision aid or usual care. Parents visiting the ED with children who are less than 18-years-old, have experienced blunt head trauma within 24 hours, and have one or two risk factors for clinically-important TBI (ciTBI) from the Pediatric Emergency Care Applied Research Network head injury clinical prediction rules will be eligible for enrollment. We will measure the effect of Head CT Choice on: (1) parent knowledge regarding their child’s risk of ciTBI, the available diagnostic options, and the risks of radiation exposure associated with a cranial CT scan (primary outcome); (2) parent engagement in the decision-making process; (3) the degree of conflict parents experience related to feeling uninformed; (4) patient and clinician satisfaction with the decision made; (5) the rate of ciTBI at seven days; (6) the proportion of patients in whom a cranial CT scan is obtained; and (7) seven-day healthcare utilization. To capture these outcomes, we will administer parent and clinician surveys immediately after each clinical encounter, obtain video recordings of parent-clinician discussions, administer parent healthcare utilization diaries, analyze hospital billing records, review the electronic medical record, and conduct telephone follow-up. Discussion This multicenter trial will robustly assess the effectiveness of a decision aid on patient-centered outcomes, safety, and healthcare utilization in parents of children with minor head trauma in five diverse EDs. Trial registration ClinicalTrials.gov registration number: NCT02063087. Registration date February 13, 2014. PMID:24965659

Open reduction and internal fixation versus casting for highly comminuted and intra-articular fractures of the distal radius (ORCHID): protocol for a randomized clinical multi-center trial.

PubMed

Bartl, Christoph; Stengel, Dirk; Bruckner, Thomas; Rossion, Inga; Luntz, Steffen; Seiler, Christoph; Gebhard, Florian

2011-03-22

Fractures of the distal radius represent the most common fracture in elderly patients, and often indicate the onset of symptomatic osteoporosis. A variety of treatment options is available, including closed reduction and plaster casting, K-wire-stabilization, external fixation and open reduction and internal fixation (ORIF) with volar locked plating. The latter is widely promoted by clinicians and hardware manufacturers. Closed reduction and cast stabilization for six weeks is a simple, convenient, and ubiquitously available intervention. In contrast, ORIF requires hospitalization, but allows for functional rehabilitation.Given the lack of randomized controlled trials, it remains unclear whether ORIF leads to better functional outcomes one year after injury than closed reduction and casting. ORCHID (Open reduction and internal fixation versus casting for highly comminuted intra-articular fractures of the distal radius) is a pragmatic, randomized, multi-center, clinical trial with two parallel treatment arms. It is planned to include 504 patients in 15 participating centers throughout Germany over a three-year period. Patients are allocated by a central web-based randomization tool.The primary objective is to determine differences in the Short Form 36 (SF-36) Physical Component Score (PCS) between volar locked plating and closed reduction and casting of intraarticular, comminuted distal radius fractures in patients > 65 years of age one year after the fracture. Secondary outcomes include differences in other SF-36 dimensions, the EuroQol-5D questionnaire, the Disability of the Arm, Shoulder, and Hand (DASH) instrument. Also, the range of motion in the affected wrist, activities of daily living, complications (including secondary ORIF and revision surgery), as well as serious adverse events will be assessed. Data obtained during the trial will be used for later health-economic evaluations. The trial architecture involves a central statistical unit, an independent monitoring institute, and a data safety monitoring board. Following approval by the institutional review boards of all participating centers, conduct and reporting will strictly adhere to national and international rules, regulations, and recommendations (e.g., Good Clinical Practice, data safety laws, and EQUATOR/CONSORT proposals). To our knowledge, ORCHID is the first multicenter RCT designed to assess quality of life and functional outcomes following operative treatment compared to conservative treatment of complex, intra-articular fractures of the distal radius in elderly patients. The results are expected to influence future treatment recommendations and policies on an international level. ISRCTN: ISRCTN76120052 Registration date: 31.07.2008; Randomization of first patient: 15.09.2008.

Design innovations and baseline findings in a long-term Parkinson’s trial: NET-PD LS-1

PubMed Central

2012-01-01

Background Based on the pre-clinical and the results of a phase 2 futility study, creatine was selected for an efficacy trial in Parkinson’s disease (PD). We present the design rationale and a description of the study cohort at baseline. Methods A randomized, multicenter, double-blind, parallel group, placebo controlled Phase 3 study of creatine (10 gm daily) in participants with early, treated PD, the Long-term Study – 1 (LS-1) is being conducted by the NINDS Exploratory Trials in Parkinson’s Disease (NET-PD) network. The study utilizes a global statistical test (GST) encompassing multiple clinical rating scales to provide a multidimensional assessment of disease progression. Results A total of 1,741 PD participants from 45 sites in the U.S. and Canada were randomized 1:1 to either 10-gm creatine/day or matching placebo. Participants are being evaluated for a minimum of 5 years. The LS-1 baseline cohort includes participants treated with dopaminergic therapy and generally mild PD. Conclusions LS-1 represents the largest cohort of patients with early treated PD ever enrolled in a clinical trial. The GST approach should provide high power to test the hypothesis that daily administration of creatine (10gm/day) is more effective than placebo in slowing clinical decline in PD between baseline and the 5 year follow-up visit against the background of dopaminergic therapy and best PD care. PMID:23079770

Design and realization of photoelectric instrument binocular optical axis parallelism calibration system

NASA Astrophysics Data System (ADS)

Ying, Jia-ju; Chen, Yu-dan; Liu, Jie; Wu, Dong-sheng; Lu, Jun

2016-10-01

The maladjustment of photoelectric instrument binocular optical axis parallelism will affect the observe effect directly. A binocular optical axis parallelism digital calibration system is designed. On the basis of the principle of optical axis binocular photoelectric instrument calibration, the scheme of system is designed, and the binocular optical axis parallelism digital calibration system is realized, which include four modules: multiband parallel light tube, optical axis translation, image acquisition system and software system. According to the different characteristics of thermal infrared imager and low-light-level night viewer, different algorithms is used to localize the center of the cross reticle. And the binocular optical axis parallelism calibration is realized for calibrating low-light-level night viewer and thermal infrared imager.

Design and Cohort Characteristics of the Social Spectrum Study: A Multicenter Study of the Autism Spectrum among Clinically Referred Children

ERIC Educational Resources Information Center

Duvekot, Jorieke; Hoopen, Leontine W.; Slappendel, Geerte; van der Ende, Jan; Verhulst, Frank C.; van der Sijde, Ad; Greaves-Lord, Kirstin

2017-01-01

This paper provides an overview of the design and cohort characteristics of the Social Spectrum Study: a clinical cohort study that used a two-phase sampling design to identify children at risk for ASD. After screening 1281 children aged 2.5-10 years who had been consecutively referred to one of six mental health services in the Netherlands,…

Parallel Ray Tracing Using the Message Passing Interface

DTIC Science & Technology

2007-09-01

software is available for lens design and for general optical systems modeling. It tends to be designed to run on a single processor and can be very...Cameron, Senior Member, IEEE Abstract—Ray-tracing software is available for lens design and for general optical systems modeling. It tends to be designed to...National Aeronautics and Space Administration (NASA), optical ray tracing, parallel computing, parallel pro- cessing, prime numbers, ray tracing

A Comparison of Parallelism in Interface Designs for Computer-Based Learning Environments

ERIC Educational Resources Information Center

Min, Rik; Yu, Tao; Spenkelink, Gerd; Vos, Hans

2004-01-01

In this paper we discuss an experiment that was carried out with a prototype, designed in conformity with the concept of parallelism and the Parallel Instruction theory (the PI theory). We designed this prototype with five different interfaces, and ran an empirical study in which 18 participants completed an abstract task. The five basic designs…

A multicenter randomized clinical trial of one-rod etonogestrel and two-rod levonorgestrel contraceptive implants with nonrandomized copper-IUD controls: methodology and insertion data.

PubMed

Meirik, Olav; Brache, Vivian; Orawan, Kiriwat; Habib, Ndema Abu; Schmidt, Johannes; Ortayli, Nuriye; Culwell, Kelly; Jackson, Emily; Ali, Moazzam

2013-01-01

Comparative data on etonogestrel and two-rod levonorgestrel contraceptive implants are lacking. A multicenter, open, parallel-group trial with random allocation of implants was performed. For every second implant user, an age-matched woman choosing an intrauterine device (IUD) (TCu380A) was admitted. Methods and data on implant/IUD insertion and 6-week follow-up are reported. A total of 2008 women were randomized to an implant, and 974 women were enrolled in the IUD group. Results from 997 etonogestrel implant users, 997 levonorgestrel implant users and 971 IUD users were analyzed. In the etonogestrel and levonorgestrel groups, respectively, mean insertion durations were 51 (SD 50.2) s and 88 (SD 60.8) s; complication rates at insertion were 0.8% and 0.2%; and at follow-up, 27.2% and 26.7% of women, respectively, had signs or symptoms at the insertion site. At follow-up within 6 weeks after insertion, all implants were in situ, while 2.1% of IUDs were expelled. Performance of etonogestrel and levonorgestrel implants at insertion and within the first 6 weeks is similar. Short-term (6 weeks) continuation rates appear higher for implants than TCu380A. Copyright © 2013 Elsevier Inc. All rights reserved.

Evaluation of the relationship between migraine disorder andoral comorbidities: multicenter randomized clinical trial.

PubMed

Peşkersoy, Cem; Peker, Şule; Kaya, Ayşegül; Ünalp, Aycan; Gökay, Necmi

2016-04-19

Although migraine is a common disorder, there is a lack of research investigating the possible relationship between migraine and oral health. The aim of the present study was to explore the relationship between temporomandibular disorders, bruxism, dental caries, periodontal status, and migraine disorder in a multicenter, parallel, case-controlled clinical study. A total of 2001 participants were divided into two groups: migraineurs (nm = 998) and nonmigraineurs (nh = 1003). International Headache Society's Second Edition of International Classification of Headache Disorders and modified Migraine Disability Assessment surveys were administered to evaluate the level of migraine; a pretreatment questionnaire and the World Health Organization oral health assessment form were used to determine the oral comorbidities and their possible effects on DMFT index, gingival plaque index, existence of temporomandibular disorders, bruxism, and consistency of daily oral hygiene habits. The mean age was 39.6 ± 10.5 years. Female patients seemed to experience migraine attacks more than male patients (64%). The frequency of gastroesophageal reflux was higher in migraineurs in comparison with nonmigraineurs (47%) and tooth wear and abrasion also seemed more frequent (76%). DMFT and plaque index scores showed significant differences for both groups. There is a strong relationship between migraine and oral health status. The existence of reflux in addition to migraine leads to higher dental problems.

Effect of Kangfuxin Solution on Chemo/Radiotherapy-Induced Mucositis in Nasopharyngeal Carcinoma Patients: A Multicenter, Prospective Randomized Phase III Clinical Study

PubMed Central

Luo, Yangkun; Feng, Mei; Fan, Zixuan; Zhu, Xiaodong; Jin, Feng; Li, Rongqing; Wu, Jingbo; Yang, Xia; Jiang, Qinghua; Bai, Hongfang; Huang, Yecai; Lang, Jinyi

2016-01-01

Objective. To evaluate the efficacy and safety of Kangfuxin Solution, a pure Chinese herbal medicine, on mucositis induced by chemoradiotherapy in nasopharyngeal carcinoma patients. Methods. A randomized, parallel-group, multicenter clinical study was performed. A total of 240 patients were randomized to receive either Kangfuxin Solution (test group) or compound borax gargle (control group) during chemoradiotherapy. Oral mucositis, upper gastrointestinal mucositis, and oral pain were evaluated by Common Terminology Criteria for Adverse Events (CTCAE) v3.0 and the Verbal Rating Scale (VRS). Results. Of 240 patients enrolled, 215 were eligible for efficacy analysis. Compared with the control group, the incidence and severity of oral mucositis in the test group were significantly reduced (P = 0.01). The time to different grade of oral mucositis occurrence (grade 1, 2, or 3) was longer in test group (P < 0.01), and the accumulated radiation dose was also higher in test group comparing to the control group (P < 0.05). The test group showed lower incidence of oral pain and gastrointestinal mucositis than the control group (P < 0.01). No significant adverse events were observed. Conclusion. Kangfuxin Solution demonstrated its superiority to compound borax gargle on mucositis induced by chemoradiotherapy. Its safety is acceptable for clinical application. PMID:27375766

Prevention of gestational diabetes through lifestyle intervention: study design and methods of a Finnish randomized controlled multicenter trial (RADIEL).

PubMed

Rönö, Kristiina; Stach-Lempinen, Beata; Klemetti, Miira M; Kaaja, Risto J; Pöyhönen-Alho, Maritta; Eriksson, Johan G; Koivusalo, Saila B

2014-02-14

Maternal overweight, obesity and consequently the incidence of gestational diabetes are increasing rapidly worldwide. The objective of the study was to assess the efficacy and cost-effectiveness of a combined diet and physical activity intervention implemented before, during and after pregnancy in a primary health care setting for preventing gestational diabetes, later type 2 diabetes and other metabolic consequences. RADIEL is a randomized controlled multi-center intervention trial in women at high risk for diabetes (a previous history of gestational diabetes or prepregnancy BMI ≥30 kg/m2). Participants planning pregnancy or in the first half of pregnancy were parallel-group randomized into an intervention arm which received lifestyle counseling and a control arm which received usual care given at their local antenatal clinics. All participants visited a study nurse every three months before and during pregnancy, and at 6 weeks, 6 and 12 months postpartum. Measurements and laboratory tests were performed on all participants with special focus on dietary and exercise habits and metabolic markers.Of the 728 women [mean age 32.5 years (SD 4.7); median parity 1 (range 0-9)] considered to be eligible for the study 235 were non-pregnant and 493 pregnant [mean gestational age 13 (range 6 to 18) weeks] at the time of enrollment. The proportion of nulliparous women was 29.8% (n = 217). Out of all participants, 79.6% of the non-pregnant and 40.4% of the pregnant women had previous gestational diabetes and 20.4% of the non-pregnant and 59.6% of the pregnant women were recruited because of a prepregnancy BMI ≥30 kg/m2. Mean BMI at first visit was 30.1 kg/m2 (SD 6.2) in the non-pregnant and 32.7 kg/m2 (SD 5.6) in the pregnant group. To our knowledge, this is the first randomized lifestyle intervention trial, which includes, besides the pregnancy period, both the prepregnancy and the postpartum period. This study design also provides an opportunity to focus upon the health of the next generation. The study is expected to produce novel information on the optimal timing and setting of interventions and for allocating resources to prevent obesity and diabetes in women of reproductive age.

The Japan Statin Treatment Against Recurrent Stroke (J-STARS): A Multicenter, Randomized, Open-label, Parallel-group Study.

PubMed

Hosomi, Naohisa; Nagai, Yoji; Kohriyama, Tatsuo; Ohtsuki, Toshiho; Aoki, Shiro; Nezu, Tomohisa; Maruyama, Hirofumi; Sunami, Norio; Yokota, Chiaki; Kitagawa, Kazuo; Terayama, Yasuo; Takagi, Makoto; Ibayashi, Setsuro; Nakamura, Masakazu; Origasa, Hideki; Fukushima, Masanori; Mori, Etsuro; Minematsu, Kazuo; Uchiyama, Shinichiro; Shinohara, Yukito; Yamaguchi, Takenori; Matsumoto, Masayasu

2015-09-01

Although statin therapy is beneficial for the prevention of initial stroke, the benefit for recurrent stroke and its subtypes remains to be determined in Asian, in whom stroke profiles are different from Caucasian. This study examined whether treatment with low-dose pravastatin prevents stroke recurrence in ischemic stroke patients. This is a multicenter, randomized, open-label, blinded-endpoint, parallel-group study of patients who experienced non-cardioembolic ischemic stroke. All patients had a total cholesterol level between 4.65 and 6.21 mmol/L at enrollment, without the use of statins. The pravastatin group patients received 10 mg of pravastatin/day; the control group patients received no statins. The primary endpoint was the occurrence of stroke and transient ischemic attack (TIA), with the onset of each stroke subtype set to be one of the secondary endpoints. Although 3000 patients were targeted, 1578 patients (491 female, age 66.2 years) were recruited and randomly assigned to pravastatin group or control group. During the follow-up of 4.9 ± 1.4 years, although total stroke and TIA similarly occurred in both groups (2.56 vs. 2.65%/year), onset of atherothrombotic infarction was less frequent in pravastatin group (0.21 vs. 0.64%/year, p = 0.0047, adjusted hazard ratio 0.33 [95%CI 0.15 to 0.74]). No significant intergroup difference was found for the onset of other stroke subtypes, and for the occurrence of adverse events. Although whether low-dose pravastatin prevents recurrence of total stroke or TIA still needs to be examined in Asian, this study has generated a hypothesis that it may reduce occurrence of stroke due to larger artery atherosclerosis. This study was initially supported by a grant from the Ministry of Health, Labour and Welfare, Japan. After the governmental support expired, it was conducted in collaboration between Hiroshima University and the Foundation for Biomedical Research and Innovation.

Efficacy and safety of guaifenesin for upper back, neck, and shoulder pain: a Phase II proof-of-concept, multicenter, placebo-controlled, repeat-dose, parallel-group study.

PubMed

Collaku, Agron; Yue, Yong; Reed, Kenneth

2017-01-01

Guaifenesin, an over-the-counter (OTC) expectorant, has exhibited muscle relaxant effects preclinically and clinically. This proof-of-principle study explored whether OTC doses of guaifenesin can provide relief from acute upper back, neck, or shoulder muscle spasm and pain. This multicenter, placebo-controlled, repeat-dose, parallel study randomly assigned adults experiencing acute pain and muscle spasm in their upper back, neck, or shoulder to guaifenesin 600 or 1200 mg or matched placebo twice daily (BID) in a 2:2:1:1 ratio for 7 days. The primary end point was the change from baseline in muscle spasm relief, measured using an 11-point numeric rating scale (0=not present to 10=unbearable) recorded twice daily and averaged over the 7-day treatment period. Analyses were performed using a linear mixed model that included treatment as a fixed effect and site as a random effect. A total of 77 subjects were included in the 4 treatment groups. Least squares mean muscle spasm score over 7 days was 1.77 with guaifenesin 1200 mg, 1.42 with its matched placebo, 1.53 with guaifenesin 600 mg, and 1.74 with its matched placebo. Treatment with guaifenesin 1200 mg BID provided 25% greater reduction in mean muscle spasm over its matched placebo and 16% greater reduction than guaifenesin 600 mg BID. These differences were not statistically significant. Based on comparisons of absolute mean values, a consistent directional change in effect was observed, suggesting some benefit from placebo to lower-to-upper doses of guaifenesin with regard to muscle spasm, tension, pain, discomfort, and relaxation. No severe or serious adverse events were reported. Results suggest the potential for OTC dose of guaifenesin 1200 mg BID to provide symptomatic relief of upper back musculoskeletal pain and spasm. Confirmation of this preliminary result in a larger, adequately powered study is needed.

Efficacy and safety of guaifenesin for upper back, neck, and shoulder pain: a Phase II proof-of-concept, multicenter, placebo-controlled, repeat-dose, parallel-group study

PubMed Central

Collaku, Agron; Yue, Yong; Reed, Kenneth

2017-01-01

Background/objective Guaifenesin, an over-the-counter (OTC) expectorant, has exhibited muscle relaxant effects preclinically and clinically. This proof-of-principle study explored whether OTC doses of guaifenesin can provide relief from acute upper back, neck, or shoulder muscle spasm and pain. Methods This multicenter, placebo-controlled, repeat-dose, parallel study randomly assigned adults experiencing acute pain and muscle spasm in their upper back, neck, or shoulder to guaifenesin 600 or 1200 mg or matched placebo twice daily (BID) in a 2:2:1:1 ratio for 7 days. The primary end point was the change from baseline in muscle spasm relief, measured using an 11-point numeric rating scale (0=not present to 10=unbearable) recorded twice daily and averaged over the 7-day treatment period. Analyses were performed using a linear mixed model that included treatment as a fixed effect and site as a random effect. Results A total of 77 subjects were included in the 4 treatment groups. Least squares mean muscle spasm score over 7 days was 1.77 with guaifenesin 1200 mg, 1.42 with its matched placebo, 1.53 with guaifenesin 600 mg, and 1.74 with its matched placebo. Treatment with guaifenesin 1200 mg BID provided 25% greater reduction in mean muscle spasm over its matched placebo and 16% greater reduction than guaifenesin 600 mg BID. These differences were not statistically significant. Based on comparisons of absolute mean values, a consistent directional change in effect was observed, suggesting some benefit from placebo to lower-to-upper doses of guaifenesin with regard to muscle spasm, tension, pain, discomfort, and relaxation. No severe or serious adverse events were reported. Conclusion Results suggest the potential for OTC dose of guaifenesin 1200 mg BID to provide symptomatic relief of upper back musculoskeletal pain and spasm. Confirmation of this preliminary result in a larger, adequately powered study is needed. PMID:28356767

Ten-day quadruple therapy comprising low-dose rabeprazole, bismuth, amoxicillin and tetracycline is an effective and safe first-line treatment for Helicobacter pylori infection in population with high antibiotic resistance: a prospective, multicenter, randomized, parallel-controlled clinical trial in China.

PubMed

Xie, Yong; Zhu, Zhenhua; Wang, Jiangbin; Zhang, Lingxia; Zhang, Zhenyu; Lu, Hong; Zeng, Zhirong; Chen, Shiyao; Liu, Dongsheng; Lv, Nonghua

2018-06-18

Objectives: To investigate the efficacy and safety of 10-day bismuth quadruple therapy with amoxicillin, tetracycline or clarithromycin and different doses of rabeprazole for first-line treatment of Helicobacter pylori infection. Methods: This multicenter, randomized, parallel-controlled clinical trial was conducted between March 2013 and August 2014. A total of 431 H. pylori -infected patients with duodenal ulcers were enrolled and randomized into four treatment groups (1:1:1:1) for 10 days: 1. LR-BAC Group, which received rabeprazole 10 mg b.i.d., bismuth, amoxicillin and clarithromycin; 2. LR-BAT Group, which received rabeprazole 10mg b.i.d., bismuth, amoxicillin and tetracycline; 3. HR-BAC Group, which received rabeprazole 20 mg b.i.d., and bismuth, amoxicillin and clarithromycin; and 4. HR-BAT Group, which received rabeprazole 20 mg b.i.d., bismuth, amoxicillin, tetracycline. Antimicrobial susceptibility was assessed by the E-test method. The primary outcome was H. pylori eradication at 4 weeks after the treatment. Results: The per-protocol (PP) eradication rates in the LR-BAC, LR-BAT, HR-BAC, and HR-BAT groups were 94.1%, 91.9%, 94.8% and 91.9%, respectively, while the intention-to-treat (ITT) eradication rates in those groups were 87.2%, 87.2%, 87.7% and 86%, respectively. There was no significant difference between four groups in PP analysis( P =0.799) and ITT analysis( P =0.985). The efficacies of four treatment therapy were not affected by antibiotics resistance. The adverse events in four treatment groups were similar, CNS and gastrointestinal symptoms were the most common reported. Conclusions: Bismuth-containing quadruple therapy with low-dose rabeprazole, amoxicillin and tetracycline is a good option for first-line treatment of H. pylori infection in population with high antibiotic resistance. Copyright © 2018 Xie et al.

Importance of methodology on (99m)technetium dimercapto-succinic acid scintigraphic image quality: imaging pilot study for RIVUR (Randomized Intervention for Children With Vesicoureteral Reflux) multicenter investigation.

PubMed

Ziessman, Harvey A; Majd, Massoud

2009-07-01

We reviewed our experience with (99m)technetium dimercapto-succinic acid scintigraphy obtained during an imaging pilot study for a multicenter investigation (Randomized Intervention for Children With Vesicoureteral Reflux) of the effectiveness of daily antimicrobial prophylaxis for preventing recurrent urinary tract infection and renal scarring. We analyzed imaging methodology and its relation to diagnostic image quality. (99m)Technetium dimercapto-succinic acid imaging guidelines were provided to participating sites. High-resolution planar imaging with parallel hole or pinhole collimation was required. Two core reviewers evaluated all submitted images. Analysis included appropriate views, presence or lack of patient motion, adequate magnification, sufficient counts and diagnostic image quality. Inter-reader agreement was evaluated. We evaluated 70, (99m)technetium dimercapto-succinic acid studies from 14 institutions. Variability was noted in methodology and image quality. Correlation (r value) between dose administered and patient age was 0.780. For parallel hole collimator imaging good correlation was noted between activity administered and counts (r = 0.800). For pinhole imaging the correlation was poor (r = 0.110). A total of 10 studies (17%) were rejected for quality issues of motion, kidney overlap, inadequate magnification, inadequate counts and poor quality images. The submitting institution was informed and provided with recommendations for improving quality, and resubmission of another study was required. Only 4 studies (6%) were judged differently by the 2 reviewers, and the differences were minor. Methodology and image quality for (99m)technetium dimercapto-succinic acid scintigraphy varied more than expected between institutions. The most common reason for poor image quality was inadequate count acquisition with insufficient attention to the tradeoff between administered dose, length of image acquisition, start time of imaging and resulting image quality. Inter-observer core reader agreement was high. The pilot study ensured good diagnostic quality standardized images for the Randomized Intervention for Children With Vesicoureteral Reflux investigation.

Parallel algorithms for placement and routing in VLSI design. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Brouwer, Randall Jay

1991-01-01

The computational requirements for high quality synthesis, analysis, and verification of very large scale integration (VLSI) designs have rapidly increased with the fast growing complexity of these designs. Research in the past has focused on the development of heuristic algorithms, special purpose hardware accelerators, or parallel algorithms for the numerous design tasks to decrease the time required for solution. Two new parallel algorithms are proposed for two VLSI synthesis tasks, standard cell placement and global routing. The first algorithm, a parallel algorithm for global routing, uses hierarchical techniques to decompose the routing problem into independent routing subproblems that are solved in parallel. Results are then presented which compare the routing quality to the results of other published global routers and which evaluate the speedups attained. The second algorithm, a parallel algorithm for cell placement and global routing, hierarchically integrates a quadrisection placement algorithm, a bisection placement algorithm, and the previous global routing algorithm. Unique partitioning techniques are used to decompose the various stages of the algorithm into independent tasks which can be evaluated in parallel. Finally, results are presented which evaluate the various algorithm alternatives and compare the algorithm performance to other placement programs. Measurements are presented on the parallel speedups available.

Parallel digital forensics infrastructure.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liebrock, Lorie M.; Duggan, David Patrick

2009-10-01

This report documents the architecture and implementation of a Parallel Digital Forensics infrastructure. This infrastructure is necessary for supporting the design, implementation, and testing of new classes of parallel digital forensics tools. Digital Forensics has become extremely difficult with data sets of one terabyte and larger. The only way to overcome the processing time of these large sets is to identify and develop new parallel algorithms for performing the analysis. To support algorithm research, a flexible base infrastructure is required. A candidate architecture for this base infrastructure was designed, instantiated, and tested by this project, in collaboration with New Mexicomore » Tech. Previous infrastructures were not designed and built specifically for the development and testing of parallel algorithms. With the size of forensics data sets only expected to increase significantly, this type of infrastructure support is necessary for continued research in parallel digital forensics. This report documents the implementation of the parallel digital forensics (PDF) infrastructure architecture and implementation.« less

Integrated Task And Data Parallel Programming: Language Design

NASA Technical Reports Server (NTRS)

Grimshaw, Andrew S.; West, Emily A.

1998-01-01

his research investigates the combination of task and data parallel language constructs within a single programming language. There are an number of applications that exhibit properties which would be well served by such an integrated language. Examples include global climate models, aircraft design problems, and multidisciplinary design optimization problems. Our approach incorporates data parallel language constructs into an existing, object oriented, task parallel language. The language will support creation and manipulation of parallel classes and objects of both types (task parallel and data parallel). Ultimately, the language will allow data parallel and task parallel classes to be used either as building blocks or managers of parallel objects of either type, thus allowing the development of single and multi-paradigm parallel applications. 1995 Research Accomplishments In February I presented a paper at Frontiers '95 describing the design of the data parallel language subset. During the spring I wrote and defended my dissertation proposal. Since that time I have developed a runtime model for the language subset. I have begun implementing the model and hand-coding simple examples which demonstrate the language subset. I have identified an astrophysical fluid flow application which will validate the data parallel language subset. 1996 Research Agenda Milestones for the coming year include implementing a significant portion of the data parallel language subset over the Legion system. Using simple hand-coded methods, I plan to demonstrate (1) concurrent task and data parallel objects and (2) task parallel objects managing both task and data parallel objects. My next steps will focus on constructing a compiler and implementing the fluid flow application with the language. Concurrently, I will conduct a search for a real-world application exhibiting both task and data parallelism within the same program m. Additional 1995 Activities During the fall I collaborated with Andrew Grimshaw and Adam Ferrari to write a book chapter which will be included in Parallel Processing in C++ edited by Gregory Wilson. I also finished two courses, Compilers and Advanced Compilers, in 1995. These courses complete my class requirements at the University of Virginia. I have only my dissertation research and defense to complete.

Parallel machine architecture and compiler design facilities

NASA Technical Reports Server (NTRS)

Kuck, David J.; Yew, Pen-Chung; Padua, David; Sameh, Ahmed; Veidenbaum, Alex

1990-01-01

The objective is to provide an integrated simulation environment for studying and evaluating various issues in designing parallel systems, including machine architectures, parallelizing compiler techniques, and parallel algorithms. The status of Delta project (which objective is to provide a facility to allow rapid prototyping of parallelized compilers that can target toward different machine architectures) is summarized. Included are the surveys of the program manipulation tools developed, the environmental software supporting Delta, and the compiler research projects in which Delta has played a role.

Parallel Treatments Design: A Nested Single Subject Design for Comparing Instructional Procedures.

ERIC Educational Resources Information Center

Gast, David L.; Wolery, Mark

1988-01-01

This paper describes the parallel treatments design, a nested single subject experimental design that combines two concurrently implemented multiple probe designs, allows control for effects of extraneous variables through counterbalancing, and replicates its effects across behaviors. Procedural guidelines for the design's use and issues related…

Software Design for Real-Time Systems on Parallel Computers: Formal Specifications.

DTIC Science & Technology

1996-04-01

This research investigated the important issues related to the analysis and design of real - time systems targeted to parallel architectures. In...particular, the software specification models for real - time systems on parallel architectures were evaluated. A survey of current formal methods for...uniprocessor real - time systems specifications was conducted to determine their extensibility in specifying real - time systems on parallel architectures. In

A randomized study comparing outcomes of stapled and hand-sutured anastomoses in patients undergoing open gastrointestinal surgery.

PubMed

Chandramohan, S M; Gajbhiye, Raj Narenda; Agwarwal, Anil; Creedon, Erin; Schwiers, Michael L; Waggoner, Jason R; Tatla, Daljit

2013-08-01

Although stapling is an alternative to hand-suturing in gastrointestinal surgery, recent trials specifically designed to evaluate differences between the two in surgery time, anastomosis time, and return to bowel activity are lacking. This trial compared the outcomes of the two in subjects undergoing open gastrointestinal surgery. Adult subjects undergoing emergency or elective surgery requiring a single gastric, small, or large bowel anastomosis were enrolled into this open-label, prospective, randomized, interventional, parallel, multicenter, controlled trial. Randomization was assigned in a 1:1 ratio between the hand-sutured group (n = 138) and the stapled group (n = 142). Anastomosis time, surgery time, and time to bowel activity were collected and compared as primary endpoints. A total of 280 subjects were enrolled from April 2009 to September 2010. Only the time of anastomosis was significantly different between the two arms: 17.6 ± 1.90 min (stapled) and 20.6 ± 1.90 min (hand-sutured). This difference was deemed not clinically or economically meaningful. Safety outcomes and other secondary endpoints were similar between the two arms. Mechanical stapling is faster than hand-suturing for the construction of gastrointestinal anastomoses. Apart from this, stapling and hand-suturing are similar with respect to the outcomes measured in this trial.

Optimizing Outcome Assessment in Multicenter TBI Trials: Perspectives From TRACK-TBI and the TBI Endpoints Development Initiative.

PubMed

Bodien, Yelena G; McCrea, Michael; Dikmen, Sureyya; Temkin, Nancy; Boase, Kim; Machamer, Joan; Taylor, Sabrina R; Sherer, Mark; Levin, Harvey; Kramer, Joel H; Corrigan, John D; McAllister, Thomas W; Whyte, John; Manley, Geoffrey T; Giacino, Joseph T

Traumatic brain injury (TBI) is a global public health problem that affects the long-term cognitive, physical, and psychological health of patients, while also having a major impact on family and caregivers. In stark contrast to the effective trials that have been conducted in other neurological diseases, nearly 30 studies of interventions employed during acute hospital care for TBI have failed to identify treatments that improve outcome. Many factors may confound the ability to detect true and meaningful treatment effects. One promising area for improving the precision of intervention studies is to optimize the validity of the outcome assessment battery by using well-designed tools and data collection strategies to reduce variability in the outcome data. The Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study, conducted at 18 sites across the United States, implemented a multidimensional outcome assessment battery with 22 measures aimed at characterizing TBI outcome up to 1 year postinjury. In parallel, through the TBI Endpoints Development (TED) Initiative, federal agencies and investigators have partnered to identify the most valid, reliable, and sensitive outcome assessments for TBI. Here, we present lessons learned from the TRACK-TBI and TED initiatives aimed at optimizing the validity of outcome assessment in TBI.

Double-blind, randomized, controlled trial of rasagiline as monotherapy in early Parkinson's disease patients.

PubMed

Stern, Matthew B; Marek, Kenneth L; Friedman, Joseph; Hauser, Robert A; LeWitt, Peter A; Tarsy, Daniel; Olanow, C Warren

2004-08-01

Rasagiline (N-propargyl-1(R)-aminoindan) mesylate is a potent, selective, and irreversible monoamine oxidase-B inhibitor. This study was designed to evaluate the safety, tolerability, and preliminary efficacy of rasagiline monotherapy in early Parkinson's disease (PD) patients not receiving levodopa. The study was performed as a multicenter, parallel-group, double-blind, randomized, placebo-controlled, 10-week study. Fifty-six PD patients were randomly assigned to rasagiline mesylate 1, 2, or 4 mg once daily, or placebo. A 3-week dose-escalation period was followed by a 7-week maintenance phase. At week 10, the mean (+/-SE) changes from baseline in total Unified Parkinson's Disease Rating Scale (UPDRS) score were -1.8 (+/-1.3), -3.6 (+/-1.7), -3.6 (+/-1.2), and -0.5 (+/-0.8) in the rasagiline 1, 2, and 4 mg/day and placebo groups, respectively. Analysis of responders showed that 28% of patients (12 of 43) receiving rasagiline had an improvement in total UPDRS score of greater than 30%, compared with none of the patients receiving placebo (P < 0.05, Fisher's exact test). The frequency and types of adverse events reported by rasagiline-treated and placebo-treated patients were similar. These results suggest that rasagiline monotherapy is well tolerated and efficacious in early PD. Copyright 2004 Movement Disorder Society

Critical appraisal of clinical trials in multiple system atrophy: Toward better quality.

PubMed

Castro Caldas, Ana; Levin, Johannes; Djaldetti, Ruth; Rascol, Olivier; Wenning, Gregor; Ferreira, Joaquim J

2017-10-01

Multiple system atrophy (MSA) is a rare neurodegenerative disease of undetermined cause. Although many clinical trials have been conducted, there is still no treatment that cures the disease or slows its progression. We sought to assess the clinical trials, methodology, and quality of reporting of clinical trails conducted in MSA patients. We conducted a systematic review of all trials with at least 1 MSA patient subject to any pharmacological/nonpharmacological interventions. Two independent reviewers evaluated the methodological characteristics and quality of reporting of trials. A total of 60 clinical trials were identified, including 1375 MSA patients. Of the trials, 51% (n = 31) were single-arm studies. A total of 28% (n = 17) had a parallel design, half of which (n = 13) were placebo controlled. Of the studies, 8 (13.3%) were conducted in a multicenter setting, 3 of which were responsible for 49.3% (n = 678) of the total included MSA patients. The description of primary outcomes was unclear in 60% (n = 40) of trials. Only 10 (16.7%) clinical trials clearly described the randomization process. Blinding of the participants, personnel, and outcome assessments were at high risk of bias in the majority of studies. The number of dropouts/withdrawals was high (n = 326, 23.4% among the included patients). Overall, the design and quality of reporting of the reviewed studies is unsatisfactory. The most frequent clinical trials were small and single centered. Inadequate reporting was related to the information on the randomization process, sequence generation, allocation concealment, blinding of participants, and sample size calculations. Although improved during the recent years, methodological quality and trial design need to be optimized to generate more informative results. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

Testing for carryover effects after cessation of treatments: a design approach.

PubMed

Sturdevant, S Gwynn; Lumley, Thomas

2016-08-02

Recently, trials addressing noisy measurements with diagnosis occurring by exceeding thresholds (such as diabetes and hypertension) have been published which attempt to measure carryover - the impact that treatment has on an outcome after cessation. The design of these trials has been criticised and simulations have been conducted which suggest that the parallel-designs used are not adequate to test this hypothesis; two solutions are that either a differing parallel-design or a cross-over design could allow for diagnosis of carryover. We undertook a systematic simulation study to determine the ability of a cross-over or a parallel-group trial design to detect carryover effects on incident hypertension in a population with prehypertension. We simulated blood pressure and focused on varying criteria to diagnose systolic hypertension. Using the difference in cumulative incidence hypertension to analyse parallel-group or cross-over trials resulted in none of the designs having acceptable Type I error rate. Under the null hypothesis of no carryover the difference is well above the nominal 5 % error rate. When a treatment is effective during the intervention period, reliable testing for a carryover effect is difficult. Neither parallel-group nor cross-over designs using the difference in cumulative incidence appear to be a feasible approach. Future trials should ensure their design and analysis is validated by simulation.

Prevention of Posttraumatic Contractures with Ketotifen (PERK)

DTIC Science & Technology

2017-10-01

opportunity to design a Phase III RCT on the use of ketotifen in post -traumatic joint contractures. The goal is to design and develop the infrastructure to...Research (CIHR) for the Phase III RCT. 2. KEYWORDS Post -traumatic contractures, elbow fractures, randomized clinical trial, multicenter, ketotifen...application to use ketotifen in post -traumatic joint contracture prevention was submitted to the Division of Pulmonary, Allergy, and Rheumatology

Design Sketches For Optical Crossbar Switches Intended For Large-Scale Parallel Processing Applications

NASA Astrophysics Data System (ADS)

Hartmann, Alfred; Redfield, Steve

1989-04-01

This paper discusses design of large-scale (1000x 1000) optical crossbar switching networks for use in parallel processing supercom-puters. Alternative design sketches for an optical crossbar switching network are presented using free-space optical transmission with either a beam spreading/masking model or a beam steering model for internodal communications. The performances of alternative multiple access channel communications protocol-unslotted and slotted ALOHA and carrier sense multiple access (CSMA)-are compared with the performance of the classic arbitrated bus crossbar of conventional electronic parallel computing. These comparisons indicate an almost inverse relationship between ease of implementation and speed of operation. Practical issues of optical system design are addressed, and an optically addressed, composite spatial light modulator design is presented for fabrication to arbitrarily large scale. The wide range of switch architecture, communications protocol, optical systems design, device fabrication, and system performance problems presented by these design sketches poses a serious challenge to practical exploitation of highly parallel optical interconnects in advanced computer designs.

National Combustion Code: Parallel Implementation and Performance

NASA Technical Reports Server (NTRS)

Quealy, A.; Ryder, R.; Norris, A.; Liu, N.-S.

2000-01-01

The National Combustion Code (NCC) is being developed by an industry-government team for the design and analysis of combustion systems. CORSAIR-CCD is the current baseline reacting flow solver for NCC. This is a parallel, unstructured grid code which uses a distributed memory, message passing model for its parallel implementation. The focus of the present effort has been to improve the performance of the NCC flow solver to meet combustor designer requirements for model accuracy and analysis turnaround time. Improving the performance of this code contributes significantly to the overall reduction in time and cost of the combustor design cycle. This paper describes the parallel implementation of the NCC flow solver and summarizes its current parallel performance on an SGI Origin 2000. Earlier parallel performance results on an IBM SP-2 are also included. The performance improvements which have enabled a turnaround of less than 15 hours for a 1.3 million element fully reacting combustion simulation are described.

A Robust and Scalable Software Library for Parallel Adaptive Refinement on Unstructured Meshes

NASA Technical Reports Server (NTRS)

Lou, John Z.; Norton, Charles D.; Cwik, Thomas A.

1999-01-01

The design and implementation of Pyramid, a software library for performing parallel adaptive mesh refinement (PAMR) on unstructured meshes, is described. This software library can be easily used in a variety of unstructured parallel computational applications, including parallel finite element, parallel finite volume, and parallel visualization applications using triangular or tetrahedral meshes. The library contains a suite of well-designed and efficiently implemented modules that perform operations in a typical PAMR process. Among these are mesh quality control during successive parallel adaptive refinement (typically guided by a local-error estimator), parallel load-balancing, and parallel mesh partitioning using the ParMeTiS partitioner. The Pyramid library is implemented in Fortran 90 with an interface to the Message-Passing Interface (MPI) library, supporting code efficiency, modularity, and portability. An EM waveguide filter application, adaptively refined using the Pyramid library, is illustrated.

Filgrastim mobilization and collection of allogeneic blood progenitor cells from adult family donors: first interim report of a prospective German multicenter study.

PubMed

Beelen, D W; Ottinger, H; Kolbe, K; Pönisch, W; Sayer, H G; Knauf, W; Stockschläder, M; Scheid, C; Schaefer, U W

2002-12-01

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) mobilized peripheral blood progenitor cells (PBPCs) from healthy individuals are a rapidly emerging alternative source to bone marrow for allogeneic transplantation. Although widely applied in the meantime, only limited information on feasibility and safety of mobilization and collection of PBPCs is currently available from prospective multicenter studies specifically designed to investigate this donation modality. This ongoing multicenter study on the performance as well as the short- and long-term safety profile of rhG-CSF-induced mobilization and collection of PBPCs was initiated in October 1999. The study is designed to recruit a total of 300 healthy family donors who will be followed regularly for a period of 5 years after donation. The first interim report presented here summarizes results obtained after enrollment of 150 donors from nine German institutions. The study protocol allowed the individual choice between two dose regimens of rh-CSF (10 micro g/kg per day vs 2x8 micro g/kg per day of donor body weight). The primary endpoint was defined as a yield of > or =5x10(6) CD34(+) cells/kg of recipient body weight in a single leukapheresis product. This endpoint was attained by 50% of donors receiving the lower rhG-CSF dose regimen and by 75% of donors with the higher dose regimen ( p<0.0009). A total of 478 acute adverse events attributable to the mobilization procedure were recorded and manifested predominantly as transient bone pain and headaches (80%). No persistent hematologic or nonhematologic adverse events have occurred in this study so far. Thus, the current experience in a prospective multicenter study supports previous single-center and retrospective registry reports in that the collection of PBPCs after rhG-CSF mobilization is feasible and associated with frequent, but generally mild and acceptable side effects.

Multicenter Evaluation Of Coronary Dual-Source CT angiography in patients with intermediate Risk of Coronary Artery Stenoses (MEDIC): study design and rationale.

PubMed

Marwan, Mohamed; Hausleiter, Jörg; Abbara, Suhny; Hoffmann, Udo; Becker, Christoph; Ovrehus, Kristian; Ropers, Dieter; Bathina, Ravi; Berman, Dan; Anders, Katharina; Uder, Michael; Meave, Aloha; Alexánderson, Erick; Achenbach, Stephan

2014-01-01

The diagnostic performance of multidetector row CT to detect coronary artery stenosis has been evaluated in numerous single-center studies, with only limited data from large cohorts with low-to-intermediate likelihood of coronary disease and in multicenter trials. The Multicenter Evaluation of Coronary Dual-Source CT Angiography in Patients with Intermediate Risk of Coronary Artery Stenoses (MEDIC) trial determines the accuracy of dual-source CT (DSCT) to identify persons with at least 1 coronary artery stenosis among patients with low-to-intermediate pretest likelihood of disease. The MEDIC trial was designed as a prospective, multicenter, international trial to evaluate the diagnostic performance of DSCT for the detection of coronary artery stenosis compared with invasive coronary angiography. The study includes 8 sites in Germany, India, Mexico, the United States, and Denmark. The study population comprises patients referred for a diagnostic coronary angiogram because of suspected coronary artery disease with an intermediate pretest likelihood as determined by sex, age, and symptoms. All evaluations are performed by blinded core laboratory readers. The primary outcome of the MEDIC trial is the accuracy of DSCT to identify the presence of coronary artery stenoses with a luminal diameter narrowing of 50% or more on a per-vessel basis. Secondary outcome parameters include per-patient and per-segment diagnostic accuracy for 50% stenoses and accuracy to identify stenoses of 70% or more. Furthermore, secondary outcome parameters include the influence of heart rate, Agatston score, body weight, body mass index, image quality, and diagnostic confidence on the accuracy to detect coronary artery stenoses >50% on a per-vessel basis. The results of the MEDIC trial will assess the clinical utility of coronary CT angiography in the evaluation of patients with intermediate pretest likelihood of coronary artery disease. Copyright © 2014 Society of Cardiovascular Computed Tomography. All rights reserved.

Design of a massively parallel computer using bit serial processing elements

NASA Technical Reports Server (NTRS)

Aburdene, Maurice F.; Khouri, Kamal S.; Piatt, Jason E.; Zheng, Jianqing

1995-01-01

A 1-bit serial processor designed for a parallel computer architecture is described. This processor is used to develop a massively parallel computational engine, with a single instruction-multiple data (SIMD) architecture. The computer is simulated and tested to verify its operation and to measure its performance for further development.

Effect of structured physical activity on respiratory outcomes in sedentary elderly adults with mobility limitations

USDA-ARS?s Scientific Manuscript database

OBJECTIVES: To evaluate the effect of structured physical activity on respiratory outcomes in community dwelling elderly adults with mobility limitations. DESIGN: Multicenter, randomized trial of physical activity vs health education, with respiratory variables prespecified as tertiary outcomes over...

Lifestyle interventions and independence for elders study: Recruitment and baseline characteristics

USDA-ARS?s Scientific Manuscript database

Recruitment of older adults into long-term clinical trials involving behavioral interventions is a significant challenge. The Lifestyle Interventions and Independence for Elders (LIFE) Study is a Phase 3 multicenter randomized controlled multisite trial, designed to compare the effects of a moderate...

Use of biodegradable polylactic acid barrier materials in the treatment of grade II periodontal furcation defects in humans--Part I: A multicenter investigative clinical study.

PubMed

Vernino, A R; Ringeisen, T A; Wang, H L; Derhalli, M; Rapley, J; Nechamkin, S J; Brekke, J

1998-12-01

This study evaluated two bioresorbable polylactic acid barriers (Epi-Guide and Guidor) to determine if design differences were of therapeutic significance in the treatment of Grade II furcation defects in humans. Forty patients with bilaterally matched, Grade II furcation defects in maxillary or mandibular first or second molars were treated in a multicenter study. Comprehensive initial periodontal therapy, followed by defect debridement and root preparation, preceded randomized membrane placement. Data collected from all three investigative centers were pooled and analyzed using an analysis of variance appropriate for a counterbalancing design. Both barrier types produced measurable improvements of clinical probing values. Barrier exposure scores taken through the eighth week postoperative revealed that Epi-Guide was less likely to become exposed than Guidor. The findings of this study, which was conducted over a 12-month period, demonstrated that Epi-Guide and Guidor were comparable as measured by clinical probing determinations.

Concurrent Collections (CnC): A new approach to parallel programming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knobe, Kathleen

2010-05-07

A common approach in designing parallel languages is to provide some high level handles to manipulate the use of the parallel platform. This exposes some aspects of the target platform, for example, shared vs. distributed memory. It may expose some but not all types of parallelism, for example, data parallelism but not task parallelism. This approach must find a balance between the desire to provide a simple view for the domain expert and provide sufficient power for tuning. This is hard for any given architecture and harder if the language is to apply to a range of architectures. Either simplicitymore » or power is lost. Instead of viewing the language design problem as one of providing the programmer with high level handles, we view the problem as one of designing an interface. On one side of this interface is the programmer (domain expert) who knows the application but needs no knowledge of any aspects of the platform. On the other side of the interface is the performance expert (programmer or program) who demands maximal flexibility for optimizing the mapping to a wide range of target platforms (parallel / serial, shared / distributed, homogeneous / heterogeneous, etc.) but needs no knowledge of the domain. Concurrent Collections (CnC) is based on this separation of concerns. The talk will present CnC and its benefits. About the speaker. Kathleen Knobe has focused throughout her career on parallelism especially compiler technology, runtime system design and language design. She worked at Compass (aka Massachusetts Computer Associates) from 1980 to 1991 designing compilers for a wide range of parallel platforms for Thinking Machines, MasPar, Alliant, Numerix, and several government projects. In 1991 she decided to finish her education. After graduating from MIT in 1997, she joined Digital Equipment’s Cambridge Research Lab (CRL). She stayed through the DEC/Compaq/HP mergers and when CRL was acquired and absorbed by Intel. She currently works in the Software and Services Group / Technology Pathfinding and Innovation.« less

Concurrent Collections (CnC): A new approach to parallel programming

ScienceCinema

Knobe, Kathleen

2018-04-16

A common approach in designing parallel languages is to provide some high level handles to manipulate the use of the parallel platform. This exposes some aspects of the target platform, for example, shared vs. distributed memory. It may expose some but not all types of parallelism, for example, data parallelism but not task parallelism. This approach must find a balance between the desire to provide a simple view for the domain expert and provide sufficient power for tuning. This is hard for any given architecture and harder if the language is to apply to a range of architectures. Either simplicity or power is lost. Instead of viewing the language design problem as one of providing the programmer with high level handles, we view the problem as one of designing an interface. On one side of this interface is the programmer (domain expert) who knows the application but needs no knowledge of any aspects of the platform. On the other side of the interface is the performance expert (programmer or program) who demands maximal flexibility for optimizing the mapping to a wide range of target platforms (parallel / serial, shared / distributed, homogeneous / heterogeneous, etc.) but needs no knowledge of the domain. Concurrent Collections (CnC) is based on this separation of concerns. The talk will present CnC and its benefits. About the speaker. Kathleen Knobe has focused throughout her career on parallelism especially compiler technology, runtime system design and language design. She worked at Compass (aka Massachusetts Computer Associates) from 1980 to 1991 designing compilers for a wide range of parallel platforms for Thinking Machines, MasPar, Alliant, Numerix, and several government projects. In 1991 she decided to finish her education. After graduating from MIT in 1997, she joined Digital Equipment’s Cambridge Research Lab (CRL). She stayed through the DEC/Compaq/HP mergers and when CRL was acquired and absorbed by Intel. She currently works in the Software and Services Group / Technology Pathfinding and Innovation.

Parallel integer sorting with medium and fine-scale parallelism

NASA Technical Reports Server (NTRS)

Dagum, Leonardo

1993-01-01

Two new parallel integer sorting algorithms, queue-sort and barrel-sort, are presented and analyzed in detail. These algorithms do not have optimal parallel complexity, yet they show very good performance in practice. Queue-sort designed for fine-scale parallel architectures which allow the queueing of multiple messages to the same destination. Barrel-sort is designed for medium-scale parallel architectures with a high message passing overhead. The performance results from the implementation of queue-sort on a Connection Machine CM-2 and barrel-sort on a 128 processor iPSC/860 are given. The two implementations are found to be comparable in performance but not as good as a fully vectorized bucket sort on the Cray YMP.

Design of the multicenter standardized supervised exercise training intervention for the claudication: exercise vs endoluminal revascularization (CLEVER) study.

PubMed

Bronas, Ulf G; Hirsch, Alan T; Murphy, Timothy; Badenhop, Dalynn; Collins, Tracie C; Ehrman, Jonathan K; Ershow, Abby G; Lewis, Beth; Treat-Jacobson, Diane J; Walsh, M Eileen; Oldenburg, Niki; Regensteiner, Judith G

2009-11-01

The CLaudication: Exercise Vs Endoluminal Revascularization (CLEVER) study is the first randomized, controlled, clinical, multicenter trial that is evaluating a supervised exercise program compared with revascularization procedures to treat claudication. In this report, the methods and dissemination techniques of the supervised exercise training intervention are described. A total of 217 participants are being recruited and randomized to one of three arms: (1) optimal medical care; (2) aortoiliac revascularization with stent; or (3) supervised exercise training. Of the enrolled patients, 84 will receive supervised exercise therapy. Supervised exercise will be administered according to a protocol designed by a central CLEVER exercise training committee based on validated methods previously used in single center randomized control trials. The protocol will be implemented at each site by an exercise committee member using training methods developed and standardized by the exercise training committee. The exercise training committee reviews progress and compliance with the protocol of each participant weekly. In conclusion, a multicenter approach to disseminate the supervised exercise training technique and to evaluate its efficacy, safety and cost-effectiveness for patients with claudication due to peripheral arterial disease (PAD) is being evaluated for the first time in CLEVER. The CLEVER study will further establish the role of supervised exercise training in the treatment of claudication resulting from PAD and provide standardized methods for use of supervised exercise training in future PAD clinical trials as well as in clinical practice.

Design considerations for parallel graphics libraries

NASA Technical Reports Server (NTRS)

Crockett, Thomas W.

1994-01-01

Applications which run on parallel supercomputers are often characterized by massive datasets. Converting these vast collections of numbers to visual form has proven to be a powerful aid to comprehension. For a variety of reasons, it may be desirable to provide this visual feedback at runtime. One way to accomplish this is to exploit the available parallelism to perform graphics operations in place. In order to do this, we need appropriate parallel rendering algorithms and library interfaces. This paper provides a tutorial introduction to some of the issues which arise in designing parallel graphics libraries and their underlying rendering algorithms. The focus is on polygon rendering for distributed memory message-passing systems. We illustrate our discussion with examples from PGL, a parallel graphics library which has been developed on the Intel family of parallel systems.

Designing Feature and Data Parallel Stochastic Coordinate Descent Method forMatrix and Tensor Factorization

DTIC Science & Technology

2016-05-11

AFRL-AFOSR-JP-TR-2016-0046 Designing Feature and Data Parallel Stochastic Coordinate Descent Method for Matrix and Tensor Factorization U Kang Korea...maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or   any other aspect...Designing Feature and Data Parallel Stochastic Coordinate Descent Method for Matrix and Tensor Factorization 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA2386

Design innovations and baseline findings in a long-term Parkinson's trial: the National Institute of Neurological Disorders and Stroke Exploratory Trials in Parkinson's Disease Long-Term Study-1.

PubMed

Elm, Jordan J

2012-10-01

Based on the preclinical data and the results of a phase II futility study, creatine was selected for an efficacy trial in Parkinson's disease (PD). We present the design rationale and a description of the study cohort at baseline. A randomized, multicenter, double-blind, parallel-group, placebo-controlled phase III study of creatine (10 g daily) in participants with early, treated PD, the Long-term Study-1 (LS-1), is being conducted by the National Institute of Neurological Disorders and Stroke Exploratory Trials in Parkinson's Disease network. The study utilizes a global statistical test (GST) encompassing five clinical rating scales to provide a multidimensional assessment of disease progression. A total of 1,741 PD participants from 45 sites in the United States and Canada were randomized 1:1 to either 10 g of creatine/day or matching placebo. Participants are being evaluated for a minimum of 5 years. The LS-1 baseline cohort includes participants treated with dopaminergic therapy and generally mild PD. LS-1 represents the largest cohort of patients with early treated PD ever enrolled in a clinical trial. The GST approach should provide high power to test the hypothesis that daily administration of creatine (10 g/day) is more effective than placebo in slowing clinical decline in PD between baseline and the 5-year follow-up visit against the background of dopaminergic therapy and best PD care. Copyright © 2012 Movement Disorder Society.

Designing and conducting a randomized trial for pandemic critical illness: the 2009 H1N1 influenza pandemic.

PubMed

Annane, Djillali; Antona, Marion; Lehmann, Blandine; Kedzia, Cecile; Chevret, Sylvie

2012-01-01

To analyze the hurdles in implementing a randomized trial of corticosteroids for severe 2009 H1N1 influenza infections. This was an investigator-led, multicenter, randomized, placebo-controlled, double-blind trial of corticosteroids in ICU patients with 2009 H1N1 influenza pneumonia requiring mechanical ventilation. The feasibility of and hurdles in designing and initiating a phase III trial in a short-lived pandemic crisis were analyzed. The regulatory agency and ethics committee approved the study's scientific, financial, and ethical aspects within 4 weeks. Hydrocortisone and placebo were prepared centrally and shipped to participating hospitals within 6 weeks. The inclusion period started on November 9, 2009. From August 1, 2009 to March 8, 2010, only 205/224 ICU patients with H1N1 infections required mechanical ventilation. The peak of the wave was missed by 2-3 weeks and only 26 patients were randomized. The two main reasons for non-inclusion were patients' admission before the beginning of the trial and ICU personnel overwhelmed by clinical duties. Parallel rather than sequential regulatory and ethics approval, and preparation and masking of study drugs by local pharmacists would have allowed the study to start 1 month earlier and before the peak of the "flu" wave. A dedicated research team in each participating center would have increased the ratio of screened to randomized patients. This report highlights the main hurdles in implementing a randomized trial for a pandemic critical illness and proposes solutions for future trials.

The Importance of Considering Differences in Study Design in Network Meta-analysis: An Application Using Anti-Tumor Necrosis Factor Drugs for Ulcerative Colitis.

PubMed

Cameron, Chris; Ewara, Emmanuel; Wilson, Florence R; Varu, Abhishek; Dyrda, Peter; Hutton, Brian; Ingham, Michael

2017-11-01

Adaptive trial designs present a methodological challenge when performing network meta-analysis (NMA), as data from such adaptive trial designs differ from conventional parallel design randomized controlled trials (RCTs). We aim to illustrate the importance of considering study design when conducting an NMA. Three NMAs comparing anti-tumor necrosis factor drugs for ulcerative colitis were compared and the analyses replicated using Bayesian NMA. The NMA comprised 3 RCTs comparing 4 treatments (adalimumab 40 mg, golimumab 50 mg, golimumab 100 mg, infliximab 5 mg/kg) and placebo. We investigated the impact of incorporating differences in the study design among the 3 RCTs and presented 3 alternative methods on how to convert outcome data derived from one form of adaptive design to more conventional parallel RCTs. Combining RCT results without considering variations in study design resulted in effect estimates that were biased against golimumab. In contrast, using the 3 alternative methods to convert outcome data from one form of adaptive design to a format more consistent with conventional parallel RCTs facilitated more transparent consideration of differences in study design. This approach is more likely to yield appropriate estimates of comparative efficacy when conducting an NMA, which includes treatments that use an alternative study design. RCTs based on adaptive study designs should not be combined with traditional parallel RCT designs in NMA. We have presented potential approaches to convert data from one form of adaptive design to more conventional parallel RCTs to facilitate transparent and less-biased comparisons.

A multicenter, randomized, controlled trial of osteopathic manipulative treatment on preterms.

PubMed

Cerritelli, Francesco; Pizzolorusso, Gianfranco; Renzetti, Cinzia; Cozzolino, Vincenzo; D'Orazio, Marianna; Lupacchini, Mariacristina; Marinelli, Benedetta; Accorsi, Alessandro; Lucci, Chiara; Lancellotti, Jenny; Ballabio, Silvia; Castelli, Carola; Molteni, Daniela; Besana, Roberto; Tubaldi, Lucia; Perri, Francesco Paolo; Fusilli, Paola; D'Incecco, Carmine; Barlafante, Gina

2015-01-01

Despite some preliminary evidence, it is still largely unknown whether osteopathic manipulative treatment improves preterm clinical outcomes. The present multi-center randomized single blind parallel group clinical trial enrolled newborns who met the criteria for gestational age between 29 and 37 weeks, without any congenital complication from 3 different public neonatal intensive care units. Preterm infants were randomly assigned to usual prenatal care (control group) or osteopathic manipulative treatment (study group). The primary outcome was the mean difference in length of hospital stay between groups. A total of 695 newborns were randomly assigned to either the study group (n= 352) or the control group (n=343). A statistical significant difference was observed between the two groups for the primary outcome (13.8 and 17.5 days for the study and control group respectively, p<0.001, effect size: 0.31). Multivariate analysis showed a reduction of the length of stay of 3.9 days (95% CI -5.5 to -2.3, p<0.001). Furthermore, there were significant reductions with treatment as compared to usual care in cost (difference between study and control group: 1,586.01€; 95% CI 1,087.18 to 6,277.28; p<0.001) but not in daily weight gain. There were no complications associated to the intervention. Osteopathic treatment reduced significantly the number of days of hospitalization and is cost-effective on a large cohort of preterm infants.

Crestal sinus lift with sequential drills and simultaneous implant placement in sites with <5 mm of native bone: a multicenter retrospective study.

PubMed

Bernardello, Fabio; Righi, Davide; Cosci, Ferdinando; Bozzoli, Paolo; Soardi, Carlo Maria; Carlo, Maria Soardi; Spinato, Sergio

2011-12-01

The aim of this multicenter retrospective clinical study was to evaluate the survival rate of implants placed in the posterior maxilla with a residual bone height of <5 mm. One hundred seventeen patients, recruited from 6 different centers, had 134 implants placed below the maxillary sinus. The patient population consisted of 52 men and 65 women ranging in age from 39 to 78 years (mean age, 53.2 years). Sinus lift procedures were performed following a crestal approach using a specific sequence of drills (Cosci's technique). All implants were submerged. Periapical radiographs were obtained with a paralleling technique and were digitized. The pattern of bone remodeling was subsequently evaluated. The average (±SD) follow-up time was 48.2 months (±29.30 months; range, 24 to 120 months). Of the original 134 implants placed, 5 implants (3.7%) failed. The implant survival rate was 96.3%. The average residual bone height was 3.46 mm (±0.91 mm) at baseline. The average height of the alveolar crest in the treated implant sites was 9.94 ± 2.29 mm. The radiographic bone gain was 6.48 ± 2.38 mm. The investigation suggests that this crestal drill approach can be a successful sinus lifting procedure in a severe atrophic maxilla with <5 mm of crestal bone height.

Type synthesis for 4-DOF parallel press mechanism using GF set theory

NASA Astrophysics Data System (ADS)

He, Jun; Gao, Feng; Meng, Xiangdun; Guo, Weizhong

2015-07-01

Parallel mechanisms is used in the large capacity servo press to avoid the over-constraint of the traditional redundant actuation. Currently, the researches mainly focus on the performance analysis for some specific parallel press mechanisms. However, the type synthesis and evaluation of parallel press mechanisms is seldom studied, especially for the four degrees of freedom(DOF) press mechanisms. The type synthesis of 4-DOF parallel press mechanisms is carried out based on the generalized function(GF) set theory. Five design criteria of 4-DOF parallel press mechanisms are firstly proposed. The general procedure of type synthesis of parallel press mechanisms is obtained, which includes number synthesis, symmetrical synthesis of constraint GF sets, decomposition of motion GF sets and design of limbs. Nine combinations of constraint GF sets of 4-DOF parallel press mechanisms, ten combinations of GF sets of active limbs, and eleven combinations of GF sets of passive limbs are synthesized. Thirty-eight kinds of press mechanisms are presented and then different structures of kinematic limbs are designed. Finally, the geometrical constraint complexity( GCC), kinematic pair complexity( KPC), and type complexity( TC) are proposed to evaluate the press types and the optimal press type is achieved. The general methodologies of type synthesis and evaluation for parallel press mechanism are suggested.

Design of on-board parallel computer on nano-satellite

NASA Astrophysics Data System (ADS)

You, Zheng; Tian, Hexiang; Yu, Shijie; Meng, Li

2007-11-01

This paper provides one scheme of the on-board parallel computer system designed for the Nano-satellite. Based on the development request that the Nano-satellite should have a small volume, low weight, low power cost, and intelligence, this scheme gets rid of the traditional one-computer system and dual-computer system with endeavor to improve the dependability, capability and intelligence simultaneously. According to the method of integration design, it employs the parallel computer system with shared memory as the main structure, connects the telemetric system, attitude control system, and the payload system by the intelligent bus, designs the management which can deal with the static tasks and dynamic task-scheduling, protect and recover the on-site status and so forth in light of the parallel algorithms, and establishes the fault diagnosis, restoration and system restructure mechanism. It accomplishes an on-board parallel computer system with high dependability, capability and intelligence, a flexible management on hardware resources, an excellent software system, and a high ability in extension, which satisfies with the conception and the tendency of the integration electronic design sufficiently.

Magnetic resonance imaging of the hand and wrist in a randomized, double-blind, multicenter, placebo-controlled trial of infliximab for rheumatoid arthritis: Comparison of dynamic contrast enhanced assessments with semi-quantitative scoring

PubMed Central

Baumgartner, Richard; Peterfy, Charles; Balanescu, Andra; Mirea, Gavrila; Harabagiu, Alexandru; Popa, Serghei; Cheng, Amy; Feng, Dai; Ashton, Edward; DiCarlo, Julie; Vallee, Marie-Helene; Dardzinski, Bernard J.

2017-01-01

The objective of this study was to compare the scope and the discriminative power of Dynamic Contrast Enhanced Magnetic Resonance Imaging (DCE-MRI) to those of semi-quantitative MRI scoring for evaluating treatments for rheumatoid arthritis (RA) in multicenter randomized clinical trials (RCTs). Sixty-one patients with active RA participated in a double-blind, parallel group, randomized, multicenter methodology study receiving infliximab or placebo through 14 weeks. The most symptomatic wrist and metacarpophalangeal joints (MCPs) were imaged using MRI. In addition to clinical assessments with DAS28(CRP), the severity of inflammation was measured as synovial leak of gadolinium based contrast agent (GBCA) using DCE-MRI (Ktrans, primary endpoint) at weeks 0, 2, 4, and 14. Two radiologists independently scored synovitis, osteitis and erosion using RA MRI Score (RAMRIS) and cartilage loss using a 9-point MRI scale (CARLOS). Infliximab showed greater decrease from baseline in DAS28(CRP), DCE-MRI Ktrans of wrist and MCP synovium, and RAMRIS synovitis and osteitis at all visits compared with placebo (p<0.001). Treatment effect sizes of infliximab therapy were similar for DAS28(CRP) (1.08; 90% CI (0.63–1.53)) and MRI inflammation endpoints: wrist Ktrans (1.00 (0.55–1.45)), RAMRIS synovitis (0.85 (0.38–1.28)) and RAMRIS osteitis (0.99 (0.52–1.43)). Damage measures of bone erosion (RAMRIS) and cartilage loss (CARLOS) were reduced with infliximab compared to with placebo at 14 weeks (p≤0.025). DCE-MRI and RAMRIS were equally sensitive and responsive to the anti-inflammatory effects of infliximab. RAMRIS and CARLOS showed suppression of erosion and cartilage loss, respectively, at 14 weeks. (ClinicalTrials.gov registration: NCT01313520) PMID:29236711

Magnetic resonance imaging of the hand and wrist in a randomized, double-blind, multicenter, placebo-controlled trial of infliximab for rheumatoid arthritis: Comparison of dynamic contrast enhanced assessments with semi-quantitative scoring.

PubMed

Beals, Chan; Baumgartner, Richard; Peterfy, Charles; Balanescu, Andra; Mirea, Gavrila; Harabagiu, Alexandru; Popa, Serghei; Cheng, Amy; Feng, Dai; Ashton, Edward; DiCarlo, Julie; Vallee, Marie-Helene; Dardzinski, Bernard J

2017-01-01

The objective of this study was to compare the scope and the discriminative power of Dynamic Contrast Enhanced Magnetic Resonance Imaging (DCE-MRI) to those of semi-quantitative MRI scoring for evaluating treatments for rheumatoid arthritis (RA) in multicenter randomized clinical trials (RCTs). Sixty-one patients with active RA participated in a double-blind, parallel group, randomized, multicenter methodology study receiving infliximab or placebo through 14 weeks. The most symptomatic wrist and metacarpophalangeal joints (MCPs) were imaged using MRI. In addition to clinical assessments with DAS28(CRP), the severity of inflammation was measured as synovial leak of gadolinium based contrast agent (GBCA) using DCE-MRI (Ktrans, primary endpoint) at weeks 0, 2, 4, and 14. Two radiologists independently scored synovitis, osteitis and erosion using RA MRI Score (RAMRIS) and cartilage loss using a 9-point MRI scale (CARLOS). Infliximab showed greater decrease from baseline in DAS28(CRP), DCE-MRI Ktrans of wrist and MCP synovium, and RAMRIS synovitis and osteitis at all visits compared with placebo (p<0.001). Treatment effect sizes of infliximab therapy were similar for DAS28(CRP) (1.08; 90% CI (0.63-1.53)) and MRI inflammation endpoints: wrist Ktrans (1.00 (0.55-1.45)), RAMRIS synovitis (0.85 (0.38-1.28)) and RAMRIS osteitis (0.99 (0.52-1.43)). Damage measures of bone erosion (RAMRIS) and cartilage loss (CARLOS) were reduced with infliximab compared to with placebo at 14 weeks (p≤0.025). DCE-MRI and RAMRIS were equally sensitive and responsive to the anti-inflammatory effects of infliximab. RAMRIS and CARLOS showed suppression of erosion and cartilage loss, respectively, at 14 weeks. (ClinicalTrials.gov registration: NCT01313520).

CFD Analysis and Design Optimization Using Parallel Computers

NASA Technical Reports Server (NTRS)

Martinelli, Luigi; Alonso, Juan Jose; Jameson, Antony; Reuther, James

1997-01-01

A versatile and efficient multi-block method is presented for the simulation of both steady and unsteady flow, as well as aerodynamic design optimization of complete aircraft configurations. The compressible Euler and Reynolds Averaged Navier-Stokes (RANS) equations are discretized using a high resolution scheme on body-fitted structured meshes. An efficient multigrid implicit scheme is implemented for time-accurate flow calculations. Optimum aerodynamic shape design is achieved at very low cost using an adjoint formulation. The method is implemented on parallel computing systems using the MPI message passing interface standard to ensure portability. The results demonstrate that, by combining highly efficient algorithms with parallel computing, it is possible to perform detailed steady and unsteady analysis as well as automatic design for complex configurations using the present generation of parallel computers.

ProperCAD: A portable object-oriented parallel environment for VLSI CAD

NASA Technical Reports Server (NTRS)

Ramkumar, Balkrishna; Banerjee, Prithviraj

1993-01-01

Most parallel algorithms for VLSI CAD proposed to date have one important drawback: they work efficiently only on machines that they were designed for. As a result, algorithms designed to date are dependent on the architecture for which they are developed and do not port easily to other parallel architectures. A new project under way to address this problem is described. A Portable object-oriented parallel environment for CAD algorithms (ProperCAD) is being developed. The objectives of this research are (1) to develop new parallel algorithms that run in a portable object-oriented environment (CAD algorithms using a general purpose platform for portable parallel programming called CARM is being developed and a C++ environment that is truly object-oriented and specialized for CAD applications is also being developed); and (2) to design the parallel algorithms around a good sequential algorithm with a well-defined parallel-sequential interface (permitting the parallel algorithm to benefit from future developments in sequential algorithms). One CAD application that has been implemented as part of the ProperCAD project, flat VLSI circuit extraction, is described. The algorithm, its implementation, and its performance on a range of parallel machines are discussed in detail. It currently runs on an Encore Multimax, a Sequent Symmetry, Intel iPSC/2 and i860 hypercubes, a NCUBE 2 hypercube, and a network of Sun Sparc workstations. Performance data for other applications that were developed are provided: namely test pattern generation for sequential circuits, parallel logic synthesis, and standard cell placement.

Charon Toolkit for Parallel, Implicit Structured-Grid Computations: Functional Design

NASA Technical Reports Server (NTRS)

VanderWijngaart, Rob F.; Kutler, Paul (Technical Monitor)

1997-01-01

In a previous report the design concepts of Charon were presented. Charon is a toolkit that aids engineers in developing scientific programs for structured-grid applications to be run on MIMD parallel computers. It constitutes an augmentation of the general-purpose MPI-based message-passing layer, and provides the user with a hierarchy of tools for rapid prototyping and validation of parallel programs, and subsequent piecemeal performance tuning. Here we describe the implementation of the domain decomposition tools used for creating data distributions across sets of processors. We also present the hierarchy of parallelization tools that allows smooth translation of legacy code (or a serial design) into a parallel program. Along with the actual tool descriptions, we will present the considerations that led to the particular design choices. Many of these are motivated by the requirement that Charon must be useful within the traditional computational environments of Fortran 77 and C. Only the Fortran 77 syntax will be presented in this report.

Treatment for premenstrual syndrome with Vitex agnus castus: A prospective, randomized, multi-center placebo controlled study in China.

PubMed

He, Zhong; Chen, Rong; Zhou, Yingfang; Geng, Li; Zhang, Zhenyu; Chen, Shuling; Yao, Yanjun; Lu, Junli; Lin, Shouqing

2009-05-20

To investigate the efficacy and safety of VAC BNO 1095 extract in Chinese women suffering from moderate to severe premenstrual syndrome (PMS). Prospective, double-blind, placebo controlled, parallel-group, multi-center clinical trial design was employed. After screening and preparation phase lasting three cycles, Eligible patients were randomly assigned into treatment or placebo groups and had treatment with VAC extract or placebo for up to three cycles. Efficacy was assessed using the Chinese version PMS-diary (PMSD) and PMTS. Two hundred and seventeen women were eligible to enter the treatment phase (TP) and were randomly assigned into the treatment group (108) or the placebo group (109), 208 provided the efficacy data (treatment 104, placebo 104), and 202 completed the treatment phase (treatment 101, placebo 101). The mean total PMSD score decreased from 29.23 at baseline (0 cycle) to 6.41 at the termination (3rd cycle) for the treatment group and from 28.14 at baseline (0 cycle) to 12.64 at the termination (3rd cycle) for the placebo group. The total PMSD score of 3rd cycle was significantly lower than the baseline in both groups (p<0.0001). The difference in the mean scores from the baseline to the 3rd cycle in the treatment group (22.71+/-10.33) was significantly lower than the difference in the placebo group (15.50+/-12.94, p<0.0001). Results of PMTS were similar, the total scores for PMTS were significantly lower between the two groups (p<0.01) and within each group (p<0.01). The score was decreased from 26.17+/-4.79 to 9.92+/-9.01 for the treatment group, and from 27.10+/-4.76 to 14.59+/-10.69 for the placebo group. A placebo effect of 50% was found in the present study. No serious adverse event (SAE) occurred in both groups. Vitex agnus castus (VAC BNO 1095 corresponding to 40mg herbal drug) is a safe, well tolerated and effective drug of the treatment for Chinese women with the moderate to severe PMS.

Supercomputing on massively parallel bit-serial architectures

NASA Technical Reports Server (NTRS)

Iobst, Ken

1985-01-01

Research on the Goodyear Massively Parallel Processor (MPP) suggests that high-level parallel languages are practical and can be designed with powerful new semantics that allow algorithms to be efficiently mapped to the real machines. For the MPP these semantics include parallel/associative array selection for both dense and sparse matrices, variable precision arithmetic to trade accuracy for speed, micro-pipelined train broadcast, and conditional branching at the processing element (PE) control unit level. The preliminary design of a FORTRAN-like parallel language for the MPP has been completed and is being used to write programs to perform sparse matrix array selection, min/max search, matrix multiplication, Gaussian elimination on single bit arrays and other generic algorithms. A description is given of the MPP design. Features of the system and its operation are illustrated in the form of charts and diagrams.

Process optimization using combinatorial design principles: parallel synthesis and design of experiment methods.

PubMed

Gooding, Owen W

2004-06-01

The use of parallel synthesis techniques with statistical design of experiment (DoE) methods is a powerful combination for the optimization of chemical processes. Advances in parallel synthesis equipment and easy to use software for statistical DoE have fueled a growing acceptance of these techniques in the pharmaceutical industry. As drug candidate structures become more complex at the same time that development timelines are compressed, these enabling technologies promise to become more important in the future.

Slice-selective RF pulses for in vivo B1+ inhomogeneity mitigation at 7 tesla using parallel RF excitation with a 16-element coil.

PubMed

Setsompop, Kawin; Alagappan, Vijayanand; Gagoski, Borjan; Witzel, Thomas; Polimeni, Jonathan; Potthast, Andreas; Hebrank, Franz; Fontius, Ulrich; Schmitt, Franz; Wald, Lawrence L; Adalsteinsson, Elfar

2008-12-01

Slice-selective RF waveforms that mitigate severe B1+ inhomogeneity at 7 Tesla using parallel excitation were designed and validated in a water phantom and human studies on six subjects using a 16-element degenerate stripline array coil driven with a butler matrix to utilize the eight most favorable birdcage modes. The parallel RF waveform design applied magnitude least-squares (MLS) criteria with an optimized k-space excitation trajectory to significantly improve profile uniformity compared to conventional least-squares (LS) designs. Parallel excitation RF pulses designed to excite a uniform in-plane flip angle (FA) with slice selection in the z-direction were demonstrated and compared with conventional sinc-pulse excitation and RF shimming. In all cases, the parallel RF excitation significantly mitigated the effects of inhomogeneous B1+ on the excitation FA. The optimized parallel RF pulses for human B1+ mitigation were only 67% longer than a conventional sinc-based excitation, but significantly outperformed RF shimming. For example the standard deviations (SDs) of the in-plane FA (averaged over six human studies) were 16.7% for conventional sinc excitation, 13.3% for RF shimming, and 7.6% for parallel excitation. This work demonstrates that excitations with parallel RF systems can provide slice selection with spatially uniform FAs at high field strengths with only a small pulse-duration penalty. (c) 2008 Wiley-Liss, Inc.

Integrated Task and Data Parallel Programming

NASA Technical Reports Server (NTRS)

Grimshaw, A. S.

1998-01-01

This research investigates the combination of task and data parallel language constructs within a single programming language. There are an number of applications that exhibit properties which would be well served by such an integrated language. Examples include global climate models, aircraft design problems, and multidisciplinary design optimization problems. Our approach incorporates data parallel language constructs into an existing, object oriented, task parallel language. The language will support creation and manipulation of parallel classes and objects of both types (task parallel and data parallel). Ultimately, the language will allow data parallel and task parallel classes to be used either as building blocks or managers of parallel objects of either type, thus allowing the development of single and multi-paradigm parallel applications. 1995 Research Accomplishments In February I presented a paper at Frontiers 1995 describing the design of the data parallel language subset. During the spring I wrote and defended my dissertation proposal. Since that time I have developed a runtime model for the language subset. I have begun implementing the model and hand-coding simple examples which demonstrate the language subset. I have identified an astrophysical fluid flow application which will validate the data parallel language subset. 1996 Research Agenda Milestones for the coming year include implementing a significant portion of the data parallel language subset over the Legion system. Using simple hand-coded methods, I plan to demonstrate (1) concurrent task and data parallel objects and (2) task parallel objects managing both task and data parallel objects. My next steps will focus on constructing a compiler and implementing the fluid flow application with the language. Concurrently, I will conduct a search for a real-world application exhibiting both task and data parallelism within the same program. Additional 1995 Activities During the fall I collaborated with Andrew Grimshaw and Adam Ferrari to write a book chapter which will be included in Parallel Processing in C++ edited by Gregory Wilson. I also finished two courses, Compilers and Advanced Compilers, in 1995. These courses complete my class requirements at the University of Virginia. I have only my dissertation research and defense to complete.

Social marketing-based communications to integrate and support the HEALTHY study intervention

USDA-ARS?s Scientific Manuscript database

The HEALTHY study was a randomized, controlled, multicenter, middle school-based, multifaceted intervention designed to reduce risk factors for the development of type 2 diabetes. The study randomized 42 middle schools to intervention or control, and followed students from the sixth to the eighth gr...

Multicenter Clinical Trial of Keratin Biomaterial for Peripheral Nerve Regeneration

DTIC Science & Technology

2012-10-01

Drug Evaluation Research (CDER), the Center for Biologics E valuation Research (CBER), and the Center for Devices and Radiological Health ( CDRH ) on May...Research (CBER) , and the Center for Devices and Radiological Health ( CDRH ) to clar ify the designation of the keratin hydrogel. During this m eeting

Variable-Complexity Multidisciplinary Optimization on Parallel Computers

NASA Technical Reports Server (NTRS)

Grossman, Bernard; Mason, William H.; Watson, Layne T.; Haftka, Raphael T.

1998-01-01

This report covers work conducted under grant NAG1-1562 for the NASA High Performance Computing and Communications Program (HPCCP) from December 7, 1993, to December 31, 1997. The objective of the research was to develop new multidisciplinary design optimization (MDO) techniques which exploit parallel computing to reduce the computational burden of aircraft MDO. The design of the High-Speed Civil Transport (HSCT) air-craft was selected as a test case to demonstrate the utility of our MDO methods. The three major tasks of this research grant included: development of parallel multipoint approximation methods for the aerodynamic design of the HSCT, use of parallel multipoint approximation methods for structural optimization of the HSCT, mathematical and algorithmic development including support in the integration of parallel computation for items (1) and (2). These tasks have been accomplished with the development of a response surface methodology that incorporates multi-fidelity models. For the aerodynamic design we were able to optimize with up to 20 design variables using hundreds of expensive Euler analyses together with thousands of inexpensive linear theory simulations. We have thereby demonstrated the application of CFD to a large aerodynamic design problem. For the predicting structural weight we were able to combine hundreds of structural optimizations of refined finite element models with thousands of optimizations based on coarse models. Computations have been carried out on the Intel Paragon with up to 128 nodes. The parallel computation allowed us to perform combined aerodynamic-structural optimization using state of the art models of a complex aircraft configurations.

Multicenter Clinical Trial of Keratin Biomaterial for Peripheral Nerve Regeneration

DTIC Science & Technology

2015-12-01

Radiological Health ( CDRH ) to clarify the designation of the hydrogel. As a result of this meeting, steps required for an IND for the keratin...the Center for Biologics Evaluation Research (CBER), and the Center for Devices and Radiological Health 8 ( CDRH ) to clarify the designation of the...application to the CDRH for a new product. This new product is the material that is produced in the validated manufacturing facility at KeraNetics. This

Design of a dataway processor for a parallel image signal processing system

NASA Astrophysics Data System (ADS)

Nomura, Mitsuru; Fujii, Tetsuro; Ono, Sadayasu

1995-04-01

Recently, demands for high-speed signal processing have been increasing especially in the field of image data compression, computer graphics, and medical imaging. To achieve sufficient power for real-time image processing, we have been developing parallel signal-processing systems. This paper describes a communication processor called 'dataway processor' designed for a new scalable parallel signal-processing system. The processor has six high-speed communication links (Dataways), a data-packet routing controller, a RISC CORE, and a DMA controller. Each communication link operates at 8-bit parallel in a full duplex mode at 50 MHz. Moreover, data routing, DMA, and CORE operations are processed in parallel. Therefore, sufficient throughput is available for high-speed digital video signals. The processor is designed in a top- down fashion using a CAD system called 'PARTHENON.' The hardware is fabricated using 0.5-micrometers CMOS technology, and its hardware is about 200 K gates.

Xyce parallel electronic simulator users guide, version 6.1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keiter, Eric R; Mei, Ting; Russo, Thomas V.

This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been designed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas; Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). This includes support for most popular parallel and serial computers; A differential-algebraic-equation (DAE) formulation, which better isolates the device model package from solver algorithms. This allows one to developmore » new types of analysis without requiring the implementation of analysis-specific device models; Device models that are specifically tailored to meet Sandia's needs, including some radiationaware devices (for Sandia users only); and Object-oriented code design and implementation using modern coding practices. Xyce is a parallel code in the most general sense of the phrase-a message passing parallel implementation-which allows it to run efficiently a wide range of computing platforms. These include serial, shared-memory and distributed-memory parallel platforms. Attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved as the number of processors grows.« less

Xyce parallel electronic simulator users' guide, Version 6.0.1.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keiter, Eric R; Mei, Ting; Russo, Thomas V.

This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been designed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). This includes support for most popular parallel and serial computers. A differential-algebraic-equation (DAE) formulation, which better isolates the device model package from solver algorithms. This allows one to developmore » new types of analysis without requiring the implementation of analysis-specific device models. Device models that are specifically tailored to meet Sandias needs, including some radiationaware devices (for Sandia users only). Object-oriented code design and implementation using modern coding practices. Xyce is a parallel code in the most general sense of the phrase a message passing parallel implementation which allows it to run efficiently a wide range of computing platforms. These include serial, shared-memory and distributed-memory parallel platforms. Attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved as the number of processors grows.« less

Xyce parallel electronic simulator users guide, version 6.0.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keiter, Eric R; Mei, Ting; Russo, Thomas V.

This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been designed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). This includes support for most popular parallel and serial computers. A differential-algebraic-equation (DAE) formulation, which better isolates the device model package from solver algorithms. This allows one to developmore » new types of analysis without requiring the implementation of analysis-specific device models. Device models that are specifically tailored to meet Sandias needs, including some radiationaware devices (for Sandia users only). Object-oriented code design and implementation using modern coding practices. Xyce is a parallel code in the most general sense of the phrase a message passing parallel implementation which allows it to run efficiently a wide range of computing platforms. These include serial, shared-memory and distributed-memory parallel platforms. Attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved as the number of processors grows.« less

A design methodology for portable software on parallel computers

NASA Technical Reports Server (NTRS)

Nicol, David M.; Miller, Keith W.; Chrisman, Dan A.

1993-01-01

This final report for research that was supported by grant number NAG-1-995 documents our progress in addressing two difficulties in parallel programming. The first difficulty is developing software that will execute quickly on a parallel computer. The second difficulty is transporting software between dissimilar parallel computers. In general, we expect that more hardware-specific information will be included in software designs for parallel computers than in designs for sequential computers. This inclusion is an instance of portability being sacrificed for high performance. New parallel computers are being introduced frequently. Trying to keep one's software on the current high performance hardware, a software developer almost continually faces yet another expensive software transportation. The problem of the proposed research is to create a design methodology that helps designers to more precisely control both portability and hardware-specific programming details. The proposed research emphasizes programming for scientific applications. We completed our study of the parallelizability of a subsystem of the NASA Earth Radiation Budget Experiment (ERBE) data processing system. This work is summarized in section two. A more detailed description is provided in Appendix A ('Programming Practices to Support Eventual Parallelism'). Mr. Chrisman, a graduate student, wrote and successfully defended a Ph.D. dissertation proposal which describes our research associated with the issues of software portability and high performance. The list of research tasks are specified in the proposal. The proposal 'A Design Methodology for Portable Software on Parallel Computers' is summarized in section three and is provided in its entirety in Appendix B. We are currently studying a proposed subsystem of the NASA Clouds and the Earth's Radiant Energy System (CERES) data processing system. This software is the proof-of-concept for the Ph.D. dissertation. We have implemented and measured the performance of a portion of this subsystem on the Intel iPSC/2 parallel computer. These results are provided in section four. Our future work is summarized in section five, our acknowledgements are stated in section six, and references for published papers associated with NAG-1-995 are provided in section seven.

Characterizing parallel file-access patterns on a large-scale multiprocessor

NASA Technical Reports Server (NTRS)

Purakayastha, A.; Ellis, Carla; Kotz, David; Nieuwejaar, Nils; Best, Michael L.

1995-01-01

High-performance parallel file systems are needed to satisfy tremendous I/O requirements of parallel scientific applications. The design of such high-performance parallel file systems depends on a comprehensive understanding of the expected workload, but so far there have been very few usage studies of multiprocessor file systems. This paper is part of the CHARISMA project, which intends to fill this void by measuring real file-system workloads on various production parallel machines. In particular, we present results from the CM-5 at the National Center for Supercomputing Applications. Our results are unique because we collect information about nearly every individual I/O request from the mix of jobs running on the machine. Analysis of the traces leads to various recommendations for parallel file-system design.

National Combustion Code Parallel Performance Enhancements

NASA Technical Reports Server (NTRS)

Quealy, Angela; Benyo, Theresa (Technical Monitor)

2002-01-01

The National Combustion Code (NCC) is being developed by an industry-government team for the design and analysis of combustion systems. The unstructured grid, reacting flow code uses a distributed memory, message passing model for its parallel implementation. The focus of the present effort has been to improve the performance of the NCC code to meet combustor designer requirements for model accuracy and analysis turnaround time. Improving the performance of this code contributes significantly to the overall reduction in time and cost of the combustor design cycle. This report describes recent parallel processing modifications to NCC that have improved the parallel scalability of the code, enabling a two hour turnaround for a 1.3 million element fully reacting combustion simulation on an SGI Origin 2000.

Frontal fibrosing alopecia: a multicenter review of 355 patients.

PubMed

Vañó-Galván, Sergio; Molina-Ruiz, Ana M; Serrano-Falcón, Cristina; Arias-Santiago, Salvador; Rodrigues-Barata, Ana R; Garnacho-Saucedo, Gloria; Martorell-Calatayud, Antonio; Fernández-Crehuet, Pablo; Grimalt, Ramón; Aranegui, Beatriz; Grillo, Emiliano; Diaz-Ley, Blanca; Salido, Rafael; Pérez-Gala, Sivia; Serrano, Salvio; Moreno, Jose Carlos; Jaén, Pedro; Camacho, Francisco M

2014-04-01

To our knowledge, there are no large multicenter studies concerning frontal fibrosing alopecia (FFA) that could give clues about its pathogenesis and best treatment. We sought to describe the epidemiology, comorbidities, clinical presentation, diagnostic findings, and therapeutic choices in a large series of patients with FFA. This retrospective multicenter study included patients given the diagnosis of FFA. Clinical severity was classified based on the recession of the frontotemporal hairline. In all, 355 patients (343 women [49 premenopausal] and 12 men) with a mean age of 61 years (range 23-86) were included. Early menopause was detected in 49 patients (14%), whereas 46 (13%) had undergone hysterectomy. Severe FFA was observed in 131 patients (37%). Independent factors associated with severe FFA after multivariate analysis were: eyelash loss, facial papules, and body hair involvement. Eyebrow loss as the initial clinical presentation was associated with mild forms. Antiandrogens such as finasteride and dutasteride were used in 111 patients (31%), with improvement in 52 (47%) and stabilization in 59 (53%). The retrospective design is a limitation. Eyelash loss, facial papules, and body hair involvement were associated with severe FFA. Antiandrogens were the most useful treatment. Copyright © 2014 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Subject-driven titration of biphasic insulin aspart 30 twice daily is non-inferior to investigator-driven titration in Chinese patients with type 2 diabetes inadequately controlled with premixed human insulin: A randomized, open-label, parallel-group, multicenter trial.

PubMed

Yang, Wenying; Zhu, Lvyun; Meng, Bangzhu; Liu, Yu; Wang, Wenhui; Ye, Shandong; Sun, Li; Miao, Heng; Guo, Lian; Wang, Zhanjian; Lv, Xiaofeng; Li, Quanmin; Ji, Qiuhe; Zhao, Weigang; Yang, Gangyi

2016-01-01

The present study was to compare the efficacy and safety of subject-driven and investigator-driven titration of biphasic insulin aspart 30 (BIAsp 30) twice daily (BID). In this 20-week, randomized, open-label, two-group parallel, multicenter trial, Chinese patients with type 2 diabetes inadequately controlled by premixed/self-mixed human insulin were randomized 1:1 to subject-driven or investigator-driven titration of BIAsp 30 BID, in combination with metformin and/or α-glucosidase inhibitors. Dose adjustment was decided by patients in the subject-driven group after training, and by investigators in the investigator-driven group. Eligible adults (n = 344) were randomized in the study. The estimated glycated hemoglobin (HbA1c) reduction was 14.5 mmol/mol (1.33%) in the subject-driven group and 14.3 mmol/mol (1.31%) in the investigator-driven group. Non-inferiority of subject-titration vs investigator-titration in reducing HbA1c was confirmed, with estimated treatment difference -0.26 mmol/mol (95% confidence interval -2.05, 1.53) (-0.02%, 95% confidence interval -0.19, 0.14). Fasting plasma glucose, postprandial glucose increment and self-measured plasma glucose were improved in both groups without statistically significant differences. One severe hypoglycemic event was experienced by one subject in each group. A similar rate of nocturnal hypoglycemia (events/patient-year) was reported in the subject-driven (1.10) and investigator-driven (1.32) groups. There were 64.5 and 58.1% patients achieving HbA1c <53.0 mmol/mol (7.0%), and 51.2 and 45.9% patients achieving the HbA1c target without confirmed hypoglycemia throughout the trial in the subject-driven and investigator-driven groups, respectively. Subject-titration of BIAsp 30 BID was as efficacious and well-tolerated as investigator-titration. The present study supported patients to self-titrate BIAsp 30 BID under physicians' supervision.

Multicenter, double-blind, randomized, placebo-controlled, parallel-group study of the efficacy, safety, and tolerability of THC:CBD extract and THC extract in patients with intractable cancer-related pain.

PubMed

Johnson, Jeremy R; Burnell-Nugent, Mary; Lossignol, Dominique; Ganae-Motan, Elena Doina; Potts, Richard; Fallon, Marie T

2010-02-01

This study compared the efficacy of a tetrahydrocannabinol:cannabidiol (THC:CBD) extract, a nonopioid analgesic endocannabinoid system modulator, and a THC extract, with placebo, in relieving pain in patients with advanced cancer. In total, 177 patients with cancer pain, who experienced inadequate analgesia despite chronic opioid dosing, entered a two-week, multicenter, double-blind, randomized, placebo-controlled, parallel-group trial. Patients were randomized to THC:CBD extract (n = 60), THC extract (n = 58), or placebo (n = 59). The primary analysis of change from baseline in mean pain Numerical Rating Scale (NRS) score was statistically significantly in favor of THC:CBD compared with placebo (improvement of -1.37 vs. -0.69), whereas the THC group showed a nonsignificant change (-1.01 vs. -0.69). Twice as many patients taking THC:CBD showed a reduction of more than 30% from baseline pain NRS score when compared with placebo (23 [43%] vs. 12 [21%]). The associated odds ratio was statistically significant, whereas the number of THC group responders was similar to placebo (12 [23%] vs. 12 [21%]) and did not reach statistical significance. There was no change from baseline in median dose of opioid background medication or mean number of doses of breakthrough medication across treatment groups. No significant group differences were found in the NRS sleep quality or nausea scores or the pain control assessment. However, the results from the European Organisation for Research and Treatment of Cancer Quality of Life Cancer Questionnaire showed a worsening in nausea and vomiting with THC:CBD compared with placebo (P = 0.02), whereas THC had no difference (P = 1.0). Most drug-related adverse events were mild/moderate in severity. This study shows that THC:CBD extract is efficacious for relief of pain in patients with advanced cancer pain not fully relieved by strong opioids. Copyright 2010 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.

SESOTHO trial ("Switch Either near Suppression Or THOusand") - switch to second-line versus WHO-guided standard of care for unsuppressed patients on first-line ART with viremia below 1000 copies/mL: protocol of a multicenter, parallel-group, open-label, randomized clinical trial in Lesotho, Southern Africa.

PubMed

Amstutz, Alain; Nsakala, Bienvenu Lengo; Vanobberghen, Fiona; Muhairwe, Josephine; Glass, Tracy Renée; Achieng, Beatrice; Sepeka, Mamorena; Tlali, Katleho; Sao, Lebohang; Thin, Kyaw; Klimkait, Thomas; Battegay, Manuel; Labhardt, Niklaus Daniel

2018-02-12

The World Health Organization (WHO) recommends viral load (VL) measurement as the preferred monitoring strategy for HIV-infected individuals on antiretroviral therapy (ART) in resource-limited settings. The new WHO guidelines 2016 continue to define virologic failure as two consecutive VL ≥1000 copies/mL (at least 3 months apart) despite good adherence, triggering switch to second-line therapy. However, the threshold of 1000 copies/mL for defining virologic failure is based on low-quality evidence. Observational studies have shown that individuals with low-level viremia (measurable but below 1000 copies/mL) are at increased risk for accumulation of resistance mutations and subsequent virologic failure. The SESOTHO trial assesses a lower threshold for switch to second-line ART in patients with sustained unsuppressed VL. In this multicenter, parallel-group, open-label, randomized controlled trial conducted in Lesotho, patients on first-line ART with two consecutive unsuppressed VL measurements ≥100 copies/mL, where the second VL is between 100 and 999 copies/mL, will either be switched to second-line ART immediately (intervention group) or not be switched (standard of care, according to WHO guidelines). The primary endpoint is viral resuppression (VL < 50 copies/mL) 9 months after randomization. We will enrol 80 patients, giving us 90% power to detect a difference of 35% in viral resuppression between the groups (assuming two-sided 5% alpha error). For our primary analysis, we will use a modified intention-to-treat set, with those lost to care, death, or crossed over considered failure to resuppress, and using logistic regression models adjusted for the prespecified stratification variables. The SESOTHO trial challenges the current WHO guidelines, assessing an alternative, lower VL threshold for patients with unsuppressed VL on first-line ART. This trial will provide data to inform future WHO guidelines on VL thresholds to recommend switch to second-line ART. ClinicalTrials.gov ( NCT03088241 ), registered May 05, 2017.

A Parallel Genetic Algorithm for Automated Electronic Circuit Design

NASA Technical Reports Server (NTRS)

Lohn, Jason D.; Colombano, Silvano P.; Haith, Gary L.; Stassinopoulos, Dimitris; Norvig, Peter (Technical Monitor)

2000-01-01

We describe a parallel genetic algorithm (GA) that automatically generates circuit designs using evolutionary search. A circuit-construction programming language is introduced and we show how evolution can generate practical analog circuit designs. Our system allows circuit size (number of devices), circuit topology, and device values to be evolved. We present experimental results as applied to analog filter and amplifier design tasks.

Coordination and management of multicenter clinical studies in trauma: Experience from the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) Study.

PubMed

Rahbar, Mohammad H; Fox, Erin E; del Junco, Deborah J; Cotton, Bryan A; Podbielski, Jeanette M; Matijevic, Nena; Cohen, Mitchell J; Schreiber, Martin A; Zhang, Jiajie; Mirhaji, Parsa; Duran, Sarah J; Reynolds, Robert J; Benjamin-Garner, Ruby; Holcomb, John B

2012-04-01

Early death due to hemorrhage is a major consequence of traumatic injury. Transfusion practices differ among hospitals and it is unknown which transfusion practices improve survival. This report describes the experience of the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) Study Data Coordination Center in designing and coordinating a study to examine transfusion practices at ten Level 1 trauma centers in the US. PROMMTT was a multisite prospective observational study of severely injured transfused trauma patients. The clinical sites collected real-time information on the timing and amounts of blood product infusions as well as colloids and crystalloids, vital signs, initial diagnostic and clinical laboratory tests, life saving interventions and other clinical care data. Between July 2009 and October 2010, PROMMTT screened 12,561 trauma admissions and enrolled 1245 patients who received one or more blood transfusions within 6h of Emergency Department (ED) admission. A total of 297 massive transfusions were observed over the course of the study at a combined rate of 5.0 massive transfusion patients/week. PROMMTT is the first multisite study to collect real-time prospective data on trauma patients requiring transfusion. Support from the Department of Defense and collaborative expertise from the ten participating centers helped to demonstrate the feasibility of prospective trauma transfusion studies. The observational data collected from this study will be an invaluable resource for research in trauma surgery and it will guide the design and conduct of future randomized trials. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Coordination and management of multicenter clinical studies in trauma: Experience from the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) Study

PubMed Central

Rahbar, Mohammad H.; Fox, Erin E.; del Junco, Deborah J.; Cotton, Bryan A.; Podbielski, Jeanette M.; Matijevic, Nena; Cohen, Mitchell J.; Schreiber, Martin A.; Zhang, Jiajie; Mirhaji, Parsa; Duran, Sarah; Reynolds, Robert J.; Benjamin-Garner, Ruby; Holcomb, John B.

2011-01-01

Aim Early death due to hemorrhage is a major consequence of traumatic injury. Transfusion practices differ among hospitals and it is unknown which transfusion practices improve survival. This report describes the experience of the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) Study Data Coordination Center in designing and coordinating a study to examine transfusion practices at ten Level 1 trauma centers in the U.S. Methods PROMMTT was a multisite prospective observational study of severely injured transfused trauma patients. The clinical sites collected real-time information on the timing and amounts of blood product infusions as well as colloids and crystalloids, vital signs, initial diagnostic and clinical laboratory tests, life saving interventions and other clinical care data. Results Between July 2009 and October 2010, PROMMTT screened 12,561 trauma admissions and enrolled 1,245 patients who received one or more blood transfusions within 6 hours of ED admission. A total of 297 massive transfusions were observed over the course of the study at a combined rate of 5.0 massive transfusion patients/week. Conclusion PROMMTT is the first multisite study to collect real-time prospective data on trauma patients requiring transfusion. Support from the Department of Defense and collaborative expertise from the ten participating centers helped to demonstrate the feasibility of prospective trauma transfusion studies. The observational data collected from this study will be an invaluable resource for research in trauma surgery and it will guide the design and conduct of future randomized trials. PMID:22001613

ARTS III/Parallel Processor Design Study

DOT National Transportation Integrated Search

1975-04-01

It was the purpose of this design study to investigate the feasibility, suitability, and cost-effectiveness of augmenting the ARTS III failsafe/failsoft multiprocessor system with a form of parallel processor to accomodate a large growth in air traff...

Multidisciplinary Optimization Methods for Aircraft Preliminary Design

NASA Technical Reports Server (NTRS)

Kroo, Ilan; Altus, Steve; Braun, Robert; Gage, Peter; Sobieski, Ian

1994-01-01

This paper describes a research program aimed at improved methods for multidisciplinary design and optimization of large-scale aeronautical systems. The research involves new approaches to system decomposition, interdisciplinary communication, and methods of exploiting coarse-grained parallelism for analysis and optimization. A new architecture, that involves a tight coupling between optimization and analysis, is intended to improve efficiency while simplifying the structure of multidisciplinary, computation-intensive design problems involving many analysis disciplines and perhaps hundreds of design variables. Work in two areas is described here: system decomposition using compatibility constraints to simplify the analysis structure and take advantage of coarse-grained parallelism; and collaborative optimization, a decomposition of the optimization process to permit parallel design and to simplify interdisciplinary communication requirements.

Xyce parallel electronic simulator : users' guide.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mei, Ting; Rankin, Eric Lamont; Thornquist, Heidi K.

2011-05-01

This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been designed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: (1) Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). Note that this includes support for most popular parallel and serial computers; (2) Improved performance for all numerical kernels (e.g., time integrator, nonlinear and linear solvers) through state-of-the-artmore » algorithms and novel techniques. (3) Device models which are specifically tailored to meet Sandia's needs, including some radiation-aware devices (for Sandia users only); and (4) Object-oriented code design and implementation using modern coding practices that ensure that the Xyce Parallel Electronic Simulator will be maintainable and extensible far into the future. Xyce is a parallel code in the most general sense of the phrase - a message passing parallel implementation - which allows it to run efficiently on the widest possible number of computing platforms. These include serial, shared-memory and distributed-memory parallel as well as heterogeneous platforms. Careful attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved as the number of processors grows. The development of Xyce provides a platform for computational research and development aimed specifically at the needs of the Laboratory. With Xyce, Sandia has an 'in-house' capability with which both new electrical (e.g., device model development) and algorithmic (e.g., faster time-integration methods, parallel solver algorithms) research and development can be performed. As a result, Xyce is a unique electrical simulation capability, designed to meet the unique needs of the laboratory.« less

Hormonal regulators of muscle and metabolism in aging (HORMA): Design and conduct of a complex, double-masked, multicenter trial

USDA-ARS?s Scientific Manuscript database

BACKGROUND: Older persons often lose muscle mass, strength, and physical function. This report describes the challenges of conducting a complex clinical investigation assessing the effects of anabolic hormones on body composition, physical function, and metabolism during aging. METHODS: HORMA is a m...

Effect of structured physical activity on prevention of serious fall injuries in adults aged 70-89: randomized clinical trial (LIFE Study)

USDA-ARS?s Scientific Manuscript database

OBJECTIVE: To test whether a long term, structured physical activity program compared with a health education program reduces the risk of serious fall injuries among sedentary older people with functional limitations. DESIGN: Multicenter, single blinded randomized trial (Lifestyle Interventions and ...

The Treatment for Adolescents with Depression Study (TADS): Demographic and Clinical Characteristics

ERIC Educational Resources Information Center

n/a; n/a

2005-01-01

Objective: The Treatment for Adolescents With Depression Study is a multicenter, randomized clinical trial sponsored by the NIMH. This study is designed to evaluate the short- and long-term effectiveness of four treatments for adolescents with major depressive disorder: fluoxetine, cognitive-behavioral therapy, their combination, and, acutely,…

Transcatheter Mitral Valve Replacement for Native and Failed Bioprosthetic Mitral Valves

PubMed Central

Sarkar, Kunal; Reardon, Michael J.; Little, Stephen H.; Barker, Colin M.; Kleiman, Neal S.

2017-01-01

Transcatheter mitral valve replacement (TMVR) is a novel approach for treatment of severe mitral regurgitation. A number of TMVR devices are currently undergoing feasibility trials using both transseptal and transapical routes for device delivery. Overall experience worldwide is limited to fewer than 200 cases. At present, the 30-day mortality exceeds 30% and is attributable to both patient- and device-related factors. TMVR has been successfully used to treat patients with degenerative mitral stenosis (DMS) as well as failed mitral bioprosthesis and mitral repair using transcatheter mitral valve-in-valve (TMViV)/valve-in-ring (ViR) repair. These patients are currently treated with devices designed for transcatheter aortic valve replacement. Multicenter registries have been initiated to collect outcomes data on patients currently undergoing TMViV/ViR and TMVR for DMS and have confirmed the feasibility of TMVR in these patients. However, the high periprocedural and 30-day event rates underscore the need for further improvements in device design and multicenter randomized studies to delineate the role of these technologies in patients with mitral valve disease. PMID:29743999

Parallel Processing at the High School Level.

ERIC Educational Resources Information Center

Sheary, Kathryn Anne

This study investigated the ability of high school students to cognitively understand and implement parallel processing. Data indicates that most parallel processing is being taught at the university level. Instructional modules on C, Linux, and the parallel processing language, P4, were designed to show that high school students are highly…

Multicenter neonatal databases: Trends in research uses.

PubMed

Creel, Liza M; Gregory, Sean; McNeal, Catherine J; Beeram, Madhava R; Krauss, David R

2017-01-13

In the US, approximately 12.7% of all live births are preterm, 8.2% of live births were low birth weight (LBW), and 1.5% are very low birth weight (VLBW). Although technological advances have improved mortality rates among preterm and LBW infants, improving overall rates of prematurity and LBW remains a national priority. Monitoring short- and long-term outcomes is critical for advancing medical treatment and minimizing morbidities associated with prematurity or LBW; however, studying these infants can be challenging. Several large, multi-center neonatal databases have been developed to improve research and quality improvement of treatments for and outcomes of premature and LBW infants. The purpose of this systematic review was to describe three multi-center neonatal databases. We conducted a literature search using PubMed and Google Scholar over the period 1990 to August 2014. Studies were included in our review if one of the databases was used as a primary source of data or comparison. Included studies were categorized by year of publication; study design employed, and research focus. A total of 343 studies published between 1991 and 2014 were included. Studies of premature and LBW infants using these databases have increased over time, and provide evidence for both neonatology and community-based pediatric practice. Research into treatment and outcomes of premature and LBW infants is expanding, partially due to the availability of large, multicenter databases. The consistency of clinical conditions and neonatal outcomes studied since 1990 demonstrates that there are dedicated research agendas and resources that allow for long-term, and potentially replicable, studies within this population.

Architecture design of a generic centralized adjudication module integrated in a web-based clinical trial management system.

PubMed

Zhao, Wenle; Pauls, Keith

2016-04-01

Centralized outcome adjudication has been used widely in multicenter clinical trials in order to prevent potential biases and to reduce variations in important safety and efficacy outcome assessments. Adjudication procedures could vary significantly among different studies. In practice, the coordination of outcome adjudication procedures in many multicenter clinical trials remains as a manual process with low efficiency and high risk of delay. Motivated by the demands from two large clinical trial networks, a generic outcome adjudication module has been developed by the network's data management center within a homegrown clinical trial management system. In this article, the system design strategy and database structure are presented. A generic database model was created to transfer different adjudication procedures into a unified set of sequential adjudication steps. Each adjudication step was defined by one activate condition, one lock condition, one to five categorical data items to capture adjudication results, and one free text field for general comments. Based on this model, a generic outcome adjudication user interface and a generic data processing program were developed within a homegrown clinical trial management system to provide automated coordination of outcome adjudication. By the end of 2014, this generic outcome adjudication module had been implemented in 10 multicenter trials. A total of 29 adjudication procedures were defined with the number of adjudication steps varying from 1 to 7. The implementation of a new adjudication procedure in this generic module took an experienced programmer 1 or 2 days. A total of 7336 outcome events had been adjudicated and 16,235 adjudication step activities had been recorded. In a multicenter trial, 1144 safety outcome event submissions went through a three-step adjudication procedure and reported a median of 3.95 days from safety event case report form submission to adjudication completion. In another trial, 277 clinical outcome events were adjudicated by a six-step procedure and took a median of 23.84 days from outcome event case report form submission to adjudication procedure completion. A generic outcome adjudication module integrated in the clinical trial management system made the automated coordination of efficacy and safety outcome adjudication a reality. © The Author(s) 2015.

Fringe Capacitance of a Parallel-Plate Capacitor.

ERIC Educational Resources Information Center

Hale, D. P.

1978-01-01

Describes an experiment designed to measure the forces between charged parallel plates, and determines the relationship among the effective electrode area, the measured capacitance values, and the electrode spacing of a parallel plate capacitor. (GA)

Perioperative strategy in colonic surgery; LAparoscopy and/or FAst track multimodal management versus standard care (LAFA trial)

PubMed Central

Wind, Jan; Hofland, Jan; Preckel, Benedikt; Hollmann, Markus W; Bossuyt, Patrick MM; Gouma, Dirk J; van Berge Henegouwen, Mark I; Fuhring, Jan Willem; Dejong, Cornelis HC; van Dam, Ronald M; Cuesta, Miguel A; Noordhuis, Astrid; de Jong, Dick; van Zalingen, Edith; Engel, Alexander F; Goei, T Hauwy; de Stoppelaar, I Erica; van Tets, Willem F; van Wagensveld, Bart A; Swart, Annemiek; van den Elsen, Maarten JLJ; Gerhards, Michael F; de Wit, Laurens Th; Siepel, Muriel AM; van Geloven, Anna AW; Juttmann, Jan-Willem; Clevers, Wilfred; Bemelman, Willem A

2006-01-01

Background Recent developments in large bowel surgery are the introduction of laparoscopic surgery and the implementation of multimodal fast track recovery programs. Both focus on a faster recovery and shorter hospital stay. The randomized controlled multicenter LAFA-trial (LAparoscopy and/or FAst track multimodal management versus standard care) was conceived to determine whether laparoscopic surgery, fast track perioperative care or a combination of both is to be preferred over open surgery with standard care in patients having segmental colectomy for malignant disease. Methods/design The LAFA-trial is a double blinded, multicenter trial with a 2 × 2 balanced factorial design. Patients eligible for segmental colectomy for malignant colorectal disease i.e. right and left colectomy and anterior resection will be randomized to either open or laparoscopic colectomy, and to either standard care or the fast track program. This factorial design produces four treatment groups; open colectomy with standard care (a), open colectomy with fast track program (b), laparoscopic colectomy with standard care (c), and laparoscopic surgery with fast track program (d). Primary outcome parameter is postoperative hospital length of stay including readmission within 30 days. Secondary outcome parameters are quality of life two and four weeks after surgery, overall hospital costs, morbidity, patient satisfaction and readmission rate. Based on a mean postoperative hospital stay of 9 +/- 2.5 days a group size of 400 patients (100 each arm) can reliably detect a minimum difference of 1 day between the four arms (alfa = 0.95, beta = 0.8). With 100 patients in each arm a difference of 10% in subscales of the Short Form 36 (SF-36) questionnaire and social functioning can be detected. Discussion The LAFA-trial is a randomized controlled multicenter trial that will provide evidence on the merits of fast track perioperative care and laparoscopic colorectal surgery in patients having segmental colectomy for malignant disease. PMID:17134506

A Multicenter Approach Evaluating the Impact of Vitamin E-Blended Polyethylene in Cementless Total Hip Replacement

PubMed Central

Jäger, Marcus; van Wasen, Andrea; Warwas, Sebastian; Landgraeber, Stefan; Haversath, Marcel; Group, VITAS

2014-01-01

Since polyethylene is one of the most frequently used biomaterials as a liner in total hip arthroplasty, strong efforts have been made to improve design and material properties over the last 50 years. Antioxidants seems to be a promising alternative to further increase durability and reduce polyethylene wear in long term. As of yet, only in vitro results are available. While they are promising, there is yet no clinical evidence that the new material shows these advantages in vivo. To answer the question if vitamin-E enhanced ultra-high molecular weight polyethylene (UHMWPE) is able to improve long-term survivorship of cementless total hip arthroplasty we initiated a randomized long-term multicenter trial. Designed as a superiority study, the oxidation index assessed in retrieval analyses of explanted liners was chosen as primary parameter. Radiographic results (wear rate, osteolysis, radiolucency) and functional outcome (Harris Hip Scores, University of California-Los Angeles, Hip Disability and Osteoarthritis Outcome Score, Visual Analogue Scale) will serve as secondary parameters. Patients with the indication for a cementless total hip arthroplasty will be asked to participate in the study and will be randomized to either receive a standard hip replacement with a highly cross-linked UHMWPE-X liner or a highly cross-linked vitamin-E supplemented UHMWPE-XE liner. The follow-up will be 15 years, with evaluation after 5, 10 and 15 years. The controlled randomized study has been designed to determine if Vitamin-E supplemented highly cross-linked polyethylene liners are superior to standard XLPE liners in cementless total hip arthroplasty. While several studies have been started to evaluate the influence of vitamin-E, most of them evaluate wear rates and functional results. The approach used for this multicenter study, to analyze the oxidation status of retrieved implants, should make it possible to directly evaluate the ageing process and development of the implant material itself over a time period of 15 years. PMID:25002933

Multicenter clinical study on the treatment of children's tic disorder with Qufeng Zhidong Recipe.

PubMed

Wu, Min; Xiao, Guang-hua; Yao, Min; Zhang, Jian-ming; Zhang, Xin; Zhou, Ya-bing; Zhang, Jing-yan; Wang, Shu-xia; Ma, Bo; Chen, Yan-ping

2009-08-01

To assess the effect and adverse reaction of Qufeng Zhidong Recipe (QZR) in treating children's tic disorder (TD). With multicenter randomized parallel open-controlled method adopted, the patients enrolled were assigned to two groups, 41 cases in the Chinese medicine (CM) group and 40 in the Western medicine (WM) group. They were treated by QZR and haloperidol plus trihexyphenidyl respectively for 12 weeks as one course. In total, two courses of treatment were given. The curative effect and adverse reactions were evaluated by scoring with Yale Global Tic Severity Scale (YGTSS), Traditional Chinese Medicine Syndrome Scale (TCMSS), and Treatment Emergent Symptom Scale (TESS), as well as results of laboratory examinations. After one course of treatment, the markedly effective rate in the CM and the WM group was 14.6% and 17.5%, respectively, and the total effective rate 43.9% and 47.5%, respectively, which showed insignificant difference between groups (P>0.05). However, after two courses of treatment, markedly effective rate in them was 73.2% and 7.5%, and the total effective rate was 100.0% and 57.5%, both showing significant differences between groups (P<0.05). Besides, the adverse reactions occurred in the CM group was less than that in the WM group obviously. QZR has definite curative effect with no apparent adverse reaction in treating TD, and it can obviously improve the symptoms and signs and upgrade the quality of life and learning capacities in such patients.

A Multicenter, Randomized, Controlled Trial of Osteopathic Manipulative Treatment on Preterms

PubMed Central

Cerritelli, Francesco; Pizzolorusso, Gianfranco; Renzetti, Cinzia; Cozzolino, Vincenzo; D’Orazio, Marianna; Lupacchini, Mariacristina; Marinelli, Benedetta; Accorsi, Alessandro; Lucci, Chiara; Lancellotti, Jenny; Ballabio, Silvia; Castelli, Carola; Molteni, Daniela; Besana, Roberto; Tubaldi, Lucia; Perri, Francesco Paolo; Fusilli, Paola; D’Incecco, Carmine; Barlafante, Gina

2015-01-01

Background Despite some preliminary evidence, it is still largely unknown whether osteopathic manipulative treatment improves preterm clinical outcomes. Materials and Methods The present multi-center randomized single blind parallel group clinical trial enrolled newborns who met the criteria for gestational age between 29 and 37 weeks, without any congenital complication from 3 different public neonatal intensive care units. Preterm infants were randomly assigned to usual prenatal care (control group) or osteopathic manipulative treatment (study group). The primary outcome was the mean difference in length of hospital stay between groups. Results A total of 695 newborns were randomly assigned to either the study group (n= 352) or the control group (n=343). A statistical significant difference was observed between the two groups for the primary outcome (13.8 and 17.5 days for the study and control group respectively, p<0.001, effect size: 0.31). Multivariate analysis showed a reduction of the length of stay of 3.9 days (95% CI -5.5 to -2.3, p<0.001). Furthermore, there were significant reductions with treatment as compared to usual care in cost (difference between study and control group: 1,586.01€; 95% CI 1,087.18 to 6,277.28; p<0.001) but not in daily weight gain. There were no complications associated to the intervention. Conclusions Osteopathic treatment reduced significantly the number of days of hospitalization and is cost-effective on a large cohort of preterm infants. PMID:25974071

Pursestring closure of the stoma site leads to fewer wound infections: results from a multicenter randomized controlled trial.

PubMed

Lee, Janet T; Marquez, Thao T; Clerc, Daniel; Gie, Olivier; Demartines, Nicolas; Madoff, Robert D; Rothenberger, David A; Christoforidis, Dimitrios

2014-11-01

Surgical site infection after stoma reversal is common. The optimal skin closure technique after stoma reversal has been widely debated in the literature. We hypothesized that pursestring near-complete closure of the stoma site would lead to fewer surgical site infections compared with conventional primary closure. This study was a parallel prospective multicenter randomized controlled trial. This study was conducted at 2 university medical centers. Patients (N = 122) presenting for elective colostomy or ileostomy reversal were selected. Pursestring versus conventional primary closure of stoma sites were compared. Stoma site surgical site infection within 30 days of surgery, overall surgical site infection, delayed healing (open wound for >30 days), time to wound epithelialization, and patient satisfaction were the primary outcomes measured. The pursestring group had a significantly lower stoma site infection rate (2% vs 15%, p = 0.01). There was no difference in delayed healing or patient satisfaction between groups. Time to epithelialization was measured in only 51 patients but was significantly longer in the pursestring group (34.6 ± 20 days vs 24.1 ± 17 days, p = 0.02). This study was limited by the variability in procedures and surgeons, the limited follow-up after 30 days, and the inability to perform blinding. Pursestring closure after stoma reversal has a lower risk of stoma site surgical site infection than conventional primary closure, although wounds may take longer to heal with the use of this approach. NCT01713452 (www.clinicaltrials.gov).

Effectiveness of a smartphone application for improving healthy lifestyles, a randomized clinical trial (EVIDENT II): study protocol.

PubMed

Recio-Rodríguez, José I; Martín-Cantera, Carlos; González-Viejo, Natividad; Gómez-Arranz, Amparo; Arietaleanizbeascoa, Maria S; Schmolling-Guinovart, Yolanda; Maderuelo-Fernandez, Jose A; Pérez-Arechaederra, Diana; Rodriguez-Sanchez, Emiliano; Gómez-Marcos, Manuel A; García-Ortiz, Luis

2014-03-15

New technologies could facilitate changes in lifestyle and improve public health. However, no large randomized, controlled studies providing scientific evidence of the benefits of their use have been made. The aims of this study are to develop and validate a smartphone application, and to evaluate the effect of adding this tool to a standardized intervention designed to improve adherence to the Mediterranean diet and to physical activity. An evaluation is also made of the effect of modifying habits upon vascular structure and function, and therefore on arterial aging. A randomized, double-blind, multicenter, parallel group clinical trial will be carried out. A total of 1215 subjects under 70 years of age from the EVIDENT trial will be included. Counseling common to both groups (control and intervention) will be provided on adaptation to the Mediterranean diet and on physical activity. The intervention group moreover will receive training on the use of a smartphone application designed to promote a healthy diet and increased physical activity, and will use the application for three months. The main study endpoints will be the changes in physical activity, assessed by accelerometer and the 7-day Physical Activity Recall (PAR) interview, and adaptation to the Mediterranean diet, as evaluated by an adherence questionnaire and a food frequency questionnaire (FFQ). Evaluation also will be made of vascular structure and function based on central arterial pressure, the radial augmentation index, pulse velocity, the cardio-ankle vascular index, and carotid intima-media thickness. Confirmation that the new technologies are useful for promoting healthier lifestyles and that their effects are beneficial in terms of arterial aging will have important clinical implications, and may contribute to generalize their application in favor of improved population health. Clinical Trials.gov Identifier: NCT02016014.

Learning in Parallel: Using Parallel Corpora to Enhance Written Language Acquisition at the Beginning Level

ERIC Educational Resources Information Center

Bluemel, Brody

2014-01-01

This article illustrates the pedagogical value of incorporating parallel corpora in foreign language education. It explores the development of a Chinese/English parallel corpus designed specifically for pedagogical application. The corpus tool was created to aid language learners in reading comprehension and writing development by making foreign…

Portable parallel stochastic optimization for the design of aeropropulsion components

NASA Technical Reports Server (NTRS)

Sues, Robert H.; Rhodes, G. S.

1994-01-01

This report presents the results of Phase 1 research to develop a methodology for performing large-scale Multi-disciplinary Stochastic Optimization (MSO) for the design of aerospace systems ranging from aeropropulsion components to complete aircraft configurations. The current research recognizes that such design optimization problems are computationally expensive, and require the use of either massively parallel or multiple-processor computers. The methodology also recognizes that many operational and performance parameters are uncertain, and that uncertainty must be considered explicitly to achieve optimum performance and cost. The objective of this Phase 1 research was to initialize the development of an MSO methodology that is portable to a wide variety of hardware platforms, while achieving efficient, large-scale parallelism when multiple processors are available. The first effort in the project was a literature review of available computer hardware, as well as review of portable, parallel programming environments. The first effort was to implement the MSO methodology for a problem using the portable parallel programming language, Parallel Virtual Machine (PVM). The third and final effort was to demonstrate the example on a variety of computers, including a distributed-memory multiprocessor, a distributed-memory network of workstations, and a single-processor workstation. Results indicate the MSO methodology can be well-applied towards large-scale aerospace design problems. Nearly perfect linear speedup was demonstrated for computation of optimization sensitivity coefficients on both a 128-node distributed-memory multiprocessor (the Intel iPSC/860) and a network of workstations (speedups of almost 19 times achieved for 20 workstations). Very high parallel efficiencies (75 percent for 31 processors and 60 percent for 50 processors) were also achieved for computation of aerodynamic influence coefficients on the Intel. Finally, the multi-level parallelization strategy that will be needed for large-scale MSO problems was demonstrated to be highly efficient. The same parallel code instructions were used on both platforms, demonstrating portability. There are many applications for which MSO can be applied, including NASA's High-Speed-Civil Transport, and advanced propulsion systems. The use of MSO will reduce design and development time and testing costs dramatically.

The effect of earthquake on architecture geometry with non-parallel system irregularity configuration

NASA Astrophysics Data System (ADS)

Teddy, Livian; Hardiman, Gagoek; Nuroji; Tudjono, Sri

2017-12-01

Indonesia is an area prone to earthquake that may cause casualties and damage to buildings. The fatalities or the injured are not largely caused by the earthquake, but by building collapse. The collapse of the building is resulted from the building behaviour against the earthquake, and it depends on many factors, such as architectural design, geometry configuration of structural elements in horizontal and vertical plans, earthquake zone, geographical location (distance to earthquake center), soil type, material quality, and construction quality. One of the geometry configurations that may lead to the collapse of the building is irregular configuration of non-parallel system. In accordance with FEMA-451B, irregular configuration in non-parallel system is defined to have existed if the vertical lateral force-retaining elements are neither parallel nor symmetric with main orthogonal axes of the earthquake-retaining axis system. Such configuration may lead to torque, diagonal translation and local damage to buildings. It does not mean that non-parallel irregular configuration should not be formed on architectural design; however the designer must know the consequence of earthquake behaviour against buildings with irregular configuration of non-parallel system. The present research has the objective to identify earthquake behaviour in architectural geometry with irregular configuration of non-parallel system. The present research was quantitative with simulation experimental method. It consisted of 5 models, where architectural data and model structure data were inputted and analyzed using the software SAP2000 in order to find out its performance, and ETAB2015 to determine the eccentricity occurred. The output of the software analysis was tabulated, graphed, compared and analyzed with relevant theories. For areas of strong earthquake zones, avoid designing buildings which wholly form irregular configuration of non-parallel system. If it is inevitable to design a building with building parts containing irregular configuration of non-parallel system, make it more rigid by forming a triangle module, and use the formula.A good collaboration is needed between architects and structural experts in creating earthquake architecture.

A CS1 pedagogical approach to parallel thinking

NASA Astrophysics Data System (ADS)

Rague, Brian William

Almost all collegiate programs in Computer Science offer an introductory course in programming primarily devoted to communicating the foundational principles of software design and development. The ACM designates this introduction to computer programming course for first-year students as CS1, during which methodologies for solving problems within a discrete computational context are presented. Logical thinking is highlighted, guided primarily by a sequential approach to algorithm development and made manifest by typically using the latest, commercially successful programming language. In response to the most recent developments in accessible multicore computers, instructors of these introductory classes may wish to include training on how to design workable parallel code. Novel issues arise when programming concurrent applications which can make teaching these concepts to beginning programmers a seemingly formidable task. Student comprehension of design strategies related to parallel systems should be monitored to ensure an effective classroom experience. This research investigated the feasibility of integrating parallel computing concepts into the first-year CS classroom. To quantitatively assess student comprehension of parallel computing, an experimental educational study using a two-factor mixed group design was conducted to evaluate two instructional interventions in addition to a control group: (1) topic lecture only, and (2) topic lecture with laboratory work using a software visualization Parallel Analysis Tool (PAT) specifically designed for this project. A new evaluation instrument developed for this study, the Perceptions of Parallelism Survey (PoPS), was used to measure student learning regarding parallel systems. The results from this educational study show a statistically significant main effect among the repeated measures, implying that student comprehension levels of parallel concepts as measured by the PoPS improve immediately after the delivery of any initial three-week CS1 level module when compared with student comprehension levels just prior to starting the course. Survey results measured during the ninth week of the course reveal that performance levels remained high compared to pre-course performance scores. A second result produced by this study reveals no statistically significant interaction effect between the intervention method and student performance as measured by the evaluation instrument over three separate testing periods. However, visual inspection of survey score trends and the low p-value generated by the interaction analysis (0.062) indicate that further studies may verify improved concept retention levels for the lecture w/PAT group.

Parallel computing works

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

An account of the Caltech Concurrent Computation Program (C{sup 3}P), a five year project that focused on answering the question: Can parallel computers be used to do large-scale scientific computations '' As the title indicates, the question is answered in the affirmative, by implementing numerous scientific applications on real parallel computers and doing computations that produced new scientific results. In the process of doing so, C{sup 3}P helped design and build several new computers, designed and implemented basic system software, developed algorithms for frequently used mathematical computations on massively parallel machines, devised performance models and measured the performance of manymore » computers, and created a high performance computing facility based exclusively on parallel computers. While the initial focus of C{sup 3}P was the hypercube architecture developed by C. Seitz, many of the methods developed and lessons learned have been applied successfully on other massively parallel architectures.« less

File concepts for parallel I/O

NASA Technical Reports Server (NTRS)

Crockett, Thomas W.

1989-01-01

The subject of input/output (I/O) was often neglected in the design of parallel computer systems, although for many problems I/O rates will limit the speedup attainable. The I/O problem is addressed by considering the role of files in parallel systems. The notion of parallel files is introduced. Parallel files provide for concurrent access by multiple processes, and utilize parallelism in the I/O system to improve performance. Parallel files can also be used conventionally by sequential programs. A set of standard parallel file organizations is proposed, organizations are suggested, using multiple storage devices. Problem areas are also identified and discussed.

Xyce Parallel Electronic Simulator : users' guide, version 2.0.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoekstra, Robert John; Waters, Lon J.; Rankin, Eric Lamont

2004-06-01

This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been designed as a SPICE-compatible, high-performance analog circuit simulator capable of simulating electrical circuits at a variety of abstraction levels. Primarily, Xyce has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability the current state-of-the-art in the following areas: {sm_bullet} Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). Note that this includes support for most popular parallel and serial computers. {sm_bullet} Improved performance for allmore » numerical kernels (e.g., time integrator, nonlinear and linear solvers) through state-of-the-art algorithms and novel techniques. {sm_bullet} Device models which are specifically tailored to meet Sandia's needs, including many radiation-aware devices. {sm_bullet} A client-server or multi-tiered operating model wherein the numerical kernel can operate independently of the graphical user interface (GUI). {sm_bullet} Object-oriented code design and implementation using modern coding practices that ensure that the Xyce Parallel Electronic Simulator will be maintainable and extensible far into the future. Xyce is a parallel code in the most general sense of the phrase - a message passing of computing platforms. These include serial, shared-memory and distributed-memory parallel implementation - which allows it to run efficiently on the widest possible number parallel as well as heterogeneous platforms. Careful attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved as the number of processors grows. One feature required by designers is the ability to add device models, many specific to the needs of Sandia, to the code. To this end, the device package in the Xyce These input formats include standard analytical models, behavioral models look-up Parallel Electronic Simulator is designed to support a variety of device model inputs. tables, and mesh-level PDE device models. Combined with this flexible interface is an architectural design that greatly simplifies the addition of circuit models. One of the most important feature of Xyce is in providing a platform for computational research and development aimed specifically at the needs of the Laboratory. With Xyce, Sandia now has an 'in-house' capability with which both new electrical (e.g., device model development) and algorithmic (e.g., faster time-integration methods) research and development can be performed. Ultimately, these capabilities are migrated to end users.« less

Optimization under uncertainty of parallel nonlinear energy sinks

NASA Astrophysics Data System (ADS)

Boroson, Ethan; Missoum, Samy; Mattei, Pierre-Olivier; Vergez, Christophe

2017-04-01

Nonlinear Energy Sinks (NESs) are a promising technique for passively reducing the amplitude of vibrations. Through nonlinear stiffness properties, a NES is able to passively and irreversibly absorb energy. Unlike the traditional Tuned Mass Damper (TMD), NESs do not require a specific tuning and absorb energy over a wider range of frequencies. Nevertheless, they are still only efficient over a limited range of excitations. In order to mitigate this limitation and maximize the efficiency range, this work investigates the optimization of multiple NESs configured in parallel. It is well known that the efficiency of a NES is extremely sensitive to small perturbations in loading conditions or design parameters. In fact, the efficiency of a NES has been shown to be nearly discontinuous in the neighborhood of its activation threshold. For this reason, uncertainties must be taken into account in the design optimization of NESs. In addition, the discontinuities require a specific treatment during the optimization process. In this work, the objective of the optimization is to maximize the expected value of the efficiency of NESs in parallel. The optimization algorithm is able to tackle design variables with uncertainty (e.g., nonlinear stiffness coefficients) as well as aleatory variables such as the initial velocity of the main system. The optimal design of several parallel NES configurations for maximum mean efficiency is investigated. Specifically, NES nonlinear stiffness properties, considered random design variables, are optimized for cases with 1, 2, 3, 4, 5, and 10 NESs in parallel. The distributions of efficiency for the optimal parallel configurations are compared to distributions of efficiencies of non-optimized NESs. It is observed that the optimization enables a sharp increase in the mean value of efficiency while reducing the corresponding variance, thus leading to more robust NES designs.

Differential Draining of Parallel-Fed Propellant Tanks in Morpheus and Apollo Flight

NASA Technical Reports Server (NTRS)

Hurlbert, Eric; Guardado, Hector; Hernandez, Humberto; Desai, Pooja

2015-01-01

Parallel-fed propellant tanks are an advantageous configuration for many spacecraft. Parallel-fed tanks allow the center of gravity (cg) to be maintained over the engine(s), as opposed to serial-fed propellant tanks which result in a cg shift as propellants are drained from tank one tank first opposite another. Parallel-fed tanks also allow for tank isolation if that is needed. Parallel tanks and feed systems have been used in several past vehicles including the Apollo Lunar Module. The design of the feedsystem connecting the parallel tank is critical to maintain balance in the propellant tanks. The design must account for and minimize the effect of manufacturing variations that could cause delta-p or mass flowrate differences, which would lead to propellant imbalance. Other sources of differential draining will be discussed. Fortunately, physics provides some self-correcting behaviors that tend to equalize any initial imbalance. The question concerning whether or not active control of propellant in each tank is required or can be avoided or not is also important to answer. In order to provide data on parallel-fed tanks and differential draining in flight for cryogenic propellants (as well as any other fluid), a vertical test bed (flying lander) for terrestrial use was employed. The Morpheus vertical test bed is a parallel-fed propellant tank system that uses passive design to keep the propellant tanks balanced. The system is operated in blow down. The Morpheus vehicle was instrumented with a capacitance level sensor in each propellant tank in order to measure the draining of propellants in over 34 tethered and 12 free flights. Morpheus did experience an approximately 20 lb/m imbalance in one pair of tanks. The cause of this imbalance will be discussed. This paper discusses the analysis, design, flight simulation vehicle dynamic modeling, and flight test of the Morpheus parallel-fed propellant. The Apollo LEM data is also examined in this summary report of the flight data.

National Combustion Code: Parallel Performance

NASA Technical Reports Server (NTRS)

Babrauckas, Theresa

2001-01-01

This report discusses the National Combustion Code (NCC). The NCC is an integrated system of codes for the design and analysis of combustion systems. The advanced features of the NCC meet designers' requirements for model accuracy and turn-around time. The fundamental features at the inception of the NCC were parallel processing and unstructured mesh. The design and performance of the NCC are discussed.

The Effect of the Infant Behavioral Assessment and Intervention Program on Mother-Infant Interaction after Very Preterm Birth

ERIC Educational Resources Information Center

Meijssen, Dominique; Wolf, Marie-Jeanne; Koldewijn, Karen; Houtzager, Bregje A.; Van Wassenaer, Aleid; Tronick, Ed; Kok, Joke; Van Baar, Anneloes

2010-01-01

Background: Prematurity and perinatal insults lead to increased developmental vulnerability. The home-based Infant Behavioral Assessment and Intervention Program (IBAIP) was designed to improve development of preterm infants. In a multicenter randomized controlled trial the effect of IBAIP on mother-infant interaction was studied as a secondary…

Ropes: Support for collective opertions among distributed threads

NASA Technical Reports Server (NTRS)

Haines, Matthew; Mehrotra, Piyush; Cronk, David

1995-01-01

Lightweight threads are becoming increasingly useful in supporting parallelism and asynchronous control structures in applications and language implementations. Recently, systems have been designed and implemented to support interprocessor communication between lightweight threads so that threads can be exploited in a distributed memory system. Their use, in this setting, has been largely restricted to supporting latency hiding techniques and functional parallelism within a single application. However, to execute data parallel codes independent of other threads in the system, collective operations and relative indexing among threads are required. This paper describes the design of ropes: a scoping mechanism for collective operations and relative indexing among threads. We present the design of ropes in the context of the Chant system, and provide performance results evaluating our initial design decisions.

Xyce™ Parallel Electronic Simulator Users' Guide, Version 6.5.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keiter, Eric R.; Aadithya, Karthik V.; Mei, Ting

This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been designed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). This includes support for most popular parallel and serial computers. A differential-algebraic-equation (DAE) formulation, which better isolates the device model package from solver algorithms. This allows one to developmore » new types of analysis without requiring the implementation of analysis-specific device models. Device models that are specifically tailored to meet Sandia's needs, including some radiation- aware devices (for Sandia users only). Object-oriented code design and implementation using modern coding practices. Xyce is a parallel code in the most general sense of the phrase -- a message passing parallel implementation -- which allows it to run efficiently a wide range of computing platforms. These include serial, shared-memory and distributed-memory parallel platforms. Attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved as the number of processors grows. The information herein is subject to change without notice. Copyright © 2002-2016 Sandia Corporation. All rights reserved.« less

Multicenter Clinical Trial of the Nucleus® Hybrid™ S8 Cochlear Implant: Final Outcomes

PubMed Central

Gantz, Bruce J; Dunn, Camille; Oleson, Jacob; Hansen, Marlan; Parkinson, Aaron; Turner, Christopher

2015-01-01

Objective The concept expanding electrical speech processing to those with more residual acoustic hearing with a less invasive shorter cochlear implant has been ongoing since 1999. A multi-center study of the Nucleus Hybrid S8 CI took place between 2002–11. This report describes the final outcomes of this clinical trial. Study Design Multi-Center longitudinal single subject design Methods Eighty-seven subjects received a Nucleus® Hybrid™ S8 implant in their poorer ear. Speech perception in quiet (CNC words) and in noise (BKB-SIN) was collected pre- and post-operatively at 3, 6, and 12 months. Subjective questionnaire data using the APHAB was also collected. Results Some level of hearing preservation was accomplished in 98% subjects with 90% maintaining a functional low-frequency pure-tone average (LFPTA) at initial activation. By 12 months, 5 subjects had total hearing loss and 80% of subjects maintained functional hearing. CNC words demonstrated that 82.5% and 87.5% of subjects had significant improvements in the Hybrid and Combined conditions. The majority of had improvements with BKB-SIN. Results also indicated that as long as subjects maintained at least a severe LFPTA, there was significant improvement in speech understanding. Furthermore, all subjects reported positive improvements in hearing in three of the 4 subscales of the APHAB. Conclusion The concept of hybrid speech processing has significant advantages for subjects with residual low-frequency hearing. In this study, the Nucleus® Hybrid™ S8 provided improved word understanding in quiet and noise. Additionally, there appears to be stability of the residual hearing after initial activation of the device. Level of evidence 2c PMID:26756395

Multicenter Evaluation of the Cepheid Xpert Methicillin-Resistant Staphylococcus aureus (MRSA) Test as a Rapid Screening Method for Detection of MRSA in Nares▿

PubMed Central

Wolk, D. M.; Picton, E.; Johnson, D.; Davis, T.; Pancholi, P.; Ginocchio, C. C.; Finegold, S.; Welch, D. F.; de Boer, M.; Fuller, D.; Solomon, M. C.; Rogers, B.; Mehta, M. S.; Peterson, L. R.

2009-01-01

The first U.S. multicenter clinical trial to assess the performance of the Cepheid Xpert MRSA assay (Xpert MRSA) was conducted. The assay is a qualitative test designed for the rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) directly from nares swabs. This novel test combines integrated nucleic acid extraction and automated real-time PCR for the detection of a MRSA-specific signature sequence. A total of 1,077 nares specimens were collected from seven geographically distinct health care sites across the United States with prevalence rates ranging from 5.2% to 44%. Nares specimens were tested by (i) the Xpert MRSA assay, (ii) direct culture on CHROMagar MRSA medium (direct CM culture), and (iii) broth-enriched culture (Trypticase soy broth with 6.5% sodium chloride) followed by plating onto CHROMagar MRSA medium (broth-enriched CM culture). When direct CM culture was designated the reference method, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the Xpert MRSA assay were 94.3%, 93.2%, 73.0%, and 98.8%, respectively. When broth-enriched CM culture was used as the reference method, the clinical sensitivity, specificity, PPV, and NPV of the Xpert MRSA assay were 86.3%, 94.9%, 80.5%, and 96.6%, respectively. The BD GeneOhm MRSA (BDGO) assay was performed as a comparative molecular method. No statistical performance differences were observed between the Xpert MRSA and BDGO assays when they were compared to culture methods. From this large-scale, multicenter clinical comparison, we conclude that the Xpert MRSA assay is a simple, rapid, and accurate method for performing active surveillance for MRSA in a variety of health care populations. PMID:19129414

Effectiveness of a smartphone application for improving healthy lifestyles, a randomized clinical trial (EVIDENT II): study protocol

PubMed Central

2014-01-01

Background New technologies could facilitate changes in lifestyle and improve public health. However, no large randomized, controlled studies providing scientific evidence of the benefits of their use have been made. The aims of this study are to develop and validate a smartphone application, and to evaluate the effect of adding this tool to a standardized intervention designed to improve adherence to the Mediterranean diet and to physical activity. An evaluation is also made of the effect of modifying habits upon vascular structure and function, and therefore on arterial aging. Methods/Design A randomized, double-blind, multicenter, parallel group clinical trial will be carried out. A total of 1215 subjects under 70 years of age from the EVIDENT trial will be included. Counseling common to both groups (control and intervention) will be provided on adaptation to the Mediterranean diet and on physical activity. The intervention group moreover will receive training on the use of a smartphone application designed to promote a healthy diet and increased physical activity, and will use the application for three months. The main study endpoints will be the changes in physical activity, assessed by accelerometer and the 7-day Physical Activity Recall (PAR) interview, and adaptation to the Mediterranean diet, as evaluated by an adherence questionnaire and a food frequency questionnaire (FFQ). Evaluation also will be made of vascular structure and function based on central arterial pressure, the radial augmentation index, pulse velocity, the cardio-ankle vascular index, and carotid intima-media thickness. Discussion Confirmation that the new technologies are useful for promoting healthier lifestyles and that their effects are beneficial in terms of arterial aging will have important clinical implications, and may contribute to generalize their application in favor of improved population health. Trial registration Clinical Trials.gov Identifier: NCT02016014 PMID:24628961

Electroacupuncture for chemotherapy-induced peripheral neuropathy: study protocol for a pilot multicentre randomized, patient-assessor-blinded, controlled trial

PubMed Central

2013-01-01

Background Chemotherapy-induced peripheral neuropathy (CIPN) is the main dose-limiting side effect of neurotoxic chemotherapeutic agents. CIPN can lead not only to loss of physical function, difficulties in activities of daily living (ADLs), and decreased quality of life, but also to dose reduction, delay or even cessation of treatment. Currently, there are few proven effective treatments for CIPN. This randomized controlled clinical trial is designed to evaluate the effects and safety of electroacupuncture (EA) for patients with CIPN. Methods/design This is a multicenter, two-armed, parallel-design, patient-assessor-blinded, randomized, sham-controlled clinical trial. Forty eligible patients with CIPN will be randomized in a ratio of 1:1 to the EA or sham EA arms. During the treatment phase, patients will undergo eight sessions of verum EA or sham EA twice weekly for four weeks, and then will be followed-up for eight weeks. Electrical stimulation in the EA group will consist of a mixed frequency of 2/120 Hz and 80% of bearable intensity. Sham EA will be applied to non-acupoints, with shallow needle insertion and no current. All outcomes and analyses of results will be assessed by researchers blinded to treatment allocation. The effects of EA on CIPN will be evaluated according to both subjective and objective outcome measures. The primary outcome measure will be the European Organization for Research and Treatment of Cancer (EORTC) quality of life questionnaire to assess CIPN (QLQ-CIPN20). The secondary outcome measures will be the results on the numerical rating scale, the Semmes-Weinstein monofilament test, the nerve conduction study, and the EORTC QLQ-C30, as well as the patient’s global impression of change and adverse events. Safety will be assessed at each visit. Discussion The results of this on-going study will provide clinical evidence for the effects and safety of EA for CIPN compared with sham EA. Trial registration Clinical Research Information Service: KCT0000506 PMID:23945074

Demonstration of Nonlinearity Bias in the Measurement of the Apparent Diffusion Coefficient in Multicenter Trials

PubMed Central

Malyarenko, Dariya; Newitt, David; Wilmes, Lisa; Tudorica, Alina; Helmer, Karl G.; Arlinghaus, Lori R.; Jacobs, Michael A.; Jajamovich, Guido; Taouli, Bachir; Yankeelov, Thomas E.; Huang, Wei; Chenevert, Thomas L.

2015-01-01

Purpose Characterize system-specific bias across common magnetic resonance imaging (MRI) platforms for quantitative diffusion measurements in multicenter trials. Methods Diffusion weighted imaging (DWI) was performed on an ice-water phantom along the superior-inferior (SI) and right-left (RL) orientations spanning ±150 mm. The same scanning protocol was implemented on 14 MRI systems at seven imaging centers. The bias was estimated as a deviation of measured from known apparent diffusion coefficient (ADC) along individual DWI directions. The relative contributions of gradient nonlinearity, shim errors, imaging gradients and eddy currents were assessed independently. The observed bias errors were compared to numerical models. Results The measured systematic ADC errors scaled quadratically with offset from isocenter, and ranged between −55% (SI) and 25% (RL). Nonlinearity bias was dependent on system design and diffusion gradient direction. Consistent with numerical models, minor ADC errors (±5%) due to shim, imaging and eddy currents were mitigated by double echo DWI and image co-registration of individual gradient directions. Conclusion The analysis confirms gradient nonlinearity as a major source of spatial DW bias and variability in off-center ADC measurements across MRI platforms, with minor contributions from shim, imaging gradients and eddy currents. The developed protocol enables empiric description of systematic bias in multicenter quantitative DWI studies. PMID:25940607

Demonstration of nonlinearity bias in the measurement of the apparent diffusion coefficient in multicenter trials.

PubMed

Malyarenko, Dariya I; Newitt, David; J Wilmes, Lisa; Tudorica, Alina; Helmer, Karl G; Arlinghaus, Lori R; Jacobs, Michael A; Jajamovich, Guido; Taouli, Bachir; Yankeelov, Thomas E; Huang, Wei; Chenevert, Thomas L

2016-03-01

Characterize system-specific bias across common magnetic resonance imaging (MRI) platforms for quantitative diffusion measurements in multicenter trials. Diffusion weighted imaging (DWI) was performed on an ice-water phantom along the superior-inferior (SI) and right-left (RL) orientations spanning ± 150 mm. The same scanning protocol was implemented on 14 MRI systems at seven imaging centers. The bias was estimated as a deviation of measured from known apparent diffusion coefficient (ADC) along individual DWI directions. The relative contributions of gradient nonlinearity, shim errors, imaging gradients, and eddy currents were assessed independently. The observed bias errors were compared with numerical models. The measured systematic ADC errors scaled quadratically with offset from isocenter, and ranged between -55% (SI) and 25% (RL). Nonlinearity bias was dependent on system design and diffusion gradient direction. Consistent with numerical models, minor ADC errors (± 5%) due to shim, imaging and eddy currents were mitigated by double echo DWI and image coregistration of individual gradient directions. The analysis confirms gradient nonlinearity as a major source of spatial DW bias and variability in off-center ADC measurements across MRI platforms, with minor contributions from shim, imaging gradients and eddy currents. The developed protocol enables empiric description of systematic bias in multicenter quantitative DWI studies. © 2015 Wiley Periodicals, Inc.

Applications of Parallel Process HiMAP for Large Scale Multidisciplinary Problems

NASA Technical Reports Server (NTRS)

Guruswamy, Guru P.; Potsdam, Mark; Rodriguez, David; Kwak, Dochay (Technical Monitor)

2000-01-01

HiMAP is a three level parallel middleware that can be interfaced to a large scale global design environment for code independent, multidisciplinary analysis using high fidelity equations. Aerospace technology needs are rapidly changing. Computational tools compatible with the requirements of national programs such as space transportation are needed. Conventional computation tools are inadequate for modern aerospace design needs. Advanced, modular computational tools are needed, such as those that incorporate the technology of massively parallel processors (MPP).

Parallelization of Program to Optimize Simulated Trajectories (POST3D)

NASA Technical Reports Server (NTRS)

Hammond, Dana P.; Korte, John J. (Technical Monitor)

2001-01-01

This paper describes the parallelization of the Program to Optimize Simulated Trajectories (POST3D). POST3D uses a gradient-based optimization algorithm that reaches an optimum design point by moving from one design point to the next. The gradient calculations required to complete the optimization process, dominate the computational time and have been parallelized using a Single Program Multiple Data (SPMD) on a distributed memory NUMA (non-uniform memory access) architecture. The Origin2000 was used for the tests presented.

Options for Parallelizing a Planning and Scheduling Algorithm

NASA Technical Reports Server (NTRS)

Clement, Bradley J.; Estlin, Tara A.; Bornstein, Benjamin D.

2011-01-01

Space missions have a growing interest in putting multi-core processors onboard spacecraft. For many missions processing power significantly slows operations. We investigate how continual planning and scheduling algorithms can exploit multi-core processing and outline different potential design decisions for a parallelized planning architecture. This organization of choices and challenges helps us with an initial design for parallelizing the CASPER planning system for a mesh multi-core processor. This work extends that presented at another workshop with some preliminary results.

Scalable Unix commands for parallel processors : a high-performance implementation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ong, E.; Lusk, E.; Gropp, W.

2001-06-22

We describe a family of MPI applications we call the Parallel Unix Commands. These commands are natural parallel versions of common Unix user commands such as ls, ps, and find, together with a few similar commands particular to the parallel environment. We describe the design and implementation of these programs and present some performance results on a 256-node Linux cluster. The Parallel Unix Commands are open source and freely available.

Parallel language constructs for tensor product computations on loosely coupled architectures

NASA Technical Reports Server (NTRS)

Mehrotra, Piyush; Van Rosendale, John

1989-01-01

A set of language primitives designed to allow the specification of parallel numerical algorithms at a higher level is described. The authors focus on tensor product array computations, a simple but important class of numerical algorithms. They consider first the problem of programming one-dimensional kernel routines, such as parallel tridiagonal solvers, and then look at how such parallel kernels can be combined to form parallel tensor product algorithms.

The pediatric heart network: meeting the challenges to multicenter studies in pediatric heart disease

PubMed Central

Burns, Kristin M.; Pemberton, Victoria L.; Pearson, Gail D.

2017-01-01

Purpose of review Because of the relatively small numbers of pediatric patients with congenital heart disease cared for in any individual center, there is a significant need for multicenter clinical studies to validate new medical or surgical therapies. The Pediatric Heart Network (PHN), with 15 years of experience in multicenter clinical research, has tackled numerous challenges when conducting multicenter studies. Recent findings This review describes the challenges encountered and the strategies employed to conduct high-quality, collaborative research in pediatric cardiovascular disease. Summary Sharing lessons learned from the PHN can provide guidance to investigators interested in conducting pediatric multicenter studies. PMID:26196261

Critical appraisal of arguments for the delayed-start design proposed as alternative to the parallel-group randomized clinical trial design in the field of rare disease.

PubMed

Spineli, Loukia M; Jenz, Eva; Großhennig, Anika; Koch, Armin

2017-08-17

A number of papers have proposed or evaluated the delayed-start design as an alternative to the standard two-arm parallel group randomized clinical trial (RCT) design in the field of rare disease. However the discussion is felt to lack a sufficient degree of consideration devoted to the true virtues of the delayed start design and the implications either in terms of required sample-size, overall information, or interpretation of the estimate in the context of small populations. To evaluate whether there are real advantages of the delayed-start design particularly in terms of overall efficacy and sample size requirements as a proposed alternative to the standard parallel group RCT in the field of rare disease. We used a real-life example to compare the delayed-start design with the standard RCT in terms of sample size requirements. Then, based on three scenarios regarding the development of the treatment effect over time, the advantages, limitations and potential costs of the delayed-start design are discussed. We clarify that delayed-start design is not suitable for drugs that establish an immediate treatment effect, but for drugs with effects developing over time, instead. In addition, the sample size will always increase as an implication for a reduced time on placebo resulting in a decreased treatment effect. A number of papers have repeated well-known arguments to justify the delayed-start design as appropriate alternative to the standard parallel group RCT in the field of rare disease and do not discuss the specific needs of research methodology in this field. The main point is that a limited time on placebo will result in an underestimated treatment effect and, in consequence, in larger sample size requirements compared to those expected under a standard parallel-group design. This also impacts on benefit-risk assessment.

Effect of Armodafinil on Cortical Activity and Working Memory in Patients with Residual Excessive Sleepiness Associated with CPAP-Treated OSA: A Multicenter fMRI Study

PubMed Central

Greve, Douglas N.; Duntley, Stephen P.; Larson-Prior, Linda; Krystal, Andrew D.; Diaz, Michele T.; Drummond, Sean P. A.; Thein, Stephen G.; Kushida, Clete A.; Yang, Ronghua; Thomas, Robert J.

2014-01-01

Study Objective: To assess the effect of armodafinil on task-related prefrontal cortex activation using functional magnetic resonance imaging (fMRI) in patients with obstructive sleep apnea (OSA) and excessive sleepiness despite continuous positive airway pressure (CPAP) therapy. Methods: This 2-week, multicenter, prospective, randomized, double-blind, placebo-controlled, parallel-group study was conducted at five neuroimaging sites and four collaborating clinical study centers in the United States. Patients were 40 right-handed or ambidextrous men and women aged between 18 and 60 years, with OSA and persistent sleepiness, as determined by multiple sleep latency and Epworth Sleepiness Scale scores, despite effective, stable use of CPAP. Treatment was randomized (1:1) to once-daily armodafinil 200 mg or placebo. The primary efficacy outcome was a change from baseline at week 2 in the volume of activation meeting the predefined threshold in the dorsolateral prefrontal cortex during a 2-back working memory task. The key secondary measure was the change in task response latency. Results: No significant differences were observed between treatment groups in the primary or key secondary outcomes. Armodafinil was generally well tolerated. The most common adverse events (occurring in more than one patient [5%]) were headache (19%), nasopharyngitis (14%), and diarrhea (10%). Conclusions: Armodafinil did not improve fMRI-measured functional brain activation in CPAP-treated patients with OSA and excessive sleepiness. Study Registration: Double-Blind, Placebo-Controlled, Functional Neuroimaging Study of Armodafinil (200 mg/Day) on Prefrontal Cortical Activation in Patients With Residual Excessive Sleepiness Associated With Obstructive Sleep Apnea/Hypopnea. ClinicalTrials.gov Identifier: NCT00711516. http://www.clinicaltrials.gov/ct2/show/study/NCT00711516 Citation: Greve DN; Duntley SP; Larson-Prior L; Krystal AD; Diaz MT; Drummond SP; Thein SG; Kushida CA; Yang R; Thomas RJ. Effect of armodafinil on cortical activity and working memory in patients with residual excessive sleepiness associated with CPAP-treated OSA: a multicenter fMRI study. J Clin Sleep Med 2014;10(2):143-153. PMID:24532997

Design Method of Digital Optimal Control Scheme and Multiple Paralleled Bridge Type Current Amplifier for Generating Gradient Magnetic Fields in MRI Systems

NASA Astrophysics Data System (ADS)

Watanabe, Shuji; Takano, Hiroshi; Fukuda, Hiroya; Hiraki, Eiji; Nakaoka, Mutsuo

This paper deals with a digital control scheme of multiple paralleled high frequency switching current amplifier with four-quadrant chopper for generating gradient magnetic fields in MRI (Magnetic Resonance Imaging) systems. In order to track high precise current pattern in Gradient Coils (GC), the proposal current amplifier cancels the switching current ripples in GC with each other and designed optimum switching gate pulse patterns without influences of the large filter current ripple amplitude. The optimal control implementation and the linear control theory in GC current amplifiers have affinity to each other with excellent characteristics. The digital control system can be realized easily through the digital control implementation, DSPs or microprocessors. Multiple-parallel operational microprocessors realize two or higher paralleled GC current pattern tracking amplifier with optimal control design and excellent results are given for improving the image quality of MRI systems.

Symplectic molecular dynamics simulations on specially designed parallel computers.

PubMed

Borstnik, Urban; Janezic, Dusanka

2005-01-01

We have developed a computer program for molecular dynamics (MD) simulation that implements the Split Integration Symplectic Method (SISM) and is designed to run on specialized parallel computers. The MD integration is performed by the SISM, which analytically treats high-frequency vibrational motion and thus enables the use of longer simulation time steps. The low-frequency motion is treated numerically on specially designed parallel computers, which decreases the computational time of each simulation time step. The combination of these approaches means that less time is required and fewer steps are needed and so enables fast MD simulations. We study the computational performance of MD simulation of molecular systems on specialized computers and provide a comparison to standard personal computers. The combination of the SISM with two specialized parallel computers is an effective way to increase the speed of MD simulations up to 16-fold over a single PC processor.

Skewed steel bridges, part ii : cross-frame and connection design to ensure brace effectiveness : technical summary.

DOT National Transportation Integrated Search

2017-08-01

Skewed bridges in Kansas are often designed such that the cross-frames are carried parallel to the skew angle up to 40, while many other states place cross-frames perpendicular to the girder for skew angles greater than 20. Skewed-parallel cross-...

Skewed steel bridges, part ii : cross-frame and connection design to ensure brace effectiveness : final report.

DOT National Transportation Integrated Search

2017-08-01

Skewed bridges in Kansas are often designed such that the cross-frames are carried parallel to the skew angle up to 40, while many other states place cross-frames perpendicular to the girder for skew angles greater than 20. Skewed-parallel cross-...

Design of a switch matrix gate/bulk driver controller for thin film lithium microbatteries using microwave SOI technology

NASA Technical Reports Server (NTRS)

Whitacre, J.; West, W. C.; Mojarradi, M.; Sukumar, V.; Hess, H.; Li, H.; Buck, K.; Cox, D.; Alahmad, M.; Zghoul, F. N.;

Fast I/O for Massively Parallel Applications

NASA Technical Reports Server (NTRS)

OKeefe, Matthew T.

1996-01-01

The two primary goals for this report were the design, contruction and modeling of parallel disk arrays for scientific visualization and animation, and a study of the IO requirements of highly parallel applications. In addition, further work in parallel display systems required to project and animate the very high-resolution frames resulting from our supercomputing simulations in ocean circulation and compressible gas dynamics.

Simplified Parallel Domain Traversal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erickson III, David J

2011-01-01

Many data-intensive scientific analysis techniques require global domain traversal, which over the years has been a bottleneck for efficient parallelization across distributed-memory architectures. Inspired by MapReduce and other simplified parallel programming approaches, we have designed DStep, a flexible system that greatly simplifies efficient parallelization of domain traversal techniques at scale. In order to deliver both simplicity to users as well as scalability on HPC platforms, we introduce a novel two-tiered communication architecture for managing and exploiting asynchronous communication loads. We also integrate our design with advanced parallel I/O techniques that operate directly on native simulation output. We demonstrate DStep bymore » performing teleconnection analysis across ensemble runs of terascale atmospheric CO{sub 2} and climate data, and we show scalability results on up to 65,536 IBM BlueGene/P cores.« less

PARAMESH: A Parallel Adaptive Mesh Refinement Community Toolkit

NASA Technical Reports Server (NTRS)

MacNeice, Peter; Olson, Kevin M.; Mobarry, Clark; deFainchtein, Rosalinda; Packer, Charles

1999-01-01

In this paper, we describe a community toolkit which is designed to provide parallel support with adaptive mesh capability for a large and important class of computational models, those using structured, logically cartesian meshes. The package of Fortran 90 subroutines, called PARAMESH, is designed to provide an application developer with an easy route to extend an existing serial code which uses a logically cartesian structured mesh into a parallel code with adaptive mesh refinement. Alternatively, in its simplest use, and with minimal effort, it can operate as a domain decomposition tool for users who want to parallelize their serial codes, but who do not wish to use adaptivity. The package can provide them with an incremental evolutionary path for their code, converting it first to uniformly refined parallel code, and then later if they so desire, adding adaptivity.

Optimal Design of Passive Power Filters Based on Pseudo-parallel Genetic Algorithm

NASA Astrophysics Data System (ADS)

Li, Pei; Li, Hongbo; Gao, Nannan; Niu, Lin; Guo, Liangfeng; Pei, Ying; Zhang, Yanyan; Xu, Minmin; Chen, Kerui

2017-05-01

The economic costs together with filter efficiency are taken as targets to optimize the parameter of passive filter. Furthermore, the method of combining pseudo-parallel genetic algorithm with adaptive genetic algorithm is adopted in this paper. In the early stages pseudo-parallel genetic algorithm is introduced to increase the population diversity, and adaptive genetic algorithm is used in the late stages to reduce the workload. At the same time, the migration rate of pseudo-parallel genetic algorithm is improved to change with population diversity adaptively. Simulation results show that the filter designed by the proposed method has better filtering effect with lower economic cost, and can be used in engineering.

Language Classification using N-grams Accelerated by FPGA-based Bloom Filters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacob, A; Gokhale, M

N-Gram (n-character sequences in text documents) counting is a well-established technique used in classifying the language of text in a document. In this paper, n-gram processing is accelerated through the use of reconfigurable hardware on the XtremeData XD1000 system. Our design employs parallelism at multiple levels, with parallel Bloom Filters accessing on-chip RAM, parallel language classifiers, and parallel document processing. In contrast to another hardware implementation (HAIL algorithm) that uses off-chip SRAM for lookup, our highly scalable implementation uses only on-chip memory blocks. Our implementation of end-to-end language classification runs at 85x comparable software and 1.45x the competing hardware design.

INVITED TOPICAL REVIEW: Parallel magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Larkman, David J.; Nunes, Rita G.

2007-04-01

Parallel imaging has been the single biggest innovation in magnetic resonance imaging in the last decade. The use of multiple receiver coils to augment the time consuming Fourier encoding has reduced acquisition times significantly. This increase in speed comes at a time when other approaches to acquisition time reduction were reaching engineering and human limits. A brief summary of spatial encoding in MRI is followed by an introduction to the problem parallel imaging is designed to solve. There are a large number of parallel reconstruction algorithms; this article reviews a cross-section, SENSE, SMASH, g-SMASH and GRAPPA, selected to demonstrate the different approaches. Theoretical (the g-factor) and practical (coil design) limits to acquisition speed are reviewed. The practical implementation of parallel imaging is also discussed, in particular coil calibration. How to recognize potential failure modes and their associated artefacts are shown. Well-established applications including angiography, cardiac imaging and applications using echo planar imaging are reviewed and we discuss what makes a good application for parallel imaging. Finally, active research areas where parallel imaging is being used to improve data quality by repairing artefacted images are also reviewed.

Multirate-based fast parallel algorithms for 2-D DHT-based real-valued discrete Gabor transform.

PubMed

Tao, Liang; Kwan, Hon Keung

2012-07-01

Novel algorithms for the multirate and fast parallel implementation of the 2-D discrete Hartley transform (DHT)-based real-valued discrete Gabor transform (RDGT) and its inverse transform are presented in this paper. A 2-D multirate-based analysis convolver bank is designed for the 2-D RDGT, and a 2-D multirate-based synthesis convolver bank is designed for the 2-D inverse RDGT. The parallel channels in each of the two convolver banks have a unified structure and can apply the 2-D fast DHT algorithm to speed up their computations. The computational complexity of each parallel channel is low and is independent of the Gabor oversampling rate. All the 2-D RDGT coefficients of an image are computed in parallel during the analysis process and can be reconstructed in parallel during the synthesis process. The computational complexity and time of the proposed parallel algorithms are analyzed and compared with those of the existing fastest algorithms for 2-D discrete Gabor transforms. The results indicate that the proposed algorithms are the fastest, which make them attractive for real-time image processing.

Centrifugal multiplexing fixed-volume dispenser on a plastic lab-on-a-disk for parallel biochemical single-end-point assays

PubMed Central

La, Moonwoo; Park, Sang Min; Kim, Dong Sung

2015-01-01

In this study, a multiple sample dispenser for precisely metered fixed volumes was successfully designed, fabricated, and fully characterized on a plastic centrifugal lab-on-a-disk (LOD) for parallel biochemical single-end-point assays. The dispenser, namely, a centrifugal multiplexing fixed-volume dispenser (C-MUFID) was designed with microfluidic structures based on the theoretical modeling about a centrifugal circumferential filling flow. The designed LODs were fabricated with a polystyrene substrate through micromachining and they were thermally bonded with a flat substrate. Furthermore, six parallel metering and dispensing assays were conducted at the same fixed-volume (1.27 μl) with a relative variation of ±0.02 μl. Moreover, the samples were metered and dispensed at different sub-volumes. To visualize the metering and dispensing performances, the C-MUFID was integrated with a serpentine micromixer during parallel centrifugal mixing tests. Parallel biochemical single-end-point assays were successfully conducted on the developed LOD using a standard serum with albumin, glucose, and total protein reagents. The developed LOD could be widely applied to various biochemical single-end-point assays which require different volume ratios of the sample and reagent by controlling the design of the C-MUFID. The proposed LOD is feasible for point-of-care diagnostics because of its mass-producible structures, reliable metering/dispensing performance, and parallel biochemical single-end-point assays, which can identify numerous biochemical. PMID:25610516

PISCES: An environment for parallel scientific computation

NASA Technical Reports Server (NTRS)

Pratt, T. W.

1985-01-01

The parallel implementation of scientific computing environment (PISCES) is a project to provide high-level programming environments for parallel MIMD computers. Pisces 1, the first of these environments, is a FORTRAN 77 based environment which runs under the UNIX operating system. The Pisces 1 user programs in Pisces FORTRAN, an extension of FORTRAN 77 for parallel processing. The major emphasis in the Pisces 1 design is in providing a carefully specified virtual machine that defines the run-time environment within which Pisces FORTRAN programs are executed. Each implementation then provides the same virtual machine, regardless of differences in the underlying architecture. The design is intended to be portable to a variety of architectures. Currently Pisces 1 is implemented on a network of Apollo workstations and on a DEC VAX uniprocessor via simulation of the task level parallelism. An implementation for the Flexible Computing Corp. FLEX/32 is under construction. An introduction to the Pisces 1 virtual computer and the FORTRAN 77 extensions is presented. An example of an algorithm for the iterative solution of a system of equations is given. The most notable features of the design are the provision for several granularities of parallelism in programs and the provision of a window mechanism for distributed access to large arrays of data.

Increasing complexity of clinical research in gastroenterology: implications for the training of clinician-scientists.

PubMed

Scott, Frank I; McConnell, Ryan A; Lewis, Matthew E; Lewis, James D

2012-04-01

Significant advances have been made in clinical and epidemiologic research methods over the past 30 years. We sought to demonstrate the impact of these advances on published gastroenterology research from 1980 to 2010. Twenty original clinical articles were randomly selected from each of three journals from 1980, 1990, 2000, and 2010. Each article was assessed for topic, whether the outcome was clinical or physiologic, study design, sample size, number of authors and centers collaborating, reporting of various statistical methods, and external funding. From 1980 to 2010, there was a significant increase in analytic studies, clinical outcomes, number of authors per article, multicenter collaboration, sample size, and external funding. There was increased reporting of P values, confidence intervals, and power calculations, and increased use of large multicenter databases, multivariate analyses, and bioinformatics. The complexity of clinical gastroenterology and hepatology research has increased dramatically, highlighting the need for advanced training of clinical investigators.

[Attaching importance to study on acute health risk assessment and adaptation of air pollution and climate change].

PubMed

Shi, X M

2017-03-10

Air pollution and climate change have become key environmental and public health problems around the world, which poses serious threat to human health. How to assess and mitigate the health risks and increase the adaptation of the public have become an urgent topic of research in this area. The six papers in this issue will provide important and rich information on design, analysis method, indicator selection and setting about acute health risk assessment and adaptation study of air pollution and climate change in China, reflecting the advanced conceptions of multi-center and area-specific study and multi-pollutant causing acute effect study. However, the number and type of the cities included in these studies were still limited. In future, researchers should further expand detailed multi-center and multi-area study coverage, conduct area specific predicting and early warning study and strengthen adaptation study.

Effects of a Psychological Intervention in a Primary Health Care Center for Caregivers of Dependent Relatives: A Randomized Trial

ERIC Educational Resources Information Center

Rodriguez-Sanchez, Emiliano; Patino-Alonso, Maria C.; Mora-Simon, Sara; Gomez-Marcos, Manuel A.; Perez-Penaranda, Anibal; Losada-Baltar, Andres; Garcia-Ortiz, Luis

2013-01-01

Purpose: To assess, in the context of Primary Health Care (PHC), the effect of a psychological intervention in mental health among caregivers (CGs) of dependent relatives. Design and Methods: Randomized multicenter, controlled clinical trial. The 125 CGs included in the trial were receiving health care in PHC. Inclusion criteria: Identifying…

NASA Ares I Crew Launch Vehicle Upper Stage Overview

NASA Technical Reports Server (NTRS)

Davusm Daniel J.; McArthur, J. Craig

2008-01-01

By incorporating rigorous engineering practices, innovative manufacturing processes and test techniques, a unique multi-center government/contractor partnership, and a clean-sheet design developed around the primary requirements for the International Space Station (ISS) and Lunar missions, the Upper Stage Element of NASA's Crew Launch Vehicle (CLV), the "Ares I," is a vital part of the Constellation Program's transportation system.

NASA Ares I Crew Launch Vehicle Upper State Overview

NASA Technical Reports Server (NTRS)

Davis, Daniel J.

2008-01-01

By incorporating rigorous engineering practices, innovative manufacturing processes and test techniques, a unique multi-center government/contractor partnership, and a clean-sheet design developed around the primary requirements for the International Space Station (ISS) and Lunar missions, the Upper Stage Element of NASA s Crew Launch Vehicle (CLV), the "Ares I," is a vital part of the Constellation Program s transportation system.

Plasma 25-hydroxyvitamin D and progression to diabetes in patients at risk for diabetes: an ancillary analysis in the diabetes prevention program

USDA-ARS?s Scientific Manuscript database

We investigated the association between vitamin D status, assessed by plasma 25-hydroxyvitamin D, and risk of incident diabetes. The research design and methods were a prospective observational study with a mean follow-up of 2.7 years in the Diabetes Prevention Program (DPP), a multi-center trial co...

[Design of a multicenter study for assessing the effectiveness of extracorporeal shockwave therapy in epicondylitis humeri radialis].

PubMed

Haake, M; Jensen, K; Prinz, H; Willenberg, T

2000-01-01

Previously published studies concerning, extracorporeal shock-wave therapy (ESWT) in the treatment of lateral epicondylitis do not fulfil the biometric standards of modern clinical research. The objective of the trial is to show that ESWT is effective in the treatment of chronic LE. A prospective, randomized, placebo-controlled, single-blinded, multicenter trial with an independent blinded observer was designed. The effectiveness of ESWT is evaluated by comparison with a control group in which sham-ESWT is performed, both under local anaesthesia. Outcome is determined on the basis of the Roles/Maudsley-Score. Inclusion criteria are a history of at least 6 months of LE and failure of conventional treatment. The therapy includes 3 sessions of low energy ESWT with 2000 impulses (energy flux density 0.07-0.09 mJ/mm2). Sample size is 272 patients. Randomisation started in October 1998 and is planned over a period of two and a half years. Only a randomised clinical trial with adequate control of placebo effects and observer bias can provide the required evidence for the efficiency of ESWT in the treatment of lateral epicondylitis of the elbow.

PRotective Effect on the coronary microcirculation of patients with DIabetes by Clopidogrel or Ticagrelor (PREDICT): study rationale and design. A randomized multicenter clinical trial using intracoronary multimodal physiology.

PubMed

Cerrato, Enrico; Quirós, Alicia; Echavarría-Pinto, Mauro; Mejia-Renteria, Hernan; Aldazabal, Andres; Ryan, Nicola; Gonzalo, Nieves; Jimenez-Quevedo, Pilar; Nombela-Franco, Luis; Salinas, Pablo; Núñez-Gil, Iván J; Rumoroso, José Ramón; Fernández-Ortiz, Antonio; Macaya, Carlos; Escaned, Javier

2017-05-19

In diabetic patients a predisposed coronary microcirculation along with a higher risk of distal particulate embolization during primary percutaneous intervention (PCI) increases the risk of peri-procedural microcirculatory damage. However, new antiplatelet agents, in particular Ticagrelor, may protect the microcirculation through its adenosine-mediated vasodilatory effects. PREDICT is an original, prospective, randomized, multicenter controlled study designed to investigate the protective effect of Ticagrelor on the microcirculation during PCI in patient with diabetes mellitus type 2 or pre-diabetic status. The primary endpoints of this study aim to test (i) the decrease in microcirculatory resistance with antiplatelet therapy (Ticagrelor > Clopidogrel; mechanistic effect) and (ii) the relative microcirculatory protection of Ticagrelor compared to Clopidogrel during PCI (Ticagrelor < Clopidogrel; protective effect). PREDICT will be the first multicentre clinical trial to test the adenosine-mediated vasodilatory effect of Ticagrelor on the microcirculation during PCI in diabetic patients. The results will provide important insights into the prospective beneficial effect of this drug in preventing microvascular impairment related to PCI ( http://www.clinicaltrials.gov No. NCT02698618).

Study Design and Rationale of "A Multicenter, Open-Labeled, Randomized Controlled Trial Comparing MIdazolam Versus MOrphine in Acute Pulmonary Edema": MIMO Trial.

PubMed

Dominguez-Rodriguez, Alberto; Burillo-Putze, Guillermo; Garcia-Saiz, Maria Del Mar; Aldea-Perona, Ana; Harmand, Magali González-Colaço; Mirò, Oscar; Abreu-Gonzalez, Pedro

2017-04-01

Morphine has been used for several decades in cases of acute pulmonary edema (APE) due to the anxiolytic and vasodilatory properties of the drug. The non-specific depression of the central nervous system is probably the most significant factor for the changes in hemodynamics in APE. Retrospective studies have shown both negative and neutral effects in patients with APE and therefore some authors have suggested benzodiazepines as an alternative treatment. The use of intravenous morphine in the treatment of APE remains controversial. The MIdazolan versus MOrphine in APE trial (MIMO) is a multicenter, prospective, open-label, randomized study designed to evaluate the efficacy and safety of morphine in patients with APE. The MIMO trial will evaluate as a primary endpoint whether intravenous morphine administration improves clinical outcomes defined as in-hospital mortality. Secondary endpoint evaluation will be mechanical ventilation, cardiopulmonary resuscitation, intensive care unit admission rate, intensive care unit length of stay, and hospitalization length. In the emergency department, morphine is still used for APE in spite of poor scientific background data. The data from the MIMO trial will establish the effect-and especially the risk-when using morphine for APE.

A review of the epidemiological methods used to investigate the health impacts of air pollution around major industrial areas.

PubMed

Pascal, Mathilde; Pascal, Laurence; Bidondo, Marie-Laure; Cochet, Amandine; Sarter, Hélène; Stempfelet, Morgane; Wagner, Vérène

2013-01-01

We performed a literature review to investigate how epidemiological studies have been used to assess the health consequences of living in the vicinity of industries. 77 papers on the chronic effects of air pollution around major industrial areas were reviewed. Major health themes were cancers (27 studies), morbidity (25 studies), mortality (7 studies), and birth outcome (7 studies). Only 3 studies investigated mental health. While studies were available from many different countries, a majority of papers came from the United Kingdom, Italy, and Spain. Several studies were motivated by concerns from the population or by previous observations of an overincidence of cases. Geographical ecological designs were largely used for studying cancer and mortality, including statistical designs to quantify a relationship between health indicators and exposure. Morbidity was frequently investigated through cross-sectional surveys on the respiratory health of children. Few multicenter studies were performed. In a majority of papers, exposed areas were defined based on the distance to the industry and were located from <2 km to >20 km from the plants. Improving the exposure assessment would be an asset to future studies. Criteria to include industries in multicenter studies should be defined.

SNSPD with parallel nanowires (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ejrnaes, Mikkel; Parlato, Loredana; Gaggero, Alessandro; Mattioli, Francesco; Leoni, Roberto; Pepe, Giampiero; Cristiano, Roberto

2017-05-01

Superconducting nanowire single-photon detectors (SNSPDs) have shown to be promising in applications such as quantum communication and computation, quantum optics, imaging, metrology and sensing. They offer the advantages of a low dark count rate, high efficiency, a broadband response, a short time jitter, a high repetition rate, and no need for gated-mode operation. Several SNSPD designs have been proposed in literature. Here, we discuss the so-called parallel nanowires configurations. They were introduced with the aim of improving some SNSPD property like detection efficiency, speed, signal-to-noise ratio, or photon number resolution. Although apparently similar, the various parallel designs are not the same. There is no one design that can improve the mentioned properties all together. In fact, each design presents its own characteristics with specific advantages and drawbacks. In this work, we will discuss the various designs outlining peculiarities and possible improvements.

Algorithms for the Construction of Parallel Tests by Zero-One Programming. Project Psychometric Aspects of Item Banking No. 7. Research Report 86-7.

ERIC Educational Resources Information Center

Boekkooi-Timminga, Ellen

Nine methods for automated test construction are described. All are based on the concepts of information from item response theory. Two general kinds of methods for the construction of parallel tests are presented: (1) sequential test design; and (2) simultaneous test design. Sequential design implies that the tests are constructed one after the…

Design and implementation of a novel modal space active force control concept for spatial multi-DOF parallel robotic manipulators actuated by electrical actuators.

PubMed

Yang, Chifu; Zhao, Jinsong; Li, Liyi; Agrawal, Sunil K

2018-01-01

Robotic spine brace based on parallel-actuated robotic system is a new device for treatment and sensing of scoliosis, however, the strong dynamic coupling and anisotropy problem of parallel manipulators result in accuracy loss of rehabilitation force control, including big error in direction and value of force. A novel active force control strategy named modal space force control is proposed to solve these problems. Considering the electrical driven system and contact environment, the mathematical model of spatial parallel manipulator is built. The strong dynamic coupling problem in force field is described via experiments as well as the anisotropy problem of work space of parallel manipulators. The effects of dynamic coupling on control design and performances are discussed, and the influences of anisotropy on accuracy are also addressed. With mass/inertia matrix and stiffness matrix of parallel manipulators, a modal matrix can be calculated by using eigenvalue decomposition. Making use of the orthogonality of modal matrix with mass matrix of parallel manipulators, the strong coupled dynamic equations expressed in work space or joint space of parallel manipulator may be transformed into decoupled equations formulated in modal space. According to this property, each force control channel is independent of others in the modal space, thus we proposed modal space force control concept which means the force controller is designed in modal space. A modal space active force control is designed and implemented with only a simple PID controller employed as exampled control method to show the differences, uniqueness, and benefits of modal space force control. Simulation and experimental results show that the proposed modal space force control concept can effectively overcome the effects of the strong dynamic coupling and anisotropy problem in the physical space, and modal space force control is thus a very useful control framework, which is better than the current joint space control and work space control. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

A Randomized, Double-blind, Vehicle-controlled Trial of Luliconazole Cream 1% in the Treatment of Interdigital Tinea Pedis

PubMed Central

Vlahovic, Tracey C.; Gold, Michael H.; Parish, Lawrence Charles; Korotzer, Andrew

2014-01-01

Objective: To evaluate the efficacy and safety of luliconazole cream 1% applied once daily for 14 days in patients with interdigital tinea pedis. Design: Multicenter, randomized, double-blind, parallel-group, vehicle-controlled study. Setting: Private dermatology clinics and clinical research centers in the United States and Central America. Participants: Three hundred twenty-two male and female patients ≥12 years of age diagnosed with interdigital tinea pedis. Measurements: Complete clearance (i.e., clinical and mycological cure), effective treatment, and fungal culture and susceptibility. Results: At study Day 42, complete clearance was obtained by a larger percentage (14.0% [15/107] vs. 2.8% [3/107]; p<0.001) of patients treated with luliconazole cream 1% compared with vehicle. Also at Day 42, more luliconazole-treated patients compared with vehicle-treated patients obtained effective treatment (32.7% vs. 15.0%), clinical cure (15.0% vs. 3.7%), and mycologic cure (56.1% vs. 27.1%). Erythema, scaling, and pruritus scores were lower for the luliconazole cream 1% group compared with vehicle on Day 14, Day 28, and Day 42. For all species and the same isolates, the MIC50/90 for luliconazole cream 1% was 6- to 12-fold lower than for other agents tested. No patients discontinued treatment because of a treatment-emergent adverse event. Conclusion: Luliconazole cream 1% was safe and well-tolerated and demonstrated significantly greater efficacy than vehicle cream in patients with interdigital tinea pedis. PMID:25371767

Variability of indoor fungal microbiome of green and non-green low-income homes in Cincinnati, Ohio.

PubMed

Coombs, Kanistha; Taft, Diana; Ward, Doyle V; Green, Brett J; Chew, Ginger L; Shamsaei, Behrouz; Meller, Jaroslaw; Indugula, Reshmi; Reponen, Tiina

2018-01-01

"Green" housing is designed to use low-impact materials, increase energy efficiency and improve occupant health. However, little is known about the indoor mycobiome of green homes. The current study is a subset of a multicenter study that aims to investigate the indoor environment of green homes and the respiratory health of asthmatic children. In the current study, the mycobiome in air, bed dust and floor dust was compared between green (study site) and non-green (control site), low-income homes in Cincinnati, Ohio. The samples were collected at baseline (within four months following renovation), and 12months after the baseline at the study site. Parallel sample collection was conducted in non-green control homes. Air samples were collected by PM2.5 samplers over 5-days. Bed and floor dust samples were vacuumed after the air sampling was completed. The DNA sample extracts were analyzed using ITS amplicon sequencing. Analysis indicated that there was no clear trend in the fungal communities between green and non-green homes. Instead, fungal community differences were greatest between sample types - air, bed, and floor. Microbial communities also changed substantially between sampling intervals in both green and non-green homes for all sample types, potentially indicating that there was very little stability in the mycobiomes. Research gaps remain regarding how indoor mycobiome fluctuates over time. Longer follow-up periods might elucidate the effect of green renovation on microbial load in buildings. Copyright © 2017 Elsevier B.V. All rights reserved.

The Aspirin Regimens in Essential Thrombocythemia (ARES) phase II randomized trial design: Implementation of the serum thromboxane B2 assay as an evaluation tool of different aspirin dosing regimens in the clinical setting.

PubMed

De Stefano, Valerio; Rocca, Bianca; Tosetto, Alberto; Soldati, Denise; Petrucci, Giovanna; Beggiato, Eloise; Bertozzi, Irene; Betti, Silvia; Carli, Giuseppe; Carpenedo, Monica; Cattaneo, Daniele; Cavalca, Viviana; Dragani, Alfredo; Elli, Elena; Finazzi, Guido; Iurlo, Alessandra; Lanzarone, Giuseppe; Lissandrini, Laura; Palandri, Francesca; Paoli, Chiara; Rambaldi, Alessandro; Ranalli, Paola; Randi, Maria Luigia; Ricco, Alessandra; Rossi, Elena; Ruggeri, Marco; Specchia, Giorgina; Timillero, Andrea; Turnu, Linda; Vianelli, Nicola; Vannucchi, Alessandro M; Rodeghiero, Francesco; Patrono, Carlo

2018-06-01

Once-daily (od), low-dose aspirin (75-100 mg) is recommended to reduce the thrombotic risk of patients with essential thrombocytemia (ET). This practice is based on data extrapolated from other high-risk patients and an aspirin trial in polycythemia vera, with the assumption of similar aspirin pharmacodynamics in the two settings. However, the pharmacodynamics of low-dose aspirin is impaired in ET, reflecting accelerated renewal of platelet cyclooxygenase (COX)-1. ARES is a parallel-arm, placebo-controlled, randomized, dose-finding, phase II trial enrolling 300 ET patients to address two main questions. First, whether twice or three times 100 mg aspirin daily dosing is superior to the standard od regimen in inhibiting platelet thromboxane (TX)A 2 production, without inhibiting vascular prostacyclin biosynthesis. Second, whether long-term persistence of superior biochemical efficacy can be safely maintained with multiple vs. single dosing aspirin regimen. Considering that the primary study end point is serum TXB 2 , a surrogate biomarker of clinical efficacy, a preliminary exercise of reproducibility and validation of this biomarker across all the 11 participating centers was implemented. The results of this preliminary phase demonstrate the importance of controlling reproducibility of biomarkers in multicenter trials and the feasibility of using serum TXB 2 as a reliable end point for dose-finding studies of novel aspirin regimens.

Safety and Tolerability of Panax ginseng Root Extract: A Randomized, Placebo-Controlled, Clinical Trial in Healthy Korean Volunteers

PubMed Central

Lee, Nam-Hun; Yoo, Sa-Ra; Kim, Hyeong-Geug; Cho, Jung-Hyo

2012-01-01

Abstract Objectives Panax ginseng has been extensively used as an adaptogen and is among the top 10 selling herbal supplements in the United States over the past decade. However, there have been few reports about the toxicity of P. ginseng in human studies. Given the lack of toxicological studies in human, this study investigated whether P. ginseng administration causes any noticeable toxic effects in healthy volunteers. Methods This study was designed as a randomized, double-blind, placebo-controlled, and parallel group trial in healthy volunteers. The subjects were required to be healthy, free from any significant disease, as assessed at screening by physical examination, medical history, and laboratory (hematological and biochemical) tests. Eligible subjects received P. ginseng extract (1 g/day or 2 g/day) or placebo over a 4-week period. Results Although mild adverse events, such as dyspepsia, hot flash, insomnia, and constipation, were reported in both P. ginseng and placebo group, no serious untoward reactions were reported following P. ginseng administration. Nonsignificant changes were observed in hematological and biochemical tests. Conclusions P. ginseng administration for 4 weeks was shown to be safe, tolerable, and free of any untoward toxic effect in healthy male and female volunteers. Future results from ongoing multicenter collaborative efforts to evaluate short- and long-term effects of P. ginseng may contribute to our current understanding of safety and tolerability of this herbal product. PMID:22909282

Design of object-oriented distributed simulation classes

NASA Technical Reports Server (NTRS)

Schoeffler, James D. (Principal Investigator)

1995-01-01

Distributed simulation of aircraft engines as part of a computer aided design package is being developed by NASA Lewis Research Center for the aircraft industry. The project is called NPSS, an acronym for 'Numerical Propulsion Simulation System'. NPSS is a flexible object-oriented simulation of aircraft engines requiring high computing speed. It is desirable to run the simulation on a distributed computer system with multiple processors executing portions of the simulation in parallel. The purpose of this research was to investigate object-oriented structures such that individual objects could be distributed. The set of classes used in the simulation must be designed to facilitate parallel computation. Since the portions of the simulation carried out in parallel are not independent of one another, there is the need for communication among the parallel executing processors which in turn implies need for their synchronization. Communication and synchronization can lead to decreased throughput as parallel processors wait for data or synchronization signals from other processors. As a result of this research, the following have been accomplished. The design and implementation of a set of simulation classes which result in a distributed simulation control program have been completed. The design is based upon MIT 'Actor' model of a concurrent object and uses 'connectors' to structure dynamic connections between simulation components. Connectors may be dynamically created according to the distribution of objects among machines at execution time without any programming changes. Measurements of the basic performance have been carried out with the result that communication overhead of the distributed design is swamped by the computation time of modules unless modules have very short execution times per iteration or time step. An analytical performance model based upon queuing network theory has been designed and implemented. Its application to realistic configurations has not been carried out.

Design of Object-Oriented Distributed Simulation Classes

NASA Technical Reports Server (NTRS)

Schoeffler, James D.

1995-01-01

Distributed simulation of aircraft engines as part of a computer aided design package being developed by NASA Lewis Research Center for the aircraft industry. The project is called NPSS, an acronym for "Numerical Propulsion Simulation System". NPSS is a flexible object-oriented simulation of aircraft engines requiring high computing speed. It is desirable to run the simulation on a distributed computer system with multiple processors executing portions of the simulation in parallel. The purpose of this research was to investigate object-oriented structures such that individual objects could be distributed. The set of classes used in the simulation must be designed to facilitate parallel computation. Since the portions of the simulation carried out in parallel are not independent of one another, there is the need for communication among the parallel executing processors which in turn implies need for their synchronization. Communication and synchronization can lead to decreased throughput as parallel processors wait for data or synchronization signals from other processors. As a result of this research, the following have been accomplished. The design and implementation of a set of simulation classes which result in a distributed simulation control program have been completed. The design is based upon MIT "Actor" model of a concurrent object and uses "connectors" to structure dynamic connections between simulation components. Connectors may be dynamically created according to the distribution of objects among machines at execution time without any programming changes. Measurements of the basic performance have been carried out with the result that communication overhead of the distributed design is swamped by the computation time of modules unless modules have very short execution times per iteration or time step. An analytical performance model based upon queuing network theory has been designed and implemented. Its application to realistic configurations has not been carried out.

A Generic Mesh Data Structure with Parallel Applications

ERIC Educational Resources Information Center

Cochran, William Kenneth, Jr.

2009-01-01

High performance, massively-parallel multi-physics simulations are built on efficient mesh data structures. Most data structures are designed from the bottom up, focusing on the implementation of linear algebra routines. In this thesis, we explore a top-down approach to design, evaluating the various needs of many aspects of simulation, not just…

Sequential color video to parallel color video converter

NASA Technical Reports Server (NTRS)

1975-01-01

The engineering design, development, breadboard fabrication, test, and delivery of a breadboard field sequential color video to parallel color video converter is described. The converter was designed for use onboard a manned space vehicle to eliminate a flickering TV display picture and to reduce the weight and bulk of previous ground conversion systems.

Multicenter clinical trials in sepsis: understanding the big picture and building a successful operation at your hospital.

PubMed

Dellinger, R Phillip; Schorr, Christa; Trzeciak, Stephen

2011-03-01

Only through adequately designed and adequately conducted clinical trials can new treatments be found for the benefit of the septic patient. Over the past 20 years, tens of thousands of patients have been enrolled in sepsis clinical trials with little success. These efforts, however, have not been without worth. Much has been learned and the knowledge gained has changed our approach to trial design in this very difficult field. Animal studies are better designed to match the clinical picture of severe sepsis. Phase II studies are more carefully engineered to answer questions about the most suitable target population and end points. Trial conduct likely benefits from use of CROs and a CCC. The future of clinical trials may include more standardization of sepsis management across investigative sites. Before the decision is made to become an investigative site in a multicenter industry-sponsored clinical trial in sepsis or severe sepsis, it is important to recognize what is required to succeed. Once these key-to-success elements are in place, members of the investigative team are more likely to realize the satisfaction and career growth from becoming a successful site. The most professional satisfaction comes from the knowledge of contributing to original science in the field of the sepsis. Copyright © 2011 Elsevier Inc. All rights reserved.

The Effectiveness of Parent Training as a Treatment for Preschool Attention-Deficit/Hyperactivity Disorder: Study Protocol for a Randomized Controlled, Multicenter Trial of the New Forest Parenting Program in Everyday Clinical Practice

PubMed Central

Daley, David; Frydenberg, Morten; Rask, Charlotte U; Sonuga-Barke, Edmund; Thomsen, Per H

2016-01-01

Background Parent training is recommended as the first-line treatment for attention-deficit/hyperactivity disorder (ADHD) in preschool children. The New Forest Parenting Programme (NFPP) is an evidence-based parenting program developed specifically to target preschool ADHD. Objective The objective of this trial is to investigate whether the NFPP can be effectively delivered for children referred through official community pathways in everyday clinical practice. Methods A multicenter randomized controlled parallel arm trial design is employed. There are two treatment arms, NFPP and treatment as usual. NFPP consists of eight individually delivered parenting sessions, where the child attends during three of the sessions. Outcomes are examined at three time points (T1, T2, T3): T1 (baseline), T2 (week 12, post intervention), and T3 (6 month follow/up). 140 children between the ages of 3-7, with a clinical diagnosis of ADHD, informed by the Development and Well Being Assessment, and recruited from three child and adolescent psychiatry departments in Denmark will take part. Randomization is on a 1:1 basis, stratified for age and gender. Results The primary endpoint is change in ADHD symptoms as measured by the Preschool ADHD-Rating Scale (ADHD-RS) by T2. Secondary outcome measures include: effects on this measure at T3 and T2 and T3 measures of teacher reported Preschool ADHD-RS scores, parent and teacher rated scores on the Strength & Difficulties Questionnaire, direct observation of ADHD behaviors during Child’s Solo Play, observation of parent-child interaction, parent sense of competence, and family stress. Results will be reported using the standards set out in the Consolidated Standards of Reporting Trials Statement for Randomized Controlled Trials of nonpharmacological treatments. Conclusions The trial will provide evidence as to whether NFPP is a more effective treatment for preschool ADHD than the treatment usually offered in everyday clinical practice. Trial Registration ClinicalTrials.gov NCT01684644; https://clinicaltrials.gov/ct2/show/NCT01684644?term= NCT01684644&rank=1 (Archived by WebCite at http://www.webcitation/6eOOAe8Qe) PMID:27076496

COMplex Fracture Orthopedic Rehabilitation (COMFORT) - Real-time visual biofeedback on weight bearing versus standard training methods in the treatment of proximal femur fractures in the elderly: study protocol for a multicenter randomized controlled trial.

PubMed

Raaben, Marco; Redzwan, Syaiful; Augustine, Robin; Blokhuis, Taco Johan

2018-04-12

Proximal femur fractures are a common injury after low energy trauma in the elderly. Most rehabilitation programs are based on restoring mobility and early resumption of weight-bearing. However, therapy compliance is low in patients following lower extremity fractures. Moreover, little is known about the relevance of gait parameters and how to steer the rehabilitation after proximal femur fractures in the elderly. Therefore, the aim of this prospective, randomized controlled trial is to gain insight in gait parameters and evaluate if real-time visual biofeedback can improve therapy compliance after proximal femur fractures in the elderly. This is a two-arm, parallel-design, prospective, randomized controlled trial. Inclusion criteria are age ≥ 60 years, a proximal femur fracture following low energy trauma, and unrestricted-weight bearing. Exclusion criteria are cognitive impairment and limited mobility before trauma. Participants are randomized into either the control group, which receives care as usual, or the intervention group, which receives real-time visual biofeedback about weight-bearing during gait in addition to care as usual. Spatiotemporal gait parameters will be measured in 94 participants per group during a 30-m walk with an ambulatory biofeedback system (SensiStep). The progress of rehabilitation will be evaluated by the primary outcome parameters maximum peak load and step duration in relation to the discharge date. Secondary outcome parameters include other spatiotemporal gait parameters in relation to discharge date. Furthermore, the gait parameters will be related to three validated clinical tests: Elderly Mobility Scale; Functional Ambulation Categories; and Visual Analogue Scale. The primary hypothesis is that participants in the intervention group will show improved and faster rehabilitation compared to the control group. The first aim of this multicenter trial is to investigate the normal gait patterns after proximal femur fractures in the elderly. The use of biofeedback systems during rehabilitation after proximal femur fractures in the elderly is promising; therefore, the second aim is to investigate the effect of real-time visual biofeedback on gait after proximal femur fractures in the elderly. This could lead to improved outcome. In addition, analysis of the population may indicate characteristics of subgroups that benefit from feedback, making a differentiated approach in rehabilitation strategy possible. TrialRegister.nl, NTR6794 . Registered on 31 October 2017.

Prevention of violent revictimization in depressed patients with an add-on internet-based emotion regulation training (iERT): study protocol for a multicenter randomized controlled trial.

PubMed

Christ, Carolien; de Waal, Marleen M; van Schaik, Digna J F; Kikkert, Martijn J; Blankers, Matthijs; Bockting, Claudi L H; Beekman, Aartjan T F; Dekker, Jack J M

2018-02-02

Psychiatric patients are at high risk of becoming victim of a violent crime compared to the general population. Although most research has focused on patients with severe mental illness, depressed patients have been demonstrated to be prone to victimization as well. Victimization is associated with more severe symptomatology, decreased quality of life, and high risk of revictimization. Hence, there is a strong need for interventions that focus on preventing violent revictimization. Since emotion dysregulation is associated with both victimization and depression, we developed an internet-based Emotion Regulation Training (iERT) to reduce revictimization in depressed patients. This study aims to evaluate the clinical and cost-effectiveness of iERT added to Treatment As Usual (TAU) in reducing incidents of violent revictimization among depressed patients with a recent history of victimization. Furthermore, this study aims to examine secondary clinical outcomes, and moderators and mediators that may be associated with treatment outcomes. In a multicenter randomized controlled trial with parallel group design, patients with a major depressive disorder and a history of violent victimization over the past three years (N = 200) will be allocated to either TAU + iERT (N = 100) or TAU only (N = 100), based on computer-generated stratified block randomization. Assessments will take place at baseline, 8 weeks, 14 weeks, and 6 months after start of treatment, and 12, 24, and 36 months after baseline. The primary outcome measure is the total number of violent victimization incidents at 12 months after baseline, measured with the Safety Monitor: an adequate self-report questionnaire that assesses victimization over the preceding 12 months. Secondary outcome measures and mediators include emotion dysregulation and depressive symptomatology. An economic evaluation with the societal perspective will be performed alongside the trial. This study is the first to examine the effectiveness of an intervention aimed at reducing violent revictimization in depressed patients. If effective, iERT can be implemented in mental health care, and contribute to the well-being of depressed patients. Furthermore, the results will provide insight into underlying mechanisms of revictimization. The study is registered at the Netherlands Trial Register ( NTR5822 ). Date of registration: 4 April 2016.

Parallel Architectures and Parallel Algorithms for Integrated Vision Systems. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Choudhary, Alok Nidhi

1989-01-01

Computer vision is regarded as one of the most complex and computationally intensive problems. An integrated vision system (IVS) is a system that uses vision algorithms from all levels of processing to perform for a high level application (e.g., object recognition). An IVS normally involves algorithms from low level, intermediate level, and high level vision. Designing parallel architectures for vision systems is of tremendous interest to researchers. Several issues are addressed in parallel architectures and parallel algorithms for integrated vision systems.

Quantitative high-efficiency cadmium-zinc-telluride SPECT with dedicated parallel-hole collimation system in obese patients: results of a multi-center study.

PubMed

Nakazato, Ryo; Slomka, Piotr J; Fish, Mathews; Schwartz, Ronald G; Hayes, Sean W; Thomson, Louise E J; Friedman, John D; Lemley, Mark; Mackin, Maria L; Peterson, Benjamin; Schwartz, Arielle M; Doran, Jesse A; Germano, Guido; Berman, Daniel S

2015-04-01

Obesity is a common source of artifact on conventional SPECT myocardial perfusion imaging (MPI). We evaluated image quality and diagnostic performance of high-efficiency (HE) cadmium-zinc-telluride parallel-hole SPECT MPI for coronary artery disease (CAD) in obese patients. 118 consecutive obese patients at three centers (BMI 43.6 ± 8.9 kg·m(-2), range 35-79.7 kg·m(-2)) had upright/supine HE-SPECT and invasive coronary angiography > 6 months (n = 67) or low likelihood of CAD (n = 51). Stress quantitative total perfusion deficit (TPD) for upright (U-TPD), supine (S-TPD), and combined acquisitions (C-TPD) was assessed. Image quality (IQ; 5 = excellent; < 3 nondiagnostic) was compared among BMI 35-39.9 (n = 58), 40-44.9 (n = 24) and ≥45 (n = 36) groups. ROC curve area for CAD detection (≥50% stenosis) for U-TPD, S-TPD, and C-TPD were 0.80, 0.80, and 0.87, respectively. Sensitivity/specificity was 82%/57% for U-TPD, 74%/71% for S-TPD, and 80%/82% for C-TPD. C-TPD had highest specificity (P = .02). C-TPD normalcy rate was higher than U-TPD (88% vs 75%, P = .02). Mean IQ was similar among BMI 35-39.9, 40-44.9 and ≥45 groups [4.6 vs 4.4 vs 4.5, respectively (P = .6)]. No patient had a nondiagnostic stress scan. In obese patients, HE-SPECT MPI with dedicated parallel-hole collimation demonstrated high image quality, normalcy rate, and diagnostic accuracy for CAD by quantitative analysis of combined upright/supine acquisitions.

Quantitative High-Efficiency Cadmium-Zinc-Telluride SPECT with Dedicated Parallel-Hole Collimation System in Obese Patients: Results of a Multi-Center Study

PubMed Central

Nakazato, Ryo; Slomka, Piotr J.; Fish, Mathews; Schwartz, Ronald G.; Hayes, Sean W.; Thomson, Louise E.J.; Friedman, John D.; Lemley, Mark; Mackin, Maria L.; Peterson, Benjamin; Schwartz, Arielle M.; Doran, Jesse A.; Germano, Guido; Berman, Daniel S.

2014-01-01

Background Obesity is a common source of artifact on conventional SPECT myocardial perfusion imaging (MPI). We evaluated image quality and diagnostic performance of high-efficiency (HE) cadmium-zinc-telluride (CZT) parallel-hole SPECT-MPI for coronary artery disease (CAD) in obese patients. Methods and Results 118 consecutive obese patients at 3 centers (BMI 43.6±8.9 kg/m2, range 35–79.7 kg/m2) had upright/supine HE-SPECT and ICA >6 months (n=67) or low-likelihood of CAD (n=51). Stress quantitative total perfusion deficit (TPD) for upright (U-TPD), supine (S-TPD) and combined acquisitions (C-TPD) was assessed. Image quality (IQ; 5=excellent; <3 nondiagnostic) was compared among BMI 35–39.9 (n=58), 40–44.9 (n=24) and ≥45 (n=36) groups. ROC-curve area for CAD detection (≥50% stenosis) for U-TPD, S-TPD, and C-TPD were 0.80, 0.80, and 0.87, respectively. Sensitivity/specificity was 82%/57% for U-TPD, 74%/71% for S-TPD, and 80%/82% for C-TPD. C-TPD had highest specificity (P=.02). C-TPD normalcy rate was higher than U-TPD (88% vs. 75%, P=.02). Mean IQ was similar among BMI 35–39.9, 40–44.9 and ≥45 groups [4.6 vs. 4.4 vs. 4.5, respectively (P=.6)]. No patient had a non-diagnostic stress scan. Conclusions In obese patients, HE-SPECT MPI with dedicated parallel-hole collimation demonstrated high image quality, normalcy rate, and diagnostic accuracy for CAD by quantitative analysis of combined upright/supine acquisitions. PMID:25388380

An embedded multi-core parallel model for real-time stereo imaging

NASA Astrophysics Data System (ADS)

He, Wenjing; Hu, Jian; Niu, Jingyu; Li, Chuanrong; Liu, Guangyu

2018-04-01

The real-time processing based on embedded system will enhance the application capability of stereo imaging for LiDAR and hyperspectral sensor. The task partitioning and scheduling strategies for embedded multiprocessor system starts relatively late, compared with that for PC computer. In this paper, aimed at embedded multi-core processing platform, a parallel model for stereo imaging is studied and verified. After analyzing the computing amount, throughout capacity and buffering requirements, a two-stage pipeline parallel model based on message transmission is established. This model can be applied to fast stereo imaging for airborne sensors with various characteristics. To demonstrate the feasibility and effectiveness of the parallel model, a parallel software was designed using test flight data, based on the 8-core DSP processor TMS320C6678. The results indicate that the design performed well in workload distribution and had a speed-up ratio up to 6.4.

Displacement and deformation measurement for large structures by camera network

NASA Astrophysics Data System (ADS)

Shang, Yang; Yu, Qifeng; Yang, Zhen; Xu, Zhiqiang; Zhang, Xiaohu

2014-03-01

A displacement and deformation measurement method for large structures by a series-parallel connection camera network is presented. By taking the dynamic monitoring of a large-scale crane in lifting operation as an example, a series-parallel connection camera network is designed, and the displacement and deformation measurement method by using this series-parallel connection camera network is studied. The movement range of the crane body is small, and that of the crane arm is large. The displacement of the crane body, the displacement of the crane arm relative to the body and the deformation of the arm are measured. Compared with a pure series or parallel connection camera network, the designed series-parallel connection camera network can be used to measure not only the movement and displacement of a large structure but also the relative movement and deformation of some interesting parts of the large structure by a relatively simple optical measurement system.

The effect of cell design and test criteria on the series/parallel performance of nickel cadmium cells and batteries

NASA Technical Reports Server (NTRS)

Halpert, G.; Webb, D. A.

1983-01-01

Three batteries were operated in parallel from a common bus during charge and discharge. SMM utilized NASA Standard 20AH cells and batteries, and LANDSAT-D NASA 50AH cells and batteries of a similar design. Each battery consisted of 22 series connected cells providing the nominal 28V bus. The three batteries were charged in parallel using the voltage limit/current taper mode wherein the voltage limit was temperature compensated. Discharge occurred on the demand of the spacecraft instruments and electronics. Both flights were planned for three to five year missions. The series/parallel configuration of cells and batteries for the 3-5 yr mission required a well controlled product with built-in reliability and uniformity. Examples of how component, cell and battery selection methods affect the uniformity of the series/parallel operation of the batteries both in testing and in flight are given.

The impact of written information and counseling (WOMAN-PRO II Program) on symptom outcomes in women with vulvar neoplasia: A multicenter randomized controlled phase II study.

PubMed

Raphaelis, Silvia; Mayer, Hanna; Ott, Stefan; Mueller, Michael D; Steiner, Enikö; Joura, Elmar; Senn, Beate

2017-07-01

To determine whether written information and/or counseling based on the WOMAN-PRO II Program decreases symptom prevalence in women with vulvar neoplasia by a clinically relevant degree, and to explore the differences between the 2 interventions in symptom prevalence, symptom distress prevalence, and symptom experience. A multicenter randomized controlled parallel-group phase II trial with 2 interventions provided to patients after the initial diagnosis was performed in Austria and Switzerland. Women randomized to written information received a predefined set of leaflets concerning wound care and available healthcare services. Women allocated to counseling were additionally provided with 5 consultations by an Advanced Practice Nurse (APN) between the initial diagnosis and 6months post-surgery that focused on symptom management, utilization of healthcare services, and health-related decision-making. Symptom outcomes were simultaneously measured 5 times to the counseling time points. A total of 49 women with vulvar neoplasia participated in the study. Symptom prevalence decreased in women with counseling by a clinically relevant degree, but not in women with written information. Sporadically, significant differences between the 2 interventions could be observed in individual items, but not in the total scales or subscales of the symptom outcomes. The results indicate that counseling may reduce symptom prevalence in women with vulvar neoplasia by a clinically relevant extent. The observed group differences between the 2 interventions slightly favor counseling over written information. The results justify testing the benefit of counseling thoroughly in a comparative phase III trial. Copyright © 2017 Elsevier Inc. All rights reserved.

A multi-center randomized controlled trial to compare a self-ligating bracket with a conventional bracket in a UK population: Part 1: Treatment efficiency.

PubMed

O'Dywer, Lian; Littlewood, Simon J; Rahman, Shahla; Spencer, R James; Barber, Sophy K; Russell, Joanne S

2016-01-01

To use a two-arm parallel trial to compare treatment efficiency between a self-ligating and a conventional preadjusted edgewise appliance system. A prospective multi-center randomized controlled clinical trial was conducted in three hospital orthodontic departments. Subjects were randomly allocated to receive treatment with either a self-ligating (3M SmartClip) or conventional (3M Victory) preadjusted edgewise appliance bracket system using a computer-generated random sequence concealed in opaque envelopes, with stratification for operator and center. Two operators followed a standardized protocol regarding bracket bonding procedure and archwire sequence. Efficiency of each ligation system was assessed by comparing the duration of treatment (months), total number of appointments (scheduled and emergency visits), and number of bracket bond failures. One hundred thirty-eight subjects (mean age 14 years 11 months) were enrolled in the study, of which 135 subjects (97.8%) completed treatment. The mean treatment time and number of visits were 25.12 months and 19.97 visits in the SmartClip group and 25.80 months and 20.37 visits in the Victory group. The overall bond failure rate was 6.6% for the SmartClip and 7.2% for Victory, with a similar debond distribution between the two appliances. No significant differences were found between the bracket systems in any of the outcome measures. No serious harm was observed from either bracket system. There was no clinically significant difference in treatment efficiency between treatment with a self-ligating bracket system and a conventional ligation system.

A multicenter, randomized controlled trial comparing the identification rate of stigmata of recent hemorrhage and rebleeding rate between early and elective colonoscopy in outpatient-onset acute lower gastrointestinal bleeding: study protocol for a randomized controlled trial.

PubMed

Niikura, Ryota; Nagata, Naoyoshi; Yamada, Atsuo; Doyama, Hisashi; Shiratori, Yasutoshi; Nishida, Tsutomu; Kiyotoki, Shu; Yada, Tomoyuki; Fujita, Tomoki; Sumiyoshi, Tetsuya; Hasatani, Kenkei; Mikami, Tatsuya; Honda, Tetsuro; Mabe, Katsuhiro; Hara, Kazuo; Yamamoto, Katsumi; Takeda, Mariko; Takata, Munenori; Tanaka, Mototsugu; Shinozaki, Tomohiro; Fujishiro, Mitsuhiro; Koike, Kazuhiko

2018-04-03

The clinical benefit of early colonoscopy within 24 h of arrival in patients with severe acute lower gastrointestinal bleeding (ALGIB) remains controversial. This trial will compare early colonoscopy (performed within 24 h) versus elective colonoscopy (performed between 24 and 96 h) to examine the identification rate of stigmata of recent hemorrhage (SRH) in ALGIB patients. We hypothesize that, compared with elective colonoscopy, early colonoscopy increases the identification of SRH and subsequently improves clinical outcomes. This trial is an investigator-initiated, multicenter, randomized, open-label, parallel-group trial examining the superiority of early colonoscopy over elective colonoscopy (standard therapy) in ALGIB patients. The primary outcome measure is the identification of SRH. Secondary outcomes include 30-day rebleeding, success of endoscopic treatment, need for additional endoscopic examination, need for interventional radiology, need for surgery, need for transfusion during hospitalization, length of stay, 30-day thrombotic events, 30-day mortality, preparation-related adverse events, and colonoscopy-related adverse events. The sample size will enable detection of a 9% SRH rate in elective colonoscopy patients and a SRH rate of ≥ 26% in early colonoscopy patients with a risk of type I error of 5% and a power of 80%. This trial will provide high-quality data on the benefits and risks of early colonoscopy in ALGIB patients. UMIN-CTR Identifier, UMIN000021129 . Registered on 21 February 2016; ClinicalTrials.gov Identifier, NCT03098173 . Registered on 24 March 2017.

Performance analysis of parallel branch and bound search with the hypercube architecture

NASA Technical Reports Server (NTRS)

Mraz, Richard T.

1987-01-01

With the availability of commercial parallel computers, researchers are examining new classes of problems which might benefit from parallel computing. This paper presents results of an investigation of the class of search intensive problems. The specific problem discussed is the Least-Cost Branch and Bound search method of deadline job scheduling. The object-oriented design methodology was used to map the problem into a parallel solution. While the initial design was good for a prototype, the best performance resulted from fine-tuning the algorithm for a specific computer. The experiments analyze the computation time, the speed up over a VAX 11/785, and the load balance of the problem when using loosely coupled multiprocessor system based on the hypercube architecture.

Architecture design of a generic centralized adjudication module integrated in a web-based clinical trial management system

PubMed Central

Zhao, Wenle; Pauls, Keith

2015-01-01

Background Centralized outcome adjudication has been used widely in multi-center clinical trials in order to prevent potential biases and to reduce variations in important safety and efficacy outcome assessments. Adjudication procedures could vary significantly among different studies. In practice, the coordination of outcome adjudication procedures in many multicenter clinical trials remains as a manual process with low efficiency and high risk of delay. Motivated by the demands from two large clinical trial networks, a generic outcome adjudication module has been developed by the network’s data management center within a homegrown clinical trial management system. In this paper, the system design strategy and database structure are presented. Methods A generic database model was created to transfer different adjudication procedures into a unified set of sequential adjudication steps. Each adjudication step was defined by one activate condition, one lock condition, one to five categorical data items to capture adjudication results, and one free text field for general comments. Based on this model, a generic outcome adjudication user interface and a generic data processing program were developed within a homegrown clinical trial management system to provide automated coordination of outcome adjudication. Results By the end of 2014, this generic outcome adjudication module had been implemented in 10 multicenter trials. A total of 29 adjudication procedures were defined with the number of adjudication steps varying from 1 to 7. The implementation of a new adjudication procedure in this generic module took an experienced programmer one or two days. A total of 7,336 outcome events had been adjudicated and 16,235 adjudication step activities had been recorded. In a multicenter trial, 1144 safety outcome event submissions went through a three-step adjudication procedure and reported a median of 3.95 days from safety event case report form submission to adjudication completion. In another trial, 277 clinical outcome events were adjudicated by a six-step procedure and took a median of 23.84 days from outcome event case report form submission to adjudication procedure completion. Conclusions A generic outcome adjudication module integrated in the clinical trial management system made the automated coordination of efficacy and safety outcome adjudication a reality. PMID:26464429

Scalable descriptive and correlative statistics with Titan.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, David C.; Pebay, Philippe Pierre

This report summarizes the existing statistical engines in VTK/Titan and presents the parallel versions thereof which have already been implemented. The ease of use of these parallel engines is illustrated by the means of C++ code snippets. Furthermore, this report justifies the design of these engines with parallel scalability in mind; then, this theoretical property is verified with test runs that demonstrate optimal parallel speed-up with up to 200 processors.

The Design and Evaluation of "CAPTools"--A Computer Aided Parallelization Toolkit

NASA Technical Reports Server (NTRS)

Yan, Jerry; Frumkin, Michael; Hribar, Michelle; Jin, Haoqiang; Waheed, Abdul; Johnson, Steve; Cross, Jark; Evans, Emyr; Ierotheou, Constantinos; Leggett, Pete;

A design concept of parallel elasticity extracted from biological muscles for engineered actuators.

PubMed

Chen, Jie; Jin, Hongzhe; Iida, Fumiya; Zhao, Jie

2016-08-23

Series elastic actuation that takes inspiration from biological muscle-tendon units has been extensively studied and used to address the challenges (e.g. energy efficiency, robustness) existing in purely stiff robots. However, there also exists another form of passive property in biological actuation, parallel elasticity within muscles themselves, and our knowledge of it is limited: for example, there is still no general design strategy for the elasticity profile. When we look at nature, on the other hand, there seems a universal agreement in biological systems: experimental evidence has suggested that a concave-upward elasticity behaviour is exhibited within the muscles of animals. Seeking to draw possible design clues for elasticity in parallel with actuators, we use a simplified joint model to investigate the mechanisms behind this biologically universal preference of muscles. Actuation of the model is identified from general biological joints and further reduced with a specific focus on muscle elasticity aspects, for the sake of easy implementation. By examining various elasticity scenarios, one without elasticity and three with elasticity of different profiles, we find that parallel elasticity generally exerts contradictory influences on energy efficiency and disturbance rejection, due to the mechanical impedance shift thus caused. The trade-off analysis between them also reveals that concave parallel elasticity is able to achieve a more advantageous balance than linear and convex ones. It is expected that the results could contribute to our further understanding of muscle elasticity and provide a theoretical guideline on how to properly design parallel elasticity behaviours for engineering systems such as artificial actuators and robotic joints.

Losartan/hydrochlorothiazide combination vs. high-dose losartan in patients with morning hypertension--a prospective, randomized, open-labeled, parallel-group, multicenter trial.

PubMed

Ueda, Tamenobu; Kai, Hisashi; Imaizumi, Tsutomu

2012-07-01

The treatment of morning hypertension has not been established. We compared the efficacy and safety of a losartan/hydrochlorothiazide (HCTZ) combination and high-dose losartan in patients with morning hypertension. A prospective, randomized, open-labeled, parallel-group, multicenter trial enrolled 216 treated outpatients with morning hypertension evaluated by home blood pressure (BP) self-measurement. Patients were randomly assigned to receive a combination therapy of 50 mg losartan and 12.5 mg HCTZ (n=109) or a high-dose therapy with 100 mg losartan (n=107), each of which were administered once every morning. Primary efficacy end points were morning systolic BP (SBP) level and target BP achievement rate after 3 months of treatment. At baseline, BP levels were similar between the two therapy groups. Morning SBP was reduced from 150.3±10.1 to 131.5±11.5 mm Hg by combination therapy (P<0.001) and from 151.0±9.3 to 142.5±13.6 mm Hg by high-dose therapy (P<0.001). The morning SBP reduction was greater in the combination therapy group than in the high-dose therapy group (P<0.001). Combination therapy decreased evening SBP from 141.6±13.3 to 125.3±13.1 mm Hg (P<0.001), and high-dose therapy decreased evening SBP from 138.9±9.9 to 131.4±13.2 mm Hg (P<0.01). Although both therapies improved target BP achievement rates in the morning and evening (P<0.001 for both), combination therapy increased the achievement rates more than high-dose therapy (P<0.001 and P<0.05, respectively). In clinic measurements, combination therapy was superior to high-dose therapy in reducing SBP and improving the achievement rate (P<0.001 and P<0.01, respectively). Combination therapy decreased urine albumin excretion (P<0.05) whereas high-dose therapy reduced serum uric acid. Both therapies indicated strong adherence and few adverse effects (P<0.001). In conclusion, losartan/HCTZ combination therapy was more effective for controlling morning hypertension and reducing urine albumin than high-dose losartan.

Oral sumatriptan for migraine in children and adolescents: a randomized, multicenter, placebo-controlled, parallel group study.

PubMed

Fujita, Mitsue; Sato, Katsuaki; Nishioka, Hiroshi; Sakai, Fumihiko

2014-04-01

The objective of this article is to evaluate the efficacy and tolerability of two doses of oral sumatriptan vs placebo in the acute treatment of migraine in children and adolescents. Currently, there is no approved prescription medication in Japan for the treatment of migraine in children and adolescents. This was a multicenter, outpatient, single-attack, double-blind, randomized, placebo-controlled, parallel-group study. Eligible patients were children and adolescents aged 10 to 17 years diagnosed with migraine with or without aura (ICHD-II criteria 1.1 or 1.2) from 17 centers. They were randomized to receive sumatriptan 25 mg, 50 mg or placebo (1:1:2). The primary efficacy endpoint was headache relief by two grades on a five-grade scale at two hours post-dose. A total of 178 patients from 17 centers in Japan were enrolled and randomized to an investigational product in double-blind fashion. Of these, 144 patients self-treated a single migraine attack, and all provided a post-dose efficacy assessment and completed the study. The percentage of patients in the full analysis set (FAS) population who report pain relief at two hours post-treatment for the primary endpoint was higher in the placebo group than in the pooled sumatriptan group (38.6% vs 31.1%, 95% CI: -23.02 to 8.04, P  = 0.345). The percentage of patients in the FAS population who reported pain relief at four hours post-dose was higher in the pooled sumatriptan group (63.5%) than in the placebo group (51.4%) but failed to achieve statistical significance ( P  = 0.142). At four hours post-dose, percentages of patients who were pain free or had complete relief of photophobia or phonophobia were numerically higher in the sumatriptan pooled group compared to placebo. Both doses of oral sumatriptan were well tolerated. No adverse events (AEs) were serious or led to study withdrawal. The most common AEs were somnolence in 6% (two patients) in the sumatriptan 25 mg treatment group and chest discomfort in 7% (three patients) in the sumatriptan 50 mg treatment group. There was no statistically significant improvement between the sumatriptan pooled group and the placebo group for pain relief at two hours. Oral sumatriptan was well tolerated.

Test-retest and between-site reliability in a multicenter fMRI study.

PubMed

Friedman, Lee; Stern, Hal; Brown, Gregory G; Mathalon, Daniel H; Turner, Jessica; Glover, Gary H; Gollub, Randy L; Lauriello, John; Lim, Kelvin O; Cannon, Tyrone; Greve, Douglas N; Bockholt, Henry Jeremy; Belger, Aysenil; Mueller, Bryon; Doty, Michael J; He, Jianchun; Wells, William; Smyth, Padhraic; Pieper, Steve; Kim, Seyoung; Kubicki, Marek; Vangel, Mark; Potkin, Steven G

2008-08-01

In the present report, estimates of test-retest and between-site reliability of fMRI assessments were produced in the context of a multicenter fMRI reliability study (FBIRN Phase 1, www.nbirn.net). Five subjects were scanned on 10 MRI scanners on two occasions. The fMRI task was a simple block design sensorimotor task. The impulse response functions to the stimulation block were derived using an FIR-deconvolution analysis with FMRISTAT. Six functionally-derived ROIs covering the visual, auditory and motor cortices, created from a prior analysis, were used. Two dependent variables were compared: percent signal change and contrast-to-noise-ratio. Reliability was assessed with intraclass correlation coefficients derived from a variance components analysis. Test-retest reliability was high, but initially, between-site reliability was low, indicating a strong contribution from site and site-by-subject variance. However, a number of factors that can markedly improve between-site reliability were uncovered, including increasing the size of the ROIs, adjusting for smoothness differences, and inclusion of additional runs. By employing multiple steps, between-site reliability for 3T scanners was increased by 123%. Dropping one site at a time and assessing reliability can be a useful method of assessing the sensitivity of the results to particular sites. These findings should provide guidance toothers on the best practices for future multicenter studies.

Collaborative multicenter trials in Latin America: challenges and opportunities in orthopedic and trauma surgery.

PubMed

Moraes, Vinicius Ynoe de; Belloti, Joao Carlos; Faloppa, Flavio; Bhandari, Mohit

2013-01-01

CONTEXT AND OBJECTIVE Orthopedic research agendas should be considered from a worldwide perspective. Efforts should be planned as the means for obtaining evidence that is valid for health promotion with global outreach. DESIGN AND SETTING Exploratory study conducted at Universidade Federal de São Paulo (Unifesp), São Paulo, Brazil, and McMaster University, Hamilton, Canada. METHODS We identified and analyzed collaborative and multicenter research in Latin America, taking into account American and Canadian efforts as the reference points. We explored aspects of the data available from official sources and used data from traffic accidents as a model for discussing collaborative research in these countries. RESULTS The evaluation showed that the proportion of collaborative and multicenter studies in our setting is small. A brief analysis showed that the death rate due to traffic accidents is very high. Thus, it seems clear to us that initiatives involving collaborative studies are important for defining and better understanding the patterns of injuries resulting from orthopedic trauma and the forms of treatment. Orthopedic research may be an important tool for bringing together orthopedic surgeons, researchers and medical societies for joint action. CONCLUSIONS We have indicated some practical guidelines for initiatives in collaborative research and have proposed some solutions with a summarized plan of action for conducting evidence-based research involving orthopedic trauma.

Addressing data privacy in matched studies via virtual pooling.

PubMed

Saha-Chaudhuri, P; Weinberg, C R

2017-09-07

Data confidentiality and shared use of research data are two desirable but sometimes conflicting goals in research with multi-center studies and distributed data. While ideal for straightforward analysis, confidentiality restrictions forbid creation of a single dataset that includes covariate information of all participants. Current approaches such as aggregate data sharing, distributed regression, meta-analysis and score-based methods can have important limitations. We propose a novel application of an existing epidemiologic tool, specimen pooling, to enable confidentiality-preserving analysis of data arising from a matched case-control, multi-center design. Instead of pooling specimens prior to assay, we apply the methodology to virtually pool (aggregate) covariates within nodes. Such virtual pooling retains most of the information used in an analysis with individual data and since individual participant data is not shared externally, within-node virtual pooling preserves data confidentiality. We show that aggregated covariate levels can be used in a conditional logistic regression model to estimate individual-level odds ratios of interest. The parameter estimates from the standard conditional logistic regression are compared to the estimates based on a conditional logistic regression model with aggregated data. The parameter estimates are shown to be similar to those without pooling and to have comparable standard errors and confidence interval coverage. Virtual data pooling can be used to maintain confidentiality of data from multi-center study and can be particularly useful in research with large-scale distributed data.

Risk Factors for Nursing Home Placement in Alzheimer's Disease: A Longitudinal Study of Cognition, ADL, Service Utilization, and Cholinesterase Inhibitor Treatment

ERIC Educational Resources Information Center

Wattmo, Carina; Wallin, Asa K.; Londos, Elisabet; Minthon, Lennart

2011-01-01

Purpose of the Study: To identify risk factors for early nursing home placement (NHP) in Alzheimer's disease (AD), focusing on the impact of longitudinal change in cognition, activities of daily living (ADL), service utilization, and cholinesterase inhibitor treatment (ChEI). Design and Methods: In an open, 3-year, prospective, multicenter study…

Metering Self-Reported Adherence to Clinical Outcomes in Malaysian Patients with Hypertension: Applying the Stages of Change Model to Healthful Behaviors in the CORFIS Study

ERIC Educational Resources Information Center

Karupaiah, Tilakavati; Wong, Kimberly; Chinna, Karuthan; Arasu, Kanimolli; Chee, Winnie Siew Swee

2015-01-01

The CORFIS ("Community-Based Cardiovascular Risk Factors Intervention Strategies") program was piloted in community clinics in Malaysia to address the lack of health education in chronic disease management. The stages of change model was applied in a multicenter quasi-experimental design to evaluate adherence to advocated behaviors in…

MARBLE: A system for executing expert systems in parallel

NASA Technical Reports Server (NTRS)

Myers, Leonard; Johnson, Coe; Johnson, Dean

1990-01-01

This paper details the MARBLE 2.0 system which provides a parallel environment for cooperating expert systems. The work has been done in conjunction with the development of an intelligent computer-aided design system, ICADS, by the CAD Research Unit of the Design Institute at California Polytechnic State University. MARBLE (Multiple Accessed Rete Blackboard Linked Experts) is a system of C Language Production Systems (CLIPS) expert system tool. A copied blackboard is used for communication between the shells to establish an architecture which supports cooperating expert systems that execute in parallel. The design of MARBLE is simple, but it provides support for a rich variety of configurations, while making it relatively easy to demonstrate the correctness of its parallel execution features. In its most elementary configuration, individual CLIPS expert systems execute on their own processors and communicate with each other through a modified blackboard. Control of the system as a whole, and specifically of writing to the blackboard is provided by one of the CLIPS expert systems, an expert control system.

A Systems Approach to Scalable Transportation Network Modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perumalla, Kalyan S

2006-01-01

Emerging needs in transportation network modeling and simulation are raising new challenges with respect to scal-ability of network size and vehicular traffic intensity, speed of simulation for simulation-based optimization, and fidel-ity of vehicular behavior for accurate capture of event phe-nomena. Parallel execution is warranted to sustain the re-quired detail, size and speed. However, few parallel simulators exist for such applications, partly due to the challenges underlying their development. Moreover, many simulators are based on time-stepped models, which can be computationally inefficient for the purposes of modeling evacuation traffic. Here an approach is presented to de-signing a simulator with memory andmore » speed efficiency as the goals from the outset, and, specifically, scalability via parallel execution. The design makes use of discrete event modeling techniques as well as parallel simulation meth-ods. Our simulator, called SCATTER, is being developed, incorporating such design considerations. Preliminary per-formance results are presented on benchmark road net-works, showing scalability to one million vehicles simu-lated on one processor.« less

CERAMENT treatment of fracture defects (CERTiFy): protocol for a prospective, multicenter, randomized study investigating the use of CERAMENT™ BONE VOID FILLER in tibial plateau fractures

PubMed Central

2014-01-01

Background Bone graft substitutes are widely used for reconstruction of posttraumatic bone defects. However, their clinical significance in comparison to autologous bone grafting, the gold-standard in reconstruction of larger bone defects, still remains under debate. This prospective, randomized, controlled clinical study investigates the differences in pain, quality of life, and cost of care in the treatment of tibia plateau fractures-associated bone defects using either autologous bone grafting or bioresorbable hydroxyapatite/calcium sulphate cement (CERAMENT™|BONE VOID FILLER (CBVF)). Methods/Design CERTiFy (CERament™ Treatment of Fracture defects) is a prospective, multicenter, controlled, randomized trial. We plan to enroll 136 patients with fresh traumatic depression fractures of the proximal tibia (types AO 41-B2 and AO 41-B3) in 13 participating centers in Germany. Patients will be randomized to receive either autologous iliac crest bone graft or CBVF after reduction and osteosynthesis of the fracture to reconstruct the subchondral bone defect and prevent the subsidence of the articular surface. The primary outcome is the SF-12 Physical Component Summary at week 26. The co-primary endpoint is the pain level 26 weeks after surgery measured by a visual analog scale. The SF-12 Mental Component Summary after 26 weeks and costs of care will serve as key secondary endpoints. The study is designed to show non-inferiority of the CBVF treatment to the autologous iliac crest bone graft with respect to the physical component of quality of life. The pain level at 26 weeks after surgery is expected to be lower in the CERAMENT bone void filler treatment group. Discussion CERTiFy is the first randomized multicenter clinical trial designed to compare quality of life, pain, and cost of care in the use of the CBVF and the autologous iliac crest bone graft in the treatment of tibia plateau fractures. The results are expected to influence future treatment recommendations. Trial registration number ClinicalTrials.gov: NCT01828905 PMID:24606670

Multiprocessor graphics computation and display using transputers

NASA Technical Reports Server (NTRS)

Ellis, Graham K.

1988-01-01

A package of two-dimensional graphics routines was developed to run on a transputer-based parallel processing system. These routines were designed to enable applications programmers to easily generate and display results from the transputer network in a graphic format. The graphics procedures were designed for the lowest possible network communication overhead for increased performance. The routines were designed for ease of use and to present an intuitive approach to generating graphics on the transputer parallel processing system.

Transmission Index Research of Parallel Manipulators Based on Matrix Orthogonal Degree

NASA Astrophysics Data System (ADS)

Shao, Zhu-Feng; Mo, Jiao; Tang, Xiao-Qiang; Wang, Li-Ping

2017-11-01

Performance index is the standard of performance evaluation, and is the foundation of both performance analysis and optimal design for the parallel manipulator. Seeking the suitable kinematic indices is always an important and challenging issue for the parallel manipulator. So far, there are extensive studies in this field, but few existing indices can meet all the requirements, such as simple, intuitive, and universal. To solve this problem, the matrix orthogonal degree is adopted, and generalized transmission indices that can evaluate motion/force transmissibility of fully parallel manipulators are proposed. Transmission performance analysis of typical branches, end effectors, and parallel manipulators is given to illustrate proposed indices and analysis methodology. Simulation and analysis results reveal that proposed transmission indices possess significant advantages, such as normalized finite (ranging from 0 to 1), dimensionally homogeneous, frame-free, intuitive and easy to calculate. Besides, proposed indices well indicate the good transmission region and relativity to the singularity with better resolution than the traditional local conditioning index, and provide a novel tool for kinematic analysis and optimal design of fully parallel manipulators.

Work stealing for GPU-accelerated parallel programs in a global address space framework: WORK STEALING ON GPU-ACCELERATED SYSTEMS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arafat, Humayun; Dinan, James; Krishnamoorthy, Sriram

Task parallelism is an attractive approach to automatically load balance the computation in a parallel system and adapt to dynamism exhibited by parallel systems. Exploiting task parallelism through work stealing has been extensively studied in shared and distributed-memory contexts. In this paper, we study the design of a system that uses work stealing for dynamic load balancing of task-parallel programs executed on hybrid distributed-memory CPU-graphics processing unit (GPU) systems in a global-address space framework. We take into account the unique nature of the accelerator model employed by GPUs, the significant performance difference between GPU and CPU execution as a functionmore » of problem size, and the distinct CPU and GPU memory domains. We consider various alternatives in designing a distributed work stealing algorithm for CPU-GPU systems, while taking into account the impact of task distribution and data movement overheads. These strategies are evaluated using microbenchmarks that capture various execution configurations as well as the state-of-the-art CCSD(T) application module from the computational chemistry domain.« less

Work stealing for GPU-accelerated parallel programs in a global address space framework

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arafat, Humayun; Dinan, James; Krishnamoorthy, Sriram

Task parallelism is an attractive approach to automatically load balance the computation in a parallel system and adapt to dynamism exhibited by parallel systems. Exploiting task parallelism through work stealing has been extensively studied in shared and distributed-memory contexts. In this paper, we study the design of a system that uses work stealing for dynamic load balancing of task-parallel programs executed on hybrid distributed-memory CPU-graphics processing unit (GPU) systems in a global-address space framework. We take into account the unique nature of the accelerator model employed by GPUs, the significant performance difference between GPU and CPU execution as a functionmore » of problem size, and the distinct CPU and GPU memory domains. We consider various alternatives in designing a distributed work stealing algorithm for CPU-GPU systems, while taking into account the impact of task distribution and data movement overheads. These strategies are evaluated using microbenchmarks that capture various execution configurations as well as the state-of-the-art CCSD(T) application module from the computational chemistry domain« less

Survival distributions impact the power of randomized placebo-phase design and parallel groups randomized clinical trials.

PubMed

Abrahamyan, Lusine; Li, Chuan Silvia; Beyene, Joseph; Willan, Andrew R; Feldman, Brian M

2011-03-01

The study evaluated the power of the randomized placebo-phase design (RPPD)-a new design of randomized clinical trials (RCTs), compared with the traditional parallel groups design, assuming various response time distributions. In the RPPD, at some point, all subjects receive the experimental therapy, and the exposure to placebo is for only a short fixed period of time. For the study, an object-oriented simulation program was written in R. The power of the simulated trials was evaluated using six scenarios, where the treatment response times followed the exponential, Weibull, or lognormal distributions. The median response time was assumed to be 355 days for the placebo and 42 days for the experimental drug. Based on the simulation results, the sample size requirements to achieve the same level of power were different under different response time to treatment distributions. The scenario where the response times followed the exponential distribution had the highest sample size requirement. In most scenarios, the parallel groups RCT had higher power compared with the RPPD. The sample size requirement varies depending on the underlying hazard distribution. The RPPD requires more subjects to achieve a similar power to the parallel groups design. Copyright © 2011 Elsevier Inc. All rights reserved.

Design considerations and rationale of a multi-center trial to sustain weight loss: the Weight Loss Maintenance Trial.

PubMed

Brantley, Phillip; Appel, Lawrence; Hollis, Jack; Stevens, Victor; Ard, Jamy; Champagne, Catherine; Elmer, Patricia; Harsha, David; Myers, Valerie; Proschan, Michael; William, Vollmer; Svetkey, Laura

2008-01-01

The Weight Loss Maintenance Trial (WLM) is a multi-center, randomized, controlled trial that compares the effects of two 30-month maintenance interventions, i.e., Personal Contact (PC) and Interactive Technology (IT) to a self-directed usual care control group (SD), in overweight or obese individuals who are at high risk for cardiovascular disease. This paper provides an overview of the design and methods, and design considerations and lessons learned from this trial. All participants received a 6-month behavioral weight loss program consisting of weekly group sessions. Participants who lost 4 kg were randomized to one of three conditions (PC, IT, or SD). The PC condition provided monthly contacts with an interventionist primarily via telephone and quarterly face-to-face visits. The IT condition provided frequent, individualized contact through a tailored, website system. Both the PC and IT maintenance programs encouraged the DASH dietary pattern and employed theory-based behavioral techniques to promote maintenance. Design considerations included choice of study population, frequency and type of intervention visits, and choice of primary outcome. Overweight or obese persons with CVD risk factors were studied. The pros and cons of studying this population while excluding others are presented. We studied intervention contact strategies that made fewer demands on participant time and travel, while providing frequent opportunities for interaction. The primary outcome variable for the trial was change in weight from randomization to end of follow-up (30 months). Limits to generalizability are discussed. Individuals in need of weight loss strategies may have been excluded due to barriers associated with internet use. Other participants may have been excluded secondary to a comorbid condition. This paper highlights the design and methods of WLM and informs readers of discussions of critical issues and lessons learned from the trial.

On the impact of communication complexity in the design of parallel numerical algorithms

NASA Technical Reports Server (NTRS)

Gannon, D.; Vanrosendale, J.

1984-01-01

This paper describes two models of the cost of data movement in parallel numerical algorithms. One model is a generalization of an approach due to Hockney, and is suitable for shared memory multiprocessors where each processor has vector capabilities. The other model is applicable to highly parallel nonshared memory MIMD systems. In the second model, algorithm performance is characterized in terms of the communication network design. Techniques used in VLSI complexity theory are also brought in, and algorithm independent upper bounds on system performance are derived for several problems that are important to scientific computation.

On the impact of communication complexity on the design of parallel numerical algorithms

NASA Technical Reports Server (NTRS)

Gannon, D. B.; Van Rosendale, J.

1984-01-01

This paper describes two models of the cost of data movement in parallel numerical alorithms. One model is a generalization of an approach due to Hockney, and is suitable for shared memory multiprocessors where each processor has vector capabilities. The other model is applicable to highly parallel nonshared memory MIMD systems. In this second model, algorithm performance is characterized in terms of the communication network design. Techniques used in VLSI complexity theory are also brought in, and algorithm-independent upper bounds on system performance are derived for several problems that are important to scientific computation.

Design of a MIMD neural network processor

NASA Astrophysics Data System (ADS)

Saeks, Richard E.; Priddy, Kevin L.; Pap, Robert M.; Stowell, S.

1994-03-01

The Accurate Automation Corporation (AAC) neural network processor (NNP) module is a fully programmable multiple instruction multiple data (MIMD) parallel processor optimized for the implementation of neural networks. The AAC NNP design fully exploits the intrinsic sparseness of neural network topologies. Moreover, by using a MIMD parallel processing architecture one can update multiple neurons in parallel with efficiency approaching 100 percent as the size of the network increases. Each AAC NNP module has 8 K neurons and 32 K interconnections and is capable of 140,000,000 connections per second with an eight processor array capable of over one billion connections per second.

Methods for design and evaluation of parallel computating systems (The PISCES project)

NASA Technical Reports Server (NTRS)

Pratt, Terrence W.; Wise, Robert; Haught, Mary JO

1989-01-01

The PISCES project started in 1984 under the sponsorship of the NASA Computational Structural Mechanics (CSM) program. A PISCES 1 programming environment and parallel FORTRAN were implemented in 1984 for the DEC VAX (using UNIX processes to simulate parallel processes). This system was used for experimentation with parallel programs for scientific applications and AI (dynamic scene analysis) applications. PISCES 1 was ported to a network of Apollo workstations by N. Fitzgerald.

Design, implementation, and quality control in the Pathways American-Indian multicenter trial

PubMed Central

Stone, Elaine J.; Norman, James E.; Davis, Sally M.; Stewart, Dawn; Clay, Theresa E.; Caballero, Ben; Lohman, Timothy G.; Murray, David M.

2016-01-01

Background Pathways was the first multicenter American-Indian school-based study to test the effectiveness of an obesity prevention program promoting healthy eating and physical activity. Methods Pathways employed a nested cohort design in which 41 schools were randomized to intervention or control conditions and students within these schools were followed as a cohort (1,704 third graders at baseline). The study’s primary endpoint was percent body fat. Secondary endpoints were levels of fat in school lunches; time spent in physical activity; and knowledge, attitudes, and behaviors regarding diet and exercise. Quality control (QC) included design of data management systems which provided standardization and quality assurance of data collection and processing. Data QC procedures at study centers included manuals of operation, training and certification, and monitoring of performance. Process evaluation was conducted to monitor dose and fidelity of the interventions. Registration and tracking systems were used for students and schools. Results No difference in mean percent body fat at fifth grade was found between the intervention and control schools. Percent of calories from fat and saturated fat in school lunches was significantly reduced in the intervention schools as was total energy intake from 24-hour recalls. Significant increases in self-reported physical activity levels and knowledge of healthy behaviors were found for the intervention school students. Conclusions The Pathways study results provide evidence demonstrating the role schools can play in public health promotion. Its study design and QC systems and procedures provide useful models for other similar school based multi- or single-site studies. PMID:14636805

The Galley Parallel File System

NASA Technical Reports Server (NTRS)

Nieuwejaar, Nils; Kotz, David

1996-01-01

As the I/O needs of parallel scientific applications increase, file systems for multiprocessors are being designed to provide applications with parallel access to multiple disks. Many parallel file systems present applications with a conventional Unix-like interface that allows the application to access multiple disks transparently. The interface conceals the parallelism within the file system, which increases the ease of programmability, but makes it difficult or impossible for sophisticated programmers and libraries to use knowledge about their I/O needs to exploit that parallelism. Furthermore, most current parallel file systems are optimized for a different workload than they are being asked to support. We introduce Galley, a new parallel file system that is intended to efficiently support realistic parallel workloads. We discuss Galley's file structure and application interface, as well as an application that has been implemented using that interface.

Parallel transmission RF pulse design with strict temperature constraints.

PubMed

Deniz, Cem M; Carluccio, Giuseppe; Collins, Christopher

2017-05-01

RF safety in parallel transmission (pTx) is generally ensured by imposing specific absorption rate (SAR) limits during pTx RF pulse design. There is increasing interest in using temperature to ensure safety in MRI. In this work, we present a local temperature correlation matrix formalism and apply it to impose strict constraints on maximum absolute temperature in pTx RF pulse design for head and hip regions. Electromagnetic field simulations were performed on the head and hip of virtual body models. Temperature correlation matrices were calculated for four different exposure durations ranging between 6 and 24 min using simulated fields and body-specific constants. Parallel transmission RF pulses were designed using either SAR or temperature constraints, and compared with each other and unconstrained RF pulse design in terms of excitation fidelity and safety. The use of temperature correlation matrices resulted in better excitation fidelity compared with the use of SAR in parallel transmission RF pulse design (for the 6 min exposure period, 8.8% versus 21.0% for the head and 28.0% versus 32.2% for the hip region). As RF exposure duration increases (from 6 min to 24 min), the benefit of using temperature correlation matrices on RF pulse design diminishes. However, the safety of the subject is always guaranteed (the maximum temperature was equal to 39°C). This trend was observed in both head and hip regions, where the perfusion rates are very different. Copyright © 2017 John Wiley & Sons, Ltd.

77 FR 12598 - Notice Correction; A Multi-Center International Hospital-Based Case-Control Study of Lymphoma in...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-01

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Notice Correction; A Multi-Center International Hospital-Based Case-Control Study of Lymphoma in Asia (AsiaLymph) (NCI) The Federal... project titled, ``A multi-center international hospital-based case-control study of lymphoma in Asia (Asia...

Aerodynamic Shape Optimization of Supersonic Aircraft Configurations via an Adjoint Formulation on Parallel Computers

NASA Technical Reports Server (NTRS)

Reuther, James; Alonso, Juan Jose; Rimlinger, Mark J.; Jameson, Antony

1996-01-01

This work describes the application of a control theory-based aerodynamic shape optimization method to the problem of supersonic aircraft design. The design process is greatly accelerated through the use of both control theory and a parallel implementation on distributed memory computers. Control theory is employed to derive the adjoint differential equations whose solution allows for the evaluation of design gradient information at a fraction of the computational cost required by previous design methods. The resulting problem is then implemented on parallel distributed memory architectures using a domain decomposition approach, an optimized communication schedule, and the MPI (Message Passing Interface) Standard for portability and efficiency. The final result achieves very rapid aerodynamic design based on higher order computational fluid dynamics methods (CFD). In our earlier studies, the serial implementation of this design method was shown to be effective for the optimization of airfoils, wings, wing-bodies, and complex aircraft configurations using both the potential equation and the Euler equations. In our most recent paper, the Euler method was extended to treat complete aircraft configurations via a new multiblock implementation. Furthermore, during the same conference, we also presented preliminary results demonstrating that this basic methodology could be ported to distributed memory parallel computing architectures. In this paper, our concern will be to demonstrate that the combined power of these new technologies can be used routinely in an industrial design environment by applying it to the case study of the design of typical supersonic transport configurations. A particular difficulty of this test case is posed by the propulsion/airframe integration.

[Design and implementation of the ELSA-Brasil biobank: a prospective study in a Brazilian population].

PubMed

Pereira, Alexandre C; Bensenor, Isabela M; Fedeli, Ligia M; Castilhos, Cristina; Vidigal, Pedro G; Maniero, Viviane; Leite, Claudia M; Pimentel, Robercia A; Duncan, Bruce B; Mill, Jose Geraldo; Lotufo, Paulo A

2013-06-01

The Brazilian Longitudinal Study for Adult Health (ELSA-Brasil) is a multicenter prospective cohort of civil servants designed to assess the determinants of chronic diseases, especially cardiovascular diseases and type 2 diabetes. The present article describes the main design and implementation points of the ELSA-Brasil biobank project. Economic, political, logistical and technological aspects of this study are characterized. Additionally, it discusses the final biorepository protocol and the facilities implemented to achieve this objective. The design and implementation process of the ELSA-Brasil biobank took three years to be performed. Both the central and local biobanks were built according to the best biorepository techniques, using different technological solutions for the distinct needs expected in this study.

The engine design engine. A clustered computer platform for the aerodynamic inverse design and analysis of a full engine

NASA Technical Reports Server (NTRS)

Sanz, J.; Pischel, K.; Hubler, D.

1992-01-01

An application for parallel computation on a combined cluster of powerful workstations and supercomputers was developed. A Parallel Virtual Machine (PVM) is used as message passage language on a macro-tasking parallelization of the Aerodynamic Inverse Design and Analysis for a Full Engine computer code. The heterogeneous nature of the cluster is perfectly handled by the controlling host machine. Communication is established via Ethernet with the TCP/IP protocol over an open network. A reasonable overhead is imposed for internode communication, rendering an efficient utilization of the engaged processors. Perhaps one of the most interesting features of the system is its versatile nature, that permits the usage of the computational resources available that are experiencing less use at a given point in time.

Parallel-Vector Algorithm For Rapid Structural Anlysis

NASA Technical Reports Server (NTRS)

Agarwal, Tarun R.; Nguyen, Duc T.; Storaasli, Olaf O.

1993-01-01

New algorithm developed to overcome deficiency of skyline storage scheme by use of variable-band storage scheme. Exploits both parallel and vector capabilities of modern high-performance computers. Gives engineers and designers opportunity to include more design variables and constraints during optimization of structures. Enables use of more refined finite-element meshes to obtain improved understanding of complex behaviors of aerospace structures leading to better, safer designs. Not only attractive for current supercomputers but also for next generation of shared-memory supercomputers.

DCL System Using Deep Learning Approaches for Land-based or Ship-based Real-Time Recognition and Localization of Marine Mammals

DTIC Science & Technology

2012-09-30

platform (HPC) was developed, called the HPC-Acoustic Data Accelerator, or HPC-ADA for short. The HPC-ADA was designed based on fielded systems [1-4...software (Detection cLassificaiton for MAchine learning - High Peformance Computing). The software package was designed to utilize parallel and...Sedna [7] and is designed using a parallel architecture2, allowing existing algorithms to distribute to the various processing nodes with minimal changes

Design of miniature type parallel coupled microstrip hairpin filter in UHF range

NASA Astrophysics Data System (ADS)

Hasan, Adib Belhaj; Rahman, Maj Tarikur; Kahhar, Azizul; Trina, Tasnim; Saha, Pran Kanai

2017-12-01

A microstrip parallel coupled line bandpass filter is designed in UHF range and the filter size is reduced by microstrip hairpin structure. The FR4 substrate is used as base material of the filter. The filter is analyzed by both ADS and CST design studio in the frequency range of 500 MHz to 650 MHz. The Bandwidth is found 13.27% with a center frequency 570 MHz. Simulation from both ADS and CST shows a very good agreement of performance of the filter.

Xyce Parallel Electronic Simulator Users' Guide Version 6.7.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keiter, Eric R.; Aadithya, Karthik Venkatraman; Mei, Ting

This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been designed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: Capability to solve extremely large circuit problems by supporting large-scale parallel com- puting platforms (up to thousands of processors). This includes support for most popular parallel and serial computers. A differential-algebraic-equation (DAE) formulation, which better isolates the device model package from solver algorithms. This allows one tomore » develop new types of analysis without requiring the implementation of analysis-specific device models. Device models that are specifically tailored to meet Sandia's needs, including some radiation- aware devices (for Sandia users only). Object-oriented code design and implementation using modern coding practices. Xyce is a parallel code in the most general sense of the phrase -- a message passing parallel implementation -- which allows it to run efficiently a wide range of computing platforms. These include serial, shared-memory and distributed-memory parallel platforms. Attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved as the number of processors grows. The information herein is subject to change without notice. Copyright c 2002-2017 Sandia Corporation. All rights reserved. Trademarks Xyce TM Electronic Simulator and Xyce TM are trademarks of Sandia Corporation. Orcad, Orcad Capture, PSpice and Probe are registered trademarks of Cadence Design Systems, Inc. Microsoft, Windows and Windows 7 are registered trademarks of Microsoft Corporation. Medici, DaVinci and Taurus are registered trademarks of Synopsys Corporation. Amtec and TecPlot are trademarks of Amtec Engineering, Inc. All other trademarks are property of their respective owners. Contacts World Wide Web http://xyce.sandia.gov https://info.sandia.gov/xyce (Sandia only) Email xyce@sandia.gov (outside Sandia) xyce-sandia@sandia.gov (Sandia only) Bug Reports (Sandia only) http://joseki-vm.sandia.gov/bugzilla http://morannon.sandia.gov/bugzilla« less

Xyce Parallel Electronic Simulator Users' Guide Version 6.8

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keiter, Eric R.; Aadithya, Karthik Venkatraman; Mei, Ting

This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been de- signed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: Capability to solve extremely large circuit problems by supporting large-scale parallel com- puting platforms (up to thousands of processors). This includes support for most popular parallel and serial computers. A differential-algebraic-equation (DAE) formulation, which better isolates the device model package from solver algorithms. This allows onemore » to develop new types of analysis without requiring the implementation of analysis-specific device models. Device models that are specifically tailored to meet Sandia's needs, including some radiation- aware devices (for Sandia users only). Object-oriented code design and implementation using modern coding practices. Xyce is a parallel code in the most general sense of the phrase$-$ a message passing parallel implementation $-$ which allows it to run efficiently a wide range of computing platforms. These include serial, shared-memory and distributed-memory parallel platforms. Attention has been paid to the specific nature of circuit-simulation problems to ensure that optimal parallel efficiency is achieved as the number of processors grows.« less

Multirate parallel distributed compensation of a cluster in wireless sensor and actor networks

NASA Astrophysics Data System (ADS)

Yang, Chun-xi; Huang, Ling-yun; Zhang, Hao; Hua, Wang

2016-01-01

The stabilisation problem for one of the clusters with bounded multiple random time delays and packet dropouts in wireless sensor and actor networks is investigated in this paper. A new multirate switching model is constructed to describe the feature of this single input multiple output linear system. According to the difficulty of controller design under multi-constraints in multirate switching model, this model can be converted to a Takagi-Sugeno fuzzy model. By designing a multirate parallel distributed compensation, a sufficient condition is established to ensure this closed-loop fuzzy control system to be globally exponentially stable. The solution of the multirate parallel distributed compensation gains can be obtained by solving an auxiliary convex optimisation problem. Finally, two numerical examples are given to show, compared with solving switching controller, multirate parallel distributed compensation can be obtained easily. Furthermore, it has stronger robust stability than arbitrary switching controller and single-rate parallel distributed compensation under the same conditions.

Randomized controlled trials and neuro-oncology: should alternative designs be considered?

PubMed

Mansouri, Alireza; Shin, Samuel; Cooper, Benjamin; Srivastava, Archita; Bhandari, Mohit; Kondziolka, Douglas

2015-09-01

Deficiencies in design and reporting of randomized controlled trials (RCTs) hinders interpretability and critical appraisal. The reporting quality of recent RCTs in neuro-oncology was analyzed to assess adequacy of design and reporting. The MEDLINE and EMBASE databases were searched to identify non-surgical RCTs (years 2005-2014, inclusive). The CONSORT and Jadad scales were used to assess the quality of design/reporting. Studies published in 2005-2010 were compared as a cohort against studies published in 2011-2014, in terms of general characteristics and reporting quality. A PRECIS-based scale was used to designate studies on the pragmatic-explanatory continuum. Spearman's test was used to assess correlations. Regression analysis was used to assess associations. Overall 68 RCTs were identified. Studies were often chemotherapy-based (n = 41 studies) focusing upon high grade gliomas (46 %) and metastases (41 %) as the top pathologies. Multi-center trials (71 %) were frequent. The overall median CONSORT and Jadad scores were 34.5 (maximum 44) and 2 (maximum 5), respectively; these scores were similar in radiation and chemotherapy-based trials. Major areas of deficiency pertained to allocation concealment, implementation of methods, and blinding whereby less than 20 % of articles fulfilled all criteria. Description of intervention, random sequence generation, and the details regarding recruitment were also deficient; less than 50 % of studies fulfilled all criteria. Description of sample size calculations and blinding improved in later published cohorts. Journal impact factor was significantly associated with higher quality (p = 0.04). Large academic consortia, multi-center designs, ITT analysis, collaboration with biostatisticians, larger sample sizes, and studies with pragmatic objectives were more likely to achieve positive primary outcomes on univariate analysis; none of these variables were significant on multivariate analysis. Deficiencies in the quality of design/reporting of RCTs in neuro-oncology persist. Quality improvement is necessary. Consideration of alternative strategies should be considered.

A novel visual hardware behavioral language

NASA Technical Reports Server (NTRS)

Li, Xueqin; Cheng, H. D.

1992-01-01

Most hardware behavioral languages just use texts to describe the behavior of the desired hardware design. This is inconvenient for VLSI designers who enjoy using the schematic approach. The proposed visual hardware behavioral language has the ability to graphically express design information using visual parallel models (blocks), visual sequential models (processes) and visual data flow graphs (which consist of primitive operational icons, control icons, and Data and Synchro links). Thus, the proposed visual hardware behavioral language can not only specify hardware concurrent and sequential functionality, but can also visually expose parallelism, sequentiality, and disjointness (mutually exclusive operations) for the hardware designers. That would make the hardware designers capture the design ideas easily and explicitly using this visual hardware behavioral language.

Severe Postpartum Hemorrhage from Uterine Atony: A Multicentric Study

PubMed Central

Montufar-Rueda, Carlos; Rodriguez, Laritza; Jarquin, José Douglas; Barboza, Alejandra; Bustillo, Maura Carolina; Marin, Flor; Ortiz, Guillermo; Estrada, Francisco

2013-01-01

Objective. Postpartum hemorrhage (PPH) is an important cause of maternal mortality (MM) around the world. Seventy percent of the PPH corresponds to uterine atony. The objective of our study was to evaluate multicenter PPH cases during a 10-month period, and evaluate severe postpartum hemorrhage management. Study Design. The study population is a cohort of vaginal delivery and cesarean section patients with severe postpartum hemorrhage secondary to uterine atony. The study was designed as a descriptive, prospective, longitudinal, and multicenter study, during 10 months in 13 teaching hospitals. Results. Total live births during the study period were 124,019 with 218 patients (0.17%) with severe postpartum hemorrhage (SPHH). Total maternal deaths were 8, for mortality rate of 3.6% and a MM rate of 6.45/100,000 live births (LB). Maternal deaths were associated with inadequate transfusion therapy. Conclusions. In all patients with severe hemorrhage and subsequent hypovolemic shock, the most important therapy is intravascular volume resuscitation, to reduce the possibility of target organ damage and death. Similarly, the current proposals of transfusion therapy in severe or massive hemorrhage point to early transfusion of blood products and use of fresh frozen plasma, in addition to packed red blood cells, to prevent maternal deaths. PMID:24363935

[Designing and implementation of a web-based quality monitoring system for plasma glucose measurement in multicenter population study].

PubMed

Liu, Yong; Wang, Limin; Pang, Richard; Mo, Nanxun; Hu, Yan; Deng, Qian; Hu, Zhaohui

2015-05-01

The aim of this paper is to describe the designing and implementation of a web-based plasma glucose measurement quality monitoring system to assess the analytical quality of plasma glucose measurements in multicenter population study and provide evidence for the future studies. In the chronic non-communicable disease and related factor surveillance in China, a web based quality monitoring system for plasma glucose measurement was established to conduct evaluation on plasma glucose monitoring quality and effectiveness in 302 surveillance centers, including quality control data entry, transmission and feedback. The majority of the surveillance centers met the quality requirements and passed the evaluation of reproducibility and precision of plasma glucose measurement, only a few centers required intensive training and re-assessment. In order to ensure the completeness and reliability of plasma glucose measurement in the surveillance centers, the establishment of web-based plasma glucose measurement quality control system can facilitate the identification of the qualified surveillance centers and evaluation of plasma glucose measurement quality in different regions. Communication and training are important in ensuring plasma glucose measurement quality. It is necessary to further improve this web-based plasma glucose measurement quality monitoring system in the future to reduce the method specific plasma glucose measurement bias.

A Review of the Epidemiological Methods Used to Investigate the Health Impacts of Air Pollution around Major Industrial Areas

PubMed Central

Pascal, Laurence; Bidondo, Marie-Laure; Cochet, Amandine; Sarter, Hélène; Stempfelet, Morgane; Wagner, Vérène

2013-01-01

We performed a literature review to investigate how epidemiological studies have been used to assess the health consequences of living in the vicinity of industries. 77 papers on the chronic effects of air pollution around major industrial areas were reviewed. Major health themes were cancers (27 studies), morbidity (25 studies), mortality (7 studies), and birth outcome (7 studies). Only 3 studies investigated mental health. While studies were available from many different countries, a majority of papers came from the United Kingdom, Italy, and Spain. Several studies were motivated by concerns from the population or by previous observations of an overincidence of cases. Geographical ecological designs were largely used for studying cancer and mortality, including statistical designs to quantify a relationship between health indicators and exposure. Morbidity was frequently investigated through cross-sectional surveys on the respiratory health of children. Few multicenter studies were performed. In a majority of papers, exposed areas were defined based on the distance to the industry and were located from <2 km to >20 km from the plants. Improving the exposure assessment would be an asset to future studies. Criteria to include industries in multicenter studies should be defined. PMID:23818910

A manual-based individual therapy to improve metacognition in schizophrenia: protocol of a multi-center RCT

PubMed Central

2014-01-01

Background Metacognitive dysfunction has been widely recognized as a feature of schizophrenia. As it is linked with deficits in several aspects of daily life functioning, improvement of metacognition may lead to improvement in functioning. Individual psychotherapy might be a useful form of treatment to improve metacognition in patients with schizophrenia; multiple case reports and a pilot study show promising results. The present study aims to measure the effectiveness of an individual, manual-based therapy (Metacognitive Reflection and Insight Therapy, MERIT) in improving metacognition in patients with schizophrenia. We also want to examine if improvement in metacognitive abilities is correlated with improvements in aspects of daily life functioning namely social functioning, experience of symptoms, quality of life, depression, work readiness, insight and experience of stigma. Methods/Design MERIT is currently evaluated in a multicenter randomized controlled trial. Thirteen therapists in six mental health institutions in the Netherlands participate in this study. Patients are randomly assigned to either MERIT or the control condition: treatment as usual (TAU). Discussion If proven effective, MERIT can be a useful addition to the care for schizophrenia patients. The design brings along some methodological difficulties, these issues are addressed in the discussion of this paper. Trial registration Current Controlled Trials: ISRCTN16659871. PMID:24490942

EWOLUTION: Design of a registry to evaluate real-world clinical outcomes in patients with AF and high stroke risk-treated with the WATCHMAN left atrial appendage closure technology.

PubMed

Boersma, Lucas V A; Schmidt, Boris; Betts, Tim R; Sievert, Horst; Tamburino, Corrado; Teiger, Emmanuel; Stein, Kenneth M; Bergmann, Martin W

2016-09-01

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and the rate of ischemic stroke attributed to non-valvular AF is estimated at 5% per year. Several multi-center studies established left atrial appendage closure as a safe and effective alternative to oral anticoagulation, but there is a need for additional real world data. The purpose of this observational, prospective, single-arm, multicenter clinical study is to compile real-world clinical outcome data for WATCHMAN™ LAA (left atrial appendage) Closure Technology. One thousand subjects at up to 70 institutions in Europe, the Middle East, and Russia will be enrolled. Patients will be followed for 2 years after WATCHMAN implantation, according to standard medical practice. Primary endpoints include procedural and long-term data including stroke/embolism, bleeding, and death. This article presents the background of the LAAC device and describes the design of the study. Results for peri-procedural analyses are expected toward the end of 2015; long-term follow-up data are expected in the latter half of 2017. The EWOLUTION study will formally expand knowledge of LAA closure into a broader real world setting. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Conducting multicenter research in healthcare simulation: Lessons learned from the INSPIRE network.

PubMed

Cheng, Adam; Kessler, David; Mackinnon, Ralph; Chang, Todd P; Nadkarni, Vinay M; Hunt, Elizabeth A; Duval-Arnould, Jordan; Lin, Yiqun; Pusic, Martin; Auerbach, Marc

2017-01-01

Simulation-based research has grown substantially over the past two decades; however, relatively few published simulation studies are multicenter in nature. Multicenter research confers many distinct advantages over single-center studies, including larger sample sizes for more generalizable findings, sharing resources amongst collaborative sites, and promoting networking. Well-executed multicenter studies are more likely to improve provider performance and/or have a positive impact on patient outcomes. In this manuscript, we offer a step-by-step guide to conducting multicenter, simulation-based research based upon our collective experience with the International Network for Simulation-based Pediatric Innovation, Research and Education (INSPIRE). Like multicenter clinical research, simulation-based multicenter research can be divided into four distinct phases. Each phase has specific differences when applied to simulation research: (1) Planning phase , to define the research question, systematically review the literature, identify outcome measures, and conduct pilot studies to ensure feasibility and estimate power; (2) Project Development phase , when the primary investigator identifies collaborators, develops the protocol and research operations manual, prepares grant applications, obtains ethical approval and executes subsite contracts, registers the study in a clinical trial registry, forms a manuscript oversight committee, and conducts feasibility testing and data validation at each site; (3) Study Execution phase , involving recruitment and enrollment of subjects, clear communication and decision-making, quality assurance measures and data abstraction, validation, and analysis; and (4) Dissemination phase , where the research team shares results via conference presentations, publications, traditional media, social media, and implements strategies for translating results to practice. With this manuscript, we provide a guide to conducting quantitative multicenter research with a focus on simulation-specific issues.

Accelerating large-scale protein structure alignments with graphics processing units

PubMed Central

2012-01-01

Background Large-scale protein structure alignment, an indispensable tool to structural bioinformatics, poses a tremendous challenge on computational resources. To ensure structure alignment accuracy and efficiency, efforts have been made to parallelize traditional alignment algorithms in grid environments. However, these solutions are costly and of limited accessibility. Others trade alignment quality for speedup by using high-level characteristics of structure fragments for structure comparisons. Findings We present ppsAlign, a parallel protein structure Alignment framework designed and optimized to exploit the parallelism of Graphics Processing Units (GPUs). As a general-purpose GPU platform, ppsAlign could take many concurrent methods, such as TM-align and Fr-TM-align, into the parallelized algorithm design. We evaluated ppsAlign on an NVIDIA Tesla C2050 GPU card, and compared it with existing software solutions running on an AMD dual-core CPU. We observed a 36-fold speedup over TM-align, a 65-fold speedup over Fr-TM-align, and a 40-fold speedup over MAMMOTH. Conclusions ppsAlign is a high-performance protein structure alignment tool designed to tackle the computational complexity issues from protein structural data. The solution presented in this paper allows large-scale structure comparisons to be performed using massive parallel computing power of GPU. PMID:22357132

Programming Probabilistic Structural Analysis for Parallel Processing Computer

NASA Technical Reports Server (NTRS)

Sues, Robert H.; Chen, Heh-Chyun; Twisdale, Lawrence A.; Chamis, Christos C.; Murthy, Pappu L. N.

1991-01-01

The ultimate goal of this research program is to make Probabilistic Structural Analysis (PSA) computationally efficient and hence practical for the design environment by achieving large scale parallelism. The paper identifies the multiple levels of parallelism in PSA, identifies methodologies for exploiting this parallelism, describes the development of a parallel stochastic finite element code, and presents results of two example applications. It is demonstrated that speeds within five percent of those theoretically possible can be achieved. A special-purpose numerical technique, the stochastic preconditioned conjugate gradient method, is also presented and demonstrated to be extremely efficient for certain classes of PSA problems.

Design and analysis of all-dielectric broadband nonpolarizing parallel-plate beam splitters.

PubMed

Wang, Wenliang; Xiong, Shengming; Zhang, Yundong

2007-06-01

Past research on the all-dielectric nonpolarizing beam splitter is reviewed. With the aid of the needle thin-film synthesis method and the conjugate graduate refine method, three different split ratio nonpolarizing parallel-plate beam splitters over a 200 nm spectral range centered at 550 nm with incidence angles of 45 degrees are designed. The chosen materials component and the initial stack are based on the Costich and Thelen theories. The results of design and analysis show that the designs maintain a very low polarization ratio in the working range of the spectrum and has a reasonable angular field.

Evaluation of fault-tolerant parallel-processor architectures over long space missions

NASA Technical Reports Server (NTRS)

Johnson, Sally C.

1989-01-01

The impact of a five year space mission environment on fault-tolerant parallel processor architectures is examined. The target application is a Strategic Defense Initiative (SDI) satellite requiring 256 parallel processors to provide the computation throughput. The reliability requirements are that the system still be operational after five years with .99 probability and that the probability of system failure during one-half hour of full operation be less than 10(-7). The fault tolerance features an architecture must possess to meet these reliability requirements are presented, many potential architectures are briefly evaluated, and one candidate architecture, the Charles Stark Draper Laboratory's Fault-Tolerant Parallel Processor (FTPP) is evaluated in detail. A methodology for designing a preliminary system configuration to meet the reliability and performance requirements of the mission is then presented and demonstrated by designing an FTPP configuration.

Multicenter Automatic Defibrillator Implantation Trial-Subcutaneous Implantable Cardioverter Defibrillator (MADIT S-ICD): Design and clinical protocol.

PubMed

Kutyifa, Valentina; Beck, Christopher; Brown, Mary W; Cannom, David; Daubert, James; Estes, Mark; Greenberg, Henry; Goldenberg, Ilan; Hammes, Stephen; Huang, David; Klein, Helmut; Knops, Reinoud; Kosiborod, Mikhail; Poole, Jeanne; Schuger, Claudio; Singh, Jagmeet P; Solomon, Scott; Wilber, David; Zareba, Wojciech; Moss, Arthur J

2017-07-01

Patients with diabetes mellitus, prior myocardial infarction, older age, and a relatively preserved left ventricular ejection fraction remain at risk for sudden cardiac death that is potentially amenable by the subcutaneous implantable cardioverter defibrillator with a good risk-benefit profile. The launched MADIT S-ICD study is designed to test the hypothesis that post-myocardial infarction diabetes patients with relatively preserved ejection fraction of 36%-50% will have a survival benefit from a subcutaneous implantable cardioverter defibrillator. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

A Next-Generation Parallel File System Environment for the OLCF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dillow, David A; Fuller, Douglas; Gunasekaran, Raghul

2012-01-01

When deployed in 2008/2009 the Spider system at the Oak Ridge National Laboratory s Leadership Computing Facility (OLCF) was the world s largest scale Lustre parallel file system. Envisioned as a shared parallel file system capable of delivering both the bandwidth and capacity requirements of the OLCF s diverse computational environment, Spider has since become a blueprint for shared Lustre environments deployed worldwide. Designed to support the parallel I/O requirements of the Jaguar XT5 system and other smallerscale platforms at the OLCF, the upgrade to the Titan XK6 heterogeneous system will begin to push the limits of Spider s originalmore » design by mid 2013. With a doubling in total system memory and a 10x increase in FLOPS, Titan will require both higher bandwidth and larger total capacity. Our goal is to provide a 4x increase in total I/O bandwidth from over 240GB=sec today to 1TB=sec and a doubling in total capacity. While aggregate bandwidth and total capacity remain important capabilities, an equally important goal in our efforts is dramatically increasing metadata performance, currently the Achilles heel of parallel file systems at leadership. We present in this paper an analysis of our current I/O workloads, our operational experiences with the Spider parallel file systems, the high-level design of our Spider upgrade, and our efforts in developing benchmarks that synthesize our performance requirements based on our workload characterization studies.« less

Estimating relative risks in multicenter studies with a small number of centers - which methods to use? A simulation study.

PubMed

Pedroza, Claudia; Truong, Van Thi Thanh

2017-11-02

Analyses of multicenter studies often need to account for center clustering to ensure valid inference. For binary outcomes, it is particularly challenging to properly adjust for center when the number of centers or total sample size is small, or when there are few events per center. Our objective was to evaluate the performance of generalized estimating equation (GEE) log-binomial and Poisson models, generalized linear mixed models (GLMMs) assuming binomial and Poisson distributions, and a Bayesian binomial GLMM to account for center effect in these scenarios. We conducted a simulation study with few centers (≤30) and 50 or fewer subjects per center, using both a randomized controlled trial and an observational study design to estimate relative risk. We compared the GEE and GLMM models with a log-binomial model without adjustment for clustering in terms of bias, root mean square error (RMSE), and coverage. For the Bayesian GLMM, we used informative neutral priors that are skeptical of large treatment effects that are almost never observed in studies of medical interventions. All frequentist methods exhibited little bias, and the RMSE was very similar across the models. The binomial GLMM had poor convergence rates, ranging from 27% to 85%, but performed well otherwise. The results show that both GEE models need to use small sample corrections for robust SEs to achieve proper coverage of 95% CIs. The Bayesian GLMM had similar convergence rates but resulted in slightly more biased estimates for the smallest sample sizes. However, it had the smallest RMSE and good coverage across all scenarios. These results were very similar for both study designs. For the analyses of multicenter studies with a binary outcome and few centers, we recommend adjustment for center with either a GEE log-binomial or Poisson model with appropriate small sample corrections or a Bayesian binomial GLMM with informative priors.

Sensitivity subgroup analysis based on single-center vs. multi-center trial status when interpreting meta-analyses pooled estimates: the logical way forward.

PubMed

Alexander, Paul E; Bonner, Ashley J; Agarwal, Arnav; Li, Shelly-Anne; Hariharan, Abishek; Izhar, Zain; Bhatnagar, Neera; Alba, Carolina; Akl, Elie A; Fei, Yutong; Guyatt, Gordon H; Beyene, Joseph

2016-06-01

Prior studies regarding whether single-center trial estimates are larger than multi-center are equivocal. We examined the extent to which single-center trials yield systematically larger effects than multi-center trials. We searched the 119 core clinical journals and the Cochrane Database of Systematic Reviews for meta-analyses (MAs) of randomized controlled trials (RCTs) published during 2012. In this meta-epidemiologic study, for binary variables, we computed the pooled ratio of ORs (RORs), and for continuous outcomes mean difference in standardized mean differences (SMDs), we conducted weighted random-effects meta-regression and random-effects MA modeling. Our primary analyses were restricted to MAs that included at least five RCTs and in which at least 25% of the studies used each of single trial center (SC) and more trial center (MC) designs. We identified 81 MAs for the odds ratio (OR) and 43 for the SMD outcome measures. Based on our analytic plan, our primary analysis (core) is based on 25 MAs/241 RCTs (binary outcome) and 18 MAs/173 RCTs (continuous outcome). Based on the core analysis, we found no difference in magnitude of effect between SC and MC for binary outcomes [RORs: 1.02; 95% confidence interval (CI): 0.83, 1.24; I(2) 20.2%]. Effect sizes were systematically larger for SC than MC for the continuous outcome measure (mean difference in SMDs: -0.13; 95% CI: -0.21, -0.05; I(2) 0%). Our results do not support prior findings of larger effects in SC than MC trials addressing binary outcomes but show a very similar small increase in effect in SC than MC trials addressing continuous outcomes. Authors of systematic reviews would be wise to include all trials irrespective of SC vs. MC design and address SC vs. MC status as a possible explanation of heterogeneity (and consider sensitivity analyses). Copyright © 2015 Elsevier Inc. All rights reserved.

A Multicenter Radiographic Evaluation of the Rates of Preoperative and Postoperative Malalignment in Degenerative Spinal Fusions.

PubMed

Leveque, Jean-Christophe A; Segebarth, Bradley; Schroerlucke, Samuel R; Khanna, Nitin; Pollina, John; Youssef, Jim A; Tohmeh, Antoine G; Uribe, Juan S

2018-07-01

Multicenter, retrospective, institutional-review-board -approved study at 18 institutions in the United States with 24 treating investigators. This study was designed to retrospectively assess the prevalence of spinopelvic malalignment in patients who underwent one- or two-level lumbar fusions for degenerative (nondeformity) indications and to assess the incidence of malalignment after fusion surgery as well as the rate of alignment preservation and/or correction in this population. Spinopelvic malalignment after lumbar fusion has been associated with lower postoperative health-related quality of life and elevated risk of adjacent segment failure. The prevalence of spinopelvic malalignment in short-segment degenerative lumbar fusion procedures from a large sample of patients is heretofore unreported and may lead to an under-appreciation of these factors in surgical planning and ultimate preservation or correction of alignment. Lateral preoperative and postoperative lumbar radiographs were retrospectively acquired from 578 one- or two-level lumbar fusion patients and newly measured for lumbar lordosis (LL), pelvic incidence (PI), and pelvic tilt. Patients were categorized at preop and postop time points as aligned if PI-LL < 10° or malaligned if PI-LL≥10°. Patients were grouped into categories based on their alignment progression from pre- to postoperative, with preserved (aligned to aligned), restored (malaligned to aligned), not corrected (malaligned to malaligned), and worsened (aligned to malaligned) designations. Preoperatively, 173 (30%) patients exhibited malalignment. Postoperatively, 161 (28%) of patients were malaligned. Alignment was preserved in 63%, restored in 9%, not corrected in 21%, and worsened in 7% of patients. This is the first multicenter study to evaluate the preoperative prevalence and postoperative incidence of spinopelvic malalignment in a large series of short-segment degenerative lumbar fusions, finding over 25% of patients out of alignment at both time points, suggesting that alignment preservation/restoration considerations should be incorporated into the decision-making of even degenerative lumbar spinal fusions. 3.

Testing the methodology for dosimetry audit of heterogeneity corrections and small MLC-shaped fields: Results of IAEA multi-center studies

PubMed Central

Izewska, Joanna; Wesolowska, Paulina; Azangwe, Godfrey; Followill, David S.; Thwaites, David I.; Arib, Mehenna; Stefanic, Amalia; Viegas, Claudio; Suming, Luo; Ekendahl, Daniela; Bulski, Wojciech; Georg, Dietmar

2016-01-01

Abstract The International Atomic Energy Agency (IAEA) has a long tradition of supporting development of methodologies for national networks providing quality audits in radiotherapy. A series of co-ordinated research projects (CRPs) has been conducted by the IAEA since 1995 assisting national external audit groups developing national audit programs. The CRP ‘Development of Quality Audits for Radiotherapy Dosimetry for Complex Treatment Techniques’ was conducted in 2009–2012 as an extension of previously developed audit programs. Material and methods. The CRP work described in this paper focused on developing and testing two steps of dosimetry audit: verification of heterogeneity corrections, and treatment planning system (TPS) modeling of small MLC fields, which are important for the initial stages of complex radiation treatments, such as IMRT. The project involved development of a new solid slab phantom with heterogeneities containing special measurement inserts for thermoluminescent dosimeters (TLD) and radiochromic films. The phantom and the audit methodology has been developed at the IAEA and tested in multi-center studies involving the CRP participants. Results. The results of multi-center testing of methodology for two steps of dosimetry audit show that the design of audit procedures is adequate and the methodology is feasible for meeting the audit objectives. A total of 97% TLD results in heterogeneity situations obtained in the study were within 3% and all results within 5% agreement with the TPS predicted doses. In contrast, only 64% small beam profiles were within 3 mm agreement between the TPS calculated and film measured doses. Film dosimetry results have highlighted some limitations in TPS modeling of small beam profiles in the direction of MLC leave movements. Discussion. Through multi-center testing, any challenges or difficulties in the proposed audit methodology were identified, and the methodology improved. Using the experience of these studies, the participants could incorporate the auditing procedures in their national programs. PMID:26934916

Diagnostic performance of computed tomography coronary angiography (from the Prospective National Multicenter Multivendor EVASCAN Study).

PubMed

Gueret, Pascal; Deux, Jean-François; Bonello, Laurent; Sarran, Anthony; Tron, Christophe; Christiaens, Luc; Dacher, Jean-Nicolas; Bertrand, David; Leborgne, Laurent; Renard, Cedric; Caussin, Christophe; Cluzel, Philippe; Helft, Gerard; Crochet, Dominique; Vernhet-Kovacsik, Hélène; Chabbert, Valérie; Ferrari, Emile; Gilard, Martine; Willoteaux, Serge; Furber, Alain; Barone-Rochette, Gilles; Jankowski, Adrien; Douek, Philippe; Mousseaux, Elie; Sirol, Marc; Niarra, Ralph; Chatellier, Gilles; Laissy, Jean-Pierre

2013-02-15

Computed tomographic coronary angiography (CTCA) has been proposed as a noninvasive test for significant coronary artery disease (CAD), but only limited data are available from prospective multicenter trials. The goal of this study was to establish the diagnostic accuracy of CTCA compared to coronary angiography (CA) in a large population of symptomatic patients with clinical indications for coronary imaging. This national, multicenter study was designed to prospectively evaluate stable patients able to undergo CTCA followed by conventional CA. Data from CTCA and CA were analyzed in a blinded fashion at central core laboratories. The main outcome was the evaluation of patient-, vessel-, and segment-based diagnostic performance of CTCA to detect or rule out significant CAD (≥50% luminal diameter reduction). Of 757 patients enrolled, 746 (mean age 61 ± 12 years, 71% men) were analyzed. They underwent CTCA followed by CA 1.7 ± 0.8 days later using a 64-detector scanner. The prevalence of significant CAD in native coronary vessels by CA was 54%. The rate of nonassessable segments by CTCA was 6%. In a patient-based analysis, sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios of CTCA were 91%, 50%, 68%, 83%, 1.82, and 0.18, respectively. The strongest predictors of false-negative results on CTCA were high estimated pretest probability of CAD (odds ratio [OR] 1.97, p <0.001), male gender (OR 1.5, p <0.002), diabetes (OR 1.5, p <0.0001), and age (OR 1.2, p <0.0001). In conclusion, in this large multicenter study, CTCA identified significant CAD with high sensitivity. However, in routine clinical practice, each patient should be individually evaluated, and the pretest probability of obstructive CAD should be taken into account when deciding which method, CTCA or CA, to use to diagnose its presence and severity. Copyright © 2013 Elsevier Inc. All rights reserved.

Testing the methodology for dosimetry audit of heterogeneity corrections and small MLC-shaped fields: Results of IAEA multi-center studies.

PubMed

Izewska, Joanna; Wesolowska, Paulina; Azangwe, Godfrey; Followill, David S; Thwaites, David I; Arib, Mehenna; Stefanic, Amalia; Viegas, Claudio; Suming, Luo; Ekendahl, Daniela; Bulski, Wojciech; Georg, Dietmar

2016-07-01

The International Atomic Energy Agency (IAEA) has a long tradition of supporting development of methodologies for national networks providing quality audits in radiotherapy. A series of co-ordinated research projects (CRPs) has been conducted by the IAEA since 1995 assisting national external audit groups developing national audit programs. The CRP 'Development of Quality Audits for Radiotherapy Dosimetry for Complex Treatment Techniques' was conducted in 2009-2012 as an extension of previously developed audit programs. The CRP work described in this paper focused on developing and testing two steps of dosimetry audit: verification of heterogeneity corrections, and treatment planning system (TPS) modeling of small MLC fields, which are important for the initial stages of complex radiation treatments, such as IMRT. The project involved development of a new solid slab phantom with heterogeneities containing special measurement inserts for thermoluminescent dosimeters (TLD) and radiochromic films. The phantom and the audit methodology has been developed at the IAEA and tested in multi-center studies involving the CRP participants. The results of multi-center testing of methodology for two steps of dosimetry audit show that the design of audit procedures is adequate and the methodology is feasible for meeting the audit objectives. A total of 97% TLD results in heterogeneity situations obtained in the study were within 3% and all results within 5% agreement with the TPS predicted doses. In contrast, only 64% small beam profiles were within 3 mm agreement between the TPS calculated and film measured doses. Film dosimetry results have highlighted some limitations in TPS modeling of small beam profiles in the direction of MLC leave movements. Through multi-center testing, any challenges or difficulties in the proposed audit methodology were identified, and the methodology improved. Using the experience of these studies, the participants could incorporate the auditing procedures in their national programs.

Compact hohlraum configuration with parallel planar-wire-array x-ray sources at the 1.7-MA Zebra generator.

PubMed

Kantsyrev, V L; Chuvatin, A S; Rudakov, L I; Velikovich, A L; Shrestha, I K; Esaulov, A A; Safronova, A S; Shlyaptseva, V V; Osborne, G C; Astanovitsky, A L; Weller, M E; Stafford, A; Schultz, K A; Cooper, M C; Cuneo, M E; Jones, B; Vesey, R A

2014-12-01

A compact Z-pinch x-ray hohlraum design with parallel-driven x-ray sources is experimentally demonstrated in a configuration with a central target and tailored shine shields at a 1.7-MA Zebra generator. Driving in parallel two magnetically decoupled compact double-planar-wire Z pinches has demonstrated the generation of synchronized x-ray bursts that correlated well in time with x-ray emission from a central reemission target. Good agreement between simulated and measured hohlraum radiation temperature of the central target is shown. The advantages of compact hohlraum design applications for multi-MA facilities are discussed.

Parallel/distributed direct method for solving linear systems

NASA Technical Reports Server (NTRS)

Lin, Avi

1990-01-01

A new family of parallel schemes for directly solving linear systems is presented and analyzed. It is shown that these schemes exhibit a near optimal performance and enjoy several important features: (1) For large enough linear systems, the design of the appropriate paralleled algorithm is insensitive to the number of processors as its performance grows monotonically with them; (2) It is especially good for large matrices, with dimensions large relative to the number of processors in the system; (3) It can be used in both distributed parallel computing environments and tightly coupled parallel computing systems; and (4) This set of algorithms can be mapped onto any parallel architecture without any major programming difficulties or algorithmical changes.

Design and implementation of highly parallel pipelined VLSI systems

NASA Astrophysics Data System (ADS)

Delange, Alphonsus Anthonius Jozef

A methodology and its realization as a prototype CAD (Computer Aided Design) system for the design and analysis of complex multiprocessor systems is presented. The design is an iterative process in which the behavioral specifications of the system components are refined into structural descriptions consisting of interconnections and lower level components etc. A model for the representation and analysis of multiprocessor systems at several levels of abstraction and an implementation of a CAD system based on this model are described. A high level design language, an object oriented development kit for tool design, a design data management system, and design and analysis tools such as a high level simulator and graphics design interface which are integrated into the prototype system and graphics interface are described. Procedures for the synthesis of semiregular processor arrays, and to compute the switching of input/output signals, memory management and control of processor array, and sequencing and segmentation of input/output data streams due to partitioning and clustering of the processor array during the subsequent synthesis steps, are described. The architecture and control of a parallel system is designed and each component mapped to a module or module generator in a symbolic layout library, compacted for design rules of VLSI (Very Large Scale Integration) technology. An example of the design of a processor that is a useful building block for highly parallel pipelined systems in the signal/image processing domains is given.

NAS Requirements Checklist for Job Queuing/Scheduling Software

NASA Technical Reports Server (NTRS)

Jones, James Patton

1996-01-01

The increasing reliability of parallel systems and clusters of computers has resulted in these systems becoming more attractive for true production workloads. Today, the primary obstacle to production use of clusters of computers is the lack of a functional and robust Job Management System for parallel applications. This document provides a checklist of NAS requirements for job queuing and scheduling in order to make most efficient use of parallel systems and clusters for parallel applications. Future requirements are also identified to assist software vendors with design planning.

TECA: A Parallel Toolkit for Extreme Climate Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prabhat, Mr; Ruebel, Oliver; Byna, Surendra

2012-03-12

We present TECA, a parallel toolkit for detecting extreme events in large climate datasets. Modern climate datasets expose parallelism across a number of dimensions: spatial locations, timesteps and ensemble members. We design TECA to exploit these modes of parallelism and demonstrate a prototype implementation for detecting and tracking three classes of extreme events: tropical cyclones, extra-tropical cyclones and atmospheric rivers. We process a modern TB-sized CAM5 simulation dataset with TECA, and demonstrate good runtime performance for the three case studies.

Parallel Calculation of Sensitivity Derivatives for Aircraft Design using Automatic Differentiation

NASA Technical Reports Server (NTRS)

Bischof, c. H.; Green, L. L.; Haigler, K. J.; Knauff, T. L., Jr.

1994-01-01

Sensitivity derivative (SD) calculation via automatic differentiation (AD) typical of that required for the aerodynamic design of a transport-type aircraft is considered. Two ways of computing SD via code generated by the ADIFOR automatic differentiation tool are compared for efficiency and applicability to problems involving large numbers of design variables. A vector implementation on a Cray Y-MP computer is compared with a coarse-grained parallel implementation on an IBM SP1 computer, employing a Fortran M wrapper. The SD are computed for a swept transport wing in turbulent, transonic flow; the number of geometric design variables varies from 1 to 60 with coupling between a wing grid generation program and a state-of-the-art, 3-D computational fluid dynamics program, both augmented for derivative computation via AD. For a small number of design variables, the Cray Y-MP implementation is much faster. As the number of design variables grows, however, the IBM SP1 becomes an attractive alternative in terms of compute speed, job turnaround time, and total memory available for solutions with large numbers of design variables. The coarse-grained parallel implementation also can be moved easily to a network of workstations.

Adaptive multi-GPU Exchange Monte Carlo for the 3D Random Field Ising Model

NASA Astrophysics Data System (ADS)

Navarro, Cristóbal A.; Huang, Wei; Deng, Youjin

2016-08-01

This work presents an adaptive multi-GPU Exchange Monte Carlo approach for the simulation of the 3D Random Field Ising Model (RFIM). The design is based on a two-level parallelization. The first level, spin-level parallelism, maps the parallel computation as optimal 3D thread-blocks that simulate blocks of spins in shared memory with minimal halo surface, assuming a constant block volume. The second level, replica-level parallelism, uses multi-GPU computation to handle the simulation of an ensemble of replicas. CUDA's concurrent kernel execution feature is used in order to fill the occupancy of each GPU with many replicas, providing a performance boost that is more notorious at the smallest values of L. In addition to the two-level parallel design, the work proposes an adaptive multi-GPU approach that dynamically builds a proper temperature set free of exchange bottlenecks. The strategy is based on mid-point insertions at the temperature gaps where the exchange rate is most compromised. The extra work generated by the insertions is balanced across the GPUs independently of where the mid-point insertions were performed. Performance results show that spin-level performance is approximately two orders of magnitude faster than a single-core CPU version and one order of magnitude faster than a parallel multi-core CPU version running on 16-cores. Multi-GPU performance is highly convenient under a weak scaling setting, reaching up to 99 % efficiency as long as the number of GPUs and L increase together. The combination of the adaptive approach with the parallel multi-GPU design has extended our possibilities of simulation to sizes of L = 32 , 64 for a workstation with two GPUs. Sizes beyond L = 64 can eventually be studied using larger multi-GPU systems.

Effect of berberine on insulin resistance in women with polycystic ovary syndrome: study protocol for a randomized multicenter controlled trial.

PubMed

Li, Yan; Ma, Hongli; Zhang, Yuehui; Kuang, Hongying; Ng, Ernest Hung Yu; Hou, Lihui; Wu, Xiaoke

2013-07-18

Insulin resistance and hyperinsulinemia play a key role in the pathogenesis of polycystic ovary syndrome (PCOS), which is characterized by hyperandrogenism, ovulatory dysfunction, and presence of polycystic ovaries on pelvic scanning. Insulin resistance is significantly associated with the long-term risks of metabolic syndrome and cardiovascular disease. Berberine has effects on insulin resistance but its use in women with PCOS has not been fully investigated. In this paper, we present a research design evaluating the effects of berberine on insulin resistance in women with PCOS. This is a multicenter, randomized, placebo-controlled and double-blind trial. A total of 120 patients will be enrolled in this study and will be randomized into two groups. Berberine or placebo will be taken orally for 12 weeks. The primary outcome is the whole body insulin action assessed with the hyperinsulinemic-euglycemic clamp. We postulate that women with PCOS will have improved insulin resistance following berberine administration. This study is registered at ClinicalTrials.gov, NCT01138930.

A computer-assisted data collection system for use in a multicenter study of American Indians and Alaska Natives: SCAPES.

PubMed

Edwards, Roger L; Edwards, Sandra L; Bryner, James; Cunningham, Kelly; Rogers, Amy; Slattery, Martha L

2008-04-01

We describe a computer-assisted data collection system developed for a multicenter cohort study of American Indian and Alaska Native people. The study computer-assisted participant evaluation system or SCAPES is built around a central database server that controls a small private network with touch screen workstations. SCAPES encompasses the self-administered questionnaires, the keyboard-based stations for interviewer-administered questionnaires, a system for inputting medical measurements, and administrative tasks such as data exporting, backup and management. Elements of SCAPES hardware/network design, data storage, programming language, software choices, questionnaire programming including the programming of questionnaires administered using audio computer-assisted self-interviewing (ACASI), and participant identification/data security system are presented. Unique features of SCAPES are that data are promptly made available to participants in the form of health feedback; data can be quickly summarized for tribes for health monitoring and planning at the community level; and data are available to study investigators for analyses and scientific evaluation.

Parallel particle impactor - novel size-selective particle sampler for accurate fractioning of inhalable particles

NASA Astrophysics Data System (ADS)

Trakumas, S.; Salter, E.

2009-02-01

Adverse health effects due to exposure to airborne particles are associated with particle deposition within the human respiratory tract. Particle size, shape, chemical composition, and the individual physiological characteristics of each person determine to what depth inhaled particles may penetrate and deposit within the respiratory tract. Various particle inertial classification devices are available to fractionate airborne particles according to their aerodynamic size to approximate particle penetration through the human respiratory tract. Cyclones are most often used to sample thoracic or respirable fractions of inhaled particles. Extensive studies of different cyclonic samplers have shown, however, that the sampling characteristics of cyclones do not follow the entire selected convention accurately. In the search for a more accurate way to assess worker exposure to different fractions of inhaled dust, a novel sampler comprising several inertial impactors arranged in parallel was designed and tested. The new design includes a number of separated impactors arranged in parallel. Prototypes of respirable and thoracic samplers each comprising four impactors arranged in parallel were manufactured and tested. Results indicated that the prototype samplers followed closely the penetration characteristics for which they were designed. The new samplers were found to perform similarly for liquid and solid test particles; penetration characteristics remained unchanged even after prolonged exposure to coal mine dust at high concentration. The new parallel impactor design can be applied to approximate any monotonically decreasing penetration curve at a selected flow rate. Personal-size samplers that operate at a few L/min as well as area samplers that operate at higher flow rates can be made based on the suggested design. Performance of such samplers can be predicted with high accuracy employing well-established impaction theory.

Electromagnetic Design of a Magnetically-Coupled Spatial Power Combiner

NASA Technical Reports Server (NTRS)

Bulcha, B.; Cataldo, G.; Stevenson, T. R.; U-Yen, K.; Moseley, S. H.; Wollack, E. J.

2017-01-01

The design of a two-dimensional beam-combining network employing a parallel-plate superconducting waveguide with a mono-crystalline silicon dielectric is presented. This novel beam-combining network structure employs an array of magnetically coupled antenna elements to achieve high coupling efficiency and full sampling of the intensity distribution while avoiding diffractive losses in the multi-mode region defined by the parallel-plate waveguide. These attributes enable the structures use in realizing compact far-infrared spectrometers for astrophysical and instrumentation applications. When configured with a suitable corporate-feed power-combiner, this fully sampled array can be used to realize a low-sidelobe apodized response without incurring a reduction in coupling efficiency. To control undesired reflections over a wide range of angles in the finite-sized parallel-plate waveguide region, a wideband meta-material electromagnetic absorber structure is implemented. This adiabatic structure absorbs greater than 99 of the power over the 1.7:1 operational band at angles ranging from normal (0 degree) to near parallel (180 degree) incidence. Design, simulations, and application of the device will be presented.

Multi-GPU parallel algorithm design and analysis for improved inversion of probability tomography with gravity gradiometry data

NASA Astrophysics Data System (ADS)

Hou, Zhenlong; Huang, Danian

2017-09-01

In this paper, we make a study on the inversion of probability tomography (IPT) with gravity gradiometry data at first. The space resolution of the results is improved by multi-tensor joint inversion, depth weighting matrix and the other methods. Aiming at solving the problems brought by the big data in the exploration, we present the parallel algorithm and the performance analysis combining Compute Unified Device Architecture (CUDA) with Open Multi-Processing (OpenMP) based on Graphics Processing Unit (GPU) accelerating. In the test of the synthetic model and real data from Vinton Dome, we get the improved results. It is also proved that the improved inversion algorithm is effective and feasible. The performance of parallel algorithm we designed is better than the other ones with CUDA. The maximum speedup could be more than 200. In the performance analysis, multi-GPU speedup and multi-GPU efficiency are applied to analyze the scalability of the multi-GPU programs. The designed parallel algorithm is demonstrated to be able to process larger scale of data and the new analysis method is practical.

Predicting the stability of a compressible periodic parallel jet flow

NASA Technical Reports Server (NTRS)

Miles, Jeffrey H.

1996-01-01

It is known that mixing enhancement in compressible free shear layer flows with high convective Mach numbers is difficult. One design strategy to get around this is to use multiple nozzles. Extrapolating this design concept in a one dimensional manner, one arrives at an array of parallel rectangular nozzles where the smaller dimension is omega and the longer dimension, b, is taken to be infinite. In this paper, the feasibility of predicting the stability of this type of compressible periodic parallel jet flow is discussed. The problem is treated using Floquet-Bloch theory. Numerical solutions to this eigenvalue problem are presented. For the case presented, the interjet spacing, s, was selected so that s/omega =2.23. Typical plots of the eigenvalue and stability curves are presented. Results obtained for a range of convective Mach numbers from 3 to 5 show growth rates omega(sub i)=kc(sub i)/2 range from 0.25 to 0.29. These results indicate that coherent two-dimensional structures can occur without difficulty in multiple parallel periodic jet nozzles and that shear layer mixing should occur with this type of nozzle design.

Directions in parallel programming: HPF, shared virtual memory and object parallelism in pC++

NASA Technical Reports Server (NTRS)

Bodin, Francois; Priol, Thierry; Mehrotra, Piyush; Gannon, Dennis

1994-01-01

Fortran and C++ are the dominant programming languages used in scientific computation. Consequently, extensions to these languages are the most popular for programming massively parallel computers. We discuss two such approaches to parallel Fortran and one approach to C++. The High Performance Fortran Forum has designed HPF with the intent of supporting data parallelism on Fortran 90 applications. HPF works by asking the user to help the compiler distribute and align the data structures with the distributed memory modules in the system. Fortran-S takes a different approach in which the data distribution is managed by the operating system and the user provides annotations to indicate parallel control regions. In the case of C++, we look at pC++ which is based on a concurrent aggregate parallel model.

OpenCL: A Parallel Programming Standard for Heterogeneous Computing Systems.

PubMed

Stone, John E; Gohara, David; Shi, Guochun

2010-05-01

We provide an overview of the key architectural features of recent microprocessor designs and describe the programming model and abstractions provided by OpenCL, a new parallel programming standard targeting these architectures.

The design of multi-core DSP parallel model based on message passing and multi-level pipeline

NASA Astrophysics Data System (ADS)

Niu, Jingyu; Hu, Jian; He, Wenjing; Meng, Fanrong; Li, Chuanrong

2017-10-01

Currently, the design of embedded signal processing system is often based on a specific application, but this idea is not conducive to the rapid development of signal processing technology. In this paper, a parallel processing model architecture based on multi-core DSP platform is designed, and it is mainly suitable for the complex algorithms which are composed of different modules. This model combines the ideas of multi-level pipeline parallelism and message passing, and summarizes the advantages of the mainstream model of multi-core DSP (the Master-Slave model and the Data Flow model), so that it has better performance. This paper uses three-dimensional image generation algorithm to validate the efficiency of the proposed model by comparing with the effectiveness of the Master-Slave and the Data Flow model.

A Randomized Double-Blind, Double-Dummy, Multicenter Trial of Azasetron versus Ondansetron to Evaluate Efficacy and Safety in the Prevention of Delayed Nausea and Vomiting Induced by Chemotherapy

PubMed Central

Lee, Hee Yeon; Lee, Kyung Hee; Kim, Bong-Seog; Song, Hong Suk; Yang, Sung Hyun; Kim, Joon Hee; Kim, Yeul Hong; Kim, Jong Gwang; Kim, Sang-We; Kim, Dong-Wan; Kim, Si-Young; Park, Hee Sook

2014-01-01

Purpose This study was conducted to evaluate the efficacy and safety of azasetron compared to ondansetron in the prevention of delayed chemotherapy-induced nausea and vomiting. Materials and Methods This study was a multi-center, prospective, randomized, double-dummy, double-blind and parallel-group trial involving 12 institutions in Korea between May 2005 and December 2005. A total of 265 patients with moderately and highly emetogenic chemotherapy were included and randomly assigned to either the azasetron or ondansetron group. All patients received azasetron (10 mg intravenously) and dexamethasone (20 mg intravenously) on day 1 and dexamethasone (4 mg orally every 12 hours) on days 2-4. The azasetron group received azasetron (10 mg orally) with placebo of ondansetron (orally every 12 hours), and the ondansetron group received ondansetron (8 mg orally every 12 hours) with placebo of azasetron (orally) on days 2-6. Results Over days 2-6, the effective ratio of complete response in the azasetron and ondansetron groups was 45% and 54.5%, respectively (95% confidence interval, -21.4 to 2.5%). Thus, the non-inferiority of azasetron compared with ondansetron in delayed chemotherapy-induced nausea and vomiting was not proven in the present study. All treatments were well tolerated and no unexpected drug-related adverse events were reported. The most common adverse events related to the treatment were constipation and hiccups, and there were no differences in the overall incidence of adverse events. Conclusion In the present study, azasetron showed inferiority in the control of delayed chemotherapy-induced nausea and vomiting compared with ondansetron whereas safety profiles were similar between the two groups. PMID:24520219

Phase 2a, randomized, double-blind, placebo-controlled, multicenter, parallel-group study of a H4 R-antagonist (JNJ-39758979) in Japanese adults with moderate atopic dermatitis.

PubMed

Murata, Yoko; Song, Michael; Kikuchi, Hisayuki; Hisamichi, Katsuya; Xu, Xie L; Greenspan, Andrew; Kato, Mai; Chiou, Chiun-Fang; Kato, Takeshi; Guzzo, Cynthia; Thurmond, Robin L; Ohtsuki, Mamitaro; Furue, Masutaka

2015-02-01

This trial was conducted to evaluate the safety and efficacy of the H4 R-antagonist JNJ-39758979 in adult Japanese patients with moderate atopic dermatitis (AD). Eligible patients were randomly assigned to JNJ-39758979 300 mg, 100 mg or placebo once daily for 6 weeks in this phase 2a, double-blind, multicenter, placebo-controlled study. Primary efficacy was assessed via week-6 Eczema Area and Severity Index (EASI) scores. Secondary efficacy assessments included Investigator's Global Assessment (IGA) and patient-reported outcome (PRO) pruritus assessments (Pruritus Categorical Response Scale [PCRS], Pruritus Numeric Rating Scales [PNRS], Pruritus Interference Numeric Rating Scale [PINRS] and Subject's Global Impressions of Change in Pruritus [SGICP]). Eighty-eight of 105 planned patients were randomized before the study was stopped and unblinded for safety reasons. The study did not meet the primary end-point. However, numerical improvements (i.e. decreases) in median EASI were observed with JNJ-39758979 100 mg (-3.7) and 300 mg (-3.0) versus placebo (-1.3) at week 6. Nominally significant improvements across PRO PCRS, PNRS and SGICP assessments were consistently observed, particularly with JNJ-39758979 300 mg. Safety, including adverse events (AE), was comparable between JNJ-39758979 and placebo with the exception of two patients (both receiving JNJ-39758979 300 mg) with serious AE of neutropenia, leading to premature study discontinuation. No deaths were reported. Except for neutropenia, no clinically relevant changes in laboratory values were observed. Although not conclusive, findings suggest H4 R-antagonism may be beneficial for AD, particularly in controlling pruritus. JNJ-39758979 appears to be associated with drug-induced agranulocytosis, likely an off-target effect. © 2014 Japanese Dermatological Association.

[A prospective multicenter randomized controlled clinical study on the efficacy and safety of Guaifenesin compound pseudoephedrine hydrochloride oral solution].

PubMed

Lu, Quan

2010-03-01

To evaluate efficacy and safety of Guaifenesin compound pseudoephedrine hydrochloride oral solution for the treatment of cough, expectoration, nasal congestion and runny nose in children. This was a prospective multicenter randomized single-blind, parallel-controlled clinical study. A total of 10 centers participated in this study, the actual number of cases in line with the program was 412, of whom 205 cases in trial group were treated with Guaifenesin compound pseudoephedrine hydrochloride oral solution, and 207 cases in control group with ambroxol hydrochloride oral solution, treatment of both groups persisted for 7 days. The improvement rate of each single symptom and the combined symptoms and the overall effective rate were compared between the two groups. The adverse drug reactions and compliance were assessed as well. The treatment of both groups showed efficacy. Except sputum stickiness, the improvement of all symptoms in trial group was superior to that in the control group on the 3rd day after treatment (P < 0.05) and except nasal congestion, the efficacy in all the other symptoms of trial group was better than that in the control group as well on the 7th day (P < 0.01). The improvement rate for combined symptoms of Guaifenesin compound pseudoephedrine hydrochloride oral solution was 82.9% and the overall efficacy rate was 89.3%. Guaifenesin compound Pseudoephedrine hydrochloride oral solution had higher compliance and its adverse event rate was merely 0.92%. Guaifenesin compound pseudoephedrine hydrochloride oral solution showed significant efficacy and safety in children for treatment of cough, expectoration, nasal congestion and runny nose caused by common cold or acute tracheobronchitis.

Efficacy and safety of 1 % terbinafine film-forming solution in Chinese patients with tinea pedis: a randomized, double-blind, placebo-controlled, multicenter, parallel-group study.

PubMed

Li, Ruo Yu; Wang, A P; Xu, J H; Xi, L Y; Fu, M H; Zhu, M; Xu, M L; Li, X Q; Lai, W; Liu, W D; Lu, X Y; Gong, Z Q

2014-03-01

Superficial fungal skin infections are treated using topical antifungals. The aim of this study was to demonstrate the efficacy of a single application of 1 % terbinafine film-forming solution (FFS) versus placebo for the treatment of tinea pedis in the Chinese population. Six centers in China randomized 290 patients in a 1:1 ratio to receive either 1 % terbinafine FFS or FFS vehicle (placebo) once on the affected foot/feet. Efficacy assessments included microscopy and mycologic culture, and assessing clinical signs and symptoms at baseline, and at weeks 1 and 6 after the topical treatment. All adverse events were recorded. At week 6, 1 % terbinafine FFS was superior to placebo for effective treatment rate (63 vs. 8 %); clinical cure (30 vs. 6 %); mycological cure (86 vs. 12 %); negative microscopy (90 vs. 24 %); and negative mycological culture (90 vs. 27 %): all p ≤ 0.001 and clinically relevant. At week 6, 1 % terbinafine FFS was clinically superior to placebo for the absence of: erythema (69 vs. 29 %); desquamation (33 vs. 8 %); and pruritus (70 vs. 30 %): all p ≤ 0.001 and clinically relevant. At week 6, differences in the average total signs and symptoms scores were significantly lower for 1 % terbinafine FFS versus placebo (p ≤ 0.001). Both 1 % terbinafine FFS and placebo were safe and well tolerated based on adverse events and investigator and patient assessments. This double-blind, randomized, multicenter study demonstrated one single topical application of 1 % terbinafine FFS was safe and effective in the treatment of tinea pedis in the Chinese population.

Efficacy and safety of rifaximin in Japanese patients with hepatic encephalopathy: A phase II/III, multicenter, randomized, evaluator-blinded, active-controlled trial and a phase III, multicenter, open trial.

PubMed

Suzuki, Kazuyuki; Endo, Ryujin; Takikawa, Yasuhiro; Moriyasu, Fuminori; Aoyagi, Yutaka; Moriwaki, Hisataka; Terai, Shuji; Sakaida, Isao; Sakai, Yoshiyuki; Nishiguchi, Shuhei; Ishikawa, Toru; Takagi, Hitoshi; Naganuma, Atsushi; Genda, Takuya; Ichida, Takafumi; Takaguchi, Koichi; Miyazawa, Katsuhiko; Okita, Kiwamu

2018-05-01

The efficacy and safety of rifaximin in the treatment of hepatic encephalopathy (HE) are widely known, but they have not been confirmed in Japanese patients with HE. Thus, two prospective, randomized studies (a phase II/III study and a phase III study) were carried out. Subjects with grade I or II HE and hyperammonemia were enrolled. The phase II/III study, which was a randomized, evaluator-blinded, active-comparator, parallel-group study, was undertaken at 37 institutions in Japan. Treatment periods were 14 days. Eligible patients were randomized to the rifaximin group (1200 mg/day) or the lactitol group (18-36 g/day). The phase III study was carried out in the same patients previously enrolled in the phase II/III study, and they were all treated with rifaximin (1200 mg/day) for 10 weeks. In the phase II/III study, 172 patients were enrolled. Blood ammonia (B-NH 3 ) concentration was significantly improved in the rifaximin group, but the difference between the two groups was not significant. The portal systemic encephalopathy index (PSE index), including HE grade, was significantly improved in both groups. In the phase III study, 87.3% of enrolled patients completed the treatment. The improved B-NH 3 concentration and PSE index were well maintained from the phase II/III study during the treatment period of the phase III study. Adverse drug reactions (ADRs) were seen in 13.4% of patients who received rifaximin, but there were no severe ADRs leading to death. The efficacy of rifaximin is sufficient and treatment is well tolerated in Japanese patients with HE and hyperammonemia. © 2017 The Japan Society of Hepatology.

Efficacy and safety of febuxostat for prevention of tumor lysis syndrome in patients with malignant tumors receiving chemotherapy: a phase III, randomized, multi-center trial comparing febuxostat and allopurinol.

PubMed

Tamura, Kazuo; Kawai, Yasukazu; Kiguchi, Toru; Okamoto, Masataka; Kaneko, Masahiko; Maemondo, Makoto; Gemba, Kenichi; Fujimaki, Katsumichi; Kirito, Keita; Goto, Tetsuya; Fujisaki, Tomoaki; Takeda, Kenji; Nakajima, Akihiro; Ueda, Takanori

2016-10-01

Control of serum uric acid (sUA) levels is very important during chemotherapy in patients with malignant tumors, as the risks of tumor lysis syndrome (TLS) and renal events are increased with increasing levels of sUA. We investigated the efficacy and safety of febuxostat, a potent non-purine xanthine oxidase inhibitor, compared with allopurinol for prevention of hyperuricemia in patients with malignant tumors, including solid tumors, receiving chemotherapy in Japan. An allopurinol-controlled multicenter, open-label, randomized, parallel-group comparative study was carried out. Patients with malignant tumors receiving chemotherapy, who had an intermediate risk of TLS or a high risk of TLS and were not scheduled to be treated with rasburicase, were enrolled and then randomized to febuxostat (60 mg/day) or allopurinol (300 or 200 mg/day). All patients started to take the study drug 24 h before chemotherapy. The primary objective was to confirm the non-inferiority of febuxostat to allopurinol based on the area under the curve (AUC) of sUA for a 6-day treatment period. Forty-nine and 51 patients took febuxostat and allopurinol, respectively. sUA decreased over time after initiation of study treatment. The least squares mean difference of the AUC of sUA between the treatment groups was -33.61 mg h/dL, and the 95 % confidence interval was -70.67 to 3.45, demonstrating the non-inferiority of febuxostat to allopurinol. No differences were noted in safety outcomes between the treatment groups. Febuxostat demonstrated an efficacy and safety similar to allopurinol in patients with malignant tumors receiving chemotherapy. http://www.clinicaltrials.jp ; Identifier: JapicCTI-132398.

Efficacy and safety of bilastine in Japanese patients with chronic spontaneous urticaria: A multicenter, randomized, double-blind, placebo-controlled, parallel-group phase II/III study.

PubMed

Hide, Michihiro; Yagami, Akiko; Togawa, Michinori; Saito, Akihiro; Furue, Masutaka

2017-04-01

Bilastine, a novel non-sedating second-generation H 1 -antihistamine, has been widely used in the treatment of allergic rhinoconjunctivitis and urticaria with a recommended dose of 20 mg once daily in most European countries since 2010. We evaluated its efficacy and safety in Japanese patients with chronic spontaneous urticaria (CSU). We conducted a multicenter, randomized, double-blind, placebo-controlled phase II/III study (trial registration No. JapicCTI-142574). Patients (age, 18-74 years) were randomly assigned to receive bilastine 20 mg, 10 mg or placebo once daily for 2 weeks. The primary efficacy endpoint was the change from baseline (Day -3 to 0) in total symptom score (TSS) at 2 weeks (Day 8-14), consisting of the itch and rash scores. A total of 304 patients were randomly allocated to bilastine 20 mg (101 patients), bilastine 10 mg (100 patients), and placebo (103 patients). The changes in TSS at 2 weeks were significantly decreased by bilastine 20 mg than did placebo (p < 0.001), demonstrating the superiority of bilastine 20 mg. Bilastine 10 mg also showed a significant difference from placebo (p < 0.001). The TSS changes for the bilastine showed significant improvement from Day 1, and were maintained during the treatment period. The Dermatology Life Quality Index scores were also improved in bilastine than in placebo. The bilastine treatments were safe and well tolerated. Two-week treatment with bilastine (20 or 10 mg) once daily was effective and tolerable in Japanese patients with CSU, demonstrating an early onset of action. Copyright © 2016 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

Are written information or counseling (WOMAN-PRO II program) able to improve patient satisfaction and the delivery of health care of women with vulvar neoplasms? Secondary outcomes of a multicenter randomized controlled trial

PubMed

Gehrig, Larissa; Kobleder, Andrea; Werner, Birgit; Denhaerynck, Kris; Senn, Beate

2017-01-01

Background: Patients with vulvar neoplasms report a lack of information, missing support in self-management and a gap in delivery of health care. Aim: The aim of the study was to investigate if written information or counseling based on the WOMAN-PRO II program are able to improve patient satisfaction and the delivery of health care from the health professional's perspective of women with vulvar neoplasms. Method: Patient satisfaction and the delivery of health care have been investigated as two secondary outcomes in a multicenter randomized controlled parallel-group phase II study (Clinical Trial ID: NCT01986725). In total, 49 women, from four hospitals (CH, AUT), completed the questionnaire PACIC-S11 after written information (n = 13) and counseling (n = 36). The delivery of health care was evaluated by ten Advanced Practice Nurses (APNs) by using the G-ACIC before and after implementing counseling based on the WOMAN-PRO II program. Results: There were no significant differences between the two groups identified (p = 0.25). Only few aspects were rated highly by all women, such as the overall satisfaction (M = 80.3 %) and satisfaction with organization of care (M = 83.0 %). The evaluation of delivery of health care by APNs in women who received counseling improved significantly (p = 0.031). Conclusions: There are indications, that the practice of both interventions might have improved patient satisfaction and counseling the delivery of health care. The aspects that have been rated low in the PACIC-S11 and G-ACIC indicate possibilities to optimize the delivery of health care.

Efficacy and safety of pentavalent rotavirus vaccine in Japan: a randomized, double-blind, placebo-controlled, multicenter trial.

PubMed

Iwata, Satoshi; Nakata, Shuji; Ukae, Susumu; Koizumi, Yoshitugu; Morita, Yasuyuki; Kuroki, Haruo; Tanaka, Yoshiyuki; Shizuya, Toshiyuki; Schödel, Florian; Brown, Michelle L; Lawrence, Jody

2013-08-01

Rotavirus is the most common cause of severe gastroenteritis in children under 5 y of age. Estimates of disease burden in Japan suggest that between 26,500 and 78,000 children in this age group need hospitalization each year, resulting in a direct medical cost of 10 to 24 billion Yen. Since being introduced in routine infant immunization schedules in the United States in 2006, the oral live pentavalent rotavirus vaccine RV5 (RotaTeq™) has contributed to dramatic reductions in the incidence of rotavirus gastroenteritis (RVGE) and in health care resource utilization. This was a multicenter, randomized, double-blind, placebo-controlled, parallel-group study to evaluate the efficacy and safety of a 3-dose regimen of RV5 in healthy infants, age 6 to 12 weeks, at 32 sites across Japan. The results indicate that RV5 was significantly efficacious in preventing any severity [74.5% (95% confidence interval [CI]: 39.9%, 90.6%; p<0.001)], moderate-to-severe [80.2% (95% CI: 47.4%, 94.1%)], and severe [100% (95% CI: 55.4%, 100%)] RVGE caused by viruses with serotypes contained in the vaccine. The observed cases of RVGE included rotavirus types G1 (n=19), G3 (n=9), G9 (n=5) and one unspecified G serotype with P1A[8]. No G2 or G4 RVGE cases were observed, and this study was not powered to evaluate efficacy against individual serotypes. RV5 was generally safe and well tolerated in Japanese infants. These results are comparable to those observed in clinical studies conducted in other developed countries. Introduction of the vaccine in Japan may reduce disease burden and associated health care costs.

2.4 g Mesalamine (Asacol 400 mg tablet) Once Daily is as Effective as Three Times Daily in Maintenance of Remission in Ulcerative Colitis: A Randomized, Noninferiority, Multi-center Trial.

PubMed

Suzuki, Yasuo; Iida, Mitsuo; Ito, Hiroaki; Nishino, Haruo; Ohmori, Toshihide; Arai, Takehiro; Yokoyama, Tadashi; Okubo, Takanori; Hibi, Toshifumi

2017-05-01

The noninferiority of pH-dependent release mesalamine (Asacol) once daily (QD) to 3 times daily (TID) administration was investigated. This was a phase 3, multicenter, randomized, double-blind, parallel-group, active-control study, with dynamic and stochastic allocation using central registration. Patients with ulcerative colitis in remission (a bloody stool score of 0, and an ulcerative colitis disease activity index of ≤2), received the study drug (Asacol 2.4 g/d) for 48 weeks. The primary efficacy endpoint of the nonrecurrence rate was assessed on the full analysis set. The noninferiority margin was 10%. Six hundred and four subjects were eligible and were allocated; 603 subjects received the study drug. The full analysis set comprised 602 subjects (QD: 301, TID: 301). Nonrecurrence rates were 88.4% in the QD and 89.6% in the TID. The difference between nonrecurrence rates was -1.3% (95% confidence interval: -6.2, 3.7), confirming noninferiority. No differences in the safety profile were observed between the two treatment groups. On post hoc analysis by integrating the QD and the TID, nonrecurrence rate with a mucosal appearance score of 0 at determination of eligibility was significantly higher than the score of 1. The mean compliance rates were 97.7% in the QD and 98.1% in the TID. QD dosing with Asacol is as effective and safe as TID for maintenance of remission in patients with ulcerative colitis. Additionally, this study indicated that maintaining a good mucosal state is the key for longer maintenance of remission.

2.4 g Mesalamine (Asacol 400 mg tablet) Once Daily is as Effective as Three Times Daily in Maintenance of Remission in Ulcerative Colitis: A Randomized, Noninferiority, Multi-center Trial

PubMed Central

Suzuki, Yasuo; Iida, Mitsuo; Ito, Hiroaki; Nishino, Haruo; Ohmori, Toshihide; Arai, Takehiro; Yokoyama, Tadashi; Okubo, Takanori

2017-01-01

Background: The noninferiority of pH-dependent release mesalamine (Asacol) once daily (QD) to 3 times daily (TID) administration was investigated. Methods: This was a phase 3, multicenter, randomized, double-blind, parallel-group, active-control study, with dynamic and stochastic allocation using central registration. Patients with ulcerative colitis in remission (a bloody stool score of 0, and an ulcerative colitis disease activity index of ≤2), received the study drug (Asacol 2.4 g/d) for 48 weeks. The primary efficacy endpoint of the nonrecurrence rate was assessed on the full analysis set. The noninferiority margin was 10%. Results: Six hundred and four subjects were eligible and were allocated; 603 subjects received the study drug. The full analysis set comprised 602 subjects (QD: 301, TID: 301). Nonrecurrence rates were 88.4% in the QD and 89.6% in the TID. The difference between nonrecurrence rates was −1.3% (95% confidence interval: −6.2, 3.7), confirming noninferiority. No differences in the safety profile were observed between the two treatment groups. On post hoc analysis by integrating the QD and the TID, nonrecurrence rate with a mucosal appearance score of 0 at determination of eligibility was significantly higher than the score of 1. The mean compliance rates were 97.7% in the QD and 98.1% in the TID. Conclusions: QD dosing with Asacol is as effective and safe as TID for maintenance of remission in patients with ulcerative colitis. Additionally, this study indicated that maintaining a good mucosal state is the key for longer maintenance of remission. PMID:28368909

Toward the Standardization of Mycological Examination of Sputum Samples in Cystic Fibrosis: Results from a French Multicenter Prospective Study.

PubMed

Coron, Noémie; Pihet, Marc; Fréalle, Emilie; Lemeille, Yolande; Pinel, Claudine; Pelloux, Hervé; Gargala, Gilles; Favennec, Loic; Accoceberry, Isabelle; Durand-Joly, Isabelle; Dalle, Frédéric; Huet, Frédéric; Fanton, Annlyse; Boldron, Amale; Loeuille, Guy-André; Domblides, Philippe; Coltey, Bérengère; Pin, Isabelle; Llerena, Catherine; Troussier, Françoise; Person, Christine; Marguet, Christophe; Wizla, Nathalie; Thumerelle, Caroline; Turck, Dominique; Bui, Stéphanie; Fayon, Michael; Duhamel, Alain; Prévotat, Anne; Wallaert, Benoit; Leroy, Sylvie; Bouchara, Jean-Philippe; Delhaes, Laurence

2018-02-01

Fungal respiratory colonization of cystic fibrosis (CF) patients emerges as a new concern; however, the heterogeneity of mycological protocols limits investigations. We first aimed at setting up an efficient standardized protocol for mycological analysis of CF sputa that was assessed during a prospective, multicenter study: "MucoFong" program (PHRC-06/1902). Sputa from 243 CF patients from seven centers in France were collected over a 15-month period and submitted to a standardized protocol based on 6 semi-selective media. After mucolytic pretreatment, sputa were plated in parallel on cycloheximide-enriched (ACT37), erythritol-enriched (ERY37), benomyl dichloran-rose bengal (BENO37) and chromogenic (CAN37) media incubated at 37 °C and on Sabouraud-chloramphenicol (SAB27) and erythritol-enriched (ERY27) media incubated at 20-27 °C. Each plate was checked twice a week during 3 weeks. Fungi were conventionally identified; time for detection of fungal growth was noted for each species. Fungal prevalences and media performances were assessed; an optimal combination of media was determined using the Chi-squared automatic interaction detector method. At least one fungal species was isolated from 81% of sputa. Candida albicans was the most prevalent species (58.8%), followed by Aspergillus fumigatus (35.4%). Cultivation on CAN37, SAB27, ACT37 and ERY27 during 16 days provided an optimal combination, detecting C. albicans, A. fumigatus, Scedosporium apiospermum complex and Exophiala spp. with sensitivities of 96.5, 98.8, 100 and 100%. Combination of these four culture media is recommended to ensure the growth of key fungal pathogens in CF respiratory specimens. The use of such consensual protocol is of major interest for merging results from future epidemiological studies.

Aerodynamic Shape Optimization of Supersonic Aircraft Configurations via an Adjoint Formulation on Parallel Computers

NASA Technical Reports Server (NTRS)

Reuther, James; Alonso, Juan Jose; Rimlinger, Mark J.; Jameson, Antony

1996-01-01

This work describes the application of a control theory-based aerodynamic shape optimization method to the problem of supersonic aircraft design. The design process is greatly accelerated through the use of both control theory and a parallel implementation on distributed memory computers. Control theory is employed to derive the adjoint differential equations whose solution allows for the evaluation of design gradient information at a fraction of the computational cost required by previous design methods (13, 12, 44, 38). The resulting problem is then implemented on parallel distributed memory architectures using a domain decomposition approach, an optimized communication schedule, and the MPI (Message Passing Interface) Standard for portability and efficiency. The final result achieves very rapid aerodynamic design based on higher order computational fluid dynamics methods (CFD). In our earlier studies, the serial implementation of this design method (19, 20, 21, 23, 39, 25, 40, 41, 42, 43, 9) was shown to be effective for the optimization of airfoils, wings, wing-bodies, and complex aircraft configurations using both the potential equation and the Euler equations (39, 25). In our most recent paper, the Euler method was extended to treat complete aircraft configurations via a new multiblock implementation. Furthermore, during the same conference, we also presented preliminary results demonstrating that the basic methodology could be ported to distributed memory parallel computing architectures [241. In this paper, our concem will be to demonstrate that the combined power of these new technologies can be used routinely in an industrial design environment by applying it to the case study of the design of typical supersonic transport configurations. A particular difficulty of this test case is posed by the propulsion/airframe integration.

SCORPIO: A Scalable Two-Phase Parallel I/O Library With Application To A Large Scale Subsurface Simulator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sreepathi, Sarat; Sripathi, Vamsi; Mills, Richard T

2013-01-01

Inefficient parallel I/O is known to be a major bottleneck among scientific applications employed on supercomputers as the number of processor cores grows into the thousands. Our prior experience indicated that parallel I/O libraries such as HDF5 that rely on MPI-IO do not scale well beyond 10K processor cores, especially on parallel file systems (like Lustre) with single point of resource contention. Our previous optimization efforts for a massively parallel multi-phase and multi-component subsurface simulator (PFLOTRAN) led to a two-phase I/O approach at the application level where a set of designated processes participate in the I/O process by splitting themore » I/O operation into a communication phase and a disk I/O phase. The designated I/O processes are created by splitting the MPI global communicator into multiple sub-communicators. The root process in each sub-communicator is responsible for performing the I/O operations for the entire group and then distributing the data to rest of the group. This approach resulted in over 25X speedup in HDF I/O read performance and 3X speedup in write performance for PFLOTRAN at over 100K processor cores on the ORNL Jaguar supercomputer. This research describes the design and development of a general purpose parallel I/O library, SCORPIO (SCalable block-ORiented Parallel I/O) that incorporates our optimized two-phase I/O approach. The library provides a simplified higher level abstraction to the user, sitting atop existing parallel I/O libraries (such as HDF5) and implements optimized I/O access patterns that can scale on larger number of processors. Performance results with standard benchmark problems and PFLOTRAN indicate that our library is able to maintain the same speedups as before with the added flexibility of being applicable to a wider range of I/O intensive applications.« less

Reliability of 3-Dimensional Measures of Single-Leg Cross Drop Landing Across 3 Different Institutions

PubMed Central

DiCesare, Christopher A.; Bates, Nathaniel A.; Barber Foss, Kim D.; Thomas, Staci M.; Wordeman, Samuel C.; Sugimoto, Dai; Roewer, Benjamin D.; Medina McKeon, Jennifer M.; Di Stasi, Stephanie; Noehren, Brian W.; Ford, Kevin R.; Kiefer, Adam W.; Hewett, Timothy E.; Myer, Gregory D.

2015-01-01

Background: Anterior cruciate ligament (ACL) injuries are physically and financially devastating but affect a relatively small percentage of the population. Prospective identification of risk factors for ACL injury necessitates a large sample size; therefore, study of this injury would benefit from a multicenter approach. Purpose: To determine the reliability of kinematic and kinetic measures of a single-leg cross drop task across 3 institutions. Study Design: Controlled laboratory study. Methods: Twenty-five female high school volleyball players participated in this study. Three-dimensional motion data of each participant performing the single-leg cross drop were collected at 3 institutions over a period of 4 weeks. Coefficients of multiple correlation were calculated to assess the reliability of kinematic and kinetic measures during the landing phase of the movement. Results: Between-centers reliability for kinematic waveforms in the frontal and sagittal planes was good, but moderate in the transverse plane. Between-centers reliability for kinetic waveforms was good in the sagittal, frontal, and transverse planes. Conclusion: Based on these findings, the single-leg cross drop task has moderate to good reliability of kinematic and kinetic measures across institutions after implementation of a standardized testing protocol. Clinical Relevance: Multicenter collaborations can increase study numbers and generalize results, which is beneficial for studies of relatively rare phenomena, such as ACL injury. An important step is to determine the reliability of risk assessments across institutions before a multicenter collaboration can be initiated. PMID:26779550

Symposium on Parallel Computational Methods for Large-scale Structural Analysis and Design, 2nd, Norfolk, VA, US

NASA Technical Reports Server (NTRS)

Storaasli, Olaf O. (Editor); Housner, Jerrold M. (Editor)

1993-01-01

Computing speed is leaping forward by several orders of magnitude each decade. Engineers and scientists gathered at a NASA Langley symposium to discuss these exciting trends as they apply to parallel computational methods for large-scale structural analysis and design. Among the topics discussed were: large-scale static analysis; dynamic, transient, and thermal analysis; domain decomposition (substructuring); and nonlinear and numerical methods.

Program For Parallel Discrete-Event Simulation

NASA Technical Reports Server (NTRS)

Beckman, Brian C.; Blume, Leo R.; Geiselman, John S.; Presley, Matthew T.; Wedel, John J., Jr.; Bellenot, Steven F.; Diloreto, Michael; Hontalas, Philip J.; Reiher, Peter L.; Weiland, Frederick P.

1991-01-01

User does not have to add any special logic to aid in synchronization. Time Warp Operating System (TWOS) computer program is special-purpose operating system designed to support parallel discrete-event simulation. Complete implementation of Time Warp mechanism. Supports only simulations and other computations designed for virtual time. Time Warp Simulator (TWSIM) subdirectory contains sequential simulation engine interface-compatible with TWOS. TWOS and TWSIM written in, and support simulations in, C programming language.

Joint Experiment on Scalable Parallel Processors (JESPP) Parallel Data Management

DTIC Science & Technology

2006-05-01

management and analysis tool, called Simulation Data Grid ( SDG ). The design principles driving the design of SDG are: 1) minimize network communication...or SDG . In this report, an initial prototype implementation of this system is described. This project follows on earlier research, primarily...distributed logging system had some 2 limitations. These limitations will be described in this report, and how the SDG addresses these limitations. 3.0

Further enhancement of facial appearance with a hydroquinone skin care system plus tretinoin in patients previously treated with botulinum toxin Type A.

PubMed

Schlessinger, Joel; Kenkel, Jeffrey; Werschler, Philip

2011-07-01

A hydroquinone (HQ) skin care system has been designed for use in conjunction with nonsurgical procedures. The authors evaluate the efficacy of this system plus tretinoin for improving facial appearance in comparison to a standard skin care regimen in users of botulinum toxin Type A (BoNT-A). In this multicenter, randomized, investigator-masked, parallel-group study, 61 patients who received upper facial treatment with BoNT-A at a plastic surgery or dermatology clinic were randomly assigned to apply either the HQ system (cleanser, toner, proprietary 4% hydroquinone, exfoliant, and sunscreen) plus 0.05% tretinoin cream or a standard skin care regimen (cleanser, moisturizer, and sunscreen) for 120 days. Outcomes were assessed by the investigators and through a patient questionnaire. Compared with standard skin care, the HQ system plus tretinoin resulted in significantly milder fine lines/wrinkles and hyperpigmentation at Days 30, 90, and 120 (p ≤ .05) and significantly superior overall ratings for each of nine patient assessments at Days 90 and 120 (p ≤ .05). A relatively greater proportion of patients using the HQ system plus tretinoin believed that their study treatment had further enhanced the improvements attained with BoNT-A (86% vs 8%). Both regimens were generally well tolerated. Adjunctive use of the HQ system plus tretinoin can further enhance the improvements in facial appearance attained with BoNT-A. Applying the HQ system plus tretinoin offers multiple clinical benefits over standard skin care, including significantly greater improvements in fine lines/wrinkles and hyperpigmentation.

ASPIRE In-Home: rationale, design, and methods of a study to evaluate the safety and efficacy of automatic insulin suspension for nocturnal hypoglycemia.

PubMed

Klonoff, David C; Bergenstal, Richard M; Garg, Satish K; Bode, Bruce W; Meredith, Melissa; Slover, Robert H; Ahmann, Andrew; Welsh, John B; Lee, Scott W

2013-07-01

Nocturnal hypoglycemia is a barrier to therapy intensification efforts in diabetes. The Paradigm® Veo™ system may mitigate nocturnal hypoglycemia by automatically suspending insulin when a prespecified sensor glucose threshold is reached. ASPIRE (Automation to Simulate Pancreatic Insulin REsponse) In-Home (NCT01497938) was a multicenter, randomized, parallel, adaptive study of subjects with type 1 diabetes. The control arm used sensor-augmented pump therapy. The treatment arm used sensor-augmented pump therapy with threshold suspend, which automatically suspends the insulin pump in response to a sensor glucose value at or below a prespecified threshold. To be randomized, subjects had to have demonstrated ≥2 episodes of nocturnal hypoglycemia, defined as >20 consecutive minutes of sensor glucose values ≤65 mg/dl starting between 10:00 PM and 8:00 AM in the 2-week run-in phase. The 3-month study phase evaluated safety by comparing changes in glycated hemoglobin (A1C) values and evaluated efficacy by comparing the mean area under the glucose concentration time curves for nocturnal hypoglycemia events in the two groups. Other outcomes included the rate of nocturnal hypoglycemia events and the distribution of sensor glucose values. Data from the ASPIRE In-Home study should provide evidence on the safety of the threshold suspend feature with respect to A1C and its efficacy with respect to severity and duration of nocturnal hypoglycemia when used at home over a 3-month period. © 2013 Diabetes Technology Society.

Performance of the quantitative food frequency questionnaire used in the Brazilian center of the prospective study Natural History of Human Papillomavirus Infection in Men: The HIM Study.

PubMed

Teixeira, Juliana Araujo; Baggio, Maria Luiza; Giuliano, Anna R; Fisberg, Regina Mara; Marchioni, Dirce Maria Lobo

2011-07-01

The Natural History of Human Papillomavirus (HPV) Infection in Men: The HIM Study is a prospective multicenter cohort study that, among other factors, analyzes participants' diet. A parallel cross-sectional study was designed to evaluate the validity and reproducibility of the quantitative food frequency questionnaire (QFFQ) used in the Brazilian center from the HIM Study. For this, a convenience subsample of 98 men aged 18 to 70 years from the HIM Study in Brazil answered three 54-item QFFQ and three 24-hour recall interviews, with 6-month intervals between them (data collection January to September 2007). A Bland-Altman analysis indicated that the difference between instruments was dependent on the magnitude of the intake for energy and most nutrients included in the validity analysis, with the exception of carbohydrates, fiber, polyunsaturated fat, vitamin C, and vitamin E. The correlation between the QFFQ and the 24-hour recall for the deattenuated and energy-adjusted data ranged from 0.05 (total fat) to 0.57 (calcium). For the energy and nutrients consumption included in the validity analysis, 33.5% of participants on average were correctly classified into quartiles, and the average value of 0.26 for weighted kappa shows a reasonable agreement. The intraclass correlation coefficients for all nutrients were greater than 0.40 in the reproducibility analysis. The QFFQ demonstrated good reproducibility and acceptable validity. The results support the use of this instrument in the HIM Study. Copyright © 2011 American Dietetic Association. Published by Elsevier Inc. All rights reserved.

Modeling and Dynamic Analysis of Paralleled dc/dc Converters With Master-Slave Current Sharing Control

NASA Technical Reports Server (NTRS)

Rajagopalan, J.; Xing, K.; Guo, Y.; Lee, F. C.; Manners, Bruce

1996-01-01

A simple, application-oriented, transfer function model of paralleled converters employing Master-Slave Current-sharing (MSC) control is developed. Dynamically, the Master converter retains its original design characteristics; all the Slave converters are forced to depart significantly from their original design characteristics into current-controlled current sources. Five distinct loop gains to assess system stability and performance are identified and their physical significance is described. A design methodology for the current share compensator is presented. The effect of this current sharing scheme on 'system output impedance' is analyzed.

Dose finding with the sequential parallel comparison design.

PubMed

Wang, Jessie J; Ivanova, Anastasia

2014-01-01

The sequential parallel comparison design (SPCD) is a two-stage design recommended for trials with possibly high placebo response. A drug-placebo comparison in the first stage is followed in the second stage by placebo nonresponders being re-randomized between drug and placebo. We describe how SPCD can be used in trials where multiple doses of a drug or multiple treatments are compared with placebo and present two adaptive approaches. We detail how to analyze data in such trials and give recommendations about the allocation proportion to placebo in the two stages of SPCD.

Design of a 6-DOF upper limb rehabilitation exoskeleton with parallel actuated joints.

PubMed

Chen, Yanyan; Li, Ge; Zhu, Yanhe; Zhao, Jie; Cai, Hegao

2014-01-01

In this paper, a 6-DOF wearable upper limb exoskeleton with parallel actuated joints which perfectly mimics human motions is proposed. The upper limb exoskeleton assists the movement of physically weak people. Compared with the existing upper limb exoskeletons which are mostly designed using a serial structure with large movement space but small stiffness and poor wearable ability, a prototype for motion assistance based on human anatomy structure has been developed in our design. Moreover, the design adopts balls instead of bearings to save space, which simplifies the structure and reduces the cost of the mechanism. The proposed design also employs deceleration processes to ensure that the transmission ratio of each joint is coincident.

A pivotal registration phase III, multicenter, randomized tuberculosis controlled trial: design issues and lessons learnt from the Gatifloxacin for TB (OFLOTUB) project.

PubMed

Merle, Corinne S C; Sismanidis, Charalambos; Sow, Oumou Bah; Gninafon, Martin; Horton, John; Lapujade, Olivier; Lo, Mame Bocar; Mitchinson, Denis A; Perronne, Christian; Portaels, Francoise; Odhiambo, Joseph; Olliaro, Piero; Rustomjee, Roxana; Lienhardt, Christian; Fielding, Katherine

2012-05-18

There have been no major advances in tuberculosis (TB) drug development since the first East African/British Medical Research Council short course chemotherapy trial 35 years ago. Since then, the landscape for conducting TB clinical trials has profoundly changed with the emergence of HIV infection, the spread of resistant TB bacilli strains, recent advances in mycobacteriological capacity, and drug discovery. As a consequence questions have arisen on the most appropriate approach to design and conduct current TB trials. To highlight key issues discussed: Is a superiority, equivalence, or non-inferiority design most appropriate? What should be the primary efficacy outcome? How to consider re-infections in the definition of the outcome? What is the optimal length of patient follow-up? Is blinding appropriate when treatment duration in test arm is shorter? What are the appropriate assumptions for sample size calculation? Various drugs are currently in the development pipeline. We are presenting in this paper the design of the most recently completed phase III TB trial, the OFLOTUB project, which is the pivotal trial of a registration portfolio for a gatifloxacin-containing TB regimen. It is a randomized, open-label, multicenter, controlled trial aiming to evaluate the efficacy and safety of a gatifloxacin-containing 4-month regimen (trial registration: ClinicalTrial.gov database: NCT00216385). In the light of the recent scientific and regulatory discussions, we discuss some of the design issues in TB clinical trials and more specifically the reasons that guided our choices, in order to best answer the trial objectives, while at the same time satisfying regulatory authority requirements. When shortening TB treatment, we are advocating for a non-inferiority, non-blinded design, with a composite unfavorable endpoint assessed 12 months post treatment completion, and added trial procedures specifically aiming to: (1) minimize endpoint unavailability; and (2) distinguish between relapse and re-infection.

A pivotal registration phase III, multicenter, randomized tuberculosis controlled trial: design issues and lessons learnt from the Gatifloxacin for TB (OFLOTUB) project

PubMed Central

2012-01-01

Background There have been no major advances in tuberculosis (TB) drug development since the first East African/British Medical Research Council short course chemotherapy trial 35 years ago. Since then, the landscape for conducting TB clinical trials has profoundly changed with the emergence of HIV infection, the spread of resistant TB bacilli strains, recent advances in mycobacteriological capacity, and drug discovery. As a consequence questions have arisen on the most appropriate approach to design and conduct current TB trials. To highlight key issues discussed: Is a superiority, equivalence, or non-inferiority design most appropriate? What should be the primary efficacy outcome? How to consider re-infections in the definition of the outcome? What is the optimal length of patient follow-up? Is blinding appropriate when treatment duration in test arm is shorter? What are the appropriate assumptions for sample size calculation? Methods Various drugs are currently in the development pipeline. We are presenting in this paper the design of the most recently completed phase III TB trial, the OFLOTUB project, which is the pivotal trial of a registration portfolio for a gatifloxacin-containing TB regimen. It is a randomized, open-label, multicenter, controlled trial aiming to evaluate the efficacy and safety of a gatifloxacin-containing 4-month regimen (trial registration: ClinicalTrial.gov database: NCT00216385). Results In the light of the recent scientific and regulatory discussions, we discuss some of the design issues in TB clinical trials and more specifically the reasons that guided our choices, in order to best answer the trial objectives, while at the same time satisfying regulatory authority requirements. Conclusion When shortening TB treatment, we are advocating for a non-inferiority, non-blinded design, with a composite unfavorable endpoint assessed 12 months post treatment completion, and added trial procedures specifically aiming to: (1) minimize endpoint unavailability; and (2) distinguish between relapse and re-infection. PMID:22607233

Analysis and Design of ITER 1 MV Core Snubber

NASA Astrophysics Data System (ADS)

Wang, Haitian; Li, Ge

2012-11-01

The core snubber, as a passive protection device, can suppress arc current and absorb stored energy in stray capacitance during the electrical breakdown in accelerating electrodes of ITER NBI. In order to design the core snubber of ITER, the control parameters of the arc peak current have been firstly analyzed by the Fink-Baker-Owren (FBO) method, which are used for designing the DIIID 100 kV snubber. The B-H curve can be derived from the measured voltage and current waveforms, and the hysteresis loss of the core snubber can be derived using the revised parallelogram method. The core snubber can be a simplified representation as an equivalent parallel resistance and inductance, which has been neglected by the FBO method. A simulation code including the parallel equivalent resistance and inductance has been set up. The simulation and experiments result in dramatically large arc shorting currents due to the parallel inductance effect. The case shows that the core snubber utilizing the FBO method gives more compact design.

OpenCL: A Parallel Programming Standard for Heterogeneous Computing Systems

PubMed Central

Stone, John E.; Gohara, David; Shi, Guochun

2010-01-01

We provide an overview of the key architectural features of recent microprocessor designs and describe the programming model and abstractions provided by OpenCL, a new parallel programming standard targeting these architectures. PMID:21037981

DOE Office of Scientific and Technical Information (OSTI.GOV)

Janjusic, Tommy; Kartsaklis, Christos

Memory scalability is an enduring problem and bottleneck that plagues many parallel codes. Parallel codes designed for High Performance Systems are typically designed over the span of several, and in some instances 10+, years. As a result, optimization practices which were appropriate for earlier systems may no longer be valid and thus require careful optimization consideration. Specifically, parallel codes whose memory footprint is a function of their scalability must be carefully considered for future exa-scale systems. In this paper we present a methodology and tool to study the memory scalability of parallel codes. Using our methodology we evaluate an applicationmore » s memory footprint as a function of scalability, which we coined memory efficiency, and describe our results. In particular, using our in-house tools we can pinpoint the specific application components which contribute to the application s overall memory foot-print (application data- structures, libraries, etc.).« less

Epidemiology of Transfusion-Transmitted Infections Among Multi-Transfused Patients in Seven Hospitals in Peru

DTIC Science & Technology

2005-01-01

locate jcv Epidemiology of transfusion-transmitted infections among multi-transfused patients in seven hospitals in Peru 1 VA. Laguna-Torres a...and risk factors associated with TTIs among a sample of multi-transfused adult patients in Peru Study design: A cross- sectional multi-center study...was conducted across seven major hospitals in Peru fi’om February 2003 to September 2004 Self-reported behavior lntbrmatlon (medical procedures

ALHAT: Autonomous Landing and Hazard Avoidance Technology

NASA Technical Reports Server (NTRS)

Robertson, Edward A.; Carson, John M., III

2015-01-01

The ALHAT project was chartered by NASA HQ in 2006 to develop and mature to TRL 6 an autonomous lunar landing GN&C and sensing system for crewed, cargo, and robotic planetary landing vehicles. The multi-center ALHAT team was tasked with providing a system capable of identifying and avoiding surface hazards in real time to enable safe precision landing to within tens of meters of a designated planetary landing site under any lighting conditions.

HIV Risk Reduction Among Young Adult Chronic Psychiatric Patients

DTIC Science & Technology

1990-08-28

was noted in a cohort of gay men in California. The human immunodeficiency virus (HIV) was discovered as the cause of AIDS and the HI V antibody...sexual practices among homosexual and bisexual men provide a framework for the development of any prevention program designed to reduce the risk of HIV...and the Multicenter Aids Cohort Study and note that many gay men have significantly reduced the frequency of unprotected anal Intercourse. Winkelstein

Parallel auto-correlative statistics with VTK.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pebay, Philippe Pierre; Bennett, Janine Camille

2013-08-01

This report summarizes existing statistical engines in VTK and presents both the serial and parallel auto-correlative statistics engines. It is a sequel to [PT08, BPRT09b, PT09, BPT09, PT10] which studied the parallel descriptive, correlative, multi-correlative, principal component analysis, contingency, k-means, and order statistics engines. The ease of use of the new parallel auto-correlative statistics engine is illustrated by the means of C++ code snippets and algorithm verification is provided. This report justifies the design of the statistics engines with parallel scalability in mind, and provides scalability and speed-up analysis results for the autocorrelative statistics engine.

Matching pursuit parallel decomposition of seismic data

NASA Astrophysics Data System (ADS)

Li, Chuanhui; Zhang, Fanchang

2017-07-01

In order to improve the computation speed of matching pursuit decomposition of seismic data, a matching pursuit parallel algorithm is designed in this paper. We pick a fixed number of envelope peaks from the current signal in every iteration according to the number of compute nodes and assign them to the compute nodes on average to search the optimal Morlet wavelets in parallel. With the help of parallel computer systems and Message Passing Interface, the parallel algorithm gives full play to the advantages of parallel computing to significantly improve the computation speed of the matching pursuit decomposition and also has good expandability. Besides, searching only one optimal Morlet wavelet by every compute node in every iteration is the most efficient implementation.

Research on Parallel Three Phase PWM Converters base on RTDS

NASA Astrophysics Data System (ADS)

Xia, Yan; Zou, Jianxiao; Li, Kai; Liu, Jingbo; Tian, Jun

2018-01-01

Converters parallel operation can increase capacity of the system, but it may lead to potential zero-sequence circulating current, so the control of circulating current was an important goal in the design of parallel inverters. In this paper, the Real Time Digital Simulator (RTDS) is used to model the converters parallel system in real time and study the circulating current restraining. The equivalent model of two parallel converters and zero-sequence circulating current(ZSCC) were established and analyzed, then a strategy using variable zero vector control was proposed to suppress the circulating current. For two parallel modular converters, hardware-in-the-loop(HIL) study based on RTDS and practical experiment were implemented, results prove that the proposed control strategy is feasible and effective.

User's Guide for TOUGH2-MP - A Massively Parallel Version of the TOUGH2 Code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Earth Sciences Division; Zhang, Keni; Zhang, Keni

TOUGH2-MP is a massively parallel (MP) version of the TOUGH2 code, designed for computationally efficient parallel simulation of isothermal and nonisothermal flows of multicomponent, multiphase fluids in one, two, and three-dimensional porous and fractured media. In recent years, computational requirements have become increasingly intensive in large or highly nonlinear problems for applications in areas such as radioactive waste disposal, CO2 geological sequestration, environmental assessment and remediation, reservoir engineering, and groundwater hydrology. The primary objective of developing the parallel-simulation capability is to significantly improve the computational performance of the TOUGH2 family of codes. The particular goal for the parallel simulator ismore » to achieve orders-of-magnitude improvement in computational time for models with ever-increasing complexity. TOUGH2-MP is designed to perform parallel simulation on multi-CPU computational platforms. An earlier version of TOUGH2-MP (V1.0) was based on the TOUGH2 Version 1.4 with EOS3, EOS9, and T2R3D modules, a software previously qualified for applications in the Yucca Mountain project, and was designed for execution on CRAY T3E and IBM SP supercomputers. The current version of TOUGH2-MP (V2.0) includes all fluid property modules of the standard version TOUGH2 V2.0. It provides computationally efficient capabilities using supercomputers, Linux clusters, or multi-core PCs, and also offers many user-friendly features. The parallel simulator inherits all process capabilities from V2.0 together with additional capabilities for handling fractured media from V1.4. This report provides a quick starting guide on how to set up and run the TOUGH2-MP program for users with a basic knowledge of running the (standard) version TOUGH2 code, The report also gives a brief technical description of the code, including a discussion of parallel methodology, code structure, as well as mathematical and numerical methods used. To familiarize users with the parallel code, illustrative sample problems are presented.« less

NAT2 genotype guided regimen reduces isoniazid-induced liver injury and early treatment failure in the 6-month four-drug standard treatment of tuberculosis: a randomized controlled trial for pharmacogenetics-based therapy.

PubMed

Azuma, Junichi; Ohno, Masako; Kubota, Ryuji; Yokota, Soichiro; Nagai, Takayuki; Tsuyuguchi, Kazunari; Okuda, Yasuhisa; Takashima, Tetsuya; Kamimura, Sayaka; Fujio, Yasushi; Kawase, Ichiro

2013-05-01

This study is a pharmacogenetic clinical trial designed to clarify whether the N-acetyltransferase 2 gene (NAT2) genotype-guided dosing of isoniazid improves the tolerability and efficacy of the 6-month four-drug standard regimen for newly diagnosed pulmonary tuberculosis. In a multicenter, parallel, randomized, and controlled trial with a PROBE design, patients were assigned to either conventional standard treatment (STD-treatment: approx. 5 mg/kg of isoniazid for all) or NAT2 genotype-guided treatment (PGx-treatment: approx. 7.5 mg/kg for patients homozygous for NAT2 4: rapid acetylators; 5 mg/kg, patients heterozygous for NAT2 4: intermediate acetylators; 2.5 mg/kg, patients without NAT2 4: slow acetylators). The primary outcome included incidences of 1) isoniazid-related liver injury (INH-DILI) during the first 8 weeks of therapy, and 2) early treatment failure as indicated by a persistent positive culture or no improvement in chest radiographs at the 8th week. One hundred and seventy-two Japanese patients (slow acetylators, 9.3 %; rapid acetylators, 53.5 %) were enrolled in this trial. In the intention-to-treat (ITT) analysis, INH-DILI occurred in 78 % of the slow acetylators in the STD-treatment, while none of the slow acetylators in the PGx-treatment experienced either INH-DILI or early treatment failure. Among the rapid acetylators, early treatment failure was observed with a significantly lower incidence rate in the PGx-treatment than in the STD-treatment (15.0 % vs. 38 %). Thus, the NAT2 genotype-guided regimen resulted in much lower incidences of unfavorable events, INH-DILI or early treatment failure, than the conventional standard regimen. Our results clearly indicate a great potential of the NAT2 genotype-guided dosing stratification of isoniazid in chemotherapy for tuberculosis.

Improving psychotropic drug prescription in nursing home patients with dementia: design of a cluster randomized controlled trial

PubMed Central

2013-01-01

Background Neuropsychiatric symptoms are highly prevalent in nursing home patients with dementia. Despite modest effectiveness and considerable side effects, psychotropic drugs are frequently prescribed for these neuropsychiatric symptoms. This raises questions whether psychotropic drugs are appropriately prescribed. The aim of the PROPER (PRescription Optimization of Psychotropic drugs in Elderly nuRsing home patients with dementia) II study is to investigate the efficacy of an intervention for improving the appropriateness of psychotropic drug prescription in nursing home patients with dementia. Methods/design The PROPER II study is a multi-center cluster randomized controlled, pragmatic trial using parallel groups. It has a duration of eighteen months and four six-monthly assessments. Six nursing homes will participate in the intervention and six will continue care as usual. The nursing homes will be located throughout the Netherlands, each participating with two dementia special care units with an average of fifteen patients per unit, resulting in 360 patients. The intervention consists of a structured and repeated multidisciplinary medication review supported by education and continuous evaluation. It is conducted by pharmacists, physicians, and nurses and consists of three components: 1) preparation and education, 2) conduct, and 3) evaluation/guidance. The primary outcome is the proportion of patients with appropriate psychotropic drug use. Secondary outcomes are the overall frequency of psychotropic drug use, neuropsychiatric symptoms, quality of life, activities of daily living, psychotropic drug side effects and adverse events (including cognition, comorbidity, and mortality). Besides, a process analysis on the intervention will be carried out. Discussion This study is expected to improve the appropriateness of psychotropic drug prescription for neuropsychiatric symptoms in nursing home patients with dementia by introducing a structured and repeated multidisciplinary medication review supported by education and continuous evaluation. Trial registration Netherlands Trial Registry (NTR): NTR3569. PMID:24180295

The contrast media and nephrotoxicity following coronary revascularization by primary angioplasty for acute myocardial infarction study: design and rationale of the CONTRAST-AMI study.

PubMed

Bolognese, Leonardo; Falsini, Giovanni; Grotti, Simone; Limbruno, Ugo; Liistro, Francesco; Carrera, Arcangelo; Angioli, Paolo; Picchi, Andrea; Ducci, Kenneth; Pierli, Carlo

2010-03-01

Contrast-induced acute kidney injury (CI-AKI) is a complex syndrome of acute renal failure occurring after the administration of contrast media and contributing to prolonged hospital stay and mortality. The risk of CI-AKI is higher among patients undergoing primary percutaneous coronary interventions for acute myocardial infarction (AMI), but its clinical relevance in such setting has only been evaluated by small sample size single-center studies and retrospective or observational analyses. Furthermore, whereas high-osmolar contrast media was shown to have direct nephrotoxicity, the role of low-osmolar and iso-osmolar agents is still debated. The CONTRAST-AMI study is a prospective, multicenter, controlled, randomized, single-blind, parallel-group trial, designed to show the noninferiority of the effects of iopromide (low-osmolar) compared with iodixanol (iso-osmolar) contrast media on the incidence of CI-AKI and tissue-level perfusion in patients with AMI. All consecutive patients admitted to participating centers for ST-segment elevation AMI undergoing primary percutaneous coronary intervention will be enrolled. All patients will be treated with high-dose N-acetylcysteine (1200 mg intravenously during the procedure and 1200 mg orally two times daily for the next 48 h after percutaneous coronary intervention) and hydration according to a standardized protocol. The primary endpoint is the proportion of patients with a relative increase in serum creatinine (sCr) of at least 25% from baseline to 72 h after agent administration. The secondary endpoints are absolute and relative increases in sCr of at least 50%, thrombolysis in myocardial infarction (TIMI) perfusion grade, and major adverse cardiac events at 1, 6, and 12 months. The CONTRAST-AMI study will provide information on the effects of iodixanol and iopromide on the incidence of CI-AKI and tissue-level perfusion in patients with AMI.

A Metascalable Computing Framework for Large Spatiotemporal-Scale Atomistic Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nomura, K; Seymour, R; Wang, W

2009-02-17

A metascalable (or 'design once, scale on new architectures') parallel computing framework has been developed for large spatiotemporal-scale atomistic simulations of materials based on spatiotemporal data locality principles, which is expected to scale on emerging multipetaflops architectures. The framework consists of: (1) an embedded divide-and-conquer (EDC) algorithmic framework based on spatial locality to design linear-scaling algorithms for high complexity problems; (2) a space-time-ensemble parallel (STEP) approach based on temporal locality to predict long-time dynamics, while introducing multiple parallelization axes; and (3) a tunable hierarchical cellular decomposition (HCD) parallelization framework to map these O(N) algorithms onto a multicore cluster based onmore » hybrid implementation combining message passing and critical section-free multithreading. The EDC-STEP-HCD framework exposes maximal concurrency and data locality, thereby achieving: (1) inter-node parallel efficiency well over 0.95 for 218 billion-atom molecular-dynamics and 1.68 trillion electronic-degrees-of-freedom quantum-mechanical simulations on 212,992 IBM BlueGene/L processors (superscalability); (2) high intra-node, multithreading parallel efficiency (nanoscalability); and (3) nearly perfect time/ensemble parallel efficiency (eon-scalability). The spatiotemporal scale covered by MD simulation on a sustained petaflops computer per day (i.e. petaflops {center_dot} day of computing) is estimated as NT = 2.14 (e.g. N = 2.14 million atoms for T = 1 microseconds).« less

Exploiting Symmetry on Parallel Architectures.

NASA Astrophysics Data System (ADS)

Stiller, Lewis Benjamin

1995-01-01

This thesis describes techniques for the design of parallel programs that solve well-structured problems with inherent symmetry. Part I demonstrates the reduction of such problems to generalized matrix multiplication by a group-equivariant matrix. Fast techniques for this multiplication are described, including factorization, orbit decomposition, and Fourier transforms over finite groups. Our algorithms entail interaction between two symmetry groups: one arising at the software level from the problem's symmetry and the other arising at the hardware level from the processors' communication network. Part II illustrates the applicability of our symmetry -exploitation techniques by presenting a series of case studies of the design and implementation of parallel programs. First, a parallel program that solves chess endgames by factorization of an associated dihedral group-equivariant matrix is described. This code runs faster than previous serial programs, and discovered it a number of results. Second, parallel algorithms for Fourier transforms for finite groups are developed, and preliminary parallel implementations for group transforms of dihedral and of symmetric groups are described. Applications in learning, vision, pattern recognition, and statistics are proposed. Third, parallel implementations solving several computational science problems are described, including the direct n-body problem, convolutions arising from molecular biology, and some communication primitives such as broadcast and reduce. Some of our implementations ran orders of magnitude faster than previous techniques, and were used in the investigation of various physical phenomena.

Big Data: A Parallel Particle Swarm Optimization-Back-Propagation Neural Network Algorithm Based on MapReduce.

PubMed

Cao, Jianfang; Cui, Hongyan; Shi, Hao; Jiao, Lijuan

2016-01-01

A back-propagation (BP) neural network can solve complicated random nonlinear mapping problems; therefore, it can be applied to a wide range of problems. However, as the sample size increases, the time required to train BP neural networks becomes lengthy. Moreover, the classification accuracy decreases as well. To improve the classification accuracy and runtime efficiency of the BP neural network algorithm, we proposed a parallel design and realization method for a particle swarm optimization (PSO)-optimized BP neural network based on MapReduce on the Hadoop platform using both the PSO algorithm and a parallel design. The PSO algorithm was used to optimize the BP neural network's initial weights and thresholds and improve the accuracy of the classification algorithm. The MapReduce parallel programming model was utilized to achieve parallel processing of the BP algorithm, thereby solving the problems of hardware and communication overhead when the BP neural network addresses big data. Datasets on 5 different scales were constructed using the scene image library from the SUN Database. The classification accuracy of the parallel PSO-BP neural network algorithm is approximately 92%, and the system efficiency is approximately 0.85, which presents obvious advantages when processing big data. The algorithm proposed in this study demonstrated both higher classification accuracy and improved time efficiency, which represents a significant improvement obtained from applying parallel processing to an intelligent algorithm on big data.

The Tera Multithreaded Architecture and Unstructured Meshes

NASA Technical Reports Server (NTRS)

Bokhari, Shahid H.; Mavriplis, Dimitri J.

1998-01-01

The Tera Multithreaded Architecture (MTA) is a new parallel supercomputer currently being installed at San Diego Supercomputing Center (SDSC). This machine has an architecture quite different from contemporary parallel machines. The computational processor is a custom design and the machine uses hardware to support very fine grained multithreading. The main memory is shared, hardware randomized and flat. These features make the machine highly suited to the execution of unstructured mesh problems, which are difficult to parallelize on other architectures. We report the results of a study carried out during July-August 1998 to evaluate the execution of EUL3D, a code that solves the Euler equations on an unstructured mesh, on the 2 processor Tera MTA at SDSC. Our investigation shows that parallelization of an unstructured code is extremely easy on the Tera. We were able to get an existing parallel code (designed for a shared memory machine), running on the Tera by changing only the compiler directives. Furthermore, a serial version of this code was compiled to run in parallel on the Tera by judicious use of directives to invoke the "full/empty" tag bits of the machine to obtain synchronization. This version achieves 212 and 406 Mflop/s on one and two processors respectively, and requires no attention to partitioning or placement of data issues that would be of paramount importance in other parallel architectures.

Experimental characterization of a binary actuated parallel manipulator

NASA Astrophysics Data System (ADS)

Giuseppe, Carbone

2016-05-01

This paper describes the BAPAMAN (Binary Actuated Parallel MANipulator) series of parallel manipulators that has been conceived at Laboratory of Robotics and Mechatronics (LARM). Basic common characteristics of BAPAMAN series are described. In particular, it is outlined the use of a reduced number of active degrees of freedom, the use of design solutions with flexural joints and Shape Memory Alloy (SMA) actuators for achieving miniaturization, cost reduction and easy operation features. Given the peculiarities of BAPAMAN architecture, specific experimental tests have been proposed and carried out with the aim to validate the proposed design and to evaluate the practical operation performance and the characteristics of a built prototype, in particular, in terms of operation and workspace characteristics.

Intraocular pressure decrease with preservative-free fixed and unfixed combination of tafluprost and timolol in pseudoexfoliative glaucoma.

PubMed

Holló, Gábor; Ropo, Auli

2015-01-01

We investigated the intraocular pressure (IOP) lowering efficacy of preservative-free fixed and non-fixed combination of tafluprost 0.0015% and timolol 0.5% in pseudoexfoliative glaucoma (XFG). A per protocol worse eye analysis was made on all XFG patients who participated in a recent 6 month, prospective, randomized, double-masked, parallel group, multicenter phase III study. The mean time-wise IOP decreased by 8.62 to 10.25 mmHg (31.8 to 36.7%) in the fixed dose combination arm (15 patients) and by 5.38 to 11.35 mmHg (21.3 to 41.2%) in the non-fixed combination arm (13 patients), respectively (p < 0.001 for all comparisons). The results show that a preservative-free fixed dose combination of tafluprost and timolol provides a clinically significant IOP reduction in XFG, and may offer an advantage for the XFG patients with dry eye, due to its preservative-free nature.

Lack of significant anti-inflammatory activity with clindamycin in the treatment of rosacea: results of 2 randomized, vehicle-controlled trials.

PubMed

Martel, Philippe; Jarratt, Michael; Weiss, Jonathan; Carlavan, Isabelle

2017-07-01

Rosacea is a chronic inflammatory skin disease of the face. The objective of the studies described here was to evaluate the efficacy of clindamycin in the treatment of rosacea. Two multicenter, randomized, vehicle-controlled, phase 2 studies were conducted in participants with moderate to severe rosacea. Study A was a 12-week dose-comparison, 5-arm, parallel group comparison of clindamycin cream 1% or vehicle once or twice daily and clindamycin cream 0.3% once daily. Study B was a 2-arm comparison of twice daily clindamycin gel 1% versus vehicle gel. A total of 629 participants (study A, N=416; study B, N=213) were randomized. The results of these studies indicated that clindamycin cream 0.3% and 1% and clindamycin gel 1% were no more effective than the vehicle in the treatment of moderate to severe rosacea, suggesting clindamycin has no intrinsic anti-inflammatory activity in rosacea.

Deterministic Evolutionary Trajectories Influence Primary Tumor Growth: TRACERx Renal.

PubMed

Turajlic, Samra; Xu, Hang; Litchfield, Kevin; Rowan, Andrew; Horswell, Stuart; Chambers, Tim; O'Brien, Tim; Lopez, Jose I; Watkins, Thomas B K; Nicol, David; Stares, Mark; Challacombe, Ben; Hazell, Steve; Chandra, Ashish; Mitchell, Thomas J; Au, Lewis; Eichler-Jonsson, Claudia; Jabbar, Faiz; Soultati, Aspasia; Chowdhury, Simon; Rudman, Sarah; Lynch, Joanna; Fernando, Archana; Stamp, Gordon; Nye, Emma; Stewart, Aengus; Xing, Wei; Smith, Jonathan C; Escudero, Mickael; Huffman, Adam; Matthews, Nik; Elgar, Greg; Phillimore, Ben; Costa, Marta; Begum, Sharmin; Ward, Sophia; Salm, Max; Boeing, Stefan; Fisher, Rosalie; Spain, Lavinia; Navas, Carolina; Grönroos, Eva; Hobor, Sebastijan; Sharma, Sarkhara; Aurangzeb, Ismaeel; Lall, Sharanpreet; Polson, Alexander; Varia, Mary; Horsfield, Catherine; Fotiadis, Nicos; Pickering, Lisa; Schwarz, Roland F; Silva, Bruno; Herrero, Javier; Luscombe, Nick M; Jamal-Hanjani, Mariam; Rosenthal, Rachel; Birkbak, Nicolai J; Wilson, Gareth A; Pipek, Orsolya; Ribli, Dezso; Krzystanek, Marcin; Csabai, Istvan; Szallasi, Zoltan; Gore, Martin; McGranahan, Nicholas; Van Loo, Peter; Campbell, Peter; Larkin, James; Swanton, Charles

2018-04-19

The evolutionary features of clear-cell renal cell carcinoma (ccRCC) have not been systematically studied to date. We analyzed 1,206 primary tumor regions from 101 patients recruited into the multi-center prospective study, TRACERx Renal. We observe up to 30 driver events per tumor and show that subclonal diversification is associated with known prognostic parameters. By resolving the patterns of driver event ordering, co-occurrence, and mutual exclusivity at clone level, we show the deterministic nature of clonal evolution. ccRCC can be grouped into seven evolutionary subtypes, ranging from tumors characterized by early fixation of multiple mutational and copy number drivers and rapid metastases to highly branched tumors with >10 subclonal drivers and extensive parallel evolution associated with attenuated progression. We identify genetic diversity and chromosomal complexity as determinants of patient outcome. Our insights reconcile the variable clinical behavior of ccRCC and suggest evolutionary potential as a biomarker for both intervention and surveillance. Copyright © 2018 Francis Crick Institute. Published by Elsevier Inc. All rights reserved.

Azilsartan in Patients With Mild to Moderate Hypertension Using Clinic and Ambulatory Blood Pressure Measurements.

PubMed

Perez, Alfonso; Cao, Charlie

2017-01-01

This was a phase 2, multicenter, randomized, parallel-group, double-blind dose-ranging study. Hypertensive adults (n=555) received one of five doses of azilsartan (AZL; 2.5, 5, 10, 20, 40 mg), olmesartan medoxomil (OLM) 20 mg, or placebo once daily. The primary endpoint was change in trough clinic diastolic blood pressure (DBP) at week 8. Compared with placebo, all AZL doses (except 2.5 mg) provided statistically and clinically significant reductions in DBP and systolic blood pressure (SBP) based on both clinic blood pressure (BP) and 24-hour ambulatory BP monitoring (ABPM). AZL 40 mg was statistically superior vs OLM. Clinic BP was associated with a pronounced placebo effect (-6 mm Hg), whereas this was negligible with ABPM (±0.5 mm Hg). Adverse event frequency was similar in the AZL and placebo groups. Based on these and other findings, subsequent trials investigated the commercial AZL medoxomil tablet at doses 20 to 80 mg/d using 24-hour ABPM. ©2016 Wiley Periodicals, Inc.

File-access characteristics of parallel scientific workloads

NASA Technical Reports Server (NTRS)

Nieuwejaar, Nils; Kotz, David; Purakayastha, Apratim; Best, Michael; Ellis, Carla Schlatter

1995-01-01

Phenomenal improvements in the computational performance of multiprocessors have not been matched by comparable gains in I/O system performance. This imbalance has resulted in I/O becoming a significant bottleneck for many scientific applications. One key to overcoming this bottleneck is improving the performance of parallel file systems. The design of a high-performance parallel file system requires a comprehensive understanding of the expected workload. Unfortunately, until recently, no general workload studies of parallel file systems have been conducted. The goal of the CHARISMA project was to remedy this problem by characterizing the behavior of several production workloads, on different machines, at the level of individual reads and writes. The first set of results from the CHARISMA project describe the workloads observed on an Intel iPSC/860 and a Thinking Machines CM-5. This paper is intended to compare and contrast these two workloads for an understanding of their essential similarities and differences, isolating common trends and platform-dependent variances. Using this comparison, we are able to gain more insight into the general principles that should guide parallel file-system design.

A Novel Design of 4-Class BCI Using Two Binary Classifiers and Parallel Mental Tasks

PubMed Central

Geng, Tao; Gan, John Q.; Dyson, Matthew; Tsui, Chun SL; Sepulveda, Francisco

2008-01-01

A novel 4-class single-trial brain computer interface (BCI) based on two (rather than four or more) binary linear discriminant analysis (LDA) classifiers is proposed, which is called a “parallel BCI.” Unlike other BCIs where mental tasks are executed and classified in a serial way one after another, the parallel BCI uses properly designed parallel mental tasks that are executed on both sides of the subject body simultaneously, which is the main novelty of the BCI paradigm used in our experiments. Each of the two binary classifiers only classifies the mental tasks executed on one side of the subject body, and the results of the two binary classifiers are combined to give the result of the 4-class BCI. Data was recorded in experiments with both real movement and motor imagery in 3 able-bodied subjects. Artifacts were not detected or removed. Offline analysis has shown that, in some subjects, the parallel BCI can generate a higher accuracy than a conventional 4-class BCI, although both of them have used the same feature selection and classification algorithms. PMID:18584040

The BLAZE language: A parallel language for scientific programming

NASA Technical Reports Server (NTRS)

Mehrotra, P.; Vanrosendale, J.

1985-01-01

A Pascal-like scientific programming language, Blaze, is described. Blaze contains array arithmetic, forall loops, and APL-style accumulation operators, which allow natural expression of fine grained parallelism. It also employs an applicative or functional procedure invocation mechanism, which makes it easy for compilers to extract coarse grained parallelism using machine specific program restructuring. Thus Blaze should allow one to achieve highly parallel execution on multiprocessor architectures, while still providing the user with onceptually sequential control flow. A central goal in the design of Blaze is portability across a broad range of parallel architectures. The multiple levels of parallelism present in Blaze code, in principle, allow a compiler to extract the types of parallelism appropriate for the given architecture while neglecting the remainder. The features of Blaze are described and shows how this language would be used in typical scientific programming.

A scalable parallel black oil simulator on distributed memory parallel computers

NASA Astrophysics Data System (ADS)

Wang, Kun; Liu, Hui; Chen, Zhangxin

2015-11-01

This paper presents our work on developing a parallel black oil simulator for distributed memory computers based on our in-house parallel platform. The parallel simulator is designed to overcome the performance issues of common simulators that are implemented for personal computers and workstations. The finite difference method is applied to discretize the black oil model. In addition, some advanced techniques are employed to strengthen the robustness and parallel scalability of the simulator, including an inexact Newton method, matrix decoupling methods, and algebraic multigrid methods. A new multi-stage preconditioner is proposed to accelerate the solution of linear systems from the Newton methods. Numerical experiments show that our simulator is scalable and efficient, and is capable of simulating extremely large-scale black oil problems with tens of millions of grid blocks using thousands of MPI processes on parallel computers.

Photonic content-addressable memory system that uses a parallel-readout optical disk

NASA Astrophysics Data System (ADS)

Krishnamoorthy, Ashok V.; Marchand, Philippe J.; Yayla, Gökçe; Esener, Sadik C.

1995-11-01

We describe a high-performance associative-memory system that can be implemented by means of an optical disk modified for parallel readout and a custom-designed silicon integrated circuit with parallel optical input. The system can achieve associative recall on 128 \\times 128 bit images and also on variable-size subimages. The system's behavior and performance are evaluated on the basis of experimental results on a motionless-head parallel-readout optical-disk system, logic simulations of the very-large-scale integrated chip, and a software emulation of the overall system.

RAMA: A file system for massively parallel computers

NASA Technical Reports Server (NTRS)

Miller, Ethan L.; Katz, Randy H.

1993-01-01

This paper describes a file system design for massively parallel computers which makes very efficient use of a few disks per processor. This overcomes the traditional I/O bottleneck of massively parallel machines by storing the data on disks within the high-speed interconnection network. In addition, the file system, called RAMA, requires little inter-node synchronization, removing another common bottleneck in parallel processor file systems. Support for a large tertiary storage system can easily be integrated in lo the file system; in fact, RAMA runs most efficiently when tertiary storage is used.

A Parallel Implementation of Multilevel Recursive Spectral Bisection for Application to Adaptive Unstructured Meshes. Chapter 1

NASA Technical Reports Server (NTRS)

Barnard, Stephen T.; Simon, Horst; Lasinski, T. A. (Technical Monitor)

1994-01-01

The design of a parallel implementation of multilevel recursive spectral bisection is described. The goal is to implement a code that is fast enough to enable dynamic repartitioning of adaptive meshes.

100 Gbps Wireless System and Circuit Design Using Parallel Spread-Spectrum Sequencing

NASA Astrophysics Data System (ADS)

Scheytt, J. Christoph; Javed, Abdul Rehman; Bammidi, Eswara Rao; KrishneGowda, Karthik; Kallfass, Ingmar; Kraemer, Rolf

2017-09-01

In this article mixed analog/digital signal processing techniques based on parallel spread-spectrum sequencing (PSSS) and radio frequency (RF) carrier synchronization for ultra-broadband wireless communication are investigated on system and circuit level.

RTNN: The New Parallel Machine in Zaragoza

NASA Astrophysics Data System (ADS)

Sijs, A. J. V. D.

I report on the development of RTNN, a parallel computer designed as a 4^4 hypercube of 256 T9000 transputer nodes, each with 8 MB memory. The peak performance of the machine is expected to be 2.5 Gflops.

Parallel Hybrid Gas-Electric Geared Turbofan Engine Conceptual Design and Benefits Analysis

NASA Technical Reports Server (NTRS)

Lents, Charles; Hardin, Larry; Rheaume, Jonathan; Kohlman, Lee

2016-01-01

The conceptual design of a parallel gas-electric hybrid propulsion system for a conventional single aisle twin engine tube and wing vehicle has been developed. The study baseline vehicle and engine technology are discussed, followed by results of the hybrid propulsion system sizing and performance analysis. The weights analysis for the electric energy storage & conversion system and thermal management system is described. Finally, the potential system benefits are assessed.

Multivariable speed synchronisation for a parallel hybrid electric vehicle drivetrain

NASA Astrophysics Data System (ADS)

Alt, B.; Antritter, F.; Svaricek, F.; Schultalbers, M.

2013-03-01

In this article, a new drivetrain configuration of a parallel hybrid electric vehicle is considered and a novel model-based control design strategy is given. In particular, the control design covers the speed synchronisation task during a restart of the internal combustion engine. The proposed multivariable synchronisation strategy is based on feedforward and decoupled feedback controllers. The performance and the robustness properties of the closed-loop system are illustrated by nonlinear simulation results.

Automatic differentiation for design sensitivity analysis of structural systems using multiple processors

NASA Technical Reports Server (NTRS)

Nguyen, Duc T.; Storaasli, Olaf O.; Qin, Jiangning; Qamar, Ramzi

1994-01-01

An automatic differentiation tool (ADIFOR) is incorporated into a finite element based structural analysis program for shape and non-shape design sensitivity analysis of structural systems. The entire analysis and sensitivity procedures are parallelized and vectorized for high performance computation. Small scale examples to verify the accuracy of the proposed program and a medium scale example to demonstrate the parallel vector performance on multiple CRAY C90 processors are included.

A method for real-time implementation of HOG feature extraction

NASA Astrophysics Data System (ADS)

Luo, Hai-bo; Yu, Xin-rong; Liu, Hong-mei; Ding, Qing-hai

2011-08-01

Histogram of oriented gradient (HOG) is an efficient feature extraction scheme, and HOG descriptors are feature descriptors which is widely used in computer vision and image processing for the purpose of biometrics, target tracking, automatic target detection(ATD) and automatic target recognition(ATR) etc. However, computation of HOG feature extraction is unsuitable for hardware implementation since it includes complicated operations. In this paper, the optimal design method and theory frame for real-time HOG feature extraction based on FPGA were proposed. The main principle is as follows: firstly, the parallel gradient computing unit circuit based on parallel pipeline structure was designed. Secondly, the calculation of arctangent and square root operation was simplified. Finally, a histogram generator based on parallel pipeline structure was designed to calculate the histogram of each sub-region. Experimental results showed that the HOG extraction can be implemented in a pixel period by these computing units.

Computational mechanics analysis tools for parallel-vector supercomputers

NASA Technical Reports Server (NTRS)

Storaasli, Olaf O.; Nguyen, Duc T.; Baddourah, Majdi; Qin, Jiangning

1993-01-01

Computational algorithms for structural analysis on parallel-vector supercomputers are reviewed. These parallel algorithms, developed by the authors, are for the assembly of structural equations, 'out-of-core' strategies for linear equation solution, massively distributed-memory equation solution, unsymmetric equation solution, general eigensolution, geometrically nonlinear finite element analysis, design sensitivity analysis for structural dynamics, optimization search analysis and domain decomposition. The source code for many of these algorithms is available.

Rationale and design of the German-Speaking Myeloma Multicenter Group (GMMG) trial ReLApsE: a randomized, open, multicenter phase III trial of lenalidomide/dexamethasone versus lenalidomide/dexamethasone plus subsequent autologous stem cell transplantation and lenalidomide maintenance in patients with relapsed multiple myeloma.

PubMed

Baertsch, Marc-Andrea; Schlenzka, Jana; Mai, Elias K; Merz, Maximilian; Hillengaß, Jens; Raab, Marc S; Hose, Dirk; Wuchter, Patrick; Ho, Anthony D; Jauch, Anna; Hielscher, Thomas; Kunz, Christina; Luntz, Steffen; Klein, Stefan; Schmidt-Wolf, Ingo G H; Goerner, Martin; Schmidt-Hieber, Martin; Reimer, Peter; Graeven, Ullrich; Fenk, Roland; Salwender, Hans; Scheid, Christof; Nogai, Axel; Haenel, Mathias; Lindemann, Hans W; Martin, Hans; Noppeney, Richard; Weisel, Katja; Goldschmidt, Hartmut

2016-04-25

Despite novel therapeutic agents, most multiple myeloma (MM) patients eventually relapse. Two large phase III trials have shown significantly improved response rates (RR) of lenalidomide/dexamethasone compared with placebo/dexamethasone in relapsed MM (RMM) patients. These results have led to the approval of lenalidomide for RMM patients and lenalidomide/dexamethasone has since become a widely accepted second-line treatment. Furthermore, in RMM patients consolidation with high-dose chemotherapy plus autologous stem cell transplantation has been shown to significantly increase progression free survival (PFS) as compared to cyclophosphamide in a phase III trial. The randomized prospective ReLApsE trial is designed to evaluate PFS after lenalidomide/dexamethasone induction, high-dose chemotherapy consolidation plus autologous stem cell transplantation and lenalidomide maintenance compared with the well-established lenalidomide/dexamethasone regimen in RMM patients. ReLApsE is a randomized, open, multicenter phase III trial in a planned study population of 282 RMM patients. All patients receive three lenalidomide/dexamethasone cycles and--in absence of available stem cells from earlier harvesting--undergo peripheral blood stem cell mobilization and harvesting. Subsequently, patients in arm A continue on consecutive lenalidomide/dexamethasone cycles, patients in arm B undergo high dose chemotherapy plus autologous stem cell transplantation followed by lenalidomide maintenance until discontinuation criteria are met. Therapeutic response is evaluated after the 3(rd) (arm A + B) and the 5(th) lenalidomide/dexamethasone cycle (arm A) or 2 months after autologous stem cell transplantation (arm B) and every 3 months thereafter (arm A + B). After finishing the study treatment, patients are followed up for survival and subsequent myeloma therapies. The expected trial duration is 6.25 years from first patient in to last patient out. The primary endpoint is PFS, secondary endpoints include overall survival (OS), RR, time to best response and the influence of early versus late salvage high dose chemotherapy plus autologous stem cell transplantation on OS. This phase III trial is designed to evaluate whether high dose chemotherapy plus autologous stem cell transplantation and lenalidomide maintenance after lenalidomide/dexamethasone induction improves PFS compared with the well-established continued lenalidomide/dexamethasone regimen in RMM patients. ISRCTN16345835 (date of registration 2010-08-24).

14 CFR 25.393 - Loads parallel to hinge line.

Code of Federal Regulations, 2010 CFR

2010-01-01

... designed for inertia loads acting parallel to the hinge line. (b) In the absence of more rational data, the inertia loads may be assumed to be equal to KW, where— (1) K=24 for vertical surfaces; (2) K=12 for...

14 CFR 25.393 - Loads parallel to hinge line.

Code of Federal Regulations, 2012 CFR

2012-01-01

... designed for inertia loads acting parallel to the hinge line. (b) In the absence of more rational data, the inertia loads may be assumed to be equal to KW, where— (1) K=24 for vertical surfaces; (2) K=12 for...

14 CFR 25.393 - Loads parallel to hinge line.

Code of Federal Regulations, 2011 CFR

2011-01-01

... designed for inertia loads acting parallel to the hinge line. (b) In the absence of more rational data, the inertia loads may be assumed to be equal to KW, where— (1) K=24 for vertical surfaces; (2) K=12 for...

14 CFR 25.393 - Loads parallel to hinge line.

Code of Federal Regulations, 2014 CFR

2014-01-01

... designed for inertia loads acting parallel to the hinge line. (b) In the absence of more rational data, the inertia loads may be assumed to be equal to KW, where— (1) K=24 for vertical surfaces; (2) K=12 for...

14 CFR 25.393 - Loads parallel to hinge line.

Code of Federal Regulations, 2013 CFR

2013-01-01

... designed for inertia loads acting parallel to the hinge line. (b) In the absence of more rational data, the inertia loads may be assumed to be equal to KW, where— (1) K=24 for vertical surfaces; (2) K=12 for...

Incidence and Outcomes of Cardiopulmonary Resuscitation in Pediatric Intensive Care Units

PubMed Central

Berg, Robert A.; Nadkarni, Vinay M.; Clark, Amy E.; Moler, Frank; Meert, Kathleen; Harrison, Rick E.; Newth, Christopher J. L.; Sutton, Robert M.; Wessel, David L.; Berger, John T.; Carcillo, Joseph; Dalton, Heidi; Heidemann, Sabrina; Shanley, Thomas P.; Zuppa, Athena F.; Doctor, Allan; Tamburro, Robert F.; Jenkins, Tammara L.; Dean, J. Michael; Holubkov, Richard; Pollack, Murray M.

2015-01-01

Objective To determine the incidence of cardiopulmonary resuscitation (CPR) in pediatric intensive care units (PICU) and subsequent outcomes. Design, Setting, and Patients Multi-center prospective observational study of children 30 minutes, p30 minutes of CPR. Conclusions These data establish that contemporary PICU CPR, including long durations of CPR, results in high rates of survival to hospital discharge (45%) and favorable neurologic outcomes among survivors (89%). Rates of survival with favorable neurologic outcomes were similar among cardiac and non-cardiac patients. The rigorous prospective, observational study design avoided the limitations of missing data and potential selection biases inherent in registry and administrative data. PMID:26646466

Study design and rationale of "Synergistic Effect of Combination Therapy with Cilostazol and ProbUcol on Plaque Stabilization and Lesion REgression (SECURE)" study: a double-blind randomised controlled multicenter clinical trial

PubMed Central

2011-01-01

Background Probucol, a cholesterol-lowering agent that paradoxically also lowers high-density lipoprotein cholesterol has been shown to prevent progression of atherosclerosis. The antiplatelet agent cilostazol, which has diverse antiatherogenic properties, has also been shown to reduce restenosis in previous clinical trials. Recent experimental studies have suggested potential synergy between probucol and cilostazol in preventing atherosclerosis, possibly by suppressing inflammatory reactions and promoting cholesterol efflux. Methods/design The Synergistic Effect of combination therapy with Cilostazol and probUcol on plaque stabilization and lesion REgression (SECURE) study is designed as a double-blind, randomised, controlled, multicenter clinical trial to investigate the effect of cilostazol and probucol combination therapy on plaque volume and composition in comparison with cilostazol monotherapy using intravascular ultrasound and Virtual Histology. The primary end point is the change in the plaque volume of index intermediate lesions between baseline and 9-month follow-up. Secondary endpoints include change in plaque composition, neointimal growth after implantation of stents at percutaneous coronary intervention target lesions, and serum levels of lipid components and biomarkers related to atherosclerosis and inflammation. A total of 118 patients will be included in the study. Discussion The SECURE study will deliver important information on the effects of combination therapy on lipid composition and biomarkers related to atherosclerosis, thereby providing insight into the mechanisms underlying the prevention of atherosclerosis progression by cilostazol and probucol. Trial registration number ClinicalTrials (NCT): NCT01031667 PMID:21226953

A comparison of laser-welded titanium and conventional cast frameworks supported by implants in the partially edentulous jaw: a 3-year prospective multicenter study.

PubMed

Jemt, T; Henry, P; Lindén, B; Naert, I; Weber, H; Bergström, C

2000-01-01

The purpose of this prospective multicenter study was to evaluate and compare the clinical performance of laser-welded titanium fixed partial implant-supported prostheses with conventional cast frameworks. Forty-two partially edentulous patients were provided with Brånemark system implants and arranged into 2 groups. Group A was provided with a conventional cast framework with porcelain veneers in one side of the jaw and a laser-welded titanium framework with low-fusing porcelain on the other side. The patients in group B had an old implant prosthesis replaced by a titanium framework prosthesis. The patients were followed for 3 years after prosthesis placement. Clinical and radiographic data were collected and analyzed. Only one implant was lost, and all prostheses were still in function after 3 years. The 2 framework designs showed similar clinical performance with few clinical complications. Only one abutment screw (1%) and 9 porcelain tooth units (5%) fractured. Four prostheses experienced loose gold screws (6%). In group A, marginal bone loss was similar for both designs of prostheses, with a mean of 1.0 mm and 0.3 mm in the maxilla and mandible, respectively. No bone loss was observed on average in group B. No significant relationship (P > 0.05) was observed between marginal bone loss and placement of prosthesis margin or prosthesis design. The use of laser-welded titanium frameworks seems to present similar clinical performance to conventional cast frameworks in partial implant situations after 3 years.

AdiosStMan: Parallelizing Casacore Table Data System using Adaptive IO System

NASA Astrophysics Data System (ADS)

Wang, R.; Harris, C.; Wicenec, A.

2016-07-01

In this paper, we investigate the Casacore Table Data System (CTDS) used in the casacore and CASA libraries, and methods to parallelize it. CTDS provides a storage manager plugin mechanism for third-party developers to design and implement their own CTDS storage managers. Having this in mind, we looked into various storage backend techniques that can possibly enable parallel I/O for CTDS by implementing new storage managers. After carrying on benchmarks showing the excellent parallel I/O throughput of the Adaptive IO System (ADIOS), we implemented an ADIOS based parallel CTDS storage manager. We then applied the CASA MSTransform frequency split task to verify the ADIOS Storage Manager. We also ran a series of performance tests to examine the I/O throughput in a massively parallel scenario.

Broadcasting collective operation contributions throughout a parallel computer

DOEpatents

Faraj, Ahmad [Rochester, MN

2012-02-21

Methods, systems, and products are disclosed for broadcasting collective operation contributions throughout a parallel computer. The parallel computer includes a plurality of compute nodes connected together through a data communications network. Each compute node has a plurality of processors for use in collective parallel operations on the parallel computer. Broadcasting collective operation contributions throughout a parallel computer according to embodiments of the present invention includes: transmitting, by each processor on each compute node, that processor's collective operation contribution to the other processors on that compute node using intra-node communications; and transmitting on a designated network link, by each processor on each compute node according to a serial processor transmission sequence, that processor's collective operation contribution to the other processors on the other compute nodes using inter-node communications.

Parallel design patterns for a low-power, software-defined compressed video encoder

NASA Astrophysics Data System (ADS)

Bruns, Michael W.; Hunt, Martin A.; Prasad, Durga; Gunupudi, Nageswara R.; Sonachalam, Sekar

2011-06-01

Video compression algorithms such as H.264 offer much potential for parallel processing that is not always exploited by the technology of a particular implementation. Consumer mobile encoding devices often achieve real-time performance and low power consumption through parallel processing in Application Specific Integrated Circuit (ASIC) technology, but many other applications require a software-defined encoder. High quality compression features needed for some applications such as 10-bit sample depth or 4:2:2 chroma format often go beyond the capability of a typical consumer electronics device. An application may also need to efficiently combine compression with other functions such as noise reduction, image stabilization, real time clocks, GPS data, mission/ESD/user data or software-defined radio in a low power, field upgradable implementation. Low power, software-defined encoders may be implemented using a massively parallel memory-network processor array with 100 or more cores and distributed memory. The large number of processor elements allow the silicon device to operate more efficiently than conventional DSP or CPU technology. A dataflow programming methodology may be used to express all of the encoding processes including motion compensation, transform and quantization, and entropy coding. This is a declarative programming model in which the parallelism of the compression algorithm is expressed as a hierarchical graph of tasks with message communication. Data parallel and task parallel design patterns are supported without the need for explicit global synchronization control. An example is described of an H.264 encoder developed for a commercially available, massively parallel memorynetwork processor device.

Effectiveness and cost-effectiveness of a guided Internet- and mobile-based intervention for the indicated prevention of major depression in patients with chronic back pain-study protocol of the PROD-BP multicenter pragmatic RCT.

PubMed

Sander, L; Paganini, S; Lin, J; Schlicker, S; Ebert, D D; Buntrock, C; Baumeister, H

2017-01-21

Reducing the disease burden of major depressive disorder (MDD) is of major public health relevance. The prevention of depression is regarded as one possible approach to reach this goal. People with multiple risk factors for MDD such as chronic back pain and subthreshold depressive symptoms may benefit most from preventive measures. The Internet as intervention setting allows for scaling up preventive interventions on a public mental health level. This study is a multicenter pragmatic randomized controlled trial (RCT) of parallel design aiming to investigate the (cost-) effectiveness of an Internet- and mobile-based intervention (IMI) for the prevention of depression in chronic back pain patients (PROD-BP) with subthreshold depressive symptoms. eSano BackCare-DP is a guided, chronic back pain-specific depression prevention intervention based on cognitive behavioral therapy (CBT) principles comprising six weekly plus three optional modules and two booster sessions after completion of the intervention. Trained psychologists provide guidance by sending feedback messages after each module. A total of 406 patients with chronic back pain and without a depressive disorder at baseline will be recruited following orthopedic rehabilitation care and allocated to either intervention or treatment-as-usual (TAU). Primary patient-relevant endpoint of the trial is the time to onset of MDD measured by the telephone-administered Structured Clinical Interview for DSM (SCID) at baseline and 1-year post-randomization. Key secondary outcomes are health-related quality of life, depression severity, pain intensity, pain-related disability, ability to work, intervention satisfaction and adherence as well as side effects of the intervention. Online assessments take place at baseline and 9 weeks as well as 6 and 12 months post-randomization. Cox regression survival analysis will be conducted to estimate hazard ratio at 12-month follow-up. Moreover, an economic analysis will be conducted from a societal and public health perspective. This is the first study examining an IMI for depression prevention in a sample of chronic pain patients. If this implementation of a depression prevention IMI into orthopedic aftercare proves effective, the intervention could be integrated into routine care with minimal costs and extended for use with other chronic diseases. Results will have implications for researchers, health care providers and public health policy makers. The trial is registered at the WHO International Clinical Trials Registry Platform via the German Clinical Studies Trial Register (DRKS): DRKS00007960 . Registered 12 August 2015.

Study protocol of the Diabetes and Depression Study (DAD): a multi-center randomized controlled trial to compare the efficacy of a diabetes-specific cognitive behavioral group therapy versus sertraline in patients with major depression and poorly controlled diabetes mellitus

PubMed Central

2013-01-01

Background Depression is common in diabetes and associated with hyperglycemia, diabetes related complications and mortality. No single intervention has been identified that consistently leads to simultaneous improvement of depression and glycemic control. Our aim is to analyze the efficacy of a diabetes-specific cognitive behavioral group therapy (CBT) compared to sertraline (SER) in adults with depression and poorly controlled diabetes. Methods/Design This study is a multi-center parallel arm randomized controlled trial currently in its data analysis phase. We included 251 patients in 70 secondary care centers across Germany. Key inclusion criteria were: type 1 or 2 diabetes, major depression (diagnosed with the Structured Clinical Interview for DSM-IV, SCID) and hemoglobin A1C >7.5% despite current insulin therapy. During the initial phase, patients received either 50–200 mg/d sertraline or 10 CBT sessions aiming at the remission of depression and enhanced adherence to diabetes treatment and coping with diabetes. Both groups received diabetes treatment as usual. After 12 weeks of this initial open-label therapy, only the treatment-responders (50% depression symptoms reduction, Hamilton Depression Rating Scale, 17-item version [HAMD]) were included in the subsequent one year study phase and represented the primary analysis population. CBT-responders received no further treatment, while SER-responders obtained a continuous, flexible-dose SER regimen as relapse prevention. Adherence to treatment was analyzed using therapeutic drug monitoring (measurement of sertraline and N-desmethylsertraline concentrations in blood serum) and by counting the numbers of CBT sessions received. Outcome assessments were conducted by trained psychologists blinded to group assignment. Group differences in HbA1c (primary outcome) and depression (HAMD, secondary outcome) between 1-year follow-up and baseline will be analyzed by ANCOVA controlling for baseline values. As primary hypothesis we expect that CBT leads to significantly greater improvement of glycemic control in the one year follow-up in treatment responders of the short term phase. Discussion The DAD study is the first randomized controlled trial comparing antidepressants to a psychological treatment in diabetes patients with depression. The study is investigator initiated and was supported by the ‘Förderprogramm Klinische Studien (Clinical Trials)’ and the ‘Competence Network for Diabetes mellitus’ funded by the Federal Ministry of Education and Research (FKZ 01KG0505). Trial registration Current controlled trials ISRCTN89333241. PMID:23915015

Cognitive consequences of early versus late antiepileptic drug withdrawal after pediatric epilepsy surgery, the TimeToStop (TTS) trial: study protocol for a randomized controlled trial.

PubMed

Boshuisen, Kim; Lamberink, Herm J; van Schooneveld, Monique Mj; Cross, J Helen; Arzimanoglou, Alexis; van der Tweel, Ingeborg; Geleijns, Karin; Uiterwaal, Cuno Spm; Braun, Kees Pj

2015-10-26

The goals of intentional curative pediatric epilepsy surgery are to achieve seizure-freedom and antiepileptic drug (AED) freedom. Retrospective cohort studies have indicated that early postoperative AED withdrawal unmasks incomplete surgical success and AED dependency sooner, but not at the cost of long-term seizure outcome. Moreover, AED withdrawal seemed to improve cognitive outcome. A randomized trial is needed to confirm these findings. We hypothesized that early AED withdrawal in children is not only safe, but also beneficial with respect to cognitive functioning. This is a multi-center pragmatic randomized clinical trial to investigate whether early AED withdrawal improves cognitive function, in terms of attention, executive function and intelligence, quality of life and behavior, and to confirm safety in terms of eventual seizure freedom, seizure recurrences and "seizure and AED freedom." Patients will be randomly allocated in parallel groups (1:1) to either early or late AED withdrawal. Randomization will be concealed and stratified for preoperative IQ and medical center. In the early withdrawal arm reduction of AEDs will start 4 months after surgery, while in the late withdrawal arm reduction starts 12 months after surgery, with intended complete cessation of drugs after 12 and 20 months respectively. Cognitive outcome measurements will be performed preoperatively, and at 1 and 2 years following surgery, and consist of assessment of attention and executive functioning using the EpiTrack Junior test and intelligence expressed as IQ (Wechsler Intelligence Scales). Seizure outcomes will be assessed at 24 months after surgery, and at 20 months following start of AED reduction. We aim to randomize 180 patients who underwent anticipated curative epilepsy surgery below 16 years of age, were able to perform the EpiTrack Junior test preoperatively, and have no predictors of poor postoperative seizure prognosis (multifocal magnetic resonance imaging (MRI) abnormalities, incomplete resection of the lesion, epileptic postoperative electroencephalogram (EEG) abnormalities, or more than three AEDs at the time of surgery). Growing experience with epilepsy surgery has changed the view towards postoperative medication policy. In a European collaboration, we designed a multi-center pragmatic randomized clinical trial comparing early with late AED withdrawal to investigate benefits and safety of early AED withdrawal. The TTS trial is supported by the Dutch Epilepsy Fund (NL 08-10) ISRCTN88423240/ 08/05/2013.

Parallel language constructs for tensor product computations on loosely coupled architectures

NASA Technical Reports Server (NTRS)

Mehrotra, Piyush; Vanrosendale, John

1989-01-01

Distributed memory architectures offer high levels of performance and flexibility, but have proven awkard to program. Current languages for nonshared memory architectures provide a relatively low level programming environment, and are poorly suited to modular programming, and to the construction of libraries. A set of language primitives designed to allow the specification of parallel numerical algorithms at a higher level is described. Tensor product array computations are focused on along with a simple but important class of numerical algorithms. The problem of programming 1-D kernal routines is focused on first, such as parallel tridiagonal solvers, and then how such parallel kernels can be combined to form parallel tensor product algorithms is examined.

An object-oriented approach to nested data parallelism

NASA Technical Reports Server (NTRS)

Sheffler, Thomas J.; Chatterjee, Siddhartha

1994-01-01

This paper describes an implementation technique for integrating nested data parallelism into an object-oriented language. Data-parallel programming employs sets of data called 'collections' and expresses parallelism as operations performed over the elements of a collection. When the elements of a collection are also collections, then there is the possibility for 'nested data parallelism.' Few current programming languages support nested data parallelism however. In an object-oriented framework, a collection is a single object. Its type defines the parallel operations that may be applied to it. Our goal is to design and build an object-oriented data-parallel programming environment supporting nested data parallelism. Our initial approach is built upon three fundamental additions to C++. We add new parallel base types by implementing them as classes, and add a new parallel collection type called a 'vector' that is implemented as a template. Only one new language feature is introduced: the 'foreach' construct, which is the basis for exploiting elementwise parallelism over collections. The strength of the method lies in the compilation strategy, which translates nested data-parallel C++ into ordinary C++. Extracting the potential parallelism in nested 'foreach' constructs is called 'flattening' nested parallelism. We show how to flatten 'foreach' constructs using a simple program transformation. Our prototype system produces vector code which has been successfully run on workstations, a CM-2, and a CM-5.

A fast pulse design for parallel excitation with gridding conjugate gradient.

PubMed

Feng, Shuo; Ji, Jim

2013-01-01

Parallel excitation (pTx) is recognized as a crucial technique in high field MRI to address the transmit field inhomogeneity problem. However, it can be time consuming to design pTx pulses which is not desirable. In this work, we propose a pulse design with gridding conjugate gradient (CG) based on the small-tip-angle approximation. The two major time consuming matrix-vector multiplications are substituted by two operators which involves with FFT and gridding only. Simulation results have shown that the proposed method is 3 times faster than conventional method and the memory cost is reduced by 1000 times.

Modeling and Dynamic Analysis of Paralleled of dc/dc Converters with Master-Slave Current Sharing Control

NASA Technical Reports Server (NTRS)

Rajagopalan, J.; Xing, K.; Guo, Y.; Lee, F. C.; Manners, Bruce

1996-01-01

A simple, application-oriented, transfer function model of paralleled converters employing Master-Slave Current-sharing (MSC) control is developed. Dynamically, the Master converter retains its original design characteristics; all the Slave converters are forced to depart significantly from their original design characteristics into current-controlled current sources. Five distinct loop gains to assess system stability and performance are identified and their physical significance is described. A design methodology for the current share compensator is presented. The effect of this current sharing scheme on 'system output impedance' is analyzed.

Parallel rendering

NASA Technical Reports Server (NTRS)

Crockett, Thomas W.

1995-01-01

This article provides a broad introduction to the subject of parallel rendering, encompassing both hardware and software systems. The focus is on the underlying concepts and the issues which arise in the design of parallel rendering algorithms and systems. We examine the different types of parallelism and how they can be applied in rendering applications. Concepts from parallel computing, such as data decomposition, task granularity, scalability, and load balancing, are considered in relation to the rendering problem. We also explore concepts from computer graphics, such as coherence and projection, which have a significant impact on the structure of parallel rendering algorithms. Our survey covers a number of practical considerations as well, including the choice of architectural platform, communication and memory requirements, and the problem of image assembly and display. We illustrate the discussion with numerous examples from the parallel rendering literature, representing most of the principal rendering methods currently used in computer graphics.

The BLAZE language - A parallel language for scientific programming

NASA Technical Reports Server (NTRS)

Mehrotra, Piyush; Van Rosendale, John

1987-01-01

A Pascal-like scientific programming language, BLAZE, is described. BLAZE contains array arithmetic, forall loops, and APL-style accumulation operators, which allow natural expression of fine grained parallelism. It also employs an applicative or functional procedure invocation mechanism, which makes it easy for compilers to extract coarse grained parallelism using machine specific program restructuring. Thus BLAZE should allow one to achieve highly parallel execution on multiprocessor architectures, while still providing the user with conceptually sequential control flow. A central goal in the design of BLAZE is portability across a broad range of parallel architectures. The multiple levels of parallelism present in BLAZE code, in principle, allow a compiler to extract the types of parallelism appropriate for the given architecture while neglecting the remainder. The features of BLAZE are described and it is shown how this language would be used in typical scientific programming.

A model for optimizing file access patterns using spatio-temporal parallelism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boonthanome, Nouanesengsy; Patchett, John; Geveci, Berk

2013-01-01

For many years now, I/O read time has been recognized as the primary bottleneck for parallel visualization and analysis of large-scale data. In this paper, we introduce a model that can estimate the read time for a file stored in a parallel filesystem when given the file access pattern. Read times ultimately depend on how the file is stored and the access pattern used to read the file. The file access pattern will be dictated by the type of parallel decomposition used. We employ spatio-temporal parallelism, which combines both spatial and temporal parallelism, to provide greater flexibility to possible filemore » access patterns. Using our model, we were able to configure the spatio-temporal parallelism to design optimized read access patterns that resulted in a speedup factor of approximately 400 over traditional file access patterns.« less

ATM Mutations and the Development of Severe Radiation-Induced Morbidity Following Radiotherapy for Breast Cancer

DTIC Science & Technology

2006-07-01

patients who are carriers of an alteration in this gene . This project is innovative as it represents the first study to use the powerful DHPLC mutation ...development of adverse responses to radiotherapy (5-6). The first gene to have received significant attention was the mutated in ataxia telangiectasia (AT...Group and Concannon PJ. 2003. Designing and implementing quality control for multi-center screening of mutations in the ATM gene among women with

Prehospital and En Route Analgesic Use in the Combat Setting: A Prospectively Designed, Multicenter, Observational Study

DTIC Science & Technology

2015-03-01

combat medic has access to both opioid and nonopioid analgesics.3 Morphine and fentanyl are effective opioid analgesics and are commonly used...transmucosal (TM) fentanyl8,9 or parenteral ketamine. YM fentanyl has been shown to be a safe, effective, and easy method of administer- ing analgesics in a...a subsequent different drug, or the same drug via an alternative route). Ketamine was most frequently administered, followed by fentanyl , mor- phine

Balloon expandable transcatheter aortic valve implantation with or without pre-dilation of the aortic valve - rationale and design of a multicenter registry (EASE-IT).

PubMed

Bramlage, Peter; Strauch, Justus; Schröfel, Holger

2014-11-18

In patients with severe calcific aortic stenosis, balloon aortic valvuloplasty (BAV) is routinely performed in order to pre-dilate the stenosed aortic valve prior to transcatheter aortic valve implantation (TAVI). Although pre-dilation is considered to be essential for the preparation of the valve landing zone, there is no clear evidence to support its clinical value. In contrast, BAV has been suggested to be linked to several complications. Notably, while preliminary evidence has supported the feasibility and safety of TAVI without pre-dilation, larger studies directly comparing the benefit/risk profile of TAVI in the presence and absence of pre-dilation are required. Therefore, a prospective, two-armed, multicenter registry (EASE-IT) was designed to obtain essential data concerning procedural success rates, adverse events, and mortality in a large cohort of patients undergoing transapical (TA)-TAVI using the Edwards SAPIEN 3 balloon expandable heart valves with and without pre-ballooning. Data provided by EASE-IT will be used to assess the relevance of BAV during the TAVI procedure and to investigate associations between patient characteristics and outcomes. Therefore, results obtained from the EASE-IT registry could contribute to reduced rates of TAVI-associated morbidity and mortality in patients with severe, calcific aortic stenosis. ClinicalTrials.gov Identifier: NCT02127580.

Chemoradiation in elderly esophageal cancer patients: rationale and design of a phase I/II multicenter study (OSAGE).

PubMed

Servagi-Vernat, Stéphanie; Créhange, Gilles; Bonnetain, Franck; Mertens, Cécile; Brain, Etienne; Bosset, Jean François

2017-07-13

The management of elderly patients with cancer is a therapeutic challenge and a public health problem. Definitive chemoradiotherapy (CRT) is an accepted standard treatment for patients with locally advanced esophageal cancer who cannot undergo surgery. However, there are few reports regarding tolerance to CRT in elderly patients. We previously reported results for CRT in patients aged ≥75 years. Following this first phase II trial, we propose to conduct a phase I/II study to evaluate the combination of carboplatin and paclitaxel, with concurrent RT in unresectable esophageal cancer patients aged 75 years or older. This prospective multicenter phase I/II study will include esophageal cancer in patients aged 75 years or older. Study procedures will consist to determinate the tolerated dose of chemotherapy (Carboplatin, paclitaxel) and of radiotherapy (41.4-45 and 50.4 Gy) in the phase I. Efficacy will be assessed using a co-primary endpoint encompassing health related quality of life and the progression-free survival in the phase II with the dose recommended of CRT in the phase I. This geriatric evaluation was defined by the French geriatric oncology group (GERICO). This trial has been designed to assess the tolerated dose of CRT in selected patient aged 75 years or older. Clinicaltrials.gov ID: NCT02735057 . Registered on 18 March 2016.

The Implementation Of Solid State Switches In A Parallel Configuration To Gain Output Current Capacity In A High Current Capacitive Discharge Unit (CDU).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chaves, Mario Paul

2017-07-01

For my project I have selected to research and design a high current pulse system, which will be externally triggered from a 5V pulse. The research will be conducted in the region of paralleling the solid state switches for a higher current output, as well as to see if there will be any other advantages in doing so. The end use of the paralleled solid state switches will be used on a Capacitive Discharge Unit (CDU). For the first part of my project, I have set my focus on the design of the circuit, selection of components, and simulation ofmore » the circuit.« less

An Old Story in the Parallel Synthesis World: An Approach to Hydantoin Libraries.

PubMed

Bogolubsky, Andrey V; Moroz, Yurii S; Savych, Olena; Pipko, Sergey; Konovets, Angelika; Platonov, Maxim O; Vasylchenko, Oleksandr V; Hurmach, Vasyl V; Grygorenko, Oleksandr O

2018-01-08

An approach to the parallel synthesis of hydantoin libraries by reaction of in situ generated 2,2,2-trifluoroethylcarbamates and α-amino esters was developed. To demonstrate utility of the method, a library of 1158 hydantoins designed according to the lead-likeness criteria (MW 200-350, cLogP 1-3) was prepared. The success rate of the method was analyzed as a function of physicochemical parameters of the products, and it was found that the method can be considered as a tool for lead-oriented synthesis. A hydantoin-bearing submicromolar primary hit acting as an Aurora kinase A inhibitor was discovered with a combination of rational design, parallel synthesis using the procedures developed, in silico and in vitro screenings.

Efficient method to design RF pulses for parallel excitation MRI using gridding and conjugate gradient

PubMed Central

Feng, Shuo

2014-01-01

Parallel excitation (pTx) techniques with multiple transmit channels have been widely used in high field MRI imaging to shorten the RF pulse duration and/or reduce the specific absorption rate (SAR). However, the efficiency of pulse design still needs substantial improvement for practical real-time applications. In this paper, we present a detailed description of a fast pulse design method with Fourier domain gridding and a conjugate gradient method. Simulation results of the proposed method show that the proposed method can design pTx pulses at an efficiency 10 times higher than that of the conventional conjugate-gradient based method, without reducing the accuracy of the desirable excitation patterns. PMID:24834420

Efficient method to design RF pulses for parallel excitation MRI using gridding and conjugate gradient.

PubMed

Feng, Shuo; Ji, Jim

2014-04-01

Parallel excitation (pTx) techniques with multiple transmit channels have been widely used in high field MRI imaging to shorten the RF pulse duration and/or reduce the specific absorption rate (SAR). However, the efficiency of pulse design still needs substantial improvement for practical real-time applications. In this paper, we present a detailed description of a fast pulse design method with Fourier domain gridding and a conjugate gradient method. Simulation results of the proposed method show that the proposed method can design pTx pulses at an efficiency 10 times higher than that of the conventional conjugate-gradient based method, without reducing the accuracy of the desirable excitation patterns.

A Systolic Array-Based FPGA Parallel Architecture for the BLAST Algorithm

PubMed Central

Guo, Xinyu; Wang, Hong; Devabhaktuni, Vijay

2012-01-01

A design of systolic array-based Field Programmable Gate Array (FPGA) parallel architecture for Basic Local Alignment Search Tool (BLAST) Algorithm is proposed. BLAST is a heuristic biological sequence alignment algorithm which has been used by bioinformatics experts. In contrast to other designs that detect at most one hit in one-clock-cycle, our design applies a Multiple Hits Detection Module which is a pipelining systolic array to search multiple hits in a single-clock-cycle. Further, we designed a Hits Combination Block which combines overlapping hits from systolic array into one hit. These implementations completed the first and second step of BLAST architecture and achieved significant speedup comparing with previously published architectures. PMID:25969747

Can sequential parallel comparison design and two-way enriched design be useful in medical device clinical trials?

PubMed

Ivanova, Anastasia; Zhang, Zhiwei; Thompson, Laura; Yang, Ying; Kotz, Richard M; Fang, Xin

2016-01-01

Sequential parallel comparison design (SPCD) was proposed for trials with high placebo response. In the first stage of SPCD subjects are randomized between placebo and active treatment. In the second stage placebo nonresponders are re-randomized between placebo and active treatment. Data from the population of "all comers" and the subpopulations of placebo nonresponders then combined to yield a single p-value for treatment comparison. Two-way enriched design (TED) is an extension of SPCD where active treatment responders are also re-randomized between placebo and active treatment in Stage 2. This article investigates the potential uses of SPCD and TED in medical device trials.

Multicenter Patch Testing With Methylisothiazolinone and Methylchloroisothiazolinone/Methylisothiazolinone Within the International Contact Dermatitis Research Group.

PubMed

Isaksson, Marléne; Ale, Iris; Andersen, Klaus E; Elsner, Peter; Goh, Chee-Leok; Goossens, An; Jerajani, Hemangi; Matsunaga, Kayoko; McFadden, John; Bruze, Magnus

The preservatives methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) and MI are well-known contact sensitizers. Recently, an increase in the contact allergy frequency for MI 0.2% aqueous (aq) has been seen in many European countries paralleled with an increase in MCI/MI allergy. Many of the MI-allergic patients do not react to MCI/MI 0.01% or 0.02% because the concentration of MI in these preparations is too low (25 and 50 ppm, respectively) to elicit a positive patch test reaction. The aims of this study were to investigate the prevalence of contact allergy to MI in the participating clinics representing various countries all over the world, to assess how many additional individuals with contact allergy are found by testing MI 0.2% aq in parallel with MCI/MI 0.02%, and to assess the clinical relevance of MI and MCI/MI allergies. In 9 dermatology clinics representing 9 countries, 3865 consecutive patients with dermatitis were patch tested with MI 0.2% aq and in parallel with MCI/MI 0.02% aq, provisionally included into the baseline series. An assessment of clinical relevance in those allergic to MI was also made. Contact allergy to MI was found in 284 patients (7.3%). The frequency of contact allergy varied from 0.8% to 10.9% in different centers. Simultaneous reactivity to 200 ppm of MCI/MI was found in 67.3% of the MI-positive patients. Contact allergy to MI alone without any simultaneous contact allergy to 200 ppm of MCI/MI was diagnosed in 93 patients (32.7%; 2.4% of all tested patients). The contact allergy to MI and/or MCI/MI could explain or contribute to dermatitis in more than 60% of the MI-allergic patients. Methylisothiazolinone of 2000 ppm needs to be patch tested on its own to not miss contact allergy.

Performance of the Galley Parallel File System

NASA Technical Reports Server (NTRS)

Nieuwejaar, Nils; Kotz, David

1996-01-01

As the input/output (I/O) needs of parallel scientific applications increase, file systems for multiprocessors are being designed to provide applications with parallel access to multiple disks. Many parallel file systems present applications with a conventional Unix-like interface that allows the application to access multiple disks transparently. This interface conceals the parallism within the file system, which increases the ease of programmability, but makes it difficult or impossible for sophisticated programmers and libraries to use knowledge about their I/O needs to exploit that parallelism. Furthermore, most current parallel file systems are optimized for a different workload than they are being asked to support. We introduce Galley, a new parallel file system that is intended to efficiently support realistic parallel workloads. Initial experiments, reported in this paper, indicate that Galley is capable of providing high-performance 1/O to applications the applications that rely on them. In Section 3 we describe that access data in patterns that have been observed to be common.

Accuracy analysis and design of A3 parallel spindle head

NASA Astrophysics Data System (ADS)

Ni, Yanbing; Zhang, Biao; Sun, Yupeng; Zhang, Yuan

2016-03-01

As functional components of machine tools, parallel mechanisms are widely used in high efficiency machining of aviation components, and accuracy is one of the critical technical indexes. Lots of researchers have focused on the accuracy problem of parallel mechanisms, but in terms of controlling the errors and improving the accuracy in the stage of design and manufacturing, further efforts are required. Aiming at the accuracy design of a 3-DOF parallel spindle head(A3 head), its error model, sensitivity analysis and tolerance allocation are investigated. Based on the inverse kinematic analysis, the error model of A3 head is established by using the first-order perturbation theory and vector chain method. According to the mapping property of motion and constraint Jacobian matrix, the compensatable and uncompensatable error sources which affect the accuracy in the end-effector are separated. Furthermore, sensitivity analysis is performed on the uncompensatable error sources. The sensitivity probabilistic model is established and the global sensitivity index is proposed to analyze the influence of the uncompensatable error sources on the accuracy in the end-effector of the mechanism. The results show that orientation error sources have bigger effect on the accuracy in the end-effector. Based upon the sensitivity analysis results, the tolerance design is converted into the issue of nonlinearly constrained optimization with the manufacturing cost minimum being the optimization objective. By utilizing the genetic algorithm, the allocation of the tolerances on each component is finally determined. According to the tolerance allocation results, the tolerance ranges of ten kinds of geometric error sources are obtained. These research achievements can provide fundamental guidelines for component manufacturing and assembly of this kind of parallel mechanisms.

Evaluation of the Efficacy and Safety of the Lercanidipine/Valsartan Combination in Korean Patients With Essential Hypertension Not Adequately Controlled With Lercanidipine Monotherapy: A Randomized, Multicenter, Parallel Design, Phase III Clinical Trial.

PubMed

Na, Sang-Hoon; Lee, Hae-Young; Hong Baek, Sang; Jeon, Hui-Kyung; Kang, Jin-Ho; Kim, Yoon-Nyun; Park, Chang-Gyu; Ryu, Jae-Kean; Rhee, Moo-Yong; Kim, Moo-Hyun; Hong, Taek-Jong; Choi, Dong-Ju; Cho, Seong-Wook; Cha, Dong-Hun; Jeon, Eun-Seok; Kim, Jae-Joong; Shin, Joon-Han; Park, Sung-Ha; Lee, Seung-Hwan; John, Sung-Hee; Shin, Eun-Seok; Kim, Nam-Ho; Lee, Sung-Yun; Kwan, Jun; Jeong, Myung-Ho; Kim, Sang-Wook; Jeong, Jin-Ok; Kim, Dong-Woon; Lee, Nam-Ho; Park, Woo-Jung; Ahn, Jeong-Cheon; Won, Kyung-Heon; Uk Lee, Seung; Cho, Jang-Hyun; Kim, Soon-Kil; Ahn, Taehoon; Hong, Sukkeun; Yoo, Sang-Yong; Kim, Song-Yi; Kim, Byung-Soo; Juhn, Jae-Hyeon; Kim, Sun-Young; Lee, Yu-Jeong; Oh, Byung-Hee

2015-08-01

The objective of this study was to evaluate the efficacy and safety of the lercanidipine/valsartan combination compared with lercanidipine monotherapy in patients with hypertension. Part 1 of this study was the randomized, multicenter, double-blind, parallel group, Phase III, 8-week clinical trial to compare superiority of lercanidipine 10 mg/valsartan 80 mg (L10/V80) and lercanidipine 10 mg/valsartan 160 mg (L10/V160) combinations with lercanidipine 10 mg (L10) monotherapy. At screening, hypertensive patients, whose diastolic blood pressure (DBP) was >90 mm Hg after 4 weeks with L10, were randomized to 3 groups of L10, L10/V80, and L10/V160. The primary end point was the change in the mean sitting DBP from baseline (week 0) after 8 weeks of therapy. Patients who were randomly assigned to L10/V160 and whose mean DBP was still ≥ 90 mm Hg in part 1 were enrolled to the up-titration extension study with lercanidipine 20 mg/valsartan 160 mg (L20/V160) (part 2). Of 772 patients screened, 497 were randomized to 3 groups (166 in the L10 group, 168 in the L10/V80 group, and 163 in the L10/V160 group). Mean (SD) age was 55 (9.9) years, and male patients comprised 69%. The mean (SD) baseline systolic blood pressure (SBP)/DBP were 148.4 (15.1)/94.3 (9.5) mm Hg. No significant differences were found between groups in baseline characteristics except the percentages of previous history of antihypertensive medication. The primary end points, the changes of mean (SD) DBP at week 8 from the baseline were -2.0 (8.8) mm Hg in the L10 group, -6.7 (8.5) mm Hg in L10/V80 group, and -8.1 (8.4) mm Hg in L10/V160 group. The adjusted mean difference between the combination groups and the L10 monotherapy group was -4.6 mm Hg (95% CI, -6.5 to -2.6; P < 0.001) in the L10/V80 group and -5.9 mm Hg (95% CI, -7.9 to -4.0, P < 0.001) in the L10/V160 group, which had significantly greater efficacy in BP lowering. A total of 74 patients were enrolled in the part 2 extension study. Changes of mean (SD) DBP and SBP from week 8 to week 12 and week 16 were -5.6 (7.9)/-8.0 (12.0) mm Hg and -5.5 (7.0)/-8.5 (11.3) mm Hg, respectively. For evaluation of the safety profile, the frequencies of adverse events between groups were also not significantly different. The most frequently reported adverse events were headache (6 cases, 20.7%) in the L10 group, dizziness (8 cases, 16.3%) in L10/V80 group, and nasopharyngitis (3 cases, 9.4%) in L10/V160 group, and the incidences of adverse events were not different between groups. Treatment of L10/V80 or L10/V160 combination therapy resulted in significantly greater BP lowering compared with L10 monotherapy. Moreover, the L20/V160 high dose combination had additional BP lowering effect compared with nonresponders with the L10/V160 combination. ClinicalTrials.gov: NCT01928628. Copyright © 2015 Elsevier HS Journals, Inc. All rights reserved.

Big Data: A Parallel Particle Swarm Optimization-Back-Propagation Neural Network Algorithm Based on MapReduce

PubMed Central

Cao, Jianfang; Cui, Hongyan; Shi, Hao; Jiao, Lijuan

2016-01-01

A back-propagation (BP) neural network can solve complicated random nonlinear mapping problems; therefore, it can be applied to a wide range of problems. However, as the sample size increases, the time required to train BP neural networks becomes lengthy. Moreover, the classification accuracy decreases as well. To improve the classification accuracy and runtime efficiency of the BP neural network algorithm, we proposed a parallel design and realization method for a particle swarm optimization (PSO)-optimized BP neural network based on MapReduce on the Hadoop platform using both the PSO algorithm and a parallel design. The PSO algorithm was used to optimize the BP neural network’s initial weights and thresholds and improve the accuracy of the classification algorithm. The MapReduce parallel programming model was utilized to achieve parallel processing of the BP algorithm, thereby solving the problems of hardware and communication overhead when the BP neural network addresses big data. Datasets on 5 different scales were constructed using the scene image library from the SUN Database. The classification accuracy of the parallel PSO-BP neural network algorithm is approximately 92%, and the system efficiency is approximately 0.85, which presents obvious advantages when processing big data. The algorithm proposed in this study demonstrated both higher classification accuracy and improved time efficiency, which represents a significant improvement obtained from applying parallel processing to an intelligent algorithm on big data. PMID:27304987

Computational mechanics analysis tools for parallel-vector supercomputers

NASA Technical Reports Server (NTRS)

Storaasli, O. O.; Nguyen, D. T.; Baddourah, M. A.; Qin, J.

1993-01-01

Computational algorithms for structural analysis on parallel-vector supercomputers are reviewed. These parallel algorithms, developed by the authors, are for the assembly of structural equations, 'out-of-core' strategies for linear equation solution, massively distributed-memory equation solution, unsymmetric equation solution, general eigen-solution, geometrically nonlinear finite element analysis, design sensitivity analysis for structural dynamics, optimization algorithm and domain decomposition. The source code for many of these algorithms is available from NASA Langley.

A New Approach to Parallel Dynamic Partitioning for Adaptive Unstructured Meshes

NASA Technical Reports Server (NTRS)

Heber, Gerd; Biswas, Rupak; Gao, Guang R.

1999-01-01

Classical mesh partitioning algorithms were designed for rather static situations, and their straightforward application in a dynamical framework may lead to unsatisfactory results, e.g., excessive data migration among processors. Furthermore, special attention should be paid to their amenability to parallelization. In this paper, a novel parallel method for the dynamic partitioning of adaptive unstructured meshes is described. It is based on a linear representation of the mesh using self-avoiding walks.

Coding for parallel execution of hardware-in-the-loop millimeter-wave scene generation models on multicore SIMD processor architectures

NASA Astrophysics Data System (ADS)

Olson, Richard F.

2013-05-01

Rendering of point scatterer based radar scenes for millimeter wave (mmW) seeker tests in real-time hardware-in-the-loop (HWIL) scene generation requires efficient algorithms and vector-friendly computer architectures for complex signal synthesis. New processor technology from Intel implements an extended 256-bit vector SIMD instruction set (AVX, AVX2) in a multi-core CPU design providing peak execution rates of hundreds of GigaFLOPS (GFLOPS) on one chip. Real world mmW scene generation code can approach peak SIMD execution rates only after careful algorithm and source code design. An effective software design will maintain high computing intensity emphasizing register-to-register SIMD arithmetic operations over data movement between CPU caches or off-chip memories. Engineers at the U.S. Army Aviation and Missile Research, Development and Engineering Center (AMRDEC) applied two basic parallel coding methods to assess new 256-bit SIMD multi-core architectures for mmW scene generation in HWIL. These include use of POSIX threads built on vector library functions and more portable, highlevel parallel code based on compiler technology (e.g. OpenMP pragmas and SIMD autovectorization). Since CPU technology is rapidly advancing toward high processor core counts and TeraFLOPS peak SIMD execution rates, it is imperative that coding methods be identified which produce efficient and maintainable parallel code. This paper describes the algorithms used in point scatterer target model rendering, the parallelization of those algorithms, and the execution performance achieved on an AVX multi-core machine using the two basic parallel coding methods. The paper concludes with estimates for scale-up performance on upcoming multi-core technology.

Optimization of a new flow design for solid oxide cells using computational fluid dynamics modelling

NASA Astrophysics Data System (ADS)

Duhn, Jakob Dragsbæk; Jensen, Anker Degn; Wedel, Stig; Wix, Christian

2016-12-01

Design of a gas distributor to distribute gas flow into parallel channels for Solid Oxide Cells (SOC) is optimized, with respect to flow distribution, using Computational Fluid Dynamics (CFD) modelling. The CFD model is based on a 3d geometric model and the optimized structural parameters include the width of the channels in the gas distributor and the area in front of the parallel channels. The flow of the optimized design is found to have a flow uniformity index value of 0.978. The effects of deviations from the assumptions used in the modelling (isothermal and non-reacting flow) are evaluated and it is found that a temperature gradient along the parallel channels does not affect the flow uniformity, whereas a temperature difference between the channels does. The impact of the flow distribution on the maximum obtainable conversion during operation is also investigated and the obtainable overall conversion is found to be directly proportional to the flow uniformity. Finally the effect of manufacturing errors is investigated. The design is shown to be robust towards deviations from design dimensions of at least ±0.1 mm which is well within obtainable tolerances.

Massively parallel information processing systems for space applications

NASA Technical Reports Server (NTRS)

Schaefer, D. H.

1979-01-01

NASA is developing massively parallel systems for ultra high speed processing of digital image data collected by satellite borne instrumentation. Such systems contain thousands of processing elements. Work is underway on the design and fabrication of the 'Massively Parallel Processor', a ground computer containing 16,384 processing elements arranged in a 128 x 128 array. This computer uses existing technology. Advanced work includes the development of semiconductor chips containing thousands of feedthrough paths. Massively parallel image analog to digital conversion technology is also being developed. The goal is to provide compact computers suitable for real-time onboard processing of images.

Formalization, equivalence and generalization of basic resonance electrical circuits

NASA Astrophysics Data System (ADS)

Penev, Dimitar; Arnaudov, Dimitar; Hinov, Nikolay

2017-12-01

In the work are presented basic resonance circuits, which are used in resonance energy converters. The following resonant circuits are considered: serial, serial with parallel load parallel capacitor, parallel and parallel with serial loaded inductance. For the circuits under consideration, expressions are generated for the frequencies of own oscillations and for the equivalence of the active power emitted in the load. Mathematical expressions are graphically constructed and verified using computer simulations. The results obtained are used in the model based design of resonant energy converters with DC or AC output. This guaranteed the output indicators of power electronic devices.

Programming parallel architectures: The BLAZE family of languages

NASA Technical Reports Server (NTRS)

Mehrotra, Piyush

1988-01-01

Programming multiprocessor architectures is a critical research issue. An overview is given of the various approaches to programming these architectures that are currently being explored. It is argued that two of these approaches, interactive programming environments and functional parallel languages, are particularly attractive since they remove much of the burden of exploiting parallel architectures from the user. Also described is recent work by the author in the design of parallel languages. Research on languages for both shared and nonshared memory multiprocessors is described, as well as the relations of this work to other current language research projects.

Rubus: A compiler for seamless and extensible parallelism.

PubMed

Adnan, Muhammad; Aslam, Faisal; Nawaz, Zubair; Sarwar, Syed Mansoor

2017-01-01

Nowadays, a typical processor may have multiple processing cores on a single chip. Furthermore, a special purpose processing unit called Graphic Processing Unit (GPU), originally designed for 2D/3D games, is now available for general purpose use in computers and mobile devices. However, the traditional programming languages which were designed to work with machines having single core CPUs, cannot utilize the parallelism available on multi-core processors efficiently. Therefore, to exploit the extraordinary processing power of multi-core processors, researchers are working on new tools and techniques to facilitate parallel programming. To this end, languages like CUDA and OpenCL have been introduced, which can be used to write code with parallelism. The main shortcoming of these languages is that programmer needs to specify all the complex details manually in order to parallelize the code across multiple cores. Therefore, the code written in these languages is difficult to understand, debug and maintain. Furthermore, to parallelize legacy code can require rewriting a significant portion of code in CUDA or OpenCL, which can consume significant time and resources. Thus, the amount of parallelism achieved is proportional to the skills of the programmer and the time spent in code optimizations. This paper proposes a new open source compiler, Rubus, to achieve seamless parallelism. The Rubus compiler relieves the programmer from manually specifying the low-level details. It analyses and transforms a sequential program into a parallel program automatically, without any user intervention. This achieves massive speedup and better utilization of the underlying hardware without a programmer's expertise in parallel programming. For five different benchmarks, on average a speedup of 34.54 times has been achieved by Rubus as compared to Java on a basic GPU having only 96 cores. Whereas, for a matrix multiplication benchmark the average execution speedup of 84 times has been achieved by Rubus on the same GPU. Moreover, Rubus achieves this performance without drastically increasing the memory footprint of a program.

Rubus: A compiler for seamless and extensible parallelism

PubMed Central

Adnan, Muhammad; Aslam, Faisal; Sarwar, Syed Mansoor

2017-01-01

Nowadays, a typical processor may have multiple processing cores on a single chip. Furthermore, a special purpose processing unit called Graphic Processing Unit (GPU), originally designed for 2D/3D games, is now available for general purpose use in computers and mobile devices. However, the traditional programming languages which were designed to work with machines having single core CPUs, cannot utilize the parallelism available on multi-core processors efficiently. Therefore, to exploit the extraordinary processing power of multi-core processors, researchers are working on new tools and techniques to facilitate parallel programming. To this end, languages like CUDA and OpenCL have been introduced, which can be used to write code with parallelism. The main shortcoming of these languages is that programmer needs to specify all the complex details manually in order to parallelize the code across multiple cores. Therefore, the code written in these languages is difficult to understand, debug and maintain. Furthermore, to parallelize legacy code can require rewriting a significant portion of code in CUDA or OpenCL, which can consume significant time and resources. Thus, the amount of parallelism achieved is proportional to the skills of the programmer and the time spent in code optimizations. This paper proposes a new open source compiler, Rubus, to achieve seamless parallelism. The Rubus compiler relieves the programmer from manually specifying the low-level details. It analyses and transforms a sequential program into a parallel program automatically, without any user intervention. This achieves massive speedup and better utilization of the underlying hardware without a programmer’s expertise in parallel programming. For five different benchmarks, on average a speedup of 34.54 times has been achieved by Rubus as compared to Java on a basic GPU having only 96 cores. Whereas, for a matrix multiplication benchmark the average execution speedup of 84 times has been achieved by Rubus on the same GPU. Moreover, Rubus achieves this performance without drastically increasing the memory footprint of a program. PMID:29211758

LDRD final report on massively-parallel linear programming : the parPCx system.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parekh, Ojas; Phillips, Cynthia Ann; Boman, Erik Gunnar

2005-02-01

This report summarizes the research and development performed from October 2002 to September 2004 at Sandia National Laboratories under the Laboratory-Directed Research and Development (LDRD) project ''Massively-Parallel Linear Programming''. We developed a linear programming (LP) solver designed to use a large number of processors. LP is the optimization of a linear objective function subject to linear constraints. Companies and universities have expended huge efforts over decades to produce fast, stable serial LP solvers. Previous parallel codes run on shared-memory systems and have little or no distribution of the constraint matrix. We have seen no reports of general LP solver runsmore » on large numbers of processors. Our parallel LP code is based on an efficient serial implementation of Mehrotra's interior-point predictor-corrector algorithm (PCx). The computational core of this algorithm is the assembly and solution of a sparse linear system. We have substantially rewritten the PCx code and based it on Trilinos, the parallel linear algebra library developed at Sandia. Our interior-point method can use either direct or iterative solvers for the linear system. To achieve a good parallel data distribution of the constraint matrix, we use a (pre-release) version of a hypergraph partitioner from the Zoltan partitioning library. We describe the design and implementation of our new LP solver called parPCx and give preliminary computational results. We summarize a number of issues related to efficient parallel solution of LPs with interior-point methods including data distribution, numerical stability, and solving the core linear system using both direct and iterative methods. We describe a number of applications of LP specific to US Department of Energy mission areas and we summarize our efforts to integrate parPCx (and parallel LP solvers in general) into Sandia's massively-parallel integer programming solver PICO (Parallel Interger and Combinatorial Optimizer). We conclude with directions for long-term future algorithmic research and for near-term development that could improve the performance of parPCx.« less

Performance of the SERI parallel-passage dehumidifer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schlepp, D.; Barlow, R.

1984-09-01

The key component in improving the performance of solar desiccant cooling systems is the dehumidifier. A parallel-passage geometry for the desiccant dehumidifier has been identified as meeting key criteria of low pressure drop, high mass transfer efficiency, and compact size. An experimental program to build and test a small-scale prototype of this design was undertaken in FY 1982, and the results are presented in this report. Computer models to predict the adsorption/desorption behavior of desiccant dehumidifiers were updated to take into account the geometry of the bed and predict potential system performance using the new component design. The parallel-passage designmore » proved to have high mass transfer effectiveness and low pressure drop over a wide range of test conditions typical of desiccant cooling system operation. The prototype dehumidifier averaged 93% effectiveness at pressure drops of less than 50 Pa at design point conditions. Predictions of system performance using models validated with the experimental data indicate that system thermal coefficients of performance (COPs) of 1.0 to 1.2 and electrical COPs above 8.5 are possible using this design.« less

Distributed Parallel Processing and Dynamic Load Balancing Techniques for Multidisciplinary High Speed Aircraft Design

NASA Technical Reports Server (NTRS)

Krasteva, Denitza T.

1998-01-01

Multidisciplinary design optimization (MDO) for large-scale engineering problems poses many challenges (e.g., the design of an efficient concurrent paradigm for global optimization based on disciplinary analyses, expensive computations over vast data sets, etc.) This work focuses on the application of distributed schemes for massively parallel architectures to MDO problems, as a tool for reducing computation time and solving larger problems. The specific problem considered here is configuration optimization of a high speed civil transport (HSCT), and the efficient parallelization of the embedded paradigm for reasonable design space identification. Two distributed dynamic load balancing techniques (random polling and global round robin with message combining) and two necessary termination detection schemes (global task count and token passing) were implemented and evaluated in terms of effectiveness and scalability to large problem sizes and a thousand processors. The effect of certain parameters on execution time was also inspected. Empirical results demonstrated stable performance and effectiveness for all schemes, and the parametric study showed that the selected algorithmic parameters have a negligible effect on performance.

Optimizing trial design in pharmacogenetics research: comparing a fixed parallel group, group sequential, and adaptive selection design on sample size requirements.

PubMed

Boessen, Ruud; van der Baan, Frederieke; Groenwold, Rolf; Egberts, Antoine; Klungel, Olaf; Grobbee, Diederick; Knol, Mirjam; Roes, Kit

2013-01-01

Two-stage clinical trial designs may be efficient in pharmacogenetics research when there is some but inconclusive evidence of effect modification by a genomic marker. Two-stage designs allow to stop early for efficacy or futility and can offer the additional opportunity to enrich the study population to a specific patient subgroup after an interim analysis. This study compared sample size requirements for fixed parallel group, group sequential, and adaptive selection designs with equal overall power and control of the family-wise type I error rate. The designs were evaluated across scenarios that defined the effect sizes in the marker positive and marker negative subgroups and the prevalence of marker positive patients in the overall study population. Effect sizes were chosen to reflect realistic planning scenarios, where at least some effect is present in the marker negative subgroup. In addition, scenarios were considered in which the assumed 'true' subgroup effects (i.e., the postulated effects) differed from those hypothesized at the planning stage. As expected, both two-stage designs generally required fewer patients than a fixed parallel group design, and the advantage increased as the difference between subgroups increased. The adaptive selection design added little further reduction in sample size, as compared with the group sequential design, when the postulated effect sizes were equal to those hypothesized at the planning stage. However, when the postulated effects deviated strongly in favor of enrichment, the comparative advantage of the adaptive selection design increased, which precisely reflects the adaptive nature of the design. Copyright © 2013 John Wiley & Sons, Ltd.

A high-speed linear algebra library with automatic parallelism

NASA Technical Reports Server (NTRS)

Boucher, Michael L.

1994-01-01

Parallel or distributed processing is key to getting highest performance workstations. However, designing and implementing efficient parallel algorithms is difficult and error-prone. It is even more difficult to write code that is both portable to and efficient on many different computers. Finally, it is harder still to satisfy the above requirements and include the reliability and ease of use required of commercial software intended for use in a production environment. As a result, the application of parallel processing technology to commercial software has been extremely small even though there are numerous computationally demanding programs that would significantly benefit from application of parallel processing. This paper describes DSSLIB, which is a library of subroutines that perform many of the time-consuming computations in engineering and scientific software. DSSLIB combines the high efficiency and speed of parallel computation with a serial programming model that eliminates many undesirable side-effects of typical parallel code. The result is a simple way to incorporate the power of parallel processing into commercial software without compromising maintainability, reliability, or ease of use. This gives significant advantages over less powerful non-parallel entries in the market.

Factors predicting survival in ALS: a multicenter Italian study.

PubMed

Calvo, Andrea; Moglia, Cristina; Lunetta, Christian; Marinou, Kalliopi; Ticozzi, Nicola; Ferrante, Gianluca Drago; Scialo, Carlo; Sorarù, Gianni; Trojsi, Francesca; Conte, Amelia; Falzone, Yuri M; Tortelli, Rosanna; Russo, Massimo; Chiò, Adriano; Sansone, Valeria Ada; Mora, Gabriele; Silani, Vincenzo; Volanti, Paolo; Caponnetto, Claudia; Querin, Giorgia; Monsurrò, Maria Rosaria; Sabatelli, Mario; Riva, Nilo; Logroscino, Giancarlo; Messina, Sonia; Fini, Nicola; Mandrioli, Jessica

2017-01-01

The aim of this multicenter, retrospective study is to investigate the role of clinical characteristics and therapeutic intervention on ALS prognosis. The study included patients diagnosed from January 1, 2009 to December 31, 2013 in 13 Italian referral centers for ALS located in 10 Italian regions. Caring neurologists collected a detailed phenotypic profile and follow-up data until death into an electronic database. One center collected also data from a population-based registry for ALS. 2648 incident cases were collected. The median survival time from onset to death/tracheostomy was 44 months (SE 1.18, CI 42-46). According to univariate analysis, factors related to survival from onset to death/tracheostomy were: age at onset, diagnostic delay, site of onset, phenotype, degree of certainty at diagnosis according to revised El Escorial criteria (R-EEC), presence/absence of dementia, BMI at diagnosis, patients' provenance. In the multivariate analysis, age at onset, diagnostic delay, phenotypes but not site of onset, presence/absence of dementia, BMI, riluzole use, R-EEC criteria were independent prognostic factors of survival in ALS. We compared patients from an ALS Registry with patients from tertiary centers; the latter ones were younger, less frequently bulbar, but more frequently familial and definite at diagnosis. Our large, multicenter study demonstrated the role of some clinical and demographic factors on ALS survival, and showed some interesting differences between referral centers' patients and the general ALS population. These results can be helpful for clinical practice, in clinical trial design and to validate new tools to predict disease progression.

Multicenter Quality Improvement Project to Prevent Sternal Wound Infections in Pediatric Cardiac Surgery Patients.

PubMed

Woodward, Cathy; Taylor, Richard; Son, Minnette; Taeed, Roozbeh; Jacobs, Marshall L; Kane, Lauren; Jacobs, Jeffrey P; Husain, S Adil

2017-07-01

Children undergoing cardiac surgery are at risk for sternal wound infections (SWIs) leading to increased morbidity and mortality. Single-center quality improvement (QI) initiatives have demonstrated decreased infection rates utilizing a bundled approach. This multicenter project was designed to assess the efficacy of a protocolized approach to decrease SWI. Pediatric cardiac programs joined a collaborative effort to prevent SWI. Programs implemented the protocol, collected compliance data, and provided data points from local clinical registries using Society of Thoracic Surgery Congenital Heart Surgery Database harvest-compliant software or from other registries. Nine programs prospectively collected compliance data on 4,198 children. Days between infections were extended from 68.2 days (range: 25-82) to 130 days (range: 43-412). Protocol compliance increased from 76.7% (first quarter) to 91.3% (final quarter). Ninety (1.9%) children developed an SWI preprotocol and 64 (1.5%) postprotocol, P = .18. The 657 (15%) delayed sternal closure patients had a 5% infection rate with 18 (5.7%) in year 1 and 14 (4.3%) in year 2 P = .43. Delayed sternal closure patients demonstrated a trend toward increased risk for SWI of 1.046 for each day the sternum remained open, P = .067. Children who received appropriately timed preop antibiotics developed less infections than those who did not, 1.9% versus 4.1%, P = .007. A multicenter QI project to reduce pediatric SWIs demonstrated an extension of days between infections and a decrease in SWIs. Patients who received preop antibiotics on time had lower SWI rates than those who did not.

Comparison of 3 biodegradable polymer and durable polymer-based drug-eluting stents in all-comers (BIO-RESORT): rationale and study design of the randomized TWENTE III multicenter trial.

PubMed

Lam, Ming Kai; Sen, Hanim; Tandjung, Kenneth; van Houwelingen, K Gert; de Vries, Arie G; Danse, Peter W; Schotborgh, Carl E; Scholte, Martijn; Löwik, Marije M; Linssen, Gerard C M; Ijzerman, Maarten J; van der Palen, Job; Doggen, Carine J M; von Birgelen, Clemens

2014-04-01

To evaluate the safety and efficacy of 2 novel drug-eluting stents (DES) with biodegradable polymer-based coatings versus a durable coating DES. BIO-RESORT is an investigator-initiated, prospective, patient-blinded, randomized multicenter trial in 3540 Dutch all-comers with various clinical syndromes, requiring percutaneous coronary interventions (PCI) with DES implantation. Randomization (stratified for diabetes mellitus) is being performed in a 1:1:1 ratio between ORSIRO sirolimus-eluting stent with circumferential biodegradable coating, SYNERGY everolimus-eluting stent with abluminal biodegradable coating, and RESOLUTE INTEGRITY zotarolimus-eluting stent with durable coating. The primary endpoint is the incidence of the composite endpoint target vessel failure at 1 year, consisting of cardiac death, target vessel-related myocardial infarction, or clinically driven target vessel revascularization. Power calculation assumes a target vessel failure rate of 8.5% with a 3.5% non-inferiority margin, giving the study a power of 85% (α level .025 adjusted for multiple testing). The impact of diabetes mellitus on post-PCI outcome will be evaluated. The first patient was enrolled on December 21, 2012. BIO-RESORT is a large, prospective, randomized, multicenter trial with three arms, comparing two DES with biodegradable coatings versus a reference DES with a durable coating in 3540 all-comers. The trial will provide novel insights into the clinical outcome of modern DES and will address the impact of known and so far undetected diabetes mellitus on post-PCI outcome. Copyright © 2014 The Authors. Published by Mosby, Inc. All rights reserved.

Stakeholders' views on data sharing in multicenter studies.

PubMed

Mazor, Kathleen M; Richards, Allison; Gallagher, Mia; Arterburn, David E; Raebel, Marsha A; Nowell, W Benjamin; Curtis, Jeffrey R; Paolino, Andrea R; Toh, Sengwee

2017-09-01

To understand stakeholders' views on data sharing in multicenter comparative effectiveness research studies and the value of privacy-protecting methods. Semistructured interviews with five US stakeholder groups. We completed 11 interviews, involving patients (n = 15), researchers (n = 10), Institutional Review Board and regulatory staff (n = 3), multicenter research governance experts (n = 2) and healthcare system leaders (n = 4). Perceptions of the benefits and value of research were the strongest influences toward data sharing; cost and security risks were primary influences against sharing. Privacy-protecting methods that share summary-level data were acknowledged as being appealing, but there were concerns about increased cost and potential loss of research validity. Stakeholders were open to data sharing in multicenter studies that offer value and minimize security risks.

Interlaboratory quality control of total HIV-1 DNA load measurement for multicenter reservoir studies.

PubMed

Gantner, Pierre; Mélard, Adeline; Damond, Florence; Delaugerre, Constance; Dina, Julia; Gueudin, Marie; Maillard, Anne; Sauné, Karine; Rodallec, Audrey; Tuaillon, Edouard; Plantier, Jean-Christophe; Rouzioux, Christine; Avettand-Fenoel, Véronique

2017-11-01

Viral reservoirs represent an important barrier to HIV cure. Accurate markers of HIV reservoirs are needed to develop multicenter studies. The aim of this multicenter quality control (QC) was to evaluate the inter-laboratory reproducibility of total HIV-1-DNA quantification. Ten laboratories of the ANRS-AC11 working group participated by quantifying HIV-DNA with a real-time qPCR assay (Biocentric) in four samples (QCMD). Good reproducibility was found between laboratories (standard deviation ≤ 0.2 log 10 copies/10 6 PBMC) for the three positive QC that were correctly classified by each laboratory (QC1

Design of high-performance parallelized gene predictors in MATLAB.

PubMed

Rivard, Sylvain Robert; Mailloux, Jean-Gabriel; Beguenane, Rachid; Bui, Hung Tien

2012-04-10

This paper proposes a method of implementing parallel gene prediction algorithms in MATLAB. The proposed designs are based on either Goertzel's algorithm or on FFTs and have been implemented using varying amounts of parallelism on a central processing unit (CPU) and on a graphics processing unit (GPU). Results show that an implementation using a straightforward approach can require over 4.5 h to process 15 million base pairs (bps) whereas a properly designed one could perform the same task in less than five minutes. In the best case, a GPU implementation can yield these results in 57 s. The present work shows how parallelism can be used in MATLAB for gene prediction in very large DNA sequences to produce results that are over 270 times faster than a conventional approach. This is significant as MATLAB is typically overlooked due to its apparent slow processing time even though it offers a convenient environment for bioinformatics. From a practical standpoint, this work proposes two strategies for accelerating genome data processing which rely on different parallelization mechanisms. Using a CPU, the work shows that direct access to the MEX function increases execution speed and that the PARFOR construct should be used in order to take full advantage of the parallelizable Goertzel implementation. When the target is a GPU, the work shows that data needs to be segmented into manageable sizes within the GFOR construct before processing in order to minimize execution time.

Increasing airport capacity with modified IFR approach procedures for close-spaced parallel runways

DOT National Transportation Integrated Search

2001-01-01

Because of wake turbulence considerations, current instrument approach : procedures treat close-spaced (i.e., less than 2,500 feet apart) parallel run : ways as a single runway. This restriction is designed to assure safety for all : aircraft types u...

Integrated Joule switches for the control of current dynamics in parallel superconducting strips

NASA Astrophysics Data System (ADS)

Casaburi, A.; Heath, R. M.; Cristiano, R.; Ejrnaes, M.; Zen, N.; Ohkubo, M.; Hadfield, R. H.

2018-06-01

Understanding and harnessing the physics of the dynamic current distribution in parallel superconducting strips holds the key to creating next generation sensors for single molecule and single photon detection. Non-uniformity in the current distribution in parallel superconducting strips leads to low detection efficiency and unstable operation, preventing the scale up to large area sensors. Recent studies indicate that non-uniform current distributions occurring in parallel strips can be understood and modeled in the framework of the generalized London model. Here we build on this important physical insight, investigating an innovative design with integrated superconducting-to-resistive Joule switches to break the superconducting loops between the strips and thus control the current dynamics. Employing precision low temperature nano-optical techniques, we map the uniformity of the current distribution before- and after the resistive strip switching event, confirming the effectiveness of our design. These results provide important insights for the development of next generation large area superconducting strip-based sensors.

Evaluating the performance of parallel subsurface simulators: An illustrative example with PFLOTRAN

PubMed Central

Hammond, G E; Lichtner, P C; Mills, R T

2014-01-01

[1] To better inform the subsurface scientist on the expected performance of parallel simulators, this work investigates performance of the reactive multiphase flow and multicomponent biogeochemical transport code PFLOTRAN as it is applied to several realistic modeling scenarios run on the Jaguar supercomputer. After a brief introduction to the code's parallel layout and code design, PFLOTRAN's parallel performance (measured through strong and weak scalability analyses) is evaluated in the context of conceptual model layout, software and algorithmic design, and known hardware limitations. PFLOTRAN scales well (with regard to strong scaling) for three realistic problem scenarios: (1) in situ leaching of copper from a mineral ore deposit within a 5-spot flow regime, (2) transient flow and solute transport within a regional doublet, and (3) a real-world problem involving uranium surface complexation within a heterogeneous and extremely dynamic variably saturated flow field. Weak scalability is discussed in detail for the regional doublet problem, and several difficulties with its interpretation are noted. PMID:25506097

Evaluating the performance of parallel subsurface simulators: An illustrative example with PFLOTRAN.

PubMed

Hammond, G E; Lichtner, P C; Mills, R T

2014-01-01

[1] To better inform the subsurface scientist on the expected performance of parallel simulators, this work investigates performance of the reactive multiphase flow and multicomponent biogeochemical transport code PFLOTRAN as it is applied to several realistic modeling scenarios run on the Jaguar supercomputer. After a brief introduction to the code's parallel layout and code design, PFLOTRAN's parallel performance (measured through strong and weak scalability analyses) is evaluated in the context of conceptual model layout, software and algorithmic design, and known hardware limitations. PFLOTRAN scales well (with regard to strong scaling) for three realistic problem scenarios: (1) in situ leaching of copper from a mineral ore deposit within a 5-spot flow regime, (2) transient flow and solute transport within a regional doublet, and (3) a real-world problem involving uranium surface complexation within a heterogeneous and extremely dynamic variably saturated flow field. Weak scalability is discussed in detail for the regional doublet problem, and several difficulties with its interpretation are noted.

The AIS-5000 parallel processor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmitt, L.A.; Wilson, S.S.

1988-05-01

The AIS-5000 is a commercially available massively parallel processor which has been designed to operate in an industrial environment. It has fine-grained parallelism with up to 1024 processing elements arranged in a single-instruction multiple-data (SIMD) architecture. The processing elements are arranged in a one-dimensional chain that, for computer vision applications, can be as wide as the image itself. This architecture has superior cost/performance characteristics than two-dimensional mesh-connected systems. The design of the processing elements and their interconnections as well as the software used to program the system allow a wide variety of algorithms and applications to be implemented. In thismore » paper, the overall architecture of the system is described. Various components of the system are discussed, including details of the processing elements, data I/O pathways and parallel memory organization. A virtual two-dimensional model for programming image-based algorithms for the system is presented. This model is supported by the AIS-5000 hardware and software and allows the system to be treated as a full-image-size, two-dimensional, mesh-connected parallel processor. Performance bench marks are given for certain simple and complex functions.« less

A Parallel Framework with Block Matrices of a Discrete Fourier Transform for Vector-Valued Discrete-Time Signals.

PubMed

Soto-Quiros, Pablo

2015-01-01

This paper presents a parallel implementation of a kind of discrete Fourier transform (DFT): the vector-valued DFT. The vector-valued DFT is a novel tool to analyze the spectra of vector-valued discrete-time signals. This parallel implementation is developed in terms of a mathematical framework with a set of block matrix operations. These block matrix operations contribute to analysis, design, and implementation of parallel algorithms in multicore processors. In this work, an implementation and experimental investigation of the mathematical framework are performed using MATLAB with the Parallel Computing Toolbox. We found that there is advantage to use multicore processors and a parallel computing environment to minimize the high execution time. Additionally, speedup increases when the number of logical processors and length of the signal increase.

Genetic Parallel Programming: design and implementation.

PubMed

Cheang, Sin Man; Leung, Kwong Sak; Lee, Kin Hong

2006-01-01

This paper presents a novel Genetic Parallel Programming (GPP) paradigm for evolving parallel programs running on a Multi-Arithmetic-Logic-Unit (Multi-ALU) Processor (MAP). The MAP is a Multiple Instruction-streams, Multiple Data-streams (MIMD), general-purpose register machine that can be implemented on modern Very Large-Scale Integrated Circuits (VLSIs) in order to evaluate genetic programs at high speed. For human programmers, writing parallel programs is more difficult than writing sequential programs. However, experimental results show that GPP evolves parallel programs with less computational effort than that of their sequential counterparts. It creates a new approach to evolving a feasible problem solution in parallel program form and then serializes it into a sequential program if required. The effectiveness and efficiency of GPP are investigated using a suite of 14 well-studied benchmark problems. Experimental results show that GPP speeds up evolution substantially.

Roller-gear drives for robotic manipulators design, fabrication and test

NASA Technical Reports Server (NTRS)

Anderson, William J.; Shipitalo, William

1991-01-01

Two single axis planetary roller-gear drives and a two axis roller-gear drive with dual inputs were designed for use as robotic transmissions. Each of the single axis drives is a two planet row, four planet arrangement with spur gears and compressively loaded cylindrical rollers acting in parallel. The two axis drive employs bevel gears and cone rollers acting in parallel. The rollers serve a dual function: they remove backlash from the system, and they transmit torque when the gears are not fully engaged.

The Area-Time Complexity of Sorting.

DTIC Science & Technology

1984-12-01

suggests a classification of keys into short (k < logn), long (k > 2 logn), and of medium length. Optimal or near-optimal designs of VLSI sorters are...suggests a classification of keys into short (k 4 logn ), long (k > 21ogn ), and of medium length. Optimal or near-optimal designs of VLSI sorters are...ARCHITECTURES 79 5.1 Introduction 79 5.2 Parallel Algorithms for Sorting 80 . 5.3 Parallel Architectures 88 6 OPTIMAL VLSI SORTERS FOR KEYS OF LENGTH k - logn

Experimental entangled photon pair generation using crystals with parallel optical axes.

PubMed

Villar, Aitor; Lohrmann, Alexander; Ling, Alexander

2018-05-14

We present an optical design where polarization-entangled photon pairs are generated within two β-Barium Borate crystals whose optical axes are parallel. This design increases the spatial mode overlap of the emitted photon pairs enhancing single mode collection without the need for additional spatial walk-off compensators. The observed photon pair rate is at least 65 000 pairs/s/mW with a quantum state fidelity of 99.53 ± 0.22% when pumped with an elliptical spatial profile.

A multioutput LLC-type parallel resonant converter

NASA Astrophysics Data System (ADS)

Liu, Rui; Lee, C. Q.; Upadhyay, Anand K.

1992-07-01

When an LLC-type parallel resonant converter (LLC-PRC) operates above resonant frequency, the switching transistors can be turned off at zero voltage. Further study reveals that the LLC-PRC possesses the advantage of lower converter voltage gain as compared with the conventional PRC. Based on analytic results, a complete set of design curves is obtained, from which a systematic design procedure is developed. Experimental results from a 150 W 150 kHz multioutput LLC-type PRC power supply are presented.

[Design and study of parallel computing environment of Monte Carlo simulation for particle therapy planning using a public cloud-computing infrastructure].

PubMed

Yokohama, Noriya

2013-07-01

This report was aimed at structuring the design of architectures and studying performance measurement of a parallel computing environment using a Monte Carlo simulation for particle therapy using a high performance computing (HPC) instance within a public cloud-computing infrastructure. Performance measurements showed an approximately 28 times faster speed than seen with single-thread architecture, combined with improved stability. A study of methods of optimizing the system operations also indicated lower cost.

Experimental entangled photon pair generation using crystals with parallel optical axes

NASA Astrophysics Data System (ADS)

Villar, Aitor; Lohrmann, Alexander; Ling, Alexander

2018-05-01

We present an optical design where polarization-entangled photon pairs are generated within two $\\beta$-Barium Borate crystals whose optical axes are parallel. This design increases the spatial mode overlap of the emitted photon pairs enhancing single mode collection without the need for additional spatial walk-off compensators. The observed photon pair rate is at least 65000 pairs/s/mW with a quantum state fidelity of 99.53$\\pm$0.22% when pumped with an elliptical spatial profile.

Spinal Cord Injury

MedlinePlus

... A recent prospective multicenter trial called STASCIS is exploring whether performing decompression surgery early (less than 24 ... A recent prospective multicenter trial called STASCIS is exploring whether performing decompression surgery early (less than 24 ...

Parallel Aircraft Trajectory Optimization with Analytic Derivatives

NASA Technical Reports Server (NTRS)

Falck, Robert D.; Gray, Justin S.; Naylor, Bret

2016-01-01

Trajectory optimization is an integral component for the design of aerospace vehicles, but emerging aircraft technologies have introduced new demands on trajectory analysis that current tools are not well suited to address. Designing aircraft with technologies such as hybrid electric propulsion and morphing wings requires consideration of the operational behavior as well as the physical design characteristics of the aircraft. The addition of operational variables can dramatically increase the number of design variables which motivates the use of gradient based optimization with analytic derivatives to solve the larger optimization problems. In this work we develop an aircraft trajectory analysis tool using a Legendre-Gauss-Lobatto based collocation scheme, providing analytic derivatives via the OpenMDAO multidisciplinary optimization framework. This collocation method uses an implicit time integration scheme that provides a high degree of sparsity and thus several potential options for parallelization. The performance of the new implementation was investigated via a series of single and multi-trajectory optimizations using a combination of parallel computing and constraint aggregation. The computational performance results show that in order to take full advantage of the sparsity in the problem it is vital to parallelize both the non-linear analysis evaluations and the derivative computations themselves. The constraint aggregation results showed a significant numerical challenge due to difficulty in achieving tight convergence tolerances. Overall, the results demonstrate the value of applying analytic derivatives to trajectory optimization problems and lay the foundation for future application of this collocation based method to the design of aircraft with where operational scheduling of technologies is key to achieving good performance.

Review of Recent Methodological Developments in Group-Randomized Trials: Part 1—Design

PubMed Central

Li, Fan; Gallis, John A.; Prague, Melanie; Murray, David M.

2017-01-01

In 2004, Murray et al. reviewed methodological developments in the design and analysis of group-randomized trials (GRTs). We have highlighted the developments of the past 13 years in design with a companion article to focus on developments in analysis. As a pair, these articles update the 2004 review. We have discussed developments in the topics of the earlier review (e.g., clustering, matching, and individually randomized group-treatment trials) and in new topics, including constrained randomization and a range of randomized designs that are alternatives to the standard parallel-arm GRT. These include the stepped-wedge GRT, the pseudocluster randomized trial, and the network-randomized GRT, which, like the parallel-arm GRT, require clustering to be accounted for in both their design and analysis. PMID:28426295

Review of Recent Methodological Developments in Group-Randomized Trials: Part 1-Design.

PubMed

Turner, Elizabeth L; Li, Fan; Gallis, John A; Prague, Melanie; Murray, David M

2017-06-01

In 2004, Murray et al. reviewed methodological developments in the design and analysis of group-randomized trials (GRTs). We have highlighted the developments of the past 13 years in design with a companion article to focus on developments in analysis. As a pair, these articles update the 2004 review. We have discussed developments in the topics of the earlier review (e.g., clustering, matching, and individually randomized group-treatment trials) and in new topics, including constrained randomization and a range of randomized designs that are alternatives to the standard parallel-arm GRT. These include the stepped-wedge GRT, the pseudocluster randomized trial, and the network-randomized GRT, which, like the parallel-arm GRT, require clustering to be accounted for in both their design and analysis.

Multicenter breast cancer collaborative registry.

PubMed

Sherman, Simon; Shats, Oleg; Fleissner, Elizabeth; Bascom, George; Yiee, Kevin; Copur, Mehmet; Crow, Kate; Rooney, James; Mateen, Zubeena; Ketcham, Marsha A; Feng, Jianmin; Sherman, Alexander; Gleason, Michael; Kinarsky, Leo; Silva-Lopez, Edibaldo; Edney, James; Reed, Elizabeth; Berger, Ann; Cowan, Kenneth

2011-01-01

The Breast Cancer Collaborative Registry (BCCR) is a multicenter web-based system that efficiently collects and manages a variety of data on breast cancer (BC) patients and BC survivors. This registry is designed as a multi-tier web application that utilizes Java Servlet/JSP technology and has an Oracle 11g database as a back-end. The BCCR questionnaire has accommodated standards accepted in breast cancer research and healthcare. By harmonizing the controlled vocabulary with the NCI Thesaurus (NCIt) or Systematized Nomenclature of Medicine-Clinical Terms (SNOMED-CT), the BCCR provides a standardized approach to data collection and reporting. The BCCR has been recently certified by the National Cancer Institute's Center for Biomedical Informatics and Information Technology (NCI CBIIT) as a cancer Biomedical Informatics Grid (caBIG(®)) Bronze Compatible product.The BCCR is aimed at facilitating rapid and uniform collection of critical information and biological samples to be used in developing diagnostic, prevention, treatment, and survivorship strategies against breast cancer. Currently, seven cancer institutions are participating in the BCCR that contains data on almost 900 subjects (BC patients and survivors, as well as individuals at high risk of getting BC).

Multicenter Breast Cancer Collaborative Registry

PubMed Central

Sherman, Simon; Shats, Oleg; Fleissner, Elizabeth; Bascom, George; Yiee, Kevin; Copur, Mehmet; Crow, Kate; Rooney, James; Mateen, Zubeena; Ketcham, Marsha A.; Feng, Jianmin; Sherman, Alexander; Gleason, Michael; Kinarsky, Leo; Silva-Lopez, Edibaldo; Edney, James; Reed, Elizabeth; Berger, Ann; Cowan, Kenneth

2011-01-01

The Breast Cancer Collaborative Registry (BCCR) is a multicenter web-based system that efficiently collects and manages a variety of data on breast cancer (BC) patients and BC survivors. This registry is designed as a multi-tier web application that utilizes Java Servlet/JSP technology and has an Oracle 11g database as a back-end. The BCCR questionnaire has accommodated standards accepted in breast cancer research and healthcare. By harmonizing the controlled vocabulary with the NCI Thesaurus (NCIt) or Systematized Nomenclature of Medicine-Clinical Terms (SNOMED-CT), the BCCR provides a standardized approach to data collection and reporting. The BCCR has been recently certified by the National Cancer Institute’s Center for Biomedical Informatics and Information Technology (NCI CBIIT) as a cancer Biomedical Informatics Grid (caBIG®) Bronze Compatible product. The BCCR is aimed at facilitating rapid and uniform collection of critical information and biological samples to be used in developing diagnostic, prevention, treatment, and survivorship strategies against breast cancer. Currently, seven cancer institutions are participating in the BCCR that contains data on almost 900 subjects (BC patients and survivors, as well as individuals at high risk of getting BC). PMID:21918596

Multi-Center Pilot Study to Evaluate the Safety Pro le of High Energy Fractionated Radiofrequency With Insulated Microneedles to Multiple Levels of the Dermis.

PubMed

Cohen, Joel L; Weiner, Steven F; Pozner, Jason N; Ibrahimi, Omar A; Vasily, David B; Ross, E Victor; Gabriel, Zena

2016-11-01

In this multi-center pilot study, the safety pro le of high intensity focused radiofrequency (RF) delivered to the dermis was evaluated for safety in the treatment of the aging neck and face. A newly designed insulated microneedle system delivers a signi cant coagulative thermal injury into the dermis while sparing the epidermis from RF injury. Thirty- ve healthy subjects from seven aesthetic practices were evaluated, and data from each were incorporated in this case report. The subjects received a single treatment using settings that delivered the highest RF energies suggested from the new recommended protocols. The depth of thermal delivery was adjusted before each pass and all subjects received a minimum of two to three passes to the treated areas. Before and after photographs along with adverse effects were recorded. This case report demonstrates the ability to deliver significant RF thermal injury to several layers of the dermis with insulated microneedles safely with little injury to the epidermis and minimum downtime. J Drugs Dermatol. 2016;15(11):1308-1312..

Dermatology Medical Education: A Multicenter Survey Study of the Undergraduate Perspective of the Dermatology Clinical Clerkship.

PubMed

Davari, Parastoo; Millsop, Jillian W; Johnson, Mary Ann N; Takahashi, Stefani R; Peng, David H; Badger, Joanna; Bahr, Brooks A; Shinkai, Kanade; Li, Chin-Shang; Fazel, Nasim

2017-12-15

Limited data are available regarding the undergraduate dermatology clinical clerkship curriculum in the United States. Our primaryaim is to assess medical students' perspectives of the dermatology clinical clerkship. A multicenter survey study was conducted, which included four California dermatology academic programs. A 17-item questionnaire was designed to investigate medical student perception with regard tothe overall educational value of the various teaching aspects of the dermatology clinical clerkship. A total of 152 medical student surveys were completed. Over half of the medical students felt proficient in diagnosing the most commondermatologic conditions. Eighty-seven percent of medical students were very satisfied with the dermatology clerkship. Ninety-one percent of students felt the length of the clerkship was appropriate. The vast majority of medical students reported a high level of proficiency in the treatment and diagnosis of common skin disorders. In contrast, our findings suggest that medical students may not begaining sufficient hands-on experience in conducting certain dermatologic procedures following the dermatology clerkship. Overall, medical studentperception of the dermatology clinical clerkship was mostly positive.

Blood and Marrow Transplant Clinical Trials Network Report on the Development of Novel Endpoints and Selection of Promising Approaches for Graft-versus-Host Disease Prevention Trials.

PubMed

Pasquini, Marcelo C; Logan, Brent; Jones, Richard J; Alousi, Amin M; Appelbaum, Frederick R; Bolaños-Meade, Javier; Flowers, Mary E D; Giralt, Sergio; Horowitz, Mary M; Jacobsohn, David; Koreth, John; Levine, John E; Luznik, Leo; Maziarz, Richard; Mendizabal, Adam; Pavletic, Steven; Perales, Miguel-Angel; Porter, David; Reshef, Ran; Weisdorf, Daniel; Antin, Joseph H

2018-06-01

Graft-versus-host disease (GVHD) is a common complication after hematopoietic cell transplantation (HCT) and associated with significant morbidity and mortality. Preventing GVHD without chronic therapy or increasing relapse is a desired goal. Here we report a benchmark analysis to evaluate the performance of 6 GVHD prevention strategies tested at single institutions compared with a large multicenter outcomes database as a control. Each intervention was compared with the control for the incidence of acute and chronic GVHD and overall survival and against novel composite endpoints: acute and chronic GVHD, relapse-free survival (GRFS), and chronic GVHD, relapse-free survival (CRFS). Modeling GRFS and CRFS using the benchmark analysis further informed the design of 2 clinical trials testing GVHD prophylaxis interventions. This study demonstrates the potential benefit of using an outcomes database to select promising interventions for multicenter clinical trials and proposes novel composite endpoints for use in GVHD prevention trials. Copyright © 2018 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Reproducibility and variability of quantitative magnetic resonance imaging markers in cerebral small vessel disease

PubMed Central

De Guio, François; Jouvent, Eric; Biessels, Geert Jan; Black, Sandra E; Brayne, Carol; Chen, Christopher; Cordonnier, Charlotte; De Leeuw, Frank-Eric; Dichgans, Martin; Doubal, Fergus; Duering, Marco; Dufouil, Carole; Duzel, Emrah; Fazekas, Franz; Hachinski, Vladimir; Ikram, M Arfan; Linn, Jennifer; Matthews, Paul M; Mazoyer, Bernard; Mok, Vincent; Norrving, Bo; O’Brien, John T; Pantoni, Leonardo; Ropele, Stefan; Sachdev, Perminder; Schmidt, Reinhold; Seshadri, Sudha; Smith, Eric E; Sposato, Luciano A; Stephan, Blossom; Swartz, Richard H; Tzourio, Christophe; van Buchem, Mark; van der Lugt, Aad; van Oostenbrugge, Robert; Vernooij, Meike W; Viswanathan, Anand; Werring, David; Wollenweber, Frank; Wardlaw, Joanna M

2016-01-01

Brain imaging is essential for the diagnosis and characterization of cerebral small vessel disease. Several magnetic resonance imaging markers have therefore emerged, providing new information on the diagnosis, progression, and mechanisms of small vessel disease. Yet, the reproducibility of these small vessel disease markers has received little attention despite being widely used in cross-sectional and longitudinal studies. This review focuses on the main small vessel disease-related markers on magnetic resonance imaging including: white matter hyperintensities, lacunes, dilated perivascular spaces, microbleeds, and brain volume. The aim is to summarize, for each marker, what is currently known about: (1) its reproducibility in studies with a scan–rescan procedure either in single or multicenter settings; (2) the acquisition-related sources of variability; and, (3) the techniques used to minimize this variability. Based on the results, we discuss technical and other challenges that need to be overcome in order for these markers to be reliably used as outcome measures in future clinical trials. We also highlight the key points that need to be considered when designing multicenter magnetic resonance imaging studies of small vessel disease. PMID:27170700

A general purpose subroutine for fast fourier transform on a distributed memory parallel machine

NASA Technical Reports Server (NTRS)

Dubey, A.; Zubair, M.; Grosch, C. E.

1992-01-01

One issue which is central in developing a general purpose Fast Fourier Transform (FFT) subroutine on a distributed memory parallel machine is the data distribution. It is possible that different users would like to use the FFT routine with different data distributions. Thus, there is a need to design FFT schemes on distributed memory parallel machines which can support a variety of data distributions. An FFT implementation on a distributed memory parallel machine which works for a number of data distributions commonly encountered in scientific applications is presented. The problem of rearranging the data after computing the FFT is also addressed. The performance of the implementation on a distributed memory parallel machine Intel iPSC/860 is evaluated.

Parallel workflow tools to facilitate human brain MRI post-processing

PubMed Central

Cui, Zaixu; Zhao, Chenxi; Gong, Gaolang

2015-01-01

Multi-modal magnetic resonance imaging (MRI) techniques are widely applied in human brain studies. To obtain specific brain measures of interest from MRI datasets, a number of complex image post-processing steps are typically required. Parallel workflow tools have recently been developed, concatenating individual processing steps and enabling fully automated processing of raw MRI data to obtain the final results. These workflow tools are also designed to make optimal use of available computational resources and to support the parallel processing of different subjects or of independent processing steps for a single subject. Automated, parallel MRI post-processing tools can greatly facilitate relevant brain investigations and are being increasingly applied. In this review, we briefly summarize these parallel workflow tools and discuss relevant issues. PMID:26029043

High convergence efficiency design of flat Fresnel lens with large aperture

NASA Astrophysics Data System (ADS)

Ke, Jieyao; Zhao, Changming; Guan, Zhe

2018-01-01

This paper designed a circle-shaped Fresnel lens with large aperture as part of the solar pumped laser design project. The Fresnel lens designed in this paper simulate in size 1000mm×1000mm, focus length 1200mm and polymethyl methacrylate (PMMA) material in order to conduct high convergence efficiency. In the light of design requirement of concentric ring with same width of 0.3mm, this paper proposed an optimized Fresnel lens design based on previous sphere design and conduct light tracing simulation in Matlab. This paper also analyzed the effect of light spot size, light intensity distribution, optical efficiency under four conditions, monochromatic parallel light, parallel spectrum light, divergent monochromatic light and sunlight. Design by 550nm wavelength and under the condition of Fresnel reflection, the results indicated that the designed lens could convergent sunlight in diffraction limit of 11.8mm with a 78.7% optical efficiency, better than the sphere cutting design results of 30.4%.

Mechanical design of deformation compensated flexural pivots structured for linear nanopositioning stages

DOEpatents

Shu, Deming; Kearney, Steven P.; Preissner, Curt A.

2015-02-17

A method and deformation compensated flexural pivots structured for precision linear nanopositioning stages are provided. A deformation-compensated flexural linear guiding mechanism includes a basic parallel mechanism including a U-shaped member and a pair of parallel bars linked to respective pairs of I-link bars and each of the I-bars coupled by a respective pair of flexural pivots. The basic parallel mechanism includes substantially evenly distributed flexural pivots minimizing center shift dynamic errors.

Software Tools for Design and Performance Evaluation of Intelligent Systems

DTIC Science & Technology

2004-08-01

Self-calibration of Three-Legged Modular Reconfigurable Parallel Robots Based on Leg-End Distance Errors,” Robotica , Vol. 19, pp. 187-198. [4...9] Lintott, A. B., and Dunlop, G. R., “Parallel Topology Robot Calibration,” Robotica . [10] Vischer, P., and Clavel, R., “Kinematic Calibration...of the Parallel Delta Robot,” Robotica , Vol. 16, pp.207- 218, 1998. [11] Joshi, S.A., and Surianarayan, A., “Calibration of a 6-DOF Cable Robot Using

Massively Parallel Solution of Poisson Equation on Coarse Grain MIMD Architectures

NASA Technical Reports Server (NTRS)

Fijany, A.; Weinberger, D.; Roosta, R.; Gulati, S.

1998-01-01

In this paper a new algorithm, designated as Fast Invariant Imbedding algorithm, for solution of Poisson equation on vector and massively parallel MIMD architectures is presented. This algorithm achieves the same optimal computational efficiency as other Fast Poisson solvers while offering a much better structure for vector and parallel implementation. Our implementation on the Intel Delta and Paragon shows that a speedup of over two orders of magnitude can be achieved even for moderate size problems.

Timing of Surgery and Rehabilitation to Optimize Outcome for Patients with Multiple Ligament Knee Injuries: A Multicenter Clinical Trial

DTIC Science & Technology

2017-10-01

those of the author(s) and should not be construed as an official Department of the Army position, policy or decision unless so designated by other...display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE October 2017 2. REPORT TYPE Annual 3...frequently associated with concomitant injuries to nerves, vessels, tendons, cartilage and menisci. Non -operative management of MLKIs results in poor

A parallel input composite transimpedance amplifier.

PubMed

Kim, D J; Kim, C

2018-01-01

A new approach to high performance current to voltage preamplifier design is presented. The design using multiple operational amplifiers (op-amps) has a parasitic capacitance compensation network and a composite amplifier topology for fast, precision, and low noise performance. The input stage consisting of a parallel linked JFET op-amps and a high-speed bipolar junction transistor (BJT) gain stage driving the output in the composite amplifier topology, cooperating with the capacitance compensation feedback network, ensures wide bandwidth stability in the presence of input capacitance above 40 nF. The design is ideal for any two-probe measurement, including high impedance transport and scanning tunneling microscopy measurements.

A parallel input composite transimpedance amplifier

NASA Astrophysics Data System (ADS)

Kim, D. J.; Kim, C.

2018-01-01

A new approach to high performance current to voltage preamplifier design is presented. The design using multiple operational amplifiers (op-amps) has a parasitic capacitance compensation network and a composite amplifier topology for fast, precision, and low noise performance. The input stage consisting of a parallel linked JFET op-amps and a high-speed bipolar junction transistor (BJT) gain stage driving the output in the composite amplifier topology, cooperating with the capacitance compensation feedback network, ensures wide bandwidth stability in the presence of input capacitance above 40 nF. The design is ideal for any two-probe measurement, including high impedance transport and scanning tunneling microscopy measurements.

Sample size re-estimation and other midcourse adjustments with sequential parallel comparison design.

PubMed

Silverman, Rachel K; Ivanova, Anastasia

2017-01-01

Sequential parallel comparison design (SPCD) was proposed to reduce placebo response in a randomized trial with placebo comparator. Subjects are randomized between placebo and drug in stage 1 of the trial, and then, placebo non-responders are re-randomized in stage 2. Efficacy analysis includes all data from stage 1 and all placebo non-responding subjects from stage 2. This article investigates the possibility to re-estimate the sample size and adjust the design parameters, allocation proportion to placebo in stage 1 of SPCD, and weight of stage 1 data in the overall efficacy test statistic during an interim analysis.

Quadrature transmit array design using single-feed circularly polarized patch antenna for parallel transmission in MR imaging.

PubMed

Pang, Yong; Yu, Baiying; Vigneron, Daniel B; Zhang, Xiaoliang

2014-02-01

Quadrature coils are often desired in MR applications because they can improve MR sensitivity and also reduce excitation power. In this work, we propose, for the first time, a quadrature array design strategy for parallel transmission at 298 MHz using single-feed circularly polarized (CP) patch antenna technique. Each array element is a nearly square ring microstrip antenna and is fed at a point on the diagonal of the antenna to generate quadrature magnetic fields. Compared with conventional quadrature coils, the single-feed structure is much simple and compact, making the quadrature coil array design practical. Numerical simulations demonstrate that the decoupling between elements is better than -35 dB for all the elements and the RF fields are homogeneous with deep penetration and quadrature behavior in the area of interest. Bloch equation simulation is also performed to simulate the excitation procedure by using an 8-element quadrature planar patch array to demonstrate its feasibility in parallel transmission at the ultrahigh field of 7 Tesla.

Branson: A Mini-App for Studying Parallel IMC, Version 1.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Long, Alex

This code solves the gray thermal radiative transfer (TRT) equations in parallel using simple opacities and Cartesian meshes. Although Branson solves the TRT equations it is not designed to model radiation transport: Branson contains simple physics and does not have a multigroup treatment, nor can it use physical material data. The opacities have are simple polynomials in temperature there is a limited ability to specify complex geometries and sources. Branson was designed only to capture the computational demands of production IMC codes, especially in large parallel runs. It was also intended to foster collaboration with vendors, universities and other DOEmore » partners. Branson is similar in character to the neutron transport proxy-app Quicksilver from LLNL, which was recently open-sourced.« less

Method and structure for skewed block-cyclic distribution of lower-dimensional data arrays in higher-dimensional processor grids

DOEpatents

Chatterjee, Siddhartha [Yorktown Heights, NY; Gunnels, John A [Brewster, NY

2011-11-08

A method and structure of distributing elements of an array of data in a computer memory to a specific processor of a multi-dimensional mesh of parallel processors includes designating a distribution of elements of at least a portion of the array to be executed by specific processors in the multi-dimensional mesh of parallel processors. The pattern of the designating includes a cyclical repetitive pattern of the parallel processor mesh, as modified to have a skew in at least one dimension so that both a row of data in the array and a column of data in the array map to respective contiguous groupings of the processors such that a dimension of the contiguous groupings is greater than one.

Parallel Grand Canonical Monte Carlo (ParaGrandMC) Simulation Code

NASA Technical Reports Server (NTRS)

Yamakov, Vesselin I.

2016-01-01

This report provides an overview of the Parallel Grand Canonical Monte Carlo (ParaGrandMC) simulation code. This is a highly scalable parallel FORTRAN code for simulating the thermodynamic evolution of metal alloy systems at the atomic level, and predicting the thermodynamic state, phase diagram, chemical composition and mechanical properties. The code is designed to simulate multi-component alloy systems, predict solid-state phase transformations such as austenite-martensite transformations, precipitate formation, recrystallization, capillary effects at interfaces, surface absorption, etc., which can aid the design of novel metallic alloys. While the software is mainly tailored for modeling metal alloys, it can also be used for other types of solid-state systems, and to some degree for liquid or gaseous systems, including multiphase systems forming solid-liquid-gas interfaces.

Parallel Optical Random Access Memory (PORAM)

NASA Technical Reports Server (NTRS)

Alphonse, G. A.

1989-01-01

It is shown that the need to minimize component count, power and size, and to maximize packing density require a parallel optical random access memory to be designed in a two-level hierarchy: a modular level and an interconnect level. Three module designs are proposed, in the order of research and development requirements. The first uses state-of-the-art components, including individually addressed laser diode arrays, acousto-optic (AO) deflectors and magneto-optic (MO) storage medium, aimed at moderate size, moderate power, and high packing density. The next design level uses an electron-trapping (ET) medium to reduce optical power requirements. The third design uses a beam-steering grating surface emitter (GSE) array to reduce size further and minimize the number of components.

Focusing, refraction, and asymmetric transmission of elastic waves in solid metamaterials with aligned parallel gaps.

PubMed

Su, Xiaoshi; Norris, Andrew N

2016-06-01

Gradient index (GRIN), refractive, and asymmetric transmission devices for elastic waves are designed using a solid with aligned parallel gaps. The gaps are assumed to be thin so that they can be considered as parallel cracks separating elastic plate waveguides. The plates do not interact with one another directly, only at their ends where they connect to the exterior solid. To formulate the transmission and reflection coefficients for SV- and P-waves, an analytical model is established using thin plate theory that couples the waveguide modes with the waves in the exterior body. The GRIN lens is designed by varying the thickness of the plates to achieve different flexural wave speeds. The refractive effect of SV-waves is achieved by designing the slope of the edge of the plate array, and keeping the ratio between plate length and flexural wavelength fixed. The asymmetric transmission of P-waves is achieved by sending an incident P-wave at a critical angle, at which total conversion to SV-wave occurs. An array of parallel gaps perpendicular to the propagation direction of the reflected waves stop the SV-wave but let P-waves travel through. Examples of focusing, steering, and asymmetric transmission devices are discussed.

Impact of the Cancer Prevention and Control Research Network

PubMed Central

Ribisl, Kurt M.; Fernandez, Maria E.; Friedman, Daniela B.; Hannon, Peggy; Leeman, Jennifer; Moore, Alexis; Olson, Lindsay; Ory, Marcia; Risendal, Betsy; Sheble, Laura; Taylor, Vicky; Williams, Rebecca; Weiner, Bryan J.

2018-01-01

The Cancer Prevention and Control Research Network (CPCRN) is a thematic network dedicated to accelerating the adoption of evidence-based cancer prevention and control practices in communities by advancing dissemination and implementation science. Funded by the Centers for Disease Control and Prevention and National Cancer Institute, CPCRN has operated at two levels: Each participating Network Center conducts research projects with primarily local partners as well as multicenter collaborative research projects with state and national partners. Through multicenter collaboration, thematic networks leverage the expertise, resources, and partnerships of participating centers to conduct research projects collectively that might not be feasible individually. Although multicenter collaboration often is advocated, it is challenging to promote and assess. Using bibliometric network analysis and other graphical methods, this paper describes CPCRN’s multicenter publication progression from 2004 to 2014. Searching PubMed, Scopus, and Web of Science in 2014 identified 249 peer-reviewed CPCRN publications involving two or more centers out of 6,534 total. The research and public health impact of these multicenter collaborative projects initiated by CPCRN during that 10-year period were then examined. CPCRN established numerous workgroups around topics such as: 2-1-1, training and technical assistance, colorectal cancer control, federally qualified health centers, cancer survivorship, and human papillomavirus. The paper discusses the challenges that arise in promoting multicenter collaboration and the strategies that CPCRN uses to address those challenges. The lessons learned should broadly interest those seeking to promote multisite collaboration to address public health problems, such as cancer prevention and control. PMID:28215371

Design of multiple sequence alignment algorithms on parallel, distributed memory supercomputers.

PubMed

Church, Philip C; Goscinski, Andrzej; Holt, Kathryn; Inouye, Michael; Ghoting, Amol; Makarychev, Konstantin; Reumann, Matthias

2011-01-01

The challenge of comparing two or more genomes that have undergone recombination and substantial amounts of segmental loss and gain has recently been addressed for small numbers of genomes. However, datasets of hundreds of genomes are now common and their sizes will only increase in the future. Multiple sequence alignment of hundreds of genomes remains an intractable problem due to quadratic increases in compute time and memory footprint. To date, most alignment algorithms are designed for commodity clusters without parallelism. Hence, we propose the design of a multiple sequence alignment algorithm on massively parallel, distributed memory supercomputers to enable research into comparative genomics on large data sets. Following the methodology of the sequential progressiveMauve algorithm, we design data structures including sequences and sorted k-mer lists on the IBM Blue Gene/P supercomputer (BG/P). Preliminary results show that we can reduce the memory footprint so that we can potentially align over 250 bacterial genomes on a single BG/P compute node. We verify our results on a dataset of E.coli, Shigella and S.pneumoniae genomes. Our implementation returns results matching those of the original algorithm but in 1/2 the time and with 1/4 the memory footprint for scaffold building. In this study, we have laid the basis for multiple sequence alignment of large-scale datasets on a massively parallel, distributed memory supercomputer, thus enabling comparison of hundreds instead of a few genome sequences within reasonable time.

Reading through Films

ERIC Educational Resources Information Center

Raman, Madhavi Gayathri; Vijaya

2016-01-01

This paper captures the design of a comprehensive curriculum incorporating the four skills based exclusively on the use of parallel audio-visual and written texts. We discuss the use of authentic materials to teach English to Indian undergraduates aged 18 to 20 years. Specifically, we talk about the use of parallel reading (screen-play) and…

Introduction to Computers: Parallel Alternative Strategies for Students. Course No. 0200000.

ERIC Educational Resources Information Center

Chauvenne, Sherry; And Others

Parallel Alternative Strategies for Students (PASS) is a content-centered package of alternative methods and materials designed to assist secondary teachers to meet the needs of mainstreamed learning-disabled and emotionally-handicapped students of various achievement levels in the basic education content courses. This supplementary text and…

Issues of planning trajectory of parallel robots taking into account zones of singularity

NASA Astrophysics Data System (ADS)

Rybak, L. A.; Khalapyan, S. Y.; Gaponenko, E. V.

2018-03-01

A method for determining the design characteristics of a parallel robot necessary to provide specified parameters of its working space that satisfy the controllability requirement is developed. The experimental verification of the proposed method was carried out using an approximate planar 3-RPR mechanism.

Diderot: a Domain-Specific Language for Portable Parallel Scientific Visualization and Image Analysis.

PubMed

Kindlmann, Gordon; Chiw, Charisee; Seltzer, Nicholas; Samuels, Lamont; Reppy, John

2016-01-01

Many algorithms for scientific visualization and image analysis are rooted in the world of continuous scalar, vector, and tensor fields, but are programmed in low-level languages and libraries that obscure their mathematical foundations. Diderot is a parallel domain-specific language that is designed to bridge this semantic gap by providing the programmer with a high-level, mathematical programming notation that allows direct expression of mathematical concepts in code. Furthermore, Diderot provides parallel performance that takes advantage of modern multicore processors and GPUs. The high-level notation allows a concise and natural expression of the algorithms and the parallelism allows efficient execution on real-world datasets.

A mirror for lab-based quasi-monochromatic parallel x-rays

NASA Astrophysics Data System (ADS)

Nguyen, Thanhhai; Lu, Xun; Lee, Chang Jun; Jung, Jin-Ho; Jin, Gye-Hwan; Kim, Sung Youb; Jeon, Insu

2014-09-01

A multilayered parabolic mirror with six W/Al bilayers was designed and fabricated to generate monochromatic parallel x-rays using a lab-based x-ray source. Using this mirror, curved bright bands were obtained in x-ray images as reflected x-rays. The parallelism of the reflected x-rays was investigated using the shape of the bands. The intensity and monochromatic characteristics of the reflected x-rays were evaluated through measurements of the x-ray spectra in the band. High intensity, nearly monochromatic, and parallel x-rays, which can be used for high resolution x-ray microscopes and local radiation therapy systems, were obtained.

Parallel-vector computation for linear structural analysis and non-linear unconstrained optimization problems

NASA Technical Reports Server (NTRS)

Nguyen, D. T.; Al-Nasra, M.; Zhang, Y.; Baddourah, M. A.; Agarwal, T. K.; Storaasli, O. O.; Carmona, E. A.

1991-01-01

Several parallel-vector computational improvements to the unconstrained optimization procedure are described which speed up the structural analysis-synthesis process. A fast parallel-vector Choleski-based equation solver, pvsolve, is incorporated into the well-known SAP-4 general-purpose finite-element code. The new code, denoted PV-SAP, is tested for static structural analysis. Initial results on a four processor CRAY 2 show that using pvsolve reduces the equation solution time by a factor of 14-16 over the original SAP-4 code. In addition, parallel-vector procedures for the Golden Block Search technique and the BFGS method are developed and tested for nonlinear unconstrained optimization. A parallel version of an iterative solver and the pvsolve direct solver are incorporated into the BFGS method. Preliminary results on nonlinear unconstrained optimization test problems, using pvsolve in the analysis, show excellent parallel-vector performance indicating that these parallel-vector algorithms can be used in a new generation of finite-element based structural design/analysis-synthesis codes.

A parallel algorithm for the two-dimensional time fractional diffusion equation with implicit difference method.

PubMed

Gong, Chunye; Bao, Weimin; Tang, Guojian; Jiang, Yuewen; Liu, Jie

2014-01-01

It is very time consuming to solve fractional differential equations. The computational complexity of two-dimensional fractional differential equation (2D-TFDE) with iterative implicit finite difference method is O(M(x)M(y)N(2)). In this paper, we present a parallel algorithm for 2D-TFDE and give an in-depth discussion about this algorithm. A task distribution model and data layout with virtual boundary are designed for this parallel algorithm. The experimental results show that the parallel algorithm compares well with the exact solution. The parallel algorithm on single Intel Xeon X5540 CPU runs 3.16-4.17 times faster than the serial algorithm on single CPU core. The parallel efficiency of 81 processes is up to 88.24% compared with 9 processes on a distributed memory cluster system. We do think that the parallel computing technology will become a very basic method for the computational intensive fractional applications in the near future.

Effects of imbalanced currents on large-format LiFePO4/graphite batteries systems connected in parallel

NASA Astrophysics Data System (ADS)

Shi, Wei; Hu, Xiaosong; Jin, Chao; Jiang, Jiuchun; Zhang, Yanru; Yip, Tony

2016-05-01

With the development and popularization of electric vehicles, it is urgent and necessary to develop effective management and diagnosis technology for battery systems. In this work, we design a parallel battery model, according to equivalent circuits of parallel voltage and branch current, to study effects of imbalanced currents on parallel large-format LiFePO4/graphite battery systems. Taking a 60 Ah LiFePO4/graphite battery system manufactured by ATL (Amperex Technology Limited, China) as an example, causes of imbalanced currents in the parallel connection are analyzed using our model, and the associated effect mechanisms on long-term stability of each single battery are examined. Theoretical and experimental results show that continuously increasing imbalanced currents during cycling are mainly responsible for the capacity fade of LiFePO4/graphite parallel batteries. It is thus a good way to avoid fast performance fade of parallel battery systems by suppressing variations of branch currents.

A parallel variable metric optimization algorithm

NASA Technical Reports Server (NTRS)

Straeter, T. A.

1973-01-01

An algorithm, designed to exploit the parallel computing or vector streaming (pipeline) capabilities of computers is presented. When p is the degree of parallelism, then one cycle of the parallel variable metric algorithm is defined as follows: first, the function and its gradient are computed in parallel at p different values of the independent variable; then the metric is modified by p rank-one corrections; and finally, a single univariant minimization is carried out in the Newton-like direction. Several properties of this algorithm are established. The convergence of the iterates to the solution is proved for a quadratic functional on a real separable Hilbert space. For a finite-dimensional space the convergence is in one cycle when p equals the dimension of the space. Results of numerical experiments indicate that the new algorithm will exploit parallel or pipeline computing capabilities to effect faster convergence than serial techniques.

A new parallel-vector finite element analysis software on distributed-memory computers

NASA Technical Reports Server (NTRS)

Qin, Jiangning; Nguyen, Duc T.

1993-01-01

A new parallel-vector finite element analysis software package MPFEA (Massively Parallel-vector Finite Element Analysis) is developed for large-scale structural analysis on massively parallel computers with distributed-memory. MPFEA is designed for parallel generation and assembly of the global finite element stiffness matrices as well as parallel solution of the simultaneous linear equations, since these are often the major time-consuming parts of a finite element analysis. Block-skyline storage scheme along with vector-unrolling techniques are used to enhance the vector performance. Communications among processors are carried out concurrently with arithmetic operations to reduce the total execution time. Numerical results on the Intel iPSC/860 computers (such as the Intel Gamma with 128 processors and the Intel Touchstone Delta with 512 processors) are presented, including an aircraft structure and some very large truss structures, to demonstrate the efficiency and accuracy of MPFEA.

High order parallel numerical schemes for solving incompressible flows

NASA Technical Reports Server (NTRS)

Lin, Avi; Milner, Edward J.; Liou, May-Fun; Belch, Richard A.

1992-01-01

The use of parallel computers for numerically solving flow fields has gained much importance in recent years. This paper introduces a new high order numerical scheme for computational fluid dynamics (CFD) specifically designed for parallel computational environments. A distributed MIMD system gives the flexibility of treating different elements of the governing equations with totally different numerical schemes in different regions of the flow field. The parallel decomposition of the governing operator to be solved is the primary parallel split. The primary parallel split was studied using a hypercube like architecture having clusters of shared memory processors at each node. The approach is demonstrated using examples of simple steady state incompressible flows. Future studies should investigate the secondary split because, depending on the numerical scheme that each of the processors applies and the nature of the flow in the specific subdomain, it may be possible for a processor to seek better, or higher order, schemes for its particular subcase.

Design and realization of test system for testing parallelism and jumpiness of optical axis of photoelectric equipment

NASA Astrophysics Data System (ADS)

Shi, Sheng-bing; Chen, Zhen-xing; Qin, Shao-gang; Song, Chun-yan; Jiang, Yun-hong

2014-09-01

With the development of science and technology, photoelectric equipment comprises visible system, infrared system, laser system and so on, integration, information and complication are higher than past. Parallelism and jumpiness of optical axis are important performance of photoelectric equipment,directly affect aim, ranging, orientation and so on. Jumpiness of optical axis directly affect hit precision of accurate point damage weapon, but we lack the facility which is used for testing this performance. In this paper, test system which is used fo testing parallelism and jumpiness of optical axis is devised, accurate aim isn't necessary and data processing are digital in the course of testing parallelism, it can finish directly testing parallelism of multi-axes, aim axis and laser emission axis, parallelism of laser emission axis and laser receiving axis and first acuualizes jumpiness of optical axis of optical sighting device, it's a universal test system.