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Sample records for bundle-branch block

  1. Right bundle branch block

    DEFF Research Database (Denmark)

    Bussink, Barbara E; Holst, Anders Gaarsdal; Jespersen, Lasse;

    2013-01-01

    AimsTo determine the prevalence, predictors of newly acquired, and the prognostic value of right bundle branch block (RBBB) and incomplete RBBB (IRBBB) on a resting 12-lead electrocardiogram in men and women from the general population.Methods and resultsWe followed 18 441 participants included.......5%/2.3% in women, P Right bundle branch block was associated with significantly.......60-1.62). The presence of IRBBB was not associated with any adverse outcome.ConclusionIn this cohort study, RBBB and IRBBB were two to three times more common among men than women. Right bundle branch block was associated with increased cardiovascular risk and all-cause mortality, whereas IRBBB was not. Contrary...

  2. Left bundle-branch block

    DEFF Research Database (Denmark)

    Risum, Niels; Strauss, David; Sogaard, Peter;

    2013-01-01

    The relationship between myocardial electrical activation by electrocardiogram (ECG) and mechanical contraction by echocardiography in left bundle-branch block (LBBB) has never been clearly demonstrated. New strict criteria for LBBB based on a fundamental understanding of physiology have recently...

  3. [Bundle-branch block depending on the heart rate].

    Science.gov (United States)

    Apostolov, L

    1975-01-01

    Five patients are reported, admitted to the hospital, with diseases predominantly of the cardio-vascular system. During the electrocardiographic examinations bundle branch block was established, depending on heart rate. It fluctuated within the physiological limits from 50 to 90/min. In three of the patients, the bundle branch block appeared with the quickening of the heart rate (tachycardia-depending bundle branch block) and in two of the patients--the bundle branch block appeared during the slowing down of the heart action and disappeared with its quickening (bradicardia-depending bundle branch block). A brief literature review is presented and attention is paid to the possible diagnostic errors and the treatment mode of those patients with cardiac tonic and antiarrhythmic medicaments.

  4. Lesson Eleven Transient and intermittent left bundle branch block

    Institute of Scientific and Technical Information of China (English)

    鲁端; 王劲

    2004-01-01

    @@ In transient left bundle branch block,normal intraventricular conduction subsequently returns,if only1temporarily.The condition has also been called paroxysmal,unstable,or temporary left bundle branch block. Its etiology is similar to that of the stable variety2, with the great majority of the patients having ischemic or hypertensive heart disease or both. Transient bundle branch block may complicate acute myocardial infarction or may occur during attacks of angina. It may appear during an episode of congestive heart failure and disappear with improvement of the cardiac status. Most patients eventually develop permanent block. Occasionally,however, the patient may revert to normal conduction even years after consistently demonstrating the block.

  5. MYOCARDIAL DEFORMATION AND COMPLETE LEFT BUNDLE BRANCH BLOCK

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    E. N. Pavlyukova

    2015-12-01

    Full Text Available Tissue Doppler imaging is evolving as a useful echocardiographic tool for quantitative assessment of left ventricular systolic and diastolic function. Over the last 10 years, myocardial deformation imaging has become possible initially with tissue Doppler , and more recently with myocardial speckle-tracking using 2D echocardiography. Unlike simple tissue velocity measurements, deformation measurements are specific for the region of interest. Strain rate or strain measurements have been used as sensitive indicators for subclinical diseases, and it is the most widely used tool to assess mechanical dyssynchrony. Left bundle branch block is a frequent, etiologically heterogeneous, clinically hostile and diagnostically challenging entity. About 2% of patients underwent cardiac stress testing show stable or intermittent left bundle branch block. Presence of left bundle branch block is associated with a lower and slower diastolic coronary flow velocity especially during hyperemia. Stress echocardiography is the best option for the diagnosis of ischemic heart disease, albeit specificity and sensitivity reduce in patients with left bundle branch block in the territory of left anterior descending artery in presence of initial septum dyskinesia.

  6. Cardiac pacing in left bundle branch/ bifascicular block patients

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    Maddali Madan

    2010-01-01

    Full Text Available The primary concern in patients with bifascicular block is the increased risk of progression to complete heart block. Further, an additional first-degree A-V block in patients with bifascicular block or LBBB might increase the risk of block progression. Anesthesia, monitoring and surgical techniques can induce conduction defects and bradyarrhythmias in patients with pre-existing bundle branch block. In the setting of an acute MI, several different types of conduction disturbance may become manifest and complete heart block occurs usually in patients with acute myocardial infarction more commonly if there is pre-existing or new bundle branch block. The question that arises is whether it is necessary to insert a temporary pacing catheter in patients with bifascicular block undergoing anesthesia. It is important that an anesthesiologist should be aware of the indications for temporary cardiac pacing as well as the current recommendations for permanent pacing in patients with chronic bifascicular and trifascicular block. This article also highlights the recent guidelines for temporary transvenous pacing in the setting of acute MI and the different pacing modalities that are available for an anesthesiologist.

  7. Left bundle branch block: a rare ECG manifestation of hyperkalemia

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    Venkata Madhav M

    2015-04-01

    Full Text Available A 20-year-old female patient with chronic kidney disease was brought to our emergency medical department with symptoms of pain in chest and abdomen, vomitings. Laboratory testing revealed serum potassium 7.7 mEq/L, serum creatinine 9.1 mg/dL. Electrocardiogram (ECG showed left bundle branch block (LBBB pattern with left axis deviation, tall T waves and ST elevation. Among ECG alterations in hyperkalemia, LBBB is rare and is being reported in our case.

  8. [Unstable angina pectoris in intermittent left bundle branch block].

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    Albert, S; Flury, G

    1997-11-19

    We present a case report of a 57 year old woman with recurrent chest pain, initially exclusively at exercise and later also at rest. This led to an emergency hospitalization for suspected myocardial infarction. As there were no enzymatic and electrocardiographic signs of acute infarction she was treated, as unstable angina pectoris. Coronary angiography revealed but a modest coronary atheromatosis without significant coronary stenosis. Therefore her symptoms were interpreted as primary manifestation of an intermittant Left Bundle Branch Block (LBBB) with changing heart-rate dependency. A majority of patients with LBBB and chest pain have a relevant Coronary Artery Disease (CAD). There is a small number of reports in literature about patients with intermittant LBBB without significant CAD but with both typical (exercise-induced) and atypical (at rest) chest pain. Special features of our case are presentation of LBBB as unstable angina, documentation of an intermittant LBBB with changing heart-rate dependency and heart-rate-dependent supranormal conduction in the left bundle branch. We review some important aspects of LBBB with regard to this case.

  9. Is It Complete Left Bundle Branch Block? Just Ablate the Right Bundle.

    Science.gov (United States)

    Ali, Hussam; Lupo, Pierpaolo; Foresti, Sara; De Ambroggi, Guido; Epicoco, Gianluca; Fundaliotis, Angelica; Cappato, Riccardo

    2017-03-01

    Complete left bundle branch block (LBBB) is established according to standard electrocardiographic criteria. However, functional LBBB may be rate-dependent or can perpetuate during tachycardia due to repetitive concealed retrograde penetration of impulses through the contralateral bundle "linking phenomenon." In this brief article, we present two patients with basal complete LBBB in whom ablating the right bundle unmasked the actual antegrade conduction capabilities of the left bundle. These cases highlight intriguing overlap between electrophysiological concepts of complete block, linking, extremely slow, and concealed conduction.

  10. Role of electrophysiological study in patients with syncope and bundle branch block

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    Neshat Nazari

    2014-01-01

    Full Text Available Background: The finding of bundle branch block (BBB in patients with syncope suggests that paroxysmal atrioventricular block (AVB or ventricular tachyarrhythmia (VT may be the cause of syncope. Guidelines for cardiac pacing and cardiac resynchronization therapy have been recommended to perform electrophysiological study (EPS for confirming main cause of syncope. Therefore, the aim of our study was to evaluate the role of EPS in patients with syncope and BBB. Materials and Methods: We evaluated 133 patients (mean age 63 ± 13.8 years with past history of syncope and BBB from April 2002 to December 2010 who referred to Arrhythmia clinic in two tertiary care centers. All patients underwent EPS on admission time. The frequency distributions of AVB and VT in patients were determined. Results: Left bundle branch block was diagnosed in 184 (82.1% patients. 133 of them had preserved left ventricular ejection fraction (LVEF ≥45% that in 91 (68.4% of those, EPS finding was normal. In 41 (30.8% patients AVB was reported. In 2 (1.5% patients VT and atrioventricular nodal reentrant tachycardia were seen. Coronary artery disease was more common in patients with AVB and abnormal EPS finding (P = 0.02. Conclusion: Ventricular tachyarrhythmia was a rare electrophysiological finding in those with syncope, bifascicular block, and preserved LVEF. Considering cost-effect benefit, pacemaker or implantable loop recorder implantation is suggested; however, EPS may not be necessary to perform before permanent pacemaker implantation.

  11. Hybrid Bacterial Foraging and Particle Swarm Optimization for detecting Bundle Branch Block.

    Science.gov (United States)

    Kora, Padmavathi; Kalva, Sri Ramakrishna

    2015-01-01

    Abnormal cardiac beat identification is a key process in the detection of heart diseases. Our present study describes a procedure for the detection of left and right bundle branch block (LBBB and RBBB) Electrocardiogram (ECG) patterns. The electrical impulses that control the cardiac beat face difficulty in moving inside the heart. This problem is termed as bundle branch block (BBB). BBB makes it harder for the heart to pump blood effectively through the heart circulatory system. ECG feature extraction is a key process in detecting heart ailments. Our present study comes up with a hybrid method combining two heuristic optimization methods: Bacterial Forging Optimization (BFO) and Particle Swarm Optimization (PSO) for the feature selection of ECG signals. One of the major controlling forces of BFO algorithm is the chemotactic movement of a bacterium that models a test solution. The chemotaxis process of the BFO depends on random search directions which may lead to a delay in achieving the global optimum solution. The hybrid technique: Bacterial Forging-Particle Swarm Optimization (BFPSO) incorporates the concepts from BFO and PSO and it creates individuals in a new generation. This BFPSO method performs local search through the chemotactic movement of BFO and the global search over the entire search domain is accomplished by a PSO operator. The BFPSO feature values are given as the input for the Levenberg-Marquardt Neural Network classifier.

  12. Heart Failure with Transient Left Bundle Branch Block in the Setting of Left Coronary Fistula

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    Stephen P. Juraschek

    2011-01-01

    Full Text Available Coronary arterial fistulas are rare communications between vessels or chambers of the heart. Although cardiac symptoms associated with fistulas are well described, fistulas are seldom considered in the differential diagnosis of acute myocardial ischemia. We describe the case of a 64-year-old man who presented with left shoulder pain, signs of heart failure, and a new left bundle branch block (LBBB. Cardiac catheterization revealed a small left anterior descending (LAD-to-pulmonary artery (PA fistula. Diuresis led to subjective improvement of the patient's symptoms and within several days the LBBB resolved. We hypothesize that the coronary fistula in this patient contributed to transient ischemia of the LAD territory through a coronary steal mechanism. We elected to observe rather than repair the fistula, as his symptoms and ECG changes resolved with treatment of his heart failure.

  13. Left bundle-branch block--pathophysiology, prognosis, and clinical management.

    Science.gov (United States)

    Francia, Pietro; Balla, Cristina; Paneni, Francesco; Volpe, Massimo

    2007-03-01

    Given its broad use as a screening tool, the electrocardiogram (ECG) has largely become one of the most common diagnostic tests performed in routine clinical practice. As a result, the finding of left bundle-branch block (LBBB) in the absence of a well-defined clinical setting has become relatively frequent and raises questions and often concerns. While in the absence of clinically detectable heart disease LBBB does not necessarily imply poor outcomes, physicians should be aware of the role of LBBB in stratifying risk of cardiovascular events and death in subjects with both ischemic and nonischemic heart disease. This paper reviews historical landmarks, pathophysiologic features, prognostic implications, and clinical management of LBBB in apparently healthy subjects and those with heart disease.

  14. Detection of Bundle Branch Block using Adaptive Bacterial Foraging Optimization and Neural Network

    Directory of Open Access Journals (Sweden)

    Padmavthi Kora

    2017-03-01

    Full Text Available The medical practitioners analyze the electrical activity of the human heart so as to predict various ailments by studying the data collected from the Electrocardiogram (ECG. A Bundle Branch Block (BBB is a type of heart disease which occurs when there is an obstruction along the pathway of an electrical impulse. This abnormality makes the heart beat irregular as there is an obstruction in the branches of heart, this results in pulses to travel slower than the usual. Our current study involved is to diagnose this heart problem using Adaptive Bacterial Foraging Optimization (ABFO Algorithm. The Data collected from MIT/BIH arrhythmia BBB database applied to an ABFO Algorithm for obtaining best(important feature from each ECG beat. These features later fed to Levenberg Marquardt Neural Network (LMNN based classifier. The results show the proposed classification using ABFO is better than some recent algorithms reported in the literature.

  15. Prognostic significance of right bundle branch block in patients with acute inferior myocardial infarction

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    Iwasaki,Jun

    2009-02-01

    Full Text Available

    There is little information available concerning the influence of right bundle branch block (RBBB on the prognosis of patients with inferior myocardial infarction (MI. In this study we evaluated the influence of RBBB on the short-term prognosis of patients with inferior MI. Our study subjects were 1,265 hospitalized patients with Q wave MI. Patients were divided into 4 groups based on the presence or absence of RBBB and on the location of the infarction. RBBB was classified into 4 categories according to the timing of its appearance and its duration as new permanent, transient, old and age indeterminate. In-hospital death and pulmonary congestion were observed more frequently in patients with RBBB than in those without RBBB. Moreover, in inferior MI as in anterior MI, in-hospital death and pulmonary congestion occurred more frequently in new permanent RBBB patients than in patients with other types of RBBB. Multivariate regression analysis reveals that new permanent RBBB was a strong independent predictor for an adverse short-term prognosis in patients with inferior MI, as well as in patients with anterior MI. New permanent RBBB during inferior MI is a strong independent predictor for increased in-hospital mortality, regardless of the infarction location.

  16. Myocardial blood flow assessment with {sup 82}rubidium-PET imaging in patients with left bundle branch block

    Energy Technology Data Exchange (ETDEWEB)

    Falcao, Andrea; Chalela, William; Giorgi, Maria Clementina; Imada, Rodrigo; Soares Junior, Jose; Do Val, Renata; Oliveira, Marco Antonio; Izaki, Marisa; Kalil Filho, Roberto; Meneghetti, Jose C., E-mail: andrea.falcao@incor.usp.br [Universidade de Sao Paulo (InCor/USP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Instituto do Coracao

    2015-11-15

    Objectives: Perfusion abnormalities are frequently seen in Single Photon Emission Computed Tomography (SPECT) when a left bundle branch block is present. A few studies have shown decreased coronary flow reserve in the left anterior descending territory, regardless of the presence of coronary artery disease. Objective: we sought to investigate rubidium-82 ({sup 82}Rb) positron emission tomography imaging in the assessment of myocardial blood flow and coronary flow reserve in patients with left bundle branch block. Methods: thirty-eight patients with left bundle branch block (GI), median age 63.5 years, 22 (58%) female, 12 with coronary artery disease (≥70%; GI-A) and 26 with no evidence of significant coronary artery disease (GI-B), underwent rest-dipyridamole stress {sup 82}Rb-positron emission tomography with absolute quantitative flow measurements using Cedars-Sinai software (mL/min/g). The relative myocardial perfusion and left ventricular ejection fraction were assessed in 17 segments. These parameters were compared with those obtained from 30 patients with normal {sup 82}Rb-positron emission tomography studies and without left bundle branch block (GII). Results: stress myocardial blood flow and coronary flow reserve were significantly lower in GI than in GII (p>0.05). The comparison of coronary flow reserve between GI-A and GI-B showed that it was different from the global coronary flow reserve (p<0.05) and the stress flow was significantly lower in the anterior than in the septal wall for both groups. Perfusion abnormalities were more prevalent in GI-A (p=0.06) and the left ventricular ejection fraction was not different between GI-A and GI-B, whereas it was lower in GI than in GII (p<0.001). Conclusion: the data confirm that patients with left bundle branch block had decreased myocardial blood flow and coronary flow reserve and coronary flow reserve assessed by {sup 82}Rb-positron emission tomography imaging may be useful in identifying coronary artery

  17. Circumferential myocardial strain in cardiomyopathy with and without left bundle branch block

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    Zimetbaum Peter J

    2010-01-01

    Full Text Available Abstract Background Cardiac resynchronization therapy (CRT has been shown to decrease mortality in 60-70% of advanced heart failure patients with left bundle branch block (LBBB and QRS duration > 120 ms. There have been intense efforts to find reproducible non-invasive parameters to predict CRT response. We hypothesized that different left ventricular contraction patterns may exist in LBBB patients with depressed systolic function and applied tagged cardiovascular magnetic resonance (CMR to assess circumferential strain in this population. Methods We determined myocardial circumferential strain at the basal, mid, and apical ventricular level in 35 subjects (10 with ischemic cardiomyopathy, 15 with non-ischemic cardiomyopathy, and 10 healthy controls. Patterns of circumferential strain were analyzed. Time to peak systolic circumferential strain in each of the 6 segments in all three ventricular slices and the standard deviation of time to peak strain in the basal and mid ventricular slices were determined. Results Dyskinesis of the anterior septum and the inferior septum in at least two ventricular levels was seen in 50% (5 out of 10 of LBBB patients while 30% had isolated dyskinesis of the anteroseptum, and 20% had no dyskinesis in any segments, similar to all of the non-LBBB patients and healthy controls. Peak circumferential strain shortening was significantly reduced in all cardiomyopathy patients at the mid-ventricular level (LBBB 9 ± 6%, non-LBBB 10 ± 4% vs. healthy 19 ± 4%; both p Conclusions Septal dyskinesis exists in some patients with LBBB. Myocardial circumferential strain analysis enables detailed characterization of contraction patterns, strengths, and timing in cardiomyopathy patients with and without LBBB.

  18. Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block

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    Estêvan Vieira Cabeda

    2015-01-01

    Full Text Available AbstractBackground:Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB.Objective:To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA (stenosis ≥ 70% as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA and compare the results with those of single photon emission computed tomography (SPECT myocardial perfusion scintigraphy.Methods:Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography. Independent examiners performed per-patient and per-coronary territory assessments. All patients gave written informed consent to participate in the study that was approved by the institution’s ethics committee.Results:The patients’ mean age was 62 ± 10 years. The mean dose of radiation for the tomography protocol was 9.3 ± 4.6 mSv. With regard to CTP, the per-patient values for sensitivity, specificity, positive and negative predictive values, and accuracy were 86%, 81%, 80%, 87%, and 83%, respectively (p = 0.001. The per-territory values were 63%, 86%, 65%, 84%, and 79%, respectively (p < 0.001. In both analyses, the addition of CTP to CTA achieved higher diagnostic accuracy for detecting myocardial ischemia than SPECT (p < 0.001.Conclusion:The use of the stress tomography protocol is feasible and has good diagnostic accuracy for assessing myocardial ischemia in patients with LBBB.

  19. Usefulness of Dipyridamole Myocardial Perfusion SPECT in Patients with Left Bundle Branch Block

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    Naser Aslanabadi

    2006-08-01

    Full Text Available Background: Diagnosis of coronary artery disease (CAD in patients with left bundle branch block (LBBB is considered as a challenge in cardiology due to the low accuracy of noninvasive methods such as basal and stress electrocardiography (ECG. This diagnostic challenge can be reduced but not eliminated using dipyridamole as a stress method instead of exercise. The aim of this study was to assess the diagnostic value of dipyridamole stress Tc-99m Sestamibi single photon emission computed tomography (SPECT myocardial perfusion imaging in patients with complete LBBB. Methods: We studied 40 patients with permanent and complete LBBB using Tc-99m Sestamibi SPECT and dipyridamole stress to evaluate CAD. Perfusion defect was considered fixed when there was no difference between rest and stress score, while reversible defect was defined as a segment with higher score on stress images. All patients underwent coronary angiography. Results: Eleven patients (27.5% had normal myocardial perfusion SPECT and 29 patients (72.5% had reversible perfusion defects. Angiography was positive in 30 patients, while 10 cases showed normal angiography. The sensitivity, specificity, positive predict value and negative predict value of our study for detecting >50% coronary stenosis was 86.6%, 70%, 89% and 64% respectively. Conclusion: We found 33 (82.5% patients with concordant angiography and myocardial perfusion SPECT results (p=0.002. Angiography was positive in 90% of patients with reversible perfusion defects on myocardial perfusion SPECT. In summary, Tc-99m Sestamibi SPECT in patients with LBBB showed high accuracy (82.5% in detecting >50% coronary stenosis.

  20. Exercise Induced Left Bundle Branch Block Treated with Cardiac Rehabilitation: A Case Report and a Review of the Literature

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    Nathan S. Anderson

    2014-01-01

    Full Text Available Exercise induced bundle branch block is a rare observation in exercise testing, accounting for 0.5 percent of exercise tests. The best treatment of this condition and its association with coronary disease remain unclear. We describe a case associated with normal coronary arteries which was successfully treated with exercise training. While this treatment has been used previously, our case has a longer followup than previously reported and demonstrates that the treatment is not durable in the absence of continued exercise.

  1. Intermittent Left Bundle Branch Block and Myocardial Ischemia in Patient Without Coronary Artery Stenosis: A Case Report

    Institute of Scientific and Technical Information of China (English)

    Ju-fang CHI; Hang-yuan GUO; Long-bin LIU

    2009-01-01

    @@ Left bundle branch block (LBBB), traditionally viewed as an electrophysiologic abnormality, is increas-ingly recognized for its effects on hemodynamics and patient's prognosis[1]. Exercise nuclear studies frequently show reversible perfusion defects in the absence of ob-structive coronary artery disease[2] and some patients with intermittent LBBB develop angina coincident with the onset of LBBB[3]. We report a case of intermittent LBBB with abnormal stress technetium 99mTc single-pho-ton emission computed tomography (SPECT) study and normal coronary artery angiography.

  2. Intermittent bundle-branch block in patients with accessory atrio-His or atrio-AV nodal pathways. Variants of the Lown-Ganong-Levine syndrome.

    Science.gov (United States)

    Befeler, B; Castellanos, A; Aranda, J; Gutierrez, R; Lazzara, R

    1976-02-01

    Intracardiac electrophysiological studies were performed in two patients with a documented history of repetitive supraventricular tachyarrhythmias. Case 1, with short PR interval and narrow QRS complexes had a short AH interval and intermittent right bundle-branch block. Thus the short PR wide QRS syndrome is not always a result of the Wolff-Parkinson-White syndrome but can also be seen in the Lown-Ganong-Levine syndrome coexisting with bundle-branch block. Case 2, with normal PR and AH at the lower limits of normal, showed the dual pathway response to atrial pacing that can occur in patients with Lown-Ganong-Levine syndrome. He also had tachycardia-dependent right bundle-branch block and left posterior hemiblock. Therefore, neither the short PR interval nor the narrow QRS complexes characterized these forms of pre-excitation. The constant features were, from the clinical viewpoint, the occurrence of repetitive supraventricular tachyarrhythmias, and electrophysiologically the abnormal response to atrial stimulation.

  3. Relation of QRS Duration to Clinical Benefit of Cardiac Resynchronization Therapy in Mild Heart Failure Patients Without Left Bundle Branch Block

    DEFF Research Database (Denmark)

    Biton, Yitschak; Kutyifa, Valentina; Cygankiewicz, Iwona

    2016-01-01

    BACKGROUND: There are conflicting data regarding the efficacy of cardiac resynchronization therapy (CRT) in patients with heart failure (HF) and without left bundle branch block. METHODS AND RESULTS: We evaluated the long-term clinical outcomes of 537 non-left bundle branch block patients with mi...... shorter QRS was associated with a significantly increased risk with CRT-D relative to implantable cardioverter-defibrillator -only. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifiers: NCT00180271, NCT01294449, and NCT02060110....

  4. Left ventricular performance during triggered left ventricular pacing in patients with cardiac resynchronization therapy and left bundle branch block

    DEFF Research Database (Denmark)

    Witt, Christoffer Tobias; Kronborg, Mads Brix; Nohr, Ellen Aagaard;

    2016-01-01

    PURPOSE: To assess the acute effect of triggered left ventricular pacing (tLVp) on left ventricular performance and contraction pattern in patients with heart failure, left bundle branch block (LBBB), and cardiac resynchronization therapy (CRT). METHODS: Twenty-three patients with pre-implant QRS...... conduction, tLVp, and BiV pacing and compared as paired data. Echocardiographic analysis was done blinded with respect to pacing mode. RESULTS: LVEF was significantly higher during BiV pacing (47 ± 11 %) compared with intrinsic conduction (43 ± 13 %, P = 0.001) and tLVp (44 ± 13 %, P = 0.001), while......V pacing. CONCLUSIONS: The acute effect of tLVp on LV systolic function and contraction pattern is significantly lower than the effect of BiV pacing and not different from intrinsic conduction in patients with LBBB and CRT....

  5. Mechanical analysis of congestive heart failure caused by bundle branch block based on an electromechanical canine heart model

    Science.gov (United States)

    Dou, Jianhong; Xia, Ling; Zhang, Yu; Shou, Guofa; Wei, Qing; Liu, Feng; Crozier, Stuart

    2009-01-01

    Asynchronous electrical activation, induced by bundle branch block (BBB), can cause reduced ventricular function. However, the effects of BBB on the mechanical function of heart are difficult to assess experimentally. Many heart models have been developed to investigate cardiac properties during BBB but have mainly focused on the electrophysiological properties. To date, the mechanical function of BBB has not been well investigated. Based on a three-dimensional electromechanical canine heart model, the mechanical properties of complete left and right bundle branch block (LBBB and RBBB) were simulated. The anatomical model as well as the fiber orientations of a dog heart was reconstructed from magnetic resonance imaging (MRI) and diffusion tensor MRI (DT-MRI). Using the solutions of reaction-diffusion equations and with a strategy of parallel computation, the asynchronous excitation propagation and intraventricular conduction in BBB was simulated. The mechanics of myocardial tissues were computed with time-, sarcomere length-dependent uniaxial active stress initiated at the time of depolarization. The quantification of mechanical intra- and interventricular asynchrony of BBB was then investigated using the finite-element method with an eight-node isoparametric element. The simulation results show that (1) there exists inter- and intraventricular systolic dyssynchrony during BBB; (2) RBBB may have more mechanical synchrony and better systolic function of the left ventricle (LV) than LBBB; (3) the ventricles always move toward the early-activated ventricle; and (4) the septum experiences higher stress than left and right ventricular free walls in BBB. The simulation results validate clinical and experimental recordings of heart deformation and provide regional quantitative estimates of ventricular wall strain and stress. The present work suggests that an electromechanical heart model, incorporating real geometry and fiber orientations, may be helpful for better

  6. Diagnosis and outcome in a prehospital cohort of patients with bundle branch block and suspected acute myocardial infarction

    Science.gov (United States)

    Stengaard, Carsten; Sørensen, Christina Ankjær; Thygesen, Kristian; Bøtker, Hans Erik; Thuesen, Leif; Terkelsen, Christian Juhl

    2013-01-01

    Background: Immediate revascularization is beneficial in patients with presumed new-onset bundle branch block myocardial infarction (BBBMI). In the prehospital setting, it is a challenge to diagnose new-onset BBBMI and triage accordingly. Methods: ECG, final diagnosis, and mortality were assessed in a prehospital cohort of 4905 consecutive patients with suspected acute myocardial infarction (AMI). Bundle branch block (BBB) was defined as QRS duration ≥120 ms caused by delayed intraventricular conduction. Mortality and angiography data were obtained from the Central Office of Civil Registration and the Western Denmark Heart Registry. Definite diagnosis of AMI and the onset of BBB were determined by expert consensus. Patients were divided into four groups: with or without AMI and with or without BBB. Mortality was evaluated by Kaplan–Meier plots and compared using log-rank statistics. Results: AMI was diagnosed in 954 patients, of whom 118 had BBB. In 3951 patients without AMI, 436 had BBB. Patients with BBBMI were less often revascularized than patients with AMI without BBB (24 vs. 54%, p<0.001). BBBMI was categorized as new onset in 43 patients of whom two were triaged for acute angioplasty. One-year mortality was 47.2, 17.5, 20.8, and 8.6% (log-rank <0.001) in patients with BBBMI, patients with AMI without BBB, patients with BBB without AMI, and patients without AMI or BBB, respectively. Conclusions: Patients with BBBMI have a high mortality. Less than 25% undergo revascularization and only very few patients with new-onset BBBMI are transferred for urgent revascularization. Focus on improving triage and prehospital identification of high-risk patients with BBB and chest pain could improve outcome. PMID:24222828

  7. Mechanical analysis of congestive heart failure caused by bundle branch block based on an electromechanical canine heart model

    Energy Technology Data Exchange (ETDEWEB)

    Dou Jianhong; Xia Ling; Zhang Yu; Shou Guofa [Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027 (China); Wei Qing; Liu Feng; Crozier, Stuart [School of Information Technology and Electrical Engineering, University of Queensland, St Lucia, Brisbane, Queensland 4072 (Australia)], E-mail: xialing@zju.edu.cn

    2009-01-21

    Asynchronous electrical activation, induced by bundle branch block (BBB), can cause reduced ventricular function. However, the effects of BBB on the mechanical function of heart are difficult to assess experimentally. Many heart models have been developed to investigate cardiac properties during BBB but have mainly focused on the electrophysiological properties. To date, the mechanical function of BBB has not been well investigated. Based on a three-dimensional electromechanical canine heart model, the mechanical properties of complete left and right bundle branch block (LBBB and RBBB) were simulated. The anatomical model as well as the fiber orientations of a dog heart was reconstructed from magnetic resonance imaging (MRI) and diffusion tensor MRI (DT-MRI). Using the solutions of reaction-diffusion equations and with a strategy of parallel computation, the asynchronous excitation propagation and intraventricular conduction in BBB was simulated. The mechanics of myocardial tissues were computed with time-, sarcomere length-dependent uniaxial active stress initiated at the time of depolarization. The quantification of mechanical intra- and interventricular asynchrony of BBB was then investigated using the finite-element method with an eight-node isoparametric element. The simulation results show that (1) there exists inter- and intraventricular systolic dyssynchrony during BBB; (2) RBBB may have more mechanical synchrony and better systolic function of the left ventricle (LV) than LBBB; (3) the ventricles always move toward the early-activated ventricle; and (4) the septum experiences higher stress than left and right ventricular free walls in BBB. The simulation results validate clinical and experimental recordings of heart deformation and provide regional quantitative estimates of ventricular wall strain and stress. The present work suggests that an electromechanical heart model, incorporating real geometry and fiber orientations, may be helpful for better

  8. Long-term outcomes of left bundle branch block in high-risk survivors of acute myocardial infarction: the VALIANT experience

    DEFF Research Database (Denmark)

    Stephenson, Kent; Skali, Hicham; McMurray, John J V;

    2006-01-01

    BACKGROUND: In survivors of myocardial infarction (MI), new left bundle branch block (LBBB) is associated with adverse outcomes, but its impact is not well described in post-MI patients with left ventricular (LV) systolic dysfunction and/or heart failure (HF). OBJECTIVES: The aim of this study wa...

  9. Right ventricular electrical and mechanical synchronization by properly timed septal pacing in a patient with right bundle branch block and first degree AV block--a case report.

    Science.gov (United States)

    Siliste, Calin; Suran, Maria-Claudia-Berenice; Margulescu, Andrei-Dumitru; Vinereanu, Dragos

    2015-03-01

    We present a case of near-normalization of the QRS by septal pacing in a patient with dual-chamber pacemaker and underlying complete right bundle branch block and first degree atrioventricular block. The right ventricular mechanical synchronization suggested by the ECG was validated as such by strain echo. To the best of our knowledge, this is the first time it has been shown that the narrowing of the QRS corresponds to mechanical synchronization in a case of this seldom-recognized phenomenon.

  10. Vectorcardiogram of complete right bundle branch block with left axis deviation by the Frank and Kimura systems.

    Directory of Open Access Journals (Sweden)

    Nakagawa,Masahiro

    1979-10-01

    Full Text Available Vectorcardiogram (VCG recorded by both the Frank and Kimura systems were examined in 45 patients with complete right bundle branch block (RBBB and left axis deviation (LAD to investigate the relationship seen on electrocardiogram (ECG between RBBB with LAD and bilateral bundle. The sample included: 13 cases of type SI, SII, SIII, SaVF; 21 cases of type SI, SII, SIII, aVF; and 11 cases of types SI, SII, SIII. VCG recorded by the Frank system were classified into seven types according to the QRS loop pattern on the frontal plane and into three types according to the horizontal plane. The main findings were: (a In the Frank system the QRS loop in the frontal plane showed a variety of patterns in RBBB with LAD. (b On VCG of complete RBBB judged complicated by a left anterior hemiblock by the Frank system, the main portion of the QRS loop extended to the left superior or merely to the left in the frontal plane. The direction of rotation and position on the horizontal plane were not consistent. (c The results of this study suggest the usefulness of the Kimura system as an auxiliary diagnostic technique.

  11. Defective T wave combined with incomplete right bundle branch block: a new electrocardiographic index for diagnosing atrial septal defect

    Institute of Scientific and Technical Information of China (English)

    WANG Mu-xuan; Andrew D.Michaels; MA Hong; WU Gui-fu; GU Jing-li; LI Li; LU Kun; YANG Da; CHEN Long; ZHANG Xi; LUO Fu-tian

    2012-01-01

    Background Incomplete right bundle branch block (ICRBBB) is commonly associated with atrial septal defect (ASD),but lacks sufficient diagnostic test characteristics.An abnormal T wave is also often observed in ASD,with horizontal or inverted displacement of the proximal T wave limb in the right precordial leads,termed "defective T wave" (DTW).Methods We examined the diagnostic test characteristics of combining ICRBBB with DTVV as a new index to diagnose ASD.A total of 132 consecutive patients with ASD and 132 cases of age/gender-matched controls without ASD were enrolled.Results Sensitivities of DTW,ICRBBB,and both were 87.1%-87.9%.Specificities were 97.0%,96.2%,and 100%,respectively.Positive predictive values were 1.3%,1.1%,and 100.0% respectively,while negative predictive values were 99.9% for each.Conclusion Combining ICRBBB with DTW in electrocardiogram (ECG) as a new index significantly increased the specificity and positive predictive values while maintaining a high sensitivity in diagnosing ASD.

  12. Electrocardiogram Performance in the Diagnosis of Left Ventricular Hypertrophy in Hypertensive Patients With Left Bundle Branch Block

    Science.gov (United States)

    Burgos, Paula Freitas Martins; Luna Filho, Bráulio; Costa, Francisco de Assis; Bombig, Maria Teresa Nogueira; de Souza, Dilma; Bianco, Henrique Tria; Oliveira Filho, Japy Angelini; Izar, Maria Cristina de Oliveira; Fonseca, Francisco Antonio Helfenstein; Póvoa, Rui

    2017-01-01

    Background Left ventricular hypertrophy (LVH) is an important risk factor for cardiovascular events, and its detection usually begins with an electrocardiogram (ECG). Objective To evaluate the impact of complete left bundle branch block (CLBBB) in hypertensive patients in the diagnostic performance of LVH by ECG. Methods A total of 2,240 hypertensive patients were studied. All of them were submitted to an ECG and an echocardiogram (ECHO). We evaluated the most frequently used electrocardiographic criteria for LVH diagnosis: Cornell voltage, Cornell voltage product, Sokolow-Lyon voltage, Sokolow-Lyon product, RaVL, RaVL+SV3, RV6/RV5 ratio, strain pattern, left atrial enlargement, and QT interval. LVH identification pattern was the left ventricular mass index (LVMI) obtained by ECHO in all participants. Results Mean age was 11.3 years ± 58.7 years, 684 (30.5%) were male and 1,556 (69.5%) were female. In patients without CLBBB, ECG sensitivity to the presence of LVH varied between 7.6 and 40.9%, and specificity varied between 70.2% and 99.2%. In participants with CLBBB, sensitivity to LVH varied between 11.9 and 95.2%, and specificity between 6.6 and 96.6%. Among the criteria with the best performance for LVH with CLBBB, Sokolow-Lyon, for a voltage of ≥ 3,0mV, stood out with a sensitivity of 22.2% (CI 95% 15.8 - 30.8) and specificity of 88.3% (CI 95% 77.8 - 94.2). Conclusion In hypertensive patients with CLBBB, the most often used criteria for the detection of LVH with ECG showed significant decrease in performance with regards to sensitivity and specificity. In this scenario, Sokolow-Lyon criteria with voltage ≥3,0mV presented the best performance. PMID:27992034

  13. Significance of QRS duration and left bundle branch block in development and course of congestive heart failure

    Directory of Open Access Journals (Sweden)

    Bockeria L. A.

    2012-03-01

    Full Text Available Patients with severe chronic heart failure (CHF often have such intraventricular conduction disturbances as left bundle branch block which show morphological and QRS-duration changes on ECG and result in evident intra- and interventricular dyssinchrony. Delayed left ventricular activation via interventricular septum results in evident asynchrony at the beginning of left and right ventricular contration. Diagnostic significance of ECG data increases in presence of CHF clinical signs, especially echocardiographic signs of myocardial dysfunction. EVEREST study analyzed the influence of QRS duration on number of hospital admissions and mortality in patients with CHF. The study included 2962 patients, 1614 of them had normal QRS duration – less than 120 ms, 1321 patients had increased QRS duration – more than 120 ms. 678 deaths occurred during followup period, 307 (18.7% of them were from group with normal QRS duration and 371 (28.1% – from group with increased QRS interval. Mortality rate due to cardiovascular causes was more significant in patients with increased QRS. In 3 months of follow-up the mortality rate was 21.1% in patients with increased QRS and 14.6% in patients with normal QRS. In 9.9 months of follow-up the rates were 41.6% and 32.4%, respectively. Different international studies showed that isolated right ventricular pacing resulted in prolongation of QRS complex and contributed to CHF progression. 2010 patients were randomized in MOST-study which aimed to compare dual chamber pacing and right ventricular pacing. Reduction of CHF symptoms was noted in the course of study in patients who underwent dual chamber pacing, while M.O. Sweeney et al. analyzed the results of treatment of 1339 patients with initially normal QRS duration. However the authors revealed a higher rate in group of right ventricular pacing which proved the higher rates of hospital admission for CHF and more frequent rates for atrial fibrillation occurrence

  14. Trastuzumab (Herceptin)-associated cardiomyopathy presented as new onset of complete left bundle-branch block mimicking acute coronary syndrome: a case report and literature review.

    Science.gov (United States)

    Tu, Chung-Ming; Chu, Kai-Ming; Yang, Shin-Ping; Cheng, Shu-Mung; Wang, Wen-Been

    2009-09-01

    Trastuzumab (Herceptin) is well documented in reducing suffering and mortality from breast cancer. The clinically most important side effect of Herceptin is cardiotoxicity, which is reported in 2.6% to 4.5% of patients receiving trastuzumab alone and in as many as 27% of patients when trastuzumab is combined with an anthracycline in metastatic disease. We reported the case of a 50-year-old woman who presented to our emergency department (ED) because of chest pain and shortness of breath. On physical examination, holosystolic murmur over apex could be heard. Pulmonary and abdominal examinations were unremarkable. Twelve-lead electrocardiography showed sinus tachycardia and new onset of complete left bundle-branch block. Emergent transthoracic echocardiography revealed generalized hypokinesia of left ventricle and akinesia over interventricular septum and apex. She subsequently underwent immediate coronary angiography that revealed normal coronary angiography, and left ventriculogram revealed generalized hypokinesia with severe left ventricle dysfunction with ejection fraction of 33%. During right heart catheterization and endomyocardial biopsy, cardiac tamponade developed and was successfully relieved by pericardial window. She was discharged event-free 3 weeks later with conservative treatment. Although new onset of complete left bundle-branch block in a patient with chest pain may be acute coronary syndrome, careful review of medicine history is mandatory to avoid unnecessary procedure and complications.

  15. Identification of Typical Left Bundle Branch Block Contraction by Strain Echocardiography Is Additive to Electrocardiography in Prediction of Long-Term Outcome After Cardiac Resynchronization Therapy

    DEFF Research Database (Denmark)

    Risum, Niels; Tayal, Bhupendar; Hansen, Thomas F;

    2015-01-01

    BACKGROUND: Current guidelines suggest that patients with left bundle branch block (LBBB) be treated with cardiac resynchronization therapy (CRT); however, one-third do not have a significant activation delay, which can result in nonresponse. By identifying characteristic opposing wall contraction......, 2-dimensional strain echocardiography (2DSE) may detect true LBBB activation. OBJECTIVES: This study sought to investigate whether the absence of a typical LBBB mechanical activation pattern by 2DSE was associated with unfavorable long-term outcome and if this is additive to electrocardiographic...... (ECG) morphology and duration. METHODS: From 2 centers, 208 CRT candidates (New York Heart Association classes II to IV, ejection fraction ≤35%, QRS duration ≥120 ms) with LBBB by ECG were prospectively included. Before CRT implantation, longitudinal strain in the apical 4-chamber view determined...

  16. Sequential SPECT/CT imaging starting with stress SPECT in patients with left bundle branch block suspected for coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Engbers, Elsemiek M.; Mouden, Mohamed [Isala, Department of Cardiology, Zwolle (Netherlands); Isala, Department of Nuclear Medicine, Zwolle (Netherlands); Timmer, Jorik R.; Ottervanger, Jan Paul [Isala, Department of Cardiology, Zwolle (Netherlands); Knollema, Siert; Jager, Pieter L. [Isala, Department of Nuclear Medicine, Zwolle (Netherlands)

    2017-01-15

    To investigate the impact of left bundle branch block (LBBB) on sequential single photon emission computed tomography (SPECT)/ CT imaging starting with stress-first SPECT. Consecutive symptomatic low- to intermediate-risk patients without a history of coronary artery disease (CAD) referred for SPECT/CT were included from an observational registry. If stress SPECT was abnormal, additional rest SPECT and, if feasible, coronary CT angiography (CCTA) were acquired. Of the 5,018 patients, 218 (4.3 %) demonstrated LBBB. Patients with LBBB were slightly older than patients without LBBB (65±12 vs. 61±11 years, p<0.001). Stress SPECT was more frequently abnormal in patients with LBBB (82 % vs. 46 %, p<0.001). After reviewing stress and rest images, SPECT was normal in 43 % of the patients with LBBB, compared to 77 % of the patients without LBBB (p<0.001). Sixty-four of the 124 patients with LBBB and abnormal stress-rest SPECT underwent CCTA (52 %), which could exclude obstructive CAD in 46 of the patients (72 %). Sequential SPECT/CT imaging starting with stress SPECT is not the optimal imaging protocol in patients with LBBB, as the majority of these patients have potentially false-positive stress SPECT. First-line testing using CCTA may be more appropriate in low- to intermediate-risk patients with LBBB. (orig.)

  17. Cardiac MRI assessment of right ventricular function: impact of right bundle branch block on the evaluation of cardiac performance parameters

    Energy Technology Data Exchange (ETDEWEB)

    Marterer, Robert; Tschauner, Sebastian; Sorantin, Erich [Medical University of Graz, Division of Pediatric Radiology, Department of Radiology, Graz (Austria); Zeng, Hongchun [First Affiliated Hospital of Xinjiang Medical University, Department of Ultrasonography, Urumqi (China); Koestenberger, Martin [Medical University of Graz, Division of Pediatric Cardiology, Department of Pediatrics and Adolescent Medicine, Graz (Austria)

    2015-12-15

    Right ventricular (RV) function represents a prognostic marker in patients with corrected congenital heart disease. In up to 80 % of these patients, right branch bundle block (RBBB) exists and leads to asynchronous ventricular contraction. The aim of this retrospective study was to evaluate the change of RV performance parameters considering delayed RV end-systolic contraction. RV volumes of 33 patients were assessed twice: 1) not taking account of RBBB (group I), and 2) considering RBBB (group II). According to the RV ejection fraction (EF) for both groups, RV function was classified in different categories (>50 % = normal, 40-50 % = mildly-, 30-40 % = moderately-, <30 % = severely-reduced). The mean time difference between maximal systolic contraction of the septum and RV free wall was 90.7 ms ± 42.6. Consequently, RV end-systolic volume was significantly decreased in group II (p < 0.001). Accordingly, RV stroke volume and RV EF were significantly higher in group II (p < 0.001). There was also a significant change in the assessment of RV function (p < 0.02). RBBB induced delayed RV contraction can be detected at CMR. Ignoring the RV physiology in RBBB patients leads to a statistically significant underscoring of RV performance parameters. (orig.)

  18. In Heart Failure Patients with Left Bundle Branch Block Single Lead MultiSpot Left Ventricular Pacing Does Not Improve Acute Hemodynamic Response To Conventional Biventricular Pacing. A Multicenter Prospective, Interventional, Non-Randomized Study

    OpenAIRE

    Maciej Sterliński; Adam Sokal; Radosław Lenarczyk; Frederic Van Heuverswyn; Aldo Rinaldi, C.; Marc Vanderheyden; Vladimir Khalameizer; Darrel Francis; Joeri Heynens; Berthold Stegemann; Richard Cornelussen

    2016-01-01

    Introduction Recent efforts to increase CRT response by multiSPOT pacing (MSP) from multiple bipols on the same left ventricular lead are still inconclusive. Aim The Left Ventricular (LV) MultiSPOTpacing for CRT (iSPOT) study compared the acute hemodynamic response of MSP pacing by using 3 electrodes on a quadripolar lead compared with conventional biventricular pacing (BiV). Methods Patients with left bundle branch block (LBBB) underwent an acute hemodynamic study to determine the %change in...

  19. Dilated cardiomyopathy and left bundle branch block associated with ingestion of colloidal gold and silver is reversed by British antiLewisite and vitamin E: the potential toxicity of metals used as health supplements.

    Science.gov (United States)

    Archer, Stephen Lawrence

    2008-05-01

    A case of left bundle branch block and a dilated, nonhypertrophic cardiomyopathy associated with ingestion of colloidal gold and silver as an 'energy tonic' is described. The cardiac disease was reversed within two months by a course of dimercaprol (Akorn Inc, USA) (British antiLewisite) and vitamin E. This is the first case of gold and silver cardiomyopathy in humans, and highlights the risks of these colloidal metal 'health supplements'.

  20. Diastolic function of the left ventricle in patients with cardiomyopathy and low ejection fraction: the role of torsion in left bundle branch block

    Directory of Open Access Journals (Sweden)

    E. N. Pavlyukova

    2016-01-01

    Full Text Available Influence of left bundle branch block (LBBB on left ventricle (LV diastolic function and mechanisms of LV torsion remains underestimated.Aim. To study the relationship of LV diastolic function and LV torsion in patients with cardiomyopathy and LBBB in comparison with patients with cardiomyopathy and normal intraventricular conduction.Material and methods. Patients with cardiomyopathy (n=74 and LV ejection fraction <40% were included into the study and divided in two groups with narrow QRS complex and LBBB (the mean QRS duration = 153 ms. Echocardiography was performed in all patients with hemodynamic indices detection, and myocardium strain and torsion estimation.Results. The patients with LBBB showed less twisting, than patients without LBBB (3.24±3.35° and 5.87±3.83°, respectively, p=0.013914, but significant diastolic function differences between groups were absent. Despite the lack of difference in heart remodeling indices, subgroup of patients with LV rigid body rotation showed significantly less LV twisting and changes in pulmonary vein flow related to LV high end diastolic pressure. In the rigid body rotation group systolic left atrial filling fraction was 32.3±8.07%, whereas in the group with a physiological counter-rotation - 53.1±10.1% (p=0.000226. Potential reason of these findings was interventricular dyssynchrony. Deviation of time interval to peak myocardial systolic velocity between opposite basal segments in group with LBBB and anomalous LV rotation was more (63.3±35.1 ms than this in group with LBBB and physiological LV rotation (8.0±17.9 mc, p=0.015922. This finding suggests that LV rigid body rotation in patients with LBBB may reflect a more pronounced mechanical dyssynchrony.Conclusion. LBBB has complex negative influence on process of LV electric activation and contraction which results in deterioration of LV twisting, mechanical dyssynchrony and deterioration of diastolic function. In disorders of intraventricular

  1. Clinical observation of ECG in diagnosis of acute myocardial infarction with bundle branch block%心电图诊断急性心肌梗死合并束支阻滞的临床观察

    Institute of Scientific and Technical Information of China (English)

    吴梅花

    2016-01-01

    Objective Discussion of electrocardiographic diagnosis of acute myocardial infarction clinical significance of bundle branch block..Methods From March 2014 to December 2015,72 patients with acute myocardial infarction in patients with bundle branch block as the object of study,after ECG for patients,respectively,traditional programmes and Sgarbossa diagnosis scheme for diagnostic purposes. Observation and comparison of two diagnosis results of the programme.Results The two methods in the negative predictive and diagnostic sensitivity of no significant difference but Sgarbossa positive predictive diagnosis method of rate and specificity than conventional methods.Conclusion Sgarbossa judge diagnosis,can effectively improve the accuracy of electrocardiogram in diagnosis of myocardial infarction.%目的:讨论心电图诊断急性心肌梗死合并束支阻滞的临床意义。方法选取2014年3月至2015年12月,72例患有急性心肌梗死合并束支阻滞的患者为研究对象,对患者进行心电图检查之后,分别以传统诊断方案和Sgarbossa诊断方案进行诊断。观察和比较两中诊断方案的结果。结果两种方法在阴性预测率和诊断敏感性的比较上没有显著差异,但是用Sgarbossa诊断方法的阳性预测率和特异性明显高于传统方法。结论应用Sgarbossa诊断方案进行判断,可以有效的提高心电图诊断心肌梗死的准确率。

  2. Analysis of 1 case with intermittent left bundle branch block caused by high doses of beta blocker%大剂量β受体阻滞剂致间歇性左束支传导阻滞1例分析

    Institute of Scientific and Technical Information of China (English)

    王清丽; 金向梅; 张力; 赵激扬

    2014-01-01

    We have treated 1 case with intermittent left bundle branch block caused by high doses of beta blocker.We briefly reported the treatment experience.%在临床治疗了1例大剂量β受体阻滞剂致间歇性左束支传导阻滞的患者,现将体会简要报告。

  3. Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block; Perfusao miocardica de estresse com dipiridamol por tomografia computadorizada em pacientes com bloqueio de ramo esquerdo

    Energy Technology Data Exchange (ETDEWEB)

    Cabeda, Estevan Vieira; Rochitte, Carlos Eduardo; Nomura, Cesar Higa; Parga, Jose Rodrigues; Avila, Luiz Francisco Rodrigues; Falcao, Andrea Maria Gomes; Soares Junior, Jose [Instituto do Coracao (InCor), Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil)

    2015-12-15

    Background: Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB). Objective: To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP) by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA) (stenosis ≥ 70%) as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA) and compare the results with those of single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy. Methods: Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography. Independent examiners performed per-patient and per-coronary territory assessments. All patients gave written informed consent to participate in the study that was approved by the institution's ethics committee. Results: The patients' mean age was 62 ± 10 years. The mean dose of radiation for the tomography protocol was 9.3 ± 4.6 mSv. With regard to CTP, the per-patient values for sensitivity, specificity, positive and negative predictive values, and accuracy were 86%, 81%, 80%, 87%, and 83%, respectively (p = 0.001). The per-territory values were 63%, 86%, 65%, 84%, and 79%, respectively (p < 0.001). In both analyses, the addition of CTP to CTA achieved higher diagnostic accuracy for detecting myocardial ischemia than SPECT (p < 0.001). Conclusion: The use of the stress tomography protocol is feasible and has good diagnostic accuracy for assessing myocardial ischemia in patients with LBBB. (author)

  4. Lesson Eighteen An Unusual Bundle Branch Block

    Institute of Scientific and Technical Information of China (English)

    鲁端; 王劲

    2006-01-01

    @@ The electrocardiographic(Fig. 1) has been recorded from an asymptomatic 52-year-old woman free from organic heart disease,who was admitted to the outpatient department beacause a routine ECG had pointed out some abnormalities1: ①The QRS axis is at +90°, ②The QRS duration is 0.14 seconds, ③ The QRS configuration in the limb leads is suggestive of BBB, but it is hard to define, on the basis of these leads only, which type of BBB (right or left) is involved2.The wide S waves in leads I and aVL suggest at first glance an RBBB, whereas the QRS morphology in the inferior leads (monophasic R wave with secondary ST-T changes) is more consistent with an LBBB with relative right axis deviation, ④The chest leads further complicate the problem because lead V1 suggests an RBBB, whereas leads V5 and V6 are perfectly consistent with an LBBB, showing a monophasic R wave3, in addition, lead V5 shows ST-segment depression and negative T wave, typical of LBBB. It is worth noting that when the tracing was recorded, the correct placement of precordial electrodes was accurately checked, ⑤ Placement of precordial electrodes of leads V4,V5,and V6 2 intercostals spaces above restores4,in these leads, a QRS configuration suggestive of RBBB:small and relatively wide s waves appear and the T waves become positive.

  5. 左束支阻滞激动模式:心功能不良重要的可逆性因素%The exaitation mode of left bundle branch block:an important reversible factor of heart failure

    Institute of Scientific and Technical Information of China (English)

    单其俊; 邹建刚; 陈椿; 杨兵; 陈明龙; 徐东杰; 侯小峰; 曹克将

    2009-01-01

    目的 观察左束支阻滞激动模式对心脏功能和结构的影响.方法 3例心功能不良和左心室扩大患者,左心室射血分数(LVEF)0.44 ±0.11,左心室舒张末内径(LVEDD)(56±4)mm,QRS时限增宽(177±15)ms,呈左束支阻滞或左束支阻滞样图形.例1为风湿性心脏病二尖瓣及主动脉瓣置换术后伴左束支阻滞;例2为显性右侧预激综合征;例3 24 h动态心电图示右心室流出道室性早搏(室早)3万次.结果 例1成功行心脏再同步治疗,例2和例3成功行右侧显性旁路和右心室流出道室早消融,QRS时限降至(103±25)ms,随访6~30个月,症状明显改善,心功能恢复正常,左心室明显缩小,LVEF为0.65 ±0.04和LVEDD(48±4)mm.结论 左束支阻滞激动模式是心功能不良重要的可逆性因素.%Objective To investigate the effects of excitation mode of left bundle branch block (LBBB) or LBBB-like on the cardiac function and structure.Methods This study included three patients with depressing cardiac function (LVEF=0.44±0.11 ) and enlarged left ventricle [LVEDD=(56+4)mm).The widen QRS complex (QRS duration=(177±15 )ms] displayed LBBB or LBBB-like was documented in all patients.One patient with serious heart failure had the history of surgical mitral and aortic valves replacement and LBBB.The right ventricular preexcitation and frequent premature ventricular contractions ( more than 30 000 beats per 24 hours) were documented in other 2 patients,respectively.Results The patient with surgical valves replacement and LBBB underwent successful cardiac resynchrunization therapy with biventricular pacing.The para-Hisian accessory pathway and premature ventricular contractions originated from right ventricular outflow tract were ablated successfully in other patients,respectively.After the procedures,the QRS complex became significant narrow [QRS duration=(103±25)ms) in all patients.During the follow-up period of 6 to 30 months,the cardiac function ( LVEF=0.65±0

  6. Short-Term Effect of Right Atrial and Left Uni-Ventricular Pacing in Patients of Chronic Heart Failure With Left Bundle-Branch Block%右心房、左心室起搏治疗慢性心力衰竭伴左束支传导阻滞患者的短期疗效

    Institute of Scientific and Technical Information of China (English)

    邱春光; 王徐乐; 韩战营; 卢文杰; 陈晓杰

    2012-01-01

    目的:观察右心房、左心室起搏治疗慢性心力衰竭(心衰)伴左束支传导阻滞患者的短期疗效.方法:选择纽约心功能分级(NYHA)Ⅲ级~Ⅳ级、左心室射血分数≤0.35、体表心电图QRS时限≥120 ms、窦性心律的心衰患者26例,成功植入三腔起搏器后,以右心房、左心室起搏模式治疗7天,以起搏器植入术前及术后第7天的6分钟步行距离、明尼苏达生活质量评分、QRS波时限、左心室舒张末期内径、左心室射血分数、左心室室间隔部与侧壁基底段收缩期达峰时间差值、N末端脑钠肽为疗效评价指标,观察右心房、左心室起搏治疗慢性心衰的短期疗效.结果:右心房、左心室起搏治疗术后第7天较术前比较,6分钟步行距离由术前的( 279±46)m提高至(312±37)m;明尼苏达生活质量评分由术前的(28±7)下降至(22±5);体表心电图QRS波时限由术前的(167±22)ms缩短至(132±8)ms;左心室射血分数由术前的(0.29±0.07)提高至(0.33±0.05);左心室舒张末期内径由术前的(75±8)mm减小至(69±7)mm;左心室室间隔部与侧壁基底段收缩期达峰时间差值由术前的(105±29)ms下降至(62±8)ms;N末端脑钠肽由术前的(3 086±1 265)pg/ml下降至(1 976±760)pg/ml;患者的各疗效评价指标均得到明显改善,差异均有统计学意义(P<0.05).结论:对窦性心律、完全性左束支传导阻滞的慢性心衰患者右心房、左心室起搏的短期疗效确切.%Objective:To observe the short-term effect of right atrial and left uni-ventricular pacing in patients of chronic heart failure with left bundle-branch block.Methods; A total of 26 heart failure patients who had NYHA class III to IV .with sinus rhythm,left ventricular ejection fraction (LVEF) ≤ 0. 35, QRS duration ≥s 0. 12 ms were studied after successful implantation of CRT/CRTD. All patients received right atrial and left uni-ventricular pacing for 7 days. The therapeutic effects

  7. 记分法判别完全性右束支传导阻滞性质的价值研究%The study of the value of scoring method used in distinguishing the nature of complete right bundle branch block

    Institute of Scientific and Technical Information of China (English)

    戴伟川; 冉启川

    2013-01-01

    Objective To study the value of scoring method used in distinguishing the nature of complete right bundle branch block (CRBBB).Methods The CRBBB relevant parameters of 128 cases organic heart disease patients and those of 144 cases of healthy people were compared.Results The compositions of scoring method are:CRBBB with primary ST-T change、Cardiac electric axis left deviation<-30°or right deviation>+110°、J-Tc interval>0.32s (five points for each),QRS wave time ≥0.16s (four points)、QRS wave time>0.14s、V1 lead R peak time≥0.10s (three points),V5 lead S wave duration>0.08s、age≥60 year (two points for each),total score ≥5 points,it will be judged as pathological CRBBB,if it is <5,it will be judged as functional CRBBB.Using the single index to distinguish CRBBB led to low sensitiveness(2.34%~83.59%) and specificity (22.22%~100.00%),while using the scoring method generated high sensitiveness (85.16%) and specificity(91.67%),as well as higher accuracy(88.60%).Conclusions The scoring method is a good way of distinguishing the nature of CRBBB in clinical application.%目的 探讨记分法判别完全性右束支传导阻滞(CRBBB)性质的价值.方法 比较128例器质性心脏病患者和144例健康人CRBBB相关参数,并按阳性预测值高低赋予不同分值,构成记分法标准.结果 记分法构成,CRBBB伴原发性ST-T改变、心电轴左偏<-30°或右偏>+110°、J-Tc间期>0.32s各记5分,QRS波时限≥0.16s记4分,V1导联R峰时间≥0.10s记3分,QRS波时限>0.14s、v5导联S波时限>0.08s、年龄≥60岁各记2分,总积分≥5分者判为病理性CRBBB,<5分者判为功能性CRBBB.单项指标判别CRBBB性质敏感度低(2.34%~83.59%)或特异度不高(22.22%~1 00.00%),记分法判别CRBBB性质则有较高敏感度(85.16%)、特异度(91.67%)和预测准确性(88.60%).结论 记分法对判别CRBBB性质有较好的临床应用价值.

  8. Left ventricular regional contraction abnormalities by echocardiographic speckle tracking in combined right bundle branch with left anterior fascicular block compared to left bundle branch block

    DEFF Research Database (Denmark)

    Leeters, Irene P M; Davis, Ashlee; Zusterzeel, Robbert;

    2016-01-01

    BACKGROUND: In contrast to LBBB patients less is known about patients with RBBB+LAFB regarding LV contractile abnormalities and the potential role of CRT. This study investigated whether patients with RBBB+LAFB morphology have echocardiographic mechanical strain abnormalities between the inferior...... and anterior LV walls, similar to abnormalities between septal and lateral walls in LBBB. METHODS AND RESULTS: Ten healthy volunteers with no-BBB, 28 LBBB and 28 RBBB+LAFB heart failure patients were included in this retrospective study. Two-dimensional regional-strains were obtained by speckle-tracking. Scar...... was assessed by CMR. Response on echo was defined as normal, classical, borderline or other pattern. The number of classical patterns in LBBB was significantly higher than in RBBB+LAFB and no-BBB groups (p

  9. Incomplete right bundle branch block: a novel electrocardiographic marker for lone atrial fibrillation

    DEFF Research Database (Denmark)

    Nielsen, Jonas Bille; Olesen, Morten Salling; Tangø, Mogens;

    2011-01-01

    electrocardiographic (ECG) markers from patients with early-onset lone AF and from a healthy control population. We included 187 patients with early-onset lone AF and 383 healthy controls. Sixty-two lone AF patients were excluded from the study because of AF at the time of enrolment or because of the use...

  10. New strict left bundle branch block criteria reflect left ventricular activation differences

    DEFF Research Database (Denmark)

    Emerek, Kasper Janus Grønn; Risum, Niels; Hjortshøj, Søren Pihlkjær;

    2015-01-01

    applying new strict ECG criteria subsequent rates of response in DCM were 18/19 (95%) and in IHD of 18/23 (78%) respectively, p... ventricular electrical delay (RV-LV-IED) was measured. Response to CRT was defined as ≥15% decrease in left ventricular end-systolic volume. RESULTS: Eighteen of 20 (90%) patients with non-ischemic dilated cardiomyopathy (DCM) and 18 of 29 (62%) with ischemic heart disease (IHD) responded to CRT, p.... CONCLUSION: Interventricular electrical delay predicts left ventricular remodeling after CRT and new, strict ECG criteria of LBBB are superior in predicting remodeling....

  11. A Clinical and Follow-up Study of Right and Left Bundle Branch Block

    Science.gov (United States)

    1974-09-03

    acute myocardial infarction and one with chronic !ung disease and cor pulmonale ). Of the nine BBBB subjects with an initial diagnosis of hyperten...complicated In cor pulmonale . and for one, the cause of death was not available. Of the nine LBBB patients who died, five died of conditions related...the RBBB group, i and 2’r had cor - onarx heart disease and hypertension, respectively; in LBBB subjects, 9 and ~’i had coronarv heart disease and h

  12. Tachycardia-dependent bilateral bundle branch block in ischemic heart disease with systolic dysfunction: case report and review of prognostic implications

    Directory of Open Access Journals (Sweden)

    Federico Ferrando-Castagnetto

    2015-10-01

    Full Text Available Una caracterización correcta de los bloqueos de rama dependientes de frecuencia, puede proporcionar información relevante en ciertas situaciones clínicas. A menudo, este evento fisiológico puede evidenciar la presencia de un daño extenso del sistema de conducción infrahisiano con riesgo elevado de bloqueo aurículo-ventricular avanzado y necesidad de implante de marcapasos. Describimos el caso de un hombre de 62 años con cardiopatía isquémica crónica, que exhibió un bloqueo de rama bilateral alternante taquicardia-dependiente durante el esfuerzo ergométrico, discutiendo las principales implicancias pronósticas de este evento inusual en el contexto de la disfunción sistólica.

  13. Comparative Long-Term Outcomes after Cardiac Resynchronization Therapy in Right Ventricular Paced Patients versus Native Wide Left Bundle Branch Block Patients

    DEFF Research Database (Denmark)

    Tayal, Bhupendar; Gorcsan, John; Delgado-Montero, Antonia

    2016-01-01

    a single center (85 (63%) with native wide LBBB and 50 (37%) with RVP) were studied prospectively. Baseline left ventricular typical contraction pattern was determined using speckle tracking echocardiography in the apical 4-chamber view. The predefined end point was death, heart transplantation, or left...

  14. Lesson Thirteen Trifascicular Block

    Institute of Scientific and Technical Information of China (English)

    鲁端; 王劲

    2005-01-01

    @@ A complete trifascicular block would result in complete AV block. The idio ventricular rhythm has a slower rate and a wide QRS complex because the pacemaker is located at the peripheral part of the conduction system distal to the sites of the block1. Such a rhythm may be difficult to differentiate from bifascicular or bundle branch block combined with complete block at a higher level such as the AV node or His bundle2. Besides a slower ventricular rate, a change in the morphology of the QRS complex from a previous known bifascicular pattern would be strongly suggestive of a trifascicular origin of the complete AV block3. A His bundle recording is required for a definitive diagnosis, however.

  15. Acute Pulmonary Thromboembolism Presenting As Complete Heart Block - A Rare Presentation

    Directory of Open Access Journals (Sweden)

    Vikash Goyal

    2015-08-01

    Full Text Available Acute pulmonary thromboembolism (PTE is a life threatening condition which requires early diagnosis and management. Electrocardiogram (ECG is helpful for suspecting the disease. The various ECG changes are sinus tachycardia, P pulmonale, Right bundle branch block (RBBB -incomplete or complete, axis shift, S1Q3T3, T wave inversion, and ST-segment depression in leads V1-4, aVF, and Lead III, supra ventricular tachycardia, low voltage QRS complex in limb leads. In addition, sinus bradycardia and complete heart block (CHB can be seen. CHB has been reported as an exceptionally rare manifestation of acute PTE. Here, we are reporting a case of 66 year old male presented with CHB with acute pulmonary thromboembolism, who reverted to sinus rhythm after thrombolysis.

  16. Dispersión del QRS como índice de disincronía en el bloqueo de rama izquierda y de sincronía tras la terapia de resincronización cardíaca, una variable de respuesta exitosa / QRS dispersion as an index of dyssynchrony in left bundle branch block and of

    Directory of Open Access Journals (Sweden)

    Elibet Chávez González

    2015-08-01

    Full Text Available Introducción: En pacientes con insuficiencia cardíaca, el bloqueo de rama izquierda del haz de His constituye un importante marcador de mal pronóstico, en ellos la tera-pia de resincronización puede mejorar la función del ventrículo izquierdo. Objetivo: Describir variables electrocardiográficas asociadas a una mejor respuesta de la resincronización cardíaca. Método: Se estudiaron 19 pacientes, 7 mujeres y 12 hombres con bloqueo de rama izquierda y fracción de eyección ≤ 35 %. Se realizó electrocardiograma antes y des-pués de la terapia de resincronización, medición del QRS en las doce derivaciones y cálculo de su dispersión, se midieron voltajes máximos del QRS, y se realizaron eco-cardiografías antes y después del procedimiento. Resultados: La fracción de eyección se incrementó desde 29,8±4,7 hasta 41,2±10,7 % (p=0.000. La correlación lineal entre fracción de eyección y dispersión del QRS a los seis meses de seguimiento fue significativa (r=0.34 y p=0.02; las mujeres presentaron mayor dispersión del QRS (48,0±24,0 vs. 37,14±13,8 ms; p=0.04. Los voltajes del QRS fueron predominantemente negativos en aVR (-0,52±0,58 vs. 0,28±0,42 mvolt; p=0.032 y positivos en V5 (0,71±1,12 vs. -0,15±1,20 mvolt; p=0.023 para los responde-dores en relación con los no respondedores. Conclusiones: La dispersión del QRS incrementada en el electrocardiograma con blo-queo de rama izquierda y la disminución de la dispersión del QRS posresincronización demostraron correlaciones significativas con la fracción de eyección; además, el es-trechamiento del QRS tras la resincronización fue significativo para los respondedo-res. Los voltajes predominantemente positivos en aVR y negativos en V5, pudieran predecir cuáles pacientes no responderán adecuadamente a la terapia de resincroni-zación cardíaca.

  17. Ablação de taquicardia ventricular idiopática com morfologia de bloqueio de ramo esquerdo localizada no tronco da artéria pulmonar Ablation of idiopathic ventricular tachycardia with left bundle-branch block morphology located in the pulmonary trunk

    Directory of Open Access Journals (Sweden)

    Luiz Roberto Leite

    2005-02-01

    Full Text Available Paciente de 26 anos, sem cardiopatia estrutural, apresentando palpitações e pré-síncopes devido à taquicardia ventricular não sustentada, foi submetida a estudo eletrofisiológico para tentativa de ablação do foco arritmogênico, usando-se como local, os critérios de mapeamento. Sem obter êxito com o mapeamento da via de saída do ventrículo direito, posicionou-se o cateter dentro da artéria pulmonar com mapeamento de foco satisfatório, eliminando a taquicardia tão logo iniciada a radiofreqüência. Durante seguimento de 14 meses, a paciente permanece assintomática, sem arritmia ao Holter e não nessecitando de drogas antiarrítmicas.We report the case of a 26-year-old female patient with palpitations and presyncopes due to nonsustained ventricular tachycardia, who had no structural heart disease. The patient underwent electrophysiological study in an attempt to ablate the arrhythmogenic focus, whose location was determined by using mapping criteria. Because mapping of the right ventricular outflow tract was not successful, the catheter was placed inside the pulmonary artery with satisfactory mapping of the arrhythmogenic focus, and tachycardia was eliminated as soon as radiofrequency was initiated. The patient has remained asymptomatic for 14 months, with no treatment with antiarrhythmic drugs, and no arrhythmias on serial 24-hour Holter.

  18. Radiotherapy as a cause of complete atrioventricular block in Hodgkin's disease: an electrophysiological-pathological correlation

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, S.I.; Bharati, S.; Glass, J.; Lev, M.

    1981-04-01

    A 20-year-old man contracted Hodgkin's disease and was treated with mantle radiotherapy. Heart block developed 11 years later. Electrocardiograms revealed predominant atrioventricular (AV) block and occasional AV conduction. Intracardiac electrograms demonstrated that the site of AV block was above the level of the His bundle. A permanent transvenous pacemaker was implanted. Seven months later the patient died of complications from cryptococcal meningitis. Pathological study of the heart revealed marked arteriosclerosis with fibrosis of the epicardium, myocardium, and endocardium. Examination of the conduction system revealed extensive arteriolosclerosis of the sinoatrial node and its approaches. In addition, there was marked fibrosis of the approaches to the AV node, the AV bundle, and both bundle branches. There was no evidence of Hodgkin's disease. This case documents the rare occurrence of AV block due to tissue destruction by radiotherapy. There was a good correlation between block proximal to the His bundle recording site and fibrosis of the approaches to the AV node.

  19. Radiotherapy as a cause of complete atrioventricular block in Hodgkin's disease. An electrophysiological-pathological correlation

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, S.I.; Bharati, S.; Glass, J.; Lev, M.

    1981-04-01

    A 20-year-old man contracted Hodgkin's disease and was treated with mantle radiotherapy. Heart block developed 11 years later. Electrocardiograms revealed predominant atrioventricular (AV) block and occasional AV conduction. Intracardiac electrograms demonstrated that the site of AV block was above the level of the His bundle. A permanent transvenous pacemaker was implanted. Seven months later the patient died of complications from cryptococcal meningitis. Pathological study of the heart revealed marked arteriosclerosis with fibrosis of the epicardium, myocardium, and endocardium. Examination of the conduction system revealed extensive arteriolosclerosis of the sinoatrial node and its approaches. In addition, there was marked fibrosis of the approaches to the AV node, the AV bundle, and both bundle branches. There was no evidence of Hodgkin's disease. This case documents the rare occurrence of AV block due to tissue destruction by radiotherapy. There was a good correlation between block proximal to the His bundle recording site and fibrosis of the approaches to the AV node.

  20. Rock blocks

    OpenAIRE

    Turner, W.

    2007-01-01

    Consider representation theory associated to symmetric groups, or to Hecke algebras in type A, or to q-Schur algebras, or to finite general linear groups in non-describing characteristic. Rock blocks are certain combinatorially defined blocks appearing in such a representation theory, first observed by R. Rouquier. Rock blocks are much more symmetric than general blocks, and every block is derived equivalent to a Rock block. Motivated by a theorem of J. Chuang and R. Kessar in the case of sym...

  1. Population Blocks.

    Science.gov (United States)

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  2. Esclerosis sistémica complicada con síncope y bloqueo AV completo Systemic sclerosis complicated with syncope and complete AV block

    Directory of Open Access Journals (Sweden)

    Francisco Femenía

    2010-10-01

    Full Text Available La esclerosis sistémica es una compleja enfermedad que afecta el tejido conectivo, el sistema vascular y el sistema inmunológico, y se caracteriza por fibrosis cutánea y de órganos viscerales. Los bloqueos de rama y los hemibloqueos se presentan en el 25 a 75% de los casos y constituyen predictores independientes de mortalidad. Los bloqueos auriculoventriculares de segundo o tercer grado son muy raros. Presentamos el caso de una mujer de 47 años de edad, con diagnóstico de esclerosis sistémica, quien presenta episodio sincopal secundario a bloqueo auriculoventricular completo con necesidad de implante de marcapasos definitivo.Systemic sclerosis is a complex disease that affects the connective tissue, the vascular system and the immune system. It typically produces skin and organ fibrosis. Cardiac bundle branch blocks and fascicular blocks occur in 25-75% of the cases and were found to be independent predictors of mortality. Second and third degree atrioventricular block are very rare. We present the case of a 47 year-old female with diagnosis of systemic sclerosis, presented with syncope secondary to complete atrioventricular block requiring permanent pacemaker implantation.

  3. Zitongdong Block

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    @@ The Zitongdong Block (Eastern Zitong Block) is located in the northwest of the Sichuan Basin. Tectonically, it is situated in the east part of Zitong Depression, southeast of mid-Longmenshan folded and faulted belt( as shown on Fig. 8 ), covering an area of 1 730 km2. The traffic is very convenient, the No. 108 national highway passes through the north of the block. Topographically, the area belongs to low hilly land at the elevation of 500-700 m.

  4. Pathology of complete atrioventricular block in chronic chagas' myocarditis

    Directory of Open Access Journals (Sweden)

    Zilton A. Andrade

    1988-03-01

    Full Text Available Sclero-atrophy, fibrosis, vascular ectasia, phlebosclerosis and mild non-specific chronic inflammatory changes were observed in variable location and proportion involving the atrioventricular conducting tissue of the heart in five human cases of chronic Chagas' myocarditis associated with complete atrioventricular block. One case presented complete destruction of the A-V conduction system. In three cases the lesions were disseminated all along the conducting tissue but did not cause anywhere a complete disruption in the continuity of the system. The distal portion of the bundle branches were the most damaged sector of the system, exceptfor the fasciculi of the posterior division of the left bundle branch which were relatively preserved. One case exhibited bilateral sclero-atrophy of the bundle branches as the main change; and another showed early and mild fibrocalcific damage of the penetrating portion of the His bundle. The A-V node appeared as the least involved part of the conducting system in the cases studied. Demonstration of the lesions in this series of cases seems important because: a it reveals that complete atrioventriculr block in chronic Chagas' disease results from disseminated lesions and not from focal disruptive change as has been commonly observed in cases of other etiologies; b it shows that chronic inflammation can produce at the end variable and widespread vascular, degenerative andfibrotic alterations within the conducting tissue of the heart, which may lead to its total destruction.O estudo do sistema de condução atrioventricular através cortes seriados completos em cinco casos humanos de miocardite crônica chagásica e bloqueio A-V total revelou a presença de lesões de esclero-atrofia, fibrose, ectasia vascular, fleboesclerose e inflamação crônica inespeclfica envolvendo o sistema de maneira disseminada, mas com distribuição e intensidade variáveis de caso para caso. Em um caso, todo o sistema, do nódulo A

  5. Zitongxi Block

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    @@ Zitongxi Block (Western Zitong Block), is located in Zitong County, northwest of Sichuan Province (as shown on Fig. 8 ). Geologically. it is situated in the Zitong Depression, southwest of the middle Longmenshan faulted and folded belt, covering an area of 1 830 km2. Transportation is very convenient. A crisscross network of highways run through the block and the Baocheng railway is nearby. The climate is moderate. Most area belongs to hilly land with the elevation of 500-600 m.The Tongjiang River runs across the area.

  6. Chengzikou Block

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    @@ Chengzikou Block is located in the north of Hekou district, Dongying City, Shandong Province, adjacent to Bohai Bay. It can be geographically divided into three units: onshore, transitional zone and offshore ultrashallow zone, totally covering an area of 470 km2. The southern onshore area is low and gentle in topography;the northern shallow sea is at water depths of 2-8 m below sea level, and the transitional zone occupies more than 60% of the whole block. The climate belongs to temperate zone with seasonal wind. Highways are welldeveloped here, and the traffic is very convenient. The Chengzikou Block is about 80 km away from Dongying City and 290 km from Jinan City in the south. The northern offshore area of the block is 160 km away from Longkou port in the east and only 38 km away in the west from Zhuangxi port.

  7. Longmenshan Block

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    @@ Longmenshan Block is located in Jiange County of Jiangyou City in the northwest of Sichuan Basin. covering an area of 2 628 km2. Geologically, it is situated in the Mid-Longmenshan fault and fold belt, neighbouring Zitong Depression in its southeast. There are mountains surrounding its northwest , the rest area being hilly land,with the elevation of 500-700 m. The BaoCheng railway and the No. 108 highway run through the block, the traffic is very convenient.

  8. Chadong Block

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    @@ The Chadong Block, located in the east of Qaidam Basin, Qinghai Province, covers an area of 12 452 km2. It is bounded by Kunlum Mountains in the south and the northwest is closely adjacent to Aimunike Mountain.Rivers are widely distributed, which always run in NWSE direction, including the Sulunguole, Qaidam and Haluwusu Rivers. The traffic condition is good, the Qinghai-Tibet highway stretching through the whole area and the Lan-Qing railway, 20-50 km away from the block, passing from north to west. A lot of Mongolia minority people have settled there, of which herdsmen always live nearby the Qaidam River drainage area.

  9. Ultrasound guided supraclavicular block.

    LENUS (Irish Health Repository)

    Hanumanthaiah, Deepak

    2013-09-01

    Ultrasound guided regional anaesthesia is becoming increasingly popular. The supraclavicular block has been transformed by ultrasound guidance into a potentially safe superficial block. We reviewed the techniques of performing supraclavicular block with special focus on ultrasound guidance.

  10. Block Cipher Analysis

    DEFF Research Database (Denmark)

    Miolane, Charlotte Vikkelsø

    Block ciphersarecryptographicprimitivesthatoperateon fixed sizetexts(blocks). Mostdesigns aim towards secure andfastencryption oflarge amounts ofdata. Block ciphers also serve as the building block of a number of hash functions and message authentication codes(MAC).Thetask of cryptanalysisisto en...... on small scale variants of AES. In the final part of the thesis we present a new block cipher proposal Present and examine its security against algebraic and differential cryptanalysis in particular.......Block ciphersarecryptographicprimitivesthatoperateon fixed sizetexts(blocks). Mostdesigns aim towards secure andfastencryption oflarge amounts ofdata. Block ciphers also serve as the building block of a number of hash functions and message authentication codes(MAC).Thetask of cryptanalysisisto...... ensurethat no attack violatesthe securitybounds specifiedbygeneric attack namely exhaustivekey search and table lookup attacks. This thesis contains a general introduction to cryptography with focus on block ciphers and important block cipher designs, in particular the Advanced Encryption Standard...

  11. Total Spinal Block after Thoracic Paravertebral Block.

    Science.gov (United States)

    Beyaz, Serbülent Gökhan; Özocak, Hande; Ergönenç, Tolga; Erdem, Ali Fuat; Palabıyık, Onur

    2014-02-01

    Thoracic paravertebral block (TPVB) can be performed with or without general anaesthesia for various surgical procedures. TPVB is a popular anaesthetic technique due to its low side effect profile and high analgesic potency. We used 20 mL of 0.5% levobupivacaine for a single injection of unilateral TPVB at the T7 level with neurostimulator in a 63 year old patient with co-morbid disease who underwent cholecystectomy. Following the application patient lost consciousness, and was intubated. Haemodynamic instability was normalised with rapid volume replacement and vasopressors. Anaesthetic drugs were stopped at the end of the surgery and muscle relaxant was antagonised. Return of mucle strenght was shown with neuromuscular block monitoring. Approximately three hours after TPVB, spontaneous breathing started and consciousness returned. A total spinal block is a rare and life-threatening complication. A total spinal block is a complication of spinal anaesthesia, and it can also occur after peripheral blocks. Clinical presentation is characterised by hypotension, bradicardia, apnea, and cardiac arrest. An early diagnosis and appropriate treatment is life saving. In this case report, we want to present total spinal block after TPVB.

  12. Generalized Block Failure

    DEFF Research Database (Denmark)

    Jönsson, Jeppe

    2015-01-01

    Block tearing is considered in several codes as a pure block tension or a pure block shear failure mechanism. However in many situations the load acts eccentrically and involves the transfer of a substantial moment in combination with the shear force and perhaps a normal force. A literature study...... yield lines around the block leads to simple interaction formulas similar to other interaction formulas in the codes.......Block tearing is considered in several codes as a pure block tension or a pure block shear failure mechanism. However in many situations the load acts eccentrically and involves the transfer of a substantial moment in combination with the shear force and perhaps a normal force. A literature study...

  13. BLOCK H-MATRICES AND SPECTRUM OF BLOCK MATRICES

    Institute of Scientific and Technical Information of China (English)

    黄廷祝; 黎稳

    2002-01-01

    The block H-matrices are studied by the concept of G-functions, several concepts of block matrices are introduced. Equivalent characters of block H-matrices are obtained. Spectrum localizations claracterized by Gfunctions for block matrices are got.

  14. The link in Linking

    Science.gov (United States)

    Caldwell, Jane C; Chiale, Pablo A; Gonzalez, Mario D; Baranchuk, Adrian

    2013-01-01

    We present 2 cases of the slow-fast form of AVNRT with initially narrow QRS complexes followed by sudden unexpected transition to persistently wide QRS complexes due to aberrant intraventricular conduction. Introduction of a properly timed extrastimulus in one case and critical oscillations in cycle length due to short-long coupling in the second case set the stage for the initial bundle branch block. However, persistence of the aberrancy pattern once the initial event abated was maintained by the "linking" phenomenon. Delayed, retrograde concealed activation from the contralateral bundle branch perpetuated the initial bundle branch block. PMID:23840106

  15. Block TERM factorization of block matrices

    Institute of Scientific and Technical Information of China (English)

    SHE Yiyuan; HAO Pengwei

    2004-01-01

    Reversible integer mapping (or integer transform) is a useful way to realize Iossless coding, and this technique has been used for multi-component image compression in the new international image compression standard JPEG 2000. For any nonsingular linear transform of finite dimension, its integer transform can be implemented by factorizing the transform matrix into 3 triangular elementary reversible matrices (TERMs) or a series of single-row elementary reversible matrices (SERMs). To speed up and parallelize integer transforms, we study block TERM and SERM factorizations in this paper. First, to guarantee flexible scaling manners, the classical determinant (det) is generalized to a matrix function, DET, which is shown to have many important properties analogous to those of det. Then based on DET, a generic block TERM factorization,BLUS, is presented for any nonsingular block matrix. Our conclusions can cover the early optimal point factorizations and provide an efficient way to implement integer transforms for large matrices.

  16. Blocked Urethral Valves

    Science.gov (United States)

    ... Blocked Urethral Valves Health Issues Listen Español Text Size Email Print Share Blocked Urethral Valves Page Content Article Body Urine leaves the bladder through a tube called the urethra, which in boys passes through the penis. Rarely, small membranes form across the urethra in ...

  17. Types of Heart Block

    Science.gov (United States)

    ... P wave as it normally would. If an electrical signal is blocked before it reaches the ventricles, they won't contract and pump blood to the lungs and the rest of the body. Second-degree heart block is divided into two ...

  18. Related Drupal Nodes Block

    NARCIS (Netherlands)

    Van der Vegt, Wim

    2010-01-01

    Related Drupal Nodes Block This module exposes a block that uses Latent Semantic Analysis (Lsa) internally to suggest three nodes that are relevant to the node a user is viewing. This module performs three tasks. 1) It periodically indexes a Drupal site and generates a Lsa Term Document Matrix. Inde

  19. The Block Neighborhood

    CERN Document Server

    Arrighi, Pablo

    2010-01-01

    We define the block neighborhood of a reversible CA, which is related both to its decomposition into a product of block permutations and to quantum computing. We give a purely combinatorial characterization of the block neighborhood, which helps in two ways. First, it makes the computation of the block neighborhood of a given CA relatively easy. Second, it allows us to derive upper bounds on the block neighborhood: for a single CA as function of the classical and inverse neighborhoods, and for the composition of several CAs. One consequence of that is a characterization of a class of "elementary" CAs that cannot be written as the composition of two simpler parts whose neighborhoods and inverse neighborhoods would be reduced by one half.

  20. Prognosis in patients having the diagnosis of myocardial infarction made during admission to a non-cardiology department

    DEFF Research Database (Denmark)

    Thygesen, Kristian; Saaby, Lotte; Poulsen, Tina Svenstrup

    2013-01-01

    Immediate revascularization is beneficial in patients with presumed new-onset bundle branch block myocardial infarction (BBBMI). In the prehospital setting, it is a challenge to diagnose new-onset BBBMI and triage accordingly.......Immediate revascularization is beneficial in patients with presumed new-onset bundle branch block myocardial infarction (BBBMI). In the prehospital setting, it is a challenge to diagnose new-onset BBBMI and triage accordingly....

  1. Block copolymer battery separator

    Science.gov (United States)

    Wong, David; Balsara, Nitash Pervez

    2016-04-26

    The invention herein described is the use of a block copolymer/homopolymer blend for creating nanoporous materials for transport applications. Specifically, this is demonstrated by using the block copolymer poly(styrene-block-ethylene-block-styrene) (SES) and blending it with homopolymer polystyrene (PS). After blending the polymers, a film is cast, and the film is submerged in tetrahydrofuran, which removes the PS. This creates a nanoporous polymer film, whereby the holes are lined with PS. Control of morphology of the system is achieved by manipulating the amount of PS added and the relative size of the PS added. The porous nature of these films was demonstrated by measuring the ionic conductivity in a traditional battery electrolyte, 1M LiPF.sub.6 in EC/DEC (1:1 v/v) using AC impedance spectroscopy and comparing these results to commercially available battery separators.

  2. Hawaii Census 2000 Blocks

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data layer represents Census 2000 demographic data derived from the PL94-171 redistricting files and SF3. Census geographic entities include blocks, blockgroups...

  3. Steroidal neuromuscular blocking agents

    NARCIS (Netherlands)

    Wierda, JMKH; Mori, K; Ohmura, A; Toyooka, H; Hatano, Y; Shingu, K; Fukuda, K

    1998-01-01

    Since 1964 approximately 20 steroidal neuromuscular blocking agents have been evaluated clinically. Pancuronium, a bisquaternary compound designed on the drawingboard, was the first steroidal relaxant introduced into clinical practice worldwide in the 1970's. Although a major improvement, pancuroniu

  4. Superalloy Lattice Block Structures

    Science.gov (United States)

    Nathal, M. V.; Whittenberger, J. D.; Hebsur, M. G.; Kantzos, P. T.; Krause, D. L.

    2004-01-01

    Initial investigations of investment cast superalloy lattice block suggest that this technology will yield a low cost approach to utilize the high temperature strength and environmental resistance of superalloys in lightweight, damage tolerant structural configurations. Work to date has demonstrated that relatively large superalloy lattice block panels can be successfully investment cast from both IN-718 and Mar-M247. These castings exhibited mechanical properties consistent with the strength of the same superalloys measured from more conventional castings. The lattice block structure also accommodates significant deformation without failure, and is defect tolerant in fatigue. The potential of lattice block structures opens new opportunities for the use of superalloys in future generations of aircraft applications that demand strength and environmental resistance at elevated temperatures along with low weight.

  5. Contaminated soil concrete blocks

    NARCIS (Netherlands)

    Korte, de A.C.J.; Brouwers, H.J.H.; Limbachiya, Mukesh C.; Kew, Hsein Y.

    2009-01-01

    According to Dutch law the contaminated soil needs to be remediated or immobilised. The main focus in this article is the design of concrete blocks, containing contaminated soil, that are suitable for large production, financial feasible and meets all technical and environmental requirements. In ord

  6. Effects of Block Scheduling

    Directory of Open Access Journals (Sweden)

    William R. Veal

    1999-09-01

    Full Text Available This study examined the effects of a tri-schedule on the academic achievement of students in a high school. The tri-schedule consists of traditional, 4x4 block, and hybrid schedules running at the same time in the same high school. Effectiveness of the schedules was determined from the state mandated test of basic skills in reading, language, and mathematics. Students who were in a particular schedule their freshman year were tested at the beginning of their sophomore year. A statistical ANCOVA test was performed using the schedule types as independent variables and cognitive skill index and GPA as covariates. For reading and language, there was no statistically significant difference in test results. There was a statistical difference mathematics-computation. Block mathematics is an ideal format for obtaining more credits in mathematics, but the block format does little for mathematics achievement and conceptual understanding. The results have content specific implications for schools, administrations, and school boards who are considering block scheduling adoption.

  7. Concrete Block Pavements

    Science.gov (United States)

    1983-03-01

    1967, Cedergren 1974, Federal Highway .’,U .. V,47 -’":: 37 Administration 1980). Block pavements have essentially the same prob- lems with moisture...Vicksburg, Miss. Cedergren , H. R. 1974. Drainage of Highway and Airfield Pavements, John Wiley and Sons, New VOk. I Cement and Concrete Association

  8. Block That Pain!

    Science.gov (United States)

    ... along with the National Institute of Dental and Craniofacial Research (NIDCR) and the National Institute of General Medical Sciences (NIGMS). This finding shows that a specific combination of two molecules can block only pain-related neurons. It holds the promise of major ...

  9. Recovery from blocking between outcomes.

    Science.gov (United States)

    Wheeler, Daniel S; Miller, Ralph R

    2005-10-01

    Contemporary associative learning research largely focuses on cue competition phenomena that occur when 2 cues are paired with a common outcome. Little research has been conducted to investigate similar phenomena occurring when a single cue is trained with 2 outcomes. Three conditioned lick suppression experiments with rats assessed whether treatments known to alleviate blocking between cues would also attenuate blocking between outcomes. In Experiment 1, conditioned responding recovered from blocking between outcomes when a long retention interval was interposed between training and testing. Experiment 2 obtained recovery from blocking between outcomes when the blocking outcome was extinguished after the blocking treatment. In Experiment 3, a recovery from blocking between outcomes occurred when a reminder stimulus was presented in a novel context prior to testing. Collectively, these studies demonstrate that blocking of outcomes, like blocking of cues, appears to be caused by a deficit in the expression of an acquired association.

  10. SUPERFICIAL CERVICAL PLEXUS BLOCK

    Directory of Open Access Journals (Sweden)

    Komang Mega Puspadisari

    2014-01-01

    Full Text Available Superficial cervical plexus block is one of the regional anesthesia in  neck were limited to thesuperficial fascia. Anesthesia is used to relieve pain caused either during or after the surgery iscompleted. This technique can be done by landmark or with ultrasound guiding. The midpointof posterior border of the Sternocleidomastoid was identified and the prosedure done on thatplace or on the level of cartilage cricoid.

  11. Managing access block.

    Science.gov (United States)

    Cameron, Peter; Scown, Paul; Campbell, Donald

    2002-01-01

    There is pessimism regarding the ability of the Acute Health Sector to manage access block for emergency and elective patients. Melbourne Health suffered an acute bed crisis in 2001 resulting in record ambulance diversions and emergency department (ED) delays. We conducted an observational study to reduce access block for emergency patients whilst maintaining elective throughput at Melbourne Health. This involved a clinician-led taskforce using previously proven principles for organisational change to implement 51 actions to improve patient access over a three-month period. The primary outcome measures were ambulance diversion, emergency patients waiting more than 12 hours for an inpatient bed, elective throughput and theatre cancellations. Despite a reduction in multi-day bed numbers all primary objectives were met, ambulance diversion decreased to minimal levels, 12-hour waits decreased by 40% and elective throughput was maintained. Theatre cancellations were also minimised. We conclude that access block can be improved by clinician-led implementation of proven process improvements over a short time frame. The ability to sustain change over the longer term requires further study.

  12. Block Transfer Handbook: Constructing and Negotiating Block Transfer Agreements.

    Science.gov (United States)

    Finlay, Finola

    The purpose of this handbook is to provide resources for institutions or articulation committees who are engaged in the task of investigating the feasibility of block transfer agreements. Block transfer is the process whereby a block of credits is granted to students who have successfully completed a certificate, diploma, or cluster of courses…

  13. Demographic Data - MDC_Block

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — A polygon feature class of Miami-Dade Census 2000 Blocks. Census blocks are areas bounded on all sides by visible and/or invisible features shown on a map prepared...

  14. Habitat Blocks and Wildlife Corridors

    Data.gov (United States)

    Vermont Center for Geographic Information — Habitat blocks are areas of contiguous forest and other natural habitats that are unfragmented by roads, development, or agriculture. Vermonts habitat blocks are...

  15. Porous block nanofiber composite filters

    Energy Technology Data Exchange (ETDEWEB)

    Ginley, David S.; Curtis, Calvin J.; Miedaner, Alexander; Weiss, Alan J.; Paddock, Arnold

    2016-08-09

    Porous block nano-fiber composite (110), a filtration system (10) and methods of using the same are disclosed. An exemplary porous block nano-fiber composite (110) includes a porous block (100) having one or more pores (200). The porous block nano-fiber composite (110) also includes a plurality of inorganic nano-fibers (211) formed within at least one of the pores (200).

  16. Properties of blocked linear systems.

    Science.gov (United States)

    Chen, Weitian; Anderson, Brian D O; Deistler, Manfred; Filler, Alexander

    2012-10-01

    This paper presents a systematic study on the properties of blocked linear systems that have resulted from blocking discrete-time linear time invariant systems. The main idea is to explore the relationship between the blocked and the unblocked systems. Existing results are reviewed and a number of important new results are derived. Focus is given particularly on the zero properties of the blocked system as no such study has been found in the literature.

  17. Appropriate schemata and building blocks

    Institute of Scientific and Technical Information of China (English)

    Yang Haijun; Li Minqiang

    2005-01-01

    Appropriate schemata as a novel concept to characterize building blocks are introduced, and then, the traits of appropriate schemata are presented. The effects of building blocks by search operators are analyzed. Hence, the experiments on RR-8X8 are employed to verify that appropriate schemata construct the building blocks. The validity of appropriate schemata and building blocks from the views of theory and practice is presented.

  18. Blocking the Hawking radiation

    DEFF Research Database (Denmark)

    Autzen, M.; Kouvaris, C.

    2014-01-01

    grows after its formation (and eventually destroys the star) instead of evaporating. The fate of the black hole is dictated by the two opposite mechanics, i.e., accretion of nuclear matter from the center of the star and Hawking radiation that tends to decrease the mass of the black hole. We study how...... the assumptions for the accretion rate can in fact affect the critical mass beyond which a black hole always grows. We also study to what extent degenerate nuclear matter can impede Hawking radiation due to the fact that emitted particles can be Pauli blocked at the core of the star....

  19. Property Blocks: Games and Activities.

    Science.gov (United States)

    Humphreys, Alan, Ed.; Dailey, Jean, Ed.

    This pamphlet describes the property blocks produced by MINNEMAST, and discusses their use in the development of thinking processes. Classification systems, including block diagrams and tree diagrams, are discussed. Sixteen classroom activities and eleven games which use the blocks are described. Suggestions to the teacher for further reading are…

  20. Humanoid by ROBO-BLOCK

    Science.gov (United States)

    Niimi, Hirofumi; Koike, Minoru; Takeuchi, Seiichi; Douhara, Noriyoshi

    2007-12-01

    Humanoid by ROBO-BLOCK (robot block system) and the rational formula of robots were proposed. ROBO-BLOCK is composed of servo motors, the parts for servomotor rotor, the brackets for servomotor fixation, the board parts and the controllers. A robot can be assembled easily by ROBO-BLOCK. Meanwhile, it is convenient when the structure of the robot can be described easily as a character. The whole structure of the robot is expressed as rational formula of the robot to show molecule structure in chemistry. ROBO-BLOCK can be useful for not only the research but also the education. Creative student experiment was done in the college of industrial technology.

  1. Spintronics: Conceptual Building Blocks

    Science.gov (United States)

    Ansermet, J.-Ph.

    The purpose of this introduction to spintronics is to provide some elementary description of its conceptual building blocks. Thus, it is intended for a newcomer to the field. After recalling rudimentary descriptions of spin precession and spin relaxation, spin-dependent transport is treated within the Boltzmann formalism. This suffices to introduce key notions such as the spin asymmetry of the conductivities in the two-current model, the spin diffusion length, and spin accumulation. Two basic mechanisms of spin relaxation are then presented, one arising from spin-orbit scattering and the other from electron-magnon collisions. Finally, the action of a spin-polarized current on magnetization is presented in a thermodynamics framework. This introduces the notion of spin torque and the characteristic length scale over which the transverse spin polarization of conduction electron decays as it is injected into a magnet.

  2. Photovoltaic building blocks

    DEFF Research Database (Denmark)

    Hanberg, Peter Jesper; Jørgensen, Anders Michael

    2014-01-01

    it directcompetitive with fossil energy sources a further reduction is needed. By increasing the efficiency of the solar cells one gain an advantage through the whole chain of cost. So that per produced Watt of power less material is spent, installation costs are lower, less area is used etc. With an average...... efficiency of about 15% for commercial Silicon solar cells there is still much to gain. DTU Danchip provides research facilities, equipment and expertise for the building blocks that comprises fabricating the efficient solar cell. In order to get more of the sun light into the device we provide thin film......Photovoltaics (PV), better known as solar cells, are now a common day sight on many rooftops in Denmark.The installed capacity of PV systems worldwide is growing exponentially1 and is the third most importantrenewable energy source today. The cost of PV is decreasing fast with ~10%/year but to make...

  3. Celiac ganglia block

    Energy Technology Data Exchange (ETDEWEB)

    Akinci, Devrim [Department of Radiology, Hacettepe University School of Medicine, Sihhiye, 06100 Ankara (Turkey); Akhan, Okan [Department of Radiology, Hacettepe University School of Medicine, Sihhiye, 06100 Ankara (Turkey)]. E-mail: oakhan@hacettepe.edu.tr

    2005-09-01

    Pain occurs frequently in patients with advanced cancers. Tumors originating from upper abdominal viscera such as pancreas, stomach, duodenum, proximal small bowel, liver and biliary tract and from compressing enlarged lymph nodes can cause severe abdominal pain, which do not respond satisfactorily to medical treatment or radiotherapy. Percutaneous celiac ganglia block (CGB) can be performed with high success and low complication rates under imaging guidance to obtain pain relief in patients with upper abdominal malignancies. A significant relationship between pain relief and degree of tumoral celiac ganglia invasion according to CT features was described in the literature. Performing the procedure in the early grades of celiac ganglia invasion on CT can increase the effectiveness of the CGB, which is contrary to World Health Organization criteria stating that CGB must be performed in patients with advanced stage cancer. CGB may also be effectively performed in patients with chronic pancreatitis for pain palliation.

  4. Atomic Basic Blocks

    Science.gov (United States)

    Scheler, Fabian; Mitzlaff, Martin; Schröder-Preikschat, Wolfgang

    Die Entscheidung, einen zeit- bzw. ereignisgesteuerten Ansatz für ein Echtzeitsystem zu verwenden, ist schwierig und sehr weitreichend. Weitreichend vor allem deshalb, weil diese beiden Ansätze mit äußerst unterschiedlichen Kontrollflussabstraktionen verknüpft sind, die eine spätere Migration zum anderen Paradigma sehr schwer oder gar unmöglich machen. Wir schlagen daher die Verwendung einer Zwischendarstellung vor, die unabhängig von der jeweils verwendeten Kontrollflussabstraktion ist. Für diesen Zweck verwenden wir auf Basisblöcken basierende Atomic Basic Blocks (ABB) und bauen darauf ein Werkzeug, den Real-Time Systems Compiler (RTSC) auf, der die Migration zwischen zeit- und ereignisgesteuerten Systemen unterstützt.

  5. Large Block Test Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Lin, W

    2001-12-01

    This report documents the Large-Block Test (LBT) conducted at Fran Ridge near Yucca Mountain, Nevada. The LBT was a thermal test conducted on an exposed block of middle non-lithophysal Topopah Spring tuff (Tptpmn) and was designed to assist in understanding the thermal-hydrological-mechanical-chemical (THMC) processes associated with heating and then cooling a partially saturated fractured rock mass. The LBT was unique in that it was a large (3 x 3 x 4.5 m) block with top and sides exposed. Because the block was exposed at the surface, boundary conditions on five of the six sides of the block were relatively well known and controlled, making this test both easier to model and easier to monitor. This report presents a detailed description of the test as well as analyses of the data and conclusions drawn from the test. The rock block that was tested during the LBT was exposed by excavation and removal of the surrounding rock. The block was characterized and instrumented, and the sides were sealed and insulated to inhibit moisture and heat loss. Temperature on the top of the block was also controlled. The block was heated for 13 months, during which time temperature, moisture distribution, and deformation were monitored. After the test was completed and the block cooled down, a series of boreholes were drilled, and one of the heater holes was over-cored to collect samples for post-test characterization of mineralogy and mechanical properties. Section 2 provides background on the test. Section 3 lists the test objectives and describes the block site, the site configuration, and measurements made during the test. Section 3 also presents a chronology of events associated with the LBT, characterization of the block, and the pre-heat analyses of the test. Section 4 describes the fracture network contained in the block. Section 5 describes the heating/cooling system used to control the temperature in the block and presents the thermal history of the block during the test

  6. Dimensional Reduction for Conformal Blocks

    CERN Document Server

    Hogervorst, Matthijs

    2016-01-01

    We consider the dimensional reduction of a CFT, breaking multiplets of the d-dimensional conformal group SO(d+1,1) up into multiplets of SO(d,1). This leads to an expansion of d-dimensional conformal blocks in terms of blocks in d-1 dimensions. In particular, we obtain a formula for 3d conformal blocks as an infinite sum over 2F1 hypergeometric functions with closed-form coefficients.

  7. Common blocks for ASQS(12

    Directory of Open Access Journals (Sweden)

    Lorenzo Milazzo

    1997-05-01

    Full Text Available An ASQS(v is a particular Steiner system featuring a set of v vertices and two separate families of blocks, B and G, whose elements have a respective cardinality of 4 and 6. It has the property that any three vertices of X belong either to a B-block or to a G-block. The parameter cb is the number of common blocks in two separate ASQSs, both defined on the same set of vertices X . In this paper it is shown that cb ≤ 29 for any pair of ASQSs(12.

  8. Eikonalization of Conformal Blocks

    CERN Document Server

    Fitzpatrick, A Liam; Walters, Matthew T; Wang, Junpu

    2015-01-01

    Classical field configurations such as the Coulomb potential and Schwarzschild solution are built from the $t$-channel exchange of many light degrees of freedom. We study the CFT analog of this phenomenon, which we term the `eikonalization' of conformal blocks. We show that when an operator $T$ appears in the OPE $\\mathcal{O}(x) \\mathcal{O}(0)$, then the large spin $\\ell$ Fock space states $[TT \\cdots T]_{\\ell}$ also appear in this OPE with a computable coefficient. The sum over the exchange of these Fock space states in an $\\langle \\mathcal{O} \\mathcal{O} \\mathcal{O} \\mathcal{O} \\rangle$ correlator build the classical `$T$ field' in the dual AdS description. In some limits the sum of all Fock space exchanges can be represented as the exponential of a single $T$ exchange in the 4-pt correlator of $\\mathcal{O}$. Our results should be useful for systematizing $1/\\ell$ perturbation theory in general CFTs and simplifying the computation of large spin OPE coefficients. As examples we obtain the leading $\\log \\ell$...

  9. Adductor Canal Block versus Femoral Nerve Block and Quadriceps Strength

    DEFF Research Database (Denmark)

    Jæger, Pia Therese; Nielsen, Zbigniew Jerzy Koscielniak; Henningsen, Lene Marianne;

    2013-01-01

    : The authors hypothesized that the adductor canal block (ACB), a predominant sensory blockade, reduces quadriceps strength compared with placebo (primary endpoint, area under the curve, 0.5-6 h), but less than the femoral nerve block (FNB; secondary endpoint). Other secondary endpoints were...

  10. Block Transfer Agreement Evaluation Project

    Science.gov (United States)

    Bastedo, Helena

    2010-01-01

    The objective of this project is to evaluate for the British Columbia Council on Admissions and Transfer (BCCAT) the effectiveness of block transfer agreements (BTAs) in the BC Transfer System and recommend steps to be taken to improve their effectiveness. Findings of this study revealed that institutions want to expand block credit transfer;…

  11. Four-block beam collimator

    CERN Multimedia

    1977-01-01

    The photo shows a four-block collimator installed on a control table for positioning the alignment reference marks. Designed for use with the secondary beams, the collimators operated in vacuum conditions. The blocks were made of steel and had a standard length of 1 m. The maximum aperture had a square coss-section of 144 cm2. (See Annual Report 1976.)

  12. OPAL Various Lead Glass Blocks

    CERN Multimedia

    These lead glass blocks were part of a CERN detector called OPAL (one of the four experiments at the LEP particle detector). OPAL uses some 12 000 blocks of glass like this to measure particle energies in the electromagnetic calorimeter. This detector measured the energy deposited when electrons and photons were slowed down and stopped.

  13. Block storage subsystem performance analysis

    CERN Document Server

    CERN. Geneva

    2016-01-01

    You feel that your service is slow because of the storage subsystem? But there are too many abstraction layers between your software and the raw block device for you to debug all this pile... Let's dive on the platters and check out how the block storage sees your I/Os! We can even figure out what those patterns are meaning.

  14. Conformal Nets II: Conformal Blocks

    Science.gov (United States)

    Bartels, Arthur; Douglas, Christopher L.; Henriques, André

    2017-03-01

    Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

  15. COMPARISON IN THE SAME PATIENT OF ABERRANT CONDUCTION AND BUNDLE-BRANCH REENTRY AFTER DOFETILIDE, A NEW SELECTIVE CLASS-III ANTIARRHYTHMIC AGENT

    NARCIS (Netherlands)

    CRIJNS, HJGM; KINGMA, JH; GOSSELINK, ATM; LIE, K

    1993-01-01

    Dofetilide may induce aberrant intraventricular conduction due to its Class III effect. This report describes an atrial fibrillation patient in whom intraventricular conduction was studied before and after dofetilide using multiple endocardial recordings. Dofetilide provoked aberrant conduction duri

  16. MarineMineralsProgramBlocks

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains OCS block outlines and delineated polygons in ESRI ArcGIS shape file format for the BOEM Gulf of Mexico Region that contain sediment resources...

  17. Hawaii Census 2000 Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data layer represents Census 2000 demographic data derived from the PL94-171 redistricting files and SF3. Census geographic entities include blocks, blockgroups...

  18. Multi-block and path modelling procedures

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    2008-01-01

    The author has developed a unified theory of path and multi-block modelling of data. The data blocks are arranged in a directional path. Each data block can lead to one or more data blocks. It is assumed that there is given a collection of input data blocks. Each of them is supposed to describe one...

  19. NANOSTRUCTURES OF FUNCTIONAL BLOCK COPOLYMERS

    Institute of Scientific and Technical Information of China (English)

    Guojun Liu

    2000-01-01

    Nanostructure fabrication from block copolymers in my group normally involves polymer design, synthesis, selfassembly, selective domain crosslinking, and sometimes selective domain removal. Preparation of thin films with nanochannels was used to illustrate the strategy we took. In this particular case, a linear triblock copolymer polyisopreneblock-poly(2-cinnamoylethyl methacrylate)-block-poly(t-butyl acrylate), PI-b-PCEMA-b-PtBA, was used. Films, 25 to50μm thick, were prepared from casting on glass slides a toluene solution of PI-b-PCEMA-b-PtBA and PtBA homopolymer,hPtBA, where hPtBA is shorter than the PtBA block. At the hPtBA mass fraction of 20% relative to the triblock or the total PtBA (hPtBA and PtBA block) volume fraction of 0.44, hPtBA and PtBA formed a seemingly continuous phase in the matrix of PCEMA and PI. Such a block segregation pattern was locked in by photocrosslinking the PCEMA domain. Nanochannels were formed by extracting out hPtBA with solvent. Alternatively, larger channels were obtained from extracting out hPtBA and hydrolyzing the t-butyl groups of the PtBA block. Such membranes were not liquid permeable but had gas permeability constants ~6 orders of magnitude higher than that of low-density polyethylene films.

  20. Skin delivery by block copolymer nanoparticles (block copolymer micelles).

    Science.gov (United States)

    Laredj-Bourezg, Faiza; Bolzinger, Marie-Alexandrine; Pelletier, Jocelyne; Valour, Jean-Pierre; Rovère, Marie-Rose; Smatti, Batoule; Chevalier, Yves

    2015-12-30

    Block copolymer nanoparticles often referred to as "block copolymer micelles" have been assessed as carriers for skin delivery of hydrophobic drugs. Such carriers are based on organic biocompatible and biodegradable materials loaded with hydrophobic drugs: poly(lactide)-block-poly(ethylene glycol) copolymer (PLA-b-PEG) nanoparticles that have a solid hydrophobic core made of glassy poly(d,l-lactide), and poly(caprolactone)-block-poly(ethylene glycol) copolymer (PCL-b-PEG) nanoparticles having a liquid core of polycaprolactone. In vitro skin absorption of all-trans retinol showed a large accumulation of retinol in stratum corneum from both block copolymer nanoparticles, higher by a factor 20 than Polysorbate 80 surfactant micelles and by a factor 80 than oil solution. Additionally, skin absorption from PLA-b-PEG nanoparticles was higher by one order of magnitude than PCL-b-PEG, although their sizes (65nm) and external surface (water-swollen PEG layer) were identical as revealed by detailed structural characterizations. Fluorescence microscopy of histological skin sections provided a non-destructive picture of the storage of Nile Red inside stratum corneum, epidermis and dermis. Though particle cores had a different physical states (solid or liquid as measured by (1)H NMR), the ability of nanoparticles for solubilization of the drug assessed from their Hildebrand solubility parameters appeared the parameter of best relevance regarding skin absorption.

  1. Optimal Backward Perturbation Analysis for the Block Skew Circulant Linear Systems with Skew Circulant Blocks

    Directory of Open Access Journals (Sweden)

    Zhaolin Jiang

    2014-01-01

    Full Text Available We first give the block style spectral decomposition of arbitrary block skew circulant matrix with skew circulant blocks. Secondly, we obtain the singular value of block skew circulant matrix with skew circulant blocks as well. Finally, based on the block style spectral decomposition, we deal with the optimal backward perturbation analysis for the block skew circulant linear system with skew circulant blocks.

  2. Contrasting reduced overshadowing and blocking.

    Science.gov (United States)

    Wheeler, Daniel S; Miller, Ralph R

    2007-07-01

    Preexposure of a cue without an outcome (X-) prior to compound pairings with the outcome (XZ-->O) can reduce overshadowing of a target cue (Z). Moreover, pairing a cue with an outcome (X-->O) before compound training can enhance its ability to compete with another cue (i.e., blocking). Four experiments were conducted in a conditioned bar-press suppression preparation with rats to determine whether spacing of the X- or X-->O trials would differentially affect reduced overshadowing and blocking. Experiment 1a showed that reduced overshadowing was larger with massed trials than with spaced trials. Experiment 1b found that blocking was larger with spaced trials than with massed trials. Experiments 2a and 2b indicated that these effects of trial spacing were both mediated by the associative status of the context at test. The results are interpreted in the framework of contemporary learning theories.

  3. Diversity Gain through Antenna Blocking

    Directory of Open Access Journals (Sweden)

    V. Dehghanian

    2012-01-01

    Full Text Available As part of the typical usage mode, interaction between a handheld receiver antenna and the operator's RF absorbing body and nearby objects is known to generate variability in antenna radiation characteristics through blocking and pattern changes. It is counterintuitive that random variations in blocking can result in diversity gain of practical applicability. This diversity gain is quantified from a theoretical and experimental perspective. Measurements carried out at 1947.5 MHz verify the theoretical predictions, and a diversity gain of 3.1 dB was measured through antenna blocking and based on the utilized measurement setup. The diversity gain can be exploited to enhance signal detectability of handheld receivers based on a single antenna in indoor multipath environments.

  4. Block ground interaction of rockfalls

    Science.gov (United States)

    Volkwein, Axel; Gerber, Werner; Kummer, Peter

    2016-04-01

    During a rockfall the interaction of the falling block with the ground is one of the most important factors that define the evolution of a rockfall trajectory. It steers the rebound, the rotational movement, possibly brake effects, friction losses and damping effects. Therefore, if most reliable rockfall /trajectory simulation software is sought a good understanding of the block ground interaction is necessary. Today's rockfall codes enable the simulation of a fully 3D modelled block within a full 3D surface . However, the details during the contact, i.e. the contact duration, the penetration depth or the dimension of the marks in the ground are usually not part of the simulation. Recent field tests with rocks between 20 and 80 kg have been conducted on a grassy slope in 2014 [1]. A special rockfall sensor [2] within the blocks measured the rotational velocity and the acting accelerations during the tests. External video records and a so-called LocalPositioningSystem deliver information on the travel velocity. With these data not only the flight phases of the trajectories but also the contacts with the ground can be analysed. During the single jumps of a block the flight time, jump length, the velocity, and the rotation are known. During the single impacts their duration and the acting accelerations are visible. Further, the changes of rotational and translational velocity influence the next jump of the block. The change of the rotational velocity over the whole trajectory nicely visualizes the different phases of a rockfall regarding general acceleration and deceleration in respect to the inclination and the topography of the field. References: [1] Volkwein A, Krummenacher B, Gerber W, Lardon J, Gees F, Brügger L, Ott T (2015) Repeated controlled rockfall trajectory testing. [Abstract] Geophys. Res. Abstr. 17: EGU2015-9779. [2] Volkwein A, Klette J (2014) Semi-Automatic Determination of Rockfall Trajectories. Sensors 14: 18187-18210.

  5. OPAL 96 Blocks Lead Glass

    CERN Multimedia

    This array of 96 lead glass bricks formed part of the OPAL electromagnetic calorimeter. One half of the complete calorimeter is shown in the picture above. There were 9440 lead glass counters in the OPAL electromagnetic calorimeter. These are made of Schott type SF57 glass and each block weighs about 25 kg and consists of 76% PbO by weight. Each block has a Hamamatsu R2238 photomultiplier glued on to it. The complete detector was in the form of a cylinder 7m long and 6m in diameter. It was used to measure the energy of electrons and photons produced in LEP interactions.

  6. Sympathetic blocks for visceral cancer pain management

    DEFF Research Database (Denmark)

    Mercadante, Sebastiano; Klepstad, Pal; Kurita, Geana Paula

    2015-01-01

    The neurolytic blocks of sympathetic pathways, including celiac plexus block (CPB) and superior hypogastric plexus block (SHPB) , have been used for years. The aim of this review was to assess the evidence to support the performance of sympathetic blocks in cancer patients with abdominal visceral...

  7. Scattering matrices with block symmetries

    OpenAIRE

    Życzkowski, Karol

    1997-01-01

    Scattering matrices with block symmetry, which corresponds to scattering process on cavities with geometrical symmetry, are analyzed. The distribution of transmission coefficient is computed for different number of channels in the case of a system with or without the time reversal invariance. An interpolating formula for the case of gradual time reversal symmetry breaking is proposed.

  8. Architectures for block Toeplitz systems

    NARCIS (Netherlands)

    Bouras, Ilias; Glentis, George-Othon; Kalouptsidis, Nicholas

    1996-01-01

    In this paper efficient VLSI architectures of highly concurrent algorithms for the solution of block linear systems with Toeplitz or near-to-Toeplitz entries are presented. The main features of the proposed scheme are the use of scalar only operations, multiplications/divisions and additions, and th

  9. Building Blocks for Personal Brands

    Science.gov (United States)

    Thomas, Lisa Carlucci

    2011-01-01

    In this article, the author discusses the four essential building blocks for personal brands: (1) name; (2) message; (3) channels; and (4) bridges. However, outstanding building materials can only take a person so far. The author emphasizes that vision, determination, faith, a sense of humor, and humility are also required.

  10. First Degree Pacemaker Exit Block

    Directory of Open Access Journals (Sweden)

    Johnson Francis

    2016-10-01

    Full Text Available Usually atrial and ventricular depolarizations follow soon after the pacemaker stimulus (spike on the ECG. But there can be an exit block due to fibrosis at the electrode - tissue interface at the lead tip. This can increase the delay between the spike and atrial or ventricular depolarization.

  11. Pourfour Du Petit syndrome after interscalene block.

    Science.gov (United States)

    Santhosh, Mysore Chandramouli Basappji; Pai, Rohini B; Rao, Raghavendra P

    2013-04-01

    Interscalene block is commonly associated with reversible ipsilateral phrenic nerve block, recurrent laryngeal nerve block, and cervical sympathetic plexus block, presenting as Horner's syndrome. We report a very rare Pourfour Du Petit syndrome which has a clinical presentation opposite to that of Horner's syndrome in a 24-year-old male who was given interscalene block for open reduction and internal fixation of fracture upper third shaft of left humerus.

  12. Endoscopic sphenopalatine ganglion block for pain relief

    OpenAIRE

    Murty, P. S. N.; Prasanna, Atma

    1998-01-01

    The anaesthetic effect of the sphenopalatine (SPG) block has been well utilized for intranasal topical anaesthesia but the analgesic efficacy of (SPG) block, though well documented in literature, has not been put into practice. The methods available for SPG block till date were blind as they do not visualize the foramen. Nasal endoscopies have been used to visualize the foramen for an effective block. The authors present their experience with the endoscopic sphenopalatine ganglion block for p...

  13. Pourfour Du Petit syndrome after interscalene block

    Directory of Open Access Journals (Sweden)

    Mysore Chandramouli Basappji Santhosh

    2013-01-01

    Full Text Available Interscalene block is commonly associated with reversible ipsilateral phrenic nerve block, recurrent laryngeal nerve block, and cervical sympathetic plexus block, presenting as Horner′s syndrome. We report a very rare Pourfour Du Petit syndrome which has a clinical presentation opposite to that of Horner′s syndrome in a 24-year-old male who was given interscalene block for open reduction and internal fixation of fracture upper third shaft of left humerus.

  14. Limiting Spectral Distribution of Block Matrices with Toeplitz Block Structure

    CERN Document Server

    Basu, Riddhipratim; Ganguly, Shirshendu; Hazra, Rajat Subhra

    2011-01-01

    We study two specific symmetric random block Toeplitz (of dimension $k \\times k$) matrices: where the blocks (of size $n \\times n$) are (i) matrices with i.i.d. entries, and (ii) asymmetric Toeplitz matrices. Under suitable assumptions on the entries, their limiting spectral distributions (LSDs) exist (after scaling by $\\sqrt{nk}$) when (a) $k$ is fixed and $n \\to\\infty$ (b) $n$ is fixed and $k\\rightarrow \\infty$ (c) $n$ and $k$ go to $\\infty$ simultaneously. Further the LSD's obtained in (a) and (b) coincide with those in (c) when $n$ or respectively $k$ tends to infinity. This limit in (c) is the semicircle law in case (i). In Case (ii) the limit is related to the limit of the random symmetric Toepiltz matrix as obtained by Bryc et al.(2006) and Hammond and Miller(2005).

  15. On the Eigenvalues and Eigenvectors of Block Triangular Preconditioned Block Matrices

    KAUST Repository

    Pestana, Jennifer

    2014-01-01

    Block lower triangular matrices and block upper triangular matrices are popular preconditioners for 2×2 block matrices. In this note we show that a block lower triangular preconditioner gives the same spectrum as a block upper triangular preconditioner and that the eigenvectors of the two preconditioned matrices are related. © 2014 Society for Industrial and Applied Mathematics.

  16. Graphs obtained from collections of blocks

    Directory of Open Access Journals (Sweden)

    Colton Magnant

    2015-03-01

    Full Text Available Given a collection of $d$-dimensional rectangular solids called blocks, no two of which sharing interior points, construct a block graph by adding a vertex for each block and an edge if the faces of the two corresponding blocks intersect nontrivially.  It is known that if $d \\geq 3$, such block graphs can have arbitrarily large chromatic number.  We prove that the chromatic number can be bounded with only a mild restriction on the sizes of the blocks.  We also show that block graphs of block configurations arising from partitions of $d$-dimensional hypercubes into sub-hypercubes are at least $d$-connected.  Bounds on the diameter and the hamiltonicity of such block graphs are also discussed.

  17. A conformal block Farey tail

    CERN Document Server

    Maloney, Alexander; Ng, Gim Seng

    2016-01-01

    We investigate the constraints of crossing symmetry on CFT correlation functions. Four point conformal blocks are naturally viewed as functions on the upper-half plane, on which crossing symmetry acts by PSL(2,Z) modular transformations. This allows us to construct a unique, crossing symmetric function out of a given conformal block by averaging over PSL(2,Z). In some two dimensional CFTs the correlation functions are precisely equal to the modular average of the contributions of a finite number of light states. For example, in the two dimensional Ising and tri-critical Ising model CFTs, the correlation functions of identical operators are equal to the PSL(2,Z) average of the Virasoro vacuum block; this determines the 3 point function coefficients uniquely in terms of the central charge. The sum over PSL(2,Z) in CFT2 has a natural AdS3 interpretation as a sum over semi-classical saddle points, which describe particles propagating along rational tangles in the bulk. We demonstrate this explicitly for the corre...

  18. Hillslope-derived blocks retard river incision

    Science.gov (United States)

    Shobe, Charles M.; Tucker, Gregory E.; Anderson, Robert S.

    2016-05-01

    The most common detachment-limited river incision models ignore the effects of sediment on fluvial erosion, yet steep reaches of mountain rivers often host clusters of large (>1 m) blocks. We argue that this distribution of blocks is a manifestation of an autogenic negative feedback in which fast vertical river incision steepens adjacent hillslopes, which deliver blocks to the channel. Blocks inhibit incision by shielding the bed and enhancing form drag. We explore this feedback with a 1-D channel-reach model in which block delivery by hillslopes depends on the river incision rate. Results indicate that incision-dependent block delivery can explain the block distribution in Boulder Creek, Colorado. The proposed negative feedback may significantly slow knickpoint retreat, channel adjustment, and landscape response compared to rates predicted by current theory. The influence of hillslope-derived blocks may complicate efforts to extract base level histories from river profiles.

  19. Demographic Data - MDC_BlockGroup

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — A polygon feature class of Miami-Dade County Census 2000 Block Groups. A census Block Group is a statistical subdivision of a census Tract consisting of a cluster...

  20. Slickenside developed in chert block

    Science.gov (United States)

    Ando, J.; Hayasaka, Y.; Nishiwaki, T.

    2011-12-01

    We observe the microstructures of slickenside developed in chert block mainly with a TEM, in order to clarify generation mechanism of the slickenside. This chert block occurs in the Jurassic accretionary complex in eastern Yamaguchi Prefecture, Japan. The complex, chaotic sediment, is composed of allochthonous blocks, mainly of chert, limestone, sandstone and mudstone in the argillaceous matrix. The color of the undeformed chert is pale blue to white, while the surface of slickenside is black. The stereo microscopy indicates the top surface of slickenside is covered with a transparent material, whose composition is mainly Si, measured by EPMA. The striation is well developed on the transparent-Si-material. We made thin sections, parallel and perpendicular to striation and slickenside, respectively. On the thin sections, the elongated quartz grains are oriented obliquely to the slickenside with 20-30 degree. Many fluid inclusions, which represent healed microcracks, are observed within the quartz grains. These quartz grains show strong undulose extinction and bulging-recrystallization. Apatite grains are also observed as a main constituent mineral. We made TEM foils from the above thin section by FIB. TEM observation indicates the amorphous layer with several ten nanometers in width distributes along the slickenside. (We speculate the most part of the amorphous layer are taken away during polishing of the thin section, because the strength of the amorphous layer is weak. Therefore we now make thin section again with care.) The tangled dislocations are developed within the quartz grains. They make subgrains with ca. 1 micrometer in size. These results suggest the slickenside was generated by the frictional melting of quartz grains on slip plane under very high stress condition, same as pseudotachylyte.

  1. Practical Binary Adaptive Block Coder

    CERN Document Server

    Reznik, Yuriy A

    2007-01-01

    This paper describes design of a low-complexity algorithm for adaptive encoding/ decoding of binary sequences produced by memoryless sources. The algorithm implements universal block codes constructed for a set of contexts identified by the numbers of non-zero bits in previous bits in a sequence. We derive a precise formula for asymptotic redundancy of such codes, which refines previous well-known estimate by Krichevsky and Trofimov, and provide experimental verification of this result. In our experimental study we also compare our implementation with existing binary adaptive encoders, such as JBIG's Q-coder, and MPEG AVC (ITU-T H.264)'s CABAC algorithms.

  2. New Considerations of Turbo Block Codes

    Institute of Scientific and Technical Information of China (English)

    YUEDianwu; EdSHWEDYK

    2004-01-01

    It is shown that (1) a general linear systematic block code can be expressed as a turbo block code and therefore can be decoded using any turbo decoding algorithm; (2) a turbo block code can be also encoded and decoded without any interleaver with the same performance as when an interleaver is present.

  3. Writer's block in a Chinese sample.

    Science.gov (United States)

    Lee, Sy-Ying; Krashen, Stephen

    2003-10-01

    To assess whether writer's block occurs in languages other than English, a Chinese language translation of Rose's Writer's Block questionnaire was administered to 98 university students in Taiwan. Analysis suggests that writer's block occurs for Chinese students, and, as in English, it is related to premature editing and to a lack of strategies for dealing with complex writing tasks.

  4. Micellization and Dynamics of a Block Copolymer

    DEFF Research Database (Denmark)

    Hvidt, Søren

    2006-01-01

    Triblock copolymers of the type EPE, where E and P denote ethylene oxide and propylene oxide blocks, respectively, are industrially important copolymers often called Pluronics or Poloxamers. EPE copolymers form micelles with a core of P blocks and different micellar shapes depending on block leng...

  5. Cutaneous Sensory Block Area, Muscle-Relaxing Effect, and Block Duration of the Transversus Abdominis Plane Block

    DEFF Research Database (Denmark)

    Støving, Kion; Rothe, Christian; Rosenstock, Charlotte V

    2015-01-01

    into a medial and lateral part by a vertical line through the anterior superior iliac spine. We measured muscle thickness of the 3 lateral abdominal muscle layers with ultrasound in the relaxed state and during maximal voluntary muscle contraction. The volunteers reported the duration of the sensory block...... and the abdominal muscle-relaxing effect. RESULTS: The lateral part of the cutaneous sensory block area was a median of 266 cm2 (interquartile range, 191-310 cm2) and the medial part 76 cm 2(interquartile range, 54-127 cm2). In all the volunteers, lateral wall muscle thickness decreased significantly by 9.2 mm (6......BACKGROUND AND OBJECTIVES: The transversus abdominis plane (TAP) block is a widely used nerve block. However, basic block characteristics are poorly described. The purpose of this study was to assess the cutaneous sensory block area, muscle-relaxing effect, and block duration. METHODS: Sixteen...

  6. Seismicity of the Jalisco Block

    Science.gov (United States)

    Nunez-Cornu, F. J.; Rutz, M.; Camarena-Garcia, M.; Trejo-Gomez, E.; Reyes-Davila, G.; Suarez-Plascencia, C.

    2002-12-01

    In April 2002 began to transmit the stations of the first phase of Jalisco Telemetric Network located at the northwest of Jalisco Block and at the area of Volcan de Fuego (Colima Volcano), in June were deployed four additional MarsLite portable stations in the Bahia de Banderas area, and by the end of August one more portable station at Ceboruco Volcano. The data of these stations jointly with the data from RESCO (Colima Telemetric Network) give us the minimum seismic stations coverage to initiate in a systematic and permanent way the study of the seismicity in this very complex tectonic region. A preliminary analysis of seismicity based on the events registered by the networks using a shutter algorithm, confirms several important features proposed by microseismicity studies carried out between 1996 and 1998. A high level of seismicity inside and below of Rivera plate is observed, this fact suggest a very complex stress pattern acting on this plate. Shallow seismicity at south and east of Bahia de Banderas also suggest a complex stress pattern in this region of the Jalisco Block, events at more than 30 km depth are located under the mouth of the bay and in face of it, a feature denominated Banderas Boundary mark the change of the seismic regime at north of this latitude (20.75°N), however some shallow events were located at the region of Nayarit.

  7. Isostatic compression of buffer blocks. Middle scale

    Energy Technology Data Exchange (ETDEWEB)

    Ritola, J.; Pyy, E. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2012-01-15

    Manufacturing of buffer components using isostatic compression method has been studied in small scale in 2008 (Laaksonen 2010). These tests included manufacturing of buffer blocks using different bentonite materials and different compression pressures. Isostatic mould technology was also tested, along with different methods to fill the mould, such as vibration and partial vacuum, as well as a stepwise compression of the blocks. The development of manufacturing techniques has continued with small-scale (30 %) blocks (diameter 600 mm) in 2009. This was done in a separate project: Isostatic compression, manufacturing and testing of small scale (D = 600 mm) buffer blocks. The research on the isostatic compression method continued in 2010 in a project aimed to test and examine the isostatic manufacturing process of buffer blocks at 70 % scale (block diameter 1200 to 1300 mm), and the aim was to continue in 2011 with full-scale blocks (diameter 1700 mm). A total of nine bentonite blocks were manufactured at 70 % scale, of which four were ring-shaped and the rest were cylindrical. It is currently not possible to manufacture full-scale blocks, because there is no sufficiently large isostatic press available. However, such a compression unit is expected to be possible to use in the near future. The test results of bentonite blocks, produced with an isostatic pressing method at different presses and at different sizes, suggest that the technical characteristics, for example bulk density and strength values, are somewhat independent of the size of the block, and that the blocks have fairly homogenous characteristics. Water content and compression pressure are the two most important properties determining the characteristics of the compressed blocks. By adjusting these two properties it is fairly easy to produce blocks at a desired density. The commonly used compression pressure in the manufacturing of bentonite blocks is 100 MPa, which compresses bentonite to approximately

  8. Vector electrocardiographic alterations after percutaneous septal ablation in obstructive hypertrophic cardiomyopathy: possible anatomic causes

    Directory of Open Access Journals (Sweden)

    Pérez Riera Andrés Ricardo

    2002-01-01

    Full Text Available OBJECTIVE: Analyze the dromotropic disturbances (vector-electrocardiographic, and the possible anatomic causes, provoked by selective alcohol injection in the septal branch, for percutaneous treatment, of obstructive hypertrophic cardiomyopathy. METHODS: Ten patients with a mean age of 52.7 years underwent percutaneous septal ablation (PTSA from october 1998; all in functional class III/IV. Twelve-lead electrocardiogram was performed prior to and during PTSA, and later electrocardiogram and vectorcardiogram according to Frank's method. The patients were followed up for 32 months. RESULTS: On electrocardiogram (ECG prior to PTSA all patients had sinus rhythm and left atrial enlargement, 8 left ventricular hypertrophy of systolic pattern. On ECG immediately after PTSA, 8 had complete right bundle-branch block; 1 transient total atrioventricular block; 1 alternating transient bundle-branch block either right or hemiblock. On late ECG 8 had complete right bundle-branch block confirmed by vectorcardiogram, type 1 or Grishman. CONCLUSION: Septal fibrosis following alcohol injection caused a predominance of complete right bundle-branch block, different from surgery of myotomy/myectomy.

  9. System Synthesis for Networks of Programmable Blocks

    CERN Document Server

    Mannion, Ryan; Cotterell, Susan; Vahid, Frank

    2011-01-01

    The advent of sensor networks presents untapped opportunities for synthesis. We examine the problem of synthesis of behavioral specifications into networks of programmable sensor blocks. The particular behavioral specification we consider is an intuitive user-created network diagram of sensor blocks, each block having a pre-defined combinational or sequential behavior. We synthesize this specification to a new network that utilizes a minimum number of programmable blocks in place of the pre-defined blocks, thus reducing network size and hence network cost and power. We focus on the main task of this synthesis problem, namely partitioning pre-defined blocks onto a minimum number of programmable blocks, introducing the efficient but effective PareDown decomposition algorithm for the task. We describe the synthesis and simulation tools we developed. We provide results showing excellent network size reductions through such synthesis, and significant speedups of our algorithm over exhaustive search while obtaining...

  10. General Floorplans with L/T-Shaped Blocks Using Corner Block List

    Institute of Scientific and Technical Information of China (English)

    Yu-Chun Ma; Xian-Long Hong; She-Qin Dong; C.K.Cheng; Jun Gu

    2006-01-01

    With the recent advent of deep submicron technology and new packing schemes, the components in the integrated circuit are often not rectangular. On the basis of the representation of Corner Block List (CBL), we propose a new method of handling rectilinear blocks. In this paper, the handling of the rectilinear blocks is simplified by transforming the L/T-shaped block problem into the align-abutment constraint problem. We devise the block rejoining process and block alignment operation for forming the L/T-shaped blocks into their original configurations. The shape flexibility of the soft blocks, and the rotation and reflection of L/T-shaped blocks are exploited to obtain a tight packing. The empty rooms are introduced to the process of block rejoining. The efficiency and effectiveness of the proposed method are demonstrated by the experimental results on a set of some benchmark examples.

  11. Cryptanalysis of Selected Block Ciphers

    DEFF Research Database (Denmark)

    Alkhzaimi, Hoda A.

    thoroughly, no security assessment is given. We present a series of observations on the presented construction that, in some cases, yield attacks, while in other cases may provide basis of further analysis by the cryptographic community. Specifically, The attacks obtained are using classical- as well...... ciphers initiatives, and the Competition for Authenticated Encryption: Security, Applicability, and Robustness (CAESAR). In this thesis, we first present cryptanalytic results on different ciphers. We propose attack named the Invariant Subspace Attack. It is utilized to break the full block cipher...... PRINTcipher for a significant fraction of its keys. This new attack also gives us new insights into other, more well-established attacks. In addition, we also show that for weak keys, strongly biased linear approximations exists for any number of rounds. Furthermore, we provide variety of attacks...

  12. [Ultrasound for peripheral neural block].

    Science.gov (United States)

    Kefalianakis, F

    2005-03-01

    Ultrasound is well established in medicine. Unfortunately, ultrasound is still rarely used in the area of anesthesia. The purpose of the article is to illustrate the possibilities and limitations of ultrasound in regional anesthesia. The basic principles of ultrasound are the piezoelectric effect and the behaviour of acoustic waveforms in human tissue. Ultrasound imaging in medicine uses high frequency pulses of sound waves (2.5-10 MHz). The following images are built up from the reflected sounds. The ultrasound devices used in regional anesthesia (commonly by 10 MHz) deliver a two-dimensional view. The main step for a successful regional anaesthesia is to identify the exact position of the nerve. In addition, specific surface landmarks and the use of peripheral nerve stimulator help to detect the correct position of the needle. Nerves are demonstrated as an composition of hyperechogenic (white) and hypoechogenic (black) areas. The surrounding hyperechogenic parts are epi- and perineurium, the dark hypoechogenic part is the neural tissue. The composition of peripheral nerves are always similar, but the quantities of each part, of surrounding perineurium and nerval structures, differ. Further the imaging of nerves is significantly influenced by the angle of beam to the nerve and the surrounding anatomic structures. Only experience and correct interpretation make the ultrasound a valid method in clinical practice. Correct interpretation has to be learned by standardized education. Three examples of peripheral nerve blocks are described. The detection of nerves and the visualization of the correct spread of local anesthetics to the nerves are the main principles of effective ultrasound-guided regional anesthesia, whereas closest proximity of the needle to the target nerve is not necessary. The described examples of ultrasound guidance for nerval block illustrates the specific procedures with reduced probability of nerval irritation, high success and low rate of

  13. The association between biventricular pacing and cardiac resynchronization therapy-defibrillator efficacy when compared with implantable cardioverter defibrillator on outcomes and reverse remodelling

    DEFF Research Database (Denmark)

    Ruwald, Anne-Christine; Kutyifa, Valentina; Ruwald, Martin H;

    2015-01-01

    : Using Kaplan-Meier plots, we estimated the threshold of BIV pacing percentage needed for CRT-D to be superior to ICD on the end-point of heart failure (HF) or death in 1219 left bundle branch block (LBBB) patients in the MADIT-CRT trial. Patients were censored at the time of crossover. In multivariable...

  14. Disease: H01263 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available H01263 Progressive cardiac conduction defect (PCCD); Progressive familial heart blo...ck (PFHB); Lenegre-Lev disease Progressive cardiac conduction defect (PCCD) is a cardiac bundle branch disor... Pattier S, Babuty D, Mabo P, Mansourati J, Victor J, Nguyen JM, Schott JJ, Boisseau P, Escande D, Le Marec H Progress

  15. Efficient Distribution of Triggered Synchronous Block Diagrams

    Science.gov (United States)

    2011-10-21

    called a trigger. At a given synchronous step, if the trigger is true , the block fires normally; otherwise, the block stutters , that is, keeps its...outputs have the same value as in the previous step, but they are still transmitted to downstream blocks. In this paper we present an implementation...optimizations that apply to general Triggered SBDs, we also present further optimizations for the case of Timed SBDs. 1.1 Motivating Examples Fig. 1

  16. Advanced heart block in acute rheumatic fever.

    Science.gov (United States)

    Hubail, Zakariya; Ebrahim, Ishaq M

    2016-04-01

    First degree heart block is considered a minor criterion for the diagnosis of this condition. The cases presented here demonstrate that higher degrees of heart block do occur in rheumatic fever. Children presenting with acquired heart block should be worked-up for rheumatic fever. Likewise, it is imperative to serially follow the electrocardiogram in patients already diagnosed with acute rheumatic fever, as the conduction abnormalities can change during the course of the disease.

  17. Advanced heart block in acute rheumatic fever

    OpenAIRE

    2015-01-01

    First degree heart block is considered a minor criterion for the diagnosis of this condition. The cases presented here demonstrate that higher degrees of heart block do occur in rheumatic fever. Children presenting with acquired heart block should be worked-up for rheumatic fever. Likewise, it is imperative to serially follow the electrocardiogram in patients already diagnosed with acute rheumatic fever, as the conduction abnormalities can change during the course of the disease.

  18. Using Interference to Block RFID Tags

    DEFF Research Database (Denmark)

    Krigslund, Rasmus; Popovski, Petar; Pedersen, Gert Frølund

    We propose a novel method to block RFID tags from responding, using intentional interference. We focus on the experimental evaluation, where we impose interference on the download and uplink, respectively. The results are positive, where modulated CCI shows most effective to block a tag.......We propose a novel method to block RFID tags from responding, using intentional interference. We focus on the experimental evaluation, where we impose interference on the download and uplink, respectively. The results are positive, where modulated CCI shows most effective to block a tag....

  19. Modelling of multi-block data

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar; Svinning, K.

    2006-01-01

    Here is presented a unified approach to modelling multi-block regression data. The starting point is a partition of the data X into L data blocks, X = (X-1, X-2,...X-L), and the data Y into M data-blocks, Y = (Y-1, Y-2,...,Y-M). The methods of linear regression, X -> Y, are extended to the case...... these methods can be extended to a network of data blocks. Examples of the optimisation procedures in a network are shown. The examples chosen are the ones that are useful to work within industrial production environments. The methods are illustrated by simulated data and data from cement production....

  20. A New Relationship between Block Designs

    Directory of Open Access Journals (Sweden)

    Alexander Shramchenko

    2016-01-01

    Full Text Available We propose a procedure of constructing new block designs starting from a given one by looking at the intersections of its blocks with various sets and grouping those sets according to the structure of the intersections. We introduce a symmetric relationship of friendship between block designs built on a set V and consider families of block designs where all designs are friends of each other, the so-called friendly families. We show that a friendly family admits a partial ordering. Furthermore, we exhibit a map from the power set of V, partially ordered by inclusion, to a friendly family of a particular type which preserves the partial order.

  1. Recent developments in paediatric neuraxial blocks

    Directory of Open Access Journals (Sweden)

    Vrushali Chandrashekhar Ponde

    2012-01-01

    Full Text Available Paediatric anaesthesia and paediatric regional anaesthesia are intertwined. Almost all surgeries unless contradicted could be and should be supplemented with a regional block. The main objective of this review is to elaborate on the recent advances of the central neuraxial blocks, such as application of ultrasound guidance and electrical stimulation in the pursuit of safety and an objective end point. This review also takes account of the traditional technique and understand the benefits as well the risk of each as compared with the recent technique. The recent trends in choosing the most appropriate peripheral block for a given surgery thereby sparing the central neuroaxis is considered. A penile block for circumcision or a sciatic block for unilateral foot surgery, rather than caudal epidural would have a better risk benefit equation. Readers will find a special mention on the recent thoughts on continuous epidural analgesia in paediatrics, especially its rise and fall, yet its unique importance. Lastly, the issue of block placements under sedation or general anaesthesia with its implication in this special population is dealt with. We conducted searches in MEDLINE (PubMed and assessed the relevance of the abstracts of citations identified from literature searches. The search was carried out in English, for last 10 years, with the following key words: Recent advances in paediatric regional anaesthesia; ultrasound guidance for central neuraxial blocks in children; role of electrical stimulation in neuraxial blocks in children; complications in neuraxial block. Full-text articles of potentially relevant abstracts were retrieved for further review.

  2. PACS photometer calibration block analysis

    CERN Document Server

    Moór, A; Kiss, Cs; Balog, Z; Billot, N; Marton, G

    2013-01-01

    The absolute stability of the PACS bolometer response over the entire mission lifetime without applying any corrections is about 0.5% (standard deviation) or about 8% peak-to-peak. This fantastic stability allows us to calibrate all scientific measurements by a fixed and time-independent response file, without using any information from the PACS internal calibration sources. However, the analysis of calibration block observations revealed clear correlations of the internal source signals with the evaporator temperature and a signal drift during the first half hour after the cooler recycling. These effects are small, but can be seen in repeated measurements of standard stars. From our analysis we established corrections for both effects which push the stability of the PACS bolometer response to about 0.2% (stdev) or 2% in the blue, 3% in the green and 5% in the red channel (peak-to-peak). After both corrections we still see a correlation of the signals with PACS FPU temperatures, possibly caused by parasitic h...

  3. Comparative study between ultrasound guided tap block and paravertebral block in upper abdominal surgeries. Randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Ruqaya M. Elsayed

    2017-01-01

    Conclusion: We concluded that ultrasound guided transversus abdominis plane block and thoracic paravertebral block were safe and effective anesthetic technique for upper abdominal surgery with longer and potent postoperative analgesia in thoracic paravertebral block than transversus abdominis block.

  4. Erosion patterns on dissolving blocks

    Science.gov (United States)

    Courrech du Pont, Sylvain; Cohen, Caroline; Derr, Julien; Berhanu, Michael

    2016-04-01

    Patterns in nature are shaped under water flows and wind action, and the understanding of their morphodynamics goes through the identification of the physical mechanisms at play. When a dissoluble body is exposed to a water flow, typical patterns with scallop-like shapes may appear [1,2]. These shapes are observed on the walls of underground rivers or icebergs. We experimentally study the erosion of dissolving bodies made of salt, caramel or ice into water solutions without external flow. The dissolving mixture, which is created at the solid/liquid interface, undergoes a buoyancy-driven instability comparable to a Rayleigh-Bénard instability so that the dissolving front destabilizes into filaments. This mechanism yields to spatial variations of solute concentration and to differential dissolution of the dissolving block. We first observe longitudinal stripes with a well defined wavelength, which evolve towards chevrons and scallops that interact and move again the dissolving current. Thanks to a careful analysis of the competing physical mechanisms, we propose scaling laws, which account for the characteristic lengths and times of the early regime in experiments. The long-term evolution of patterns is understood qualitatively. A close related mechanism has been proposed to explain structures observed on the basal boundary of ice cover on brakish lakes [3] and we suggest that our experiments are analogous and explain the scallop-like patterns on iceberg walls. [1] P. Meakin and B. Jamtveit, Geological pattern formation by growth and dissolution in aqueous systems, Proc. R. Soc. A 466, 659-694 (2010). [2] P.N. Blumberg and R.L. Curl, Experimental and theoretical studies of dissolution roughness, J. Fluid Mech. 65, 735-751 (1974). [3] L. Solari and G. Parker, Morphodynamic modelling of the basal boundary of ice cover on brakish lakes, J.G.R. 118, 1432-1442 (2013).

  5. New routes to the synthesis of amylose-block-polystyrene rod-coil block copolymers

    NARCIS (Netherlands)

    Loos, Katja; Müller, Axel H.E.

    2002-01-01

    Hybrid block copolymers amylose-block-polystyrene were synthesized by covalent attachment of maltoheptaose derivatives to end-functionalized polystyrene and subsequent enzymatic grafting from polymerization. The maltoheptaose derivatives were attached by reductive amination or hydrosilation to amino

  6. Block-based image hashing with restricted blocking strategy for rotational robustness

    Science.gov (United States)

    Xiang, Shijun; Yang, Jianquan

    2012-12-01

    Image hashing is a potential solution for image content authentication (a desired image hashing algorithm should be robust to common image processing operations and various geometric distortions). In the literature, researchers pay more attention to block-based image hashing algorithms due to their robustness to common image processing operations (such as lossy compression, low-pass filtering, and additive noise). However, the block-based hashing strategies are sensitive to rotation processing operations. This indicates that the robustness of the block-based hashing methods against rotation operations is an important issue. Towards this direction, in this article we propose a restricted blocking strategy by investigating effect of two rotation operations on an image and its blocks in both theoretical and experimental ways. Furthermore, we apply the proposed blocking strategy for the recently reported non-negative matrix factorization (NMF) hashing. Experimental results have demonstrated the validity of the block-based hashing algorithms with restricted blocking strategy for rotation operations.

  7. Block Gas Sol Unit in Haderslev

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    2000-01-01

    Investigation of a SDHW system based on a Block Gas Sol Unit from Baxi A/S installed by a consumer i Haderslev, Denmark.......Investigation of a SDHW system based on a Block Gas Sol Unit from Baxi A/S installed by a consumer i Haderslev, Denmark....

  8. Light extraction block with curved surface

    Science.gov (United States)

    Levermore, Peter; Krall, Emory; Silvernail, Jeffrey; Rajan, Kamala; Brown, Julia J.

    2016-03-22

    Light extraction blocks, and OLED lighting panels using light extraction blocks, are described, in which the light extraction blocks include various curved shapes that provide improved light extraction properties compared to parallel emissive surface, and a thinner form factor and better light extraction than a hemisphere. Lighting systems described herein may include a light source with an OLED panel. A light extraction block with a three-dimensional light emitting surface may be optically coupled to the light source. The three-dimensional light emitting surface of the block may includes a substantially curved surface, with further characteristics related to the curvature of the surface at given points. A first radius of curvature corresponding to a maximum principal curvature k.sub.1 at a point p on the substantially curved surface may be greater than a maximum height of the light extraction block. A maximum height of the light extraction block may be less than 50% of a maximum width of the light extraction block. Surfaces with cross sections made up of line segments and inflection points may also be fit to approximated curves for calculating the radius of curvature.

  9. Benchmarking Block Ciphers for Wireless Sensor Networks

    NARCIS (Netherlands)

    Law, Y.W.; Doumen, J.M.; Hartel, P.H.

    2004-01-01

    Choosing the most storage- and energy-efficient block cipher specifically for wireless sensor networks (WSNs) is not as straightforward as it seems. To our knowledge so far, there is no systematic evaluation framework for the purpose. We have identified the candidates of block ciphers suitable for W

  10. The Block Grant Record: Lessons from Experience.

    Science.gov (United States)

    Hastings, Anne H.

    1982-01-01

    Evaluates the performance of federal block grants in health, law enforcement, peoplepower training, community development, and Social Security programs, to help forecast the effects of such grants in education. Finds that block grants did not improve local control, accountability, citizen participation, efficiency, targeting of funds, or program…

  11. CONJUGATED BLOCK-COPOLYMERS FOR ELECTROLUMINESCENT DIODES

    NARCIS (Netherlands)

    Hilberer, A; Gill, R.E; Herrema, J.K; Malliaras, G.G; Wildeman, J.; Hadziioannou, G

    1995-01-01

    In this article we review results obtained in our laboratory on the design and study of new light-emitting polymers. We are interested in the synthesis and characterisation of block copolymers with regularly alternating conjugated and non conjugated sequences. The blocks giving rise to luminescence

  12. PEO-related block copolymer surfactants

    DEFF Research Database (Denmark)

    Mortensen, K.

    2001-01-01

    Non-ionic block copolymer systems based on hydrophilic poly(ethylene oxide) and more hydrophobic co-polymer blocks are used intensively in a variety of industrial and personal applications. A brief description on the applications is presented. The physical properties of more simple model systems ...

  13. Earthquake Resistant Submarine Drydock Block System Design

    Science.gov (United States)

    1988-05-01

    acceleration time history. It Is observed that the block on block surfaces for this system had been painted. According to Rabinowicz (1987) [13J, a...Maryland, 1982, p. 272. 166 13. Rabinowicz , Ernest, Lecture, "Tribology", M.I.T., Course 2.800, Fall 1987. 14. Telephone conversation between Tingley

  14. Micellization and Characterization of Block Copolymer Detergents

    DEFF Research Database (Denmark)

    Hvidt, Søren

    Triblock copolymers of the type EPE, where E and P denote ethylene oxide and propylene oxide blocks, respectively, are used widely in industry as emulsifiers, anti-foaming agents, and in delayed drug release. EPE copolymers form micelles with a core of P blocks and different micellar shapes depen...

  15. Haplotype block structure is conserved across mammals

    NARCIS (Netherlands)

    Guryev, Victor; Smits, Bart M G; van de Belt, Jose; Verheul, Mark; Hubner, Norbert; Cuppen, Edwin

    2006-01-01

    Genetic variation in genomes is organized in haplotype blocks, and species-specific block structure is defined by differential contribution of population history effects in combination with mutation and recombination events. Haplotype maps characterize the common patterns of linkage disequilibrium i

  16. C++ application development with Code::Blocks

    CERN Document Server

    Modak, Biplab Kumar

    2013-01-01

    This is a comprehensive tutorial with step-by-step instructions on how to develop applications with Code::Blocks.This book is for C++ developers who wish to use Code::Blocks to create applications with a consistent look and feel across multiple platforms. This book assumes that you are familiar with the basics of the C++ programming language.

  17. Ultrasonographic evaluation of neck hematoma and block salvage after failed neurostimulation-guided interscalene block.

    Science.gov (United States)

    Howell, Stephen M; Unger, M W Todd; Colson, James D; Serafini, Mario

    2010-11-01

    Ultrasound-guided regional anesthetic techniques have shown some advantages over conventional paresthesia and neurostimulation techniques. We report the case of a neurostimulation-guided continuous interscalene block that would have ended in complication were it not for experience with ultrasound-guided regional anesthesia. Familiarity with ultrasound-guided block techniques permitted assessment of a neck hematoma during interscalene block and ultimately allowed successful peripheral nerve block.

  18. Blending of styrene-block-butadiene-block-styrene copolymer with sulfonated vinyl aromatic polymers

    OpenAIRE

    Ruggeri, Giacomo; Passaglia, Elisa; Giorgi, Ivan; Picchioni, Francesco; Aglietto, Mauro

    2001-01-01

    Different polymers containing sulfonic groups attached to the phenyl rings were prepared by sulfonation of polystyrene (PS) and styrene-block-(ethylene-co-1-butene)-block-styrene (SEBS). The sulfonation degree (SD) was varied between 1 and 20 mol% of the styrene units. Polyphase materials containing sulfonated units were prepared by blending styrene-block-butadiene-block-styrene (SBS), with both sulfonated PS and sulfonated SEBS in a Brabender mixer. Such a procedure was performed as an alter...

  19. A Nonlinear Multi-Scale Interaction Model for Atmospheric Blocking: The Eddy-Blocking Matching Mechanism

    Science.gov (United States)

    Luo, Dehai; Cha, Jing; Zhong, Linhao; Dai, Aiguo

    2014-05-01

    In this paper, a nonlinear multi-scale interaction (NMI) model is used to propose an eddy-blocking matching (EBM) mechanism to account for how synoptic eddies reinforce or suppress a blocking flow. It is shown that the spatial structure of the eddy vorticity forcing (EVF) arising from upstream synoptic eddies determines whether an incipient block can grow into a meandering blocking flow through its interaction with the transient synoptic eddies from the west. Under certain conditions, the EVF exhibits a low-frequency oscillation on timescales of 2-3 weeks. During the EVF phase with a negative-over- positive dipole structure, a blocking event can be resonantly excited through the transport of eddy energy into the incipient block by the EVF. As the EVF changes into an opposite phase, the blocking decays. The NMI model produces life cycles of blocking events that resemble observations. Moreover, it is shown that the eddy north-south straining is a response of the eddies to a dipole- or Ω-type block. In our model, as in observations, two synoptic anticyclones (cyclones) can attract and merge with one another as the blocking intensifies, but only when the feedback of the blocking on the eddies is included. Thus, we attribute the eddy straining and associated vortex interaction to the feedback of the intensified blocking on synoptic eddies. The results illustrate the concomitant nature of the eddy deformation, whose role as a PV source for the blocking flow becomes important only during the mature stage of a block. Our EBM mechanism suggests that an incipient block flow is amplified (or suppressed) under certain conditions by the EVF coming from the upstream of the blocking region.

  20. The undesirable effects of neuromuscular blocking drugs

    DEFF Research Database (Denmark)

    Claudius, C; Garvey, L H; Viby-Mogensen, J

    2009-01-01

    Neuromuscular blocking drugs are designed to bind to the nicotinic receptor at the neuromuscular junction. However, they also interact with other acetylcholine receptors in the body. Binding to these receptors causes adverse effects that vary with the specificity for the cholinergic receptor...... in question. Moreover, all neuromuscular blocking drugs may cause hypersensitivity reactions. Often the symptoms are mild and self-limiting but massive histamine release can cause systematic reactions with circulatory and respiratory symptoms and signs. At the end of anaesthesia, no residual effect...... of a neuromuscular blocking drug should be present. However, the huge variability in response to neuromuscular blocking drugs makes it impossible to predict which patient will suffer postoperative residual curarization. This article discusses the undesirable effects of the currently available neuromuscular blocking...

  1. Fermion RG blocking transformations and IR structure

    CERN Document Server

    Cheng, X

    2011-01-01

    We explore fermion RG block-spinning transformations on the lattice with the aim of studying the IR structure of gauge theories and, in particular, the existence of IR fixed points for varying fermion content. In the case of light fermions the main concern and difficulty is ensuring locality of any adopted blocking scheme. We discuss the problem of constructing a local blocked fermion action in the background of arbitrary gauge fields. We then discuss the carrying out of accompanying gauge field blocking. In the presence of the blocked fermions implementation of MCRG is not straightforward. By adopting judicious approximations we arrive at an easily implementable approximate RG recursion scheme that allows quick, inexpensive estimates of the location of conformal windows for various groups and fermion representations. We apply this scheme to locate the conformal windows in the case of SU(2) and SU(3) gauge groups. Some of the reasons for the apparent efficacy of this and similar decimation schemes are discuss...

  2. STUDY ON POLYSULFONE-POLYESTER BLOCK COPOLYMERS

    Institute of Scientific and Technical Information of China (English)

    DING Youjun; QI Daquan

    1988-01-01

    Synthesis and characterization of a series of Polysulfone (PSF)-Polyester (PEs) block copolymers were studied.The degree of randomness (B) of these block copolymers was calculated from the intensities of their proton signals in 1H NMR spectra and lies in the region of 0 < B < 1. It was shown that the degree of randomness (B) and the average sequence length (L) in block copolymers were relatively dependent on the reaction conditions, various feed ratios and structure of diols.The phenomenon was observed, when the PSF-PEs block copolymers dissolved in different solvents they had different viscosities and molecular conformations.The PSF-PEs block copolymers had better solvent resistance than homo-polysulfone.

  3. A note on "Block H-matrices and spectrum of block matrices"

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-zhou; HUANG Ze-jun

    2008-01-01

    In this paper, we make further discussions and improvements on the results presented in the previously published work "Block H-matrices and spectrum of block matrices". Furthermore, a new bound for eigenvalues of block matrices is given with examples to show advantages of the new result.

  4. DYNAMIC BEHAVIOR OF TYRE TREAD BLOCK

    Directory of Open Access Journals (Sweden)

    K. Sridharan

    2012-01-01

    Full Text Available The Tyre tread pattern is the arrangement of blocks, grooves and voids, sipes and channels designed into the tread to enhance its grip on the road. Tread is the uppermost part of any tyre which contact into the road and it has its own performance towards mileage, traction, low noise and heat built up properties. It would be meaningful to conduct an extended analysis on the tyre tread blocks for its performance in static and dynamic condition to predict its behavior and wear of tread block in on-road condition. The Finite Element software Abaqus is used for the present analysis of the tread block and its behavior was studied on two different contact surfaces. The tread block is modeled in six different shapes and analyzed for is performance. The deformation stress strain characteristic of different blocks is studied which will be useful in deciding the contact behavior, friction and road grip. The regular shape/geometry has common behavior and the mixed type geometry shows a distinguished variation in the analysis. The dynamic stiffness and deformed shape was analyzed in this study and it has its own effect in tyre design. The tread block dynamics study by geometric shape would be vital in tread pattern optimization to enhance the traction, better hydroplaning and rolling resistance under all operating conditions.

  5. Development of Alkali Activated Geopolymer Masonry Blocks

    Science.gov (United States)

    Venugopal, K.; Radhakrishna; Sasalatti, Vinod

    2016-09-01

    Cement masonry units are not considered as sustainable since their production involves consumption of fuel, cement and natural resources and therefore it is essential to find alternatives. This paper reports on making of geopolymer solid & hollow blocks and masonry prisms using non conventional materials like fly ash, ground granulated blast furnace slag (GGBFS) and manufactured sand and curing at ambient temperature. They were tested for water absorption, initial rate of water absorption, dry density, dimensionality, compressive, flexural and bond-strength which were tested for bond strength with and without lateral confinement, modulus of elasticity, alternative drying & wetting and masonry efficiency. The properties of geopolymer blocks were found superior to traditional masonry blocks and the masonry efficiency was found to increase with decrease in thickness of cement mortar joints. There was marginal difference in strength between rendered and unrendered geopolymer masonry blocks. The percentage weight gain after 7 cycles was less than 6% and the percentage reduction in strength of geopolymer solid blocks and hollow blocks were 26% and 28% respectively. Since the properties of geopolymer blocks are comparatively better than the traditional masonry they can be strongly recommended for structural masonry.

  6. Circular block matching based video stabilization

    Science.gov (United States)

    Xu, Lidong; Fu, Fangwen; Lin, Xinggang

    2005-07-01

    Video sequences captured by handheld digital camera need to be stabilized to eliminate the tiresome effects caused by camera"s undesirable shake or jiggle. The key issue of video stabilization is to estimate the global motion parameters between two successive frames. In this paper, a novel circular block matching algorithm is proposed to estimate the global motion parameters. This algorithm can deal with not only translational motion but even large rotational motion. For an appointed circular block in current frame, a four-dimensional rotation invariant feature vector is firstly extracted from it and used to judge if it is an effective block. Then the rotation invariant features based circular block matching process is performed to find the best matching blocks in reference frame for those effective blocks. With the matching results of any two effective blocks, a two-dimensional motion model is constructed to produce one group of frame motion parameters. A statistical method is proposed to calculate the estimated global motion parameters with all groups of global motion parameters. Finally, using the estimated motion parameters as the initial values, an iteration algorithm is introduced to obtain the refined global motion parameters. The experimental results show that the proposed algorithm is excellent in stabilizing frames with even burst global translational and rotational motions.

  7. Gaussian curvature analysis allows for automatic block placement in multi-block hexahedral meshing.

    Science.gov (United States)

    Ramme, Austin J; Shivanna, Kiran H; Magnotta, Vincent A; Grosland, Nicole M

    2011-10-01

    Musculoskeletal finite element analysis (FEA) has been essential to research in orthopaedic biomechanics. The generation of a volumetric mesh is often the most challenging step in a FEA. Hexahedral meshing tools that are based on a multi-block approach rely on the manual placement of building blocks for their mesh generation scheme. We hypothesise that Gaussian curvature analysis could be used to automatically develop a building block structure for multi-block hexahedral mesh generation. The Automated Building Block Algorithm incorporates principles from differential geometry, combinatorics, statistical analysis and computer science to automatically generate a building block structure to represent a given surface without prior information. We have applied this algorithm to 29 bones of varying geometries and successfully generated a usable mesh in all cases. This work represents a significant advancement in automating the definition of building blocks.

  8. Measurement of soil moisture using gypsum blocks

    DEFF Research Database (Denmark)

    Friis Dela, B.

    the building. Consequently, measuring the moisture of the surrounding soil is of great importance for detecting the source of moisture in a building. Up till now, information has been needed to carry out individual calibrations for the different types of gypsum blocks available on the market and to account......For the past 50 years, gypsum blocks have been used to determine soil moisture content. This report describes a method for calibrating gypsum blocks for soil moisture measurements. Moisture conditions inside a building are strongly influenced by the moisture conditions in the soil surrounding...

  9. Theory of circuit block switch-off

    Directory of Open Access Journals (Sweden)

    S. Henzler

    2004-01-01

    Full Text Available Switching-off unused circuit blocks is a promising approach to supress static leakage currents in ultra deep sub-micron CMOS digital systems. Basic performance parameters of Circuit Block Switch-Off (CBSO schemes are defined and their dependence on basic circuit parameters is estimated. Therefore the design trade-off between strong leakage suppression in idle mode and adequate dynamic performance in active mode can be supported by simple analytic investigations. Additionally, a guideline for the estimation of the minimum time for which a block deactivation is useful is derived.

  10. Lidocaine block of cardiac sodium channels

    OpenAIRE

    Bean, BP; Cohen, CJ; Tsien, RW

    1983-01-01

    Lidocaine block of cardiac sodium channels was studied in voltage-clamped rabbit purkinje fibers at drug concentrations ranging from 1 mM down to effective antiarrhythmic doses (5-20 μM). Dose-response curves indicated that lidocaine blocks the channel by binding one-to-one, with a voltage-dependent K(d). The half-blocking concentration varied from more than 300 μM, at a negative holding potential where inactivation was completely removed, to approximately 10 μM, at a depolarized holding pote...

  11. Comparative Analysis of Sandcrete Hollow Blocks and Laterite Interlocking Blocks as Walling Elements

    Directory of Open Access Journals (Sweden)

    Akeem Ayinde Raheem

    2012-04-01

    Full Text Available This study considered the production and testing of sandcrete hollow blocks and laterite interlocking blocks with a view to comparing their physical characteristics and production cost. Some units of sandcrete hollow blocks and laterite interlocking blocks were made using machine vibrated sandcrete block mould and hydraulic interlocking block making machine respectively. The blocks were tested to determine their density and compressive strength. The results obtained from the tests were compared with the specifications of Nigerian Building and Road Research Institute (2006, Nigerian Building Code (2006, and Nigerian Industrial Standards (2000. The results indicated that the compressive strength of 225mm and 150mm sandcrete hollow blocks varies from 1.59 N/mm2 to 4.25 N/mm2 and 1.48N/mm2 to 3.35N/mm2 respectively, as the curing age increases from 7 to 28 days. For laterite interlocking blocks, the strength varies from 1.70N/mm2 at 7 days to 5.03N/mm2 at 28 days. All the blocks produced satisfied the minimum requirements in terms of compressive strength, by all available codes. The cost per square metre of 225mm and 150mm sandcrete hollow blocks are ₦2,808:00 and ₦2,340:00 respectively, while that of laterite interlocking blocks is ₦2,121:20.It was concluded that laterite interlocking blocks have better strength and are cheaper than sandcrete hollow blocks.

  12. Exploring Energy Efficiency of Lightweight Block Ciphers

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Bogdanov, Andrey; Regazzoni, Francesco

    2016-01-01

    lightweight block ciphers, and thereby try to predict the optimal value of r at which an r-round unrolled architecture for a cipher is likely to be most energy efficient. We also try to relate our results to some physical design parameters like the signal delay across a round and algorithmic parameters like......In the last few years, the field of lightweight cryptography has seen an influx in the number of block ciphers and hash functions being proposed. One of the metrics that define a good lightweight design is the energy consumed per unit operation of the algorithm. For block ciphers, this operation...... is the encryption of one plaintext. By studying the energy consumption model of a CMOS gate, we arrive at the conclusion that the energy consumed per cycle during the encryption operation of an r-round unrolled architecture of any block cipher is a quadratic function in r. We then apply our model to 9 well known...

  13. Formation of Anisotropic Block Copolymer Gels

    Science.gov (United States)

    Liaw, Chya Yan; Shull, Kenneth; Henderson, Kevin; Joester, Derk

    2011-03-01

    Anisotropic, fibrillar gels are important in a variety of processes. Biomineralization is one example, where the mineralization process often occurs within a matrix of collagen or chitin fibers that trap the mineral precursors and direct the mineralization process. We wish to replicate this type of behavior within block copolymer gels. Particularly, we are interested in employing gels composed of cylindrical micelles, which are anisotropic and closely mimic biological fibers. Micelle geometry is controlled in our system by manipulating the ratio of molecular weights of the two blocks and by controlling the detailed thermal processing history of the copolymer solutions. Small-Angle X-ray Scattering and Dynamic Light Scattering are used to determine the temperature dependence of the gel formation process. Initial experiments are based on a thermally-reversible alcohol-soluble system, that can be subsequently converted to a water soluble system by hydrolysis of a poly(t-butyl methacrylate) block to a poly (methacrylic acid) block. MRSEC.

  14. EnviroAtlas - Milwaukee, WI - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Milwaukee, WI EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  15. Extrinsic germanium Blocked Impurity Bank (BIB) detectors

    Science.gov (United States)

    Krabach, Timothy N.; Huffman, James E.; Watson, Dan M.

    1989-01-01

    Ge:Ga blocked-impurity-band (BIB) detectors with long wavelength thresholds greater than 190 microns and peak quantum efficiencies of 4 percent, at an operating temperature of 1.8 K, have been fabricated. These proof of concept devices consist of a high purity germanium blocking layer epitaxially grown on a Ga-doped Ge substrate. This demonstration of BIB behavior in germanium enables the development of far infrared detector arrays similar to the current silicon-based devices. Present efforts are focussed on improving the chemical vapor deposition process used to create the blocking layer and on the lithographic processing required to produce monolithic detector arrays in germanium. Approaches to test the impurity levels in both the blocking and active layers are considered.

  16. EnviroAtlas - Fresno, CA - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Fresno, CA EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  17. Functionalization of Block Copolymer Vesicle Surfaces

    Directory of Open Access Journals (Sweden)

    Wolfgang Meier

    2011-01-01

    Full Text Available In dilute aqueous solutions certain amphiphilic block copolymers self-assemble into vesicles that enclose a small pool of water with a membrane. Such polymersomes have promising applications ranging from targeted drug-delivery devices, to biosensors, and nanoreactors. Interactions between block copolymer membranes and their surroundings are important factors that determine their potential biomedical applications. Such interactions are influenced predominantly by the membrane surface. We review methods to functionalize block copolymer vesicle surfaces by chemical means with ligands such as antibodies, adhesion moieties, enzymes, carbohydrates and fluorophores. Furthermore, surface-functionalization can be achieved by self-assembly of polymers that carry ligands at their chain ends or in their hydrophilic blocks. While this review focuses on the strategies to functionalize vesicle surfaces, the applications realized by, and envisioned for, such functional polymersomes are also highlighted.

  18. EnviroAtlas - Portland, OR - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Portland, OR EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  19. EnviroAtlas - Cleveland, OH - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Cleveland, OH EnviroAtlas community. The block groups are from the US Census Bureau and are included/excluded...

  20. EnviroAtlas - Paterson, NJ - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Paterson, NJ EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  1. EnviroAtlas - Memphis, TN - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Memphis, TN EnviroAtlas community. The block groups are from the US Census Bureau and are included/excluded based...

  2. EnviroAtlas - Phoenix, AZ - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Phoenix, AZ EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  3. Algorithms for Finding the Inverses of Factor Block Circulant Matrices

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, algorithms for finding the inverse of a factor block circulant matrix,a factor block retrocirculant matrix and partitioned matrix with factor block circulant blocks over the complex field are presented respectively. In addition, two algorithms for the inverse of a factor block circulant matrix over the quaternion division algebra are proposed.

  4. Adaptive cosine transform image coding with variable block size and constant block distortion

    Science.gov (United States)

    Daut, David G.; Wu, Jia-Chyi

    1996-02-01

    An adaptive discrete cosine transform (DCT) image coding system is implemented with the same average distortion designated for each variable size image block. The variable block size segmentation is performed using a quadtree data structure by dividing the perceptually more important regions of an image into smaller size blocks compared to the size of blocks containing lesser amounts of spatial activity. Due to the nonstationarity of real-world images, each image block is described by a space-varying nonstationary Gauss-Markov random field. The space-varying autoregressive parameters are estimated using an on-line modified least- squares estimator. For each assumed space-varying nonstationary image block, a constant average distortion is assigned and the code rate for each image block is allowed to vary in order to meet the fixed distortion criterion. Simulation results show that reconstructed images coded at low average distortion, based on an assumed space-varying nonstationary image model, using variable size blocks and with variable bit rate per block possess high-quality subjective (visual) and objective (measured) quality at low average bit rates. Performance gains are achieved due to the distortion being distributed more uniformly among the blocks as compared with fixed-rate, stationary image transform coding schemes.

  5. Building-block selectivity of polyketide synthases.

    Science.gov (United States)

    Liou, Grace F; Khosla, Chaitan

    2003-04-01

    For the past decade, polyketide synthases have presented an exciting paradigm for the controlled manipulation of complex natural product structure. These multifunctional enzymes catalyze the biosynthesis of polyketide natural products by stepwise condensation and modification of metabolically derived building blocks. In particular, regioselective modification of polyketide structure is possible by alterations in either intracellular acyl-CoA pools or, more commonly, by manipulation of acyl transferases that act as the primary gatekeepers for building blocks.

  6. Permutations with Ascending and Descending Blocks

    CERN Document Server

    Steinhardt, Jacob

    2009-01-01

    We investigate permutations in terms of their cycle structure and descent set. To do this, we generalize the classical bijection of Gessel and Reutenauer to deal with permutations that have some ascending and some descending blocks. We then provide the first bijective proofs of some known results. We also solve some problems posed in [3] by Eriksen, Freij, and Wastlund, who study derangements that descend in blocks of prescribed lengths.

  7. Dietary cholesterol modulates pathogen blocking by Wolbachia.

    Directory of Open Access Journals (Sweden)

    Eric P Caragata

    Full Text Available The bacterial endosymbiont Wolbachia pipientis protects its hosts from a range of pathogens by limiting their ability to form infections inside the insect. This "pathogen blocking" could be explained by innate immune priming by the symbiont, competition for host-derived resources between pathogens and Wolbachia, or the direct modification of the cell or cellular environment by Wolbachia. Recent comparative work in Drosophila and the mosquito Aedes aegypti has shown that an immune response is not required for pathogen blocking, implying that there must be an additional component to the mechanism. Here we have examined the involvement of cholesterol in pathogen blocking using a system of dietary manipulation in Drosophila melanogaster in combination with challenge by Drosophila C virus (DCV, a common fly pathogen. We observed that flies reared on cholesterol-enriched diets infected with the Wolbachia strains wMelPop and wMelCS exhibited reduced pathogen blocking, with viral-induced mortality occurring 2-5 days earlier than flies reared on Standard diet. This shift toward greater virulence in the presence of cholesterol also corresponded to higher viral copy numbers in the host. Interestingly, an increase in dietary cholesterol did not have an effect on Wolbachia density except in one case, but this did not directly affect the strength of pathogen blocking. Our results indicate that host cholesterol levels are involved with the ability of Wolbachia-infected flies to resist DCV infections, suggesting that cholesterol contributes to the underlying mechanism of pathogen blocking.

  8. Tunable Morphologies from Charged Block Copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Goswami, Monojoy [ORNL; Sumpter, Bobby G [ORNL; Mays, Jimmy [ORNL; Messman, Jamie M [ORNL

    2010-01-01

    The bulk morphologies formed by a new class of charged block copolymers, 75 vol % fluorinated polyisoprene (FPI) 25 vol% sulfonated polystyrene (PSS) with 50% sulfonation, are characterized, and the fundamental underlying forces that promote the self-assembly processes are elucidated. The results show how the bulk morphologies are substantially different from their uncharged diblock counterparts (PS-PI) and also how morphology can be tuned with volume fraction of the charged block and the casting solvent. A physical understanding based on the underlying strong electrostatic interactions between the charged block and counterions is obtained using Monte Carlo (MC) and Molecular Dynamics (MD) simulations. The 75/25 FPI-PSS shows hexagonal morphologies with the minority blocks (PSS) forming the continuous phase due to charge percolation and the FPI blocks arranged in hexagonal cylinders. Some long-range order can be sustained even if lipophobicity is increased (addition of water), albeit with lower dimensional structures. However, thermal annealing provides sufficient energy to disrupt the percolated charges and promotes aggregation of ionic sites which leads to a disordered system. Diverse and atypical morphologies are readily accessible by simply changing the number distribution of the charges on PSS block.

  9. Helical Ordering in Chiral Block Copolymers

    Science.gov (United States)

    Zhao, Wei; Hong, Sung Woo; Chen, Dian; Grason, Gregory; Russell, Thomas

    2012-02-01

    Introducing molecular chirality into the segments of block copolymers can influence the nature of the resultant morphology. Such an effect was found for poly(styrene-b-L-lactide) (PS-b-PLLA) diblock copolymers where hexagonally packed PLLA helical microdomains (H* phase) form in a PS matrix. However, molecular ordering of PLLA within the helical microdomains and the transfer of chirality from the segmental level to the mesoscale is still not well understood. We developed a field theoretic model to describe the interactions between segments of chiral blocks, which have the tendency to form a ``cholesteric'' texture. Based on the model, we calculated the bulk morphologies of chiral AB diblock copolymers using self-consistent field theory (SCFT). Experiments show that the H* phase only forms when microphase separation between PS and PLLA block happens first and crystallization of PLLA block is suppressed or happens within confined microdomain. Hence, crystalline ordering is not necessary for H* phase formation. The SCFT offers the chance to explore the range of thermodynamic stability of helical structures in the phase diagram of chiral block copolymer melts, by tuning parameters not only like the block segregation strength and composition, but also new parameters such as the ratio between preferred helical pitch to the radius of gyration and the Frank elastic constant for inter-segment distortions.

  10. Block copolymer membranes for aqueous solution applications

    KAUST Repository

    Nunes, Suzana Pereira

    2016-03-22

    Block copolymers are known for their intricate morphology. We review the state of the art of block copolymer membranes and discuss perspectives in this field. The main focus is on pore morphology tuning with a short introduction on non-porous membranes. The two main strategies for pore formation in block copolymer membranes are (i) film casting and selective block sacrifice and (ii) self-assembly and non-solvent induced phase separation (SNIPS). Different fundamental aspects involved in the manufacture of block copolymer membranes are considered, including factors affecting the equilibrium morphology in solid films, self-assembly of copolymer in solutions and macrophase separation by solvent-non-solvent exchange. Different mechanisms are proposed for different depths of the SNIPS membrane. Block copolymer membranes can be prepared with much narrower pore size distribution than homopolymer membranes. Open questions and indications of what we consider the next development steps are finally discussed. They include the synthesis and application of new copolymers and specific functionalization, adding characteristics to respond to stimuli and chemical environment, polymerization-induced phase separation, and the manufacture of organic-inorganic hybrids.

  11. Adaptive overlapped sub-blocks contrast enhancement

    Science.gov (United States)

    Chen, Anqiu; Yuan, Fei; Liu, Jing; Liu, Siqi; Li, An; Zheng, Zhenrong

    2016-09-01

    In this paper, an overlapped sub-block gray-level average method for contrast enhancement is presented. The digital image correction of uneven illumination under microscope transmittance is a problem in image processing, also sometimes the image in the dark place need to correct the uneven problem. A new correction method was proposed based on the mask method and sub-blocks gray-level average method because Traditional mask method and background fitting method are restricted due to application scenarios, and the corrected image brightness is low by using background fitting method, so it has some limitations of the application. In this paper, we introduce a new method called AOSCE for image contrast enhancement. The image is divided into many sub-blocks which are overlapped, calculate the average gray-level of the whole image as M and the calculate the average gray-level of each one as mi, next for each block it can get d = mi - m, each block minus d to get a new image, and then get the minimum gray-level of each block into a matrix DD to get the background, and use bilinearity to get the same scale of the image. over fitting the image in matlab in order to get smoother image, then minus the background to get the contrast enhancement image.

  12. Synthesis of segmented (pb(ps-block-pb)(n)) and (pb(san-block- pb)(n)) block-copolymers via polymeric thermal iniferters

    NARCIS (Netherlands)

    Kroeze, E; ten Brinke, G.; Hadziioannou, G

    1995-01-01

    A technique is described for the synthesis of segmented poly(butadiene-block-styrene) block copolymers and segmented poly(butadiene-block-(styrene-co-acrylonitrile)) block copolymers through polybutadiene-based thermal iniferters. Dihydroxy- and dicarboxy-terminated polybutadienes were transformed i

  13. The Early Paleozoic paleogeography of the North China block and the other major blocks of China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    With the summarization of the Early Paleozoic paleomagnetic data recently obtained from the three major blocks of China, the Early Paleozoic (I.e. Cambrian and Ordovician) paleogeographic positions of the North China, South China and Tarim blocks were discussed in detail. The North China, South China and Tarim blocks were inferred to be located adjacent to East Gondwana in low latitudes of the Southern Hemisphere during the Early Cambrian. During the Early-Middle Ordovician, the South China and Tarim blocks were also located in low latitudes of the Southern Hemisphere with some affinities of the Gondwanaland, whereas the North China block may have episodically separated from the Gondwanaland, and might be sited close to the North America and Siberia. The reestablished paleogeographic configurations are in agreement with the studies on the biogeography, paleoclimate and sedimental facies of the North China and South China blocks.

  14. Adductor canal block versus femoral nerve block for analgesia after total knee arthroplasty

    DEFF Research Database (Denmark)

    Jaeger, Pia; Zaric, Dusanka; Fomsgaard, Jonna Storm;

    2013-01-01

    Femoral nerve block (FNB), a commonly used postoperative pain treatment after total knee arthroplasty (TKA), reduces quadriceps muscle strength essential for mobilization. In contrast, adductor canal block (ACB) is predominately a sensory nerve block. We hypothesized that ACB preserves quadriceps...... muscle strength as compared with FNB (primary end point) in patients after TKA. Secondary end points were effects on morphine consumption, pain, adductor muscle strength, morphine-related complications, and mobilization ability....

  15. Synthesis of polyacrylonitrile-block-polydimethylsiloxane-block-polyacrylonitrile triblock copolymers via RAFT polymerization

    Institute of Scientific and Technical Information of China (English)

    Zheng Yue; Deng Xu Wang; Jing Quan Liu; Jie Zhang; Sheng Yu Feng

    2012-01-01

    A new A-B-A type of block copolymers,polyacrylonitrile-block-polydimethylsiloxane-block-polyacrylonitrile (PAN-b-PDMS-b-PAN),which comprises two polymer blocks of different polarities and compatibilities,were synthesized for the first time via reversible addition-fragmentation chain transfer polymerization.Reaction kinetics was investigated.PAN-b-PDMS-b-PAN films were prepared by spin-coating on glass chips.Significant order on the film surface morphologies was observed.(C) 2012 Jie Zhang.Published by Elsevier B.V.on behalf of Chinese Chemical Society.All rights reserved.

  16. [Effectiveness of sympathetic block using various technics].

    Science.gov (United States)

    Weissenberg, W

    1987-07-01

    Blocking of sympathetic conduction aims at permanent or temporary elimination of those pain pathways conducted by the sympathetic nervous system. In order to provide an objective evaluation of sufficient blocking effect, earlier inquiries referred to parameters such as: (1) observation of clinical signs such as Horner's syndrome, Guttman's sign, anhidrosis, extended venous filling; (2) difference in skin temperature of at least 1.5 degrees C between blocked and unblocked side; (3) increase in amplitude of the pulse wave; and (4) depression of the psychogalvanic reflex (PGR) on the blocked side (Fig. 1). In clinical practice, these control parameters are effective because they are time-saving, technically simple, and highly evidential. Further parameters for evaluating sympathetic blockade are examination of hydrosis by means of color indicators such as bromocresol and ninhydrin, oscillometry, and plethysmography. The effectiveness of sympathetic blockade after stellate ganglion and sympathetic trunk blocks has been verified by various authors. In a clinical study, 16 patients were divided into four groups in order to test the effectiveness of sympathetic blockade after spinal anesthesia with 3 ml 0.75% bupivacaine (group I) and 4 ml 0.75% bupivacaine (group II) and after peridural anesthesia with 15 ml 0.75% bupivacaine (group III) and 20 ml 0.75% bupivacaine (group IV) by means of temperature difference, response of pulse wave amplitude and PGR between blocked lower and unblocked upper extremity, and sensory levels of block. The patients were classified as ASA I and II; their ages varied from 20 to 63 years.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. A potential vorticity perspective on atmospheric blocking?

    Science.gov (United States)

    Croci Maspoli, M.; Schwierz, C.

    2003-04-01

    A persistent large-scale anomaly of the west to east flow in the midlatitudes with a weakening and meridional splitting of the jet can be specified as atmospheric blocking. Lifetimes last from several days up to weeks so that blocking can therefore significantly determine monthly circulation index values. The vertical range affected by this phenomenon covers the entire troposphere as mirrored in increased surface pressure as well as an elevated tropopause and is also felt in the lower-stratosphere. Here we seek to shed more light on the physical mechanisms related to blocking by adopting the PV (potential vorticity) perspective with a focus on tropopause-level dynamics. Processes such as Rossby-wave breaking and diabatic heating can modify the conservative behaviour of the PV and are therefore important features for the formation and maintenance of atmospheric blocking. This motivates the definition of a novel blocking index based upon the three-dimensional structure of the phenomenon. A vertically integrated measure (PV within the 500 - 150 hPa layer, VIPV) is calculated, underlining the quasi-barotropic nature of blocked atmospheric state. Benefits of the new index include: representation of the two-dimensional structure of the phenomenon, its lifecycle and geographical distribution. The investigation is conducted over the period 1979 to 2001 using ECMWF reanalysis data. Characteristics of the VIPV field are presented. The new VIPV index is compared to a standard blocking index (e.g. Tibaldi and Molteni (1989)) on a case study basis and also with respect to seasonal variability. Relations to climate modes/indices (NAO, AO) are also discussed.

  18. Decomposition of Data Mining Algorithms into Unified Functional Blocks

    Directory of Open Access Journals (Sweden)

    Ivan Kholod

    2016-01-01

    Full Text Available The present paper describes the method of creating data mining algorithms from unified functional blocks. This method splits algorithms into independently functioning blocks. These blocks must have unified interfaces and implement pure functions. The method allows us to create new data mining algorithms from existing blocks and improves the existing algorithms by optimizing single blocks or the whole structure of the algorithms. This becomes possible due to a number of important properties inherent in pure functions and hence functional blocks.

  19. Ultrasound guided TAP block versus ultrasound guided caudal block for pain relief in children undergoing lower abdominal surgeries

    Directory of Open Access Journals (Sweden)

    Wafaa Mohamed Alsadek

    2015-04-01

    Conclusion: TAP block and caudal block under ultrasound guidance proved to be safe with no recorded complications either intra or postoperatively. Patient and parent satisfaction was markedly observed in case of TAP block.

  20. Mineral resources estimation based on block modeling

    Science.gov (United States)

    Bargawa, Waterman Sulistyana; Amri, Nur Ali

    2016-02-01

    The estimation in this paper uses three kinds of block models of nearest neighbor polygon, inverse distance squared and ordinary kriging. The techniques are weighting scheme which is based on the principle that block content is a linear combination of the grade data or the sample around the block being estimated. The case study in Pongkor area, here is gold-silver resource modeling that allegedly shaped of quartz vein as a hydrothermal process of epithermal type. Resources modeling includes of data entry, statistical and variography analysis of topography and geological model, the block model construction, estimation parameter, presentation model and tabulation of mineral resources. Skewed distribution, here isolated by robust semivariogram. The mineral resources classification generated in this model based on an analysis of the kriging standard deviation and number of samples which are used in the estimation of each block. Research results are used to evaluate the performance of OK and IDS estimator. Based on the visual and statistical analysis, concluded that the model of OK gives the estimation closer to the data used for modeling.

  1. Chain exchange in block copolymer micelles

    Science.gov (United States)

    Lu, Jie; Bates, Frank; Lodge, Timothy

    2014-03-01

    Block copolymer micelles are aggregates formed by self-assembly of amphiphilic copolymers dispersed in a selective solvent, driven by unfavorable interactions between the solvent and the core-forming block. Due to the relatively long chains being subject to additional thermodynamic and dynamic constraints (e.g., entanglements, crystallinity, vitrification), block copolymer micelles exhibit significantly slower equilibration kinetics than small molecule surfactants. As a result, details of the mechanism(s) of equilibration in block copolymer micelles remain unclear. This present works focuses on the chain exchange kinetics of poly(styrene-b-ethylenepropylene) block copolymers in squalane (C30H62) using time-resolved small angle neutron scattering (TR-SANS). A mixture of h-squalane and d-squalane is chosen so that it contrast matches a mixed 50/50 h/d polystyrene micelle core. When the temperature is appropriate and isotopically labeled chains undergo mixing, the mean core contrast with respect to the solvent decreases, and the scattering intensity is therefore reduced. This strategy allows direct probing of chain exchange rate from the time dependent scattering intensity I(q, t).

  2. Natural convection through enclosed disconnected solid blocks

    Energy Technology Data Exchange (ETDEWEB)

    Lao, Fernando Cesar De; Junqueira, Silvio L.M.; Franco, Admilson T. [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil)]. E-mails: fernandodelai@gmail.com; silvio@utfpr.edu.br; admilson@utfpr.edu.br; Lage, Jose L. [Southern Methodist University (SMU), Dallas, TX (United States)]. E-mail: JLL@smu.edu

    2008-07-01

    In this study, the natural convection inside a fluid filled, enclosure containing several solid obstructions and being heated from the side is modeled and numerically simulated. The solid obstructions are equally spaced, conducting, and disconnected square blocks. The mathematical model is based on the balance equations of mass, momentum and energy, which are then solved numerically via the finite-volume method with the SIMPLEST algorithm and the HYBRID scheme. The effects of varying the solid-fluid thermal conductivity ratio (K), the fluid volume-fraction or porosity ({phi}), the number of solid blocks (N) and the heating strength (represented by the Rayleigh number, Ra) of the enclosure on the Nusselt number based on the surface-averaged heat transfer coefficient along the heated wall of the enclosure are studied. The results indicate a competing effect caused by the proximity of the solid blocks to the heated and cooled walls, vis-a-vis hindering the boundary layer growth, hence reducing the heat transfer effectiveness, and at the same time enhancing the heat transfer when the blocks' thermal conductivity is larger than that of the fluid. An analytical estimate of the minimum number of blocks beyond which the convection hindrance becomes predominant is presented and validated by the numerical results. (author)

  3. Haplotype block structure is conserved across mammals.

    Directory of Open Access Journals (Sweden)

    Victor Guryev

    2006-07-01

    Full Text Available Genetic variation in genomes is organized in haplotype blocks, and species-specific block structure is defined by differential contribution of population history effects in combination with mutation and recombination events. Haplotype maps characterize the common patterns of linkage disequilibrium in populations and have important applications in the design and interpretation of genetic experiments. Although evolutionary processes are known to drive the selection of individual polymorphisms, their effect on haplotype block structure dynamics has not been shown. Here, we present a high-resolution haplotype map for a 5-megabase genomic region in the rat and compare it with the orthologous human and mouse segments. Although the size and fine structure of haplotype blocks are species dependent, there is a significant interspecies overlap in structure and a tendency for blocks to encompass complete genes. Extending these findings to the complete human genome using haplotype map phase I data reveals that linkage disequilibrium values are significantly higher for equally spaced positions in genic regions, including promoters, as compared to intergenic regions, indicating that a selective mechanism exists to maintain combinations of alleles within potentially interacting coding and regulatory regions. Although this characteristic may complicate the identification of causal polymorphisms underlying phenotypic traits, conservation of haplotype structure may be employed for the identification and characterization of functionally important genomic regions.

  4. Partial transmission block production for real efficient method of block and MLC

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ji Min; Park, Ju Young; Ju, Sang Kyu; Park, Jong Ho [Dept. of Radiation Oncology, Samsung Medical Center, Sunkyunkwan University, Seoul (Korea, Republic of)

    2004-09-15

    The Vaginal, the urethra, the vulva and anal cancer avoid the many dose to femur head and the additional treatment is necessary in inguinal LN. The partial transmission block to use inguinal LN addition there is to a method which it treats and produce partial transmission block a method and the MLC which to it analyzes. The Inguinal the LN treatment patient partial transmission it used block and the MLC in the object and with solid water phantom with the patient it reappeared the same depth. In order to analyze the error of the junction the EDR2 (Extended dose range, the Kodak and the U.S) it used the Film and it got film scanner it got the beam profile. The partial transmission block and the MLC bias characteristic, accuracy and stability of production for, it shared at hour and comparison it analyzed. The partial the transmission block compares in the MLC and the block production is difficult and production hour also above 1 hours. The custom the block the place where it revises the error of the junction is a difficult problem. If use of the MLC the fabrication will be break and only the periodical calibration of the MLC it will do and it will be able to use easily. The Inguinal there is to LN treatment and partial transmission block and the MLC there is efficiency of each one but there is a place where the junction of block for partial transmission block the production hour is caught long and it fixes and a point where the control of the block is difficult. Like this problem it transfers with the MLC and if it treats, it means the effective treatment will be possible.

  5. Quadratus Lumborum Block as an Alternative to Lumbar Plexus Block for Hip Surgery: A Report of 2 Cases.

    Science.gov (United States)

    La Colla, Luca; Ben-David, Bruce; Merman, Rita

    2017-01-01

    Quadratus lumborum (QL) block was first described several years ago, but few articles have been published regarding this technique, for the most part case series involving abdominal surgery. We report 2 cases of prolonged, extensive block of thoracic and lumbar dermatomes after QL block in patients undergoing different hip surgery procedures for whom QL block was used in place of lumbar plexus block. Further prospective studies comparing these 2 techniques are necessary to better characterize the role of QL block in hip surgery.

  6. Understanding dwarf galaxies as galactic building blocks

    CERN Document Server

    Tosi, M P

    2003-01-01

    This is a summary of a general discussion held during the third EuroConference on galaxy evolution. Various observational features of the stellar populations in present--day dwarf galaxies were presented to introduce the discussion on the possibility that these systems be the main building blocks of spiral and elliptical galaxies. Many people in the audience turned out to think that the inconsistencies among the observed properties of large and dwarf galaxies are too many to believe that the former are built up only by means of successive accretions of the latter. However, theorists of hierarchical galaxy formation suggested that present--day dwarfs are not representative of the galactic building blocks, which may be completely invisible nowadays. Some of them suggested that, contrary to what is usually assumed in hierarchical modelling, the actual building blocks were still fully gaseous systems when their major mergers occurred. If this is the case, then most of the inconsistencies can be overcome, and the ...

  7. Rapid ordering of block copolymer thin films

    Science.gov (United States)

    Majewski, Pawel W.; Yager, Kevin G.

    2016-10-01

    Block-copolymers self-assemble into diverse morphologies, where nanoscale order can be finely tuned via block architecture and processing conditions. However, the ultimate usage of these materials in real-world applications may be hampered by the extremely long thermal annealing times—hours or days—required to achieve good order. Here, we provide an overview of the fundamentals of block-copolymer self-assembly kinetics, and review the techniques that have been demonstrated to influence, and enhance, these ordering kinetics. We discuss the inherent tradeoffs between oven annealing, solvent annealing, microwave annealing, zone annealing, and other directed self-assembly methods; including an assessment of spatial and temporal characteristics. We also review both real-space and reciprocal-space analysis techniques for quantifying order in these systems.

  8. Concentration Dependent Structure of Block Copolymer Solutions

    Science.gov (United States)

    Choi, Soohyung; Bates, Frank S.; Lodge, Timothy P.

    2015-03-01

    Addition of solvent molecules into block copolymer can induce additional interactions between the solvent and both blocks, and therefore expands the range of accessible self-assembled morphologies. In particular, the distribution of solvent molecules plays a key role in determining the microstructure and its characteristic domain spacing. In this study, concentration dependent structures formed by poly(styrene-b-ethylene-alt-propylene) (PS-PEP) solution in squalane are investigated using small-angle X-ray scattering. This reveals that squalane is essentially completely segregated into the PEP domains. In addition, the conformation of the PS block changes from stretched to nearly fully relaxed (i.e., Gaussian conformation) as amounts of squalane increases. NRF

  9. Additive-driven assembly of block copolymers

    Science.gov (United States)

    Lin, Ying; Daga, Vikram; Anderson, Eric; Watkins, James

    2011-03-01

    One challenge to the formation of well ordered hybrid materials is the incorporation of nanoscale additives including metal, semiconductor and dielectric nanoparticles at high loadings while maintaining strong segregation. Here we describe the molecular and functional design of small molecule and nanoparticle additives that enhance phase segregation in their block copolymer host and enable high additive loadings. Our approach includes the use of hydrogen bond interactions between the functional groups on the additive or particle that serve as hydrogen bond donors and one segment of the block copolymer containing hydrogen bond acceptors. Further, the additives show strong selectively towards the targeted domains, leading to enhancements in contrast between properties of the phases. In addition to structural changes, we explore how large changes in the thermal and mechanical properties occur upon incorporation of the additives. Generalization of this additive-induced ordering strategy to various block copolymers will be discussed.

  10. Effects of 4X4 Block Scheduling

    Directory of Open Access Journals (Sweden)

    R. Brian Cobb

    1999-02-01

    Full Text Available The effects of a 4 X 4 block scheduling program in a middle school on a variety of student measures were investigated. These measures included standardized achievement tests in mathematics, reading, and writing, cumulative and semester grades in middle school and high school, attendance rates, and enrollment rates in advanced high school courses (in mathematics only. The block scheduling program had been in effect for four years allowing analyses of current middle and high school students who had experienced a minimum of one and one-half years of block scheduling while in middle school. The primary research design was a post-test only, matched pairs design. Students were matched on school characteristics, gender, ethnicity, grade level, and 5th grade standardized reading scores. Results were relatively consistent with the extant literature and generally positive.

  11. Radial expansion for spinning conformal blocks

    CERN Document Server

    Costa, Miguel; Hansen, Tobias; Penedones, João; Trevisani, Emilio

    2016-01-01

    This paper develops a method to compute any bosonic conformal block as a series expansion in the optimal radial coordinate introduced by Hogervorst and Rychkov. The method reduces to the known result when the external operators are all the same scalar operator, but it allows to compute conformal blocks for external operators with spin. Moreover, we explain how to write closed form recursion relations for the coefficients of the expansions. We study three examples of four point functions in detail: one vector and three scalars; two vectors and two scalars; two spin 2 tensors and two scalars. Finally, for the case of two external vectors, we also provide a more efficient way to generate the series expansion using the analytic structure of the blocks as a function of the scaling dimension of the exchanged operator.

  12. Performance of Laterite-Cement Blocks as Walling Units in Relation to Sandcrete Blocks

    Directory of Open Access Journals (Sweden)

    James Isiwu AGUWA

    2010-12-01

    Full Text Available A study of the performance of laterite-cement blocks as walling materials in relation to those of sandcrete was conducted, for the purpose of establishing a cheaper building material in Minna, Niger state, Nigeria and surrounding towns, in the present ever increasing cost of building material. An A-2-6 laterite according to the AASHTO classification system was stabilized with 0-10% cement content by weight of the soil at a constant interval of 2% to produce 20 blocks of size 100mm × 100mm × 100mm for each mix. One hundred laterite-cement blocks were produced, cured under laboratory conditions and subjected to compressive strength test at 7, 14, 21, and 28-days of age, in five applications for each cement mix ratio. The average compressive strength was determined from five blocks crushed in each mix at every age of curing and the same procedure was repeated using sandcrete blocks. At a common cement content of 6%, the compressive strengths, densities, water absorption and the cost per square metre of wall for both types of blocks were determined. The study recommends the use of laterite-cement blocks as walling materials in Minna and environs because it has better engineering properties and more economical with a saving of 30% per square metre of wall when compared with the use of sandcrete blocks.

  13. Biodegradable amphiphilic block copolymers containing functionalized PEO blocks:Controlled synthesis and biomedical potentials

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A series of controllable amphiphilic block copolymers composed of poly(ethylene oxide)(PEO) as the hydrophilic block and poly(ε-caprolactone)(PCL) as the hydrophobic block with the amino terminal group at the end of the PEO chain(PCL-b-PEO-NH2) were synthesized.Based on the further reaction of reactive amino groups,diblock copolymers with functional carboxyl groups(PCL-b-PEO-COOH) and functional compounds RGD(PCL-b-PEO-RGD) as well as the triblock copolymers with thermosensitive PNIPAAm blocks(PCL-b-PEO-b-PNIPAAM) were synthesized.The well-controlled structures of these copolymers with functional groups and blocks were characterized by gel permeation chromatography(GPC) and 1H NMR spectroscopy.These copolymers with functionalized hydrophilic blocks were fabricated into microspheres for the examination of biofunctions via cell culture experiments and in vitro drug release.The results indicated the significance of introducing functional groups(e.g.,NH2,COOH and RGD) into the end of the hydrophilic block of amphiphilic block copolymers for biomedical potentials in tissue engineering and controlled drug release.

  14. Block by Block: Neighborhoods and Public Policy on Chicago's West Side. Historical Studies of Urban America

    Science.gov (United States)

    Seligman, Amanda I.

    2005-01-01

    In the decades following World War II, cities across the United States saw an influx of African American families into otherwise homogeneously white areas. This racial transformation of urban neighborhoods led many whites to migrate to the suburbs, producing the phenomenon commonly known as white flight. In "Block by Block," Amanda I. Seligman…

  15. Blending of styrene-block-butadiene-block-styrene copolymer with sulfonated vinyl aromatic polymers

    NARCIS (Netherlands)

    Ruggeri, Giacomo; Passaglia, Elisa; Giorgi, Ivan; Picchioni, Francesco; Aglietto, Mauro

    2001-01-01

    Different polymers containing sulfonic groups attached to the phenyl rings were prepared by sulfonation of polystyrene (PS) and styrene-block-(ethylene-co-1-butene)-block-styrene (SEBS). The sulfonation degree (SD) was varied between 1 and 20 mol% of the styrene units. Polyphase materials containing

  16. Production blocking and idea generation : Does blocking interfere with cognitive processes?

    NARCIS (Netherlands)

    Nijstad, BA; Stroebe, W; Lodewijkx, HFM

    2003-01-01

    Production blocking (group members must take turns expressing their ideas) is an important cause of productivity loss in brainstorming groups. However, it is not yet clear why production blocking has this detrimental effect. We hypothesized that delays between the generation and articulation of idea

  17. Lidocaine block of cardiac sodium channels.

    Science.gov (United States)

    Bean, B P; Cohen, C J; Tsien, R W

    1983-05-01

    Lidocaine block of cardiac sodium channels was studied in voltage-clamped rabbit purkinje fibers at drug concentrations ranging from 1 mM down to effective antiarrhythmic doses (5-20 muM). Dose-response curves indicated that lidocaine blocks the channel by binding one-to-one, with a voltage-dependent K(d). The half-blocking concentration varied from more than 300 muM, at a negative holding potential where inactivation was completely removed, to approximately 10 muM, at a depolarized holding potential where inactivation was nearly complete. Lidocaine block showed prominent use dependence with trains of depolarizing pulses from a negative holding potential. During the interval between pulses, repriming of I (Na) displayed two exponential components, a normally recovering component (tauless than 0.2 s), and a lidocaine-induced, slowly recovering fraction (tau approximately 1-2 s at pH 7.0). Raising the lidocaine concentration magnified the slowly recovering fraction without changing its time course; after a long depolarization, this fraction was one-half at approximately 10 muM lidocaine, just as expected if it corresponded to drug-bound, inactivated channels. At less than or equal to 20 muM lidocaine, the slowly recovering fraction grew exponentially to a steady level as the preceding depolarization was prolonged; the time course was the same for strong or weak depolarizations, that is, with or without significant activation of I(Na). This argues that use dependence at therapeutic levels reflects block of inactivated channels, rather than block of open channels. Overall, these results provide direct evidence for the "modulated-receptor hypothesis" of Hille (1977) and Hondeghem and Katzung (1977). Unlike tetrodotoxin, lidocaine shows similar interactions with Na channels of heart, nerve, and skeletal muscle.

  18. Nerve injury caused by mandibular block analgesia

    DEFF Research Database (Denmark)

    Hillerup, S; Jensen, Rigmor H

    2006-01-01

    Fifty-four injection injuries in 52 patients were caused by mandibular block analgesia affecting the lingual nerve (n=42) and/or the inferior alveolar nerve (n=12). All patients were examined with a standardized test of neurosensory functions. The perception of the following stimuli was assessed......: feather light touch, pinprick, sharp/dull discrimination, warm, cold, point location, brush stroke direction, 2-point discrimination and pain perception. Gustation was tested for recognition of sweet, salt, sour and bitter. Mandibular block analgesia causes lingual nerve injury more frequently than...

  19. Wilson loop invariants from WN conformal blocks

    Directory of Open Access Journals (Sweden)

    Oleg Alekseev

    2015-12-01

    Full Text Available Knot and link polynomials are topological invariants calculated from the expectation value of loop operators in topological field theories. In 3D Chern–Simons theory, these invariants can be found from crossing and braiding matrices of four-point conformal blocks of the boundary 2D CFT. We calculate crossing and braiding matrices for WN conformal blocks with one component in the fundamental representation and another component in a rectangular representation of SU(N, which can be used to obtain HOMFLY knot and link invariants for these cases. We also discuss how our approach can be generalized to invariants in higher-representations of WN algebra.

  20. Conformal blocks in the QCD Pomeron formalism

    CERN Document Server

    Navelet, H

    1996-01-01

    The conformal invariance properties of the QCD Pomeron in the transverse plane allow us to give an explicit analytical expression for the conformal eigenvectors in the mixed representation in terms of two conformal blocks, each block being the product of an holomorphic times an antiholomorphic function. This property is used to give an exact expression for various functions of interest, the Pomeron amplitude in both momentum and impact-parameter variables, the QCD dipole multiplicities and dipole-dipole cross-sections in the whole parameter space, and we recover the expression of the four-point gluon Green function given recently by Lipatov

  1. Block floating point for radar data

    DEFF Research Database (Denmark)

    Christensen, Erik Lintz

    1999-01-01

    Integer, floating point, and block floating point (BFP) data formats are analyzed and compared in order to establish the mathematical tools for selection of an optimal format which fulfils the demands of high resolution radar (SAR) data to large dynamic range and adequate S/N. The analysis takes...... quantization noise and saturation distortion into account and concludes that it is preferred to use small blocks and a (new) modified BFP format applying fractional exponents. Data from the EMISAR radar system are applied to illustrate the merits of the different schemes....

  2. Ophthalmic regional blocks: management, challenges, and solutions

    Directory of Open Access Journals (Sweden)

    Palte HD

    2015-08-01

    Full Text Available Howard D Palte Department of Anesthesiology, Perioperative Medicine and Pain Management, Miller School of Medicine, University of Miami, Miami, FL, USA Abstract: In the past decade ophthalmic anesthesia has witnessed a major transformation. The sun has set on the landscape of ophthalmic procedures performed under general anesthesia at in-hospital settings. In its place a new dawn has ushered in the panorama of eye surgeries conducted under regional and topical anesthesia at specialty eye care centers. The impact of the burgeoning geriatric population is that an increasing number of elderly patients will present for eye surgery. In order to accommodate increased patient volumes and simultaneously satisfy administrative initiatives directed at economic frugality, administrators will seek assistance from anesthesia providers in adopting measures that enhance operating room efficiency. The performance of eye blocks in a holding suite meets many of these objectives. Unfortunately, most practicing anesthesiologists resist performing ophthalmic regional blocks because they lack formal training. In future, anesthesiologists will need to block eyes and manage common medical conditions because economic pressures will eliminate routine preoperative testing. This review addresses a variety of topical issues in ophthalmic anesthesia with special emphasis on cannula and needle-based blocks and the new-generation antithrombotic agents. In a constantly evolving arena, the sub-Tenon’s block has gained popularity while the deep angulated intraconal (retrobulbar block has been largely superseded by the shallower extraconal (peribulbar approach. Improvements in surgical technique have also impacted anesthetic practice. For example, phacoemulsification techniques facilitate the conduct of cataract surgery under topical anesthesia, and suture-free vitrectomy ports may cause venous air embolism during air/fluid exchange. Hyaluronidase is a useful adjuvant because it

  3. A solar air apartment block, Gothenburg, Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Nordstrom, C.

    1999-07-01

    A double envelope solar air system was installed in a 1950s three-storey apartment block when it was renovated in 1986. The system saves 40% compared to identical conventionally renovated buildings, thanks to the following: The south-facing side of the roof has been converted to a 350 m{sup 2} solar air collector. An extra insulated facade with an integrated air-space of 900 m{sup 2} has been added to all surrounding walls. A DHW system including a 12 m{sup 3} storage tank has been added in order to provide solar heated water to four blocks (96 apartments) during the summer. (author)

  4. Superconvergence of tricubic block finite elements

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper, we first introduce interpolation operator of projection type in three dimen- sions, from which we derive weak estimates for tricubic block finite elements. Then using the estimate for the W 2, 1-seminorm of the discrete derivative Green’s function and the weak estimates, we show that the tricubic block finite element solution uh and the tricubic interpolant of projection type Πh3u have superclose gradient in the pointwise sense of the L∞-norm. Finally, this supercloseness is applied to superconvergence analysis, and the global superconvergence of the finite element approximation is derived.

  5. Quantization of the space of conformal blocks

    CERN Document Server

    Mukhin, E

    1997-01-01

    We consider the discrete Knizhnik-Zamolodchikov connection (qKZ) associated to $gl(N)$, defined in terms of rational R-matrices. We prove that under certain resonance conditions, the qKZ connection has a non-trivial invariant subbundle which we call the subbundle of quantized conformal blocks. The subbundle is given explicitly by algebraic equations in terms of the Yangian $Y(gl(N))$ action. The subbundle is a deformation of the subbundle of conformal blocks in CFT. The proof is based on an identity in the algebra with two generators $x,y$ and defining relation $xy=yx+yy$.

  6. Round Gating for Low Energy Block Ciphers

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Bogdanov, Andrey; Regazzoni, Francesco;

    2016-01-01

    Pushed by the pervasive diffusion of devices operated by battery or by the energy harvested, energy has become one of the most important parameter to be optimized for embedded systems. Particularly relevant would be to optimize the energy consumption of security primitives. In this paper we explore...... design techniques for implementing block ciphers in a low energy fashion. We concentrate on round based implementation and we discuss how gating, applied at round level can affect and improve the energy consumption of the most common lightweight block cipher currently used in the internet of things...

  7. Heparin-containing block copolymers, Part I: Surface characterization

    NARCIS (Netherlands)

    Vulić, I.; Pijpers, A.P.; Okano, T.; Kim, S.W.; Feijen, J.

    1993-01-01

    Newly synthesized heparin-containing block copolymers, consisting of a hydrophobic block of polystyrene (PS), a hydrophilic spacer-block of poly(ethylene oxide) (PEO) and covalently bound heparin (Hep) as bioactive block, were coated on aluminium, glass, polydimethylsiloxane (PDMS), PS or Biomer sub

  8. 30 CFR 250.511 - Traveling-block safety device.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Traveling-block safety device. 250.511 Section... Traveling-block safety device. All units being used for well-completion operations that have both a traveling block and a crown block must be equipped with a safety device that is designed to prevent...

  9. 30 CFR 250.611 - Traveling-block safety device.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Traveling-block safety device. 250.611 Section... Traveling-block safety device. After May 31, 1989, all units being used for well-workover operations which have both a traveling block and a crown block shall be equipped with a safety device which is...

  10. Neuraxial block and postoperative epidural analgesia

    DEFF Research Database (Denmark)

    Leslie, K; McIlroy, D; Kasza, J

    2016-01-01

    BACKGROUND: We assessed associations between intraoperative neuraxial block and postoperative epidural analgesia, and a composite primary outcome of death or non-fatal myocardial infarction, at 30 days post-randomization in POISE-2 Trial subjects. METHODS: 10 010 high-risk noncardiac surgical pat...

  11. Finding maximum JPEG image block code size

    Science.gov (United States)

    Lakhani, Gopal

    2012-07-01

    We present a study of JPEG baseline coding. It aims to determine the minimum storage needed to buffer the JPEG Huffman code bits of 8-bit image blocks. Since DC is coded separately, and the encoder represents each AC coefficient by a pair of run-length/AC coefficient level, the net problem is to perform an efficient search for the optimal run-level pair sequence. We formulate it as a two-dimensional, nonlinear, integer programming problem and solve it using a branch-and-bound based search method. We derive two types of constraints to prune the search space. The first one is given as an upper-bound for the sum of squares of AC coefficients of a block, and it is used to discard sequences that cannot represent valid DCT blocks. The second type constraints are based on some interesting properties of the Huffman code table, and these are used to prune sequences that cannot be part of optimal solutions. Our main result is that if the default JPEG compression setting is used, space of minimum of 346 bits and maximum of 433 bits is sufficient to buffer the AC code bits of 8-bit image blocks. Our implementation also pruned the search space extremely well; the first constraint reduced the initial search space of 4 nodes down to less than 2 nodes, and the second set of constraints reduced it further by 97.8%.

  12. Charge Transport in Conjugated Block Copolymers

    Science.gov (United States)

    Smith, Brandon; Le, Thinh; Lee, Youngmin; Gomez, Enrique

    Interest in conjugated block copolymers for high performance organic photovoltaic applications has increased considerably in recent years. Polymer/fullerene mixtures for conventional bulk heterojunction devices, such as P3HT:PCBM, are severely limited in control over interfaces and domain length scales. In contrast, microphase separated block copolymers self-assemble to form lamellar morphologies with alternating electron donor and acceptor domains, thereby maximizing electronic coupling and local order at interfaces. Efficiencies as high as 3% have been reported in solar cells for one block copolymer, P3HT-PFTBT, but the details concerning charge transport within copolymers have not been explored. To fill this gap, we probed the transport characteristics with thin-film transistors. Excellent charge mobility values for electron transport have been observed on aluminum source and drain contacts in a bottom gate, bottom contact transistor configuration. Evidence of high mobility in ordered PFTBT phases has also been obtained following thermal annealing. The insights gleaned from our investigation serve as useful guideposts, revealing the significance of the interplay between charge mobility, interfacial order, and optimal domain size in organic block copolymer semiconductors.

  13. Iron Blocks of CMS Magnet Barrel Yoke.

    CERN Multimedia

    2000-01-01

    On the occasion of presenting the CMS Award 2000 to Deggendorfer Werft und Eisenbau GmbH the delivered blocks were inspected at CERN Point 5. From left to right: H. Gerwig (CERN, CMS Magnet Barrel Yoke Coordinator), G. Waurick (CERN), F. Leher (DWE, Project Engineer) and W. Schuster (DWE, Project Manager).

  14. Weight modules over some Block algebras

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper, the Harish-Chandra modules and Verma modules over Block algebra L[G] are investigated. More precisely, the irreducibility of the Verma modules over L[G] is completely determined, and the Harish-Chandra modules over L[Z] are classified.

  15. Weight modules over some Block algebras

    Institute of Scientific and Technical Information of China (English)

    L(U) RenCai

    2009-01-01

    In this paper,the Harish-Chandra modules and Verma modules over Block algebra (e)[G]are investigated.More precisely,the irreducibility of the Verma modules over (e)[G]is completely determined,and the Harish-Chandra modules over (e)[Z]are classified.

  16. Seed Conformal Blocks in 4D CFT

    CERN Document Server

    Echeverri, Alejandro Castedo; Karateev, Denis; Serone, Marco

    2016-01-01

    We compute in closed analytical form the minimal set of "seed" conformal blocks associated to the exchange of generic mixed symmetry spinor/tensor operators in an arbitrary representation (l,\\bar l) of the Lorentz group in four dimensional conformal field theories. These blocks arise from 4-point functions involving two scalars, one (0,|l-\\bar l|) and one (|l-\\bar l|,0) spinors or tensors. We directly solve the set of Casimir equations, that can elegantly be written in a compact form for any (l,\\bar l), by using an educated ansatz and reducing the problem to an algebraic linear system. Various details on the form of the ansatz have been deduced by using the so called shadow formalism. The complexity of the conformal blocks depends on the value of p=|l-\\bar l | and grows with p, in analogy to what happens to scalar conformal blocks in d even space-time dimensions as d increases. These results open the way to bootstrap 4-point functions involving arbitrary spinor/tensor operators in four dimensional conformal f...

  17. Block Toeplitz operators with rational symbols (II)

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, In Sung [Department of Mathematics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Woo Young [Department of Mathematics, Seoul National University, Seoul 151-742 (Korea, Republic of)], E-mail: ishwang@skku.edu, E-mail: wylee@math.snu.ac.kr

    2008-09-26

    In this paper we derive a formula for the rank of the self-commutator of hyponormal block Toeplitz operators T{sub {phi}} with matrix-valued rational symbols {phi} in L{sup {infinity}}(C{sup nxn}) via the classical Hermite-Fejer interpolation problem.

  18. Block Toeplitz operators with rational symbols

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, In Sung [Department of Mathematics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Woo Young [Department of Mathematics, Seoul National University, Seoul 151-742 (Korea, Republic of)], E-mail: ishwang@skku.edu, E-mail: wylee@math.snu.ac.kr

    2008-05-09

    In this paper we show that the hyponormality of block Toeplitz operators T{sub {phi}} with matrix-valued rational symbols {phi} in L{sup {infinity}}(C{sup nxn}) is completely determined by the tangential Hermite-Fejer interpolation problem.

  19. Chiral Block Copolymer Structures for Metamaterial Applications

    Science.gov (United States)

    2015-01-27

    MONITOR’S REPORT NUMBER(S) AOARD-114078 12. DISTRIBUTION/AVAILABILITY STATEMENT Distribution A: Approved for public release. Distribtion is...researchers focused o synthesis and processing, morphology and physical characterization of chiral block copolymer (BCP) materials. Such materials a...developed a platform process technology that can fabricate novel netwo morphologies from initial bicontinuous cubic phases through supergroup/subgroup

  20. Who Is at Risk for Heart Block?

    Science.gov (United States)

    ... degree heart block caused by an overly active vagus nerve. You have one vagus nerve on each side of your body. These nerves ... the way to your abdomen. Activity in the vagus nerve slows the heart rate. Rate This Content: NEXT >> ...

  1. Improved cryptanalysis of the block cipher KASUMI

    DEFF Research Database (Denmark)

    Jia, Keting; Li, Leibo; Rechberger, Christian;

    2013-01-01

    KASUMI is a block cipher which consists of eight Feistel rounds with a 128-bit key. Proposed more than 10 years ago, the confidentiality and integrity of 3G mobile communications systems depend on the security of KASUMI. In the practically interesting single key setting, only up to 6 rounds have...

  2. Nylon 46-polytetramethylene oxide segmented block copolymers

    NARCIS (Netherlands)

    Gaymans, R.J.; Schwering, P.; Haan, de J.L.

    1989-01-01

    Block copolymers were synthesized from amine-terminated polytetramethylene oxide (PMTO) (Mw 800 and 1130) and polyamide 4,6 salt. First prepolymers were prepared at 200–210°C in the presence of a solvent (pyrrolidone). The prepolymers were postcondensed at 255°C (where possible in the solid state) t

  3. Prenatal diagnosis of congenital complete heart block.

    Science.gov (United States)

    Costa, Patrícia; Carriço, Ana; Ramalho, Carla; Matias, Alexandra; Monterroso, José; Areias, José Carlos

    2007-06-01

    Congenital complete heart block (CHB) is a conduction defect with an incidence in the general population of 1/15,000 to 1/22,000 live births. It is frequently associated with structural heart defects or maternal autoimmune disease. We describe a case of CHB associated with maternal systemic lupus erythematosus and review our previous cases and experience of CHB.

  4. Defying Gravity Using Jenga[TM] Blocks

    Science.gov (United States)

    Tan, Yin-Soo; Yap, Kueh-Chin

    2007-01-01

    This paper describes how Jenga[TM] blocks can be used to demonstrate the physics of an overhanging tower that appears to defy gravity. We also propose ideas for how this demonstration can be adapted for the A-level physics curriculum. (Contains 8 figures and 1 table.)

  5. BLOCK BASED NEWTON-LIKE BLENDING INTERPOLATION

    Institute of Scientific and Technical Information of China (English)

    Qian-jin Zhao; Jie-qing Tan

    2006-01-01

    Newton's polynomial interpolation may be the favourite linear interpolation in the sense that it is built up by means of the divided differences which can be calculated recursively and produce useful intermediate results. However Newton interpolation is in fact point based interpolation since a new interpolating polynomial with one more degree is obtained by adding a new support point into the current set of support points once at a time. In this paper we extend the point based interpolation to the block based interpolation. Inspired by the idea of the modern architectural design, we first divide the original set of support points into some subsets (blocks), then construct each block by using whatever interpolation means, linear or rational and finally assemble these blocks by Newton's method to shape the whole interpolation scheme. Clearly our method offers many flexible interpolation schemes for choices which include the classical Newton's polynomial interpolation as its special case. A bivariate analogy is also discussed and numerical examples are given to show the effectiveness of our method.

  6. CLINICAL PHARMACOKINETICS OF NEUROMUSCULAR BLOCKING-DRUGS

    NARCIS (Netherlands)

    AGOSTON, S; VANDENBROM, RHG; WIERDA, JMKH

    1992-01-01

    Neuromuscular blocking agents provide muscle relaxation for a great variety of surgical procedures with light planes of general anaesthesia. Besides having a significant impact in the development of anaesthesia and surgery, these agents continue to play an important role as pharmacological tools in

  7. Topological structures of boundary value problems in block elements

    Science.gov (United States)

    Babeshko, V. A.; Evdokimova, O. V.; Babeshko, O. M.

    2016-10-01

    Block structures are considered; a boundary value problem for a system of inhomogeneous partial differential equations with constant coefficients is formulated in each block of a structure. The problem of matching solutions to boundary value problems in blocks with each other by topological study of the properties of solutions in the block structure is examined in the conditions of correct solvability of boundary value problems in blocks of the block structure. Some new properties of solutions to boundary value problems in block structures are found that are important for applications.

  8. Combined KHFAC + DC nerve block without onset or reduced nerve conductivity after block

    Science.gov (United States)

    Franke, Manfred; Vrabec, Tina; Wainright, Jesse; Bhadra, Niloy; Bhadra, Narendra; Kilgore, Kevin

    2014-10-01

    Objective. Kilohertz frequency alternating current (KHFAC) waveforms have been shown to provide peripheral nerve conductivity block in many acute and chronic animal models. KHFAC nerve block could be used to address multiple disorders caused by neural over-activity, including blocking pain and spasticity. However, one drawback of KHFAC block is a transient activation of nerve fibers during the initiation of the nerve block, called the onset response. The objective of this study is to evaluate the feasibility of using charge balanced direct current (CBDC) waveforms to temporarily block motor nerve conductivity distally to the KHFAC electrodes to mitigate the block onset-response. Approach. A total of eight animals were used in this study. A set of four animals were used to assess feasibility and reproducibility of a combined KHFAC + CBDC block. A following randomized study, conducted on a second set of four animals, compared the onset response resulting from KHFAC alone and combined KHFAC + CBDC waveforms. To quantify the onset, peak forces and the force-time integral were measured during KHFAC block initiation. Nerve conductivity was monitored throughout the study by comparing muscle twitch forces evoked by supra-maximal stimulation proximal and distal to the block electrodes. Each animal of the randomized study received at least 300 s (range: 318-1563 s) of cumulative dc to investigate the impact of combined KHFAC + CBDC on nerve viability. Main results. The peak onset force was reduced significantly from 20.73 N (range: 18.6-26.5 N) with KHFAC alone to 0.45 N (range: 0.2-0.7 N) with the combined CBDC and KHFAC block waveform (p < 0.001). The area under the force curve was reduced from 6.8 Ns (range: 3.5-21.9 Ns) to 0.54 Ns (range: 0.18-0.86 Ns) (p < 0.01). No change in nerve conductivity was observed after application of the combined KHFAC + CBDC block relative to KHFAC waveforms. Significance. The distal application of CBDC can significantly reduce or even

  9. Solving block linear systems with low-rank off-diagonal blocks is easily parallelizable

    Energy Technology Data Exchange (ETDEWEB)

    Menkov, V. [Indiana Univ., Bloomington, IN (United States)

    1996-12-31

    An easily and efficiently parallelizable direct method is given for solving a block linear system Bx = y, where B = D + Q is the sum of a non-singular block diagonal matrix D and a matrix Q with low-rank blocks. This implicitly defines a new preconditioning method with an operation count close to the cost of calculating a matrix-vector product Qw for some w, plus at most twice the cost of calculating Qw for some w. When implemented on a parallel machine the processor utilization can be as good as that of those operations. Order estimates are given for the general case, and an implementation is compared to block SSOR preconditioning.

  10. Optimization of Macro Block Size for Adaptive Rood Pattern Search Block Matching Method in Motion Estimation

    Directory of Open Access Journals (Sweden)

    Prof. Nar Singh

    2016-05-01

    Full Text Available In area of video compression, Motion Estimation is one of the most important modules and play an important role to design and implementation of any the video encoder. It consumes more than 85% of video encoding time due to searching of a candidate block in the search window of the reference frame. Various block matching methods have been developed to minimize the search time. In this context, Adaptive Rood Pattern Search is one of the less expensive block matching methods, which is widely acceptable for better Motion Estimation in video data processing. In this paper we have proposed to optimize the macro block size used in adaptive rood pattern search method for improvement in motion estimation.

  11. Essential Building Blocks of Human Nature

    CERN Document Server

    Frey, Ulrich J; Willführ, Kai P

    2011-01-01

    To understand why we humans are as we are, it is necessary to look at the essential building blocks that comprise our nature. The foundations of this structure are our evolutionary origins as primates and our social roots. Upon these rest features such as our emotions, language and aesthetic preferences, with our self-perceptions, self-deceptions and thirst for knowledge right at the top. The unifying force holding these blocks together is evolutionary theory. Evolution provides a deeper understanding of human nature and, in particular, of the common roots of these different perspectives. To build a reliable and coherent model of man, leading authors from fields as diverse as primatology, anthropology, neurobiology and philosophy have joined forces to present essays  each describing their own expert perspective. Together they provide a convincing and complete picture of our own human nature.

  12. Time and Spacetime: The Crystallizing Block Universe

    CERN Document Server

    Ellis, George F R

    2009-01-01

    The nature of the future is completely different from the nature of the past. When quantum effects are significant, the future shows all the signs of quantum weirdness, including duality, uncertainty, and entanglement. With the passage of time, after the time-irreversible process of state-vector reduction has taken place, the past emerges, with the previous quantum uncertainty replaced by the classical certainty of definite particle identities and states. The present time is where this transition largely takes place, but the process does not take place uniformly: Evidence from delayed choice and related experiments shows that isolated patches of quantum indeterminacy remain, and that their transition from probability to certainty only takes place later. Thus, when quantum effects are significant, the picture of a classical Evolving Block Universe (`EBU') cedes place to one of a Crystallizing Block Universe (`CBU'), which reflects this quantum transition from indeterminacy to certainty, while nevertheless rese...

  13. Enantiopure cyclopentane building blocks from iridoid glucosides

    DEFF Research Database (Denmark)

    Rasmussen, Jon Holbech

    building blocks in a short and efficient way. Two enantiopure carbocyclic homo-N-nucleosides, 382 and 391, were synthesised from 352. In another approach, catalpol (5) was transformed into cyclopentane derivative 59. Selective protection of 59, a subsequent coupling sequence with 6-iodopurine......The main objective of this work has been to investigate the use of the plant metabolites iridoid glucosides as starting materials in the synthesis of versatile cyclopentanoid building blocks. With the aim of isolating the iridoid glucoside catalpol (5) several species of the genus Scutellaria, i...... tetrabutylammonium salt 339 and a final deprotection/substitution step, afforded homo-N-nucleoside 359. Iridolactone 369 was prepared through a third sequence, and treatment of 369 with ammonia in methanol gave the a,b-unsaturated cyclopentene amide 370. A fourth sequence starting with 236 led to iridoid alcohol 396...

  14. Porous polymers based on aryleneethynylene building blocks.

    Science.gov (United States)

    Bunz, Uwe H F; Seehafer, Kai; Geyer, Florian L; Bender, Markus; Braun, Ingo; Smarsly, Emanuel; Freudenberg, Jan

    2014-09-01

    Porous conjugated polymers are synthesized by metal-catalyzed coupling reactions. The progress for porous polymers when planar or tetrahedral building blocks are connected by alkyne units into novel materials is highlighted. The most prominent reaction for the buildup of the microporous alkyne-bridged polymers is the Sonogashira reaction, connecting alkynes to aromatic iodides or bromides. The availability of the building blocks and the potency of the Sonogashira reaction allow preparing a large variety of intrinsically porous polymeric materials, in which rigid struts connect multipronged centers. The microporous polymers are used as catalysts and as storage materials for gases and sensors. Postfunctionalization schemes, understanding of structure-property relationships, and the quest for high porosity are pertinent.

  15. Gauge Blocks – A Zombie Technology

    Science.gov (United States)

    Doiron, Ted

    2008-01-01

    Gauge blocks have been the primary method for disseminating length traceability for over 100 years. Their longevity was based on two things: the relatively low cost of delivering very high accuracy to users, and the technical limitation that the range of high precision gauging systems was very small. While the first reason is still true, the second factor is being displaced by changes in measurement technology since the 1980s. New long range sensors do not require master gauges that are nearly the same length as the part being inspected, and thus one of the primary attributes of gauge blocks, wringing stacks to match the part, is no longer needed. Relaxing the requirement that gauges wring presents an opportunity to develop new types of end standards that would increase the accuracy and usefulness of gauging systems. PMID:27096119

  16. Neurologic complication after anterior sciatic nerve block.

    Science.gov (United States)

    Shah, Shruti; Hadzic, Admir; Vloka, Jerry D; Cafferty, Maureen S; Moucha, Calin S; Santos, Alan C

    2005-05-01

    The lack of reported complications related to lower extremity peripheral nerve blocks (PNBs) may be related to the relatively infrequent application of these techniques and to the fact that most such events go unpublished. Our current understanding of the factors that lead to neurologic complications after PNBs is limited. This is partly the result of our inability to conduct meaningful retrospective studies because of a lack of standard and objective monitoring and documentation procedures for PNBs. We report a case of permanent injury to the sciatic nerve after sciatic nerve block through the anterior approach and discuss mechanisms that may have led to the injury. Intraneural injection and nerve injury can occur in the absence of pain on injection and it may be heralded by high injection pressure (resistance).

  17. Infinite-degree-corrected stochastic block model

    DEFF Research Database (Denmark)

    Herlau, Tue; Schmidt, Mikkel Nørgaard; Mørup, Morten

    2014-01-01

    corrected stochastic block model as a nonparametric Bayesian model, incorporating a parameter to control the amount of degree correction that can then be inferred from data. Additionally, our formulation yields principled ways of inferring the number of groups as well as predicting missing links...... in the network that can be used to quantify the model’s predictive performance. On synthetic data we demonstrate that including the degree correction yields better performance on both recovering the true group structure and predicting missing links when degree heterogeneity is present, whereas performance......In stochastic block models, which are among the most prominent statistical models for cluster analysis of complex networks, clusters are defined as groups of nodes with statistically similar link probabilities within and between groups. A recent extension by Karrer and Newman [Karrer and Newman...

  18. Osmosis and thermodynamics explained by solute blocking

    CERN Document Server

    Nelson, Peter Hugo

    2016-01-01

    A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult's law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed, others can be tested experimentally or by simulation.

  19. On Combinatorial Expansions of Conformal Blocks

    CERN Document Server

    Marshakov, A; Morozov, A

    2009-01-01

    In a recent paper (arXiv:0906.3219) the representation of Nekrasov partition function in terms of nontrivial two-dimensional conformal field theory has been suggested. For non-vanishing value of the deformation parameter \\epsilon=\\epsilon_1+\\epsilon_2 the instanton partition function is identified with a conformal block of Liouville theory with the central charge c = 1+ 6\\epsilon^2/\\epsilon_1\\epsilon_2. If reversed, this observation means that the universal part of conformal blocks, which is the same for all two-dimensional conformal theories with non-degenerate Virasoro representations, possesses a non-trivial decomposition into sum over sets of the Young diagrams, different from the natural decomposition studied in conformal field theory. We provide some details about this intriguing new development in the simplest case of the four-point correlation functions.

  20. Osmosis and thermodynamics explained by solute blocking.

    Science.gov (United States)

    Nelson, Peter Hugo

    2017-01-01

    A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult's law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed; others can be tested experimentally or by simulation.

  1. PhenoBlocks: Phenotype Comparison Visualizations.

    Science.gov (United States)

    Glueck, Michael; Hamilton, Peter; Chevalier, Fanny; Breslav, Simon; Khan, Azam; Wigdor, Daniel; Brudno, Michael

    2016-01-01

    The differential diagnosis of hereditary disorders is a challenging task for clinicians due to the heterogeneity of phenotypes that can be observed in patients. Existing clinical tools are often text-based and do not emphasize consistency, completeness, or granularity of phenotype reporting. This can impede clinical diagnosis and limit their utility to genetics researchers. Herein, we present PhenoBlocks, a novel visual analytics tool that supports the comparison of phenotypes between patients, or between a patient and the hallmark features of a disorder. An informal evaluation of PhenoBlocks with expert clinicians suggested that the visualization effectively guides the process of differential diagnosis and could reinforce the importance of complete, granular phenotypic reporting.

  2. Hybrid, Nanoscale Phospholipid/Block Copolymer Vesicles

    Directory of Open Access Journals (Sweden)

    Bo Liedberg

    2013-09-01

    Full Text Available Hybrid phospholipid/block copolymer vesicles, in which the polymeric membrane is blended with phospholipids, display interesting self-assembly behavior, incorporating the robustness and chemical versatility of polymersomes with the softness and biocompatibility of liposomes. Such structures can be conveniently characterized by preparing giant unilamellar vesicles (GUVs via electroformation. Here, we are interested in exploring the self-assembly and properties of the analogous nanoscale hybrid vesicles (ca. 100 nm in diameter of the same composition prepared by film-hydration and extrusion. We show that the self-assembly and content-release behavior of nanoscale polybutadiene-b-poly(ethylene oxide (PB-PEO/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC hybrid phospholipid/block copolymer vesicles can be tuned by the mixing ratio of the amphiphiles. In brief, these hybrids may provide alternative tools for drug delivery purposes and molecular imaging/sensing applications and clearly open up new avenues for further investigation.

  3. Interventricular cardiac resynchronization with right ventricular apical pacing in a patient with Ebstein's defect.

    Science.gov (United States)

    Maffe, Stefano; Perucca, Antonello; Paffoni, Paola; Signorotti, Fabiana; Pardo, Nicolò Franchetti; Dellavesa, Pierfranco; Parravicini, Umberto; Zenone, Franco; Paino, Anna Maria; Bielli, Massimo; Carola, Federico; Zanetta, Marco

    2008-06-01

    We present the case of a patient with Ebstein's defect surgically corrected, and a complete right bundle branch block (RBBB) documented on echocardiogram. After an episode of near syncope due to a high-grade atrioventricular (AV) block, the patient was assisted with a bicameral DDDR pacemaker implanted with traditional right ventricular apical pacing. After the DDDR, and after stimulation with an AV delay of 180 ms, a narrow QRS complex was observed. Meanwhile, the typical left bundle branch block morphology of the right ventricular pacing and the native RBBB morphology were missing. The QRS complex narrowing persisted, even with physical activity and also with the heart rate progression. An echocardiographic study confirmed an improvement of the cardiac resynchronization parameters with this programmed stimulation.

  4. [Congenital atrioventricular block and maternal autoimmune diseases].

    Science.gov (United States)

    Herreman, G; Sauvaget, F; Généreau, T; Galezowski, N

    1990-01-01

    Congenital heart block is rare; it is acquired in utero, definitive and, more often than not, complete. It can be diagnosed by the appearance of fetal bradycardia around the 23rd week of gestation, during ultrasonographic monitoring of pregnancy. Heart block is usually associated with the presence of anti-Ro and/or anti-La antibodies in the mother's serum. These maternal immunological abnormalities can be isolated or associated with an autoimmune disease, usually systemic lupus erythematosus, but also Sjögren's syndrome, or more rarely still, an as yet unclassified connective tissue disease. Anti-Ro and anti-La antibodies cross the placental barrier and react with a fetal heart, leading to acute fetal myocarditis by the 17th week of gestation. When severe, it is lethal, otherwise it can result in degeneration and endocardial fibroelastosis, disrupting conduction and leading to congenital heart block. The ideal treatment would be prevention with corticosteroids. When the mother is Ro or La antibody-positive before pregnancy, elimination of these circulating antibodies can be attempted by treatment with 0.5 mg/kg body wt/d of prednisolone for 3 months. If the treatment is successful, corticotherapy can be prescribed early in the pregnancy to try to protect the fetus. However, there is not always a relationship between maternal anti-Ro antibodies and fetal heart block. If the Ro/La antibody-positive woman is already pregnant, but before her 17th week, it is possible to prescribe dexamethasone, which crosses the placenta and remains active, sometimes in association with plasmapheresis.

  5. Impedance Matched Absorptive Thermal Blocking Filters

    CERN Document Server

    Wollack, E J; Rostem, K; U-Yen, K

    2014-01-01

    We have designed, fabricated and characterized absorptive thermal blocking filters for cryogenic microwave applications. The transmission line filter's input characteristic impedance is designed to match $50\\,\\Omega$ and its response has been validated from 0-to-50\\,GHz. The observed return loss in the 0-to-20\\,GHz design band is greater than $20\\,$dB and shows graceful degradation with frequency. Design considerations and equations are provided that enable this approach to be scaled and modified for use in other applications.

  6. Gauge Blocks – A Zombie Technology

    OpenAIRE

    Doiron, Ted

    2008-01-01

    Gauge blocks have been the primary method for disseminating length traceability for over 100 years. Their longevity was based on two things: the relatively low cost of delivering very high accuracy to users, and the technical limitation that the range of high precision gauging systems was very small. While the first reason is still true, the second factor is being displaced by changes in measurement technology since the 1980s. New long range sensors do not require master gauges that are nearl...

  7. Floating asphalt blocks of the Dead Sea

    Energy Technology Data Exchange (ETDEWEB)

    Nissenbaum, A. (Weizmann Inst. of Science, Rehovot, Israel); Aizenshtat, Z.; Goldberg, M.

    1980-01-01

    Large blocks of mineral matter free (less than 0.1%) asphalt are occasionally found floating on the surface of the Dead Sea. Chemical, spectroscopic and isotopic data are given for the asphalt. The source of the asphalt is not accurately known, but presumably it represents mobilization of heavy viscous asphaltic masses at depth below the lake bottom into the floor of the lake. It may be released to the surface by earth tremors.

  8. General Structures of Block Based Interpolational Function

    Institute of Scientific and Technical Information of China (English)

    ZOU LE; TANG SHUO; Ma Fu-ming

    2012-01-01

    We construct general structures of one and two variable interpolation function,without depending on the existence of divided difference or inverse differences,and we also discuss the block based osculatory interpolation in one variable case.Clearly,our method offers many flexible interpolation schemes for choices.Error terms for the interpolation are determined and numerical examples are given to show the effectiveness of the results.

  9. SODART optical block of the SRG satellite

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Frederiksen, P.; Polny, Josef

    1998-01-01

    This paper describes the design and the successful integration of the optical block of the SODART telescopes to be flown on the Spectrum Roentgen Gamma satellite. The integration involves both the integration of the two high throughput x-ray telescopes as well as the objective crystal spectrometer....... The integrated unit meets all mechanical, thermal and optical specifications and it is now in safe storage in Moscow and awaits further integration procedures with the remaining satellite structure....

  10. Recurrent congenital heart block in neonatal lupus.

    Science.gov (United States)

    Escobar, Maria C; Gómez-Puerta, José A; Albert, Dimpna; Ferrer, Queralt; Girona, Josep

    2007-07-01

    Congenital heart block (CHB) is the main complication of neonatal lupus (NL) and is strongly associated with the presence of anti-SSA/Ro and anti-SSB/La antibodies. The recurrence of CHB in subsequent pregnancies in mothers with these antibodies is uncommon, occurring in approximately 15% of cases. We describe here a case of recurrent CHB in a previously asymptomatic mother with Sjögren syndrome and discuss the current strategies for the prevention and treatment of CHB in NL.

  11. Hyperkalemia-induced complete heart block

    Directory of Open Access Journals (Sweden)

    Alireza Baratloo

    2015-05-01

    Full Text Available Background: Potassium, as an extracellular ion, plays an important role in the electrophysiologic function of the myocardium and any change in extracellular concentration of this ion might have a marked impression upon myocyte electrophysiologic gain. High serum potassium levels are thought to impair pulse conduction in Purkinje fibers and ventricles more than that in the Atrioventricular (AV node. Therefore, although complete AV block can occur, it is a rare initial presentation. Case Report: We describe a 62-year-old man with a history of diabetes mellitus, ischemic heart disease and previous Coronary Artery Bypass Graft (CABG, who came to our emergency department due to generalized weakness starting 2 days before admission. The patient also had decreased force in lower limbs, exacerbating from the morning, and was finally diagnosed as a hyperkalemia-induced Complete Heart Block (CHB. It should also be noted that the patient responded dramatically to the administration of 10 mL of 10% calcium gluconate along with external pacing until potassium level correction became effective. Conclusion: In spite of the fact that Hyperkalemia can be associated with frequent Electrocardiogram (ECG abnormality, advanced heart blocks (second- and third-degree AV blocks are usually found only in patients with pre-existing heart failure, conduction abnormalities, or other cardiac diseases. Institution of effective treatment rapidly and forgiveness of traditional non-effective, time consumptive and sometimes risking full-adjustment modalities, such as sodium bicarbonate infusion or exchange resins that prevent their use in the emergent phase, can help minimize patient morbidity and mortality.

  12. Nanostructured Block Copolymer Coatings for Biofouling Inhibition

    Science.gov (United States)

    2015-06-30

    biofouling program contractors. 15. SUBJECT TERMS antifouling; coatings; block copolymers; IR nanoscale imaging ; biocides 16. SECURITY CLASSIFICATION OF...diagnostics and drug delivery. In our scanned probe microscopy studies on collaborator coatings and marine organisms, we have provided teamwork . We have...Studies of Organisms on model fouiants: • H. elegans studies 3. Testing of other contractor materials 4. Imaging technology. We applied our organic

  13. Thalamic pain alleviated by stellate ganglion block

    Science.gov (United States)

    Liao, Chenlong; Yang, Min; Liu, Pengfei; Zhong, Wenxiang; Zhang, Wenchuan

    2017-01-01

    Abstract Rationale: Thalamic pain is a distressing and treatment-resistant type of central post-stroke pain. Although stellate ganglion block is an established intervention used in pain management, its use in the treatment of thalamic pain has never been reported. Patient concerns: A 66-year-old woman presented with a 3-year history of severe intermittent lancinating pain on the right side of the face and the right hand. The pain started from the ulnar side of the right forearm after a mild ischemic stroke in bilateral basal ganglia and left thalamus. Weeks later, the pain extended to the dorsum of the finger tips and the whole palmar surface, becoming more severe. Meanwhile, there was also pain with similar characteristics emerging on her right face, resembling atypical trigeminal neuralgia. Diagnoses: Thalamic pain was diagnosed. Interventions: After refusing the further invasive treatment, she was suggested to try stellate ganglion block. Outcomes: After a 3-day period of pain free (numerical rating scale: 0) postoperatively, she reported moderate to good pain relief with a numerical rating scale of about 3 to 4 lasting 1 month after the first injection. Pain as well as the quality of life was markedly improved with less dose of analgesic agents. Lessons: Stellate ganglion block may be an optional treatment for thalamic pain. PMID:28151918

  14. Block Storage Service: Status and Performance

    CERN Document Server

    Van der Ster, Daniel

    2014-01-01

    This memo summarizes the current status of the Ceph block storage service as it is used for OpenStack Cinder Volumes and Glance Images as of May 2014. We present the block storage activity on the current cluster, measuring IOPS and latencies, and present a cost/benefit analysis of using SSDs to optimize the cost and performance efficiency of the service. During tests in collaboration with IT-CF, we have concluded that by adding SSDs as the synchronous write journals (used to guarantee data durability), we are able increase the IOPS capacity by 4-5 times, at a cost of decreasing the available volume by 20%. Further, the testing has shown that the Ceph implementation is able to operate at the limit of the hardware performance; software-induced performance limitations were not yet observed in either the spinning disk or SSD configurations. In addition, we believe that increasing small write performance with SSDs is applicable only to the block storage use-case; high-bandwidth use-cases such as physics data stora...

  15. Active Block Layout: A High Performance Block Layout Mechanism%Active Block Layout:一种高性能磁盘布局机制

    Institute of Scientific and Technical Information of China (English)

    卢军; 卢显良; 罗光春; 韩宏; 魏青松

    2003-01-01

    The access frequency of different files in file system is dissimilar. If file system can optimize the block lay-out of these hot files which are frequently accessed,the performance of file system will be improved. This paper pre-sents a high performance block layout mechanism: Active Block Layout (ABL). ABL can record the access frequencyof every file in file system and actively optimize the block layout of these hot files by block duplicating. The duplicatedblocks can be placed in the special zone of track,which is called "Cooling Zone". ABL can automatically determine theplacing position and the copy count of the blocks which need to be duplicated. In order to reduce the overhead of blockduplication,this paper also presents a mechanism which uses the potential disk bandwidth to realize the block duplica-tion,and does not obviously degrade the performance of file system.

  16. The fusion band in V1: a simple ECG guide to optimal resynchronization? An echocardiographic case report

    Directory of Open Access Journals (Sweden)

    Corbucci Giorgio

    2005-09-01

    Full Text Available Abstract Background Patients with left bundle branch block have a preserved right bundle branch conduction and the efficacy of left ventricular pacing could be explained with the fusion between artificial pulse delivered in the left lateral wall and the spontaneous right ventricular activation. Moreover, the efficacy of left ventricular pacing could be enhanced with an optimal timing between the spontaneous right ventricular activation and the left ventricular pulse. Case presentation We evaluated a patient (male, 47 yrs with surgically corrected mitral regurgitation, sinus rhythm and left bundle branch block, heart failure (NYHA class III despite medical therapy and low ejection fraction (25%: he was implanted with a biventricular device. We programmed ventricular pacing only through the left ventricular lead. We defined what we called electrocardiographic "fusion band" as follow: programming OFF the stimulator, we recorded the native electrocardiogram and measured, through the device, the intrinsic atrioventricular interval. Then, atrioventricular interval was progressively shortened by steps of 20 ms down to 100 ms. Twelve leads electrocardiogram was recorded at each step. The fusion band is the range of AV intervals at which surface electrocardiogram (mainly in V1 lead presents an intermediate morphology between the native left bundle branch block (upper limit of the band and the fully paced right bundle branch block (lower limit. The patient underwent echocardiographic examination at each atrioventricular interval chosen inside the fusion band. The following parameters were evaluated: ejection fraction, diastolic filling time, E wave deceleration time, aortic velocity time integral and myocardial performance index. All the echocardiographic parameters showed an improvement inside the fusion band, with a "plateau" behaviour. As the fusion band in this patient ranged from an atrioventricular delay of 200 ms to an atrioventricular delay of 120

  17. Rapid self-assembly of block copolymers to photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Yan; Sveinbjornsson, Benjamin R; Grubbs, Robert H; Weitekamp, Raymond; Miyake, Garret M; Atwater, Harry A; Piunova, Victoria; Daeffler, Christopher Scot; Hong, Sung Woo; Gu, Weiyin; Russell, Thomas P.

    2016-07-05

    The invention provides a class of copolymers having useful properties, including brush block copolymers, wedge-type block copolymers and hybrid wedge and polymer block copolymers. In an embodiment, for example, block copolymers of the invention incorporate chemically different blocks comprising polymer size chain groups and/or wedge groups that significantly inhibit chain entanglement, thereby enhancing molecular self-assembly processes for generating a range of supramolecular structures, such as periodic nanostructures and microstructures. The present invention also provides useful methods of making and using copolymers, including block copolymers.

  18. A POCS-Based Algorithm for Blocking Artifacts Reduction

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yi-hong; CHENG Guo-hua; YU Song-yu

    2006-01-01

    An algorithm for blocking artifacts reduction in DCT domain for block-based image coding was developed. The algorithm is based on the projection onto convex set (POCS) theory. Due to the fact that the DCT characteristics of shifted blocks are different caused by the blocking artifacts, a novel smoothness constraint set and the corresponding projection operator were proposed to reduce the blocking artifacts by discarding the undesired high frequency coefficients in the shifted DCT blocks. The experimental results show that the proposed algorithm outperforms the conventional algorithms in terms of objective quality, subjective quality, and convergence property.

  19. Development of Deflection Prediction Model for Concrete Block Pavement Considering the Block Shapes and Construction Patterns

    Directory of Open Access Journals (Sweden)

    Wuguang Lin

    2016-01-01

    Full Text Available Concrete block pavement (CBP is distinct from typical concrete or asphalt pavements. It is built by using individual blocks with unique construction patterns forming a discrete surface layer to bear traffic loadings. The surface structure of CBP varies depending on the block shapes and construction patterns, so it is hard to apply a general equivalent elastic modulus estimation method to define the surface structural strength. In this study, FEM analysis and dynamic loading test were carried out to develop a deflection prediction model for CBP considering the block shapes and construction patterns. Based on the analysis results, it was found that block shapes did not have much effect on load distribution, whereas construction patterns did. By applying the deflection prediction model to the rutting model for CBP proposed by Sun, the herringbone bond pattern showed the best performance comparing with stretcher bond or basket weave bond pattern. As the load repetition increased to 1.2 million, the rutting depth of CBP constructed by herringbone bond pattern was 2 mm smaller than those constructed by the other two patterns.

  20. Computing eigenvectors of block tridiagonal matrices based on twisted block factorizations.

    Science.gov (United States)

    König, Gerhard; Moldaschl, Michael; Gansterer, Wilfried N

    2012-09-01

    New methods for computing eigenvectors of symmetric block tridiagonal matrices based on twisted block factorizations are explored. The relation of the block where two twisted factorizations meet to an eigenvector of the block tridiagonal matrix is reviewed. Based on this, several new algorithmic strategies for computing the eigenvector efficiently are motivated and designed. The underlying idea is to determine a good starting vector for an inverse iteration process from the twisted block factorizations such that a good eigenvector approximation can be computed with a single step of inverse iteration. An implementation of the new algorithms is presented and experimental data for runtime behaviour and numerical accuracy based on a wide range of test cases are summarized. Compared with competing state-of-the-art tridiagonalization-based methods, the algorithms proposed here show strong reductions in runtime, especially for very large matrices and/or small bandwidths. The residuals of the computed eigenvectors are in general comparable with state-of-the-art methods. In some cases, especially for strongly clustered eigenvalues, a loss in orthogonality of some eigenvectors is observed. This is not surprising, and future work will focus on investigating ways for improving these cases.

  1. A comparison of four different block bootstrap methods

    Directory of Open Access Journals (Sweden)

    Boris Radovanov

    2014-12-01

    Full Text Available The paper contains a description of four different block bootstrap methods, i.e., non-overlapping block bootstrap, overlapping block bootstrap (moving block bootstrap, stationary block bootstrap and subsampling. Furthermore, the basic goal of this paper is to quantify relative efficiency of each mentioned block bootstrap procedure and then to compare those methods. To achieve the goal, we measure mean square errors of estimation variance returns. The returns are calculated from 1250 daily observations of Serbian stock market index values BELEX15 from April 2009 to April 2014. Thereby, considering the effects of potential changes in decisions according to variations in the sample length and purposes of the use, this paper introduces stability analysis which contains robustness testing of the different sample size and the different block length. Testing results indicate some changes in bootstrap method efficiencies when altering the sample size or the block length.

  2. Outer Continental Shelf Lease Blocks - Atlantic Region NAD83

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains OCS block outlines in ArcGIS shape file format for the BOEM Atlantic Region. OCS blocks are used to define small geographic areas within an...

  3. Lifting of a sector block for YE-2 at Kawasaki.

    CERN Multimedia

    R. Loveless/U. of Wisconsin

    2000-01-01

    YE-2 is build from machined sector blocks. Trial assembly is carried out horizontally. This picture represents the lifting of a machined sector block destined to the trial assembly of a half disk YE-2 at Kawasaki (KHI) Kobe, Japan.

  4. Recurrence relations for toric N=1 superconformal blocks

    CERN Document Server

    Hadasz, Leszek; Suchanek, Paulina

    2012-01-01

    General 1-point toric blocks in all sectors of N=1 superconformal field theories are analyzed. The recurrence relations for blocks coefficients are derived by calculating their residues and large $\\Delta$ asymptotics.

  5. Outer Continental Shelf Lease Blocks - Alaska Region NAD83

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains Outer Continental Shelf block outlines in ArcGIS shapefile format for the BOEM Alaska Region. OCS blocks are used to define small geographic...

  6. Novel Efficient De-blocking Method for Highly Compressed Images

    Institute of Scientific and Technical Information of China (English)

    SHI Min; YI Qing-ming; YANG Liang

    2007-01-01

    Due to coarse quantization,block-based discrete cosine transform(BDCT) compression methods usually suffer from visible blocking artifacts at the block boundaries.A novel efficient de-blocking method in DCT domain is proposed.A specific criterion for edge detection is given,one-dimensional DCT is applied on each row of the adjacent blocks and the shifted block in smooth region,and the transform coefficients of the shifted block are modified by weighting the average of three coefficients of the block.Mean square difference of slope criterion is used to judge the efficiency of the proposed algorithm.Simulation results show that the new method not only obtains satisfactory image quality,but also maintains high frequency information.

  7. Block copolymer/ferroelectric nanoparticle nanocomposites

    Science.gov (United States)

    Pang, Xinchang; He, Yanjie; Jiang, Beibei; Iocozzia, James; Zhao, Lei; Guo, Hanzheng; Liu, Jin; Akinc, Mufit; Bowler, Nicola; Tan, Xiaoli; Lin, Zhiqun

    2013-08-01

    Nanocomposites composed of diblock copolymer/ferroelectric nanoparticles were formed by selectively constraining ferroelectric nanoparticles (NPs) within diblock copolymer nanodomains via judicious surface modification of ferroelectric NPs. Ferroelectric barium titanate (BaTiO3) NPs with different sizes that are permanently capped with polystyrene chains (i.e., PS-functionalized BaTiO3NPs) were first synthesized by exploiting amphiphilic unimolecular star-like poly(acrylic acid)-block-polystyrene (PAA-b-PS) diblock copolymers as nanoreactors. Subsequently, PS-functionalized BaTiO3 NPs were preferentially sequestered within PS nanocylinders in the linear cylinder-forming polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) diblock copolymer upon mixing the BaTiO3 NPs with PS-b-PMMA. The use of PS-b-PMMA diblock copolymers, rather than traditional homopolymers, offers the opportunity for controlling the spatial organization of PS-functionalized BaTiO3 NPs in the PS-b-PMMA/BaTiO3 NP nanocomposites. Selective solvent vapor annealing was utilized to control the nanodomain orientation in the nanocomposites. Vertically oriented PS nanocylinders containing PS-functionalized BaTiO3 NPs were yielded after exposing the PS-b-PMMA/BaTiO3 NP nanocomposite thin film to acetone vapor, which is a selective solvent for PMMA block. The dielectric properties of nanocomposites in the microwave frequency range were investigated. The molecular weight of PS-b-PMMA and the size of BaTiO3 NPs were found to exert an apparent influence on the dielectric properties of the resulting nanocomposites.Nanocomposites composed of diblock copolymer/ferroelectric nanoparticles were formed by selectively constraining ferroelectric nanoparticles (NPs) within diblock copolymer nanodomains via judicious surface modification of ferroelectric NPs. Ferroelectric barium titanate (BaTiO3) NPs with different sizes that are permanently capped with polystyrene chains (i.e., PS-functionalized BaTiO3NPs) were

  8. Interactive Poster: Exploring Block Access Patterns of Native XML Storage

    OpenAIRE

    Janetzko, Halldór; Keim, Daniel A.; Kramis, Marc; Mansmann, Florian; Waldvogel, Marcel

    2006-01-01

    Recent block-based native XML storage systems such as IDEFIX touch blocks according to the XQuery engine s execution plan. The resulting access patterns are virtually unknown and potentially cause many expensive disk seeks. Visualization comes to the rescue when extensive log files must be analyzed a tedious and difficult task. The dynamic time-based block-touch animation as well as the static block-type information of VISUAL IDEFIX foster the insight into the performance-critical internals...

  9. Hardware realization of chaos based block cipher for image encryption

    KAUST Repository

    Barakat, Mohamed L.

    2011-12-01

    Unlike stream ciphers, block ciphers are very essential for parallel processing applications. In this paper, the first hardware realization of chaotic-based block cipher is proposed for image encryption applications. The proposed system is tested for known cryptanalysis attacks and for different block sizes. When implemented on Virtex-IV, system performance showed high throughput and utilized small area. Passing successfully in all tests, our system proved to be secure with all block sizes. © 2011 IEEE.

  10. PERIPHERAL BLOCK ANESTHESIA OF UPPER EXTREMITY AND ITS COMPLICATIONS

    OpenAIRE

    Tapar, Hakan; SÜREN, Mustafa; Kaya, Ziya; Arıcı, Semih; Karaman, Serkan; Kahveci, Mürsel

    2012-01-01

    Successful peripheral blocks and selection of appropriate technique according to surgery is possible with a good knowledge of anatomy. Regional peripheral block anesthesia of upper extremity which applied by single injection to plexus brachialis is the most recommended method of anesthesia in daily surgical procedures. The most important advantages of peripheral nerve blocks which are type of regional anesthesia according to general anesthesia and central blocks are less effect to...

  11. The Moore-Penrose Inverse of Block Magic Rectangles

    Science.gov (United States)

    Hakopian, Y. R.; Eloyan, A. N.

    2007-01-01

    As is known, a semi-magic square is an "n x n" matrix having the sum of entries in each row and each column equal to a constant. This note generalizes this notion and introduce a special class of block matrices called "block magic rectangles." It is proved that the Moore-Penrose inverse of a block magic rectangle is also a block magic rectangle.

  12. Brucella Infection Associated with Complete Atrioventricular Block

    Science.gov (United States)

    Bilici, Meki; Demir, Fikri; Yılmazer, Murat Muhtar; Bozkurt, Fatma; Tuzcu, Volkan

    2016-01-01

    Background: The clinical spectrum of Brucella infection is quite diverse and characterized by multi-system involvement. Patients present with myocarditis, endocarditis, or pericarditis. Infective endocarditis is the most common cardiovascular complication in patients with brucellosis. Although conduction abnormalities are seen in cases with endocarditis, they are reported very rarely in the setting of cardiac Brucella infection. Case Report: An eight and a half-year-old male patient was referred to our clinic due to inadequate response to cotrimaxazole plus streptomycin treatment at the 15th day of admission. Although local hospital records on the patient showed a heart rate of 80 bpm, we determined a heart rate of 46 bpm. The electrocardiogram showed complete atrioventricular (AV) block. The average heart rate was determined as 48 bpm with 24-hour Holter electrocardiogram (ECG) monitoring. The echocardiographic examination showed normal-sized heart chambers and the absence of valvular involvement. An agglutination test for brucellosis was found to be positive with a titer of 1/320. High fever, arthralgia, and splenomegaly regressed following doxycycline plus rifampicin therapy, but there was no improvement in the AV block. A permanent pacemaker was implanted because of the detection of an average heart rate of 48 bpm. Conclusion: Because cardiac failure and rhythm abnormalities are reported in the course of Brucella infection and may be associated with significant outcomes, cases with brucellosis should be evaluated carefully in terms of cardiac involvement. This report aims to draw attention to complete AV block as an extremely rare complication of Brucella infection. PMID:27761286

  13. Intermittent Atrioventricular Block following Fingolimod Initiation

    Directory of Open Access Journals (Sweden)

    E. Gialafos

    2014-01-01

    Full Text Available A 47-year-old female patient with multiple sclerosis (MS developed symptomatic intermittent 2nd degree atrioventricular block (AVB of five-hour duration, five hours after the first two doses of fingolimod, that resolved completely. Frequency domain analysis of heart rate variability (HRV revealed increased parasympathetic activity and decreased sympathetic tone, while modified Ewing tests were suggestive of impaired cardiac sympathetic function. We hypothesize that expression of this particular arrhythmia might be related to autonomic nervous system (ANS dysfunction due to demyelinating lesions in the upper thoracic spinal cord, possibly augmented by the parasympathetic effect of the drug.

  14. House moves to block Internet censorship.

    Science.gov (United States)

    Mirken, B

    1995-08-18

    Congress has created conflicting amendments to the Communications Decency Act, an amendment to the telecommunications deregulation bill. The Senate amendment contains sweeping language barring objectionable communications online. Observers fear this will block online distribution of AIDS prevention information as well as bar responses by activist's of drug companies and government officials. The House amendments seek to protect online services from liability if they restrict access to objectionable materials, while another amendment seeks to modify obscenity laws to criminalize only some forms of online speech. These conflicts are to be resolved in a House-Senate conference committee whose meeting date is yet to be decided.

  15. Germanium Blocked Impurity Band (BIB) detectors

    Science.gov (United States)

    Haller, E. E.; Baumann, H.; Beeman, J. W.; Hansen, W. L.; Luke, P. N.; Lutz, M.; Rossington, C. S.; Wu, I. C.

    1989-01-01

    Information is given in viewgraph form. The advantages of the Si blocked impurity band (BIB) detector invented by M. D. Petroff and M. G. Stabelbroek are noted: smaller detection volume leading to a reduction of cosmic ray interference, extended wavelength response because of dopant wavefunction overlap, and photoconductive gain of unity. It is argued that the stated advantages of Si BIB detectors should be realizable for Ge BIB detectors. Information is given on detector development, subtrate choice and preparation, wafer polising, epitaxy, characterization of epi layers, and preliminary Ge BIB detector test results.

  16. Building blocks for correlated superconductors and magnets

    Directory of Open Access Journals (Sweden)

    J. L. Sarrao

    2015-04-01

    Full Text Available Recent efforts at Los Alamos to discover strongly correlated superconductors and hard ferromagnets are reviewed. While serendipity remains a principal engine of materials discovery, design principles and structural building blocks are beginning to emerge that hold potential for predictive discovery. Successes over the last decade with the so-called “115” strongly correlated superconductors are summarized, and more recent efforts to translate these insights and principles to novel hard magnets are discussed. While true “materials by design” remains a distant aspiration, progress is being made in coupling empirical design principles to electronic structure simulation to accelerate and guide materials design and synthesis.

  17. Building blocks for correlated superconductors and magnets

    Energy Technology Data Exchange (ETDEWEB)

    Sarrao, J. L.; Ronning, F.; Bauer, E. D.; Batista, C. D.; Zhu, J.-X.; Thompson, J. D. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2015-04-01

    Recent efforts at Los Alamos to discover strongly correlated superconductors and hard ferromagnets are reviewed. While serendipity remains a principal engine of materials discovery, design principles and structural building blocks are beginning to emerge that hold potential for predictive discovery. Successes over the last decade with the so-called “115” strongly correlated superconductors are summarized, and more recent efforts to translate these insights and principles to novel hard magnets are discussed. While true “materials by design” remains a distant aspiration, progress is being made in coupling empirical design principles to electronic structure simulation to accelerate and guide materials design and synthesis.

  18. Subsea building blocks for slender wells

    Energy Technology Data Exchange (ETDEWEB)

    Sabedotti, Sergio

    2010-07-01

    Reduce the Life Cycle Cost (LCC), IOR and improve HSE are fundamental aspects in future subsea field developments. The SBB (Subsea Building Blocks) is an R D effort from Statoil and Aker Solutions to investigate and develop new technology that can allow the industry to achieve these objectives. One important aspect of this initiative is well construction and reduced rig time for drilling, completion and intervention of subsea wells. To enable a slender system and increase the operational flexibility, well equipment (WH, XMT) has been analyzed and redesigned. (Author)

  19. Some results on resolvable incomplete block designs

    Institute of Scientific and Technical Information of China (English)

    LIU; Minqian; FANG; Kaitai

    2005-01-01

    This paper is concerned with the uniformity of a certain kind of resolvable incomplete block (RIB for simplicity) design which is called the PRIB design here. A sufficient and necessary condition is obtained, under which a PRIB design is the most uniform in the sense of a discrete discrepancy measure, and the uniform PRIB design is shown to be connected. A construction method for such designs via a kind of U-type designs is proposed, and an existence result of these designs is given. This method sets up an important bridge between PRIB designs and U-type designs.

  20. Heart block following topical latanoprost treatment

    Science.gov (United States)

    De Smit, Elisabeth; Theodorou, Maria; Hildebrand, Göran Darius; Bloom, Philip

    2011-01-01

    The authors report a case of second degree heart block associated with topical latanoprost treatment. The authors discuss the possibility of a causative effect as the cessation of this treatment resulted in improvement of the arrhythmia. The authors highlight previous reports and research in humans and animals which demonstrate an association of arrhythmias with prostaglandin analogues. This report draws attention to the possibility that an extremely commonly prescribed topical drug may trigger arrhythmias in susceptible individuals. It is important that prescribers are aware of this possible side-effect. PMID:22679164

  1. Birth of a nanoscience building block.

    Science.gov (United States)

    Alivisatos, A Paul

    2008-08-01

    The first Kavli Prize in Nanoscience has recognized two giants of the field, Louis Brus and Sumio Ijima, who have helped to lay the foundation of the field of nanoscience through their efforts to develop two of the most fundamental nanoscience building blocks: colloidal quantum dots and the carbon nanotube. In this Focus, I provide a brief history on the birth of the field of semiconductor nanoparticles, or quantum dots, and outline the contributions that Louis Brus has made in this area, which have served to advance the field of nanoscience in vast and far-reaching ways.

  2. Pudendal nerve block for vaginal birth.

    Science.gov (United States)

    Anderson, Deborah

    2014-01-01

    Pudendal nerve block is a safe and effective pain relief method for vaginal birth. Providing analgesia to the vulva and anus, it is used for operative vaginal birth and subsequent repair, late second stage pain relief with spontaneous vaginal birth, repair of complex lacerations, or repair of lacerations in women who are unable to achieve adequate or satisfactory pain relief during perineal repair with local anesthesia. Key to its efficacy is the knowledge of pudendal nerve anatomy, the optimal point of infiltration of local anesthetic, and an understanding of the amount of time necessary to effect adequate analgesia.

  3. 21 CFR 520.905e - Fenbendazole blocks.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Fenbendazole blocks. 520.905e Section 520.905e... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.905e Fenbendazole blocks. (a) Specifications. (1) Each pound of molasses block contains 750 milligrams of fenbendazole. (2) Each pound...

  4. From Block Copolymers to Nano-porous Materials

    DEFF Research Database (Denmark)

    Vigild, Martin Etchells; Ndoni, Sokol; Berg, Rolf Henrik

    2003-01-01

    Quantitative etching of the polydimethylsiloxane block in a series of polystyrene-polydimethylsiloxane (PS-PDMS) block copolymers is reported. Reacting the block copolymer with anhydrous hydrogen fluoride (HF) renders a nanoporous material with the remaining PS maintaining the original morphology...

  5. Electrical Structure of the Crus Beneath the Ordos Block

    Institute of Scientific and Technical Information of China (English)

    Zhao Guoze; Zhan Yan; Wang Lifeng; Wang Jijun; Tang Ji; Chen Xiaobin; Xiao Qibin

    2011-01-01

    The Ordos block is a stable tectonic unit since the Cenozoic. Whether low-resistivity layers exist in the middle and lower crust of this kind block is an open question. This work attempts to reveal the entire crustal structure of the block based on interp

  6. 45 CFR 96.112 - Community services block grant.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Community services block grant. 96.112 Section 96... Transition Provisions § 96.112 Community services block grant. (a) For the fiscal year beginning October 1, 1981, only, a State may choose to operate programs under the community services block grant or,...

  7. Equity Block Transfers in Transition Economies : Evidence from Poland

    NARCIS (Netherlands)

    Trojanowski, G.

    2002-01-01

    This Paper investigates valuation effects of share block transfers and employs agency theory to explain the determinants of block premia. A sample of transactions from Poland is used to measure benefits and costs of ownership concentration. Block premia are found to be substantially lower than in we

  8. 14 CFR 33.57 - General conduct of block tests.

    Science.gov (United States)

    2010-01-01

    ... Section 33.57 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.57 General conduct of block tests. (a) The applicant may, in conducting the block tests, use separate engines of...

  9. 14 CFR 33.99 - General conduct of block tests.

    Science.gov (United States)

    2010-01-01

    ... Section 33.99 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.99 General conduct of block tests. (a) Each applicant may, in making a block test, use separate engines of identical design...

  10. Application of multi-block methods in cement production

    DEFF Research Database (Denmark)

    Svinning, K.; Høskuldsson, Agnar

    2008-01-01

    Compressive strength at 1 day of Portland cement as a function of the microstructure of cement was statistically modelled by application of multi-block regression method. The observation X-matrix was partitioned into four blocks, the first block representing the mineralogy, the second particle size...

  11. BLOCK BIDIAGONALIZATION METHODS FOR MULTIPLE NONSYMMETRIC LINEAR SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    戴华

    2001-01-01

    The symmetric linear system gives us many simplifications and a possibility to adapt the computations to the computer at hand in order to achieve better performance. The aim of this paper is to consider the block bidiagonalization methods derived from a symmetric augmented multiple linear systems and make a comparison with the block GMRES and block biconjugate gradient methods.

  12. Differential Reinforcement with and without Blocking as Treatment for Elopement

    Science.gov (United States)

    Call, Nathan A.; Pabico, Ryan S.; Findley, Addie J.; Valentino, Amber L.

    2011-01-01

    Blocking is a frequent component of treatments for elopement. Unfortunately, blocking may not always be feasible because elopement often occurs when supervision is low or the behavior cannot be prevented. The present study evaluated the use of blocking in the treatment of elopement by using differential reinforcement of other behavior with and…

  13. Block Preconditioners for Complex Symmetric Linear System with Two-by-Two Block Form

    Directory of Open Access Journals (Sweden)

    Shi-Liang Wu

    2015-01-01

    Full Text Available Based on the previous work by Zhang and Zheng (A parameterized splitting iteration method for complex symmetric linear systems, Japan J. Indust. Appl. Math., 31 (2014 265–278, three block preconditioners for complex symmetric linear system with two-by-two block form are presented. Spectral properties of the preconditioned matrices are discussed in detail. It is shown that all the eigenvalues of the preconditioned matrices are well-clustered. Numerical experiments are reported to illustrate the efficiency of the proposed preconditioners.

  14. Controlling Structure in Sulfonated Block Copolymer Membranes

    Science.gov (United States)

    Truong, Phuc; Stein, Gila; Strzalka, Joe

    2015-03-01

    In many ionic block copolymer systems, the strong incompatibility between ionic and non-ionic segments will trap non-equilibrium structures in the film, making it difficult to engineer the optimal domain sizes and transport pathways. The goal of this work is to establish a framework for controlling the solid-state structure of sulfonated pentablock copolymer membranes. They have ABCBA block sequence, where A is poly(t-butyl styrene), B is poly(hydrogenated isoprene), and C is poly(styrene sulfonate). To process into films, the polymer is dissolved in toluene/n-propanol solvent mixtures, where the solvent proportions and the polymer loading were both varied. Solution-state structure was measured with small angle X-ray scattering (SAXS). We detected micelles with radii that depend on the solvent composition and polymer loading. Film structure was measured with grazing-incidence SAXS, which shows (i) domain periodicity is constant throughout film thickness; (ii) domain periodicity depends on solvent composition and polymer loading, and approximately matches the micelle radii in solutions. The solid-state packing is consistent with a hard sphere structure factor. Results suggest that solid-state structure can be tuned by manipulating the solution-state self-assembly.

  15. Blocking-resistant communication through domain fronting

    Directory of Open Access Journals (Sweden)

    Fifield David

    2015-06-01

    Full Text Available We describe “domain fronting,” a versatile censorship circumvention technique that hides the remote endpoint of a communication. Domain fronting works at the application layer, using HTTPS, to communicate with a forbidden host while appearing to communicate with some other host, permitted by the censor. The key idea is the use of different domain names at different layers of communication. One domain appears on the “outside” of an HTTPS request—in the DNS request and TLS Server Name Indication—while another domain appears on the “inside”—in the HTTP Host header, invisible to the censor under HTTPS encryption. A censor, unable to distinguish fronted and nonfronted traffic to a domain, must choose between allowing circumvention traffic and blocking the domain entirely, which results in expensive collateral damage. Domain fronting is easy to deploy and use and does not require special cooperation by network intermediaries. We identify a number of hard-to-block web services, such as content delivery networks, that support domain-fronted connections and are useful for censorship circumvention. Domain fronting, in various forms, is now a circumvention workhorse. We describe several months of deployment experience in the Tor, Lantern, and Psiphon circumvention systems, whose domain-fronting transports now connect thousands of users daily and transfer many terabytes per month.

  16. Block Models and Personalized PageRank

    CERN Document Server

    Kloumann, Isabel; Kleinberg, Jon

    2016-01-01

    Methods for ranking the importance of nodes in a network have a rich history in machine learning and across domains that analyze structured data. Recent work has evaluated these methods though the seed set expansion problem: given a subset $S$ of nodes from a community of interest in an underlying graph, can we reliably identify the rest of the community? We start from the observation that the most widely used techniques for this problem, personalized PageRank and heat kernel methods, operate in the space of landing probabilities of a random walk rooted at the seed set, ranking nodes according to weighted sums of landing probabilities of different length walks. Both schemes, however, lack an a priori relationship to the seed set objective. In this work we develop a principled framework for evaluating ranking methods by studying seed set expansion applied to the stochastic block model. We derive the optimal gradient for separating the landing probabilities of two classes in a stochastic block model, and find, ...

  17. [Acute atrioventricular block in chronic Lyme disease].

    Science.gov (United States)

    Wagner, Vince; Zima, Endre; Gellér, László; Merkely, Béla

    2010-09-26

    The tick bite transmitted Lyme disease is one of the most common antropozoonosis, about 10 000 new infections are reported in Hungary each year. The progress and clinical presentation can vary, and carditis can occur in later stages. A serologically verified Lyme disease caused third degree atrioventricular block in young male presenting with presyncope. Based on the tick-bites mentioned a few weeks prior to hospital admission, Lyme carditis was considered with the administration of antibiotics and monitor observation. Typical skin lesions were not recognized and laboratory findings showed no pathology. An electrophysiological study recorded a predominant supra-His atrioventricular block. Total regression of conduction could be detected later and the serological tests established an underlying Lyme disease. Currently no definite treatment recommendation is available for the potentially reversible Lyme carditis. The tick bite seemed to be the key on our way to diagnosis; however, serological tests proved the disease to be older than one year. A detailed medical history and serological tests are essential in identifying the cause and pacemaker implantation can be avoided.

  18. Block-based quantum-logic synthesis

    CERN Document Server

    Saeedi, Mehdi; Zamani, Morteza Saheb; Sedighi, Mehdi

    2010-01-01

    In this paper, the problem of constructing an efficient quantum circuit for the implementation of an arbitrary quantum computation is addressed. To this end, a basic block based on the cosine-sine decomposition method is suggested which contains $l$ qubits. In addition, a previously proposed quantum-logic synthesis method based on quantum Shannon decomposition is recursively applied to reach unitary gates over $l$ qubits. Then, the basic block is used and some optimizations are applied to remove redundant gates. It is shown that the exact value of $l$ affects the number of one-qubit and CNOT gates in the proposed method. In comparison to the previous synthesis methods, the value of $l$ is examined consequently to improve either the number of CNOT gates or the total number of gates. The proposed approach is further analyzed by considering the nearest neighbor limitation. According to our evaluation, the number of CNOT gates is increased by at most a factor of $\\frac{5}{3}$ if the nearest neighbor interaction i...

  19. TRUE Block Scale Continuation Project. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Peter; Byegaard, Johan [Geosigma AB (Sweden); Billaux, Daniel [Itasca Consultants SA (France); Cvetkovic, Vladimir [Royal Inst. of Technology, Stockholm (Sweden); Dershowitz, William; Doe, Thomas [Golder Associates Inc. (United States); Hermanson, Jan [Golder Associates AB (Sweden); Poteri, Antti [VTT (Finland); Tullborg, Eva-Lena [Terralogica AB (Sweden); Winberg, Anders [Conterra AB (SE)] (ed.)

    2007-03-15

    The TRUE Block Scale project was carried out during 1996-2002. This project focused on site characterisation and building of hydrostructural and microstructural models, sorbing tracer experiments in single structures and networks of structures over distances ranging between 1 and 100 m and also involved a unified application of various model approaches for modelling the in situ experiments. In 2002, ANDRA, Posiva, JNC and SKB decided to pursue some remaining issues in the so-called TRUE Block Scale Continuation project (TRUE BS2). The specific objectives of BS2 can be summarised as: 'Improve understanding of transport pathways at the block scale, including assessment of effects of geology and geometry, macrostructure and microstructure'. In order to cater to addressing the stated objective a series of hypotheses were formulated which explored the importance of geological information for predicting transport and retention and the possible differences between transport and retention between transport paths dominated by faults and those dominated by non-fault fractures (background fractures). In the process, prospects for carrying out experiments in fracture networks over longer distances (c 20-100 m) were explored. It was identified that experiments with sorbing tracers over these distances were prohibitive because of the time frames involved and the projected low mass recoveries. Instead the experimental locus was shifted to a geological structure previously not investigated by tracer tests in the TRUE Block Scale experiments. The lower immobile zone retention material properties assigned to background fractures compared to those assigned to the fault-type Structure 19 have been verified by means of back-calculations. The evaluated Type 1 flow path (Structure 19, Flow path I) retention material properties, as expressed by {kappa} parameter, are one order of magnitude higher than for the background fracture flow path. This finding is consistent with the

  20. Compatibilization of low-density polyethylene/polystyrene blends by segmented EB(PS-block-EB)(n) block copolymers

    NARCIS (Netherlands)

    Kroeze, E; ten Brinke, G.; Hadziioannou, G

    1997-01-01

    Hydrogenated segmented poly[butadiene-block-(styrene-block-butadiene)(n)] block copolymers, which were developed by use of a polymeric iniferter technique, were tested on their compatibilizing effectiveness for (10/90) LDPE/PS blends. They were found to be effective compatibilizers for this mixture,

  1. Heat Transfer Enhancement in Turbulent Flows by Blocked Surfaces

    Directory of Open Access Journals (Sweden)

    Onur YEMENİCİ

    2013-04-01

    Full Text Available In this study, the heat transfer analyses over flat and blocked surfaces were carried out in turbulent flow under the influence of the block height. A constant-temperature hot wire anemometer was used to the velocity and turbulent intensity measurements, while temperature values were measured by copper-constantan thermocouples. The average Stanton numbers for block heights of 15 and 25 mm were higher than those of flat surface by %38 and %84, respectively. The results showed that the presence of the blocks increased the heat transfer and the enhancement rose with block heights

  2. INVERSE DDA OF A SYSTEM OF BLOCKS IN SPHERE COORDINATES

    Institute of Scientific and Technical Information of China (English)

    WuYun; WangHui; ZhouShuoyu; ShiShunying

    2003-01-01

    In accordance with the geometric equations of elastic-mechanics in the sphere-coordinates, the displacement equation of blocks on asphere consisting of 6 deforming parameters is developed. The formula for distance between blocks is derived under the supposition that all block boundaries are prime arcs. The kinematic constraint and the penalty function for reasonable contact between blocks are developed. The normal equations and their coefficient matrix, based on the Least Squares Principle, are derived. The problem of adjudging penetration between blocks is discussed, and a solution is proposed.

  3. Grayscale Image Compression Based on Min Max Block Truncating Coding

    Directory of Open Access Journals (Sweden)

    Hilal Almarabeh

    2011-11-01

    Full Text Available This paper presents an image compression techniques based on block truncating coding. In this work, a min max block truncating coding (MM_BTC is presented for grayscale image compression relies on applying dividing image into non-overlapping blocks. MM_BTC differ from other block truncating coding such as block truncating coding (BTC in the way of selecting the quantization level in order to remove redundancy. Objectives measures such as: Bit Rate (BR, Mean Square Error (MSE, Peak Signal to Noise Ratio (PSNR, and Redundancy (R, were used to present a detailed evaluation of MM_BTC of image quality.

  4. Development of chronic heart failure in a young woman with hypertension associated with renal artery stenosis with preserved renal function

    DEFF Research Database (Denmark)

    Byrne, Christina; Abdulla, Jawdat

    2014-01-01

    A 33-year-old woman with presumed essential hypertension and symptoms equivalent to New York Heart Association class II was suspected of heart failure and referred to echocardiography. The patient's ECG showed a left bundle branch block. Electrolytes, serum creatinine and estimated-glomerular fil......A 33-year-old woman with presumed essential hypertension and symptoms equivalent to New York Heart Association class II was suspected of heart failure and referred to echocardiography. The patient's ECG showed a left bundle branch block. Electrolytes, serum creatinine and estimated......-glomerular filtration rate as well as urine test for protein were all normal. The patient had no peripheral oedema. The transthoracic echocardiography confirmed systolic and diastolic dysfunction and an ejection fraction of 25% and left ventricular hypertrophy. Ultrasound of renal arteries and renal CT angiography...... (renal CTA) revealed a significant stenosis and an aneurysm corresponding to the right renal artery with challenges to traditional interventions....

  5. New Blocking Artifacts Reduction Method Based on Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    SHI Min; YI Qing-ming

    2007-01-01

    It is well known that a block discrete cosine transform compressed image exhibits visually annoying blocking artifacts at low-bit-rate. A new post-processing deblocking algorithm in wavelet domain is proposed. The algorithm exploits blocking-artifact features shown in wavelet domain. The energy of blocking artifacts is concentrated into some lines to form annoying visual effects after wavelet transform. The aim of reducing blocking artifacts is to capture excessive energy on the block boundary effectively and reduce it below the visual scope. Adaptive operators for different subbands are computed based on the wavelet coefficients. The operators are made adaptive to different images and characteristics of blocking artifacts. Experimental results show that the proposed method can significantly improve the visual quality and also increase the peak signal-noise-ratio(PSNR) in the output image.

  6. Structure of Block Copolymer Hydrogel Formed by Complex Coacervate Process

    Science.gov (United States)

    Choi, Soohyung; Ortony, Julia; Krogstad, Daniel; Spruell, Jason; Lynd, Nathaniel; Han, Songi; Kramer, Edward

    2012-02-01

    Complex coacervation occurs when oppositely charged polyelectrolytes associate in solution, forming dense micron-sized droplets. Hydrogels with coacervate block domains were formed by mixing two ABA and A'BA' triblock copolymer solutions in water where the A and A' blocks are oppositely charged. Small-angle neutron scattering (SANS) was used to investigate the structure of hydrogels formed by ABA triblock copolymers (A block: poly(allyl glycidyl ether) functionalized with guanidinium (A) or sulfonate (A'), B block: poly(ethylene oxide)). By using an appropriate fitting model, structural information such as coacervate core block radius and water volume fraction w can be extracted from SANS data. The results reveal that w in the coacervate core block was significantly higher than in conventional triblock copolymer hydrogels where microphase separation is driven by the hydrophobicity of the core-forming blocks.

  7. Does obturator nerve block always occur in 3-1 block?

    Directory of Open Access Journals (Sweden)

    İbrahim Tekdemir

    2011-06-01

    Full Text Available In the femoral “3-in-1 block”, obturator nerve block is routinely unsuccessful. Anatomical studies are not available to explain why blockade of obturator nerve or lumbar plexus does not occur. The aim of this study was to examine the effectiveness of femoral “3-in-1 block” obturator nerve block on a cadaver model.Materials and methods: Totally, 12 mature adult human cadavers were selected. Methylene blue dye (30 ml was injected under the fascia iliaca in eight cadavers and into the femoral nerve sheath in four cadavers. Careful bilateral dissections were performed following dye injections.Results: It was seen that the dye did not spread to the medial part of the psoas major muscle and the obturator nerve was not stained with the dye in eight cadavers in whom dye was injected laterally into the femoral sheat. In four cadavers in whom dye was injected into the femoral nerve sheat, metylene blue spread through fascial layers in the plane under the psoas muscle and stained the obturator nerve just before emerging medially from the fascia psoas. At this point, the obturator nerve pierced the psoas fascia and extended extrafascially in the medial and deep borders of the psoas muscle. In this area, the upper section of the obturator nerve was found also to be stained with the dye.Conclusion: We concluded that the cause of an unsuccessful obturator nerve block might be the fascial anatomy of this region. The lateral cutaneous femoral nerve and the femoral nerve easily can be blocked in the fascia iliaca compartment, but the obturator nerve block fails because of its being extrafascial in this region. J Clin Exp Invest 2011;2(2:149-51

  8. Alkoxyallenes as building blocks for organic synthesis.

    Science.gov (United States)

    Zimmer, Reinhold; Reissig, Hans-Ulrich

    2014-05-01

    Alkoxyallenes are unusually versatile C3 building blocks in organic synthesis. Hence this tutorial review summarizes the most important transformations, including subsequent reactions and their applications in the synthesis of relevant compounds, e.g. natural products. The reactivity patterns involved and the synthons derived from alkoxyallenes are presented. Often alkoxyallenes can serve as substitutes of acrolein or acrolein acetals, utilisation of which has already led to interesting products. Most important is the use of lithiated alkoxyallenes which smoothly react with a variety of electrophiles and lead to products with unique substitution patterns. The heterocycles or carbocycles formed are intermediates for the stereoselective synthesis of natural products or for the preparation of other structurally relevant compounds. The different synthons being put into practice by the use of lithiated alkoxyallenes in these variations will be discussed.

  9. Fibrinogen adsorption on blocked surface of albumin

    DEFF Research Database (Denmark)

    Holmberg, Maria; Hou, Xiaolin

    2011-01-01

    We have investigated the adsorption of albumin and fibrinogen onto PET (polyethylene terephthalate) and glass surfaces and how pre-adsorption of albumin onto these surfaces can affect the adsorption of later added fibrinogen. For materials and devices being exposed to blood, adsorption...... of fibrinogen is often a non-wanted event, since fibrinogen is part of the clotting cascade and unspecific adsorption of fibrinogen can have an influence on the activation of platelets. Albumin is often used as blocking agent for avoiding unspecific protein adsorption onto surfaces in devices designed to handle...... energies, the adsorption of both albumin and fibrinogen has been monitored simultaneously on the same sample. Information about topography and coverage of adsorbed protein layers has been obtained using AFM (Atomic Force Microscopy) analysis in liquid. Our studies show that albumin adsorbs in a multilayer...

  10. Multi-Dimensional Systematic Block Codes

    Institute of Scientific and Technical Information of China (English)

    YUEDianwu; CHENTao

    2004-01-01

    This paper is concerned with a family of Mmulti-dimensional systematic block (MDSB) codes,which can be decoded iteratively. Simulation results of MDSB codes based on Single-parity-check (SPC) and Hamming codes are presented for an additive white Gaussian noise channel. It is shown that performance improves and the code rate decreases with the increasing dimension-ality. Convergence characteristics of iterative decoding are described in detail. Simulation results show that these systematic codes perform better than 2-dimensional counterparts, but have a disadvantage of error floor although they can provide near Shannon capacity's limit performance.MDSB codes offer a good performance versus complexity tradeoff if they use mixture of SPC and Hamming codes as their component codes.

  11. A block orthogonalization procedure with constant synchronizationrequirements

    Energy Technology Data Exchange (ETDEWEB)

    Stathopoulos, Andreas; Wu, Kesheng

    2000-04-17

    We propose an alternative orthonormalization method that computes the orthonormal basis from the right singular vectors of a matrix. Its advantage are: (a) all operations are matrix-matrix multiplications and thus cache-efficient, (b) only one synchronization point is required in parallel implementations, (c) could be more stable than Gram-Schmidt. In addition, we consider the problem of incremental orthonormalization where a block of vectors is orthonormalized against a previously orthonormal set of vectors and among itself. We solve this problem by alternating iteratively between a phase of Gram-Schmidt and a phase of the new method. We provide error analysis and use it to derive bounds on how accurately the two successive orthonormalization phases should be performed to minimize total work performed. Our experiments confirm the favorable numerical behavior of the new method and its effectiveness on modern parallel computers.

  12. Functional Nanoporous Polymers from Block Copolymer Precursors

    DEFF Research Database (Denmark)

    Guo, Fengxiao

    functionalities remains a great challenge due to the limitation of available polymer synthesis and the nanoscale confinement of the porous cavities. The main topic of this thesis is to develop methods for fabrication of functional nanoporous polymers from block copolymer precursors. A method has been developed...... functional nanoporous polymers based on nanoporous 1,2- polybuatdiene 1,2-PB, which is derived from a 1,2-PB-b-PDMS diblock copolymer precursor. As a result, nanoporous 1,2-PB with pores decorated of polyacrylates, sulfonated polymers and poly(ethylene glycol) are created. A method of vapor phase deposition...... has also been generated to obtain nanoporous polymers with functional coatings on pore walls. Vapor phase polymerization of pyrrole is performed to incorporate an ultra thin film of polypyrrole into nanoporous 1,2-PB. The preliminary test shows that nanoporous 1,2-PB gains conductivity. Generally...

  13. Blocks of finite groups and their invariants

    CERN Document Server

    Sambale, Benjamin

    2014-01-01

    Providing a nearly complete selection of up-to-date methods and results on block invariants with respect to their defect groups, this book covers the classical theory pioneered by Brauer, the modern theory of fusion systems introduced by Puig, the geometry of numbers developed by Minkowski, the classification of finite simple groups, and various computer assisted methods. In a powerful combination, these tools are applied to solve many special cases of famous open conjectures in the representation theory of finite groups. Most of the material is drawn from peer-reviewed journal articles, but there are also new previously unpublished results. In order to make the text self-contained, detailed proofs are given whenever possible. Several tables add to the text's usefulness as a reference. The book is aimed at experts in group theory or representation theory who may wish to make use of the presented ideas in their research.

  14. Ulnar conduction block at the wrist.

    Science.gov (United States)

    Seror, P

    1999-10-01

    Two cases of ulnar nerve lesions at the wrist are reported. The lesions had an acute onset and exclusively impaired the ulnar motor deep branch. The coexistence of carpal tunnel syndrome in each case allowed an early diagnosis but was somewhat misleading. In both cases, the use of classic motor and sensory conduction studies did not provide clear abnormalities that would have precisely determined the site of the nerve lesion. In both cases, only palmar stimulation of the ulnar motor deep branch showed an important conduction block. This electrodiagnostic finding showed definitively the site of the ulnar nerve lesion at the wrist and excluded proximal ulnar nerve lesions or C8-T1 radiculopathy. In both cases recovery occurred without surgery.

  15. Phase-Quantized Block Noncoherent Communication

    CERN Document Server

    Singh, Jaspreet

    2011-01-01

    Analog-to-digital conversion (ADC) is a key bottleneck in scaling DSP-centric receiver architectures to multiGigabit/s speeds. Recent information-theoretic results, obtained under ideal channel conditions (perfect synchronization, no dispersion), indicate that low-precision ADC (1-4 bits) could be a suitable choice for designing such high speed systems. In this work, we study the impact of employing low-precision ADC in a {\\it carrier asynchronous} system. Specifically, we consider transmission over the block noncoherent Additive White Gaussian Noise (AWGN) channel, and investigate the achievable performance under low-precision output quantization. We focus attention on an architecture in which the receiver quantizes {\\it only the phase} of the received signal: this has the advantage of being implementable without automatic gain control, using multiple 1-bit ADCs preceded by analog multipliers. For standard uniform Phase Shift Keying (PSK) modulation, we study the structure of the transition density of the re...

  16. Block copolymer templated etching on silicon.

    Science.gov (United States)

    Qiao, Yinghong; Wang, Dong; Buriak, Jillian M

    2007-02-01

    The use of self-assembled polymer structures to direct the formation of mesoscopic (1-100 nm) features on silicon could provide a fabrication-compatible means to produce nanoscale patterns, supplementing conventional lithographic techniques. Here we demonstrate nanoscale etching of silicon, applying standard aqueous-based fluoride etchants, to produce three-dimensional nanoscale features with controllable shapes, sizes, average spacing, and chemical functionalization. The block copolymers serve to direct the silicon surface chemistry by controlling the spatial location of the reaction as well as concentration of reagents. The interiors of the resulting etched nanoscale features may be selectively functionalized with organic monolayers, metal nanoparticles, and other materials, leading to a range of ordered arrays on silicon.

  17. Optimal information diffusion in stochastic block models

    CERN Document Server

    Curato, Gianbiagio

    2016-01-01

    We use the linear threshold model to study the diffusion of information on a network generated by the stochastic block model. We focus our analysis on a two community structure where the initial set of informed nodes lies only in one of the two communities and we look for optimal network structures, i.e. those maximizing the asymptotic extent of the diffusion. We find that, constraining the mean degree and the fraction of initially informed nodes, the optimal structure can be assortative (modular), core-periphery, or even disassortative. We then look for minimal cost structures, i.e. those such that a minimal fraction of initially informed nodes is needed to trigger a global cascade. We find that the optimal networks are assortative but with a structure very close to a core-periphery graph, i.e. a very dense community linked to a much more sparsely connected periphery.

  18. Observations on the SIMON Block Cipher Family

    DEFF Research Database (Denmark)

    Kölbl, Stefan; Leander, Gregor; Tiessen, Tyge

    2015-01-01

    In this paper we analyse the general class of functions underlying the Simon block cipher. In particular, we derive efficiently computable and easily implementable expressions for the exact differential and linear behaviour of Simon-like round functions. Following up on this, we use those...... expressions for a computer aided approach based on SAT/SMT solvers to find both optimal differential and linear characteristics for Simon. Furthermore, we are able to find all characteristics contributing to the probability of a differential for Simon32 and give better estimates for the probability for other...... variants. Finally, we investigate a large set of Simon variants using different rotation constants with respect to their resistance against differential and linear cryptanalysis. Interestingly, the default parameters seem to be not always optimal....

  19. Topology optimised planar photonic crystal building blocks

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Hede, K. K.; Borel, Peter Ingo

    A photonic crystal waveguide (PhCW) 1x4 splitter has been constructed from PhCW 60° bends1 and Y-splitters2 that have been designed individually by utilising topology optimisation3. The splitter has been fabricated in a silicon-on-insulator material (Fig. 1) and exhibits a broadband splitting...... for the TE-polarisation with an average excess loss of 1.55±0.54 dB for a 110 nm bandwidth. The 1x4 splitter demonstrates that individual topology-optimised parts can be used as building blocks to realise high-performance nanophotonic circuits. 1L. H. Frandsen et al., Opt. Express 12, 5916-5921 (2004) 2P. I...

  20. Snow and ice blocking of tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Lia, Leif

    1998-12-31

    Hydroelectric power development in cold regions causes much concern about operational reliability and dam safety. This thesis studies the temperature distribution in tunnels by means of air temperature measurements in six tunnel spillways and five diversion tunnels. The measurements lasted for two consecutive winters. The air through flow tunnel is used as it causes cooling of both rock and water. In open spillway tunnels, frost reaches the entire tunnel. In spillway tunnels with walls, the frost zones reach about 100 m from the downstream end. In mildly-inclined diversion tunnels, a frost free zone is located in the middle of the tunnel and snow and ice problems were only observed in the inlet and outlet. Severe aufeis is accumulation is observed in the frost zones. The heat transfer from rock to air, water and ice is calculated and used in a prediction model for the calculation of aufeis build-up together with local field observation data. The water penetration of snow plugs is also calculated, based on the heat balance. It takes 20 to 50 days for water to enter the blocked tunnel. The empirical values are 30 to 60 days, but only 1 day if the temperature of the snow pack is 0{sup o}C. Sensitivity analyses are carried out for temperature variations in rock, snow, water and ice. Systematic field observation shows that it is important for hydropower companies to know about the effects of snow and ice blocking in an area. A risk analysis of dam safety is presented for a real case. Finally, the thesis proposes solutions which can reduce the snow and ice problems. 79 refs., 63 figs., 11 tabs.

  1. Transient Presyncope Secondary to Posterior Descending Artery Occlusion

    Directory of Open Access Journals (Sweden)

    Andrew D. Moffat

    2011-01-01

    Full Text Available We describe the case of a 64-year-old male initially presenting with presyncope and bradycardia, without any anginal symptoms or objective evidence of myocardial ischemia. A stress test induced no physical symptoms but revealed a left bundle branch block with multiple preventricular contractions on electrocardiogram. Subsequent catheterization revealed severe obstructive disease throughout the coronary arteries. He was treated percutaneously on two separate heart catheterizations. The presyncope and bradycardia resolved after reperfusion of the posterior descending artery.

  2. Wolff-Parkinson-White Syndrome Mimics a Conduction Disease

    OpenAIRE

    Marrakchi, S.; I. Kammoun; S. Kachboura

    2014-01-01

    Background. It is important to recognise Wolff-Parkinson-White (WPW) syndrome in electrocardiograms (ECG), as it may mimic ischaemic heart disease, ventricular hypertrophy, and bundle branch block. Recognising WPW syndrome allows for risk stratification, the identification of associated conditions, and the institution of appropriate management. Objective. The present case showed that electrophysiological study is indicated in patients with abnormal ECG and syncope. Case Report. A 40-year-old ...

  3. Ablation of an atriofascicular accessory pathway with a zero-fluoroscopy procedure

    OpenAIRE

    PROIETTI, RICCARDO; Abadir, Sylvia; Bernier, Martin L.; Essebag, Vidal

    2015-01-01

    A 16-year-old patient with recurrent palpitations and documented left bundle branch block superior axis wide complex tachycardia underwent an electrophysiological study and ablation with a zero-fluoroscopy procedure. The electrophysiological study showed a decremental antegrade conducting atriofascicular pathway. Three-dimensional CARTO-guided mapping of the tricuspid annulus in sinus rhythm was performed, and a distinct signal corresponding to the accessory pathway potential of the atriofasc...

  4. Review and Updates in Regenerative and Personalized Medicine, Preclinical Animal Models, and Clinical Care in Cardiovascular Medicine.

    Science.gov (United States)

    Barbato, Emanuele; Barton, Paul J; Bartunek, Jozef; Huber, Sally; Ibanez, Borja; Judge, Daniel P; Lara-Pezzi, Enrique; Stolen, Craig M; Taylor, Angela; Hall, Jennifer L

    2015-11-01

    The goal of this paper is to provide an updated review for scientists and clinicians on the major areas in cardiovascular medicine published in the Journal. Leading topics in regenerative and personalized medicine are presented along with a critical overview of the field. New standards in large preclinical animal models of pulmonary hypertension and left bundle branch block are highlighted. Finally, clinical care in the areas of atherosclerosis, the aortic valve, platelet biology, and myocarditis is discussed as well as autonomic modulation therapies.

  5. Simple regional strain pattern analysis to predict response to cardiac resynchronization therapy

    DEFF Research Database (Denmark)

    Risum, Niels; Jons, Christian; Olsen, Niels T;

    2012-01-01

    A classical strain pattern of early contraction in one wall and prestretching of the opposing wall followed by late contraction has previously been associated with left bundle branch block (LBBB) activation and short-term response to cardiac resynchronization therapy (CRT). Aims of this study were...... to establish the long-term predictive value of an LBBB-related strain pattern and to identify changes in contraction patterns during short-term and long-term CRT....

  6. Case report: an unusual heart rhythm associated with organophosphate poisoning.

    Science.gov (United States)

    Gul, Enes Elvin; Can, Ilknur; Kusumoto, Fred M

    2012-09-01

    Organophosphate pesticides have emerged as a common cause of poisoning, particularly in developing countries. The most common electrocardiographic abnormalities observed in organophosphate poisoning are sinus tachycardia, QT interval prolongation, and, very rarely, ventricular arrhythmias. We report a case of organophosphate poisoning associated with atrial fibrillation, right bundle branch block, QT interval prolongation, and intermittent narrow QRS complexes that were most likely due to automaticity from the region of the left posterior fascicle.

  7. Massive pulmonary embolism immediately diagnosed by transthoracic echocardiography and treated with tenecteplase fibrinolysis.

    Science.gov (United States)

    Brunetti, Natale Daniele; Ieva, Riccardo; Correale, Michele; De Gennaro, Luisa; Pellegrino, Pier Luigi; Dioguardi, Ezio; Bux, Francesca; Di Biase, Matteo

    2009-08-01

    We report the case of a 75-year-old woman with new onset dyspnoea, hypotension, and right bundle branch block. Transthoracic echocardiography (TTE) showed a thrombus in the right pulmonary artery and acute pulmonary embolism was diagnosed. The patient immediately underwent fibrinolysis with tenecteplase, with prompt recovery of clinical conditions and ECG anomalies. Bedside TTE might be helpful for immediate diagnosis of massive PE needing rapid treatment by fibrinolysis.

  8. Robust and Adaptive Block Tracking Method Based on Particle Filter

    Directory of Open Access Journals (Sweden)

    Bin Sun

    2015-10-01

    Full Text Available In the field of video analysis and processing, object tracking is attracting more and more attention especially in traffic management, digital surveillance and so on. However problems such as objects’ abrupt motion, occlusion and complex target structures would bring difficulties to academic study and engineering application. In this paper, a fragmentsbased tracking method using the block relationship coefficient is proposed. In this method, we use particle filter algorithm and object region is divided into blocks initially. The contribution of this method is that object features are not extracted just from a single block, the relationship between current block and its neighbor blocks are extracted to describe the variation of the block. Each block is weighted according to the block relationship coefficient when the block is voted on the most matched region in next frame. This method can make full use of the relationship between blocks. The experimental results demonstrate that our method can provide good performance in condition of occlusion and abrupt posture variation.

  9. Galactic Building Blocks Seen Swarming Around Andromeda

    Science.gov (United States)

    2004-02-01

    Green Bank, WV - A team of astronomers using the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT) has made the first conclusive detection of what appear to be the leftover building blocks of galaxy formation -- neutral hydrogen clouds -- swarming around the Andromeda Galaxy, the nearest large spiral galaxy to the Milky Way. This discovery may help scientists understand the structure and evolution of the Milky Way and all spiral galaxies. It also may help explain why certain young stars in mature galaxies are surprisingly bereft of the heavy elements that their contemporaries contain. Andromeda Galaxy This image depicts several long-sought galactic "building blocks" in orbit of the Andromeda Galaxy (M31). The newfound hydrogen clouds are depicted in a shade of orange (GBT), while gas that comprises the massive hydrogen disk of Andromeda is shown at high-resolution in blue (Westerbork Sythesis Radio Telescope). CREDIT: NRAO/AUI/NSF, WSRT (Click on Image for Larger Version) "Giant galaxies, like Andromeda and our own Milky Way, are thought to form through repeated mergers with smaller galaxies and through the accretion of vast numbers of even lower mass 'clouds' -- dark objects that lack stars and even are too small to call galaxies," said David A. Thilker of the Johns Hopkins University in Baltimore, Maryland. "Theoretical studies predict that this process of galactic growth continues today, but astronomers have been unable to detect the expected low mass 'building blocks' falling into nearby galaxies, until now." Thilker's research is published in the Astrophysical Journal Letters. Other contributors include: Robert Braun of the Netherlands Foundation for Research in Astronomy; Rene A.M. Walterbos of New Mexico State University; Edvige Corbelli of the Osservatorio Astrofisico di Arcetri in Italy; Felix J. Lockman and Ronald Maddalena of the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia; and Edward Murphy of the

  10. Biobased building blocks for the rational design of renewable block polymers.

    Science.gov (United States)

    Holmberg, Angela L; Reno, Kaleigh H; Wool, Richard P; Epps, Thomas H

    2014-10-14

    Block polymers (BPs) derived from biomass (biobased) are necessary components of a sustainable future that relies minimally on petroleum-based plastics for applications ranging from thermoplastic elastomers and pressure-sensitive adhesives to blend compatibilizers. To facilitate their adoption, renewable BPs must be affordable, durable, processable, versatile, and reasonably benign. Their desirability further depends on the relative sustainability of the renewable resources and the methods employed in the monomer and polymer syntheses. Various strategies allow these BPs' characteristics to be tuned and enhanced for commercial applications, and many of these techniques also can be applied to manipulate the wide-ranging mechanical and thermal properties of biobased and self-assembling block polymers. From feedstock to application, this review article highlights promising renewable BPs, plus their material and assembly properties, in support of de novo design strategies that could revolutionize material sustainability.

  11. Synthesis and characterization of amphiphilc block copolymer poly(methyl acrylic acid)-block-polytetrahydrofuran

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Under the specially designated condition the polymerization of both tetrahydrofuran (THF) and tert-butyl methacrylate (tBMA) is a living one. The diblock copolymer, poly(tert-butyl methacrylate)-block-polytetrahydrofuran (PtBMA-b-PTHF), was successfully synthesized by means of the coupling reaction of living cationic PTHF+, SbF6- with living anionic PtBMA-, Li+. LiCl, which has a beneficial effect on the molecular weight distribution (MWD) in the anionic polymerization of (meth)acrylates, hinders the coupling reaction of living chains and cannot be used in the preparation of tBMA precursor. The hydrolysis of the aforementioned diblock copolymer under acid condition results in the amphiphilic diblock copolymer, i.e. poly(methyl acrylic acid)-block-polytetra- hydrofuran (PMAA-b-PTHF). The diblock copolymers were characterized with GPC and IR.

  12. Support agnostic Bayesian matching pursuit for block sparse signals

    KAUST Repository

    Masood, Mudassir

    2013-05-01

    A fast matching pursuit method using a Bayesian approach is introduced for block-sparse signal recovery. This method performs Bayesian estimates of block-sparse signals even when the distribution of active blocks is non-Gaussian or unknown. It is agnostic to the distribution of active blocks in the signal and utilizes a priori statistics of additive noise and the sparsity rate of the signal, which are shown to be easily estimated from data and no user intervention is required. The method requires a priori knowledge of block partition and utilizes a greedy approach and order-recursive updates of its metrics to find the most dominant sparse supports to determine the approximate minimum mean square error (MMSE) estimate of the block-sparse signal. Simulation results demonstrate the power and robustness of our proposed estimator. © 2013 IEEE.

  13. Continuous postoperative analgesia via quadratus lumborum block - an alternative to transversus abdominis plane block.

    Science.gov (United States)

    Visoiu, Mihaela; Yakovleva, Nataliya

    2013-10-01

    Different transversus abdominis plane blocks techniques cause variations in postoperative analgesia characteristics. We report the use of unilateral quadratus lumborum catheter for analgesia following colostomy closure. The catheter was placed under direct ultrasound visualization and had good outcomes: low pain scores and minimal use of rescue analgesic medication. No complications were reported in this pediatric patient. More studies are needed to evaluate the effectiveness and safety of this regional anesthesia technique.

  14. Nanostructured photovoltaic materials using block polymer assemblies

    Science.gov (United States)

    Mastroianni, Sarah Elizabeth

    Despite its potential as an abundant, sustainable alternative to non-renewable energy sources, solar energy currently is underutilized. Photovoltaics, which convert energy from sunlight into electricity, commonly are made from inorganic semiconductor materials that require expensive manufacturing and processing techniques. Alternatively, organic materials can be used to produce flexible and lightweight organic photovoltaic (OPV) devices, which can be prepared using solution-based processing techniques. However, OPV devices are limited by low efficiencies and short lifetimes compared to their inorganic counterparts. In OPV systems, charge carriers are generated in the active layer via the separation of excitons (electron-hole pairs) at interfaces between donor and acceptor materials. Because excitons have a limited diffusion length (˜10 nm), they may recombine before reaching a donor-acceptor interface if domain sizes are large. This exciton recombination can limit device efficiency; thus, the design parameters for improved active layer morphologies include large interfacial areas, small size scales, and continuous conducting pathways. Currently, most OPV devices are prepared by blending donor and acceptor materials in bulk heterojunction (BHJ) devices, often resulting in non-ideal, process-dependent morphologies. Alternatively, the self-assembly of block polymers (BP)s offers a reproducible means to generate nanostructured active layers. The work presented in this dissertation examines the synthetic approaches to preparing BPs containing different electroactive materials: non-conjugated, amorphous poly(vinyl-m-triphenylamine) [PVmTPA] and conjugated poly(3-alkythiophene) [P3AT] p-type materials as well as fullerene-based n-type materials. The synthesis and self-assembly of a model poly(methyl methacrylate)- b-PVmTPA system is presented. This work was extended to synthesize PVmTPA BPs with complementary poly(methyl methacrylate- co-hydroxyethyl methacrylate) [P

  15. [Subdural, extra-arachnoid block as a complication of stellate ganglion block: documentation with ultrasound].

    Science.gov (United States)

    Kapral, S; Krafft, P; Gosch, M; Fridrich, P; Weinstabl, C

    1997-10-01

    We present a patient who developed a high central neural block after stellate-ganglion-blockade. The underlying pathophysiology was assessed via sonographic imaging. Stellate ganglion block was performed in a 19-year old patient according to the standard technique. Multiple aspiration tests were negative and a test dose of 3 ml bupivacaine 0.25% was injected. After a 3 min interval another 5 ml were injected. Two minutes after the local anaesthetic administration the patient reported nausea and sensations in the upper extremity. Spontaneous respiration efforts stopped, and the patient became unconscious. Tracheal intubation was performed, and the patient was ventilated in a controlled mode for two hours. Heart rate as well as blood pressure remained within the normal range. Neurologic recovery occurred rapidly and extubation was performed about two and a half hours after the event. Our sonographic studies demonstrated a local anaesthetic depot directly at the root of C 6, with a mean diameter of 10 mm and a length of 5 to 6 cm (about a third smaller than expected). Sonographic studies and clinical symptoms of our patient are most likely to occur with a subdural extra-arachnoidal block. Ultrasonographic guided puncture enhances the patient's safety by the opportunity to directly visualise transverse process, nerval root as well as local anaesthetic depot. In case of depot formation directly at the nerval root, injection may be stopped and the needle repositioned. Furthermore, direct visualisation of the great vessels (A. vertebralis) prevents intravascular injection and haematoma formation.

  16. 块体与块体构造学说%BLOCK AND BLOCK TECTONICS

    Institute of Scientific and Technical Information of China (English)

    张训华; 孟祥君; 韩波

    2009-01-01

    从"块体"一词的使用历史和作为一级构造单元在构造区划中的应用出发,在系统总结刘光鼎综合地质一地球物理思想和研究成果基础上,将其学术思想归纳、概括、凝炼,提出了"块体构造学说";指出"块体构造学说"是在以活动论为内涵的全球构造思想指导下时"板块构造学说"的发展,并概括了在中国的实际应用.%On the basis of block concept and its use in tectonic division, and according to the integrated geology-geophysics ideology of LIU Guangding and his research achievements on China geotectonic evolutionary history, we tried to conclude and summarize his geotectonic ideology and named it "Block Tectonics". It is pointed that "Block Tectonics" is a practical application to China and it is the development of "Plate Tectonics" under the guidance of global tectonic ideology with activity theory as the connotation.

  17. Hydrophilic block azidation of PCL-b-PEO block copolymers from epichlorohydrin.

    Science.gov (United States)

    Liu, Junjie; Gan, Zhihua

    2014-05-01

    Amphiphilic diblock copolymers poly(ϵ-caprolactone)-b-poly(ethylene oxide) (PCL-b-PEO) with well-controlled pendant azido groups along the hydrophilic PEO block, that is, poly(ϵ-caprolactone)-b-poly(ethylene oxide-co-glycidyl azide) (PCL-b-P(EO-co-GA)), are synthesized from poly(ϵ-caprolactone)-b-poly(ethylene oxide-co-epichlorohydrin) (PCL-b-P(EO-co-ECH)). The further conversion of those azido groups along the hydrophilic block of copolymers into amino or carboxyl groups via click chemistry is studied. The micelles self-assembled from PCL-b-P(EO-co-GA) with azido groups on the shell are crosslinked by the dialkynyl-PEO. The micelles with crosslinked shell show better stability, higher drug loading capacities, subsequent faster drug release rate, and higher cytotoxicity to cancer cells. The introduction of azido groups into PCL-b-PEO amphiphilic diblock copolymers from epichlorohydrin in PEO hydrophilic block in this work provides a new method for biofunctionalization of micelles via mild click chemistry.

  18. Transversus abdominis plane block: a cadaveric and radiological evaluation.

    LENUS (Irish Health Repository)

    McDonnell, John G

    2011-04-11

    The abdominal wall is a significant source of pain after abdominal surgery. Anterior abdominal wall analgesia may assist in improving postoperative analgesia. We have recently described a novel approach to block the abdominal wall neural afferents via the bilateral lumbar triangles of Petit, which we have termed a transversus abdominis plane block. The clinical efficacy of the transversus abdominis plane block has recently been demonstrated in a randomized controlled clinical trial of adults undergoing abdominal surgery.

  19. Stopping Condition for Greedy Block Sparse Signal Recovery

    OpenAIRE

    Luo, Yu; Xie, Ronggui; Yin, Huarui; Wang, Weidong

    2016-01-01

    For greedy block sparse recovery where the sparsity level is unknown, we derive a stopping condition to stop the iteration process. Focused on the block orthogonal matching pursuit (BOMP) algorithm, we model the energy of residual signals at each iteration from a probabilistic perspective. At the iteration when the last supporting block is detected, the resulting energy of residual signals is supposed to suffer an obvious decrease. Based on this, we stop the iteration process when the energy ...

  20. An Asymmetric Block Dynamic Conditional Correlation Multivariate GARCH Model

    OpenAIRE

    Vargas, Gregorio A.

    2006-01-01

    The Block DCC model for determining dynamic correlations within and between groups of financial asset returns is extended to account for asymmetric effects. Simulation results show that the Asymmetric Block DCC model is competitive in in-sample forecasting and performs better than alternative DCC models in out-of-sample forecasting of conditional correlation in the presence of asymmetric effect between blocks of asset returns. Empirical results demonstrate that the model is able to capture ...

  1. Local implementation of nonlocal operations with block forms

    Science.gov (United States)

    Zhao, Ning Bo; Wang, An Min

    2008-07-01

    We investigate the local implementation of nonlocal operations with the block matrix form, and propose a protocol for any diagonal or offdiagonal block operation. We generalize this method to the two-party multiqubit case and the multiparty case. We also compare the local implementation of nonlocal block operations with the remote implementation of local operations [Huelga , Phys. Rev. A 63, 042303 (2001)], and point out a relation between them.

  2. Mechanisms and Rates of Plucking of Experimental Bedrock Blocks

    Science.gov (United States)

    Harbor, D. J.; Wilkinson, C.; Helgans, E.; Kuehner, J. P.

    2015-12-01

    Plucking in bedrock channels can be the dominant erosional mechanism but is difficult to predict numerically due to variation in block shape and orientation in the flow, and the general lack of experimental data compared to alluvial sediments. In a 250 cm-long, 14 cm-wide flume, we modeled bedrock channels using a bedrock test zone consisting of flow over an upstream step of 0 to 1.6 cm, a bed slope of 0.5 to1.24%, and a changing downstream backwater control on the location of a hydraulic jump. With flow velocity from 50 to 100 cm/s and depth from 3 to 10 cm, the low-density bedrock may well characterize natural bedrock plucking events in larger rivers in flood. Plucking initiated in critical to supercritical flow near hydraulic jumps. The first blocks to move lift from both the upstream and downstream sides and then other blocks slide both up- and downstream or laterally once neighbors are removed. Initiation of motion from each new bedrock slab began with different size and shape of blocks exhibiting no protrusion relative to the surrounding bed. Block erodibility increased with step height and channel slope and following the removal of the first block. A pressure gradient within the block mass near the jump and velocity differential within the channel margin set the stage for block uplift, but flow structures likely provide the variability that initiates lift. Preliminary flow visualization using Particle Image Velocimetry aids the understanding of flow structures contributing to blocks lift. Negative and positive feedback to further plucking was observed by erosion and deposition of plucked blocks. After their initial removal, blocks can accumulate downstream and slow the flow over the eroded reach or the position of jumps and jets shift with block removal to promote further plucking.

  3. Family control, multiple institutional block-holders, and informed trading

    OpenAIRE

    Zhang, X.; J. Piesse; Filatotchev, I.

    2015-01-01

    This paper investigates how large family shareholders and institutional block-holders jointly influence informed trading and firm valuation in the Hong Kong stock market. It combines market microstructure research with studies on the governance roles of multiple block-holders and finds that institutional block-holders rely on their relative controlling power vis-à-vis family owners to mitigate problems associated with informed trading. They also use their ownership rights to improve the struc...

  4. CAFS: A Cesium Atomic Frequency Standard for GPS block IIR

    Science.gov (United States)

    Wisnia, Jeffry A.

    1993-01-01

    Kernco, Inc. was selected to design the Cesium Atomic Frequency Standards (CAFS) for the GPS Block IIR NAVSTAR satellites. These spacecraft are scheduled to be launched in the mid-1990's to replenish and upgrade the existing constellation of Global Positioning System satellites. The Block IIR CAFS output frequency is 13.4003378 MHz, the 686th submultiple of the cesium atomic resonance frequency. Using an integer submultiple simplifies the design of the atomic frequency standard's rf multiplier circuits, eliminating the secondary frequency synthesizer needed in previous designs. The GPS Block IIR CAFS design, particularly the improvements made on our earlier Block II design is described. Test results are included.

  5. Chaotic block iterating method for pseudo-random sequence generator

    Institute of Scientific and Technical Information of China (English)

    CHEN Shuai; ZHONG Xian-xin

    2007-01-01

    A pseudo-random sequence generator is a basic tool for cryptography. To realize a pseudo-random sequence generator, a new block iterating method using shifter, multiplier,and adder operations has been introduced. By increasing the iteration of the counter and by performing calculations based on the initial value, an approximate pseudo-random sequence was obtained after exchanging bits. The algorithm and the complexity of the generator were introduced. The result obtained from the calculation shows that the self-correlation of the "m" block sequence is two-valued; the block field value is [0,2m - 1 ], and the block period is 2m+8 - 1.

  6. Exploring atmospheric blocking with GPS radio occultation observations

    Directory of Open Access Journals (Sweden)

    L. Brunner

    2015-12-01

    Full Text Available Atmospheric blocking has been closely investigated in recent years due to its impact on weather and climate, such as heat waves, droughts, and flooding. We use, for the first time, satellite-based observations from Global Positioning System (GPS radio occultation (RO and explore their ability to resolve blocking in order to potentially open up new avenues complementing models and re-analyses. RO delivers globally available and vertically high resolved profiles of atmospheric variables such as temperature and geopotential height (GPH. Applying a standard blocking detection algorithm we find that RO data robustly capture blocking as demonstrated for two well-known blocking events over Russia in summer 2010 and over Greenland in late winter 2013. During blocking episodes, vertically resolved GPH gradients show a distinct anomalous behavior compared to climatological conditions up to 300 hPa and sometimes even further up to the tropopause. The accompanied increase in GPH of up to 300 m in the upper troposphere yields a pronounced tropopause height increase. Corresponding temperatures rise up to 10 K in the middle and lower troposphere. These results demonstrate the feasibility and potential of RO to detect and resolve blocking and in particular to explore the vertical structure of the atmosphere during blocking episodes. This new observation-based view is available globally at the same quality so that also blocking in the Southern Hemisphere can be studied with the same reliability as in the Northern Hemisphere.

  7. Laparoscopic surgery and muscle relaxants: is deep block helpful?

    Science.gov (United States)

    Kopman, Aaron F; Naguib, Mohamed

    2015-01-01

    It has been hypothesized that providing deep neuromuscular block (a posttetanic count of 1 or more, but a train-of-four [TOF] count of zero) when compared with moderate block (TOF counts of 1-3) for laparoscopic surgery would allow for the use of lower inflation pressures while optimizing surgical space and enhancing patient safety. We conducted a literature search on 6 different medical databases using 3 search strategies in each database in an attempt to find data substantiating this proposition. In addition, we studied the reference lists of the articles retrieved in the search and of other relevant articles known to the authors. There is some evidence that maintaining low inflation pressures during intra-abdominal laparoscopic surgery may reduce postoperative pain. Unfortunately most of the studies that come to these conclusions give few if any details as to the anesthetic protocol or the management of neuromuscular block. Performing laparoscopic surgery under low versus standard pressure pneumoperitoneum is associated with no difference in outcome with respect to surgical morbidity, conversion to open cholecystectomy, hemodynamic effects, length of hospital stay, or patient satisfaction. There is a limit to what deep neuromuscular block can achieve. Attempts to perform laparoscopic cholecystectomy at an inflation pressure of 8 mm Hg are associated with a 40% failure rate even at posttetanic counts of 1 or less. Well-designed studies that ask the question "is deep block superior to moderate block vis-à-vis surgical operating conditions" are essentially nonexistent. Without exception, all the peer-reviewed studies we uncovered which state that they investigated this issue have such serious flaws in their protocols that the authors' conclusions are suspect. However, there is evidence that abdominal compliance was not increased by a significant amount when deep block was established when compared with moderate neuromuscular block. Maintenance of deep block for

  8. A Blocking Criterion for Self-Compacting Concrete

    DEFF Research Database (Denmark)

    Thrane, Lars Nyholm; Stang, Henrik; Geiker, Mette Rica

    2005-01-01

    To benefit from the full potential of Self-Compacting Concrete (SCC) prediction tools for the form filling ability of SCC are needed. This paper presents a theoretical concept for assessment of the blocking resistance of SCC. A critical concrete flow rate above which no blocking occurs is introdu......To benefit from the full potential of Self-Compacting Concrete (SCC) prediction tools for the form filling ability of SCC are needed. This paper presents a theoretical concept for assessment of the blocking resistance of SCC. A critical concrete flow rate above which no blocking occurs...

  9. Epidural block and neostigmine cause anastomosis leak

    Directory of Open Access Journals (Sweden)

    Ataro G

    2016-05-01

    Full Text Available Getu Ataro Department of Anesthesia, Jimma University, Jimma, EthiopiaI read the article by Phillips entitled, “Reducing gastrointestinal anastomotic leak rates: review of challenges and solutions”, published in the journal of Open Access Surgery with enthusiasm and found it crucial for perioperative management of patients with gastrointestinal (GI surgery, particularly anastomosis. I appreciate the author’s exhaustive search of literature and discussion with some limitation on review basics like methodology, which may affect the reliability of the review findings. The effects of risk factors for anastomosis leak, such as malnutrition, smoking, steroid use, bowel preparation, chemotherapy, duration of surgery, use of pressors, intravenous fluid administration, blood transfusion, and surgical anastomotic technique, were well discussed.1 However, from anesthesia perspective, there are some other well-studied risk factors that can affect healing of anastomosis wound and cause anastomosis leak. Among others, the effect of neostigmine and epidural block has been reported in many studies since half a century ago. View the original paper by Phillips

  10. Topological blocking in quantum quench dynamics

    Science.gov (United States)

    Kells, G.; Sen, D.; Slingerland, J. K.; Vishveshwara, S.

    2014-06-01

    We study the nonequilibrium dynamics of quenching through a quantum critical point in topological systems, focusing on one of their defining features: ground-state degeneracies and associated topological sectors. We present the notion of "topological blocking," experienced by the dynamics due to a mismatch in degeneracies between two phases, and we argue that the dynamic evolution of the quench depends strongly on the topological sector being probed. We demonstrate this interplay between quench and topology in models stemming from two extensively studied systems, the transverse Ising chain and the Kitaev honeycomb model. Through nonlocal maps of each of these systems, we effectively study spinless fermionic p-wave paired topological superconductors. Confining the systems to ring and toroidal geometries, respectively, enables us to cleanly address degeneracies, subtle issues of fermion occupation and parity, and mismatches between topological sectors. We show that various features of the quench, which are related to Kibble-Zurek physics, are sensitive to the topological sector being probed, in particular, the overlap between the time-evolved initial ground state and an appropriate low-energy state of the final Hamiltonian. While most of our study is confined to translationally invariant systems, where momentum is a convenient quantum number, we briefly consider the effect of disorder and illustrate how this can influence the quench in a qualitatively different way depending on the topological sector considered.

  11. Cylinder Block Fixture for Mistake Proofing.

    Directory of Open Access Journals (Sweden)

    L.B.Raut

    2014-10-01

    Full Text Available The project idea basically developed from trunnion tables which are one type of fixture having ability to rotate about its axis and able to fix the component at any angle, so there is no requirement of angle plate and sine plates, drilling process is also computer controlled so no guide bush is required, So robust design for extra rigidity, flexibility and simple to use. In this project task is difficult as design rotary cage type fixture for component like cylinder block, which is heavy of 76 kg. it is not possible to rotate or handle component manually and proceed on them to make this process accident proof and automated for this purpose we are designing a rotary cage which rotate 360 degree and allow indexing to process on the component. Processes are to be operated on the component are drilling tapping and air blow washing ,Since drilling don’t need clamping here components self weight will enough to carry drilling force and tapping force coming through power tools. Therefore, rotary cage type fixture is critical importance.

  12. Cavitation and pore blocking in nanoporous glasses.

    Science.gov (United States)

    Reichenbach, C; Kalies, G; Enke, D; Klank, D

    2011-09-06

    In gas adsorption studies, porous glasses are frequently referred to as model materials for highly disordered mesopore systems. Numerous works suggest that an accurate interpretation of physisorption isotherms requires a complete understanding of network effects upon adsorption and desorption, respectively. The present article deals with nitrogen and argon adsorption at different temperatures (77 and 87 K) performed on a series of novel nanoporous glasses (NPG) with different mean pore widths. NPG samples contain smaller mesopores and significantly higher microporosity than porous Vycor glass or controlled pore glass. Since the mean pore width of NPG can be tuned sensitively, the evolution of adsorption characteristics with respect to a broadening pore network can be investigated starting from the narrowest nanopore width. With an increasing mean pore width, a H2-type hysteresis develops gradually which finally transforms into a H1-type. In this connection, a transition from a cavitation-induced desorption toward desorption controlled by pore blocking can be observed. Furthermore, we find concrete hints for a pore size dependence of the relative pressure of cavitation in highly disordered pore systems. By comparing nitrogen and argon adsorption, a comprehensive insight into adsorption mechanisms in novel disordered materials is provided.

  13. Temperature alters Plasmodium blocking by Wolbachia

    Science.gov (United States)

    Murdock, Courtney C.; Blanford, Simon; Hughes, Grant L.; Rasgon, Jason L.; Thomas, Matthew B.

    2014-02-01

    Very recently, the Asian malaria vector (Anopheles stephensi) was stably transinfected with the wAlbB strain of Wolbachia, inducing refractoriness to the human malaria parasite Plasmodium falciparum. However, conditions in the field can differ substantially from those in the laboratory. We use the rodent malaria P. yoelii, and somatically transinfected An. stephensi as a model system to investigate whether the transmission blocking potential of wAlbB is likely to be robust across different thermal environments. wAlbB reduced malaria parasite prevalence and oocyst intensity at 28°C. At 24°C there was no effect on prevalence but a marked increase in oocyst intensity. At 20°C, wAlbB had no effect on prevalence or intensity. Additionally, we identified a novel effect of wAlbB that resulted in reduced sporozoite development across temperatures, counterbalancing the oocyst enhancement at 24°C. Our results demonstrate complex effects of temperature on the Wolbachia-malaria interaction, and suggest the impacts of transinfection might vary across diverse environments.

  14. Interband Plasmonics with p-block Elements

    CERN Document Server

    Toudert, Johann

    2016-01-01

    We investigate the origin of the near-ultraviolet visible plasmonic properties of three elemental materials from the p-block: Bi, Sb and Ga, with the aim to achieve and exploit unconventional plasmonic effects beyond those provided by noble metals. At such aim, we review and analyze a broad range of optically-determined dielectric functions e of these elemental materials available in the literature, covering a wide photon energy range (from 0.03 to 24 eV). It is shown that the contribution of Drude-like carriers to e1 (real part of e) in the near-ultraviolet visible is negligible for Bi and Sb and moderate for Ga. In contrast, the interband transitions of these elemental materials show a high oscillator strength that yields a strong negative contribution to e1 in the near-ultraviolet visible. Therefore in these materials interband transitions are not a mere damping channel detrimental to plasmonic properties. Remarkably, these interband transitions induce fully (partially) the localized surface plasmon-like r...

  15. Second demographic transition de-blocked?

    Directory of Open Access Journals (Sweden)

    Bobić Mirjana

    2011-01-01

    Full Text Available The text is re-examining the previously established dilemma related to whether Serbia (without Kosovo and Metohija is the country of second demographic transition, i.e.: has the transition been de-blocked, under the assumption that this is a worldwide historical process of transformation of industrialized countries. The last thesis, around which there exists a lot of controversy in the contemporary population theory, is however not dealt with in detail; to the contrary, it is used as the general theoretical framework for the exploration of the most recent tendencies in the transformation of nuptiality and fertility regime in Serbia, as well as in the western and countries in post-socialist transformation. Special attention is given to the ideational changes, more precisely to the specific features of the value profile of the Serbian population, which is one of the most important determinants of the societal framework, that acts in the back of the afore mentioned aggregate demographic indicators. Finally, the hypothesis is posed (which should be further investigated by means of in-depth research and complementary approach that the speeding-up of the second demographic transition and intensification of the individualisation not only of the partnership but of the parenthood as well, accompanied with the rise of living standard and social support to balancing work and family, would have produced important emancipating and, concomitantly, positive socioeconomic and demographic effects.

  16. Molecular Exchange Dynamics in Block Copolymer Micelles

    Science.gov (United States)

    Bates, Frank; Lu, Jie; Choi, Soohyung; Lodge, Timothy

    2012-02-01

    Poly(styrene-b-ethylene propylene) (PS-PEP) diblock copolymers were mixed with squalane (C30H62) at 1% by weight resulting in the formation of spherical micelles. The structure and dynamics of molecular exchange were characterized by synchrotron small-angle x-ray scattering (SAXS) and time resolved small-angle neutron scattering (TR-SANS), respectively, between 100 C and 160 C. TR-SANS measurements were performed with solutions initially containing deuterium labeled micelle cores and normal cores dispersed in a contrast matched squalane. Monitoring the reduction in scattering intensity as a function of time at various temperatures revealed molecular exchange dynamics highly sensitive to the core molecular weight and molecular weight distribution. Time-temperature superposition of data acquired at different temperatures produced a single master curve for all the mixtures. Experiments conducted with isotopically labeled micelle cores, each formed from two different but relatively mondisperse PS blocks, confirmed a simple dynamical model based on first order kinetics and core Rouse single chain relaxation. These findings demonstrate a dramatic transition to nonergodicity with increasing micelle core molecular weight and confirm the origins of the logarithmic exchange kinetics in such systems.

  17. Teaching engineering ethics using BLOCKS game.

    Science.gov (United States)

    Lau, Shiew Wei; Tan, Terence Peng Lian; Goh, Suk Meng

    2013-09-01

    The aim of this study was to investigate the use of a newly developed design game called BLOCKS to stimulate awareness of ethical responsibilities amongst engineering students. The design game was played by seventeen teams of chemical engineering students, with each team having to arrange pieces of colored paper to produce two letters each. Before the end of the game, additional constraints were introduced to the teams such that they faced similar ambiguity in the technical facts that the engineers involved in the Challenger disaster had faced prior to the space shuttle launch. At this stage, the teams had to decide whether to continue with their original design or to develop alternative solutions. After the teams had made their decisions, a video of the Challenger explosion was shown followed by a post-game discussion. The students' opinion on five Statements on ethics was tracked via a Five-Item Likert survey which was administered three times, before and after the ethical scenario was introduced, and after the video and post-game discussion. The results from this study indicated that the combination of the game and the real-life incident from the video had generally strengthened the students' opinions of the Statements.

  18. NOVEL SYNTHESIS OF LONG MULTI-BLOCK HETEROPOLYMER CHAINS WITH AN ORDERED SEQUENCE AND CONTROLLABLE BLOCK LENGTHS

    Institute of Scientific and Technical Information of China (English)

    Chi Wu; Zuo-wei Xie; Guang-zhao Zhang; Guo-fu Zi

    2001-01-01

    It had very long been a dream in polymer science to synthesize long multi-block polymer chains with an ordered chain sequence and controllable block lengths. Using ionic or living free radical polymerization or furnishing each end of polymer blocks with a reactive functional group, one can only prepare heteropolymer chains with few long blocks, such as diblock and triblock copolymers. The most plausible result so far was a pentablock copolymer. Recently, using a combination of polymer physics and synthetic chemistry, we have invented self-assembly assisted polycondensation (SAAP). This communication reports the results of using this novel method to connect 10-100 triblock polymer chains together to form long multi-block heteropolymer chains with an ordered sequence and controllable block lengths.``

  19. Comparison of Postoperative Analgesic Efficacy of Penile Block, Caudal Block and Intravenous Paracetamol for Circumcision: A prospective Randomized Study

    OpenAIRE

    Ahmet Hakan Haliloglu; Mehmet Ilker Gokce; Semih Tangal; Mehmet Salih Boga; Hakan Tapar; Ebru Aladag

    2013-01-01

    Purpose To evaluate the postoperative analgesic efficacy of penile block, caudal block and intravenous paracetamol administration following circumcision. Materials and Methods In this prospective randomized study a total of 159 patients underwent circumcision under general anesthesia at urology clinic of Ufuk University Faculty of Medicine and Sorgun State Hospital between May 2012 and September 2012. The patients were randomized to three groups to receive penile block (Group 1), caudal blo...

  20. Dynamics and sensitivity analysis of high-frequency conduction block

    Science.gov (United States)

    Ackermann, D. Michael; Bhadra, Niloy; Gerges, Meana; Thomas, Peter J.

    2011-10-01

    The local delivery of extracellular high-frequency stimulation (HFS) has been shown to be a fast acting and quickly reversible method of blocking neural conduction and is currently being pursued for several clinical indications. However, the mechanism for this type of nerve block remains unclear. In this study, we investigate two hypotheses: (1) depolarizing currents promote conduction block via inactivation of sodium channels and (2) the gating dynamics of the fast sodium channel are the primary determinate of minimal blocking frequency. Hypothesis 1 was investigated using a combined modeling and experimental study to investigate the effect of depolarizing and hyperpolarizing currents on high-frequency block. The results of the modeling study show that both depolarizing and hyperpolarizing currents play an important role in conduction block and that the conductance to each of three ionic currents increases relative to resting values during HFS. However, depolarizing currents were found to promote the blocking effect, and hyperpolarizing currents were found to diminish the blocking effect. Inward sodium currents were larger than the sum of the outward currents, resulting in a net depolarization of the nodal membrane. Our experimental results support these findings and closely match results from the equivalent modeling scenario: intra-peritoneal administration of the persistent sodium channel blocker ranolazine resulted in an increase in the amplitude of HFS required to produce conduction block in rats, confirming that depolarizing currents promote the conduction block phenomenon. Hypothesis 2 was investigated using a spectral analysis of the channel gating variables in a single-fiber axon model. The results of this study suggested a relationship between the dynamical properties of specific ion channel gating elements and the contributions of corresponding conductances to block onset. Specifically, we show that the dynamics of the fast sodium inactivation gate are

  1. Identification, characteristics and classification of cryogenic block streams

    Institute of Scientific and Technical Information of China (English)

    Stuart A. Harris

    2016-01-01

    ABSTRACT Cryogenic block streams consist of a stream of rocks superficially resembling a stream deposit but lacking a matrix, usually occurring on a valley or gully floor or on slopes that are less steep than the maximum angle of repose of coarse sediments. They are usually formed on perennially frozen ground, but can also occur as relict landforms. There are three main active kinds forming today,viz., Siberian and Tibetan dynamic rock streams and lag block streams. During their formation, the blocks in the active Siberian and Tibetan dynamic block streams move downslope at up to 1 m/a. They are forming today on the Tibetan Plateau and in the more arid parts of south-central Siberia, although the processes involved in the movement are different. In the case of the Tibetan type, individual blocks slide downslope over the substrate in winter on an icy coating in areas of minimal winter precipitation. The Siberian type develops in areas of 15–80 cm of winter snow cover and an MAAT (mean annual air temperature) of−4 °C to−17 °C. The movement is due to creep of snow and ice and collapse of the blocks downslope during thawing. Lag block streams are formed by meltwater flowing over the surface of sediment consisting primarily of larger blocks with a limited amount of interstitial sediment. The erosion of the matrix is primarily in the spring in areas of higher winter precipitation on 10°–30° slopes. The blocks remain stationary, but the interstitial sediment is washed out by strong seasonal flows of meltwater or rain to form an alluvial fan. The boulders undergo weathering and become more rounded in the process. Lag block streams can also develop without the presence of permafrost in areas with cold climates or glaciers. Block streams also occur as relict deposits in older deposits under various climatic regimes that are unsuitable for their formation today. An example of relict lag block streams with subangular to subrounded blocks occurs in gullies on the

  2. Revisiting the Climatology of Atmospheric Blocking in the Northern Hemisphere

    Institute of Scientific and Technical Information of China (English)

    Ho Nam CHEUNG; ZHOU Wen; Hing Yim MOK; Man Chi WU; Yaping SHAO

    2013-01-01

    In addition to the occurrence of atmospheric blocking,the climatology of the characteristics of blocking events,including duration,intensity,and extension,in four seasons over the Northern Hemisphere was analyzed for the period 1950-2009.The seasonality and spatial variations of these characteristics were studied according to their longitudinal distributions.In general,there were sharp discrepancies in the blocking characteristics between winter and summer,and these differences were more prominent over the Atlantic and Pacific Oceans.The blocking not only occurred more frequently but also underwent stronger amplification in winter; likewise,the blocking occurred less frequently and underwent weaker amplification in summer.There are very strong interrelationships among different blocking characteristics,suggesting that they are supported by similar physical factors.In addition,the relationship between blocking over different regions and East Asian circulation was examined.Ural-Siberia is a major blocking formation region in all seasons that may exert a downstream impact on East Asia.The impact is generally weak in summer,which is due to its lower intensity and smaller duration.However,the extratropical circulation over East Asia in summer can be disturbed persistently by the frequent occurrence of blocking over the Asian continent or the Western Pacific.In particular,the blocking frequency over the Western Pacific significantly increased during the study period.This climatological information provides a background for studying the impact of blocking on East Asian circulation under both present and future climate conditions.

  3. A Comparison of Jump Height, Takeoff Velocities, and Blocking Coverage in the Swing and Traditional Volleyball Blocking Techniques

    Directory of Open Access Journals (Sweden)

    Travis Ficklin

    2014-03-01

    Full Text Available The purpose of this study was to compare traditional and swing blocking techniques on center of mass (COM projectile motion and effective blocking area in nine healthy Division I female volleyball players. Two high-definition (1080 p video cameras (60 Hz were used to collect two-dimensional variables from two separate views. One was placed perpendicular to the plane of the net and the other was directed along the top of the net, and were used to estimate COM locations and blocking area in a plane parallel to the net and hand penetration through the plane of the net respectively. Video of both the traditional and swing techniques were digitized and kinematic variables were calculated. Paired samples t-tests indicated that the swing technique resulted in greater (p < 0.05 vertical and horizontal takeoff velocities (vy and vx, jump height (H, duration of the block (tBLOCK, blocking coverage during the block (C as well as hand penetration above and through the net’s plane (YPEN, ZPEN. The traditional technique had significantly greater approach time (tAPP. The results of this study suggest that the swing technique results in both greater jump height and effective blocking area. However, the shorter tAPP that occurs with swing is associated with longer times in the air during the block which may reduce the ability of the athlete to make adjustments to attacks designed to misdirect the defense.

  4. Nanostructured Polysulfone-Based Block Copolymer Membranes

    KAUST Repository

    Xie, Yihui

    2016-05-01

    The aim of this work is to fabricate nanostructured membranes from polysulfone-based block copolymers through self-assembly and non-solvent induced phase separation. Block copolymers containing polysulfone are novel materials for this purpose providing better mechanical and thermal stability to membranes than polystyrene-based copolymers, which have been exclusively used now. Firstly, we synthesized a triblock copolymer, poly(tert-butyl acrylate)-b-polsulfone-b-poly(tert-butyl acrylate) through polycondensation and reversible addition-fragmentation chain-transfer polymerization. The obtained membrane has a highly porous interconnected skin layer composed of elongated micelles with a flower-like arrangement, on top of the graded finger-like macrovoids. Membrane surface hydrolysis was carried out in a combination with metal complexation to obtain metal-chelated membranes. The copper-containing membrane showed improved antibacterial capability. Secondly, a poly(acrylic acid)-b-polysulfone-b-poly(acrylic acid) triblock copolymer obtained by hydrolyzing poly(tert-butyl acrylate)-b-polsulfone-b-poly(tert-butyl acrylate) formed a thin film with cylindrical poly(acrylic acid) microdomains in polysulfone matrix through thermal annealing. A phase inversion membrane was prepared from the same polymer via self-assembly and chelation-assisted non-solvent induced phase separation. The spherical micelles pre-formed in a selective solvent mixture packed into an ordered lattice in aid of metal-poly(acrylic acid) complexation. The space between micelles was filled with poly(acrylic acid)-metal complexes acting as potential water channels. The silver0 nanoparticle-decorated membrane was obtained by surface reduction, having three distinct layers with different particle sizes. Other amphiphilic copolymers containing polysulfone and water-soluble segments such as poly(ethylene glycol) and poly(N-isopropylacrylamide) were also synthesized through coupling reaction and copper0-mediated

  5. Sex Steroids Block the Initiation of Atherosclerosis.

    Science.gov (United States)

    Naftolin, Frederick; Mehr, Holly; Fadiel, Ahmed

    2016-12-01

    Atherosclerosis is the main cause of death in men and women. This so-called "hardening of the arteries" results from advanced atherogenesis, the accumulation and death of subendothelial fat-laden macrophages (vascular plaque). The macrophages are attracted as the result of signals from injured vessels recruiting and activating cells to quell the injury by inflammation. Among the recruited cells are circulating monocytes that may be captured by the formation of neural cell adhesion molecule (nCAM) tethers between the monocytes and vascular endothelium; the tethers are dependent on electrostatic binding between distal segments of apposed nCAM molecules. The capture of monocytes is followed by their entry into the subendothelial area as macrophages, many of which will remain and become the fat-laden foam cells in vascular plaque. Neural cell adhesion molecules are subject to sialylation that blocks their electrostatic binding. We showed that estradiol-induced nCAM sialylases are present in vascular endothelial cells and tested whether sex steroid pretreatment of human vascular endothelium could inhibit the capture of monocytes. Using in vitro techniques, pretreatment of human arterial endothelial cells with estradiol, testosterone, dehydroepiandrosterone and dihydrotestosterone all induced sialylation of endothelial cells and, in a dose-response manner, reduced the capture of monocytes. Steroid hormones are protective against atherogenesis and its sequellae. Sex steroid depletion is associated with atherosclerosis. Based on this knowledge plus our results using sex steroid pretreatment of endothelial cells, we propose that the blockade of the initial step in atherogenesis by sex steroid-induced nCAM sialylation may be crucial to hormonal prevention of atherosclerosis.

  6. Visible Geology - Interactive online geologic block modelling

    Science.gov (United States)

    Cockett, R.

    2012-12-01

    Geology is a highly visual science, and many disciplines require spatial awareness and manipulation. For example, interpreting cross-sections, geologic maps, or plotting data on a stereonet all require various levels of spatial abilities. These skills are often not focused on in undergraduate geoscience curricula and many students struggle with spatial relations, manipulations, and penetrative abilities (e.g. Titus & Horsman, 2009). A newly developed program, Visible Geology, allows for students to be introduced to many geologic concepts and spatial skills in a virtual environment. Visible Geology is a web-based, three-dimensional environment where students can create and interrogate their own geologic block models. The program begins with a blank model, users then add geologic beds (with custom thickness and color) and can add geologic deformation events like tilting, folding, and faulting. Additionally, simple intrusive dikes can be modelled, as well as unconformities. Students can also explore the interaction of geology with topography by drawing elevation contours to produce their own topographic models. Students can not only spatially manipulate their model, but can create cross-sections and boreholes to practice their visual penetrative abilities. Visible Geology is easy to access and use, with no downloads required, so it can be incorporated into current, paper-based, lab activities. Sample learning activities are being developed that target introductory and structural geology curricula with learning objectives such as relative geologic history, fault characterization, apparent dip and thickness, interference folding, and stereonet interpretation. Visible Geology provides a richly interactive, and immersive environment for students to explore geologic concepts and practice their spatial skills.; Screenshot of Visible Geology showing folding and faulting interactions on a ridge topography.

  7. Thoracic sympathetic block reduces respiratory system compliance

    Directory of Open Access Journals (Sweden)

    Fábio Ely Martins Benseñor

    Full Text Available CONTEXT AND OBJECTIVE: Thoracic epidural anesthesia (TEA following thoracic surgery presents known analgesic and respiratory benefits. However, intraoperative thoracic sympathetic block may trigger airway hyperreactivity. This study weighed up these beneficial and undesirable effects on intraoperative respiratory mechanics. DESIGN AND SETTING: Randomized, double-blind clinical study at a tertiary public hospital. METHODS: Nineteen patients scheduled for partial lung resection were distributed using a random number table into groups receiving active TEA (15 ml 0.5% bupivacaine, n = 9 or placebo (15 ml 0.9% saline, n = 10 solutions that also contained 1:200,000 epinephrine and 2 mg morphine. Under general anesthesia, flows and airway and esophageal pressures were recorded. Pressure-volume curves, lower inflection points (LIP, resistance and compliance at 10 ml/kg tidal volume were established for respiratory system, chest wall and lungs. Student’s t test was performed, including confidence intervals (CI. RESULTS: Bupivacaine rose 5 ± 1 dermatomes upwards and 6 ± 1 downwards. LIP was higher in the bupivacaine group (6.2 ± 2.3 versus 3.6 ± 0.6 cmH2O, p = 0.016, CI = -3.4 to -1.8. Respiratory system and lung compliance were higher in the placebo group (respectively 73.3 ± 10.6 versus 51.9 ± 15.5, p = 0.003, CI = 19.1 to 23.7; 127.2 ± 31.7 versus 70.2 ± 23.1 ml/cmH2O, p < 0.001, CI = 61 to 53. Resistance and chest wall compliance showed no difference. CONCLUSION: TEA decreased respiratory system compliance by reducing its lung component. Resistance was unaffected. Under TEA, positive end-expiratory pressure and recruitment maneuvers are advisable.

  8. Block Based Symmetry Key Visual Cryptography

    Directory of Open Access Journals (Sweden)

    Satyendra Nath Mandal

    2012-08-01

    Full Text Available Visual cryptography is a method for protecting image-based secrets that has a computation-free decoding process. In this technique, numbers of shares have been generated from one image. The shares are sent through any channel to the receiver and the receiver can again produce original image by stacking all the shares in proper order. But, this method wastes a lot of bandwidth of the network. The techniques of generating shares have been used in several existing methods which are not unique. The different methods have been used in different types of images like binary, gray and color images. In this paper, a block based symmetry key visual cryptography algorithm has been proposed to convert image in encrypted form and decrypt the encrypted image into original form. The symmetric key has been generated from a real number. The encryption and decryption algorithm have been designed based on symmetry key. The algorithm with key has been used to encrypt image into single share and decrypt the single share into original image. The real number has been used to form the key may be predefined or may be sent by secure channel to the receiver. The proposed algorithm can be applied to any type images i.e. binary, gray scale and color images. A comparison has been made of the proposed algorithm with different existing algorithms like Ceaser cipher, transpose of matrix, bit comp, and transposition cipher based on the performance. The pixels distributed in original and share images have also been tested. Finally, it has shown that breaking of security level of proposed algorithm i.e. to guess the real number is huge time consuming.

  9. The New Block Cipher Design (Tigris Cipher

    Directory of Open Access Journals (Sweden)

    Omar A. Dawood

    2015-11-01

    Full Text Available In the present paper we have proposed a new variant of AES cipher with high level of security and an elegant construction called TIGRIS cipher. The TIGRIS name has been derived from one of the two famous rivers in Iraq. The proposed TIGRIS cipher is a revision for the proposed Euphrates cipher which has already been published. It has been designed with a good coherent structure that is based on solid algebraic and well mathematical opinions. The proposed cipher uses the SPN structure and what is known by the Galois Field GF (28. It is an iterated cipher that has a conservative design which is easily implemented on both hardware and software. It operates with block size of 128-bits and with three variable key lengths of 128-bits, 192-bits and 256-bits in addition to sixteen rounds or multiples of four rounds. The proposed cipher works with good invertible operations' stages and a compact duplicated ciphering key. The Tigris cipher construction strategy includes the adoption of construction a new S-box with high non-linearity that uses the same routines of the AES-S-box stage but with different modular arithmetic of irreducible polynomial and different affine matrix in addition to the distinct constant vector. The second and the third layers of the proposed model are based on the shifting concept for the confusion and diffusion process with reversible operations. The last layer of the proposed model is the key addition layer that is responsible for the expanding and generating the ciphering key by two directions those of row and column expansion, which are associated with two constant vectors of golden ratio and base nature algorithm as a fixed word to eliminate any weak or semi-weak ciphering key.

  10. Automatic Blocking Of QR and LU Factorizations for Locality

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Q; Kennedy, K; You, H; Seymour, K; Dongarra, J

    2004-03-26

    QR and LU factorizations for dense matrices are important linear algebra computations that are widely used in scientific applications. To efficiently perform these computations on modern computers, the factorization algorithms need to be blocked when operating on large matrices to effectively exploit the deep cache hierarchy prevalent in today's computer memory systems. Because both QR (based on Householder transformations) and LU factorization algorithms contain complex loop structures, few compilers can fully automate the blocking of these algorithms. Though linear algebra libraries such as LAPACK provides manually blocked implementations of these algorithms, by automatically generating blocked versions of the computations, more benefit can be gained such as automatic adaptation of different blocking strategies. This paper demonstrates how to apply an aggressive loop transformation technique, dependence hoisting, to produce efficient blockings for both QR and LU with partial pivoting. We present different blocking strategies that can be generated by our optimizer and compare the performance of auto-blocked versions with manually tuned versions in LAPACK, both using reference BLAS, ATLAS BLAS and native BLAS specially tuned for the underlying machine architectures.

  11. Dimensioning of multiservice links taking account of soft blocking

    DEFF Research Database (Denmark)

    Iversen, Villy Bæk; Stepanov, S.N.; Kostrov, A.V.

    2006-01-01

    of a multiservice link taking into account the possibility of soft blocking. An approximate algorithm for estimation of main performance measures is constructed. The error of estimation is numerically studied for different types of soft blocking. The optimal procedure of dimensioning is suggested....

  12. Second-Degree Interatrial Block in Hemodialysis Patients

    Directory of Open Access Journals (Sweden)

    Andres Enriquez

    2015-01-01

    Full Text Available Interatrial conduction delays manifest as a prolonged P-wave duration on surface ECG and the term interatrial block (IAB has been coined. They are usually fixed, but cases of intermittent IAB have been described, suggesting functional conduction block at the Bachmann bundle region. We report 2 cases of patients on chronic hemodialysis therapy presenting with intermittent IAB.

  13. Second-Degree Interatrial Block in Hemodialysis Patients

    Science.gov (United States)

    Enriquez, Andres; D'Amato, Anna; de Luna, Antoni Bayes; Baranchuk, Adrian

    2015-01-01

    Interatrial conduction delays manifest as a prolonged P-wave duration on surface ECG and the term interatrial block (IAB) has been coined. They are usually fixed, but cases of intermittent IAB have been described, suggesting functional conduction block at the Bachmann bundle region. We report 2 cases of patients on chronic hemodialysis therapy presenting with intermittent IAB. PMID:25755895

  14. [Electrical nerve stimulation for plexus and nerve blocks].

    Science.gov (United States)

    Birnbaum, J; Klotz, E; Bogusch, G; Volk, T

    2007-11-01

    Despite the increasing use of ultrasound, electrical nerve stimulation is commonly used as the standard for both plexus and peripheral nerve blocks. Several recent randomized trials have contributed to a better understanding of physiological and clinical correlations. Traditionally used currents and impulse widths are better defined in relation to the distance between needle tip and nerves. Commercially available devices enable transcutaneous nerve stimulation and provide new opportunities for the detection of puncture sites and for training. The electrically ideal position of the needle usually is defined by motor responses which can not be interpreted without profound anatomical knowledge. For instance, interscalene blocks can be successful even after motor responses of deltoid or pectoral muscles. Infraclavicular blocks should be aimed at stimulation of the posterior fascicle (extension). In contrast to multiple single nerve blocks, axillary single-shot blocks more commonly result in incomplete anaesthesia. Blockade of the femoral nerve can be performed without any nerve stimulation if the fascia iliaca block is used. Independently of the various approaches to the sciatic nerve, inversion and plantar flexion are the best options for single-shot blocks. Further clinical trials are needed to define the advantages of stimulating catheters in continuous nerve blocks.

  15. Bochdalek Hernia As A Cause Of Intermittent AV Block

    OpenAIRE

    Etsadashvili, Kakhaber; Rashid, Haroon Mohammed; Jalabadze, Khatuna; Melia, Anzor

    2011-01-01

    Congenital diaphragmatic hernia is very rare cause of AV block. We report such a patient with sick sinus node syndrome and previous AAIR pacemaker implantation, in which intermittent AV block was diagnosed by 24-hours ECG monitoring and upgrade of pacing system to DDDR was suggested.

  16. The influence of the Gulf Stream on wintertime European blocking

    Science.gov (United States)

    O'Reilly, Christopher H.; Minobe, Shoshiro; Kuwano-Yoshida, Akira

    2016-09-01

    Wintertime blocking is responsible for extended periods of anomalously cold and dry weather over Europe. In this study, the influence of the Gulf Stream sea surface temperature (SST) front on wintertime European blocking is investigated using a reanalysis dataset and a pair of atmospheric general circulation model (AGCM) simulations. The AGCM is forced with realistic and smoothed Gulf Stream SST, and blocking frequency over Europe is found to depend crucially on the Gulf Stream SST front. In the absence of the sharp SST gradient European blocking is significantly reduced and occurs further downstream. The Gulf Stream is found to significantly influence the surface temperature anomalies during blocking periods and the occurrence of associated cold spells. In particular the cold spell peak, located in central Europe, disappears in the absence of the Gulf Stream SST front. The nature of the Gulf Stream influence on European blocking development is then investigated using composite analysis. The presence of the Gulf Stream SST front is important in capturing the observed quasi-stationary development of European blocking. The development is characterised by increased lower-tropospheric meridional eddy heat transport in the Gulf Stream region and increased eddy kinetic energy at upper-levels, which acts to reinforce the quasi-stationary jet. When the Gulf Stream SST is smoothed the storm track activity is weaker, the development is less consistent and European blocking occurs less frequently.

  17. Transient handover blocking probabilities in road covering cellular mobile networks

    NARCIS (Netherlands)

    Boucherie, Richard J.; Wal, van der Jan

    2003-01-01

    This paper investigates handover and fresh call blocking probabilities for subscribers moving along a road in a traffic jam passing through consecutive cells of a wireless network. It is observed and theoretically motivated that the hand- over blocking probabilities show a sharp peak in the initial

  18. Transient handover blocking probabilities in road covering cellular mobile networks

    NARCIS (Netherlands)

    Boucherie, R.J.; Wal, van der J.

    2002-01-01

    This paper investigates handover and fresh call blocking probabilities for subscribers moving along a road in a traffic jam passing through consecutive cells of a wireless network. It is observed and theoretically motivated that the handover blocking probabilities show a sharp peak in the initial pa

  19. Self-assembled materials from thermosensitive and biohybrid block copolymers

    NARCIS (Netherlands)

    de Graaf, A.J.

    2012-01-01

    In this research, several block copolymers were synthesized and characterized with regard to possible pharmaceutical applications. All block copolymers were thermosensitive and self-assembled at 37 °C into structures like micelles and hydrogels, which can be used for innovative drug delivery purpose

  20. DNA Island Formation on Binary Block Copolymer Vesicles.

    Science.gov (United States)

    Luo, Qingjie; Shi, Zheng; Zhang, Yitao; Chen, Xi-Jun; Han, Seo-Yeon; Baumgart, Tobias; Chenoweth, David M; Park, So-Jung

    2016-08-17

    Here, we report DNA-induced polymer segregation and DNA island formation in binary block copolymer assemblies. A DNA diblock copolymer of polymethyl acrylate-block-DNA (PMA-b-DNA) and a triblock copolymer of poly(butadiene)-block-poly(ethylene oxide)-block-DNA (PBD-b-PEO-b-DNA) were synthesized, and each was coassembled with a prototypical amphiphilic polymer of poly(butadiene)-block-poly(ethylene oxide) (PBD-b-PEO). The binary self-assembly of PMA-b-DNA and PBD-b-PEO resulted in giant polymersomes with DNA uniformly distributed in the hydrophilic PEO shell. When giant polymersomes were connected through specific DNA interactions, DNA block copolymers migrated to the junction area, forming DNA islands within polymersomes. These results indicate that DNA hybridization can induce effective lateral polymer segregation in mixed polymer assemblies. The polymer segregation and local DNA enrichment have important implications in DNA melting properties, as mixed block copolymer assemblies with low DNA block copolymer contents can still exhibit useful DNA melting properties that are characteristic of DNA nanostructures with high DNA density.

  1. High Order Differential Attack and Trace Attack to Block Ciphers

    Institute of Scientific and Technical Information of China (English)

    HU Yupu; CHEN Kai; Xiao Guozhen

    2001-01-01

    In this paper, we prove a high or-der differential property of power function, then giverespectively high order differential attack and traceattack to block ciphers. These attacks depend onlyon block cipher's algebraic shape on GF(2n) and haveno relation with its designing structure. The condi-tions are given for both effective attacks and strengthagainst attacks.

  2. Survey and benchmark of block ciphers for wireless sensor networks

    NARCIS (Netherlands)

    Law, Yee Wei; Doumen, Jeroen; Hartel, Pieter

    2004-01-01

    Choosing the most storage- and energy-efficient block cipher specifically for wireless sensor networks (WSNs) is not as straightforward as it seems. To our knowledge so far, there is no systematic evaluation framework for the purpose. In this paper, we have identified the candidates of block ciphers

  3. Benchmarking Block Ciphers for Wireless Sensor Networks (Extended Abstract)

    NARCIS (Netherlands)

    Law, Y.W.; Doumen, J.M.; Hartel, P.H.

    2004-01-01

    Choosing the most storage- and energy-efficient block cipher specifically for wireless sensor networks (WSNs) is not as straightforward as it seems. To our knowledge so far, there is no systematic evaluation framework for the purpose. We have identified the candidates of block ciphers suitable for W

  4. Explicit filtering of building blocks for genetic algorithms

    NARCIS (Netherlands)

    Kemenade, C.H.M. van

    1996-01-01

    Genetic algorithms are often applied to building block problems. We have developed a simple filtering algorithm that can locate building blocks within a bit-string, and does not make assumptions regarding the linkage of the bits. A comparison between the filtering algorithm and genetic algorithms re

  5. 21 CFR 177.1810 - Styrene block polymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Styrene block polymers. 177.1810 Section 177.1810... FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1810 Styrene block polymers. The...

  6. Trihaloethenes as versatile building blocks for organic synthesis.

    Science.gov (United States)

    Grossmann, Adriana S; Magauer, Thomas

    2016-06-15

    This review highlights the chemistry of trihaloethene building blocks with a special focus on commercially available 1,1,2-trichloroethene. The topics surveyed herein include the use of trihaloethenes as C2-building blocks for transition metal-catalyzed coupling reactions, addition, elimination and cycloaddition reactions as well as natural product syntheses.

  7. Hierarchical structure formation in supramolecular comb-shaped block copolymers

    NARCIS (Netherlands)

    Hofman, Anton; ten Brinke, Gerrit; Loos, Katja

    2016-01-01

    Block copolymers are known to spontaneously form ordered structures at the nano-to mesoscale. Although the number of different morphologies is rather limited in diblock copolymer systems, their phase behavior becomes increasingly more complex with each additional building block. Synthesis of such al

  8. Prognostic importance of complete atrioventricular block complicating acute myocardial infarction

    DEFF Research Database (Denmark)

    Aplin, Mark; Engstrøm, Thomas; Vejlstrup, Niels G

    2003-01-01

    Third-degree atrioventricular block after acute myocardial infarction is considered to have prognostic importance. However, its importance in conjunction with thrombolytic therapy and its relation to left ventricular function remains uncertain. This report also outlines an important distinction...... between atrioventricular block in the setting of anterior and inferior wall acute myocardial infarction, with profound clinical and prognostic implications....

  9. Diltiazem and verapamil preferentially block inactivated cardiac calcium channels.

    Science.gov (United States)

    Kanaya, S; Arlock, P; Katzung, B G; Hondeghem, L M

    1983-02-01

    Diltiazem has been proposed to act by blocking calcium channels of cardiac and smooth muscle since it has pharmacological [12-14] and clinical [10] effects that resemble those of verapamil, an agent that has been shown to block these channels [3]. However, block of the slow inward current by diltiazem has not been directly demonstrated. In fact, it has been suggested that diltiazem has an entirely different mechanism of action [7]. We therefore studied the blocking effects of diltiazem and verapamil on cardiac calcium channels by measuring the slow inward current in voltage-clamped ferret myocardium. Both drugs blocked the slow inward current in a use-dependent fashion, i.e. the block was enhanced by increased frequency of activating clamps and by more positive holding potentials. However, we found that short single activating clamps resulted in minimal block, whereas prolonging the clamp step progressively enhanced the blockade. Thus, a single long clamp caused as much blockade as a train of shorter pulses. These results demonstrate that diltiazem and verapamil block the slow inward current by binding to calcium channels in a state-dependent fashion, i.e. inactivated channels have a high affinity for the drugs, while rested and open channels have a lower affinity.

  10. Metal nanoparticle - block copolymer composite assembly and disassembly

    NARCIS (Netherlands)

    Li, Z.H.; Sai, H.; Warren, S.C.; Kamperman, M.M.G.; Arora, H.; Gruner, S.M.; Wiesner, U.

    2009-01-01

    Ligand-stabilized platinum nanoparticles (Pt NPs) were self-assembled with poly(isoprene-block-dimethylaminoethyl methacrylate) (PI-b-PDMAEMA) block copolymers to generate organic-inorganic hybrid materials. High loadings of NPs in hybrids were achieved through usage of N,N-di-(2-(allyloxy)ethyl)-N-

  11. DYNAMIC DESIGN OF INTERNAL COMBUSTION ENGINE BLOCK STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Several main steps of internal combustion engine block structure dynamic design,such as model set-up,structure dynamic response analysis,optimizing design and vibration and noise control,are discussed for the type of EQ6100 gasoline engine block.

  12. Girlhood, Sexual Violence, and Agency in Francesca Lia Block's "Wolf"

    Science.gov (United States)

    Marshall, Elizabeth

    2009-01-01

    This essay examines the representation of adolescent girlhood, sexual violence and agency in Francesca Lia Block's contemporary fairy tale collection "The Rose and The Beast." Focusing specifically on the tale "Wolf," the author provides a literary analysis of how Block draws on and reworks traditional Western fairy tale variants to reintroduce…

  13. Reports on block rotations, fault domains and crustal deformation

    Science.gov (United States)

    Nur, Amos

    1990-01-01

    Studies of block rotations, fault domains and crustal deformation in the western United States, Israel, and China are discussed. Topics include a three-dimensional model of crustal fracture by distributed fault sets, distributed deformation and block rotation in 3D, stress field rotation, and multiple strike slip fault sets.

  14. Perpendicularly Aligned, Anion Conducting Nanochannels in Block Copolymer Electrolyte Films

    Energy Technology Data Exchange (ETDEWEB)

    Arges, Christopher G.; Kambe, Yu; Suh, Hyo Seon; Ocola, Leonidas E.; Nealey, Paul F.

    2016-03-08

    Connecting structure and morphology to bulk transport properties, such as ionic conductivity, in nanostructured polymer electrolyte materials is a difficult proposition because of the challenge to precisely and accurately control order and the orientation of the ionic domains in such polymeric films. In this work, poly(styrene-block-2-vinylpyridine) (PSbP2VP) block copolymers were assembled perpendicularly to a substrate surface over large areas through chemical surface modification at the substrate and utilizing a versatile solvent vapor annealing (SVA) technique. After block copolymer assembly, a novel chemical vapor infiltration reaction (CVIR) technique selectively converted the 2-vinylpyridine block to 2-vinyl n-methylpyridinium (NMP+ X-) groups, which are anion charge carriers. The prepared block copolymer electrolytes maintained their orientation and ordered nanostructure upon the selective introduction of ion moieties into the P2VP block and post ion-exchange to other counterion forms (X- = chloride, hydroxide, etc.). The prepared block copolymer electrolyte films demonstrated high chloride ion conductivities, 45 mS cm(-1) at 20 degrees C in deionized water, the highest chloride ion conductivity for anion conducting polymer electrolyte films. Additionally, straight-line lamellae of block copolymer electrolytes were realized using chemoepitaxy and density multiplication. The devised scheme allowed for precise and accurate control of orientation of ionic domains in nanostructured polymer electrolyte films and enables a platform for future studies that examines the relationship between polymer electrolyte structure and ion transport.

  15. Development of traffic induced permanent strain in concrete block pavements

    NARCIS (Netherlands)

    Huurman, M.

    1996-01-01

    Concrete block pavements (c.b.p.) commonly consist of concrete blocks placed over a granular substructure. As a result of wheel load passages permanent strains will slowly develop in the substructure and cause rutting. This paper is about the prediction of the permanent strain development in the sub

  16. Steps for Improving School Climate in Block Scheduling.

    Science.gov (United States)

    Queen, J. Allen; Kaskey, Kimberly A.

    1997-01-01

    Developing a block schedule and surviving its first year of implementation require an open mind, a flexible spirit, and commitment. Discusses the basics of block scheduling; curricular alignment, course development, and unit design; pacing guides for time management; instruction strategies and lesson designs; classroom management; advanced…

  17. Recursive representation of the torus 1-point conformal block

    CERN Document Server

    Hadasz, Leszek; Suchanek, Paulina

    2009-01-01

    The recursive relation for the 1-point conformal block on a torus is derived and used to prove the identities between conformal blocks recently conjectured by R. Poghossian. As an illustration of the efficiency of the recurrence method the modular invariance of the 1-point Liouville correlation function is numerically analyzed.

  18. Synthesis and characterization of ferrocene containing block copolymers

    DEFF Research Database (Denmark)

    Chernyy, Sergey; Wang, Zhongli; Kirkensgaard, Jacob Judas Kain

    2017-01-01

    Narrowly dispersed diblock copolymers containing poly(methyl methacrylate) [PMMA] or poly(nonafluorohexyl methacrylate) [PF9MA] as the first block and poly(ferrocenylmethyl methacrylate) [PFMMA] as the second block, were prepared by anionic polymerization for the first time. Disordered bulk morph...

  19. Building a Case for Blocks as Kindergarten Mathematics Learning Tools

    Science.gov (United States)

    Kinzer, Cathy; Gerhardt, Kacie; Coca, Nicole

    2016-01-01

    Kindergarteners need access to blocks as thinking tools to develop, model, test, and articulate their mathematical ideas. In the current educational landscape, resources such as blocks are being pushed to the side and being replaced by procedural worksheets and academic "seat time" in order to address standards. Mathematics research…

  20. Rapidly Progressive Atrioventricular Block in a Patient with Sarcoidosis

    Directory of Open Access Journals (Sweden)

    Nagham Saeed Jafar

    2014-01-01

    Full Text Available Cardiac sarcoidosis is a major cause of death in patients with systemic sarcoidosis. Cardiac manifestations are seen in 2.3% of the patients. Atrioventricular (AV block is one of the common manifestations of cardiac sarcoidosis. Other presentations of cardiac involvement include congestive heart failure, ventricular arrhythmias, and sudden cardiac death. The presence of AV block in young patients should raise the suspicion of sarcoidosis. AV block may be the only manifestation and patients may not have clinical evidence of pulmonary involvement. Here we describe a young male presented with exercise induced AV block rapidly progressing to complete heart block with recurrent syncope needing urgent pacemaker implantation. Factors that suggested an infiltrative process included his young age, rapidly progressive conduction abnormalities in the ECG in the absence of coronary disease, and previous history of cutaneous sarcoidosis.

  1. Stabilized Lateritic Blocks Reinforced With Fibrous Coir Wastes

    Directory of Open Access Journals (Sweden)

    M G Sreekumar

    2013-11-01

    Full Text Available Tropical countries are rich in lateritic soil, a naturally available raw material for building construction. But its potential in block making is not yet satisfactorily explored. This paper focuses on an experimental investigation for improvising stabilized lateritic blocks (SLB with coir cutting wastes from coir industry as reinforcing elements. Lateritic soil used in this study showed a higher percentage of clay content. Hence it was pre-stabilized with sand and cement. Blocks were prepared by stabilizing it further with waste fibrous additives and tested for strength and durability. Considerable improvement in strength (compressive strength @19% and tensile strength @ 9% and durability characteristics were exhibited by the new fiber reinforced lateritic blocks (FRLB with fiber content of 0.5%. These blocks can be successfully proposed for load bearing construction and as well as for earthquake resistant structures

  2. Study of the Optimal Precursors for Blocking Events

    Institute of Scientific and Technical Information of China (English)

    JIANG Zhina; LUO Dehai

    2005-01-01

    The precursors of dipole blocking are obtained by a numerical approach based upon a quasi-geostrophic barotropic planetary- to synoptic-scale interaction model without topography and with a localized synopticscale wave-maker. The optimization problem related to the precursors of blocking is formulated and the nonlinear optimization method is used to examine the optimal synoptic-scale initial field successfully. The results show that the prominent characteristics of the optimal synoptic-scale initial field are that the synoptic-scale wave train structures exist upstream of the incipient blocking. In addition, the large-scale low/high eddy-forcing pattern upstream of the incipient blocking is an essential precondition for the onset of dipole blocking.

  3. COMPRESSIVE AND SHEAR ANALYSIS OF RUBBER BLOCK UNDER LARGE STRAIN

    Directory of Open Access Journals (Sweden)

    K. Sridharan

    2013-01-01

    Full Text Available The Elastomeric materials have found use in a wide range of applications, including hoses, tires, gaskets, seals, vibration isolators, bearings and dock fenders. The analysis of rubber blocks for its compression and shear behavior has been carried out using the imaging techniques. The dynamic stressing and its associated change in shape of the rubber blocks during large compression are very limited as their measurements were difficult. A newly developed Machine Vision based image processing test has been effectively used to study the deformation characteristics of the rubber blocks under large strains. An extended analysis on the rubber blocks has been carried out to understand the compression and deformation behavior in static and dynamic condition and the nonlinear behavior were also characterized. The rubber blocks of distinguished geometries have shown diverse change in shape and nonlinear deformation behavior under compression/shear loading.

  4. Unexpected motor weakness following quadratus lumborum block for gynaecological laparoscopy.

    Science.gov (United States)

    Wikner, M

    2017-02-01

    Quadratus lumborum block has recently been described as an effective and long-lasting analgesic strategy for various abdominal operations, including gynaecological laparoscopy. Despite evidence that the analgesic effect is mediated by indirect paravertebral block and that local anaesthetic spreads to the lumbar paravertebral space, there have been no reports to date of lower limb motor weakness. We present a patient with unilateral hip flexion and knee extension weakness leading to unplanned overnight admission following lateral quadratus lumborum block with 20 ml levobupivacaine 0.25%. The L2 dermatomal sensory loss and hip flexion weakness suggested spread to either the L2 paravertebral space or to the lumbar plexus, causing weakness of the psoas and iliacus muscles and possibly the quadriceps. The duration of motor block was approximately 18 h. This complication should be considered when performing the block, especially in the setting of day-case surgery.

  5. Ultrasound-guided peripheral nerve blocks: what are the benefits?

    DEFF Research Database (Denmark)

    Nielsen, Zbigniew Jerzy Koscielniak

    2008-01-01

    BACKGROUND: Use of ultrasound by anaesthesiologists performing regional blocks is rapidly gaining popularity. The aims of this review were to summarize and update accumulating evidence on ultrasound-guided nerve blocks, with an emphasis on the clinical relevance of the results and to critically...... appraise changing standards in regional anaesthesia. METHODS: A search of MEDLINE and EMBASE (1966 to 31 December 2007) was conducted using the following free terms: 'ultrasound and regional anesthesia', 'ultrasound and peripheral block' and 'ultrasound and nerve and block'. These were combined......, the concomitant use of nerve stimulation offers no further advantage. However, several studies reported problems with obtaining satisfactory images in some patients. Ultrasound guidance significantly shortened the block performance time and/or reduced the number of needle passes to reach the target in all...

  6. Fungal contamination of paraffin wax blocks in a pathology archive.

    Science.gov (United States)

    Müller, K; Ellenberger, C; Aupperle, H; Schmäschke, R; Scheller, R; Wittenbrink, M M; Schoon, H-A

    2011-01-01

    While searching for paraffin wax blocks for research purposes in our archive we detected numerous larval and some dead adult moths. Some wax blocks were riddled with a white-brown crumbling substance. The entire archive was checked and profoundly-infested blocks were separated from unaffected blocks. Mycological and parasitological investigations were performed. Fungi were identified by culture and polymerase chain reaction, which revealed high sequence homology to six different fungal species. The moths were determined to be Nemapogon personellus. A total of 8,484 wax blocks had to be removed from the archive and destroyed. Pathologists should be alerted to the importance of checking the humidity of the air where archival material is stored.

  7. BlockLogo: Visualization of peptide and sequence motif conservation

    DEFF Research Database (Denmark)

    Olsen, Lars Rønn; Kudahl, Ulrich Johan; Simon, Christian

    2013-01-01

    BlockLogo is a web-server application for the visualization of protein and nucleotide fragments, continuous protein sequence motifs, and discontinuous sequence motifs using calculation of block entropy from multiple sequence alignments. The user input consists of a multiple sequence alignment......, selection of motif positions, type of sequence, and output format definition. The output has BlockLogo along with the sequence logo, and a table of motif frequencies. We deployed BlockLogo as an online application and have demonstrated its utility through examples that show visualization of T-cell epitopes...... and B-cell epitopes (both continuous and discontinuous). Our additional example shows a visualization and analysis of structural motifs that determine the specificity of peptide binding to HLA-DR molecules. The BlockLogo server also employs selected experimentally validated prediction algorithms...

  8. On new exact conformal blocks and Nekrasov functions

    Science.gov (United States)

    Nemkov, Nikita

    2016-12-01

    Recently, an intriguing family of the one-point toric conformal blocks AGT related to the N = 2∗SU(2) Nekrasov functions was discovered by M. Beccaria and G. Macorini. Members of the family are distinguished by having only finite amount of poles as functions of the intermediate dimension/v.e.v. in gauge theory. Another remarkable property is that these conformal blocks/Nekrasov functions can be found in closed form to all orders in the coupling expansion. In the present paper we use Zamolodchikov's recurrence equation to systematically account for these exceptional conformal blocks. We conjecture that the family is infinite-dimensional and describe the corresponding parameter set. We further apply the developed technique to demonstrate that the four-point spheric conformal blocks feature analogous exact expressions. We also study the modular transformations of the finite-pole blocks.

  9. New adhesive systems based on functionalized block copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Kent, M.; Saunders, R.; Hurst, M.; Small, J.; Emerson, J.; Zamora, D.

    1997-05-01

    The goal of this work was to evaluate chemically-functionalized block copolymers as adhesion promoters for metal/thermoset resin interfaces. Novel block copolymers were synthesized which contain pendant functional groups reactive toward copper and epoxy resins. In particular, imidazole and triazole functionalities that chelate with copper were incorporated onto one block, while secondary amines were incorporated onto the second block. These copolymers were found to self-assemble from solution onto copper surfaces to form monolayers. The structure of the adsorbed monolayers were studied in detail by neutron reflection and time-of-flight secondary ion mass spectrometry. The monolayer structure was found to vary markedly with the solution conditions and adsorption protocol. Appropriate conditions were found for which the two blocks form separate layers on the surface with the amine functionalized block exposed at the air surface. Adhesion testing of block copolymer-coated copper with epoxy resins was performed in both lap shear and peel modes. Modest enhancements in bond strengths were observed with the block copolymer applied to the native oxide. However, it was discovered that the native oxide is the weak link, and that by simply removing the native oxide, and then applying an epoxy resin before the native oxide can reform, excellent bond strength in the as-prepared state as well as excellent retention of bond strength after exposure to solder in ambient conditions are obtained. It is recommended that long term aging studies be performed with and without the block copolymer. In addition, the functionalized block copolymer method should be evaluated for another system that has inherently poor bonding, such as the nickel/silicone interface, and for systems involving metals and alloys which form oxides very rapidly, such as aluminum and stainless steel, where bonding strategies involve stabilizing the native oxide.

  10. Block circulant and block Toeplitz approximants of a class of spatially distributed systems-An LQR perspective

    NARCIS (Netherlands)

    Iftime, Orest V.

    2012-01-01

    In this paper block circulant and block Toeplitz long strings of MIMO systems with finite length are compared with their corresponding infinite-dimensional spatially invariant systems. The focus is on the convergence of the sequence of solutions to the control Riccati equations and the convergence o

  11. Effect of Adductor Canal Block Versus Femoral Nerve Block on Quadriceps Strength, Mobilization, and Pain After Total Knee Arthroplasty

    DEFF Research Database (Denmark)

    Grevstad, Jens Ulrik; Mathiesen, Ole; Valentiner, Laura Risted Staun;

    2015-01-01

    BACKGROUND AND OBJECTIVES: Total knee arthroplasty (TKA) is often associated with severe pain. Different regional anesthetic techniques exist, all with varying degrees of motor blockade. We hypothesized that pain relief provided by the adductor canal block (ACB) could increase functional muscle....... CONCLUSION: Adductor canal block provides a clinically relevant and statistically significant increase in quadriceps muscle strength for patients in severe pain after TKA....

  12. Two cell cycle blocks caused by iron chelation of neuroblastoma cells: separating cell cycle events associated with each block.

    Science.gov (United States)

    Siriwardana, Gamini; Seligman, Paul A

    2013-12-01

    Studies have presented evidence that besides the well described S phase block, treatment of cancer cell lines with the iron chelator deferrioxamine (DFO) also results in an earlier block in G1 phase. In this article, measurements of cell cycle regulatory proteins define this block at a very specific point in G1. DFO treatment results in markedly decreased cyclin A protein levels. Cyclin E levels that accumulate in early to mid-G1 are increased in cells treated with DFO as compared to the resting cells. The DFO S phase block is shown after cells are arrested at G1/S by (aphidicolin) then released into DFO. The same S phase block occurs with DFO treatment of a neuroblastoma cell line relatively resistant to the G1 DFO block. These experiments clearly differentiate the S phase DFO block from the earlier block pinpointed to a point in mid-G1, before G1/S when cyclin E protein increases but before increased cyclin A synthesis. Apoptosis was observed in cells inhibited by DFO at both cell cycle arrest points.

  13. Improvement of cylinder block line for high productivity. Koseisansei cylinder block seizo line no kakuritsu

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, M. (Aisin Takaoka Co. Ltd., Tokyo (Japan)); Ito, M. (Toyota Motor Corp., Aichi (Japan))

    1991-05-25

    This paper is a technical report of improvig manufacturing line in an automotive cylinder block casting factory, and enhancing the productivity. Gists of the improvement can be summarized in the following three items: Standardization of the production corresponding to product acceptance condition by the subsequent process; elimination of waste in time by means of establishing production framework, including material handling; and accumulation of small scale automations. The result was the productivity in 1989 increased by 1.2 times that in around 1975 as a result of improved rate of operation, and number of workers reduced to half, supported particularly by manpower saving in core making and finishing processes. For instance, core making machines were given size reduction in the facility and die, and multiple core making function, in which one die makes different cores for the same part. The multiple core making function, which can reduce number of machines necessary to make one cylinder block, has a large advantage not only facilitating arrangemets for small quantity production parts, but also dealing with stepwise capacity increase and eliminating the necessity of keeping spare dies. 16 figs., 1 tab.

  14. Poly(lactide)-block-poly([epsilon]-caprolactone-co-[epsilon]-decalactone)-block-poly(lactide) copolymer elastomers

    Energy Technology Data Exchange (ETDEWEB)

    Schneiderman, Deborah K.; Hill, Erin M.; Martello, Mark T.; Hillmyer, Marc A. (UMM)

    2015-08-28

    Batch ring opening transesterification copolymerization of ε-caprolactone and ε-decalactone was used to generate statistical copolymers over a wide range of compositions and molar masses. Reactivity ratios determined for this monomer pair, rCL = 5.9 and rDL = 0.03, reveal ε-caprolactone is added preferentially regardless of the propagating chain end. Relative to poly(ε-caprolactone) the crystallinity and melting point of these statistical copolymers were depressed by the addition of ε-decalactone; copolymers containing greater than 31 mol% (46 wt%) ε-decalactone were amorphous. Poly(lactide)-block-poly(ε-caprolactone-co-ε-decalactone)-block-poly(lactide) triblock polymers were also prepared and used to explore the influence of midblock composition on the temperature dependent Flory-Huggins interaction parameter (χ). In addition, uniaxial extension tests were used to determine the effects of midblock composition, poly(lactide) content, and molar mass on the mechanical properties of these new elastomeric triblocks.

  15. Pectoralis Minor Nerve Block versus Thoracic Epidural and Paravertebral Block in Perioperative Pain Control of Breast Surgery - Mini Review

    Directory of Open Access Journals (Sweden)

    Rafik Sedra

    2015-03-01

    Full Text Available Pectoralis minor blocks are still relatively new and require further evaluation, but may have a place in peri-operative pain management for the appropriate cases. Still considered as less invasive procedure in comparison to thoracic epidurals and para-vertebral blocks. Complications of thoracic epidural and para-vertebral blocks like spinal cord injury and pneumothorax makes many anaesthetists interested in practising pectoralis minor block guided by ultrasound. Blanco first introduced the pectoralis minor block in 2011, he did study on 50 patients within 2 years. Results were very promising, all patients did not need any opiates but only paracetamol and non-steroidal anti-inflammatory (NSAID drugs got used.

  16. Model of rigid and elastic-plastic motion in intraplate blocks and strain status of principal blocks in Chinese mainland

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The model of rigid and elastic-plastic motion and strain in intraplate blocks is established in the paper. The unique of strain parameters and minimum root-mean-square error of velocity residual of blocks are tested in the model. Based on the velocity fields in Chinese mainland and its peripheral areas, the strain parameters of 8 blocks are estimated and their strain status analyzed. The estimated strain status of each block is well consistent with those derived by the methods of geology and geophysics. The principal direction of collision force from India plate to Eurasia plate estimated from the azimuth of principal compressive strain of Himalaya block might be N7.1°E.

  17. Chain exchange kinetics of block copolymer micelles in ionic liquids

    Science.gov (United States)

    Ma, Yuanchi; Lodge, Timothy

    The chain exchange kinetics of block copolymer micelles has been studied using time-resolved small-angle neutron scattering (TR-SANS), a key tool in determining the average micelle composition in contrast-matched solvents. In this work, PMMA-block-PnBMA was selected as the model block copolymer, which has a LCST behavior in the common ionic liquids, [EMIM][TFSI] and [BMIM][TFSI]. We examined the chain exchange kinetics of three PMMA-block-PnBMA copolymers, with identical PMMA block length (MPMMA = 25000) and different PnBMA block lengths (MPnBMA = 24000, 35000 and 53000); the Flory-Huggins interaction parameter (χ) between the core (PnBMA) and the solvent were varied by mixing [EMIM][TFSI] and [BMIM][TFSI] in different ratios. We found that the relaxation of the initial segregation of h- and d- micelles followed the same form with the time as previously developed by our group. Assuming that single chain expulsion is the rate limiting step, the thermal barrier was found to depend linearly on the core block length (Ncore) . Furthermore, the effect of χ on the chain exchange kinetics will also be discussed.

  18. NANOSTRUCTURED METAL OXIDE CATALYSTS VIA BUILDING BLOCK SYNTHESES

    Energy Technology Data Exchange (ETDEWEB)

    Craig E. Barnes

    2013-03-05

    A broadly applicable methodology has been developed to prepare new single site catalysts on silica supports. This methodology requires of three critical components: a rigid building block that will be the main structural and compositional component of the support matrix; a family of linking reagents that will be used to insert active metals into the matrix as well as cross link building blocks into a three dimensional matrix; and a clean coupling reaction that will connect building blocks and linking agents together in a controlled fashion. The final piece of conceptual strategy at the center of this methodology involves dosing the building block with known amounts of linking agents so that the targeted connectivity of a linking center to surrounding building blocks is obtained. Achieving targeted connectivities around catalytically active metals in these building block matrices is a critical element of the strategy by which single site catalysts are obtained. This methodology has been demonstrated with a model system involving only silicon and then with two metal-containing systems (titanium and vanadium). The effect that connectivity has on the reactivity of atomically dispersed titanium sites in silica building block matrices has been investigated in the selective oxidation of phenols to benezoquinones. 2-connected titanium sites are found to be five times as active (i.e. initial turnover frequencies) than 4-connected titanium sites (i.e. framework titanium sites).

  19. Corner block list representation and its application with boundary constraints

    Institute of Scientific and Technical Information of China (English)

    HONG Xianlong; MA Yuchun; DONG Sheqin; CAI Yici; Chung-Kuan Cheng; GU Jun

    2004-01-01

    Floorplanning is a critical phase in physical design of VLSI circuits. The stochastic optimization method is widely used to handle this NP-hard problem. The key to the floorplanning algorithm based on stochastic optimization is to encode the floorplan structure properly. In this paper, corner block list (CBL)-a new efficient topological representation for non-slicing floorplan-is proposed with applications to VLSI floorplan.Given a corner block list, it takes only linear time to construct the floorplan. In floorplanning of typical VLSI design, some blocks are required to satisfy some constraints in the final packing. Boundary constraint is one kind of those constraints to pack some blocks along the pre-specified boundaries of the final chip so that the blocks are easier to be connected to certain I/O pads. We implement the boundary constraint algorithm for general floorplan by extending CBL. Our contribution is to find the necessary and sufficient characterization of the blocks along the boundary represented by CBL. We can check the boundary constraints by scanning the intermediate solutions in linear time during the simulated annealing process and fix the corner block list in case the constraints are violated. The experiment results are demonstrated by several examples of MCNC benchmarks and the performance is remarkable.

  20. Ship Block Transportation Scheduling Problem Based on Greedy Algorithm

    Directory of Open Access Journals (Sweden)

    Chong Wang

    2016-05-01

    Full Text Available Ship block transportation problems are crucial issues to address in reducing the construction cost and improving the productivity of shipyards. Shipyards aim to maximize the workload balance of transporters with time constraint such that all blocks should be transported during the planning horizon. This process leads to three types of penalty time: empty transporter travel time, delay time, and tardy time. This study aims to minimize the sum of the penalty time. First, this study presents the problem of ship block transportation with the generalization of the block transportation restriction on the multi-type transporter. Second, the problem is transformed into the classical traveling salesman problem and assignment problem through a reasonable model simplification and by adding a virtual node to the proposed directed graph. Then, a heuristic algorithm based on greedy algorithm is proposed to assign blocks to available transporters and sequencing blocks for each transporter simultaneously. Finally, the numerical experiment method is used to validate the model, and its result shows that the proposed algorithm is effective in realizing the efficient use of the transporters in shipyards. Numerical simulation results demonstrate the promising application of the proposed method to efficiently improve the utilization of transporters and to reduce the cost of ship block logistics for shipyards.

  1. Moisture and Thermal Conductivity of Lightweight Block Walls

    Science.gov (United States)

    Joosep, R.

    2015-11-01

    This article examines thermal properties of lightweight block walls and their changes over the course of time. Three different types of lightweight blocks and two types of heat insulation are used in construction. Aeroc aerated concrete blocks are in use, as well as compacted LECA (Lightweight Expanded Clay Aggregate) Fibo blocks made from burned clay and Silbet blocks produced from oil shale ash. Expanded Thermisol EPS60F polystyrene plates and glass wool Isover OL-P plates are used for thermal insulation. The actual and computational values of thermal conductivity and the water draining properties of walls over time are compared in this article. Water draining from glass wool walls is relatively fast. Water-draining can take over a year in polystyrene insulated walls. All four wall constructions can be used as external walls, but care must be taken regarding the moisture content of the blocks during construction (the construction should be handled with care to minimise the moisture in the blocks), especially in polystyrene board-insulated walls.

  2. ANALYSIS OF CELL BLOCK VS . CONVENTIONAL SMEAR IN FLUID CYTOLOGY

    Directory of Open Access Journals (Sweden)

    Jyotsna

    2015-09-01

    Full Text Available BACKGROUND: The cytological examination of aspirates of serous effusions is a routinely accepted , simple , safe and minimally invasive technique . Diagnosis in this investigation , especially in malignant effusions , helps in staging , prognosis and management of the patients . AIMS: To assess the utility and sensitivity of cell block method over conventional smear technique in cytodiagnosis of the serous effusions . METHODS: A total of 72 fluid specimens were subjected to simultaneous processing by conventional s mear and cell block technique . Each fluid specimen was divided into two equal parts and results compared for cellularity , cell architecture , cytoplasmic and nuclear features . Cell blocks were prepared using modified cell block technique using alcohol forma lin fixative . RESULTS: The utility of cell block technique in diagnosing malignant effusions is highly significant as compared to the conventional smear technique . Also , the technique using alcohol formalin fixative is simple , safe and these chemicals are routinely used in laboratory . CONCLUSION: Cell block technique is superior to conventional smear technique , especially for malignant effusions . It gives more information about the architectural arrangement and the likely source of primary . More important is that diagnostic material in cell blocks is available for special studies for . I mmunohistochemistry which can further supplement our knowledge about the primary source of metastasis

  3. Bulk Vitrification Castable Refractory Block Protection Study

    Energy Technology Data Exchange (ETDEWEB)

    Hrma, Pavel R.; Bagaasen, Larry M.; Beck, Andrew E.; Brouns, Thomas M.; Caldwell, Dustin D.; Elliott, Michael L.; Matyas, Josef; Minister, Kevin BC; Schweiger, Michael J.; Strachan, Denis M.; Tinsley, Bronnie P.; Hollenberg, Glenn W.

    2005-05-01

    Bulk vitrification (BV) was selected for a pilot-scale test and demonstration facility for supplemental treatment to accelerate the cleanup of low-activity waste (LAW) at the Hanford U.S. DOE Site. During engineering-scale (ES) tests, a small fraction of radioactive Tc (and Re, its nonradioactive surrogate) were transferred out of the LAW glass feed and molten LAW glass, and deposited on the surface and within the pores of the castable refractory block (CRB). Laboratory experiments were undertaken to understand the mechanisms of the transport Tc/Re into the CRB during vitrification and to evaluate various means of CRB protection against the deposition of leachable Tc/Re. The tests used Re as a chemical surrogate for Tc. The tests with the baseline CRB showed that the molten LAW penetrates into CRB pores before it converts to glass, leaving deposits of sulfates and chlorides when the nitrate components decompose. Na2O from the LAW reacts with the CRB to create a durable glass phase that may contain Tc/Re. Limited data from a single CRB sample taken from an ES experiment indicate that, while a fraction of Tc/Re is present in the CRB in a readily leachable form, most of the Tc/Re deposited in the refractory is retained in the form of a durable glass phase. In addition, the molten salts from the LAW, mainly sulfates, chlorides, and nitrates, begin to evaporate from BV feeds at temperatures below 800 C and condense on solid surfaces at temperatures below 530 C. Three approaches aimed at reducing or preventing the deposition of soluble Tc/Re within the CRB were proposed: metal lining, sealing the CRB surface with a glaze, and lining the CRB with ceramic tiles. Metal liners were deemed unsuitable because evaluations showed that they can cause unacceptable distortions of the electric field in the BV system. Sodium silicate and a low-alkali borosilicate glaze were selected for testing. The glazes slowed down molten salt condensate penetration, but did little to reduce the

  4. Massive hemothorax: A rare complication after supraclavicular brachial plexus block.

    Science.gov (United States)

    Singh, Shiv Kumar; Katyal, Surabhi; Kumar, Amit; Kumar, Pawan

    2014-01-01

    Plexus block is the preferred anesthesia plan for upper limb surgeries. Among the known complications, hematoma formation following the vascular trauma is often occur but this complication is frequently underreported. We present a case where a massive hemothorax developed post operatively in a patient who underwent resection of giant cell tumor of the right hand radius bone followed by arthroplasty under brachial plexus block using supraclavicular approach. This case report attempts to highlight the essence of remaining vigilant postoperatively for first initial days after brachial plexus block, especially after failed or multiple attempts. Ultrasound guided technique in combination with nerve stimulator has proven to be more reliable and safer than traditional techniques.

  5. Contract for Development of Zhaodong Block Signed in Beijing

    Institute of Scientific and Technical Information of China (English)

    Liu Guoan

    2001-01-01

    @@ Contract for development, equipment and construction of Zhaodong cooperative block was signed in Beijing on July 12, 2001. This is the first onshore oil foreign cooperation project in China that has been put into development. Apache (China) Company,foreign operator of the cooperation block, and No. 1 Engineering Construction Company of Shengli Petroleum Administration Bureau,contractor of the block, have reached the agreement on drilling rig platform in the beach land. The signing of the contract marked a substantial progress of Zhaodong development project.

  6. Block Toeplitz Determinants, Constrained KP and Gelfand-Dickey Hierarchies

    Energy Technology Data Exchange (ETDEWEB)

    Cafasso, M. [SISSA-International School for Advanced Studies (Italy)], E-mail: cafasso@sissa.it

    2008-02-15

    We propose a method for computing any Gelfand-Dickey {tau} function defined on the Segal-Wilson Grassmannian manifold as the limit of block Toeplitz determinants associated to a certain class of symbols W(t,z). Also truncated block Toeplitz determinants associated to the same symbols are shown to be {tau} functions for rational reductions of KP. Connection with Riemann-Hilbert problems is investigated both from the point of view of integrable systems and block Toeplitz operator theory. Examples of applications to algebro-geometric solutions are given.

  7. Multicore Performance of Block Algebraic Iterative Reconstruction Methods

    DEFF Research Database (Denmark)

    Sørensen, Hans Henrik B.; Hansen, Per Christian

    2014-01-01

    Algebraic iterative methods are routinely used for solving the ill-posed sparse linear systems arising in tomographic image reconstruction. Here we consider the algebraic reconstruction technique (ART) and the simultaneous iterative reconstruction techniques (SIRT), both of which rely...... on semiconvergence. Block versions of these methods, based on a partitioning of the linear system, are able to combine the fast semiconvergence of ART with the better multicore properties of SIRT. These block methods separate into two classes: those that, in each iteration, access the blocks in a sequential manner...

  8. Diagonal Limit for Conformal Blocks in d Dimensions

    CERN Document Server

    Hogervorst, Matthijs; Rychkov, Slava

    2013-01-01

    Conformal blocks in any number of dimensions depend on two variables z, zbar. Here we study their restrictions to the special "diagonal" kinematics z = zbar, previously found useful as a starting point for the conformal bootstrap analysis. We show that conformal blocks on the diagonal satisfy ordinary differential equations, third-order for spin zero and fourth-order for the general case. These ODEs determine the blocks uniquely and lead to an efficient numerical evaluation algorithm. For equal external operator dimensions, we find closed-form solutions in terms of finite sums of 3F2 functions.

  9. Block copolymer adhesion promoters via ring-opening metathesis polymerization

    Science.gov (United States)

    Kent, M.S.; Saunders, R.

    1997-02-18

    Coupling agents are disclosed based on functionalized block copolymers for bonding thermoset polymers to solid materials. These are polymers which possess at least two types of functional groups, one which is able to attach to and react with solid surfaces, and another which can react with a thermoset resin, which are incorporated as pendant groups in monomers distributed in blocks (typically two) along the backbone of the chain. The block copolymers in this invention are synthesized by living ring-opening metathesis polymerization. 18 figs.

  10. On new exact conformal blocks and Nekrasov functions

    CERN Document Server

    Nemkov, Nikita

    2016-01-01

    Recently, an intriguing family of the one-point toric conformal blocks AGT related to the $\\mathcal{N}=2^*\\,\\, SU(2)$ Nekrasov functions was discovered by M. Beccaria and G. Macorini. Members of the family are distinguished by having only finite amount of poles as functions of the intermediate dimension/v.e.v. in gauge theory. Another remarkable property is that these conformal blocks/Nekrasov functions can be found in closed form to all orders in the coupling expansion. Here we use Zamolodchikov's recurrence equation to systematically account for these exceptional conformal blocks. We conjecture that the family is infinite-dimensional and describe the corresponding parameter set.

  11. Modification of poly(styrene-block-butadiene-block-styrene) [SBS] with phosphorus containing fire retardants

    DEFF Research Database (Denmark)

    Chernyy, Sergey; Ullah, Saif; Jomaas, Grunde;

    2015-01-01

    application of the H3PO4 modified SBS as a fire retardant additive for bitumen material, in combination with synergetic melamine species, offered 25% better self-extinguishing properties of such formulation already at a low loading level of the fire retardant components (3.5 wt.%).......An elaborate survey of the chemical modification methods for endowing highly flammable SBS with increased fire resistant properties by means of chemical modification of the polymer backbone with phosphorus containing fire retardant species is presented. Optimal conditions for free radical addition...... of the Psingle bondH containing fire retardants to a double bonds of poly(butadiene) block of SBS were found, affording varied degree of the modification (0.2–21 mol%). Alternatively, a two-step procedure based on an epoxidation step followed by hydrolysis of the epoxides with phosphoric acid was developed...

  12. Train-of-four fade during onset of neuromuscular block with nondepolarising neuromuscular blocking agents.

    Science.gov (United States)

    Gibson, F M; Mirakhur, R K

    1989-04-01

    Fade in the train-of-four (TOF) responses during onset of neuromuscular block was studied following administration of atracurium (225 or 450 micrograms/kg), vecuronium (40 or 80 micrograms/kg), pancuronium (60 or 120 micrograms/kg) and tubocurarine (450 micrograms/kg). TOF ratios were measured at approximate heights of T1 (first response in the TOF) of 75, 50 and 25%. Fade in TOF increased as the height of T1 decreased, with maximum fade being observed at T1 of 25%. The greatest difference between relaxants was observed at T1 of 25%, vecuronium showing the least fade and pancuronium, atracurium and tubocurarine showing increasing fade, in that order. The difference between atracurium and tubocurarine or between vecuronium and pancuronium was not significant, but the degree of TOF fade was significantly greater with atracurium and tubocurarine in comparison to vecuronium or pancuronium.

  13. Morphology-properties relationship on nanocomposite films based on poly(styrene-block-diene-block-styrene copolymers and silver nanoparticles

    Directory of Open Access Journals (Sweden)

    2011-02-01

    Full Text Available A comparative study on the self-assembled nanostructured morphology and the rheological and mechanical properties of four different triblock copolymers, based on poly(styrene-block-diene-block-styrene and poly(styrene-block-diene-block-styrene matrices, and of their respective nanocomposites with 1 wt% silver nanoparticles, is reported in this work. In order to obtain well-dispersed nanoparticles in the block copolymer matrix, dodecanethiol was used as surfactant, showing good affinity with both nanoparticles and the polystyrene phase of the matrices as predicted by the solubility parameters calculated based on Hoftyzer and Van Krevelen theory. The block copolymer with the highest PS content shows the highest tensile modulus and tensile strength, but also the smallest elongation at break. When silver nanoparticles treated with surfactant were added to the block copolymer matrices, each system studied shows higher mechanical properties due to the good dispersion and the good interface of Ag nanoparticles in the matrices. Furthermore, it has been shown that semiempirical models such as Guth and Gold equation and Halpin-Tsai model can be used to predict the tensile modulus of the analyzed nanocomposites.

  14. Ultrasound-guided truncal blocks: A new frontier in regional anaesthesia

    Directory of Open Access Journals (Sweden)

    Arunangshu Chakraborty

    2016-01-01

    Full Text Available The practice of regional anaesthesia is rapidly changing with the introduction of ultrasound into the working domain of the anaesthesiologist. New techniques are being pioneered. Among the recent techniques, notable are the truncal blocks, for example, the transversus abdominis plane block, rectus sheath block, hernia block and quadratus lumborum block in the abdomen and the pectoral nerves (Pecs block 1 and 2, serratus anterior plane block and intercostal nerve block. This narrative review covers the brief anatomical discourse along with technical description of the ultrasound-guided truncal blocks.

  15. Ultrasound-guided truncal blocks: A new frontier in regional anaesthesia

    Science.gov (United States)

    Chakraborty, Arunangshu; Khemka, Rakhi; Datta, Taniya

    2016-01-01

    The practice of regional anaesthesia is rapidly changing with the introduction of ultrasound into the working domain of the anaesthesiologist. New techniques are being pioneered. Among the recent techniques, notable are the truncal blocks, for example, the transversus abdominis plane block, rectus sheath block, hernia block and quadratus lumborum block in the abdomen and the pectoral nerves (Pecs) block 1 and 2, serratus anterior plane block and intercostal nerve block. This narrative review covers the brief anatomical discourse along with technical description of the ultrasound-guided truncal blocks. PMID:27761032

  16. Completely random measures for modelling block-structured sparse networks

    DEFF Research Database (Denmark)

    Herlau, Tue; Schmidt, Mikkel Nørgaard; Mørup, Morten

    2016-01-01

    Many statistical methods for network data parameterize the edge-probability by attributing latent traits to the vertices such as block structure and assume exchangeability in the sense of the Aldous-Hoover representation theorem. Empirical studies of networks indicate that many real-world network...... is not significantly more difficult to implement than existing approaches to block-modelling and performs well on real network datasets.......Many statistical methods for network data parameterize the edge-probability by attributing latent traits to the vertices such as block structure and assume exchangeability in the sense of the Aldous-Hoover representation theorem. Empirical studies of networks indicate that many real-world networks...... [2014] proposed the use of a different notion of exchangeability due to Kallenberg [2006] and obtained a network model which admits power-law behaviour while retaining desirable statistical properties, however this model does not capture latent vertex traits such as block-structure. In this work we re...

  17. Investigation of Ultrasonic Calibration using Steel Standard Reference Blocks

    Directory of Open Access Journals (Sweden)

    Mohamed Galal Sayed ALI

    2012-12-01

    Full Text Available The equipment used in standardization must be adjusted in order that both the receiver amplifier and video display are linear over the range of distance and flaw size to be used. The failure to do that would result in different block-to-block response ratios because of the measurements depending on the scope reading or attenuator setting. In this paper, using two sets of steel reference blocks (area-amplitude and distance-amplitude to modified method to verify the linearity of the system of instruments used in the ultrasonic inspection. This method depends on the response from reference blocks with different hole diameters at constant gain and ratio between the figures slope at different gains. The linearity of the ultrasonic instruments can be measured with high precision. The results can be used effectively for determining resolution and sensitivity capabilities.

  18. Nanopatterned articles produced using surface-reconstructed block copolymer films

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Thomas P.; Park, Soojin; Wang, Jia-Yu; Kim, Bokyung

    2016-06-07

    Nanopatterned surfaces are prepared by a method that includes forming a block copolymer film on a substrate, annealing and surface reconstructing the block copolymer film to create an array of cylindrical voids, depositing a metal on the surface-reconstructed block copolymer film, and heating the metal-coated block copolymer film to redistribute at least some of the metal into the cylindrical voids. When very thin metal layers and low heating temperatures are used, metal nanodots can be formed. When thicker metal layers and higher heating temperatures are used, the resulting metal structure includes nanoring-shaped voids. The nanopatterned surfaces can be transferred to the underlying substrates via etching, or used to prepare nanodot- or nanoring-decorated substrate surfaces.

  19. Permutation-based Homogeneous Block Content Authentication for Watermarking

    Directory of Open Access Journals (Sweden)

    S.Maruthuperumal

    2013-02-01

    Full Text Available In modern days, digital watermarking has become an admired technique for hitting data in digital images to help guard against copyright infringement. The proposed Permutation-based Homogeneous Block Content authentication (PHBC methods develop a secure and excellence strong watermarking algorithm that combines the reward of permutation-based Homogeneous block (PHB with that of significant and insignificant bit values with X0R encryption function using Max coefficient of least coordinate value for embedding the watermark. In the projected system uses the relationship between the permutation blocks to embed many data into Homogeneous blocks without causing solemn distortion to the watermarked image. The experimental results show that the projected system is very efficient in achieving perceptual invisibility with an increase in the Peak Signal to Noise Ratio (PSNR. Moreover, the projected system is robust to a variety of signal processing operations, such as image Cropping, Rotation, Resizing, Adding noise, Filtering , Blurring and Motion blurring.

  20. EnviroAtlas - Portland, ME - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, green space, wetland, and agriculture. Impervious is...

  1. Non-Perturbative Topological Strings And Conformal Blocks

    CERN Document Server

    Cheng, Miranda C N; Vafa, Cumrun

    2010-01-01

    We give a non-perturbative completion of a class of closed topological string theories in terms of building blocks of dual open strings. In the specific case where the open string is given by a matrix model these blocks correspond to a choice of integration contour. We then apply this definition to the AGT setup where the dual matrix model has logarithmic potential and is conjecturally equivalent to Liouville conformal field theory. By studying the natural contours of these matrix integrals and their monodromy properties, we propose a precise map between topological string blocks and Liouville conformal blocks. Remarkably, this description makes use of the light-cone diagrams of closed string field theory, where the critical points of the matrix potential correspond to string interaction points.

  2. Non-perturbative topological strings and conformal blocks

    Science.gov (United States)

    Cheng, Miranda C. N.; Dijkgraaf, Robbert; Vafa, Cumrun

    2011-09-01

    We give a non-perturbative completion of a class of closed topological string theories in terms of building blocks of dual open strings. In the specific case where the open string is given by a matrix model these blocks correspond to a choice of integration contour. We then apply this definition to the AGT setup where the dual matrix model has logarithmic potential and is conjecturally equivalent to Liouville conformal field theory. By studying the natural contours of these matrix integrals and their monodromy properties, we propose a precise map between topological string blocks and Liouville conformal blocks. Remarkably, this description makes use of the light-cone diagrams of closed string field theory, where the critical points of the matrix potential correspond to string interaction points.

  3. EnviroAtlas - Cleveland, OH - Park Access by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset shows the block group population that is within and beyond an easy walking distance (500m) of a park entrance. Park entrances were included...

  4. EnviroAtlas - Portland, OR - Park Access by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset shows the block group population that is within and beyond an easy walking distance (500m) of a park entrance. Park entrances were included...

  5. Pressure versus current scaling in a blocked bore rail gun

    Science.gov (United States)

    Barrett, B. D.; Eubank, Eric; Nunnally, W. C.

    1993-07-01

    The paper presents experimental results from a blocked bore plasma armature rail gun. A piezoelectric transducer mounted in the bore blocking structure recorded time-resolved pressures over a range of input currents from 50 to 150 kA. The bore block is located at four positions where peak current occurs for the four respective charging voltages to power the system. Problems associated with obtaining these measurements and the solutions employed are discussed. Average distances from the block face to the armature current centroid are estimated assuming a pressure balance between the magnetic and neutral pressures. The averages of the measured pressures were found to be proportional to the input current raised to the power of 1.655.

  6. EnviroAtlas - Durham, NC - Park Access by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset shows the block group population that is within and beyond an easy walking distance (500m) of a park entrance. Park entrances were included...

  7. EnviroAtlas - Phoenix, AZ - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset presents environmental benefits of the urban forest in 2,434 block groups in Phoenix, Arizona. Carbon attributes, pollution removal and value, and...

  8. EnviroAtlas - Pittsburgh, PA - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 1,089 block groups in Pittsburgh, Pennsylvania. Carbon attributes, temperature...

  9. ARC Code TI: Block-GP: Scalable Gaussian Process Regression

    Data.gov (United States)

    National Aeronautics and Space Administration — Block GP is a Gaussian Process regression framework for multimodal data, that can be an order of magnitude more scalable than existing state-of-the-art nonlinear...

  10. EnviroAtlas - Pittsburgh, PA - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, and green space. Forest is combination of trees and...

  11. Climate Prediction Center (CPC) Northern and Southern Hemisphere Blocking Index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Atmospheric blocking is commonly referred to as the situation when the normal zonal flow is interrupted by strong and persistent meridional flow. The normal eastward...

  12. Split radius-form blocks for tube benders

    Science.gov (United States)

    Lange, D. R.; Seiple, C. W.

    1970-01-01

    Two-piece, radius-form block permits accurate forming and removing of parts with more than a 180 degree bend. Tube bender can shape flexible metal tubing in applications dealing with plumbing, heating, and pressure transmission lines.

  13. Block Hadamard measurement matrix with arbitrary dimension in compressed sensing

    Science.gov (United States)

    Liu, Shaoqiang; Yan, Xiaoyan; Fan, Xiaoping; Li, Fei; Xu, Wen

    2017-01-01

    As Hadamard measurement matrix cannot be used for compressing signals with dimension of a non-integral power-of-2, this paper proposes a construction method of block Hadamard measurement matrix with arbitrary dimension. According to the dimension N of signals to be measured, firstly, construct a set of Hadamard sub matrixes with different dimensions and make the sum of these dimensions equals to N. Then, arrange the Hadamard sub matrixes in a certain order to form a block diagonal matrix. Finally, take the former M rows of the block diagonal matrix as the measurement matrix. The proposed measurement matrix which retains the orthogonality of Hadamard matrix and sparsity of block diagonal matrix has highly sparse structure, simple hardware implements and general applicability. Simulation results show that the performance of our measurement matrix is better than Gaussian matrix, Logistic chaotic matrix, and Toeplitz matrix.

  14. Installation of a modular building block photovoltaic concentrator array field

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, J.A.; Cass, D.C.; Broadbent, S.

    1985-06-01

    A building block array field nominally rated at 25 kW has been installed in Albuquerque, New Mexico. The building block is a single source electrical circuit of six center pedestal two-axis tracking arrays connected in parallel and having a nominal operating voltage of 420 volts DC. Each array contains 60 point-focusing Fresnel lens photovoltaic concentrator modules connected in series for a nominal power output of 4.2 kW per array. The structural design uses a center pedestal two-axis cantilevered support tube with a closed loop sun sensor electronic control system. A master control provides manual override of the array field. The installation was accomplished without difficulty and demonstrated the ease of turnkey building block installation. The costs of 1 MW size fields is estimated to be $6.99 per watt installed based on the building block installation.

  15. Numerical Analysis of a Blocking Mass Attenuating Wave Propagation

    Institute of Scientific and Technical Information of China (English)

    Xianzhong Wang; Xiongliang Yao; Qiangyong Wang; Shuai Lv

    2011-01-01

    Based on wave theory,blocking mass impeding propagation of flexural waves was analyzed with force excitation applied on a ship pedestal.The analysis model of a complex structure was developed by combining statistical energy analysis and the finite element method.Based on the hybrid FE-SEA method,the vibro-acoustic response of a complex structure was solved.Then,the sound radiation of a cylindrical shell model influenced by blocking mass was calculated in mid/high frequency.The result shows that blocking mass has an obvious effect on impeding propagation.The study provides a theoretical and experimental basis for application of the blocking mass to structure-borne sound propagation control.

  16. Content-dependent block noise reduction for mobile displays

    Science.gov (United States)

    Kim, Ga-Hee; Lee, Yoon-Gyoo; Kim, Han-Eol; Kim, Choon-Woo

    2012-01-01

    Number of pixels on mobile displays is rapidly increasing. Recently, mobile displays with more than one million pixels have been introduced into markets. However, most of multimedia contents to be displayed on mobile displays have much smaller pixel counts. For example, number of pixels for a T-DMB(terrestrial digital multimedia broadcasting) sequence is 320x240. When enlargement is applied to input sequence, perceived image quality would be degraded. Increase in visibility of block noise is one of the major reasons for image quality degradation on mobile displays. This paper presents a simple and computationally efficient method to reduce visibility of block noise on enlarged multimedia sequences. In proposed method, a simple low pass filtering is selectively applied to the pixels of block noises for reduction of block noise visibility as well as faithful reproduction of image details.

  17. PRODUCTION OF PAVING BLOCK AND KERB INCORPORATING BLASTFURNACE SLAG

    Directory of Open Access Journals (Sweden)

    İsa YÜKSEL

    2007-02-01

    Full Text Available This paper presents results of an experimental study about partial substitution of granulated blast-furnace slag (GBFS as fine aggregate in production of concrete paving blocks and kerbs. GBFS is replaced sand for different GBFS/sand ratios in concrete during production of kerb and paving block specimens. Some tests orienting towards strength and durability were applied on these specimens including control specimens that are produced with normal concrete. Then, the results of tested properties of GBFS-replaced specimens and control specimens were compared. GBFS decreases the compressive strength of paving blocks and kerbs according to the results. However, some durability properties which are more important than strength for these elements are improved with GBFS replacement. The most improved property was abrasion resistance. It is concluded that it is feasible to use GBFS in paving block and kerb production with an optimum replacement ratio for these specimens.

  18. BLOCKING ALGORITHM FOR CURRENT PROTECTION DURING INRUSH MAGNETIZATION CURRENT

    Directory of Open Access Journals (Sweden)

    F. A. Romaniuk

    2014-01-01

    Full Text Available The paper presents blocking algorithm for current protection during inrush process. The algorithm is based on the evaluation of the ratio of the positive sequence second harmonic current to the negative sequence first harmonic current.

  19. EnviroAtlas - Paterson, NJ - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, and green space. Forest is just trees and forest....

  20. EnviroAtlas - Portland, OR - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, and green space. Forest is combination of trees and...