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Sample records for standstill causing congestive

  1. Congestion phenomena caused by matching pennies in evolutionary games

    NASA Astrophysics Data System (ADS)

    Szabó, György; Szolnoki, Attila

    2015-03-01

    Evolutionary social dilemma games are extended by an additional matching-pennies game that modifies the collected payoffs. In a spatial version players are distributed on a square lattice and interact with their neighbors. First, we show that the matching-pennies game can be considered as the microscopic force of the Red Queen effect that breaks the detailed balance and induces eddies in the microscopic probability currents if the strategy update is analogous to the Glauber dynamics for the kinetic Ising models. The resulting loops in probability current breaks symmetry between the chessboardlike arrangements of strategies via a bottleneck effect occurring along the four-edge loops in the microscopic states. The impact of this congestion is analogous to the application of a staggered magnetic field in the Ising model; that is, the order-disorder critical transition is wiped out by noise. It is illustrated that the congestion induced symmetry breaking can be beneficial for the whole community within a certain region of parameters.

  2. Nationwide SIP Telephony Network Design to Prevent Congestion Caused by Disaster

    NASA Astrophysics Data System (ADS)

    Satoh, Daisuke; Ashitagawa, Kyoko

    We present a session initiation protocol (SIP) network design for a voice-over-IP network to prevent congestion caused by people calling friends and family after a disaster. The design increases the capacity of SIP servers in a network by using all of the SIP servers equally. It takes advantage of the fact that equipment for voice data packets is different from equipment for signaling packets in SIP networks. Furthermore, the design achieves simple routing on the basis of telephone numbers. We evaluated the performance of our design in preventing congestion through simulation. We showed that the proposed design has roughly 20 times more capacity, which is 57 times the normal load, than the conventional design if a disaster were to occur in Niigata Prefecture struck by the Chuetsu earthquake in 2004.

  3. Peripheral venous congestion causes time- and dose-dependent release of endothelin-1 in humans.

    PubMed

    Lin, Jeffrey; Chudasama, Neelesh; Hayashi, Yacki; Hawk, Christopher; Ramnauth, Sahadeo D; Wong, Ka Yuk; Harxhi, Ante; Onat, Duygu; Wakabayashi, Michiyori; Uriel, Nir; Jorde, Ulrich P; LeJemtel, Thierry H; Sabbah, Hani N; Demmer, Ryan T; Colombo, Paolo C

    2017-03-01

    Endothelin-1 (ET-1) is a pivotal mediator of vasoconstriction and inflammation in congestive states such as heart failure (HF) and chronic kidney disease (CKD). Whether peripheral venous congestion (VC) increases plasma ET-1 at pressures commonly seen in HF and CKD patients is unknown. We seek to characterize whether peripheral VC promotes time- and dose-dependent increases in plasma ET-1 and whether these changes are sustained after decongestion. We used a randomized, cross-over design in 20 healthy subjects (age 30 ± 7 years). To experimentally model VC, venous pressure was increased to either 15 or 30 mmHg (randomized at first visit) above baseline by inflating a cuff around the subject's dominant arm; the nondominant arm served as a noncongested control. We measured plasma ET-1 at baseline, after 20, 60 and 120 min of VC, and finally at 180 min (60 min after cuff release and decongestion). Plasma ET-1 progressively and significantly increased over 120 min in the congested arm relative to the control arm and to baseline values. This effect was dose-dependent: ET-1 increased by 45% and 100% at VC doses of 15 and 30 mmHg, respectively (P < 0.05), and declined after 60 min of decongestion though remaining significantly elevated compared to baseline. In summary, peripheral VC causes time- and dose-dependent increases in plasma ET-1. Of note, the lower dose of 15 mmHg (more clinically relevant to HF and CKD patients) was sufficient to raise ET-1. These findings support the potentially contributory, not merely consequential, role of VC in the pathophysiology of HF and CKD.

  4. Venous Congestion, Endothelial and Neurohormonal Activation in Acute Decompensated Heart Failure: Cause or Effect?

    PubMed Central

    Colombo, Paolo C.; Doran, Amanda C.; Onat, Duygu; Wong, Ka Yuk; Ahmad, Myra; Sabbah, Hani N.; Demmer, Ryan T.

    2015-01-01

    Venous congestion and endothelial and neurohormonal activation are known to occur in acute decompensated heart failure (ADHF), yet the temporal role of these processes in the pathophysiology of decompensation is not fully understood. Conventional wisdom presumes congestion to be a consequence of worsening cardiovascular function; however, the biomechanically driven effects of venous congestion are biologically plausible contributors to ADHF that remain largely unexplored in vivo. Recent experimental evidence from human models suggests that fluid accumulation and venous congestion are not simply consequences of poor cardiovascular function, but rather are fundamental pro-oxidant, pro-inflammatory, and hemodynamic stimuli that contribute to acute decompensation. The latest advances in the monitoring of volume status using implantable devices allow for the detection of venous congestion before symptoms arise. This may ultimately lead to improved treatment strategies including not only diuretics, but also specific, adjuvant interventions to counteract endothelial and neurohormonal activation during early preclinical decompensation. PMID:25740404

  5. Heart rate turbulence predicts all-cause mortality and sudden death in congestive heart failure patients.

    PubMed

    Cygankiewicz, Iwona; Zareba, Wojciech; Vazquez, Rafael; Vallverdu, Montserrat; Gonzalez-Juanatey, Jose R; Valdes, Mariano; Almendral, Jesus; Cinca, Juan; Caminal, Pere; de Luna, Antoni Bayes

    2008-08-01

    Abnormal heart rate turbulence (HRT) has been documented as a strong predictor of total mortality and sudden death in postinfarction patients, but data in patients with congestive heart failure (CHF) are limited. The aim of this study was to evaluate the prognostic significance of HRT for predicting mortality in CHF patients in New York Heart Association (NYHA) class II-III. In 651 CHF patients with sinus rhythm enrolled into the MUSIC (Muerte Subita en Insuficiencia Cardiaca) study, the standard HRT parameters turbulence onset (TO) and slope (TS), as well as HRT categories, were assessed for predicting total mortality and sudden death. HRT was analyzable in 607 patients, mean age 63 years (434 male), 50% of ischemic etiology. During a median follow up of 44 months, 129 patients died, 52 from sudden death. Abnormal TS and HRT category 2 (HRT2) were independently associated with increased all-cause mortality (HR: 2.10, CI: 1.41 to 3.12, P <.001 and HR: 2.52, CI: 1.56 to 4.05, P <.001; respectively), sudden death (HR: 2.25, CI: 1.13 to 4.46, P = .021 for HRT2), and death due to heart failure progression (HR: 4.11, CI: 1.84 to 9.19, P <.001 for HRT2) after adjustment for clinical covariates in multivariate analysis. The prognostic value of TS for predicting total mortality was similar in various groups dichotomized by age, gender, NYHA class, left ventricular ejection fraction, and CHF etiology. TS was found to be predictive for total mortality only in patients with QRS > 120 ms. HRT is a potent risk predictor for both heart failure and arrhythmic death in patients with class II and III CHF.

  6. Does Expansion Cause Congestion? The Case of the Older British Universities, 1994-2004

    ERIC Educational Resources Information Center

    Flegg, A. T.; Allen, D. O.

    2007-01-01

    This paper examines whether the rapid growth in the number of students in British universities in recent years has led to congestion, in the sense that certain universities' output could have been higher if this expansion had been less rapid. The focus of the paper is on 45 older universities that were in existence prior to 1992. The analysis…

  7. Hyperthyroidism as a reversible cause of right ventricular overload and congestive heart failure

    PubMed Central

    Di Giovambattista, Raniero

    2008-01-01

    We describe a case of severe congestive heart failure and right ventricular overload associated with overt hyperthyroidism, completely reversed with antithyroid therapy in a few week. It represents a very unusual presentation of overt hyperthyroidism because of the severity of right heart failure. The impressive right ventricular volume overload made mandatory to perform transesophageal echo and angio-TC examination to exclude the coexistence of ASD or anomalous pulmonary venous return. Only a few cases of reversible right heart failure, with or without pulmonary hypertension, have been reported worldwide. In our case the most striking feature has been the normalization of the cardiovascular findings after six weeks of tiamazole therapy. PMID:18549503

  8. [Congestive heart failure caused by the thyroid stimulating hormone(TSH) secreting pituitary adenoma: report of two cases].

    PubMed

    Fujita, K; Yanaka, K; Tomono, Y; Kamezaki, T; Kujiraoka, Y; Nose, T

    2001-08-01

    A 42-year-old man and a 31-year-old man with congestive heart failure caused by the thyroid stimulating hormone(TSH) secreting pituitary adenoma were reported. Heart failure was improved after transsphenoidal resection of the pituitary adenoma in each patient. The syndrome of inappropriate secretion of TSH causes hyperthyroidism. Thyroid hormone acts directly on cardiac muscle to increase the stroke volume. Hyperthyroidism itself reduces the peripheral vascular resistance and an elevated basal metabolism which is the basic physiologic change in hyperthyroidism dilates small vessels and reduces vascular resistance. The reduced vascular resistance contributes to increase stroke volume. Thyroid hormone also acts directly on the cardiac pacemakers to be apt to cause tachycardiac atrial fibrillation. These mechanical changes in hyperthyroidism increase not only the cardiac output but also the venous return. The increased blood volume and the shortened ventricular filling time due to tachycardia result in congestive heart failure. TSH secreting pituitary adenoma is a rare tumor, however heart failure is common disease. TSH secreting pituitary adenoma should be taken into consideration in patients with heart failure. The presented cases were very enlightening to understand the relation between brain tumor and heart disease.

  9. Return of Viable Cardiac Function After Sonographic Cardiac Standstill in Pediatric Cardiac Arrest.

    PubMed

    Steffen, Katherine; Thompson, W Reid; Pustavoitau, Aliaksei; Su, Erik

    2017-01-01

    Sonographic cardiac standstill during adult cardiac arrest is associated with failure to get return to spontaneous circulation. This report documents 3 children whose cardiac function returned after standstill with extracorporeal membranous oxygenation. Sonographic cardiac standstill may not predict cardiac death in children.

  10. Effect of pimobendan on case fatality rate in Doberman Pinschers with congestive heart failure caused by dilated cardiomyopathy.

    PubMed

    O'Grady, M R; Minors, S L; O'Sullivan, M L; Horne, R

    2008-01-01

    Despite traditional therapy of a diuretic, angiotensin converting enzyme inhibitor, digoxin, or a combination of these drugs, survival of dogs with dilated cardiomyopathy (DCM) is low. Pimobendan, an inodilator, has both inotropic and balanced peripheral vasodilatory properties. Pimobendan when added to conventional therapy will improve morbidity and reduce case fatality rate in Doberman Pinschers with congestive heart failure (CHF) caused by DCM. Sixteen Doberman Pinschers in CHF caused by DCM. A prospective randomized, double-blind, placebo-controlled study with treatment failure as the primary and quality of life (QoL) indices as secondary outcome variables. Therapy consisted of furosemide (per os [PO] as required) and benazepril hydrochloride (0.5 mg/kg PO q12h) and dogs were randomized in pairs and by sex to receive pimobendan (0.25 mg/kg PO q12h) or placebo (1 tablet PO q12h). Pimobendan-treated dogs had a significant improvement in time to treatment failure (pimobendan median, 130.5 days; placebo median, 14 days; P= .002; risk ratio = 0.35, P= .003, lower 5% confidence limit = 0.13, upper 95% confidence limit = 0.71). Number and rate of dogs reaching treatment failure in the placebo group precluded the analysis of QoL. Pimobendan should be used as a first-line therapeutic in Doberman Pinschers for the treatment of CHF caused by DCM.

  11. [A rare cause of 2:1 atrioventricular block and congestive heart failure in preterm infants: Hypocalcemia].

    PubMed

    Azak, Emine; Tatar Aksoy, Hatice; Ünsal, Handan; Çetin, İbrahim İlker

    2017-01-01

    Atrioventricular (AV) block in the neonatal period is a rare disorder. It is frequently associated with underlying structural congenital heart disease and maternal lupus. Presently described is premature baby who developed 2:1 AV block and congestive heart failure due to hypocalcemia. Dramatic clinical improvement was observed following treatment of intravenous 10% calcium gluconate. Therefore, it is suggested that serum calcium level of newborns with AV block and congestive heart failure be measured.

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

    PubMed

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

    2009-01-21

    understanding of the mechanical implications of congestive heart failure (CHF) caused by BBB.

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

    NASA Astrophysics Data System (ADS)

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

    2009-01-01

    understanding of the mechanical implications of congestive heart failure (CHF) caused by BBB.

  14. Pathophysiology of nasal congestion

    PubMed Central

    Naclerio, Robert M; Bachert, Claus; Baraniuk, James N

    2010-01-01

    Nasal congestion is a common symptom in rhinitis (both allergic and nonallergic), rhinosinusitis and nasal polyposis. Congestion can also be caused by physical obstruction of nasal passages and/or modulation of sensory perception. Mucosal inflammation underlies many of the specific and interrelated factors that contribute to nasal congestion, as well as other symptoms of both allergic rhinitis and rhinosinusitis. A wide range of biologically active agents (eg, histamine, tumor necrosis factor-α, interleukins, cell adhesion molecules) and cell types contribute to inflammation, which can manifest as venous engorgement, increased nasal secretions and tissue swelling/edema, ultimately leading to impaired airflow and the sensation of nasal congestion. Inflammation-induced changes in the properties of sensory afferents (eg, expression of peptides and receptors) that innervate the nose can also contribute to altered sensory perception, which may result in a subjective feeling of congestion. Increased understanding of the mechanisms underlying inflammation can facilitate improved treatment selection and the development of new therapies for congestion. PMID:20463823

  15. Thiamine-responsive megaloblastic anemia syndrome with atrial standstill: a case report.

    PubMed

    Aycan, Zehra; Baş, Veysel Nijat; Cetinkaya, Semra; Ağladioğlu, Sebahat Yilmaz; Kendirci, Havva Nur Peltek; Senocak, Filiz

    2011-03-01

    Thiamine-responsive megaloblastic anemia (TRMA) syndrome is an uncommon autosomal recessive disorder. The disease is caused by mutations in the gene, SLC19A2, encoding a high-affinity thiamine transporter, which disturbs the active thiamine uptake into cells. Major features include megaloblastic anemia, diabetes mellitus, and sensorineural deafness. Cardiac malformations with conduction defects and/or dysrhythmias, have also been described in some patients. To our knowledge, only 13 TRMA patients with cardiac defects have been reported. Here, we describe the first case of TRMA syndrome with atrial standstill, probably caused by a 2 base-pair deletion in exon 4 (1147delGT) of the gene SLC19A2.

  16. Survival of 4 dogs with persistent atrial standstill treated by pacemaker implantation.

    PubMed

    Thomason, Justin D; Kraus, Marc S; Fallaw, Tiffany L; Calvert, Clay A

    2016-03-01

    Pacemakers were implanted in 4 client-owned female dogs which had persistent atrial standstill. Three dogs were alive after 14 to 39 months and 1 dog was euthanized after 10.5 years. This report demonstrates that some dogs with persistent atrial standstill can survive for extended time periods.

  17. What is a lunar standstill? Problems of accuracy and validity in the Thom Paradigm

    NASA Astrophysics Data System (ADS)

    Sims, L.

    North West European late Neolithic and Early Bronze Age (EBA) monumental alignments on the sun's solstices and the moon's standstills were first systematically studied by Thom (Thom 1971). Later research, since labelled 'the Thom paradigm' (Ruggles 1999), has rejected Thom's eclipse prediction and calendrical theories for these ancient alignments, yet retained his definition of a lunar standstill as the 'geocentric extreme declination' of the moon (Heggie 1981a, Heggie 1981b, Hoskin 2001, Morrison 1980, North 1996, Ruggles 1999, Thom 1971). Thom suggested that prehistoric 'extrapolation devices' calculated this mid-transit property of the moon from observed horizon alignments, but subsequent research has found no evidence for such devices. While a mid-transit definition of a lunar standstill is an accurate specification of the phenomena, it is based upon the premises of modern heliocentric astronomy and is unlikely to provide valid interpretations of the monument builder's use of horizon 'astronomy'. This paper attempts to demonstrate that the current theories used to explain the late Neolithic/EBA function of lunar standstill alignments do not fit the horizon, and therefore megalithic user, properties of lunar standstills. It is argued that a recent model (Sims 2006b) is more consistent with the archaeology and 'astronomy' of horizon-aligned monuments, and with any ethnographic elaboration of the Thom paradigm.

  18. Congestion and decongestion in a communication network.

    PubMed

    Singh, Brajendra K; Gupte, Neelima

    2005-05-01

    We study network traffic dynamics in a two-dimensional communication network with regular nodes and hubs. If the network experiences heavy message traffic, congestion occurs due to the finite capacity of the nodes. We discuss strategies to manipulate hub capacity and hub connections to relieve congestion and define a coefficient of betweenness centrality (CBC), a direct measure of network traffic, which is useful for identifying hubs that are most likely to cause congestion. The addition of assortative connections to hubs of high CBC relieves congestion very efficiently.

  19. Congestive heart failure caused by transvenous pacemaker lead prolapse and associated right ventricular outflow tract obstruction in a dog.

    PubMed

    Djani, D M; Coleman, A E; Rapoport, G S; Schmiedt, C W; Layher, J; Thomason, J D

    2016-12-01

    A 16-year-old dog was presented for cough as well as increased respiratory rate and effort three years after implantation of a single-lead transvenous artificial pacemaker system. Thoracic radiographs and echocardiography disclosed prolapse of the pacemaker lead into the main pulmonary artery, causing severe pulmonary insufficiency and right-sided volume overload. Repositioning of the pacemaker lead led to improvement of pulmonary insufficiency and resolution of the dog's clinical signs and cavitary effusions. This case describes a late complication of pacemaker implantation that may be avoided by appropriate use of the manufacturer-provided anchoring sleeve and avoidance of excessive lead redundancy. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Survival and echocardiographic data in dogs with congestive heart failure caused by mitral valve disease and treated by multiple drugs: a retrospective study of 21 cases.

    PubMed

    de Madron, Eric; King, Jonathan N; Strehlau, Günther; White, Regina Valle

    2011-11-01

    This retrospective study reports the survival time [onset of congestive heart failure (CHF) to death from any cause] of 21 dogs with mitral regurgitation (MR) and CHF treated with a combination of furosemide, angiotensin-converting enzyme inhibitor (ACEI, benazepril, or enalapril), pimobendan, spironolactone, and amlodipine. Baseline echocardiographic data: end-systolic and end-diastolic volume indices (ESVI and EDVI), left atrium to aorta ratio (LA/Ao), and regurgitant fraction (RF) are reported. Median survival time (MST) was 430 d. Initial dosage of furosemide (P = 0.0081) and LA/Ao (P = 0.042) were negatively associated with survival. Baseline echocardiographic indices (mean ± standard deviation) were 40.24 ± 16.76 for ESVI, 161.48 ± 44.49 mL/m(2) for EDVI, 2.11 ± 0.75 for LA/Ao, and 64.71 ± 16.85% for RF. Combining furosemide, ACEI, pimobendan, spironolactone, and amlodipine may result in long survival times in dogs with MR and CHF. Severity of MR at onset of CHF is at least moderate.

  1. Permanent transvenous pacemaker implantation in an Ibizan hound cross with persistent atrial standstill

    PubMed Central

    MacAulay, Kevin

    2002-01-01

    An Ibizan hound cross was referred with a 1-year history of syncope and exercise intolerance. An electrocardiogram showed bradycardia and no P waves; atrial standstill was diagnosed. A permanent artificial endocardial pacemaker was implanted. The lead dislodged and was reimplanted into the right ventricular apex. Capture was once again achieved. PMID:12395764

  2. Efficacy of Precordial Percussion Pacing Assessed in a Cardiac Standstill Microminipig Model.

    PubMed

    Wada, Takeshi; Ohara, Hiroshi; Nakamura, Yuji; Cao, Xin; Izumi-Nakaseko, Hiroko; Ando, Kentaro; Honda, Mitsuru; Yoshihara, Katsunori; Nakazato, Yuji; Lurie, Keith G; Sugiyama, Atsushi

    2017-07-25

    Potential cardiovascular benefits of precordial percussion pacing (PPP) during cardiac standstill are unknown.Methods and Results:A cardiac standstill model in amicrominipigwas created by inducing complete atrioventricular block with a catheter ablation technique (n=7). Next, the efficacy of cardiopulmonary resuscitation by standard chest compressions (S-CPR), PPP and ventricular electrical pacing in this model were analyzed in series (n=4). To assess the mechanism of PPP, a non-selective, stretch-activated channel blocker, amiloride, was administered during PPP (n=3). Peak systolic and diastolic arterial pressures during S-CPR, PPP and ventricular electrical pacing were statistically similar. However, the duration of developed arterial pressure with PPP was comparable to that with ventricular electrical pacing, and significantly greater than that with S-CPR. Amiloride decreased the induction rate of ventricular electrical activity by PPP in a dose-related manner. Each animal survived without any neurological deficit at 24, 48 h and 1 week, even with up to 2 h of continuous PPP. In amicrominipigmodel of cardiac standstill, PPP can become a novel means to significantly improve physiological outcomes after cardiac standstill or symptomatic bradyarrhythmias in the absence of cardiac pacing. Activation of the non-selective stretch-activated channels may mediate some of the mechanophysiological effects of PPP. Further study of PPP by itself and together with S-CPR is warranted using cardiac arrest models of atrioventricular block and asystole.

  3. Market Mechanism for Line Congestion Clearance

    NASA Astrophysics Data System (ADS)

    Ruiz Monroy, José Joaquín; Kita, Hiroyuki; Tanaka, Eiichi; Hasegawa, Jun

    This paper proposes a mechanism for clearance of line congestion and power flow control in a deregulated market environment. The mechanism applies penalties to the bilateral transactions that cause line congestion by increasing the prices of such transactions. The market regulates itself by redefining the transactions and checking again for violations, applying penalties if necessary and repeating the process until all the demand is satisfied without causing line congestion to the system. A bilateral transaction matrix (BTM) creation algorithm developed by the authors and a DC power flow program are integrated as parts of the market mechanism proposed in this paper. The congestion is cleared by the market participants when they reschedule their transactions. This mechanism is useful to study the effects of bilateral transactions on a power system and helps the Independent System Operator (ISO) to create rules and market mechanisms for line congestion clearance and power flow control.

  4. Influence of Androgen Deprivation Therapy on All-Cause Mortality in Men With High-Risk Prostate Cancer and a History of Congestive Heart Failure or Myocardial Infarction

    SciTech Connect

    Nguyen, Paul L.; Chen, Ming-Hui; Beckman, Joshua A.; Beard, Clair J.; Martin, Neil E.; Choueiri, Toni K.; Hu, Jim C.; Dosoretz, Daniel E.; Moran, Brian J.; Salenius, Sharon A.; Braccioforte, Michelle H.; Kantoff, Philip W.; D'Amico, Anthony V.; Ennis, Ronald D.

    2012-03-15

    Purpose: It is unknown whether the excess risk of all-cause mortality (ACM) observed when androgen deprivation therapy (ADT) is added to radiation for men with prostate cancer and a history of congestive heart failure (CHF) or myocardial infarction (MI) also applies to those with high-risk disease. Methods and Materials: Of 14,594 men with cT1c-T3aN0M0 prostate cancer treated with brachytherapy-based radiation from 1991 through 2006, 1,378 (9.4%) with a history of CHF or MI comprised the study cohort. Of these, 22.6% received supplemental external beam radiation, and 42.9% received a median of 4 months of neoadjuvant ADT. Median age was 71.8 years. Median follow-up was 4.3 years. Cox multivariable analysis tested for an association between ADT use and ACM within risk groups, after adjusting for treatment factors, prognostic factors, and propensity score for ADT. Results: ADT was associated with significantly increased ACM (adjusted hazard ratio [AHR] = 1.76; 95% confidence interval [CI], 1.32-2.34; p = 0.0001), with 5-year estimates of 22.71% with ADT and 11.62% without ADT. The impact of ADT on ACM by risk group was as follows: high-risk AHR = 2.57; 95% CI, 1.17-5.67; p = 0.019; intermediate-risk AHR = 1.75; 95% CI, 1.13-2.73; p = 0.012; low-risk AHR = 1.52; 95% CI, 0.96-2.43; p = 0.075). Conclusions: Among patients with a history of CHF or MI treated with brachytherapy-based radiation, ADT was associated with increased all-cause mortality, even for patients with high-risk disease. Although ADT has been shown in Phase III studies to improve overall survival in high-risk disease, the small subgroup of high-risk patients with a history of CHF or MI, who represented about 9% of the patients, may be harmed by ADT.

  5. Treatment of congestion in upper respiratory diseases

    PubMed Central

    Meltzer, Eli O; Caballero, Fernan; Fromer, Leonard M; Krouse, John H; Scadding, Glenis

    2010-01-01

    Congestion, as a symptom of upper respiratory tract diseases including seasonal and perennial allergic rhinitis, acute and chronic rhinosinusitis, and nasal polyposis, is principally caused by mucosal inflammation. Though effective pharmacotherapy options exist, no agent is universally efficacious; therapeutic decisions must account for individual patient preferences. Oral H1-antihistamines, though effective for the common symptoms of allergic rhinitis, have modest decongestant action, as do leukotriene receptor antagonists. Intranasal antihistamines appear to improve congestion better than oral forms. Topical decongestants reduce congestion associated with allergic rhinitis, but local adverse effects make them unsuitable for long-term use. Oral decongestants show some efficacy against congestion in allergic rhinitis and the common cold, and can be combined with oral antihistamines. Intranasal corticosteroids have broad anti-inflammatory activities, are the most potent long-term pharmacologic treatment of congestion associated with allergic rhinitis, and show some congestion relief in rhinosinusitis and nasal polyposis. Immunotherapy and surgery may be used in some cases refractory to pharmacotherapy. Steps in congestion management include (1) diagnosis of the cause(s), (2) patient education and monitoring, (3) avoidance of environmental triggers where possible, (4) pharmacotherapy, and (5) immunotherapy (for patients with allergic rhinitis) or surgery for patients whose condition is otherwise uncontrolled. PMID:20463825

  6. Focus on renal congestion in heart failure.

    PubMed

    Afsar, Baris; Ortiz, Alberto; Covic, Adrian; Solak, Yalcin; Goldsmith, David; Kanbay, Mehmet

    2016-02-01

    Hospitalizations due to heart failure are increasing steadily despite advances in medicine. Patients hospitalized for worsening heart failure have high mortality in hospital and within the months following discharge. Kidney dysfunction is associated with adverse outcomes in heart failure patients. Recent evidence suggests that both deterioration in kidney function and renal congestion are important prognostic factors in heart failure. Kidney congestion in heart failure results from low cardiac output (forward failure), tubuloglomerular feedback, increased intra-abdominal pressure or increased venous pressure. Regardless of the cause, renal congestion is associated with increased morbidity and mortality in heart failure. The impact on outcomes of renal decongestion strategies that do not compromise renal function should be explored in heart failure. These studies require novel diagnostic markers that identify early renal damage and renal congestion and allow monitoring of treatment responses in order to avoid severe worsening of renal function. In addition, there is an unmet need regarding evidence-based therapeutic management of renal congestion and worsening renal function. In the present review, we summarize the mechanisms, diagnosis, outcomes, prognostic markers and treatment options of renal congestion in heart failure.

  7. Focus on renal congestion in heart failure

    PubMed Central

    Afsar, Baris; Ortiz, Alberto; Covic, Adrian; Solak, Yalcin; Goldsmith, David; Kanbay, Mehmet

    2016-01-01

    Hospitalizations due to heart failure are increasing steadily despite advances in medicine. Patients hospitalized for worsening heart failure have high mortality in hospital and within the months following discharge. Kidney dysfunction is associated with adverse outcomes in heart failure patients. Recent evidence suggests that both deterioration in kidney function and renal congestion are important prognostic factors in heart failure. Kidney congestion in heart failure results from low cardiac output (forward failure), tubuloglomerular feedback, increased intra-abdominal pressure or increased venous pressure. Regardless of the cause, renal congestion is associated with increased morbidity and mortality in heart failure. The impact on outcomes of renal decongestion strategies that do not compromise renal function should be explored in heart failure. These studies require novel diagnostic markers that identify early renal damage and renal congestion and allow monitoring of treatment responses in order to avoid severe worsening of renal function. In addition, there is an unmet need regarding evidence-based therapeutic management of renal congestion and worsening renal function. In the present review, we summarize the mechanisms, diagnosis, outcomes, prognostic markers and treatment options of renal congestion in heart failure. PMID:26798459

  8. Making the Traffic Operations Case for Congestion Pricing: Operational Impacts of Congestion Pricing

    SciTech Connect

    Chin, Shih-Miao; Hu, Patricia S; Davidson, Diane

    2011-02-01

    Congestion begins when an excess of vehicles on a segment of roadway at a given time, resulting in speeds that are significantly slower than normal or 'free flow' speeds. Congestion often means stop-and-go traffic. The transition occurs when vehicle density (the number of vehicles per mile in a lane) exceeds a critical level. Once traffic enters a state of congestion, recovery or time to return to a free-flow state is lengthy; and during the recovery process, delay continues to accumulate. The breakdown in speed and flow greatly impedes the efficient operation of the freeway system, resulting in economic, mobility, environmental and safety problems. Freeways are designed to function as access-controlled highways characterized by uninterrupted traffic flow so references to freeway performance relate primarily to the quality of traffic flow or traffic conditions as experienced by users of the freeway. The maximum flow or capacity of a freeway segment is reached while traffic is moving freely. As a result, freeways are most productive when they carry capacity flows at 60 mph, whereas lower speeds impose freeway delay, resulting in bottlenecks. Bottlenecks may be caused by physical disruptions, such as a reduced number of lanes, a change in grade, or an on-ramp with a short merge lane. This type of bottleneck occurs on a predictable or 'recurrent' basis at the same time of day and same day of week. Recurrent congestion totals 45% of congestion and is primarily from bottlenecks (40%) as well as inadequate signal timing (5%). Nonrecurring bottlenecks result from crashes, work zone disruptions, adverse weather conditions, and special events that create surges in demand and that account for over 55% of experienced congestion. Figure 1.1 shows that nonrecurring congestion is composed of traffic incidents (25%), severe weather (15%), work zones, (10%), and special events (5%). Between 1995 and 2005, the average percentage change in increased peak traveler delay, based on

  9. Autonomous Congestion Control in Delay-Tolerant Networks

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott; Jennings, Esther; Schoolcraft, Joshua

    2006-01-01

    Congestion control is an important feature that directly affects network performance. Network congestion may cause loss of data or long delays. Although this problem has been studied extensively in the Internet, the solutions for Internet congestion control do not apply readily to challenged network environments such as Delay Tolerant Networks (DTN) where end-to-end connectivity may not exist continuously and latency can be high. In DTN, end-to-end rate control is not feasible. This calls for congestion control mechanisms where the decisions can be made autonomously with local information only. We use an economic pricing model and propose a rule-based congestion control mechanism where each router can autonomously decide on whether to accept a bundle (data) based on local information such as available storage and the value and risk of accepting the bundle (derived from historical statistics). Preliminary experimental results show that this congestion control mechanism can protect routers from resource depletion without loss of data.

  10. Autonomous Congestion Control in Delay-Tolerant Networks

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott; Jennings, Esther; Schoolcraft, Joshua

    2006-01-01

    Congestion control is an important feature that directly affects network performance. Network congestion may cause loss of data or long delays. Although this problem has been studied extensively in the Internet, the solutions for Internet congestion control do not apply readily to challenged network environments such as Delay Tolerant Networks (DTN) where end-to-end connectivity may not exist continuously and latency can be high. In DTN, end-to-end rate control is not feasible. This calls for congestion control mechanisms where the decisions can be made autonomously with local information only. We use an economic pricing model and propose a rule-based congestion control mechanism where each router can autonomously decide on whether to accept a bundle (data) based on local information such as available storage and the value and risk of accepting the bundle (derived from historical statistics). Preliminary experimental results show that this congestion control mechanism can protect routers from resource depletion without loss of data.

  11. Advanced Congestive Heart Failure Associated With Disseminated Intravascular Coagulopathy.

    PubMed

    Sarcon, Annahita; Liu, Xiaoli; Ton, David; Haywood, James; Hitchcock, Todd

    2015-01-01

    Background. Disseminated intravascular coagulopathy (DIC) is a complication of an underlying disease and not a primary illness. It is most commonly associated with sepsis, trauma, obstetrical complications, and malignancies. There are very few cases in the literature illustrating the association between DIC and congestive heart failure. Findings. In this report, we present a case of severe congestive heart failure, leading to biventricular thrombi and subsequently DIC. Conclusion. We suggest that the association between congestive heart failure and DIC is an underrecognized one. Congestive heart failure continues to remain a major cause of morbidity and mortality despite advances in medical therapies. Thus far, the precise role of coagulation factors in congestive heart failure is unknown. Further investigations are needed to elucidate the pathophysiology of congestive heart failure and coagulation factors.

  12. Simulating society transitions: standstill, collapse and growth in an evolving network model.

    PubMed

    Xu, Guanghua; Yang, Junjie; Li, Guoqing

    2013-01-01

    We developed a model society composed of various occupations that interact with each other and the environment, with the capability of simulating three widely recognized societal transition patterns: standstill, collapse and growth, which are important compositions of society evolving dynamics. Each occupation is equipped with a number of inhabitants that may randomly flow to other occupations, during which process new occupations may be created and then interact with existing ones. Total population of society is associated with productivity, which is determined by the structure and volume of the society. We ran the model under scenarios such as parasitism, environment fluctuation and invasion, which correspond to different driving forces of societal transition, and obtained reasonable simulation results. This work adds to our understanding of societal evolving dynamics as well as provides theoretical clues to sustainable development.

  13. Adult-onset nemaline myopathy in a dog presenting with persistent atrial standstill and primary hypothyroidism.

    PubMed

    Nakamura, R K; Russell, N J; Shelton, G D

    2012-06-01

    A nine-year-old neutered female mixed breed dog presented for evaluation following a five-day history of lethargy, inappetence, weakness, abdominal distension and generalised muscle atrophy. Persistent vatrial standstill with a junctional rhythm was identified on electrocardiogram. Echocardiogram identified moderate dilation of all cardiac chambers and mild thickening of the mitral and tricuspid valves. Serology was negative for Neospora caninum and Toxoplasma gondii. Permanent pacemaker implantation was performed in addition to endomyocardial and skeletal muscle biopsies. Cryosections from the biceps femoris muscle showed numerous nemaline rod bodies while endomyocardial biopsies were possibly consistent with end-stage myocarditis. Rod bodies have rarely been reported in the veterinary literature. To the authors' knowledge, this is the first report of adult-onset nemaline rod myopathy and hypothyroidism with concurrent cardiac disease in a dog. © 2012 British Small Animal Veterinary Association.

  14. The architectonic encoding of the minor lunar standstills in the horizon of the Giza pyramids.

    NASA Astrophysics Data System (ADS)

    Hossam, M. K. Aboulfotouh

    The paper is an attempt to show the architectonic method of the ancient Egyptian designers for encoding the horizontal-projections of the moon's declinations during two events of the minor lunar standstills, in the design of the site-plan of the horizon of the Giza pyramids, using the methods of descriptive geometry. It shows that the distance of the eastern side of the second Giza pyramid from the north-south axis of the great pyramid encodes a projection of a lunar declination, when earth's obliquity-angle was ~24.10°. Besides, it shows that the angle of inclination of the causeway of the second Giza pyramid, of ~13.54° south of the cardinal east, encodes the projection of another lunar declination when earth's obliquity-angle reaches ~22.986°. In addition, it shows the encoded coordinate system in the site-plan of the horizon of the Giza pyramids.

  15. Danish Passage Graves, "Spring/Summer/Fall full Moons" and Lunar Standstills

    NASA Astrophysics Data System (ADS)

    Clausen, Claus Jørgen

    2015-05-01

    The author proposes and discusses a model for azimuth distribution which involves the criterion of a 'spring full moon' (or a 'fall full moon') proposed by Marciano Da Silva (Da Silva 2004). The model is based on elements of the rising pattern of the summer full moon combined with directions pointing towards full moonrises which occur immediately prior to lunar standstill eclipses and directions aimed at the points at which these eclipses begin. An observed sample of 153 directions has been compared with the proposed model, which has been named the lunar 'season pointer'. Statistical tests show that the model fits well with the observed sample within the azimuth interval of 54.5° to 156.5°. The conclusion made is that at least the 'season pointer' section of the model used could very well explain the observed distribution.

  16. Simulating Society Transitions: Standstill, Collapse and Growth in an Evolving Network Model

    PubMed Central

    Xu, Guanghua; Yang, Junjie; Li, Guoqing

    2013-01-01

    We developed a model society composed of various occupations that interact with each other and the environment, with the capability of simulating three widely recognized societal transition patterns: standstill, collapse and growth, which are important compositions of society evolving dynamics. Each occupation is equipped with a number of inhabitants that may randomly flow to other occupations, during which process new occupations may be created and then interact with existing ones. Total population of society is associated with productivity, which is determined by the structure and volume of the society. We ran the model under scenarios such as parasitism, environment fluctuation and invasion, which correspond to different driving forces of societal transition, and obtained reasonable simulation results. This work adds to our understanding of societal evolving dynamics as well as provides theoretical clues to sustainable development. PMID:24086530

  17. A common framework for the analysis of complex motion? Standstill and capture illusions

    PubMed Central

    Dürsteler, Max R.

    2014-01-01

    A series of illusions was created by presenting stimuli, which consisted of two overlapping surfaces each defined by textures of independent visual features (i.e., modulation of luminance, color, depth, etc.). When presented concurrently with a stationary 2-D luminance texture, observers often fail to perceive the motion of an overlapping stereoscopically defined depth-texture. This illusory motion standstill arises due to a failure to represent two independent surfaces (one for luminance and one for depth textures) and motion transparency (the ability to perceive motion of both surfaces simultaneously). Instead the stimulus is represented as a single non-transparent surface taking on the stationary nature of the luminance-defined texture. By contrast, if it is the 2D-luminance defined texture that is in motion, observers often perceive the stationary depth texture as also moving. In this latter case, the failure to represent the motion transparency of the two textures gives rise to illusionary motion capture. Our past work demonstrated that the illusions of motion standstill and motion capture can occur for depth-textures that are rotating, or expanding / contracting, or else spiraling. Here I extend these findings to include stereo-shearing. More importantly, it is the motion (or lack thereof) of the luminance texture that determines how the motion of the depth will be perceived. This observation is strongly in favor of a single pathway for complex motion that operates on luminance-defines texture motion signals only. In addition, these complex motion illusions arise with chromatically-defined textures with smooth transitions between their colors. This suggests that in respect to color motion perception the complex motions' pathway is only able to accurately process signals from isoluminant colored textures with sharp transitions between colors, and/or moving at high speeds, which is conceivable if it relies on inputs from a hypothetical dual opponent color

  18. Congestive heart failure and central sleep apnea.

    PubMed

    Sands, Scott A; Owens, Robert L

    2015-07-01

    Congestive heart failure (CHF) is among the most common causes of admission to hospitals in the United States, especially in those over age 65. Few data exist regarding the prevalence CHF of Cheyne-Stokes respiration (CSR) owing to congestive heart failure in the intensive care unit (ICU). Nevertheless, CSR is expected to be highly prevalent among those with CHF. Treatment should focus on the underlying mechanisms by which CHF increases loop gain and promotes unstable breathing. Few data are available to determine prevalence of CSR in the ICU, or how CSR might affect clinical management and weaning from mechanical ventilation.

  19. Congestion control in satellite networks

    NASA Astrophysics Data System (ADS)

    Byun, Do Jun

    Due to exponential increases in internet traffic, Active Queue Management (AQM) has been heavily studied by numerous researchers. However, little is known about AQM in satellite networks. A microscopic examination of queueing behavior in satellite networks is conducted to identify problems with applying existing AQM methods. A new AQM method is proposed to overcome the problems and it is validated using a realistic emulation environment and a mathematical model. Three problems that were discovered during the research are discussed in this dissertation. The first problem is oscillatory queueing, which is caused by high buffering due to Performance Enhancing Proxy (PEP) in satellite networks where congestion control after the PEP buffering does not effectively control traffic senders. Existing AQMs that can solve this problem have tail drop queueing that results in consecutive packet drops (global synchronization). A new AQM method called Adaptive Virtual Queue Random Early Detection (AVQRED) is proposed to solve this problem. The second problem is unfair bandwidth sharing caused by inaccurate measurements of per-flow bandwidth usage. AVQRED is enhanced to accurately measure per-flow bandwidth usage to solve this problem without adding much complexity to the algorithm. The third problem is queueing instability caused by buffer flow control where TCP receive windows are adjusted to flow control traffic senders instead of dropping received packets during congestion. Although buffer flow control is quite attractive to satellite networks, queueing becomes unstable because accepting packets instead of dropping them aggravates the congestion level. Furthermore, buffer flow control has abrupt reductions in the TCP receive window size due to high PEP buffering causing more instability. AVQRED with packet drop is proposed to solve this problem. Networks with scarce bandwidth and high propagation delays can not afford to have an unstable AQM. In this research, three problems

  20. Managing congestive heart failure using home telehealth.

    PubMed

    Schneider, Nina M

    2004-10-01

    Congestive heart failure (CHF) is the leading cause of rehospitalization and loss of revenue for home care agencies and hospitals. This article outlines how an agency used telehealth to provide CHF patients quality care and improved outcomes while decreasing the number of skilled home nursing visits and reducing rehospitalization rates to 1.2%.

  1. Never Been KIST: Tor’s Congestion Management Blossoms with Kernel-Informed Socket Transport

    DTIC Science & Technology

    2014-08-01

    CUBIC congestion control algorithm. Shadow Topology Enhancements: To ensure that we are causing the most realistic performance and con- gestion effects...selection [13, 59, 60], client throttling [14, 38, 45], circuit scheduling [57], and flow/congestion control [15]. While some of this work has or will be...congestion local to relays running in the public Tor network, and use them to measure congestion from three live relays under our control . Second, we

  2. Autonomous Congestion Control in Delay-Tolerant Networks

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott C.; Jennings, Esther H.

    2005-01-01

    Congestion control is an important feature that directly affects network performance. Network congestion may cause loss of data or long delays. Although this problem has been studied extensively in the Internet, the solutions for Internet congestion control do not apply readily to challenged network environments such as Delay Tolerant Networks (DTN) where end-to-end connectivity may not exist continuously and latency can be high. In DTN, end-to-end rate control is not feasible. This calls for congestion control mechanisms where the decisions can be made autonomously with local information only. We use an economic pricing model and propose a rule-based congestion control mechanism where each router can autonomously decide on whether to accept a bundle (data) based on local information such as available storage and the value and risk of accepting the bundle (derived from historical statistics).

  3. Fluid-structure coupled computations of the NREL 5MW wind turbine blade during standstill

    NASA Astrophysics Data System (ADS)

    Dose, B.; Rahimi, H.; Herráez, I.; Stoevesandt, B.; Peinke, J.

    2016-09-01

    This work is aimed at investigating the aero-elastic behavior of a wind turbine blade subjected to strong wind speeds during standstill. This type of investigation still remains a challenge for most wind turbine simulation codes. For this purpose, a new developed high fidelity framework for fluid-structure coupled computations of wind turbines is presented and numerical simulations are conducted on the NREL 5MW reference wind turbine. The framework couples the open-source Computational Fluid Dynamics (CFD) toolbox OpenFOAM with an in-house beam solver, based on the Geometrically Exact Beam Theory (GEBT). The obtained results are compared to the aero-elastic tool FAST, which is based on the Blade Element Momentum theory (BEM) and can be considered as a state-of-the-art wind turbine simulation code. The evaluation of the fluid-structure coupled CFD simulations reveals clear differences in the results compared to FAST. While the mean deflections show a reasonable agreement, the dynamics of the edgewise deflections differ significantly. Furthermore, the effect of an explicit coupling versus an implicit coupling strategy on the results is investigated.

  4. An Admission-to-Discharge BNP Increase Is a Predictor of Six-Month All-Cause Death in ADHF Patients: Inferences from Multivariate Analysis Including Admission BNP and Various Clinical Measures of Congestion

    PubMed Central

    De Vecchis, Renato; Ariano, Carmelina; Baldi, Cesare

    2016-01-01

    Background: According to some authors, a single isolated measurement of serum B-type natriuretic peptide (BNP) executed on hospital admission would not be a sufficiently accurate method to predict the outcome of patients with acute decompensated heart failure (ADHF). Aims: To verify this assumption, a retrospective study was conducted on patients hospitalized for ADHF. Our main objective was to ascertain whether there was any difference in midterm mortality among patients with increasing BNP at discharge as compared with those with decreasing BNP at discharge. Methods: Medical records were examined so as to make a partition of the ADHF patient population into two groups, the former characterized by a rise in BNP during hospitalization, and the latter exhibiting a decrease in BNP in the measurement taken at hospital discharge. Results: 177 patients were enrolled in a retrospective study. Among them, 53 patients (30%) had increased BNP at the time of discharge, whereas 124 (70%) showed decreases in serum BNP during their hospital stay. The group with patients who exhibited BNP increases at the time of discharge had a higher degree of congestion evident in the higher frequency of persistent jugular venous distention and persistent orthopnea at discharge. Moreover, patients with increased BNP at the time of discharge had a lower reduction in inferior vena cava maximum diameter (1.58 ± 2.2 mm vs. 6.32 ± 1.82 mm; p (one-way ANOVA) = 0.001). In contrast, there was no significant difference in weight loss when patients with increased BNP at discharge were compared with those with no such increase. A total of 14 patients (7.9%) died during the six-month follow-up period. Multivariable Cox proportional-hazards regression analysis revealed that a BNP increase at the time of discharge was an independent predictor of six-month all-cause mortality after adjustment for persistent jugular venous distention, persistent orthopnea, reduction in inferior vena cava maximum diameter

  5. Pelvic Congestion Syndrome

    PubMed Central

    Durham, Janette D.; Machan, Lindsay

    2013-01-01

    Patients with pelvic congestion syndrome present with otherwise unexplained chronic pelvic pain that has been present for greater than 6 months, and anatomic findings that include pelvic venous insufficiency and pelvic varicosities. It remains an underdiagnosed explanation for pelvic pain in young, premenopausal, usually multiparous females. Symptoms include noncyclical, positional lower back, pelvic and upper thigh pain, dyspareunia, and prolonged postcoital discomfort. Symptoms worsen throughout the day and are exacerbated by activity or prolonged standing. Examination may reveal ovarian tenderness and unusual varicosities—vulvoperineal, posterior thigh, and gluteal. Diagnosis is suspected by clinical history and imaging that demonstrates pelvic varicosities. Venography is usually necessary to confirm ovarian vein reflux, although transvaginal ultrasound may be useful in documenting this finding. Endovascular therapy has been validated by several large patient series with long-term follow-up using standardized pain assessment surveys. Embolization has been shown to be significantly more effective than surgical therapy in improving symptoms in patients who fail hormonal therapy. Although there has been variation in approaches between investigators, the goal is elimination of ovarian vein reflux with or without direct sclerosis of enlarged pelvic varicosities. Symptom reduction is seen in 70 to 90% of the treated females despite technical variation. PMID:24436564

  6. Current Management of Congestive Heart Failure

    PubMed Central

    Lopez, J.F.

    1989-01-01

    Congestive heart failure is still one of the most common causes of death in our society. Treatment should be approached systematically with a set of well-defined objectives, which include rest, a low-sodium diet, inotropic agents, diuretics, and peripheral vasodilators. Patients receiving treatment for congestive heart failure should be examined daily for symptomatic improvement, cardiac signs, and accurate recording of total fluid intake and output. Serum electrolyte levels and chest X-ray films should also be checked intermittently. When using powerful diuretics or vasodilators, the physician should be aware of the risk-benefit ratio because many of these drugs, alone or in combination, may produce undesirable or even fatal side-effects. PMID:20469506

  7. [Current echography diagnosis of pelvic congestion syndrome].

    PubMed

    Malinova, M; Shopov, A

    2012-01-01

    Chronic pelvic pain is a common condition. The sources of pelvic pain are multifactorial, and their causes are difficult to determine. Pelvic congestion syndrome (PCS) is associated with varicose ovarian veins and/or varicose veins in the pelvis. The syndrome is associated with constant dull pelvic pain, abnormal menstrual bleeding, tenderness to touch in lower abdomen, pain during intercourse, painful menstrual periods, vaginal discharge, PCOS. The specific diagnosis of Pelvic Congestion Syndrome is made using several tests which include ultrasound, CAT, MIR, MDCT (multidetector) and venogram. The ultrasound is the first test of choice. It can assess the uterus and other organs in the pelvis. Doppler ultrasound can also help visualize the blood flow and asses the presence of varicosities in the pelvis.

  8. Privacy-Sensitive Congestion Charging

    NASA Astrophysics Data System (ADS)

    Beresford, Alastair R.; Davies, Jonathan J.; Harle, Robert K.

    National-scale congestion charging schemes are increasingly viewed as the most viable long-term strategy for controlling congestion and maintaining the viability of the road network. In this paper we challenge the widely held belief that enforceable and economically viable congestion charging schemes require drivers to give up their location privacy to the government. Instead we explore an alternative scheme where privately-owned cars enforce congestion charge payments by using an on-board vehicle unit containing a camera and wireless communications. Our solution prevents centralised tracking of vehicle movements but raises an important issue: should we trust our neighbours with a little personal information in preference to entrusting it all to the government?

  9. Congested Aggregation via Newtonian Interaction

    NASA Astrophysics Data System (ADS)

    Craig, Katy; Kim, Inwon; Yao, Yao

    2017-08-01

    We consider a congested aggregation model that describes the evolution of a density through the competing effects of nonlocal Newtonian attraction and a hard height constraint. This provides a counterpoint to existing literature on repulsive-attractive nonlocal interaction models, where the repulsive effects instead arise from an interaction kernel or the addition of diffusion. We formulate our model as the Wasserstein gradient flow of an interaction energy, with a penalization to enforce the constraint on the height of the density. From this perspective, the problem can be seen as a singular limit of the Keller-Segel equation with degenerate diffusion. Two key properties distinguish our problem from previous work on height constrained equations: nonconvexity of the interaction kernel (which places the model outside the scope of classical gradient flow theory) and nonlocal dependence of the velocity field on the density (which causes the problem to lack a comparison principle). To overcome these obstacles, we combine recent results on gradient flows of nonconvex energies with viscosity solution theory. We characterize the dynamics of patch solutions in terms of a Hele-Shaw type free boundary problem and, using this characterization, show that in two dimensions patch solutions converge to a characteristic function of a disk in the long-time limit, with an explicit rate on the decay of the energy. We believe that a key contribution of the present work is our blended approach, combining energy methods with viscosity solution theory.

  10. Influence of periodic traffic congestion on epidemic spreading

    NASA Astrophysics Data System (ADS)

    Zheng, Muhua; Ruan, Zhongyuan; Tang, Ming; Do, Younghae; Liu, Zonghua

    2016-11-01

    In the metropolis, traffic congestion has become a very serious problem, especially in rush hours. This congestion causes people to have more chance to contact each other and thus will accelerate epidemic spreading. To explain this observation, we present a reaction-diffusion (RD) model with a periodic varying diffusion rate to represent the daily traveling behaviors of human beings and its influence to epidemic spreading. By extensive numerical simulations, we find that the epidemic spreading can be significantly influenced by traffic congestion where the amplitude, period and duration of diffusion rate are the three key parameters. Furthermore, a brief theory is presented to explain the effects of the three key parameters. These findings suggest that except the normal ways of controlling contagion in working places and long-distance traveling, controlling the contagion in daily traffic congestion may be another effective way to reduce epidemic spreading.

  11. On-board congestion control for satellite packet switching networks

    NASA Technical Reports Server (NTRS)

    Chu, Pong P.

    1991-01-01

    It is desirable to incorporate packet switching capability on-board for future communication satellites. Because of the statistical nature of packet communication, incoming traffic fluctuates and may cause congestion. Thus, it is necessary to incorporate a congestion control mechanism as part of the on-board processing to smooth and regulate the bursty traffic. Although there are extensive studies on congestion control for both baseband and broadband terrestrial networks, these schemes are not feasible for space based switching networks because of the unique characteristics of satellite link. Here, we propose a new congestion control method for on-board satellite packet switching. This scheme takes into consideration the long propagation delay in satellite link and takes advantage of the the satellite's broadcasting capability. It divides the control between the ground terminals and satellite, but distributes the primary responsibility to ground terminals and only requires minimal hardware resource on-board satellite.

  12. Understanding the topological characteristics and flow complexity of urban traffic congestion

    NASA Astrophysics Data System (ADS)

    Wen, Tzai-Hung; Chin, Wei-Chien-Benny; Lai, Pei-Chun

    2017-05-01

    For a growing number of developing cities, the capacities of streets cannot meet the rapidly growing demand of cars, causing traffic congestion. Understanding the spatial-temporal process of traffic flow and detecting traffic congestion are important issues associated with developing sustainable urban policies to resolve congestion. Therefore, the objective of this study is to propose a flow-based ranking algorithm for investigating traffic demands in terms of the attractiveness of street segments and flow complexity of the street network based on turning probability. Our results show that, by analyzing the topological characteristics of streets and volume data for a small fraction of street segments in Taipei City, the most congested segments of the city were identified successfully. The identified congested segments are significantly close to the potential congestion zones, including the officially announced most congested streets, the segments with slow moving speeds at rush hours, and the areas near significant landmarks. The identified congested segments also captured congestion-prone areas concentrated in the business districts and industrial areas of the city. Identifying the topological characteristics and flow complexity of traffic congestion provides network topological insights for sustainable urban planning, and these characteristics can be used to further understand congestion propagation.

  13. Snoring and Nasal Congestion

    MedlinePlus

    ... and soft palate. This negative pressure increases the vibration of these "noise-makers" (the uvula and soft ... is generally considered the noisy breathing caused by vibrations of the upper airway during sleep. In contrast ...

  14. Probability-based TCP congestion control mechanism

    NASA Astrophysics Data System (ADS)

    Xu, Changbiao; Yang, Shizhong; Xian, Yongju

    2005-11-01

    To mitigate TCP global synchronization and improve network throughput, an improved TCP congestion control mechanism is proposed, namely P-TCP, which adopts the probability-based way to adjust congestion window independently when the network occurs congestion. Therefore, some P-TCP connections may decrease the congestion window greatly while other P-TCP connections may decrease the congestion window lightly. Simulation results show that TCP global synchronization can be effectively mitigated, which leads to efficient utilization of network resources as well as the effective mitigation for network congestion. Simulation results also give some valuable references for determining the related parameters in P-TCP.

  15. Analysis of safety factors for urban expressways considering the effect of congestion in Shanghai, China.

    PubMed

    Sun, Jian; Li, Tienan; Li, Feng; Chen, Feng

    2016-10-01

    Urban expressways are the key components of the urban traffic network. The traffic safety situation on expressways directly influences the efficiency of the whole network. A total of 48,325 crashes were recorded by Shanghai Expressway Surveillance System in a three-year period. Considering the different crash mechanisms under different congestion levels, models for the total crashes, non-congested-flow crashes and congested-flow crashes were respectively formulated based on the real-time traffic condition corresponding to each crash. Moreover, considering the potential spatial correlation among segments, the adjacent-correlated spatial and distance-correlated spatial models were formulated and compared to the traditional non-spatial-correlated model. A Bayesian approach was employed to estimate the parameters. The results showed that the congestion index, merging ratio, ramp density, and average daily traffic significantly affect the crash frequency. The safety factors in non-congested flow and congested flow are different; diverging behavior is more risky in non-congested flow, more lanes tend to increase the risk of crashes in congested flow, and horizontal curves tend to decrease the crash risk in congested flow but cause high risk in non-congested flow. In addition, the distance-correlated spatial model is found to be the best-fitting model. The results of this study suggested that dedicated safety countermeasures can be designed for different traffic situations on urban expressways.

  16. Compound heterozygous mutations in the SCN5A-encoded Nav1.5 cardiac sodium channel resulting in atrial standstill and His-Purkinje system disease.

    PubMed

    Baskar, Shankar; Ackerman, Michael J; Clements, Diane; Mayuga, Kenneth A; Aziz, Peter F

    2014-11-01

    An 11-year-old girl on evaluation for syncope was found to have progressive sinus node dysfunction and His-Purkinje system disease with atrial standstill. Genetic analysis revealed compound heterozygous mutations of the SCN5A gene in a novel combination.

  17. Decongestants: OTC Relief for Congestion

    MedlinePlus

    ... individual can purchase each monthRequirement to show photo identification when purchasing the medicineRequirement for retailers to record ... by: familydoctor.org editorial staff Categories: Drugs, Procedures & Devices, Over-the-counter Products, Your Health ResourcesTags: congestion, ...

  18. Heart failure after transvenous closure of atrial septal defect associated with atrial standstill and thiamine-responsive megaloblastic anemia.

    PubMed

    Doğan, Vehbi; Senocak, Filiz; Orün, Utku Arman; Ceylan, Ozben

    2013-10-01

    Despite advances in device closure for atrial septal defect, post-closure heart failure remains a clinical problem in adult patients but is seen only rarely in children. An eight-year-old boy, who had been followed by a local pediatrician with the diagnosis of diabetes mellitus and congenital heart disease, was consulted to us for cardiac re-evaluation. Electrocardiography demonstrated absent P waves, and echocardiography revealed enlargement of the right ventricle and both atria and secundum atrial septal defect. With the diagnosis of atrial standstill, secundum atrial septal defect and thiamine-responsive megaloblastic anemia, acute heart failure developed after transvenous closure of the atrial septal defect, which improved dramatically with thiamine and supportive treatment.

  19. Signalling and obfuscation for congestion control

    NASA Astrophysics Data System (ADS)

    Mareček, Jakub; Shorten, Robert; Yu, Jia Yuan

    2015-10-01

    We aim to reduce the social cost of congestion in many smart city applications. In our model of congestion, agents interact over limited resources after receiving signals from a central agent that observes the state of congestion in real time. Under natural models of agent populations, we develop new signalling schemes and show that by introducing a non-trivial amount of uncertainty in the signals, we reduce the social cost of congestion, i.e., improve social welfare. The signalling schemes are efficient in terms of both communication and computation, and are consistent with past observations of the congestion. Moreover, the resulting population dynamics converge under reasonable assumptions.

  20. Teaching Congestive Heart Failure to Doctor of Pharmacy Students.

    ERIC Educational Resources Information Center

    Parker, Robert B.

    1992-01-01

    This paper summarizes a lecture given to pharmacy students that emphasizes the pathophysiologic mechanisms causing congestive heart failure and the effects of drugs on these mechanisms. The approach shows the importance of drug therapy in this disorder and how this knowledge can improve patient care. An appendix provides a case study. (GLR)

  1. Congestion phenomena on complex networks.

    PubMed

    De Martino, Daniele; Dall'asta, Luca; Bianconi, Ginestra; Marsili, Matteo

    2009-01-01

    We define a minimal model of traffic flows in complex networks in order to study the trade-off between topological-based and traffic-based routing strategies. The resulting collective behavior is obtained analytically for an ensemble of uncorrelated networks and summarized in a rich phase diagram presenting second-order as well as first-order phase transitions between a free-flow phase and a congested phase. We find that traffic control improves global performance, enlarging the free-flow region in parameter space only in heterogeneous networks. Traffic control introduces nonlinear effects and, beyond a critical strength, may trigger the appearance of a congested phase in a discontinuous manner. The model also reproduces the crossover in the scaling of traffic fluctuations empirically observed on the Internet.

  2. Pelvic congestion syndrome and pelvic varicosities.

    PubMed

    Koo, Sonya; Fan, Chieh-Min

    2014-06-01

    Pelvic venous insufficiency (PVI), defined as retrograde flow in the gonadal and internal iliac veins, is the underlying cause of pelvic congestion syndrome (PCS), a common cause of disabling chronic pelvic pain in women of child-bearing age. PCS is a chronic pain syndrome characterized by positional pelvic pain that is worse in the upright position and is associated with pelvic and vulvar varicosities as well as symptoms of dyspareunia and postcoital pain. Through collaterals to the lower extremity venous system, PVI may also contribute to varicose vein formation and recurrence in the lower extremities. Endovascular embolization of the ovarian and internal iliac veins has become the treatment of choice for PVI and PCS. This article reviews the pelvic retroperitoneal venous anatomy, pathophysiology of PCS, treatment options and techniques, and clinical outcomes of embolotherapy for PCS.

  3. Avoiding congestion in recommender systems

    NASA Astrophysics Data System (ADS)

    Ren, Xiaolong; Lü, Linyuan; Liu, Runran; Zhang, Jianlin

    2014-06-01

    Recommender systems use the historical activities and personal profiles of users to uncover their preferences and recommend objects. Most of the previous methods are based on objects’ (and/or users’) similarity rather than on their difference. Such approaches are subject to a high risk of increasingly exposing users to a narrowing band of popular objects. As a result, a few objects may be recommended to an enormous number of users, resulting in the problem of recommendation congestion, which is to be avoided, especially when the recommended objects are limited resources. In order to quantitatively measure a recommendation algorithm's ability to avoid congestion, we proposed a new metric inspired by the Gini index, which is used to measure the inequality of the individual wealth distribution in an economy. Besides this, a new recommendation method called directed weighted conduction (DWC) was developed by considering the heat conduction process on a user-object bipartite network with different thermal conductivities. Experimental results obtained for three benchmark data sets showed that the DWC algorithm can effectively avoid system congestion, and greatly improve the novelty and diversity, while retaining relatively high accuracy, in comparison with the state-of-the-art methods.

  4. Green supply chain: Simulating road traffic congestion

    NASA Astrophysics Data System (ADS)

    Jalal, Muhammad Zulqarnain Hakim Abd; Nawawi, Mohd Kamal Mohd; Laailatul Hanim Mat Desa, Wan; Khalid, Ruzelan; Khalid Abduljabbar, Waleed; Ramli, Razamin

    2017-09-01

    With the increasing awareness of the consumers about environmental issues, businesses, households and governments increasingly want use green products and services which lead to green supply chain. This paper discusses a simulation study of a selected road traffic system that will contribute to the air pollution if in the congestion state. Road traffic congestion (RTC) can be caused by a temporary obstruction, a permanent capacity bottleneck in the network itself, and stochastic fluctuation in demand within a particular sector of the network, leading to spillback and queue propagation. A discrete-event simulation model is developed to represent the real traffic light control (TLC) system condition during peak hours. Certain performance measures such as average waiting time and queue length were measured using the simulation model. Existing system uses pre-set cycle time to control the light changes which is fixed time cycle. In this research, we test several other combination of pre-set cycle time with the objective to find the best system. In addition, we plan to use a combination of the pre-set cycle time and a proximity sensor which have the authority to manipulate the cycle time of the lights. The sensors work in such situation when the street seems to have less occupied vehicles, obviously it may not need a normal cycle for green light, and automatically change the cycle to street where vehicle is present.

  5. Analysis of random drop for gateway congestion control. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Hashem, Emam Salaheddin

    1989-01-01

    Lately, the growing demand on the Internet has prompted the need for more effective congestion control policies. Currently No Gateway Policy is used to relieve and signal congestion, which leads to unfair service to the individual users and a degradation of overall network performance. Network simulation was used to illustrate the character of Internet congestion and its causes. A newly proposed gateway congestion control policy, called Random Drop, was considered as a promising solution to the pressing problem. Random Drop relieves resource congestion upon buffer overflow by choosing a random packet from the service queue to be dropped. The random choice should result in a drop distribution proportional to the bandwidth distribution among all contending TCP connections, thus applying the necessary fairness. Nonetheless, the simulation experiments demonstrate several shortcomings with this policy. Because Random Drop is a congestion control policy, which is not applied until congestion has already occurred, it usually results in a high drop rate that hurts too many connections including well-behaved ones. Even though the number of packets dropped is different from one connection to another depending on the buffer utilization upon overflow, the TCP recovery overhead is high enough to neutralize these differences, causing unfair congestion penalties. Besides, the drop distribution itself is an inaccurate representation of the average bandwidth distribution, missing much important information about the bandwidth utilization between buffer overflow events. A modification of Random Drop to do congestion avoidance by applying the policy early was also proposed. Early Random Drop has the advantage of avoiding the high drop rate of buffer overflow. The early application of the policy removes the pressure of congestion relief and allows more accurate signaling of congestion. To be used effectively, algorithms for the dynamic adjustment of the parameters of Early Random Drop

  6. Liver congestion in heart failure contributes to inappropriately increased serum hepcidin despite anemia.

    PubMed

    Ohno, Yukako; Hanawa, Haruo; Jiao, Shuang; Hayashi, Yuka; Yoshida, Kaori; Suzuki, Tomoyasu; Kashimura, Takeshi; Obata, Hiroaki; Tanaka, Komei; Watanabe, Tohru; Minamino, Tohru

    2015-01-01

    Hepcidin is a key regulator of mammalian iron metabolism and mainly produced by the liver. Hepcidin excess causes iron deficiency and anemia by inhibiting iron absorption from the intestine and iron release from macrophage stores. Anemia is frequently complicated with heart failure. In heart failure patients, the most frequent histologic appearance of liver is congestion. However, it remains unclear whether liver congestion associated with heart failure influences hepcidin production, thereby contributing to anemia and functional iron deficiency. In this study, we investigated this relationship in clinical and basic studies. In clinical studies of consecutive heart failure patients (n = 320), anemia was a common comorbidity (41%). In heart failure patients without active infection and ongoing cancer (n = 30), log-serum hepcidin concentration of patients with liver congestion was higher than those without liver congestion (p = 0.0316). Moreover, in heart failure patients with liver congestion (n = 19), the anemia was associated with the higher serum hepcidin concentrations, which is a type of anemia characterized by induction of hepcidin. Subsequently, we produced a rat model of heart failure with liver congestion by injecting monocrotaline that causes pulmonary hypertension. The monocrotaline-treated rats displayed liver congestion with increase of hepcidin expression at 4 weeks after monocrotaline injection, followed by anemia and functional iron deficiency observed at 5 weeks. We conclude that liver congestion induces hepcidin production, which may result in anemia and functional iron deficiency in some patients with heart failure.

  7. Toward an Engineering Model for the Aerodynamic Forces Acting on Wind Turbine Blades in Quasisteady Standstill and Blade Installation Situations

    NASA Astrophysics Data System (ADS)

    Gaunaa, Mac; Heinz, Joachim; Skrzypiński, Witold

    2016-09-01

    The crossflow principle is one of the key elements used in engineering models for prediction of the aerodynamic loads on wind turbine blades in standstill or blade installation situations, where the flow direction relative to the wind turbine blade has a component in the direction of the blade span direction. In the present work, the performance of the crossflow principle is assessed on the DTU 10MW reference blade using extensive 3D CFD calculations. Analysis of the computational results shows that there is only a relatively narrow region in which the crossflow principle describes the aerodynamic loading well. In some conditions the deviation of the predicted loadings can be quite significant, having a large influence on for instance the integral aerodynamic moments around the blade centre of mass; which is very important for single blade installation applications. The main features of these deviations, however, have a systematic behaviour on all force components, which in this paper is employed to formulate the first version of an engineering correction method to the crossflow principle applicable for wind turbine blades. The new correction model improves the agreement with CFD results for the key aerodynamic loads in crossflow situations. The general validity of this model for other blade shapes should be investigated in subsequent works.

  8. Evaluation of performance characteristics of the medicinal leech (Hirudo medicinalis) for the treatment of venous congestion.

    PubMed

    Conforti, Michael L; Connor, Nadine P; Heisey, Dennis M; Hartig, Gregory K

    2002-01-01

    Medicinal leeches (Hirudo medicinalis) are a standard treatment for venous congestion, a complication that can occur after reconstructive surgery. If the cause of venous congestion cannot be surgically corrected, then medicinal leeches are used to temporarily increase perfusion levels and maintain physiologic requirements within the congested tissue. Leeches increase perfusion within congested tissue by actively drawing off blood as a bloodmeal. Furthermore, the leech bite continues to bleed and relieve congestion after detachment because of the anticoagulation effects of leech saliva left behind in the bite. In a porcine model, a 10 x 10 cm cutaneous flank flap was congested by clamping the venae comitantes. Four medicinal leeches were allowed to attach to the congested flap, and parameters of active feeding and passive bleeding after detachment were recorded. The average bloodmeal volume for the medicinal leeches was 2.45 ml. Average passive bleeding for the first 2 and 4 hours after leech detachment totaled 2.21 and 2.50 ml, respectively, with 90 percent of passive bleeding occurring within 5 hours after detachment. Laser Doppler imaging indicated that the spatial arrangement of surface perfusion increases were localized to a 1.6-cm-diameter circle around the leech head (bite) and corresponded well with the visual return of normal skin tones to the same area. This study provides a realistic and quantitative estimate of the spatial and volumetric characteristics of leech feeding and passive bleeding using a clinically relevant model of acute, severe congestion.

  9. Multipath Binomial Congestion Control Algorithms

    NASA Astrophysics Data System (ADS)

    Le, Tuan Anh; Hong, Choong Seon; Lee, Sungwon

    Nowadays portable devices with multiple wireless interfaces and using multimedia services are becoming more popular on the Internet. This paper describes a family of multipath binomial congestion control algorithms for audio/video streaming, where a low variant of transmission rate is important. We extend the fluid model of binomial algorithms for single-path transmission to support the concurrent transmission of packets across multiple paths. We focus on the extension of two particular algorithms, SQRT and IIAD, for multiple paths, called MPSQRT and MPIIAD, respectively. Additionally, we apply the design technique (using the multipath fluid model) for multipath TCP (MPTCP) into the extension of SQRT and IIAD, called fbMPSQRT and fbMPIIAD, respectively. Both two approaches ensure that multipath binomial congestion control algorithms achieve load-balancing, throughput improvement, and fairness to single-path binomial algorithms at shared bottlenecks. Through the simulations and comparison with the uncoordinated protocols MPSQRT/MPIIAD, fbMPSQRT/fbMPIIAD and MPTCP, we find that our extended multipath transport protocols can preserve lower latency and transmission rate variance than MPTCP, fairly share with single-path SQRT/IIAD, MPTCP and TCP, and also can achieve throughput improvements and load-balancing equivalent to those of MPTCP under various scenarios and network conditions.

  10. Understanding congestion in China's medical market: an incentive structure perspective.

    PubMed

    Sun, Zesheng; Wang, Shuhong; Barnes, Stephen R

    2016-04-01

    Congestion has become one of the most important factors leading to patient dissatisfaction and doctor-patient conflicts in the medical market of China. In this study, we explore the causes and effects of structural congestion in the Chinese medical market from an incentive structure perspective. Our analysis reveals that prior medical system reforms with price regulation in China have induced hospitals to establish incentives for capital-intensive investments, while ignoring human capital, and have driven medical staff and patients to higher-level hospitals, reinforcing an incentive structure in which congestion in higher-level hospitals and idle resources in lower-level hospitals coexist. The existing incentive structure has led to cost increases and degradation of human capital and specific factor effects. Recent reforms to reduce congestion in the Chinese medical market were not effective. Most of them had no impact on and did not involve the existing distorted incentive structure. Future reforms should consider rebalancing expectations for medical quality, free flow of human capital and price regulation reforms to rebuild a new incentive structure. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  11. [Anemia in congestive heart failure].

    PubMed

    Abassade, P; Rabenirina, F; Garcon, P; Antakly, Y; Cador, R

    2009-11-01

    Anemia is a common disorder in congestive heart failure and an independant prognostic factor. The aims of this study are to evaluate the prevalence of anemia among a population of in-hospital congestive heart failure patients, to compare anemic patients (A) with non anemic patients (NA) and to study their cares. One hundred and thirty-two patients, 70 men (53%), et 62 women (47%) are enrolled. Mean age is 76.4+/-13.5 years. The prevalence of anemia (WHO criteria) is 49%. Patients A are older than NA: 79.1+/-13.8 years versus 73.8+/-12.9 years (p=0.025), renal function is more altered in A than in NA, creatinine clearance is 56.5 ml/min (A) versus 76.2 ml/min (NA) (p=0.003). Ejection fraction (EF) is lower in A than in NA: 35.1+/-15.3% versus 50.9+/-15.9%, (p<0.0001.) Anemia is less frequent in preserved EF (28%) than in low EF (63%) (p<0.0001). Hospitalization duration is longer in A than in NA: 10.7+/-10.1 days versus 6.9+/-3.7 days (p=0.005). There are more re hospitalized patients among A than NA: 38 versus 10 (p=0.0001). There is a significant difference of survival of NA versus A at day 614 (p=0.03). Anemia is frequent in our population, and is associated with others prognostic factors and comorbidity.

  12. Relationship Between Carbon Dioxide Levels and Reported Congestion and Headaches on the International Space Station

    NASA Technical Reports Server (NTRS)

    Cole, Robert; Wear, Mary; Young, Millennia; Cobel, Christopher; Mason, Sara

    2017-01-01

    Congestion is commonly reported during spaceflight, and most crewmembers have reported using medications for congestion during International Space Station (ISS) missions. Although congestion has been attributed to fluid shifts during spaceflight, fluid status reaches equilibrium during the first week after launch while congestion continues to be reported throughout long duration missions. Congestion complaints have anecdotally been reported in relation to ISS CO2 levels; this evaluation was undertaken to determine whether or not an association exists. METHODS: Reported headaches, congestion symptoms, and CO2 levels were obtained for ISS expeditions 2-31, and time-weighted means and single-point maxima were determined for 24-hour (24hr) and 7-day (7d) periods prior to each weekly private medical conference. Multiple imputation addressed missing data, and logistic regression modeled the relationship between probability of reported event of congestion or headache and CO2 levels, adjusted for possible confounding covariates. The first seven days of spaceflight were not included to control for fluid shifts. Data were evaluated to determine the concentration of CO2 required to maintain the risk of congestion below 1% to allow for direct comparison with a previously published evaluation of CO2 concentrations and headache. RESULTS: This study confirmed a previously identified significant association between CO2 and headache and also found a significant association between CO2 and congestion. For each 1-mm Hg increase in CO2, the odds of a crew member reporting congestion doubled. The average 7-day CO2 would need to be maintained below 1.5 mmHg to keep the risk of congestion below 1%. The predicted probability curves of ISS headache and congestion curves appear parallel when plotted against ppCO2 levels with congestion occurring at approximately 1mmHg lower than a headache would be reported. DISCUSSION: While the cause of congestion is multifactorial, this study showed

  13. Binomial congestion control at receivers for multicast

    NASA Astrophysics Data System (ADS)

    Zhang, Bing; Liu, Zengji; Xu, Yayan; Li, Zhen; Zhang, Shi

    2004-09-01

    A single rate multicast congestion control for streaming media applications called Binomial congestion control At Receivers for Multicast (BARM) is proposed. Combining aspects of window-based and rate-based congestion control, the protocol shifts most of the congestion control mechanisms to multicast receivers. The main features of BARM are as follows. (1) The protocol adopts binomial algorithm (k=l=0.5, α=0.28, β=0.2 for our implementation) to adjust congestion window, which not only provides TCP-friendliness but decreases abrupt rate fluctuations, making it suitable for real time streaming media multicast applications. (2) The binomial algorithm is executed at the receivers instead of at the sender; to do this, a congestion window is maintained and updated separately by each receiver. Hence the protocol not only has a better scalability but reduces the burden of the sender significantly and is suitable to Client/Server model. (3) The congestion window is converted to the expected receiving rate which is then fed back to the sender if permitted. Compared to window feedback scheme, rate feedback scheme is simpler and increases the scalability. (4) The representative approach is used to suppress the feedback implosion. Simulations results indicate that BARM shows good fairness, TCP-friendliness, smoothness, scalability, and acceptable responsiveness.

  14. Stochastic Congestion Control in Wireless Sensor Networks

    NASA Astrophysics Data System (ADS)

    Kim, Hyung Seok; Lee, Seok; Kim, Namhoon

    In this paper, an effective congestion control algorithm is proposed to increase the end-to-end delivery success ratio of upstream traffic by reduction of buffer drop probabilities and their deviation in wireless sensor networks. According to the queue length of parent and child nodes, each child node chooses one of the parents as the next hop to the sink and controls the delay before transmission begins. It balances traffics among parents and mitigates congestion based on congestion level of a node. Simulation results show that the proposed algorithm reduces buffer drop probabilities and their deviation and increases the end-to-end delivery success ratio in wireless sensor networks.

  15. Understanding congested travel in urban areas

    NASA Astrophysics Data System (ADS)

    Çolak, Serdar; Lima, Antonio; González, Marta C.

    2016-03-01

    Rapid urbanization and increasing demand for transportation burdens urban road infrastructures. The interplay of number of vehicles and available road capacity on their routes determines the level of congestion. Although approaches to modify demand and capacity exist, the possible limits of congestion alleviation by only modifying route choices have not been systematically studied. Here we couple the road networks of five diverse cities with the travel demand profiles in the morning peak hour obtained from billions of mobile phone traces to comprehensively analyse urban traffic. We present that a dimensionless ratio of the road supply to the travel demand explains the percentage of time lost in congestion. Finally, we examine congestion relief under a centralized routing scheme with varying levels of awareness of social good and quantify the benefits to show that moderate levels are enough to achieve significant collective travel time savings.

  16. Understanding congested travel in urban areas.

    PubMed

    Çolak, Serdar; Lima, Antonio; González, Marta C

    2016-03-15

    Rapid urbanization and increasing demand for transportation burdens urban road infrastructures. The interplay of number of vehicles and available road capacity on their routes determines the level of congestion. Although approaches to modify demand and capacity exist, the possible limits of congestion alleviation by only modifying route choices have not been systematically studied. Here we couple the road networks of five diverse cities with the travel demand profiles in the morning peak hour obtained from billions of mobile phone traces to comprehensively analyse urban traffic. We present that a dimensionless ratio of the road supply to the travel demand explains the percentage of time lost in congestion. Finally, we examine congestion relief under a centralized routing scheme with varying levels of awareness of social good and quantify the benefits to show that moderate levels are enough to achieve significant collective travel time savings.

  17. Congestion and cascades in payment systems

    NASA Astrophysics Data System (ADS)

    Beyeler, Walter E.; Glass, Robert J.; Bech, Morten L.; Soramäki, Kimmo

    2007-10-01

    We develop a parsimonious model of the interbank payment system. The model incorporates an endogenous instruction arrival process, a scale-free topology of payments between banks, a fixed total liquidity which limits banks’ capacity to process arriving instructions, and a global market that distributes liquidity. We find that at low liquidity the system becomes congested and payment settlement loses correlation with payment instruction arrival, becoming coupled across the network. The onset of congestion is evidently related to the relative values of three characteristic times: the time for banks’ net position to return to 0, the time for a bank to exhaust its liquidity endowment, and the liquidity market relaxation time. In the congested regime settlement takes place in cascades having a characteristic length scale. A global liquidity market substantially attenuates congestion, requiring only a small fraction of the payment-induced liquidity flow to achieve strong beneficial effects.

  18. Traffic congestion in interconnected complex networks

    NASA Astrophysics Data System (ADS)

    Tan, Fei; Wu, Jiajing; Xia, Yongxiang; Tse, Chi K.

    2014-06-01

    Traffic congestion in isolated complex networks has been investigated extensively over the last decade. Coupled network models have recently been developed to facilitate further understanding of real complex systems. Analysis of traffic congestion in coupled complex networks, however, is still relatively unexplored. In this paper, we try to explore the effect of interconnections on traffic congestion in interconnected Barabási-Albert scale-free networks. We find that assortative coupling can alleviate traffic congestion more readily than disassortative and random coupling when the node processing capacity is allocated based on node usage probability. Furthermore, the optimal coupling probability can be found for assortative coupling. However, three types of coupling preferences achieve similar traffic performance if all nodes share the same processing capacity. We analyze interconnected Internet autonomous-system-level graphs of South Korea and Japan and obtain similar results. Some practical suggestions are presented to optimize such real-world interconnected networks accordingly.

  19. Understanding congested travel in urban areas

    PubMed Central

    Çolak, Serdar; Lima, Antonio; González, Marta C.

    2016-01-01

    Rapid urbanization and increasing demand for transportation burdens urban road infrastructures. The interplay of number of vehicles and available road capacity on their routes determines the level of congestion. Although approaches to modify demand and capacity exist, the possible limits of congestion alleviation by only modifying route choices have not been systematically studied. Here we couple the road networks of five diverse cities with the travel demand profiles in the morning peak hour obtained from billions of mobile phone traces to comprehensively analyse urban traffic. We present that a dimensionless ratio of the road supply to the travel demand explains the percentage of time lost in congestion. Finally, we examine congestion relief under a centralized routing scheme with varying levels of awareness of social good and quantify the benefits to show that moderate levels are enough to achieve significant collective travel time savings. PMID:26978719

  20. Traffic congestion in interconnected complex networks.

    PubMed

    Tan, Fei; Wu, Jiajing; Xia, Yongxiang; Tse, Chi K

    2014-06-01

    Traffic congestion in isolated complex networks has been investigated extensively over the last decade. Coupled network models have recently been developed to facilitate further understanding of real complex systems. Analysis of traffic congestion in coupled complex networks, however, is still relatively unexplored. In this paper, we try to explore the effect of interconnections on traffic congestion in interconnected Barabási-Albert scale-free networks. We find that assortative coupling can alleviate traffic congestion more readily than disassortative and random coupling when the node processing capacity is allocated based on node usage probability. Furthermore, the optimal coupling probability can be found for assortative coupling. However, three types of coupling preferences achieve similar traffic performance if all nodes share the same processing capacity. We analyze interconnected Internet autonomous-system-level graphs of South Korea and Japan and obtain similar results. Some practical suggestions are presented to optimize such real-world interconnected networks accordingly.

  1. Route Optimization for Offloading Congested Meter Fixes

    NASA Technical Reports Server (NTRS)

    Xue, Min; Zelinski, Shannon

    2016-01-01

    The Optimized Route Capability (ORC) concept proposed by the FAA facilitates traffic managers to identify and resolve arrival flight delays caused by bottlenecks formed at arrival meter fixes when there exists imbalance between arrival fixes and runways. ORC makes use of the prediction capability of existing automation tools, monitors the traffic delays based on these predictions, and searches the best reroutes upstream of the meter fixes based on the predictions and estimated arrival schedules when delays are over a predefined threshold. Initial implementation and evaluation of the ORC concept considered only reroutes available at the time arrival congestion was first predicted. This work extends previous work by introducing an additional dimension in reroute options such that ORC can find the best time to reroute and overcome the 'firstcome- first-reroute' phenomenon. To deal with the enlarged reroute solution space, a genetic algorithm was developed to solve this problem. Experiments were conducted using the same traffic scenario used in previous work, when an arrival rush was created for one of the four arrival meter fixes at George Bush Intercontinental Houston Airport. Results showed the new approach further improved delay savings. The suggested route changes from the new approach were on average 30 minutes later than those using other approaches, and fewer numbers of reroutes were required. Fewer numbers of reroutes reduce operational complexity and later reroutes help decision makers deal with uncertain situations.

  2. Bortezomib-induced Severe Congestive Heart Failure

    PubMed Central

    Jerkins, James H.; Suciu, Anca; Mazimba, Sula; Calvo, Alejandro

    2010-01-01

    The clinical manifestations of anti-cancer drug associated cardiac side effects are diverse and can range from acutely induced cardiac arrhythmias to severe contractile dysfunction, and potentially fatal heart failure. Anthracyclines and trastuzumab cardiac toxicity have been well described and left ventricular ejection fraction (LVEF) evaluation is commonly performed before their use. Bortezomib (Velcade), a potent, specific and reversible proteasome inhibitor is approved for treatment of multiple myeloma (MM). The incidence of cardiac failure associated with bortezomib therapy in clinical trials remains incidental. Acute exacerbation of pre-existing congestive cardiac failure has been associated with this therapy but de novo cardiomyopathy has been reported in only one patient receiving bortezomib for small cell lung cancer. As a result, cardiac evaluation is not normally ordered before its use. We describe a 50-year-old female with newly diagnosed MM and no risk factors for cardiac disease that unexpectedly developed florid heart failure after 2 cycles of bortezomib and low-dose dexamethasone. 2-D echocardiogram showed dilated cardiomyopathy with severely decreased LVEF; no changes consistent with amyloid deposits or myocardial scarring were described. Coronary angiogram ruled out coronary artery disease. The mechanism of bortezomib-induced cardiomyopathy has been postulated to be through fluid retention. Based on literature review we hypothesize that the disruption of the ubiquitin-proteasome system by bortezomib may cause cardiomyopathy and severe cardiac failure. As Bortezomib is a new and promising therapy for MM patients, we recommend routinely monitoring cardiac parameters in patients undergoing this treatment.

  3. Rerouting algorithms solving the air traffic congestion

    NASA Astrophysics Data System (ADS)

    Adacher, Ludovica; Flamini, Marta; Romano, Elpidio

    2017-06-01

    Congestion in the air traffic network is a problem with an increasing relevance for airlines costs as well as airspace safety. One of the major issue is the limited operative capacity of the air network. In this work an Autonomous Agent approach is proposed to solve in real time the problem of air traffic congestion. The air traffic infrastructures are modeled with a graph and are considered partitioned in different sectors. Each sector has its own decision agent dealing with the air traffic control involved in it. Each agent sector imposes a real time aircraft scheduling to respect both delay and capacity constrains. When a congestion is predicted, a new aircraft scheduling is computed. Congestion is solved when the capacity constrains are satisfied once again. This can be done by delaying on ground aircraft or/and rerouting aircraft and/or postponing the congestion. We have tested two different algorithms that calculate K feasible paths for each aircraft involved in the congestion. Some results are reported on North Italian air space.

  4. Large-Scale Transportation Network Congestion Evolution Prediction Using Deep Learning Theory

    PubMed Central

    Ma, Xiaolei; Yu, Haiyang; Wang, Yunpeng; Wang, Yinhai

    2015-01-01

    Understanding how congestion at one location can cause ripples throughout large-scale transportation network is vital for transportation researchers and practitioners to pinpoint traffic bottlenecks for congestion mitigation. Traditional studies rely on either mathematical equations or simulation techniques to model traffic congestion dynamics. However, most of the approaches have limitations, largely due to unrealistic assumptions and cumbersome parameter calibration process. With the development of Intelligent Transportation Systems (ITS) and Internet of Things (IoT), transportation data become more and more ubiquitous. This triggers a series of data-driven research to investigate transportation phenomena. Among them, deep learning theory is considered one of the most promising techniques to tackle tremendous high-dimensional data. This study attempts to extend deep learning theory into large-scale transportation network analysis. A deep Restricted Boltzmann Machine and Recurrent Neural Network architecture is utilized to model and predict traffic congestion evolution based on Global Positioning System (GPS) data from taxi. A numerical study in Ningbo, China is conducted to validate the effectiveness and efficiency of the proposed method. Results show that the prediction accuracy can achieve as high as 88% within less than 6 minutes when the model is implemented in a Graphic Processing Unit (GPU)-based parallel computing environment. The predicted congestion evolution patterns can be visualized temporally and spatially through a map-based platform to identify the vulnerable links for proactive congestion mitigation. PMID:25780910

  5. The congestion control algorithm based on queue management of each node in mobile ad hoc networks

    NASA Astrophysics Data System (ADS)

    Wei, Yifei; Chang, Lin; Wang, Yali; Wang, Gaoping

    2016-12-01

    This paper proposes an active queue management mechanism, considering the node's own ability and its importance in the network to set the queue threshold. As the network load increases, local congestion of mobile ad hoc network may lead to network performance degradation, hot node's energy consumption increase even failure. If small energy nodes congested because of forwarding data packets, then when it is used as the source node will cause a lot of packet loss. This paper proposes an active queue management mechanism, considering the node's own ability and its importance in the network to set the queue threshold. Controlling nodes buffer queue in different levels of congestion area probability by adjusting the upper limits and lower limits, thus nodes can adjust responsibility of forwarding data packets according to their own situation. The proposed algorithm will slow down the send rate hop by hop along the data package transmission direction from congestion node to source node so that to prevent further congestion from the source node. The simulation results show that, the algorithm can better play the data forwarding ability of strong nodes, protect the weak nodes, can effectively alleviate the network congestion situation.

  6. Large-scale transportation network congestion evolution prediction using deep learning theory.

    PubMed

    Ma, Xiaolei; Yu, Haiyang; Wang, Yunpeng; Wang, Yinhai

    2015-01-01

    Understanding how congestion at one location can cause ripples throughout large-scale transportation network is vital for transportation researchers and practitioners to pinpoint traffic bottlenecks for congestion mitigation. Traditional studies rely on either mathematical equations or simulation techniques to model traffic congestion dynamics. However, most of the approaches have limitations, largely due to unrealistic assumptions and cumbersome parameter calibration process. With the development of Intelligent Transportation Systems (ITS) and Internet of Things (IoT), transportation data become more and more ubiquitous. This triggers a series of data-driven research to investigate transportation phenomena. Among them, deep learning theory is considered one of the most promising techniques to tackle tremendous high-dimensional data. This study attempts to extend deep learning theory into large-scale transportation network analysis. A deep Restricted Boltzmann Machine and Recurrent Neural Network architecture is utilized to model and predict traffic congestion evolution based on Global Positioning System (GPS) data from taxi. A numerical study in Ningbo, China is conducted to validate the effectiveness and efficiency of the proposed method. Results show that the prediction accuracy can achieve as high as 88% within less than 6 minutes when the model is implemented in a Graphic Processing Unit (GPU)-based parallel computing environment. The predicted congestion evolution patterns can be visualized temporally and spatially through a map-based platform to identify the vulnerable links for proactive congestion mitigation.

  7. Frame Transmission Efficiency-Based Cross-Layer Congestion Notification Scheme in Wireless Ad Hoc Networks

    PubMed Central

    He, Huaguang; Li, Taoshen; Feng, Luting; Ye, Jin

    2017-01-01

    Different from the traditional wired network, the fundamental cause of transmission congestion in wireless ad hoc networks is medium contention. How to utilize the congestion state from the MAC (Media Access Control) layer to adjust the transmission rate is core work for transport protocol design. However, recent works have shown that the existing cross-layer congestion detection solutions are too complex to be deployed or not able to characterize the congestion accurately. We first propose a new congestion metric called frame transmission efficiency (i.e., the ratio of successful transmission delay to the frame service delay), which describes the medium contention in a fast and accurate manner. We further present the design and implementation of RECN (ECN and the ratio of successful transmission delay to the frame service delay in the MAC layer, namely, the frame transmission efficiency), a general supporting scheme that adjusts the transport sending rate through a standard ECN (Explicit Congestion Notification) signaling method. Our method can be deployed on commodity switches with small firmware updates, while making no modification on end hosts. We integrate RECN transparently (i.e., without modification) with TCP on NS2 simulation. The experimental results show that RECN remarkably improves network goodput across multiple concurrent TCP flows. PMID:28714898

  8. Frame Transmission Efficiency-Based Cross-Layer Congestion Notification Scheme in Wireless Ad Hoc Networks.

    PubMed

    He, Huaguang; Li, Taoshen; Feng, Luting; Ye, Jin

    2017-07-15

    Different from the traditional wired network, the fundamental cause of transmission congestion in wireless ad hoc networks is medium contention. How to utilize the congestion state from the MAC (Media Access Control) layer to adjust the transmission rate is core work for transport protocol design. However, recent works have shown that the existing cross-layer congestion detection solutions are too complex to be deployed or not able to characterize the congestion accurately. We first propose a new congestion metric called frame transmission efficiency (i.e., the ratio of successful transmission delay to the frame service delay), which describes the medium contention in a fast and accurate manner. We further present the design and implementation of RECN (ECN and the ratio of successful transmission delay to the frame service delay in the MAC layer, namely, the frame transmission efficiency), a general supporting scheme that adjusts the transport sending rate through a standard ECN (Explicit Congestion Notification) signaling method. Our method can be deployed on commodity switches with small firmware updates, while making no modification on end hosts. We integrate RECN transparently (i.e., without modification) with TCP on NS2 simulation. The experimental results show that RECN remarkably improves network goodput across multiple concurrent TCP flows.

  9. Avoiding congestion through dynamic load control

    NASA Astrophysics Data System (ADS)

    Hnatyshin, Vasil; Sethi, Adarshpal S.

    2001-07-01

    The current best effort approach to quality of service in the Internet can no longer satisfy a diverse variety of customer service requirements, and that is why there is a need for alternative strategies. In order to solve this problem a number of service differentiation models have been proposed. Unfortunately, these schemes often fail to provide proper service differentiation during periods of congestion. To deal with the issue of congestion, we introduce a new load control mechanism that eliminates congestion based on the feedback from the network core by dynamically adjusting traffic load at the network boundary. We introduce four methods for calculating load distribution among the ingress routers and among different flows in each ingress router, and we evaluate these proposed methods through simulation.

  10. Fixed-rate layered multicast congestion control

    NASA Astrophysics Data System (ADS)

    Bing, Zhang; Bing, Yuan; Zengji, Liu

    2006-10-01

    A new fixed-rate layered multicast congestion control algorithm called FLMCC is proposed. The sender of a multicast session transmits data packets at a fixed rate on each layer, while receivers each obtain different throughput by cumulatively subscribing to deferent number of layers based on their expected rates. In order to provide TCP-friendliness and estimate the expected rate accurately, a window-based mechanism implemented at receivers is presented. To achieve this, each receiver maintains a congestion window, adjusts it based on the GAIMD algorithm, and from the congestion window an expected rate is calculated. To measure RTT, a new method is presented which combines an accurate measurement with a rough estimation. A feedback suppression based on a random timer mechanism is given to avoid feedback implosion in the accurate measurement. The protocol is simple in its implementation. Simulations indicate that FLMCC shows good TCP-friendliness, responsiveness as well as intra-protocol fairness, and provides high link utilization.

  11. Chronic Pelvic Pain due to Pelvic Congestion Syndrome: The Role of Diagnostic and Interventional Radiology

    SciTech Connect

    Ganeshan, Arul; Upponi, Sara; Hon, Lye-Quen; Uthappa, M. C.; Warakaulle, Dinuke R.; Uberoi, Raman

    2007-11-15

    Chronic pelvic pain (CPP) is a common cause of gynecologic referral. Pelvic congestion syndrome, which is said to occurs due to ovarian vein incompetence, is a recognized cause of CPP. The aim of this paper is to briefly describe the clinical manifestations, and to review the role of diagnostic and interventional radiology in the management of this probably under-diagnosed condition.

  12. Congestion Management Requirements, Methods and Performance Indices

    SciTech Connect

    Kirby, B.J.

    2002-08-28

    Transmission congestion occurs when there is insufficient transmission capacity to simultaneously accommodate all requests for transmission service within a region. Historically, vertically integrated utilities managed this condition by constraining the economic dispatch of generators with the objective of ensuring security and reliability of their own and/or neighboring systems. Electric power industry restructuring has moved generation investment and operations decisions into the competitive market but has left transmission as a communal resource in the regulated environment. This mixing of competitive generation and regulated transmission makes congestion management difficult. The difficulty is compounded by increases in the amount of congestion resulting from increased commercial transactions and the relative decline in the amount of transmission. Transmission capacity, relative to peak load, has been declining in all regions of the U.S. for over a decade. This decline is expected to continue. Congestion management schemes used today have negative impacts on energy markets, such as disruptions and monetary penalties, under some conditions. To mitigate these concerns various congestion management methods have been proposed, including redispatch and curtailment of scheduled energy transmission. In the restructured electric energy industry environment, new congestion management approaches are being developed that strive to achieve the desired degree of reliability while supporting competition in the bulk power market. This report first presents an overview and background on key issues and emerging approaches to congestion management. It goes on to identify and describe policies affecting congestion management that are favored and/or are now being considered by FERC, NERC, and one of the regional reliability councils (WSCC). It reviews the operational procedures in use or proposed by three of the leading independent system operators (ISOs) including ERCOT

  13. Potassium induced cardiac standstill during conventional cardiopulmonary resuscitation in a pig model of prolonged ventricular fibrillation cardiac arrest: a feasibility study.

    PubMed

    Lee, Hyoung Youn; Lee, Byung Kook; Jeung, Kyung Woon; Lee, Sung Min; Jung, Yong Hun; Lee, Geo Sung; Heo, Tag; Min, Yong Il

    2013-03-01

    Potassium-based cardioplegia has been the gold standard for cardioprotection during cardiac surgery. We sought to evaluate the feasibility and the effects of potassium-induced cardiac standstill during conventional cardiopulmonary resuscitation (CPR) in a pig model of prolonged ventricular fibrillation (VF). VF was induced in 20 pigs, and circulatory arrest was maintained for 14 min. Animals were then resuscitated by standard CPR. Coincident with the start of CPR, 20 ml of saline (control group) or 0.9 mequiv.kg(-1) of potassium chloride diluted to 20 ml (potassium group) was administered into right atrium. Administration of potassium resulted in asystole lasting for 1.0 min (0.2) in the potassium group animals. VF reappeared in all but one animal, in which wide QRS complex bradycardia followed. Restoration of spontaneous circulation (ROSC) was attained in two animals (20%) in the control group and in seven animals (70%) in the potassium group (p=0.070). Resuscitated animals in the potassium group required fewer countershocks (3, 4 vs. 2 (1-2)), smaller doses of adrenaline (1.84, 1.84 vs. 0.94 (0.90-1.00)mg), and shorter duration of CPR (8, 10 vs. 4.0 (4.0-4.0)min) than did the control group. Potassium concentrations normalised rapidly after ROSC in both groups, and the potassium concentrations at 5 min (5.5, 6.6 vs. 6.8 (6.5-7.8)mequiv.l(-1)) and 4h (4.9, 5.4 vs. 5.9 (5.1-6.4)mequiv.l(-1)) after ROSC were similar in the both groups. In a pig model of untreated VF cardiac arrest for 14 min, resuscitation with potassium-induced cardiac standstill during conventional CPR was found to be feasible. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  14. Mean Field Type Control with Congestion

    SciTech Connect

    Achdou, Yves Laurière, Mathieu

    2016-06-15

    We analyze some systems of partial differential equations arising in the theory of mean field type control with congestion effects. We look for weak solutions. Our main result is the existence and uniqueness of suitably defined weak solutions, which are characterized as the optima of two optimal control problems in duality.

  15. Priority Based Congestion Control Dynamic Clustering Protocol in Mobile Wireless Sensor Networks

    PubMed Central

    Beulah Jayakumari, R.; Jawahar Senthilkumar, V.

    2015-01-01

    Wireless sensor network is widely used to monitor natural phenomena because natural disaster has globally increased which causes significant loss of life, economic setback, and social development. Saving energy in a wireless sensor network (WSN) is a critical factor to be considered. The sensor nodes are deployed to sense, compute, and communicate alerts in a WSN which are used to prevent natural hazards. Generally communication consumes more energy than sensing and computing; hence cluster based protocol is preferred. Even with clustering, multiclass traffic creates congested hotspots in the cluster, thereby causing packet loss and delay. In order to conserve energy and to avoid congestion during multiclass traffic a novel Priority Based Congestion Control Dynamic Clustering (PCCDC) protocol is developed. PCCDC is designed with mobile nodes which are organized dynamically into clusters to provide complete coverage and connectivity. PCCDC computes congestion at intra- and intercluster level using linear and binary feedback method. Each mobile node within the cluster has an appropriate queue model for scheduling prioritized packet during congestion without drop or delay. Simulation results have proven that packet drop, control overhead, and end-to-end delay are much lower in PCCDC which in turn significantly increases packet delivery ratio, network lifetime, and residual energy when compared with PASCC protocol. PMID:26504898

  16. Priority Based Congestion Control Dynamic Clustering Protocol in Mobile Wireless Sensor Networks.

    PubMed

    Jayakumari, R Beulah; Senthilkumar, V Jawahar

    2015-01-01

    Wireless sensor network is widely used to monitor natural phenomena because natural disaster has globally increased which causes significant loss of life, economic setback, and social development. Saving energy in a wireless sensor network (WSN) is a critical factor to be considered. The sensor nodes are deployed to sense, compute, and communicate alerts in a WSN which are used to prevent natural hazards. Generally communication consumes more energy than sensing and computing; hence cluster based protocol is preferred. Even with clustering, multiclass traffic creates congested hotspots in the cluster, thereby causing packet loss and delay. In order to conserve energy and to avoid congestion during multiclass traffic a novel Priority Based Congestion Control Dynamic Clustering (PCCDC) protocol is developed. PCCDC is designed with mobile nodes which are organized dynamically into clusters to provide complete coverage and connectivity. PCCDC computes congestion at intra- and intercluster level using linear and binary feedback method. Each mobile node within the cluster has an appropriate queue model for scheduling prioritized packet during congestion without drop or delay. Simulation results have proven that packet drop, control overhead, and end-to-end delay are much lower in PCCDC which in turn significantly increases packet delivery ratio, network lifetime, and residual energy when compared with PASCC protocol.

  17. Delivering Faster Congestion Feedback with the Mark-Front Strategy

    NASA Technical Reports Server (NTRS)

    Liu, Chunlei; Jain, Raj

    2001-01-01

    Computer networks use congestion feedback from the routers and destinations to control the transmission load. Delivering timely congestion feedback is essential to the performance of networks. Reaction to the congestion can be more effective if faster feedback is provided. Current TCP/IP networks use timeout, duplicate Acknowledgement Packets (ACKs) and explicit congestion notification (ECN) to deliver the congestion feedback, each provides a faster feedback than the previous method. In this paper, we propose a markfront strategy that delivers an even faster congestion feedback. With analytical and simulation results, we show that mark-front strategy reduces buffer size requirement, improves link efficiency and provides better fairness among users. Keywords: Explicit Congestion Notification, mark-front, congestion control, buffer size requirement, fairness.

  18. Microscopic theory of spatial-temporal congested traffic patterns at highway bottlenecks

    NASA Astrophysics Data System (ADS)

    Kerner, Boris S.; Klenov, Sergey L.

    2003-09-01

    at the upstream bottleneck (the catch effect). MSP, WSP, or wide moving jams first emerged at the downstream bottleneck induce diverse patterns at the upstream bottleneck. The onset of congestion at the upstream bottleneck can lead to an intensification of congestion at the downstream bottleneck. This causes a change in the pattern type and/or the pattern features.

  19. Microscopic theory of spatial-temporal congested traffic patterns at highway bottlenecks.

    PubMed

    Kerner, Boris S; Klenov, Sergey L

    2003-09-01

    upstream bottleneck (the catch effect). MSP, WSP, or wide moving jams first emerged at the downstream bottleneck induce diverse patterns at the upstream bottleneck. The onset of congestion at the upstream bottleneck can lead to an intensification of congestion at the downstream bottleneck. This causes a change in the pattern type and/or the pattern features.

  20. Pharmacotherapy in congestive heart failure: ACE inhibitors and anemia in congestive heart failure.

    PubMed

    Sica, D S

    2000-01-01

    The use of angiotensin-converting enzyme inhibitors can be accompanied by a number of adverse events, including cough, angioedema, and hyperkalemia, as well as a peculiar form of functional renal insufficiency. Other, less obvious side effects accompany ACE inhibitor use, such as a reduction in red blood cell production. This feature of ACE inhibitor use may be employed to good effect, as in the management of post-transplant erythrocytosis. Alternatively, the suppressive effect of ACE inhibitors on red blood cell production may intensify the anemia of chronic renal failure and/or congestive heart failure. The untreated congestive heart failure patient typically has an increased red blood cell mass as a consequence of increased erythropoietin levels, with the latter governed by congestive heart failure-related renal hypoxia. This is not expressed as an increase in hemoglobin concentration because of the increase in plasma volume that marks advanced congestive heart failure. ACE inhibitor therapy can be expected to both reduce plasma volume and decrease red blood cell production. As a result, the hemoglobin concentration changes very little in the ACE inhibitor-treated congestive heart failure patient and usually falls in the low normal range. Recently, erythropoietin has been employed to good effect in congestive heart failure patients with borderline anemia. (c)2000 by CHF, Inc.

  1. Adaptive-compression based congestion control technique for wireless sensor networks.

    PubMed

    Lee, Joa-Hyoung; Jung, In-Bum

    2010-01-01

    Congestion in a wireless sensor network causes an increase in the amount of data loss and delays in data transmission. In this paper, we propose a new congestion control technique (ACT, Adaptive Compression-based congestion control Technique) based on an adaptive compression scheme for packet reduction in case of congestion. The compression techniques used in the ACT are Discrete Wavelet Transform (DWT), Adaptive Differential Pulse Code Modulation (ADPCM), and Run-Length Coding (RLC). The ACT first transforms the data from the time domain to the frequency domain, reduces the range of data by using ADPCM, and then reduces the number of packets with the help of RLC before transferring the data to the source node. It introduces the DWT for priority-based congestion control because the DWT classifies the data into four groups with different frequencies. The ACT assigns priorities to these data groups in an inverse proportion to the respective frequencies of the data groups and defines the quantization step size of ADPCM in an inverse proportion to the priorities. RLC generates a smaller number of packets for a data group with a low priority. In the relaying node, the ACT reduces the amount of packets by increasing the quantization step size of ADPCM in case of congestion. Moreover, in order to facilitate the back pressure, the queue is controlled adaptively according to the congestion state. We experimentally demonstrate that the ACT increases the network efficiency and guarantees fairness to sensor nodes, as compared with the existing methods. Moreover, it exhibits a very high ratio of the available data in the sink.

  2. Adaptive-Compression Based Congestion Control Technique for Wireless Sensor Networks

    PubMed Central

    Lee, Joa-Hyoung; Jung, In-Bum

    2010-01-01

    Congestion in a wireless sensor network causes an increase in the amount of data loss and delays in data transmission. In this paper, we propose a new congestion control technique (ACT, Adaptive Compression-based congestion control Technique) based on an adaptive compression scheme for packet reduction in case of congestion. The compression techniques used in the ACT are Discrete Wavelet Transform (DWT), Adaptive Differential Pulse Code Modulation (ADPCM), and Run-Length Coding (RLC). The ACT first transforms the data from the time domain to the frequency domain, reduces the range of data by using ADPCM, and then reduces the number of packets with the help of RLC before transferring the data to the source node. It introduces the DWT for priority-based congestion control because the DWT classifies the data into four groups with different frequencies. The ACT assigns priorities to these data groups in an inverse proportion to the respective frequencies of the data groups and defines the quantization step size of ADPCM in an inverse proportion to the priorities. RLC generates a smaller number of packets for a data group with a low priority. In the relaying node, the ACT reduces the amount of packets by increasing the quantization step size of ADPCM in case of congestion. Moreover, in order to facilitate the back pressure, the queue is controlled adaptively according to the congestion state. We experimentally demonstrate that the ACT increases the network efficiency and guarantees fairness to sensor nodes, as compared with the existing methods. Moreover, it exhibits a very high ratio of the available data in the sink. PMID:22319280

  3. 75 FR 22770 - National Electric Transmission Congestion Study

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-30

    ... National Electric Transmission Congestion Study AGENCY: Office of Electricity Delivery and Energy Reliability (OE), Department of Energy. ACTION: Notice of Availability of 2009 National Electric Transmission... notice that it has issued a National Electric Transmission Congestion Study (2009 Congestion Study) and...

  4. Airport Characterization for the Adaptation of Surface Congestion Management Approaches

    DTIC Science & Technology

    2013-02-01

    1 of 2 Airport Characterization for the Adaptation of Surface Congestion Management Approaches Melanie Sandberg, Tom Reynolds...TYPE 3. DATES COVERED 00-00-2013 to 00-00-2013 4. TITLE AND SUBTITLE Airport Characterization for the Adaptation of Surface Congestion Management...1 Airport Characterization for the Adaptation of Surface Congestion Management Approaches* Melanie

  5. Auctionable fixed transmission rights for congestion management

    NASA Astrophysics Data System (ADS)

    Alomoush, Muwaffaq Irsheid

    Electric power deregulation has proposed a major change to the regulated utility monopoly. The change manifests the main part of engineers' efforts to reshape three components of today's regulated monopoly: generation, distribution and transmission. In this open access deregulated power market, transmission network plays a major role, and transmission congestion is a major problem that requires further consideration especially when inter-zonal/intra-zonal scheme is implemented. Declaring that engineering studies and experience are the criteria to define zonal boundaries or defining a zone based on the fact that a zone is a densely interconnected area (lake) and paths connecting these densely interconnected areas are inter-zonal lines will render insufficient and fuzzy definitions. Moreover, a congestion problem formulation should take into consideration interactions between intra-zonal and inter-zonal flows and their effects on power systems. In this thesis, we introduce a procedure for minimizing the number of adjustments of preferred schedules to alleviate congestion and apply control schemes to minimize interactions between zones. In addition, we give the zone definition a certain criterion based on the Locational Marginal Price (LMP). This concept will be used to define congestion zonal boundaries and to decide whether any zone should be merged with another zone or split into new zones. The thesis presents a unified scheme that combines zonal and FTR schemes to manage congestion. This combined scheme is utilized with LMPs to define zonal boundaries more appropriately. The presented scheme gains the best features of the FTR scheme, which are providing financial certainty, maximizing the efficient use of the system and making users pay for the actual use of congested paths. LMPs may give an indication of the impact of wheeling transactions, and calculations of and comparisons of LMPs with and without wheeling transactions should be adequate criteria to approve

  6. Improving Explicit Congestion Notification with the Mark-Front Strategy

    NASA Technical Reports Server (NTRS)

    Liu, Chunlei; Jain, Raj

    2001-01-01

    Delivering congestion signals is essential to the performance of networks. Current TCP/IP networks use packet losses to signal congestion. Packet losses not only reduces TCP performance, but also adds large delay. Explicit Congestion Notification (ECN) delivers a faster indication of congestion and has better performance. However, current ECN implementations mark the packet from the tail of the queue. In this paper, we propose the mark-front strategy to send an even faster congestion signal. We show that mark-front strategy reduces buffer size requirement, improves link efficiency and provides better fairness among users. Simulation results that verify our analysis are also presented.

  7. Effect of telemonitoring on re-admission in patients with congestive heart failure.

    PubMed

    Smith, Amy Christine

    2013-01-01

    Interest in telemonitoring interventions to reduce re-admissions in patients with congestive heart failure (CHF) is growing. This critical review of available evidence suggests telemonitoring may reduce CHF-related re-admissions, although a clear impact on all-cause re-admissions remains elusive.

  8. Pericardial and pleural effusions in congestive heart failure-anatomical, pathophysiologic, and clinical considerations.

    PubMed

    Natanzon, Alex; Kronzon, Itzhak

    2009-09-01

    Transudative pleural and pericardial effusions are not uncommon in patients with congestive heart failure. Pericardial effusion forms only with elevation of the right-sided filling pressure in the heart. In patients with biventricular failure, there is no evidence that elevated left-sided pressure, in the absence of elevated right-sided pressure, can cause a pericardial effusion. Pleural effusion forms with acute elevation of the right-sided or the left-sided filling pressure in the heart. In patients with congestive heart failure, elevated right-sided filling pressures are less common than elevated left-sided filling pressures, thus, explaining a lower prevalence of pericardial than pleural effusions. Pleural effusions in patients with congestive heart failure are typically bilateral. However, a unilateral pleural effusion is more commonly seen on the right side. Although multiple theories attempt to explain the right-sided preponderance of pleural effusion, to date, no mechanism has been universally accepted or experimentally proven.

  9. Can complexity decrease in congestive heart failure?

    NASA Astrophysics Data System (ADS)

    Mukherjee, Sayan; Palit, Sanjay Kumar; Banerjee, Santo; Ariffin, M. R. K.; Rondoni, Lamberto; Bhattacharya, D. K.

    2015-12-01

    The complexity of a signal can be measured by the Recurrence period density entropy (RPDE) from the reconstructed phase space. We have chosen a window based RPDE method for the classification of signals, as RPDE is an average entropic measure of the whole phase space. We have observed the changes in the complexity in cardiac signals of normal healthy person (NHP) and congestive heart failure patients (CHFP). The results show that the cardiac dynamics of a healthy subject is more complex and random compare to the same for a heart failure patient, whose dynamics is more deterministic. We have constructed a general threshold to distinguish the border line between a healthy and a congestive heart failure dynamics. The results may be useful for wide range for physiological and biomedical analysis.

  10. Compression treatment of pelvic congestion syndrome.

    PubMed

    Gavrilov, S G; Karalkin, A V; Turischeva, O O

    2017-01-01

    Aim To study the influence of compression treatment on clinical manifestations and venous hemodynamics of the pelvis in patients with pelvic congestion syndrome. Materials and methods A prospective study of the various options and modes of compression treatment was carried out and included 74 patients with pelvic congestion syndrome in 2008-2015. The patients were divided into three groups. The first group consisted of 48 patients with symptoms of pelvic congestion syndrome and chronic pelvic pain. They used Class II compression shorts. In the second group, there were 14 patients with pelvic congestion syndrome, vulvar varicosities without pelvic pain. They used Class II compression shorts and stockings. In the third group, 12 women with pelvic congestion syndrome and chronic pelvic pain used only the Class II compression stockings. The treatment continued for 14 days. A clinical criterion was the change of severity of chronic pelvic pain. The evaluation of the treatments has been performed using radionuclide venography and emission computed tomography with labeled in vivo red blood cells. Results Group 1: The compression shorts had a positive effect on the disease in 81.3% of patients. Chronic pelvic pain decreased from 6.4 ± 1.6 to 1.2 ± 0.7 points. The coefficient of pelvic congestion syndrome (Cpcs) decreased from 1.73 ± 0.32 to 1.12 ± 0.27 (p < 0.05). In 18.8% of patients, no positive effect was observed. Group 2: The results of radionuclide venographyshowed accelerating outflow of blood from the lower limbs and reduction of insufficiency of perforating veins. Mean radionuclide transit time decreased in all patients in the tendon, muscle pump parts, popliteal vein and was respectively: 23.6 ± 2.2 s, 29.6 ± 3.4 s, 32.3 ± 4.2 s and after treatment 16.4 ± 3.1 s, 22.1 ± 2.5 s, 25.7 ± 1.9 s (p < 0.05). Group 3: The use of compression stockings class II on the clinical manifestations of pelvic

  11. Abdominal contributions to cardiorenal dysfunction in congestive heart failure.

    PubMed

    Verbrugge, Frederik H; Dupont, Matthias; Steels, Paul; Grieten, Lars; Malbrain, Manu; Tang, W H Wilson; Mullens, Wilfried

    2013-08-06

    Current pathophysiological models of congestive heart failure unsatisfactorily explain the detrimental link between congestion and cardiorenal function. Abdominal congestion (i.e., splanchnic venous and interstitial congestion) manifests in a substantial number of patients with advanced congestive heart failure, yet is poorly defined. Compromised capacitance function of the splanchnic vasculature and deficient abdominal lymph flow resulting in interstitial edema might both be implied in the occurrence of increased cardiac filling pressures and renal dysfunction. Indeed, increased intra-abdominal pressure, as an extreme marker of abdominal congestion, is correlated with renal dysfunction in advanced congestive heart failure. Intriguing findings provide preliminary evidence that alterations in the liver and spleen contribute to systemic congestion in heart failure. Finally, gut-derived hormones might influence sodium homeostasis, whereas entrance of bowel toxins into the circulatory system, as a result of impaired intestinal barrier function secondary to congestion, might further depress cardiac as well as renal function. Those toxins are mainly produced by micro-organisms in the gut lumen, with presumably important alterations in advanced heart failure, especially when renal function is depressed. Therefore, in this state-of-the-art review, we explore the crosstalk between the abdomen, heart, and kidneys in congestive heart failure. This might offer new diagnostic opportunities as well as treatment strategies to achieve decongestion in heart failure, especially when abdominal congestion is present. Among those currently under investigation are paracentesis, ultrafiltration, peritoneal dialysis, oral sodium binders, vasodilator therapy, renal sympathetic denervation and agents targeting the gut microbiota.

  12. Cardiac CT Angiography in Congestive Heart Failure.

    PubMed

    Levine, Avi; Hecht, Harvey S

    2015-06-01

    Cardiac CT angiography has become an important tool for the diagnosis and treatment of congestive heart failure. Differentiation of ischemic from nonischemic cardiomyopathy; evaluation of myocardial perfusion; characterization of hypertrophic cardiomyopathy, left ventricular noncompaction, and arrhythmogenic right ventricular dysplasia; and delineation of congenital heart defects and valvular abnormalities are the primary diagnostic applications. Therapeutic use includes visualization of the coronary venous anatomy for optimal implementation of cardiac resynchronization therapy and evaluation of left ventricular assist devices and transplant vasculopathy.

  13. Onset of traffic congestion in complex networks.

    PubMed

    Zhao, Liang; Lai, Ying-Cheng; Park, Kwangho; Ye, Nong

    2005-02-01

    Free traffic flow on a complex network is key to its normal and efficient functioning. Recent works indicate that many realistic networks possess connecting topologies with a scale-free feature: the probability distribution of the number of links at nodes, or the degree distribution, contains a power-law component. A natural question is then how the topology influences the dynamics of traffic flow on a complex network. Here we present two models to address this question, taking into account the network topology, the information-generating rate, and the information-processing capacity of individual nodes. For each model, we study four kinds of networks: scale-free, random, and regular networks and Cayley trees. In the first model, the capacity of packet delivery of each node is proportional to its number of links, while in the second model, it is proportional to the number of shortest paths passing through the node. We find, in both models, that there is a critical rate of information generation, below which the network traffic is free but above which traffic congestion occurs. Theoretical estimates are given for the critical point. For the first model, scale-free networks and random networks are found to be more tolerant to congestion. For the second model, the congestion condition is independent of network size and topology, suggesting that this model may be practically useful for designing communication protocols.

  14. Congestion Pricing for Aircraft Pushback Slot Allocation.

    PubMed

    Liu, Lihua; Zhang, Yaping; Liu, Lan; Xing, Zhiwei

    2017-01-01

    In order to optimize aircraft pushback management during rush hour, aircraft pushback slot allocation based on congestion pricing is explored while considering monetary compensation based on the quality of the surface operations. First, the concept of the "external cost of surface congestion" is proposed, and a quantitative study on the external cost is performed. Then, an aircraft pushback slot allocation model for minimizing the total surface cost is established. An improved discrete differential evolution algorithm is also designed. Finally, a simulation is performed on Xinzheng International Airport using the proposed model. By comparing the pushback slot control strategy based on congestion pricing with other strategies, the advantages of the proposed model and algorithm are highlighted. In addition to reducing delays and optimizing the delay distribution, the model and algorithm are better suited for use for actual aircraft pushback management during rush hour. Further, it is also observed they do not result in significant increases in the surface cost. These results confirm the effectiveness and suitability of the proposed model and algorithm.

  15. Dynamic congestion control mechanisms for MPLS networks

    NASA Astrophysics Data System (ADS)

    Holness, Felicia; Phillips, Chris I.

    2001-02-01

    Considerable interest has arisen in congestion control through traffic engineering from the knowledge that although sensible provisioning of the network infrastructure is needed, together with sufficient underlying capacity, these are not sufficient to deliver the Quality of Service required for new applications. This is due to dynamic variations in load. In operational Internet Protocol (IP) networks, it has been difficult to incorporate effective traffic engineering due to the limited capabilities of the IP technology. In principle, Multiprotocol Label Switching (MPLS), which is a connection-oriented label swapping technology, offers new possibilities in addressing the limitations by allowing the operator to use sophisticated traffic control mechanisms. This paper presents a novel scheme to dynamically manage traffic flows through the network by re-balancing streams during periods of congestion. It proposes management-based algorithms that will allow label switched routers within the network to utilize mechanisms within MPLS to indicate when flows are starting to experience frame/packet loss and then to react accordingly. Based upon knowledge of the customer's Service Level Agreement, together with instantaneous flow information, the label edge routers can then instigate changes to the LSP route and circumvent congestion that would hitherto violate the customer contacts.

  16. Pulmonary congestion evaluated by lung ultrasound predicts decompensation in heart failure outpatients.

    PubMed

    Miglioranza, Marcelo H; Picano, Eugenio; Badano, Luigi P; Sant'Anna, Roberto; Rover, Marciane; Zaffaroni, Facundo; Sicari, Rosa; Kalil, Renato K; Leiria, Tiago L; Gargani, Luna

    2017-08-01

    Pulmonary congestion is the main cause of hospital admission among heart failure (HF) patients. Lung ultrasound (LUS) assessment of B-lines has been recently proposed as a reliable and easy tool for evaluating pulmonary congestion. To determine the prognostic value of LUS in predicting adverse events in HF outpatients. Single-center prospective cohort of 97 moderate-to-severe systolic HF patients (53±13years; 61% males) consecutively enrolled between November 2011 and October 2012. LUS evaluation was performed during the regular outpatient visit to evaluate the presence of pulmonary congestion, determined by B-lines number. Patients were followed up for 4months to assess admission due to acute pulmonary edema. During follow-up period (106±12days), 21 hospitalizations for acute pulmonary edema occurred. At Cox regression analysis, B-lines number≥30 (HR 8.62; 95%CI: 1.8-40.1; p=0.006) identified a group at high risk for acute pulmonary edema admission at 120days, and was the strongest predictor of events compared to other established clinical, laboratory and instrumental findings. No acute pulmonary edema occurred in patients without significant pulmonary congestion at LUS (number of B-lines<15). In a HF outpatient setting, B-line assessment by LUS identifies patients more likely to be admitted for decompensated HF in the following 4months. This simple evaluation could allow prompt therapy optimization in those patients who, although asymptomatic, carry a significant degree of extravascular lung water. Pulmonary congestion is the main cause of hospital admissions among heart failure patients. Lung ultrasound can be used as a reliable and easy way to evaluate pulmonary congestion through assessment of B-lines. In a cohort of heart failure outpatients, a B-lines cutoff≥30 (HR 8.62; 95%CI: 1.8-40.1) identified patients most likely to develop acute pulmonary edema at 120-days. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. [Juvenile haemochromatosis presenting as intractable congestive heart failure].

    PubMed

    Vas, Katalin; Hubay, Marta; Tordai, Attila; Andrikovics, Hajnalka; Zoltán, Sápi; Jánosi, András

    2005-12-18

    Juvenile haemochromatosis is an autosomal, recessive inherited iron metabolism disorder. The rapid deterioration and malignant prognosis differentiate juvenile haemochromatosis from hereditary haemochromatosis. The authors summarize the history of a 25 year old man, who worked in Hungary as a guest worker living in Romania. No significant illness has occurred in his previous history. The abdominal pain was his first symptom and he was treated in different institutions, where cholecystitis, alcoholic hepatic disease, hepatic cirrhosis were considered as a cause of his symptoms. Some weeks later atrial tachycardia, and congestive heart failure were observed and he was sent to our Cardiology Department. The echocardiography revealed diffuse hypokinesis, serious systolic dysfunction (ejection fraction: 21%), grade II mitral and tricuspid insufficiency with pulmonary hypertension. Considering the rapid deterioration of his cardiac function, myocarditis was suspected. Myocardial biopsy and coronary arteriography were performed. Coronary arteries were normal. Ventricular fibrillation occurred during coronary arteriography. Myocardial biopsy revealed juvenile haemochromatosis. Special laboratory examinations (transferrin saturation) were made after biopsy, that also confirmed the diagnosis of juvenile haemochromatosis. Cardiac transplantation was planned. Some days after the diagnosis was made the patient died of cardiogenic shock and intractable heart failure. Autopsy revealed hypogonadism and serious haemochromatosis in different parenchymal organs. Juvenile haemochromatosis should be considered in every young patient with congestive heart failure of unknown etiology.

  18. Congestion control and routing over satellite networks

    NASA Astrophysics Data System (ADS)

    Cao, Jinhua

    Satellite networks and transmissions find their application in fields of computer communications, telephone communications, television broadcasting, transportation, space situational awareness systems and so on. This thesis mainly focuses on two networking issues affecting satellite networking: network congestion control and network routing optimization. Congestion, which leads to long queueing delays, packet losses or both, is a networking problem that has drawn the attention of many researchers. The goal of congestion control mechanisms is to ensure high bandwidth utilization while avoiding network congestion by regulating the rate at which traffic sources inject packets into a network. In this thesis, we propose a stable congestion controller using data-driven, safe switching control theory to improve the dynamic performance of satellite Transmission Control Protocol/Active Queue Management (TCP/AQM) networks. First, the stable region of the Proportional-Integral (PI) parameters for a nominal model is explored. Then, a PI controller, whose parameters are adaptively tuned by switching among members of a given candidate set, using observed plant data, is presented and compared with some classical AQM policy examples, such as Random Early Detection (RED) and fixed PI control. A new cost detectable switching law with an interval cost function switching algorithm, which improves the performance and also saves the computational cost, is developed and compared with a law commonly used in the switching control literature. Finite-gain stability of the system is proved. A fuzzy logic PI controller is incorporated as a special candidate to achieve good performance at all nominal points with the available set of candidate controllers. Simulations are presented to validate the theory. An effocient routing algorithm plays a key role in optimizing network resources. In this thesis, we briefly analyze Low Earth Orbit (LEO) satellite networks, review the Cross Entropy (CE

  19. Determination of the model parameters of machines from the reactance operators x[sub d](p), x[sub q](p) (Evaluation of standstill frequency response test)

    SciTech Connect

    Canay, I.M. )

    1993-06-01

    A method is presented for determining the characteristic quantities and model parameters from the given frequency responses x[sub d](js), x[sub q](js). The curves of values measured on a large turbogenerator at standstill are used as an example. The characteristic values and model parameters are determined for various models (with 4, 3 and 2 rotor circuits in each axis) and are compared with the results of the short-circuit tests and with advance calculations.

  20. [The role of the computed tomography in the identification of the syndrome of pelvic congestion].

    PubMed

    Motta-Ramírez, Gaspar Alberto; Ruiz-Castro, Eloise; Torres-Hernández, Verónica; Herrera-Avilés, Ricardo Arturo; Rodríguez-Treviño, Carlos

    2013-07-01

    Pelvic congestion syndrome is a condition not yet fully understood, hence provokes controversy. It is cause of up to 40% of visits to the doctor; affecting women of reproductive age who experience non-specific symptoms such as characteristic pelvic pain with more than six months of evolution and difficult to treat dyspareunia in which even narcotics are insufficient for control. To recognize the vascular anatomy of the pelvic cavity and identify the characteristics of pelvic congestion syndrome demonstrable by computed tomography. A descriptive, observational, cross-sectional and retrospective study at Hospital Angeles del Pedregal, in the Department of Radiology and Imaging with patients who reported imaging studies with key findings to recognize the pelvic congestion syndrome. All women with incidental finding of abnormal dilation of the gonadal vein were included, allowing to suggest pelvic congestion syndrome as a possible diagnosis. There were 17 cases (0.9%) of patients with abdominopelvic pain syndrome who underwent multislice computed tomography to 3 mm, with extension from the lung bases to the pubic symphysis. Predominance of left gonadal vein is conditioned by the anatomical arrangement of the left gonadal vein. During the arterial phase opacification of the gonadal vein was identified in 11 patients (65%), a circumstance that correlates with retrograde venous flow valve incompetence. In computed tomography findings of pelvic congestion syndrome were also identified 12 patients (70%) with abdominopelvic pain syndrome. Pelvic congestion syndrome is a rare condition that radiologists do not consider because they don't know it and the clinical diagnoses give no clinical data to suggest this condition. But if one takes into account the literature, it refers to it as the origin of up to 40% of the visits to the gynecologist, and there may be more cases that will increase its prevalence.

  1. Respiratory sleep disorders in patients with congestive heart failure.

    PubMed

    Naughton, Matthew T

    2015-08-01

    Respiratory sleep disorders (RSD) occur in about 40-50% of patients with symptomatic congestive heart failure (CHF). Obstructive sleep apnea (OSA) is considered a cause of CHF, whereas central sleep apnea (CSA) is considered a response to heart failure, perhaps even compensatory. In the setting of heart failure, continuous positive airway pressure (CPAP) has a definite role in treating OSA with improvements in cardiac parameters expected. However in CSA, CPAP is an adjunctive therapy to other standard therapies directed towards the heart failure (pharmacological, device and surgical options). Whether adaptive servo controlled ventilatory support, a variant of CPAP, is beneficial is yet to be proven. Supplemental oxygen therapy should be used with caution in heart failure, in particular, by avoiding hyperoxia as indicated by SpO2 values >95%.

  2. Congestion Measures for Organized Markets in the U.S.

    SciTech Connect

    Fisher, Emily; Eto, Joseph H.

    2013-12-16

    Transmission lines deliver electricity that is generated at power plants to loads. When there is not sufficient transmission capacity to schedule or transport all desired electricity transfers, the transmission system is constrained, and the particular line, flowgate or interface is congested. While it is useful to measure congestion for several reasons—to identify where and how much congestion exists and how this changes over time, to determine whether or what to do about it, and to assess the effectiveness of actions taken—it is challenging to measure congestion in a meaningful and consistent way across markets or over time in the same market. This paper examines current public reporting of congestion measures for organized markets in the U.S., and what these measures can and cannot tell us about congestion across regions or over time in the same region.

  3. Prehospital management of congestive heart failure.

    PubMed

    Mattu, Amal; Lawner, Benjamin

    2009-01-01

    The evolution of prehospital treatment of decompensated congestive heart failure has in some ways come full circle: rather than emphasizing a battery of new pharmacotherapies, out-of-hospital providers have a renewed focus on aggressive use of nitrates, optimization of airway support, and rapid transport. The use of furosemide and morphine has become de-emphasized, and a flurry of research activity and excitement revolves around the use of noninvasive positive-pressure ventilation. Further research will clarify the role of bronchodilators and angiotensin-converting enzyme inhibitors in the prehospital setting.

  4. Traffic Congestion Model: Challenges and Opportunities

    NASA Astrophysics Data System (ADS)

    Enjat Munajat, M. D.; Munir, Rinaldi; Widyantoro, Dwi H.

    2017-01-01

    This paper discusses models to detect traffic congestion using two approaches: road detection and moving object detection. There are two methods proposed to detect roads and moving objects. The methods involve the detection of both moving and non-moving objects. The system presented in this paper is able to detect roads as well as moving objects. However, further development is needed to detect extreme road curves. The system presented in this paper is relatively inexpensive since it only uses one camera and capable of capturing satisfactorily detailed images.

  5. Modeling congestion on urban roads and assessing level of service

    SciTech Connect

    Maitra, B.; Sikdar, P.K.; Dhingra, S.L.

    1999-12-01

    A unified methodology has been proposed for the quantification of congestion, incorporating the volume and operational characteristics of traffic movement. The level of congestion has been modeled to relate to the causal influences of traffic movement. Modeling congestion has provided a quantitative basis for understanding the contribution of different vehicle types in overall congestion, and it is useful for evolving the policy for congestion mitigation. Quantified congestion level has been used as a logical and improved measure of effectiveness to account for the conceptual definition of level of service in a quantitative manner. Based on the congestion level, 10 levels of service have been proposed, with 9 in stable flow zone (presently designated as A-E), and 1 representing an unstable operation (presently designated as F). The philosophy has been demonstrated by developing congestion models and assessing the effect of roadway width on congestion levels and service volumes. While it is possible to assess the realized benefits from an increase in roadway width, the required number of traffic lanes for a desired level of service can also be estimated.

  6. Congestion Pricing for Aircraft Pushback Slot Allocation

    PubMed Central

    Zhang, Yaping

    2017-01-01

    In order to optimize aircraft pushback management during rush hour, aircraft pushback slot allocation based on congestion pricing is explored while considering monetary compensation based on the quality of the surface operations. First, the concept of the “external cost of surface congestion” is proposed, and a quantitative study on the external cost is performed. Then, an aircraft pushback slot allocation model for minimizing the total surface cost is established. An improved discrete differential evolution algorithm is also designed. Finally, a simulation is performed on Xinzheng International Airport using the proposed model. By comparing the pushback slot control strategy based on congestion pricing with other strategies, the advantages of the proposed model and algorithm are highlighted. In addition to reducing delays and optimizing the delay distribution, the model and algorithm are better suited for use for actual aircraft pushback management during rush hour. Further, it is also observed they do not result in significant increases in the surface cost. These results confirm the effectiveness and suitability of the proposed model and algorithm. PMID:28114429

  7. Adapting End Host Congestion Control for Mobility

    NASA Technical Reports Server (NTRS)

    Eddy, Wesley M.; Swami, Yogesh P.

    2005-01-01

    Network layer mobility allows transport protocols to maintain connection state, despite changes in a node's physical location and point of network connectivity. However, some congestion-controlled transport protocols are not designed to deal with these rapid and potentially significant path changes. In this paper we demonstrate several distinct problems that mobility-induced path changes can create for TCP performance. Our premise is that mobility events indicate path changes that require re-initialization of congestion control state at both connection end points. We present the application of this idea to TCP in the form of a simple solution (the Lightweight Mobility Detection and Response algorithm, that has been proposed in the IETF), and examine its effectiveness. In general, we find that the deficiencies presented are both relatively easily and painlessly fixed using this solution. We also find that this solution has the counter-intuitive property of being both more friendly to competing traffic, and simultaneously more aggressive in utilizing newly available capacity than unmodified TCP.

  8. Cross-layer active predictive congestion control protocol for wireless sensor networks.

    PubMed

    Wan, Jiangwen; Xu, Xiaofeng; Feng, Renjian; Wu, Yinfeng

    2009-01-01

    In wireless sensor networks (WSNs), there are numerous factors that may cause network congestion problems, such as the many-to-one communication modes, mutual interference of wireless links, dynamic changes of network topology and the memory-restrained characteristics of nodes. All these factors result in a network being more vulnerable to congestion. In this paper, a cross-layer active predictive congestion control scheme (CL-APCC) for improving the performance of networks is proposed. Queuing theory is applied in the CL-APCC to analyze data flows of a single-node according to its memory status, combined with the analysis of the average occupied memory size of local networks. It also analyzes the current data change trends of local networks to forecast and actively adjust the sending rate of the node in the next period. In order to ensure the fairness and timeliness of the network, the IEEE 802.11 protocol is revised based on waiting time, the number of the node's neighbors and the original priority of data packets, which dynamically adjusts the sending priority of the node. The performance of CL-APCC, which is evaluated by extensive simulation experiments. is more efficient in solving the congestion in WSNs. Furthermore, it is clear that the proposed scheme has an outstanding advantage in terms of improving the fairness and lifetime of networks.

  9. Cross-Layer Active Predictive Congestion Control Protocol for Wireless Sensor Networks

    PubMed Central

    Wan, Jiangwen; Xu, Xiaofeng; Feng, Renjian; Wu, Yinfeng

    2009-01-01

    In wireless sensor networks (WSNs), there are numerous factors that may cause network congestion problems, such as the many-to-one communication modes, mutual interference of wireless links, dynamic changes of network topology and the memory-restrained characteristics of nodes. All these factors result in a network being more vulnerable to congestion. In this paper, a cross-layer active predictive congestion control scheme (CL-APCC) for improving the performance of networks is proposed. Queuing theory is applied in the CL-APCC to analyze data flows of a single-node according to its memory status, combined with the analysis of the average occupied memory size of local networks. It also analyzes the current data change trends of local networks to forecast and actively adjust the sending rate of the node in the next period. In order to ensure the fairness and timeliness of the network, the IEEE 802.11 protocol is revised based on waiting time, the number of the node's neighbors and the original priority of data packets, which dynamically adjusts the sending priority of the node. The performance of CL-APCC, which is evaluated by extensive simulation experiments. is more efficient in solving the congestion in WSNs. Furthermore, it is clear that the proposed scheme has an outstanding advantage in terms of improving the fairness and lifetime of networks. PMID:22408506

  10. Pulmonary Congestion Predicts Cardiac Events and Mortality in ESRD

    PubMed Central

    Torino, Claudia; Tripepi, Rocco; Tripepi, Giovanni; D’Arrigo, Graziella; Postorino, Maurizio; Gargani, Luna; Sicari, Rosa; Picano, Eugenio; Mallamaci, Francesca

    2013-01-01

    Pulmonary congestion is highly prevalent and often asymptomatic among patients with ESRD treated with hemodialysis, but whether its presence predicts clinical outcomes is unknown. Here, we tested the prognostic value of extravascular lung water measured by a simple, well validated ultrasound B-lines score (BL-US) in a multicenter study that enrolled 392 hemodialysis patients. We detected moderate-to-severe lung congestion in 45% and very severe congestion in 14% of the patients. Among those patients with moderate-to-severe lung congestion, 71% were asymptomatic or presented slight symptoms of heart failure. Compared with those patients having mild or no congestion, patients with very severe congestion had a 4.2-fold risk of death (HR=4.20, 95% CI=2.45–7.23) and a 3.2-fold risk of cardiac events (HR=3.20, 95% CI=1.75–5.88) adjusted for NYHA class and other risk factors. Including the degree of pulmonary congestion in the model significantly improved the risk reclassification for cardiac events by 10% (P<0.015). In summary, lung ultrasound can detect asymptomatic pulmonary congestion in hemodialysis patients, and the resulting BL-US score is a strong, independent predictor of death and cardiac events in this population. PMID:23449536

  11. Driving with a Congestion Assistant; mental workload and acceptance.

    PubMed

    Brookhuis, Karel A; van Driel, Cornelie J G; Hof, Tineke; van Arem, Bart; Hoedemaeker, Marika

    2009-11-01

    New driver support systems are developed and introduced to the market at increasing speed. In conditions of traffic congestion drivers may be supported by a "Congestion Assistant", a system that combines the features of a Congestion Warning System (acoustic warning and gas pedal counterforce) and a Stop & Go system (automatic gas and brake pedal during congestion). To gain understanding of the effects of driving with a Congestion Assistant on drivers, mental workload of drivers was registered under different conditions as well as acceptance of the system. Mental workload was measured by means of physiological registrations, i.e. heart rate, a secondary task and with the aid of subjective scaling techniques. Acceptance was measured with an acceptance scale. The study was carried out in an advanced driving simulator. Driving with the Congestion Assistant while in congestion potentially leads to decreased driver mental workload, whereas just before congestion starts, i.e. developing just noticeable, the system may add to the workload of the driver. Acceptance is generally high after experiencing the system, though not in all respects.

  12. Stochastic Stability in Internet Router Congestion Games

    NASA Astrophysics Data System (ADS)

    Chung, Christine; Pyrga, Evangelia

    Congestion control at bottleneck routers on the internet is a long standing problem. Many policies have been proposed for effective ways to drop packets from the queues of these routers so that network endpoints will be inclined to share router capacity fairly and minimize the overflow of packets trying to enter the queues. We study just how effective some of these queuing policies are when each network endpoint is a self-interested player with no information about the other players’ actions or preferences. By employing the adaptive learning model of evolutionary game theory, we study policies such as Droptail, RED, and the greedy-flow-punishing policy proposed by Gao et al. [10] to find the stochastically stable states: the states of the system that will be reached in the long run.

  13. Congestive heart failure in women in Iraq

    PubMed Central

    Damluji, Salem F.; Al-Saffar, Ghanim; Thamer, Mahmoud A.; Mary, Adil S.

    1964-01-01

    Stimulated by the world-wide interest in cardiovascular diseases, the authors made a study of 1001 consecutive admissions to a female medical ward in Baghdad, Iraq, and found that 146 patients were in congestive failure on admission, and an additional 197 patients were suffering from primary cardiovascular disease without failure. Of the group in failure, 47.9% had rheumatic heart disease; none of these patients had been on chemoprophylaxis. Bilharziasis was associated with a considerable number of cases of hypertension and with a small percentage of cases of cor pulmonale. The authors feel that prevention of rheumatic fever and bilharziasis should constitute the corner-stone of any effective control programme of cardiovascular disease at this stage of medical development in Iraq. PMID:14267742

  14. Treatment of Congestive Heart Failure with Triamterene

    PubMed Central

    Wener, J.; Schucher, R.; Friedman, R.

    1965-01-01

    Triamterene, a newer oral diuretic, was administered to nine hospitalized patients with congestive heart failure for an average of 15 days, and to 22 ambulatory patients for a period of three to 11 months. The daily dosage of triamterene ranged from 50 to 250 mg., but usually 100-200 mg. was administered daily in two divided doses, with or without the addition of 50 mg. of hydrochlorothiazide daily. Triamterene is a safe and effective diuretic at doses of 100-200 mg. daily and no drug tolerance develops with long-term therapy. However, when used alone, it is not as effective as hydrochlorothiazide, but in combination with the latter drug the resultant diuresis is unsurpassed by any other oral diuretic therapy that we have used to date. Triamterene itself does not produce kaliuresis and it blocks thiazide-induced kaliuresis. Serum uric acid levels may rise slightly, but no clinical gout was seen in this study. PMID:14259336

  15. Demand and Congestion in Multiplex Transportation Networks.

    PubMed

    Chodrow, Philip S; Al-Awwad, Zeyad; Jiang, Shan; González, Marta C

    Urban transportation systems are multimodal, sociotechnical systems; however, while their multimodal aspect has received extensive attention in recent literature on multiplex networks, their sociotechnical aspect has been largely neglected. We present the first study of an urban transportation system using multiplex network analysis and validated Origin-Destination travel demand, with Riyadh's planned metro as a case study. We develop methods for analyzing the impact of additional transportation layers on existing dynamics, and show that demand structure plays key quantitative and qualitative roles. There exist fundamental geometrical limits to the metro's impact on traffic dynamics, and the bulk of environmental accrue at metro speeds only slightly faster than those planned. We develop a simple model for informing the use of additional, "feeder" layers to maximize reductions in global congestion. Our techniques are computationally practical, easily extensible to arbitrary transportation layers with complex transfer logic, and implementable in open-source software.

  16. Demand and Congestion in Multiplex Transportation Networks

    PubMed Central

    al-Awwad, Zeyad; Jiang, Shan; González, Marta C.

    2016-01-01

    Urban transportation systems are multimodal, sociotechnical systems; however, while their multimodal aspect has received extensive attention in recent literature on multiplex networks, their sociotechnical aspect has been largely neglected. We present the first study of an urban transportation system using multiplex network analysis and validated Origin-Destination travel demand, with Riyadh’s planned metro as a case study. We develop methods for analyzing the impact of additional transportation layers on existing dynamics, and show that demand structure plays key quantitative and qualitative roles. There exist fundamental geometrical limits to the metro’s impact on traffic dynamics, and the bulk of environmental accrue at metro speeds only slightly faster than those planned. We develop a simple model for informing the use of additional, “feeder” layers to maximize reductions in global congestion. Our techniques are computationally practical, easily extensible to arbitrary transportation layers with complex transfer logic, and implementable in open-source software. PMID:27657738

  17. Local debris congestion in the geosynchronous environment with population augmentation

    NASA Astrophysics Data System (ADS)

    Anderson, Paul V.; Schaub, Hanspeter

    2014-02-01

    Forecasting of localized debris congestion in the geostationary (GEO) regime is performed to investigate how frequently near-miss events occur for each of the longitude slots in the GEO ring. The present-day resident space object (RSO) population at GEO is propagated forward in time to determine current debris congestion conditions, and new probability density functions that describe where GEO satellites are inserted into operational orbits are harnessed to assess longitude-dependent congestion in "business-as-usual" launch traffic, with and without re-orbiting at end-of-life. Congestion forecasting for a 50-year period is presented to illustrate the need for appropriately executed mitigation measures in the GEO ring. Results indicate that localized debris congestion will double within 50 years under current 80% re-orbiting success rates.

  18. Crystal structures of three sterically congested disilanes

    PubMed Central

    Pichaandi, Kothanda Rama

    2017-01-01

    In the three sterically congested silanes, C24H38Si2 (1) (1,1,2,2-tetra­isopropyl-1,2-di­phenyl­disilane), C24H34Br4Si2 (2) [1,1,2,2-tetra­kis­(2-bromo­propan-2-yl)-1,2-di­phenyl­disilane] and C32H38Si2 (3) (1,2-di-tert-butyl-1,1,2,2-tetra­phenyl­disilane), the Si—Si bond length is shortest in (1) and longest in (2), with (3) having an inter­mediate value, which parallels the increasing steric congestion. A comparison of the two isopropyl derivatives, (1 and 2), shows a significant increase in the Si—C(ipso) distance with the introduction of bromine. Also, in the brominated compound 2, attractive inter­molecular Br⋯Br inter­actions exist with Br⋯Br separations ca 0.52 Å shorter than the sum of the van der Waals radii. In compound 2, one of the bromo­isopropyl groups is rotationally disordered in an 0.8812 (9):0.1188 (9) ratio. Compound 3 exhibits ‘whole mol­ecule’ disorder in a 0.9645 (7):0.0355 (7) ratio with the Si—Si bonds in the two components making an angle of ca 66°. PMID:28316829

  19. Agent Reward Shaping for Alleviating Traffic Congestion

    NASA Technical Reports Server (NTRS)

    Tumer, Kagan; Agogino, Adrian

    2006-01-01

    Traffic congestion problems provide a unique environment to study how multi-agent systems promote desired system level behavior. What is particularly interesting in this class of problems is that no individual action is intrinsically "bad" for the system but that combinations of actions among agents lead to undesirable outcomes, As a consequence, agents need to learn how to coordinate their actions with those of other agents, rather than learn a particular set of "good" actions. This problem is ubiquitous in various traffic problems, including selecting departure times for commuters, routes for airlines, and paths for data routers. In this paper we present a multi-agent approach to two traffic problems, where far each driver, an agent selects the most suitable action using reinforcement learning. The agent rewards are based on concepts from collectives and aim to provide the agents with rewards that are both easy to learn and that if learned, lead to good system level behavior. In the first problem, we study how agents learn the best departure times of drivers in a daily commuting environment and how following those departure times alleviates congestion. In the second problem, we study how agents learn to select desirable routes to improve traffic flow and minimize delays for. all drivers.. In both sets of experiments,. agents using collective-based rewards produced near optimal performance (93-96% of optimal) whereas agents using system rewards (63-68%) barely outperformed random action selection (62-64%) and agents using local rewards (48-72%) performed worse than random in some instances.

  20. Agent Reward Shaping for Alleviating Traffic Congestion

    NASA Technical Reports Server (NTRS)

    Tumer, Kagan; Agogino, Adrian

    2006-01-01

    Traffic congestion problems provide a unique environment to study how multi-agent systems promote desired system level behavior. What is particularly interesting in this class of problems is that no individual action is intrinsically "bad" for the system but that combinations of actions among agents lead to undesirable outcomes, As a consequence, agents need to learn how to coordinate their actions with those of other agents, rather than learn a particular set of "good" actions. This problem is ubiquitous in various traffic problems, including selecting departure times for commuters, routes for airlines, and paths for data routers. In this paper we present a multi-agent approach to two traffic problems, where far each driver, an agent selects the most suitable action using reinforcement learning. The agent rewards are based on concepts from collectives and aim to provide the agents with rewards that are both easy to learn and that if learned, lead to good system level behavior. In the first problem, we study how agents learn the best departure times of drivers in a daily commuting environment and how following those departure times alleviates congestion. In the second problem, we study how agents learn to select desirable routes to improve traffic flow and minimize delays for. all drivers.. In both sets of experiments,. agents using collective-based rewards produced near optimal performance (93-96% of optimal) whereas agents using system rewards (63-68%) barely outperformed random action selection (62-64%) and agents using local rewards (48-72%) performed worse than random in some instances.

  1. Blood urea nitrogen to creatinine ratio is associated with congestion and mortality in heart failure patients with renal dysfunction.

    PubMed

    Parrinello, Gaspare; Torres, Daniele; Testani, Jeffrey M; Almasio, Piero Luigi; Bellanca, Michele; Pizzo, Giuseppina; Cuttitta, Francesco; Pinto, Antonio; Butler, Javed; Paterna, Salvatore

    2015-12-01

    Renal dysfunction (RD) and venous congestion are related and common in heart failure (HF). Studies suggest that venous congestion may be the primary driver of RD in HF. In this study, we sought to investigate retrospectively the relationship between common measures of renal function with caval congestion and mortality among outpatients with HF and RD. We reviewed data from 103 HF outpatients (45 males, mean age 74 years, ejection fraction 41.8 ± 11.6 %) with estimated glomerular filtration rate (eGFR) of < 60 ml/min in a single centre. During an ambulatory visit, all patients underwent blood test and ultrasonography of the inferior vena cava (IVC). Caval congestion was defined as IVC with both dilatation and impaired collapsibility. The best values of renal metrics in predicting caval congestion were determined with receiver-operating characteristic analysis. The BUN/Cr ratio is moderately correlated with IVC expiratory maximum diameter (r = 0.31, p < 0.0007). In a multiple logistic regression model, BUN/Cr > 25.5 (adjusted OR 2.98, p 0.015) and eGFR ≤ 45.8 (adjusted OR 5.38, p 0.002) identify patients at risk for caval congestion; a BUN/Cr > 23.7 was the best predictor of impaired collapsibility (adjusted OR 4.41, p 0.001). a BUN/Cr > 25.5 (HR 2.19, 95 % CI 1.21-3.94, p < 0.001) and NYHA class 3 (HR 2.91, 95 % CI 1.60-5.31, p < 0.0005) were independent risk factors associated with all-cause death during a median follow-up of 31 months. In outpatients with HF and RD, a higher BUN/Cr and lower eGFR are reliable renal biomarkers for caval congestion. The BUN/Cr is associated with long-term mortality and may help to stratify HF severity.

  2. Local Debris Congestion in the Geosynchronous Environment with Population Augmentation

    NASA Astrophysics Data System (ADS)

    Anderson, P.; Schaub, H.

    2013-08-01

    Forecasting of localized debris congestion in the geostationary (GEO) ring is performed to investigate how frequently near-miss events occur for every longitude slot at GEO. A parallelized propagation routine is used to propagate the current resident space object (RSO) population at GEO forward in time, and representative augmentation of this population is implemented to simulate congestion in "business-as-usual" launch traffic, with and without mitigation at end-of-life. Congestion forecasting for a 50- year time frame is presented to illustrate the need for both appropriately-executed mitigation and active remediation measures at GEO.

  3. A possible mechanism for the progression of chronic renal disease and congestive heart failure.

    PubMed

    Re, Richard N

    2015-01-01

    Chronic neurologic diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, as well as various forms of chronic renal disease and systolic congestive heart failure, are among the most common progressive degenerative disorders encountered in medicine. Each disease follows a nearly relentless course, albeit at varying rates, driven by progressive cell dysfunction and drop-out. The neurologic diseases are characterized by the progressive spread of disease-causing proteins (prion-like proteins) from cell to cell. Recent evidence indicates that cell autonomous renin angiotensin systems operate in heart and kidney, and it is known that functional intracrine proteins can also spread between cells. This then suggests that certain progressive degenerative cardiovascular disorders such as forms of chronic renal insufficiency and systolic congestive heart failure result from dysfunctional renin angiotensin system intracrine action spreading in kidney or myocardium.

  4. [New antibiotics - standstill or progress].

    PubMed

    Rademacher, J; Welte, T

    2017-04-01

    The development of resistance to antibiotics has been ignored for a long time. But nowadays, increasing resistance is an important topic. For a decade no new antibiotics had been developed and it is not possible to quickly close this gap of new resistance and no new drugs. This work presents six new antibiotics (ceftaroline, ceftobiprole, solithromycin, tedizolid, ceftolozane/tazobactam, ceftazidime/avibactam). In part, only expert opinions are given due to lack of study results.The two 5th generation cephalosporins ceftaroline and ceftobiprole have beside their equivalent efficacy to ceftriaxone (ceftaroline) and cefipim (ceftobiprole) high activity against MRSA. The fluoroketolide solithromycin should help against macrolide-resistant pathogens and has been shown to be noninferior to the fluorochinolones. The oxazolidinone tedizolid is effective against linezolid-resistant MRSA. The two cephalosporins ceftolozane/tazobactam and ceftazidime/avibactam are not only effective against gram-negative pathogens, but they have a very broad spectrum. Due to the efficacy against extended-spectrum β‑lactamases, they can relieve the selection pressure of the carbapenems. We benefit from all new antibiotics which can take the selection pressure from other often used antibiotics. The increasing number of resistant gram-negative pathogens worldwide is alarming. Thus, focusing on the development of new drugs is extremely important.

  5. A Hybrid Differential Invasive Weed Algorithm for Congestion Management

    NASA Astrophysics Data System (ADS)

    Basak, Aniruddha; Pal, Siddharth; Pandi, V. Ravikumar; Panigrahi, B. K.; Das, Swagatam

    This work is dedicated to solve the problem of congestion management in restructured power systems. Nowadays we have open access market which pushes the power system operation to their limits for maximum economic benefits but at the same time making the system more susceptible to congestion. In this regard congestion management is absolutely vital. In this paper we try to remove congestion by generation rescheduling where the cost involved in the rescheduling process is minimized. The proposed algorithm is a hybrid of Invasive Weed Optimization (IWO) and Differential Evolution (DE). The resultant hybrid algorithm was applied on standard IEEE 30 bus system and observed to beat existing algorithms like Simple Bacterial foraging (SBF), Genetic Algorithm (GA), Invasive Weed Optimization (IWO), Differential Evolution (DE) and hybrid algorithms like Hybrid Bacterial Foraging and Differential Evolution (HBFDE) and Adaptive Bacterial Foraging with Nelder Mead (ABFNM).

  6. Congestion Induced by the Structure of Multiplex Networks

    NASA Astrophysics Data System (ADS)

    Solé-Ribalta, Albert; Gómez, Sergio; Arenas, Alex

    2016-03-01

    Multiplex networks are representations of multilayer interconnected complex networks where the nodes are the same at every layer. They turn out to be good abstractions of the intricate connectivity of multimodal transportation networks, among other types of complex systems. One of the most important critical phenomena arising in such networks is the emergence of congestion in transportation flows. Here, we prove analytically that the structure of multiplex networks can induce congestion for flows that otherwise would be decongested if the individual layers were not interconnected. We provide explicit equations for the onset of congestion and approximations that allow us to compute this onset from individual descriptors of the individual layers. The observed cooperative phenomenon is reminiscent of Braess' paradox in which adding extra capacity to a network when the moving entities selfishly choose their route can in some cases reduce overall performance. Similarly, in the multiplex structure, the efficiency in transportation can unbalance the transportation loads resulting in unexpected congestion.

  7. Traffic congestion and the lifetime of networks with moving nodes

    NASA Astrophysics Data System (ADS)

    Yang, Xianxia; Li, Jie; Pu, Cunlai; Yan, Meichen; Sharafat, Rajput Ramiz; Yang, Jian; Gakis, Konstantinos; Pardalos, Panos M.

    2017-01-01

    For many power-limited networks, such as wireless sensor networks and mobile ad hoc networks, maximizing the network lifetime is the first concern in the related designing and maintaining activities. We study the network lifetime from the perspective of network science. In our model, nodes are initially assigned a fixed amount of energy moving in a square area and consume the energy when delivering packets. We obtain four different traffic regimes: no, slow, fast, and absolute congestion regimes, which are basically dependent on the packet generation rate. We derive the network lifetime by considering the specific regime of the traffic flow. We find that traffic congestion inversely affects network lifetime in the sense that high traffic congestion results in short network lifetime. We also discuss the impacts of factors such as communication radius, node moving speed, routing strategy, etc., on network lifetime and traffic congestion.

  8. Efficiency and profit in the NYISO transmission congestion contract market

    SciTech Connect

    Hadsell, Lester; Shawky, Hany A.

    2009-11-15

    Evidence of speculator profit and TCC price less than congestion charges suggests that additional competition in the TCC auction should be encouraged as a way to increase efficiency and lower the price of this ''insurance'' for hedgers. (author)

  9. Autonomous Congestion Control in Delay-Tolerant Networks

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott; Jennings, Esther; Schoolcraft, Joshua

    2006-01-01

    This presentation highlights communication congestion control in delay-tolerant networks (DTNs). Large-scale future space exploration will offer complex communication challenges that may be best addressed by establishing a network infrastructure. However, current internet techniques for congestion control are not well suited for operation of a network over interplanetary distances. An alternative, delay-tolerant technique for congestion control in a delay-tolerant network is presented. A simple DTN was constructed and an experimental congestion control mechanism was applied. The mechanism appeared to be effective and each router was able to make its bundle acceptance decisions autonomously. Future research will examine more complex topologies and alternative bundle acceptance rules that might enhance performance.

  10. Modeling general AIMD congestion control throughput with slow start

    NASA Astrophysics Data System (ADS)

    Yu, Shengsheng; Zha, Hui; Zhou, Jingli

    2005-05-01

    General Additive Increase and Multiplicative Decrease (General AIMD or GAIMD) congestion control generalizes the standard TCP congestion control mechanism. In this paper, we present GAIMD-SS, an enhanced model for predicting the long-term steady-state mean throughput of the GAIMD congestion control, towards more accurate results than previous GAIMD model. We develop a three-state Markov chain for analyzing the behaviors of the GAIMD, and enhance previous works by taking into account the slow start phase and receiver's maximum window limitation. Our experiment and simulation results show that the GAIMD-SS model predicts the sending rate of GAIMD congestion control more accurately than the previous works in a wider range of packet loss rate.

  11. Properties of volume-capacity ratio in congested complex networks

    NASA Astrophysics Data System (ADS)

    Zhu, Zhi-Hong; Zheng, Jian-Feng; Gao, Zi-You; Du, Hao-Ming

    2014-04-01

    The volume-capacity ratio (v/c) is one of the most important indexes to measure the congestion of a traffic network. If v/c is very small, the traffic demand is deficient and/or the transportation supply or capacity is surplus, leading to a waste of capacity; on the contrary, a large value of v/c means that the traffic network is seriously congested. This paper investigates the properties of v/c in complex small-world and scale-free networks by introducing the congestion effects, described by link cost functions. The relationship between v/c and the degree of the node is mainly discussed. Finally, a simple strategy is presented to balance the tradeoff between traffic congestion and a waste of capacity.

  12. Traffic congestion and the lifetime of networks with moving nodes.

    PubMed

    Yang, Xianxia; Li, Jie; Pu, Cunlai; Yan, Meichen; Sharafat, Rajput Ramiz; Yang, Jian; Gakis, Konstantinos; Pardalos, Panos M

    2017-01-01

    For many power-limited networks, such as wireless sensor networks and mobile ad hoc networks, maximizing the network lifetime is the first concern in the related designing and maintaining activities. We study the network lifetime from the perspective of network science. In our model, nodes are initially assigned a fixed amount of energy moving in a square area and consume the energy when delivering packets. We obtain four different traffic regimes: no, slow, fast, and absolute congestion regimes, which are basically dependent on the packet generation rate. We derive the network lifetime by considering the specific regime of the traffic flow. We find that traffic congestion inversely affects network lifetime in the sense that high traffic congestion results in short network lifetime. We also discuss the impacts of factors such as communication radius, node moving speed, routing strategy, etc., on network lifetime and traffic congestion.

  13. Autonomous Congestion Control in Delay-Tolerant Networks

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott; Jennings, Esther; Schoolcraft, Joshua

    2006-01-01

    This presentation highlights communication congestion control in delay-tolerant networks (DTNs). Large-scale future space exploration will offer complex communication challenges that may be best addressed by establishing a network infrastructure. However, current internet techniques for congestion control are not well suited for operation of a network over interplanetary distances. An alternative, delay-tolerant technique for congestion control in a delay-tolerant network is presented. A simple DTN was constructed and an experimental congestion control mechanism was applied. The mechanism appeared to be effective and each router was able to make its bundle acceptance decisions autonomously. Future research will examine more complex topologies and alternative bundle acceptance rules that might enhance performance.

  14. Ameliorating TCP congestion control for improving TCP reliability over wireless networks

    NASA Astrophysics Data System (ADS)

    Xu, Chang-biao; Long, Ke-ping; Xian, Yong-ju

    2004-04-01

    TCP congestion control mechanism, being based on the presupposition that network congestion is the only reason for data loss, is suitable for wired environments rather than for wireless environments with characteristics of higher bit error rate, lower bandwidth, longer delay, frequent mobility and so on, where link corruption can also cause data loss. To avoid unnecessary decrease of packet sending rate resulting in lower throughput and longer delay, some improved TCP congestion mechanisms have been presented. However, one of the disadvantages of these mechanisms is that a great deal of unnecessary packets lost by corruption can be caused while heavy data loss rate by corruption lasts short time. As well known, energy consumption of mobile hosts is one of the most important factors for wireless communication. How to save energy of mobile host has become an important task for wireless communication. One of the methods is to improve reliability to decrease overheads resulting from re-transmitting lost data. Obviously, it is necessary to decrease data sending rate, but how does it do? This paper answers the question, and then presents an improved TCP congestion control mechanism, namely TCP_IR (TCP for Improving Reliability) whose implementations are based on two algorithms. Algorithm I-based TCP_IR is driven by data sending periodic, while algorithm II-based TCP_IR is driven by the event of data lost by corruption. They can be very easily implemented with fewer overheads and can effectively improve TCP reliability with light influence to throughput and delay. The paper"s contribution is to give valuable references to further study TCP in wireless networks.

  15. Magnetic resonance imaging in the evaluation of congestive cardiac failure.

    PubMed

    Rajiah, Prabhakar

    2012-07-01

    Congestive cardiac failure is the end-result of various cardiac disorders, and is a major contributor to morbidity, mortality, and financial burden throughout the world. Due to advances in the knowledge of the disease and scanner technology, magnetic resonance imaging (MRI) is playing an increasingly important role in the evaluation of cardiac failure, including in establishing diagnosis, problem solving, risk stratification, and monitoring of therapy. This review discusses and illustrates the role of MRI in the assessment of congestive cardiac failure.

  16. Reducing congestion on complex networks by dynamic relaxation processes

    NASA Astrophysics Data System (ADS)

    Macri, Pablo A.; Pastore y Piontti, Ana L.; Braunstein, Lidia A.

    2007-12-01

    We study the effects of relaxational dynamics on the congestion pressure in general transport networks. We show that the congestion pressure is reduced in scale-free networks if a relaxation mechanism is utilized, while this is in general not the case for non-scale-free graphs such as random graphs. We also present evidence supporting the idea that the emergence of scale-free networks arise from optimization mechanisms to balance the load of the networks nodes.

  17. Prognostic value of residual pulmonary congestion at discharge assessed by lung ultrasound imaging in heart failure.

    PubMed

    Coiro, Stefano; Rossignol, Patrick; Ambrosio, Giuseppe; Carluccio, Erberto; Alunni, Gianfranco; Murrone, Adriano; Tritto, Isabella; Zannad, Faiez; Girerd, Nicolas

    2015-11-01

    Residual pulmonary congestion at discharge is associated with poor prognosis in heart failure (HF), but its quantification through physical examination is challenging. Ultrasound imaging of lung comets (B-lines) could improve congestion evaluation. The aim of this study was to assess the short-term prognostic value of B-lines after discharge from HF hospitalisation compared with other indices of haemodynamic congestion (BNP, E/e', and inferior vena cava diameter) or clinical status (NYHA class). Sixty consecutive HF inpatients underwent clinical examination, echocardiography, and lung ultrasound at discharge, independently of, and in addition to routine management by the attending physicians. The median B-line count was 8.5 (5-34). Three-month event-free survival for the primary endpoint (all-cause death or HF hospitalisation) was 27 ± 10% in patients with ≥30 B-lines and 88 ± 5% in those with <30 B-lines (P < 0.0001). In a multivariable model, ≥30 B-lines significantly predicted the combined endpoint (hazard ratio 5.66, 95% confidence interval 1.74-18.39, P = 0.04), along with NYHA ≥III and inferior vena cava diameter, while other indirect measures of congestion (BNP and E/e' ≥15) were not retained in the model; furthermore ≥30 B-lines independently also predicted the secondary outcomes (HF hospitalisation and death). Importantly, B-line addition to NYHA class and BNP was associated with improved risk classification (integrated discrimination improvement 15%, P = 0.02; continuous net reclassification improvement 65%, P = 0.03). Residual pulmonary congestion at discharge, as assessed by a B-line count ≥30, is a strong predictor of outcome. Lung ultrasonography may represent a useful tool to identify and monitor congestion and optimize therapy during and/or after hospitalisation for HF, which should be further validated in multicentre studies. © 2015 The Authors European Journal of Heart Failure © 2015 European Society of Cardiology.

  18. A Remote Patient Monitoring System for Congestive Heart Failure

    PubMed Central

    Suh, Myung-kyung; Chen, Chien-An; Woodbridge, Jonathan; Tu, Michael Kai; Kim, Jung In; Nahapetian, Ani; Evangelista, Lorraine S.; Sarrafzadeh, Majid

    2011-01-01

    Congestive heart failure (CHF) is a leading cause of death in the United States affecting approximately 670,000 individuals. Due to the prevalence of CHF related issues, it is prudent to seek out methodologies that would facilitate the prevention, monitoring, and treatment of heart disease on a daily basis. This paper describes WANDA (Weight and Activity with Blood Pressure Monitoring System); a study that leverages sensor technologies and wireless communications to monitor the health related measurements of patients with CHF. The WANDA system is a three-tier architecture consisting of sensors, web servers, and back-end databases. The system was developed in conjunction with the UCLA School of Nursing and the UCLA Wireless Health Institute to enable early detection of key clinical symptoms indicative of CHF-related decompensation. This study shows that CHF patients monitored by WANDA are less likely to have readings fall outside a healthy range. In addition, WANDA provides a useful feedback system for regulating readings of CHF patients. PMID:21611788

  19. [Congestive heart failure in patients with chronic kidney disease].

    PubMed

    Poskurica, Mileta; Petrović, Dejan

    2014-01-01

    Cardiovascular disorders are the most frequent cause of death (46-60%) among patients with advanced chronic renal failure (CRF), and on dialysis treatment. Uremic cardiomyopathy is the basic pathophysiologic substrate, whereas ischemic heart disease (IHD) and anemia are the most important contributing factors. Associated with well-know risk factors and specific disorders for terminal kidney failure and dialysis, the aforementioned factors instigate congestive heart failure (CHF). Suspected CHF is based on the anamnesis, clinical examination and ECG, while it is confirmed and defined more precisely on the basis of echocardiography and radiology examination. Biohumoral data (BNP, NT-proBNP) are not sufficiently reliable because of specific volemic fluctuation and reduced natural clearance. Therapy approach is similar to the one for the general population: ACEI, ARBs, β-blockers, inotropic drugs and diuretics. Hypervolemia and most of the related symptoms can be kept under control effectively by the isolated or ultrafiltation, in conjunction with dialysis, during the standard bicarbonate hemodialysis or hemodiafiltration. In the same respect peritoneal dialysis is efficient for the control of hypervolemia symptoms, mainly during the first years of its application and in case of the lower NYHA class (II°/III°). In general, heart support therapy, surgical interventions of the myocardium and valve replacement are rarely used in patients on dialysis, whereas revascularization procedures are beneficial for associated IHD. In selected cases the application of cardiac resynchronization and/or implantation of a cardioverter defibrillator are advisable.

  20. Congestion, air pollution, and road fatalities in urban areas.

    PubMed

    Shefer, D

    1994-08-01

    The continuous rapid growth in vehicle miles travelled coupled with the rapid increase in traffic congestion on highways of virtually every large urban area, explain a major portion of the observed deterioration of urban air quality. To halt this deterioration and to secure safe and healthy environments and improve the quality of life in our cities, it is useful to initiate and implement programs that treat jointly traffic congestion, air quality, and road safety. Market-based strategies, driven by price mechanisms, have been proposed as the best and most efficient way to decrease traffic congestion and to reduce vehicle emission. Congestion pricing, emission fees, reducing emissions of high-polluting vehicles, and introducing more efficient vehicle and/or fuel technologies are not mutually exclusive strategies and therefore they can be employed jointly within an overall strategy. In view of the conflicting objectives that may exist between improving urban air quality and reducing road fatalities and traffic congestion, it is of great importance to investigate thoroughly these functional relationships. The results of such studies will help decision makers identify the "socially optimal level of congestion" that will yield the highest net social benefit.

  1. A theory of traffic congestion at moving bottlenecks

    NASA Astrophysics Data System (ADS)

    Kerner, Boris S.; Klenov, Sergey L.

    2010-10-01

    The physics of traffic congestion occurring at a moving bottleneck on a multi-lane road is revealed based on the numerical analyses of vehicular traffic with a discrete stochastic traffic flow model in the framework of three-phase traffic theory. We find that there is a critical speed of a moving bottleneck at which traffic breakdown, i.e. a first-order phase transition from free flow to synchronized flow, occurs spontaneously at the moving bottleneck, if the flow rate upstream of the bottleneck is great enough. The greater the flow rate, the higher the critical speed of the moving bottleneck. A diagram of congested traffic patterns at the moving bottleneck is found, which shows regions in the flow-rate-moving-bottleneck-speed plane in which congested patterns emerge spontaneously or can be induced through large enough disturbances in an initial free flow. A comparison of features of traffic breakdown and resulting congested patterns at the moving bottleneck with known ones at an on-ramp (and other motionless) bottleneck is made. Nonlinear features of complex interactions and transformations of congested traffic patterns occurring at on- and off-ramp bottlenecks due to the existence of the moving bottleneck are found. The physics of the phenomenon of traffic congestion due to 'elephant racing' on a multi-lane road is revealed.

  2. Local empathy provides global minimization of congestion in communication networks

    NASA Astrophysics Data System (ADS)

    Meloni, Sandro; Gómez-Gardeñes, Jesús

    2010-11-01

    We present a mechanism to avoid congestion in complex networks based on a local knowledge of traffic conditions and the ability of routers to self-coordinate their dynamical behavior. In particular, routers make use of local information about traffic conditions to either reject or accept information packets from their neighbors. We show that when nodes are only aware of their own congestion state they self-organize into a hierarchical configuration that delays remarkably the onset of congestion although leading to a sharp first-order-like congestion transition. We also consider the case when nodes are aware of the congestion state of their neighbors. In this case, we show that empathy between nodes is strongly beneficial to the overall performance of the system and it is possible to achieve larger values for the critical load together with a smooth, second-order-like, transition. Finally, we show how local empathy minimize the impact of congestion as much as global minimization. Therefore, here we present an outstanding example of how local dynamical rules can optimize the system’s functioning up to the levels reached using global knowledge.

  3. Optimal structure of complex networks for minimizing traffic congestion.

    PubMed

    Zhao, Liang; Cupertino, Thiago Henrique; Park, Kwangho; Lai, Ying-Cheng; Jin, Xiaogang

    2007-12-01

    To design complex networks to minimize traffic congestion, it is necessary to understand how traffic flow depends on network structure. We study data packet flow on complex networks, where the packet delivery capacity of each node is not fixed. The optimal configuration of capacities to minimize traffic congestion is derived and the critical packet generating rate is determined, below which the network is at a free flow state but above which congestion occurs. Our analysis reveals a direct relation between network topology and traffic flow. Optimal network structure, free of traffic congestion, should have two features: uniform distribution of load over all nodes and small network diameter. This finding is confirmed by numerical simulations. Our analysis also makes it possible to theoretically compare the congestion conditions for different types of complex networks. In particular, we find that network with low critical generating rate is more susceptible to congestion. The comparison has been made on the following complex-network topologies: random, scale-free, and regular.

  4. Local empathy provides global minimization of congestion in communication networks.

    PubMed

    Meloni, Sandro; Gómez-Gardeñes, Jesús

    2010-11-01

    We present a mechanism to avoid congestion in complex networks based on a local knowledge of traffic conditions and the ability of routers to self-coordinate their dynamical behavior. In particular, routers make use of local information about traffic conditions to either reject or accept information packets from their neighbors. We show that when nodes are only aware of their own congestion state they self-organize into a hierarchical configuration that delays remarkably the onset of congestion although leading to a sharp first-order-like congestion transition. We also consider the case when nodes are aware of the congestion state of their neighbors. In this case, we show that empathy between nodes is strongly beneficial to the overall performance of the system and it is possible to achieve larger values for the critical load together with a smooth, second-order-like, transition. Finally, we show how local empathy minimize the impact of congestion as much as global minimization. Therefore, here we present an outstanding example of how local dynamical rules can optimize the system's functioning up to the levels reached using global knowledge.

  5. Abrupt transition to complete congestion on complex networks and control.

    PubMed

    Wang, Wen-Xu; Wu, Zhi-Xi; Jiang, Rui; Chen, Guanrong; Lai, Ying-Cheng

    2009-09-01

    Previous works on traffic-flow dynamics on complex networks have mostly focused on continuous phase transition from a free-flow state to a locally congested state as a parameter, such as the packet-generating rate, is increased through a critical value. Above the transition point congestion occurs on a small subset of nodes. Utilizing a conventional traffic-flow model based on the packet birth-death process and more importantly, taking into account the fact that in realistic networks nodes have only finite buffers, we find an abrupt transition from free flow to complete congestion. Slightly below the transition point, the network can support the maximum amount of traffic for some optimal value of the routing parameter. We develop a mean-field theory to explain the surprising transition phenomenon and provide numerical support. Furthermore, we propose a control strategy based on the idea of random packet dropping to prevent/break complete congestion. Our finding provides insights into realistic communication networks where complete congestion can occur directly from a free-flow state without any apparent precursor, and our control strategy can be effective to restore traffic flow once complete congestion has occurred.

  6. Congestion Transition in Air Traffic Networks

    PubMed Central

    Monechi, Bernardo; Servedio, Vito D. P.; Loreto, Vittorio

    2015-01-01

    Air Transportation represents a very interesting example of a complex techno-social system whose importance has considerably grown in time and whose management requires a careful understanding of the subtle interplay between technological infrastructure and human behavior. Despite the competition with other transportation systems, a growth of air traffic is still foreseen in Europe for the next years. The increase of traffic load could bring the current Air Traffic Network above its capacity limits so that safety standards and performances might not be guaranteed anymore. Lacking the possibility of a direct investigation of this scenario, we resort to computer simulations in order to quantify the disruptive potential of an increase in traffic load. To this end we model the Air Transportation system as a complex dynamical network of flights controlled by humans who have to solve potentially dangerous conflicts by redirecting aircraft trajectories. The model is driven and validated through historical data of flight schedules in a European national airspace. While correctly reproducing actual statistics of the Air Transportation system, e.g., the distribution of delays, the model allows for theoretical predictions. Upon an increase of the traffic load injected in the system, the model predicts a transition from a phase in which all conflicts can be successfully resolved, to a phase in which many conflicts cannot be resolved anymore. We highlight how the current flight density of the Air Transportation system is well below the transition, provided that controllers make use of a special re-routing procedure. While the congestion transition displays a universal scaling behavior, its threshold depends on the conflict solving strategy adopted. Finally, the generality of the modeling scheme introduced makes it a flexible general tool to simulate and control Air Transportation systems in realistic and synthetic scenarios. PMID:25993476

  7. Congestion transition in air traffic networks.

    PubMed

    Monechi, Bernardo; Servedio, Vito D P; Loreto, Vittorio

    2015-01-01

    Air Transportation represents a very interesting example of a complex techno-social system whose importance has considerably grown in time and whose management requires a careful understanding of the subtle interplay between technological infrastructure and human behavior. Despite the competition with other transportation systems, a growth of air traffic is still foreseen in Europe for the next years. The increase of traffic load could bring the current Air Traffic Network above its capacity limits so that safety standards and performances might not be guaranteed anymore. Lacking the possibility of a direct investigation of this scenario, we resort to computer simulations in order to quantify the disruptive potential of an increase in traffic load. To this end we model the Air Transportation system as a complex dynamical network of flights controlled by humans who have to solve potentially dangerous conflicts by redirecting aircraft trajectories. The model is driven and validated through historical data of flight schedules in a European national airspace. While correctly reproducing actual statistics of the Air Transportation system, e.g., the distribution of delays, the model allows for theoretical predictions. Upon an increase of the traffic load injected in the system, the model predicts a transition from a phase in which all conflicts can be successfully resolved, to a phase in which many conflicts cannot be resolved anymore. We highlight how the current flight density of the Air Transportation system is well below the transition, provided that controllers make use of a special re-routing procedure. While the congestion transition displays a universal scaling behavior, its threshold depends on the conflict solving strategy adopted. Finally, the generality of the modeling scheme introduced makes it a flexible general tool to simulate and control Air Transportation systems in realistic and synthetic scenarios.

  8. [Intraoperative fluid therapy in infants with congestive heart failure due to intracranial pial arteriovenous fistula].

    PubMed

    Arroyo-Fernández, F J; Calderón-Seoane, E; Rodríguez-Peña, F; Torres-Morera, L M

    2016-05-01

    Pial arteriovenous fistula is a rare intracranial congenital malformation (0.1-1: 100,000). It has a high blood flow between one or more pial arteries and drains into the venous circulation. It is usually diagnosed during the childhood by triggering an intracranial hypertension and/or congestive heart failure due to left-right systemic shunt. It is a rare malformation with a complex pathophysiology. The perioperative anaesthetic management is not well established. We present a 6-month-old infant diagnosed with pial arteriovenous fistula with hypertension and congestive heart failure due to left-right shunt. He required a craniotomy and clipping of vascular malformation. Anaesthetic considerations in patients with this condition are a great challenge. It must be performed by multidisciplinary teams with experience in paediatrics. The maintenance of blood volume during the intraoperative course is very important. Excessive fluid therapy can precipitate a congestive heart failure or intracranial hypertension, and a lower fluid therapy may cause a tissue hypoxia due to the bleeding. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. A Novel Congestion Avoidance Technique for Simultaneous Real-Time Medical Data Transmission.

    PubMed

    Yaakob, Naimah; Khalil, Ibrahim

    2016-03-01

    The use of wireless body sensor networks (WBSN) in medical services aims at providing continuous monitoring of patients' physiological data. However, the scarce resources in WBSN nodes limit their capabilities to cope with massive traffic during multiple, simultaneous data transmissions. This will create a high tendency for congestion, causing severe performance degradation. Congestion may lead to high number of packet loss and unbounded delay which are critical and may lead to wrong diagnosis. This paper, therefore, aims at improving this limitation using a novel congestion avoidance technique to avoid losing real-time and life-critical medical data (e.g., electrocardiogram and electroencephalography) which are vital for diagnosis. The main idea is to integrate the existing rate control scheme of relaxation theory (RT) with a method known as max-min fairness (MMF) to achieve better performance. The MMF can be accomplished using a progressive filling algorithm, which cuts-down excessive sending rates that may overwhelme the limited buffer in WBSN. This paper builds upon our prior study, which provides a preliminary analysis of RT technique in single node. Our current technique integrates the MMF phase to enhance RT performance when the transmission rates exceed certain threshold. Performance evaluation on RT-MMF technique shows remarkable performance improvements, while maintaining the desired quality of service.

  10. Role of brain serotonin dysfunction in the pathophysiology of congestive heart failure.

    PubMed

    Li, Lei; Morimoto, Sachio; Take, Sachiko; Zhan, Dong-Yun; Du, Cheng-Kun; Wang, Yuan-Yuan; Fan, Xue-Li; Yoshihara, Tatsuya; Takahashi-Yanaga, Fumi; Katafuchi, Toshihiko; Sasaguri, Toshiyuki

    2012-12-01

    Inherited or non-inherited dilated cardiomyopathy (DCM) patients develop varied disease phenotypes leading to death after developing congestive heart failure (HF) or sudden death with mild or no overt HF symptoms, suggesting that environmental and/or genetic factors may modify the disease phenotype of DCM. In this study, we sought to explore unknown genetic factors affecting the disease phenotype of monogenic inherited human DCM. Knock-in mice bearing a sarcomeric protein mutation that causes DCM were created on different genetic backgrounds; BALB/c and C57Bl/6. DCM mice on the BALB/c background showed cardiac enlargement and systolic dysfunction and developed congestive HF before died. In contrast, DCM mice on the C57Bl/6 background developed no overt HF symptoms and died suddenly, although they showed considerable cardiac enlargement and systolic dysfunction. BALB/c mice have brain serotonin dysfunction due to a single nucleotide polymorphism (SNP) in tryptophan hydroxylase 2 (TPH2). Brain serotonin dysfunction plays a critical role in depression and anxiety and BALB/c mice exhibit depression- and anxiety-related behaviors. Since depression is common and associated with poor prognosis in HF patients, we examined therapeutic effects of anti-depression drug paroxetine and anti-anxiety drug buspirone that could improve the brain serotonin function in mice. Both drugs reduced cardiac enlargement and improved systolic dysfunction and symptoms of severe congestive HF in DCM mice on the BALB/c background. These results strongly suggest that genetic backgrounds involving brain serotonin dysfunction, such as TPH2 gene SNP, may play an important role in the development of congestive HF in DCM.

  11. Effects of desipramine on norepinephrine clearance in congestive heart failure

    SciTech Connect

    Clemson, B.; Baily, R.G.; Davis, D.; Zelis, R. )

    1990-08-01

    Elevated plasma norepinephrine (NE) in congestive heart failure (CHF) is caused by increased NE spillover and decreased NE clearance. To evaluate the effects of neuronal uptake blockade on NE clearance, we studied NE kinetics during steady-state infusions of (3H)NE, before and after oral desipramine (DMI, 50 mg) in 11 patients with CHF and 8 normal volunteers. Baseline plasma NE was greater in the CHF group (637 +/- 56 vs. 271 +/- 32 pg/ml; P less than 0.001), NE clearance was lower in CHF (1.31 +/- 0.21 vs. 1.94 +/- 0.17 l.min-1.m-2; P = 0.026), and NE spillover was greater in CHF (4.71 +/- 0.78 vs. 3.04 +/- 0.35 nmol.min-1.m-2, P = 0.054). After DMI, plasma NE rose significantly in CHF (778 +/- 67; P = 0.008), and NE clearance decreased further in CHF (0.97 +/- 0.16; P = 0.024), but neither changed in normal subjects. NE spillover did not change in either group. There appears to be an enhanced effect of DMI on NE clearance in CHF patients. Two general mechanisms may be responsible for this finding, an increased concentration of drug, possibly caused by a decreased volume of distribution, and an increased sensitivity of neuronal amine pumps to DMI. Both mechanisms may reflect a more general abnormality of clearance of drugs and hormones related to abnormalities of tissue perfusion in CHF.

  12. Congestive Heart Failure During Osimertinib Treatment for Epidermal Growth Factor Receptor (EGFR)-mutant Non-small Cell Lung Cancer (NSCLC).

    PubMed

    Watanabe, Hiromi; Ichihara, Eiki; Kano, Hirohisa; Ninomiya, Kiichiro; Tanimoto, Mitsune; Kiura, Katsuyuki

    2017-08-15

    We herein report a case of congestive heart failure which developed during osimertinib treatment. A 78-year-old woman presented with mild exertional dyspnea three weeks after starting osimertinib for the treatment of epidermal growth factor receptor (EGFR) T790M-positive non-small cell lung cancer. She was diagnosed with congestive heart failure caused by the osimertinib. In contrast to trastuzumab, a human epidermal growth factor receptor 2 (HER2) monoclonal antibody that often causes cardiac dysfunction, the causal relationship between osimertinib and cardiotoxicity has so far received little attention and thus remains unclear. However, it inhibits HER2 in addition to mutant EGFR, thereby potentially causing cardiotoxicity.

  13. Water and Sodium in Heart Failure: A Spotlight on Congestion

    PubMed Central

    Greene, Stephen J.; Torres, Daniele; Alderman, Michael; Bonventre, Joseph Vincent; Di Pasquale, Pietro; Gargani, Luna; Nohria, Anju; Fonarow, Gregg C.; Vaduganathan, Muthiah; Butler, Javed; Paterna, Salvatore; Stevenson, Lynne Warner; Gheorghiade, Mihai

    2015-01-01

    Despite all available therapies, the rates of hospitalization and death from heart failure (HF) remain unacceptably high. The most common reasons for hospital admission are symptoms related to congestion. During hospitalization, most patients respond well to standard therapy and are discharged with significantly improved symptoms. Post-discharge, many patients receive diligent and frequent follow-up. However, rehospitalization rates remain high. One potential explanation is a persistent failure by clinicians to adequately manage congestion in the outpatient setting. The failure to successfully manage these patients post-discharge may represent an unmet need to improve the way congestion is both recognized and treated. A primary aim of future HF management may be to improve clinical surveillance to prevent and manage chronic fluid overload while simultaneously maximizing the use of evidence-based therapies with proven long-term benefit. Improvement in cardiac function is the ultimate goal and maintenance of a “dry” clinical profile is important to prevent hospital admission and improve prognosis. This paper focuses on methods for monitoring congestion, and strategies for water and sodium management in the context of the complex interplay between the cardiac and renal systems. A rationale for improving recognition and treatment of congestion is also proposed. PMID:24942806

  14. Water and sodium in heart failure: a spotlight on congestion.

    PubMed

    Parrinello, Gaspare; Greene, Stephen J; Torres, Daniele; Alderman, Michael; Bonventre, Joseph Vincent; Di Pasquale, Pietro; Gargani, Luna; Nohria, Anju; Fonarow, Gregg C; Vaduganathan, Muthiah; Butler, Javed; Paterna, Salvatore; Stevenson, Lynne Warner; Gheorghiade, Mihai

    2015-01-01

    Despite all available therapies, the rates of hospitalization and death from heart failure (HF) remain unacceptably high. The most common reasons for hospital admission are symptoms related to congestion. During hospitalization, most patients respond well to standard therapy and are discharged with significantly improved symptoms. Post-discharge, many patients receive diligent and frequent follow-up. However, rehospitalization rates remain high. One potential explanation is a persistent failure by clinicians to adequately manage congestion in the outpatient setting. The failure to successfully manage these patients post-discharge may represent an unmet need to improve the way congestion is both recognized and treated. A primary aim of future HF management may be to improve clinical surveillance to prevent and manage chronic fluid overload while simultaneously maximizing the use of evidence-based therapies with proven long-term benefit. Improvement in cardiac function is the ultimate goal and maintenance of a "dry" clinical profile is important to prevent hospital admission and improve prognosis. This paper focuses on methods for monitoring congestion, and strategies for water and sodium management in the context of the complex interplay between the cardiac and renal systems. A rationale for improving recognition and treatment of congestion is also proposed.

  15. CONGESTIVE HEART FAILURE ASSOCIATED WITH PREGNANCY IN OKAPI (OKAPIA JOHNSTONI).

    PubMed

    Warren, Joshua D; Aitken-Palmer, Copper; Weldon, Alan D; Flanagan, Joseph P; Howard, Lauren L; Garner, Michael M; Citino, Scott B

    2017-03-01

    Acute signs associated with cardiovascular disease occurred in three pregnant okapi ( Okapia johnstoni ) during early to midgestation and progressed to congestive heart failure. Congestive heart failure was diagnosed antemortem using echocardiography and plasma cardiac troponin levels. Clinical signs included decreased activity, hyporexia, tachypnea, dyspnea, flared nostrils, and productive coughing with copious amounts of foamy nasal discharge. Parenteral and oral treatment with furosemide, enalapril, and spironolactone controlled clinical signs in the three okapi allowing each to carry out one pregnancy to term. Two okapi carried the first pregnancy to term after showing signs, while one okapi aborted the first calf and gave birth to a healthy calf in a subsequent pregnancy. Subsequent pregnancy in one okapi ended with abortion and associated dystocia and endometritis. Following parturition, clinical signs associated with heart failure resolved in all three individuals; serial echocardiography in two individuals showed improvement in fractional shortening and left atrial size and all three okapi showed markedly decreased pleural effusion and resolution of pulmonary edema. However, subsequent pregnancies in all three okapi induced respiratory distress and recurrence of congestive heart failure; one okapi died from congestive heart failure associated with subsequent pregnancy. This case series describes the clinical presentation and pathologic findings of congestive heart failure during pregnancy in adult okapi.

  16. Reliability and Congestion Effects on Embedded Cost of Transmission Services

    NASA Astrophysics Data System (ADS)

    Shooshtari, Alireza Tavakoli; Joorabian, Mahmood; Milani, Armin Ebrahimi

    2011-06-01

    The aim of this paper is to make a novel method for calculating the investment cost of Transmission services. It should be noted that some considerations such as used capacity, profits of reliability and profits of decreasing congestion-the money allocated to transmission services- are also taken into account. The proposed method is tested on an 8 bus test system. All simulations are done in MATLAB environment, and MATPOWER is used for Power Flow Analysis. In order to verify the proposed method, the optimal results are compared with the pervious techniques. Therefore, the proposed technique in the paper has important effects on investment on transmission network by improving the profits of reliability and decreasing congestion. Furthermore, simulations show that increasing maximum acceptable level of current will decrease the profit of decreasing congestion.

  17. A Circuit Simulation Technique for Congested Network Traffic Assignment Problem

    NASA Astrophysics Data System (ADS)

    Cho, Hsun-Jung; Huang, Heng

    2007-12-01

    The relation between electrical circuit and traffic network has been proposed by Sasaki and Inouye, but they proposed link cost function is a linear function which cannot present the congestion situation. Cho and Huang extended the link cost function to a nonlinear function which can explain the congested network. In this paper, we proposed a foremost and novel approach to solve the traffic assignment problem (TAP) by simulating the electrical circuit network which consists of nonlinear link cost function models. Comparing with the solutions of Frank-Wolfe algorithm, the simulation results are nearly identical. Thus, the simulation of a network circuit model can be applied to solve network traffic assignment problems. Finally, two examples are proposed, and the results confirmed that electrical circuit simulation is workable in solving congested network traffic assignment problems.

  18. Traffic Congestion Detection System through Connected Vehicles and Big Data.

    PubMed

    Cárdenas-Benítez, Néstor; Aquino-Santos, Raúl; Magaña-Espinoza, Pedro; Aguilar-Velazco, José; Edwards-Block, Arthur; Medina Cass, Aldo

    2016-04-28

    This article discusses the simulation and evaluation of a traffic congestion detection system which combines inter-vehicular communications, fixed roadside infrastructure and infrastructure-to-infrastructure connectivity and big data. The system discussed in this article permits drivers to identify traffic congestion and change their routes accordingly, thus reducing the total emissions of CO₂ and decreasing travel time. This system monitors, processes and stores large amounts of data, which can detect traffic congestion in a precise way by means of a series of algorithms that reduces localized vehicular emission by rerouting vehicles. To simulate and evaluate the proposed system, a big data cluster was developed based on Cassandra, which was used in tandem with the OMNeT++ discreet event network simulator, coupled with the SUMO (Simulation of Urban MObility) traffic simulator and the Veins vehicular network framework. The results validate the efficiency of the traffic detection system and its positive impact in detecting, reporting and rerouting traffic when traffic events occur.

  19. Self-adapting network topologies in congested scenarios.

    PubMed

    Cholvi, Vicent; Laderas, Víctor; López, Luis; Fernández, Antonio

    2005-03-01

    Most studies in complex networks assume that once a link is created between two nodes it is never deleted. However, there is a recent interest towards systems where links can be rapidly rewired. An important issue in that type of networks is to discover the topology that, given a search algorithm, optimizes the search process. In this paper, we present a system model that, depending on the current network congestion, makes nodes to establish link connections so that the resulting topologies tend to a starlike topology when congestion is small and to randomlike topologies when congestion becomes relevant. Those topologies have been shown to be optimal in the above-mentioned conditions. Such a model can be easily implemented in practice and therefore, may be relevant in areas as the topology management of peer-to-peer networks.

  20. Involvement of systemic venous congestion in heart failure.

    PubMed

    Rubio Gracia, J; Sánchez Marteles, M; Pérez Calvo, J I

    2017-04-01

    Systemic venous congestion has gained significant importance in the interpretation of the pathophysiology of acute heart failure, especially in the development of renal function impairment during exacerbations. In this study, we review the concept, clinical characterisation and identification of venous congestion. We update current knowledge on its importance in the pathophysiology of acute heart failure and its involvement in the prognosis. We pay special attention to the relationship between abdominal congestion, the pulmonary interstitium as filtering membrane, inflammatory phenomena and renal function impairment in acute heart failure. Lastly, we review decongestion as a new therapeutic objective and the measures available for its assessment. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  1. Pulmonary Vascular Congestion: A Mechanism for Distal Lung Unit Dysfunction in Obesity

    PubMed Central

    Oppenheimer, Beno W.; Berger, Kenneth I.; Ali, Saleem; Segal, Leopoldo N.; Donnino, Robert; Katz, Stuart; Parikh, Manish; Goldring, Roberta M.

    2016-01-01

    Rationale Obesity is characterized by increased systemic and pulmonary blood volumes (pulmonary vascular congestion). Concomitant abnormal alveolar membrane diffusion suggests subclinical interstitial edema. In this setting, functional abnormalities should encompass the entire distal lung including the airways. Objectives We hypothesize that in obesity: 1) pulmonary vascular congestion will affect the distal lung unit with concordant alveolar membrane and distal airway abnormalities; and 2) the degree of pulmonary congestion and membrane dysfunction will relate to the cardiac response. Methods 54 non-smoking obese subjects underwent spirometry, impulse oscillometry (IOS), diffusion capacity (DLCO) with partition into membrane diffusion (DM) and capillary blood volume (VC), and cardiac MRI (n = 24). Alveolar-capillary membrane efficiency was assessed by calculation of DM/VC. Measurements and Main Results Mean age was 45±12 years; mean BMI was 44.8±7 kg/m2. Vital capacity was 88±13% predicted with reduction in functional residual capacity (58±12% predicted). Despite normal DLCO (98±18% predicted), VC was elevated (135±31% predicted) while DM averaged 94±22% predicted. DM/VC varied from 0.4 to 1.4 with high values reflecting recruitment of alveolar membrane and low values indicating alveolar membrane dysfunction. The most abnormal IOS (R5 and X5) occurred in subjects with lowest DM/VC (r2 = 0.31, p<0.001; r2 = 0.34, p<0.001). Cardiac output and index (cardiac output / body surface area) were directly related to DM/VC (r2 = 0.41, p<0.001; r2 = 0.19, p = 0.03). Subjects with lower DM/VC demonstrated a cardiac output that remained in the normal range despite presence of obesity. Conclusions Global dysfunction of the distal lung (alveolar membrane and distal airway) is associated with pulmonary vascular congestion and failure to achieve the high output state of obesity. Pulmonary vascular congestion and consequent fluid transudation and/or alterations in the

  2. [Erythropoiesis-stimulating agents in congestive heart failure patients].

    PubMed

    Robles Perez-Monteoliva, Nicolás Roberto; Macías Núñez, Juan Francisco; Herrera Pérez de Villar, Julio

    2014-03-04

    Congestive heart failure is a disease of high incidence and prevalence in the elderly. Anemia is associated with an increased mortality in these patients. This article reviews the cumulated evidence about the use of erythropoiesis-stimulating agents in congestive heart failure patients. Although some improvement in quality of life has been shown, it has not been found any decrement on mortality and, as a result, together with the high drug cost, it is not recommended the use of this kind of drugs in heart failure patients.

  3. Ultrafiltration in the management of refractory congestive heart failure.

    PubMed Central

    Simpson, I A; Rae, A P; Simpson, K; Gribben, J; Boulton Jones, J M; Allison, M E; Hutton, I

    1986-01-01

    Ultrafiltration was performed in nine patients with congestive cardiac failure that was refractory to conventional medical treatment. A mean of 12 X 7 litres of fluid was removed, and there was a sustained symptomatic improvement in all patients. Weight loss continued after ultrafiltration and a sustained increase in serum sodium concentration was also noted. A transient fall in right atrial pressure was seen only at four hours after ultrafiltration. No adverse haemodynamic effects were seen four and eighteen hours after fluid removal. Intracardiac dimensions measured by echocardiography remained unchanged. Ultrafiltration can be used to relieve symptoms in patients with refractory congestive heart failure and gross oedema. PMID:3964500

  4. Congestive heart failure and other medical facts about ferrets.

    PubMed

    Williams, Lavonn A

    2009-01-01

    Congestive heart failure, the most common form of heart disease in aged ferrets, is only one of the diseases to which ferrets are susceptible. Congestive heart failure is an insidious, progressive disease for which there is no cure. Once the diagnosis is made and the proper medication is determined, the ferret must remain on the medication. The case report included with this article, which was submitted by a pet owner, and the accompanying formula is an example of how a compounding pharmacist can work with the veterinarian to aid in the treatment of a small veterinary patient by preparing specific medications.

  5. Traffic congestion classification using motion vector statistical features

    NASA Astrophysics Data System (ADS)

    Riaz, Amina; Khan, Shoab A.

    2013-12-01

    Due to the rapid increase in population, one of the major problems faced by the urban areas is traffic congestion. In this paper we propose a method for classifying highway traffic congestion using motion vector statistical properties. Motion vectors are estimated using pyramidal Kanada-Lucas-Tomasi (KLT) tracker algorithm. Then motion vector features are extracted and are used to classify the traffic patterns into three categories: light, medium and heavy. Classification using neural network, on publicly available dataset, shows an accuracy of 95.28%, with robustness to environmental conditions such as variable luminance. Our system provides a more accurate solution to the problem as compared to the systems previously proposed.

  6. Acute Spinal Subdural Hematoma after Vertebroplasty: A Case Report Emphasizing the Possible Etiologic Role of Venous Congestion.

    PubMed

    Mattei, Tobias A; Rehman, Azeem A; Dinh, Dzung H

    2015-10-01

    Study Design Case report and literature review. Objective Spinal subdural hematomas are rare events that often progress with severe neurologic deficits. Although there have been several case reports in the literature of spontaneous spinal subdural hematomas in the setting of anticoagulation, antiplatelet therapy, or coagulation disorders, the exact pathophysiology of such phenomena remains obscure. Methods We present the first report of a subdural hematoma after a percutaneous vertebroplasty and provide a comprehensive review on the anatomy of venous drainage of the vertebral bodies with emphasis on the possible effects of venous congestion caused by cement obstruction. Results Because the subdural hematoma occurred in the absence of major cement extravasation to the spinal canal and two levels above the site of the vertebroplasty, we discuss the possible role of venous congestion as the main etiologic factor leading to rupture of the fragile, valveless radiculomedullary veins into the subdural space. Conclusions The reported case supports a possible new pathophysiological scheme for the development of spinal subdural hematoma in which venous congestion plays a pivotal etiologic role. The reported findings suggests that future anatomical and histologic studies investigating the response of the radiculomedullary veins to congestive venous hypertension may shed new light into the pathophysiology of spinal subdural hematomas.

  7. Increasing Intelligence in Inter-Vehicle Communications to Reduce Traffic Congestions: Experiments in Urban and Highway Environments

    PubMed Central

    Filho, Geraldo P. R.; Guidoni, Daniel L.; Pessin, Gustavo; Villas, Leandro A.; Ueyama, Jó

    2016-01-01

    Intelligent Transportation Systems (ITS) rely on Inter-Vehicle Communication (IVC) to streamline the operation of vehicles by managing vehicle traffic, assisting drivers with safety and sharing information, as well as providing appropriate services for passengers. Traffic congestion is an urban mobility problem, which causes stress to drivers and economic losses. In this context, this work proposes a solution for the detection, dissemination and control of congested roads based on inter-vehicle communication, called INCIDEnT. The main goal of the proposed solution is to reduce the average trip time, CO emissions and fuel consumption by allowing motorists to avoid congested roads. The simulation results show that our proposed solution leads to short delays and a low overhead. Moreover, it is efficient with regard to the coverage of the event and the distance to which the information can be propagated. The findings of the investigation show that the proposed solution leads to (i) high hit rate in the classification of the level of congestion, (ii) a reduction in average trip time, (iii) a reduction in fuel consumption, and (iv) reduced CO emissions PMID:27526048

  8. Rate-based congestion control in networks with smart links, revision. B.S. Thesis - May 1988

    NASA Technical Reports Server (NTRS)

    Heybey, Andrew Tyrrell

    1990-01-01

    The author uses a network simulator to explore rate-based congestion control in networks with smart links that can feed back information to tell senders to adjust their transmission rates. This method differs in a very important way from congestion control in which a congested network component just drops packets - the most commonly used method. It is clearly advantageous for the links in the network to communicate with the end users about the network capacity, rather than the users unilaterally picking a transmission rate. The components in the middle of the network, not the end users, have information about the capacity and traffic in the network. The author experiments with three different algorithms for calculating the control rate to feed back to the users. All of the algorithms exhibit problems in the form of large queues when simulated with a configuration modeling the dynamics of a packet-voice system. However, the problems are not with the algorithms themselves, but with the fact that feedback takes time. If the network steady-state utilization is low enough that it can absorb transients in the traffic through it, then the large queues disappear. If the users are modified to start sending slowly, to allow the network to adapt to a new flow without causing congestion, a greater portion of the network's bandwidth can be used.

  9. Acute Spinal Subdural Hematoma after Vertebroplasty: A Case Report Emphasizing the Possible Etiologic Role of Venous Congestion

    PubMed Central

    Mattei, Tobias A.; Rehman, Azeem A.; Dinh, Dzung H.

    2015-01-01

    Study Design Case report and literature review. Objective Spinal subdural hematomas are rare events that often progress with severe neurologic deficits. Although there have been several case reports in the literature of spontaneous spinal subdural hematomas in the setting of anticoagulation, antiplatelet therapy, or coagulation disorders, the exact pathophysiology of such phenomena remains obscure. Methods We present the first report of a subdural hematoma after a percutaneous vertebroplasty and provide a comprehensive review on the anatomy of venous drainage of the vertebral bodies with emphasis on the possible effects of venous congestion caused by cement obstruction. Results Because the subdural hematoma occurred in the absence of major cement extravasation to the spinal canal and two levels above the site of the vertebroplasty, we discuss the possible role of venous congestion as the main etiologic factor leading to rupture of the fragile, valveless radiculomedullary veins into the subdural space. Conclusions The reported case supports a possible new pathophysiological scheme for the development of spinal subdural hematoma in which venous congestion plays a pivotal etiologic role. The reported findings suggests that future anatomical and histologic studies investigating the response of the radiculomedullary veins to congestive venous hypertension may shed new light into the pathophysiology of spinal subdural hematomas. PMID:26430602

  10. Rate-based congestion control in networks with smart links, revision. B.S. Thesis - May 1988

    NASA Technical Reports Server (NTRS)

    Heybey, Andrew Tyrrell

    1990-01-01

    The author uses a network simulator to explore rate-based congestion control in networks with smart links that can feed back information to tell senders to adjust their transmission rates. This method differs in a very important way from congestion control in which a congested network component just drops packets - the most commonly used method. It is clearly advantageous for the links in the network to communicate with the end users about the network capacity, rather than the users unilaterally picking a transmission rate. The components in the middle of the network, not the end users, have information about the capacity and traffic in the network. The author experiments with three different algorithms for calculating the control rate to feed back to the users. All of the algorithms exhibit problems in the form of large queues when simulated with a configuration modeling the dynamics of a packet-voice system. However, the problems are not with the algorithms themselves, but with the fact that feedback takes time. If the network steady-state utilization is low enough that it can absorb transients in the traffic through it, then the large queues disappear. If the users are modified to start sending slowly, to allow the network to adapt to a new flow without causing congestion, a greater portion of the network's bandwidth can be used.

  11. Increasing Intelligence in Inter-Vehicle Communications to Reduce Traffic Congestions: Experiments in Urban and Highway Environments.

    PubMed

    Meneguette, Rodolfo I; Filho, Geraldo P R; Guidoni, Daniel L; Pessin, Gustavo; Villas, Leandro A; Ueyama, Jó

    2016-01-01

    Intelligent Transportation Systems (ITS) rely on Inter-Vehicle Communication (IVC) to streamline the operation of vehicles by managing vehicle traffic, assisting drivers with safety and sharing information, as well as providing appropriate services for passengers. Traffic congestion is an urban mobility problem, which causes stress to drivers and economic losses. In this context, this work proposes a solution for the detection, dissemination and control of congested roads based on inter-vehicle communication, called INCIDEnT. The main goal of the proposed solution is to reduce the average trip time, CO emissions and fuel consumption by allowing motorists to avoid congested roads. The simulation results show that our proposed solution leads to short delays and a low overhead. Moreover, it is efficient with regard to the coverage of the event and the distance to which the information can be propagated. The findings of the investigation show that the proposed solution leads to (i) high hit rate in the classification of the level of congestion, (ii) a reduction in average trip time, (iii) a reduction in fuel consumption, and (iv) reduced CO emissions.

  12. 14 CFR 137.51 - Operation over congested areas: General.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Operation over congested areas: General. 137.51 Section 137.51 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS...

  13. 14 CFR 103.15 - Operations over congested areas.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Operations over congested areas. 103.15 Section 103.15 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES ULTRALIGHT VEHICLES Operating Rules § 103.15 Operations...

  14. Nuclear angiography in a dog with congestive cardiomyopathy

    SciTech Connect

    Lippert, A.C.; Twardock, A.R.; Gelberg, H.B.

    1986-03-01

    Nuclear angiography was used as a diagnostic aid and in monitoring the clinical course of a case of congestive cardiomyopathy in a dog. Serial examinations revealed progressively deteriorating values for left ventricular ejection fraction before the dog's death. This noninvasive technique can be an alternative to echocardiography for the evaluation of cardiac performance.

  15. Controlling congestion on complex networks: fairness, efficiency and network structure.

    PubMed

    Buzna, Ľuboš; Carvalho, Rui

    2017-08-22

    We consider two elementary (max-flow and uniform-flow) and two realistic (max-min fairness and proportional fairness) congestion control schemes, and analyse how the algorithms and network structure affect throughput, the fairness of flow allocation, and the location of bottleneck edges. The more realistic proportional fairness and max-min fairness algorithms have similar throughput, but path flow allocations are more unequal in scale-free than in random regular networks. Scale-free networks have lower throughput than their random regular counterparts in the uniform-flow algorithm, which is favoured in the complex networks literature. We show, however, that this relation is reversed on all other congestion control algorithms for a region of the parameter space given by the degree exponent γ and average degree 〈k〉. Moreover, the uniform-flow algorithm severely underestimates the network throughput of congested networks, and a rich phenomenology of path flow allocations is only present in the more realistic α-fair family of algorithms. Finally, we show that the number of paths passing through an edge characterises the location of a wide range of bottleneck edges in these algorithms. Such identification of bottlenecks could provide a bridge between the two fields of complex networks and congestion control.

  16. Cooperative multiagent congestion control for high-speed networks.

    PubMed

    Hwang, Kao-Shing; Tan, Shun-Wen; Hsiao, Ming-Chang; Wu, Cheng-Shong

    2005-04-01

    An adaptive multiagent reinforcement learning method for solving congestion control problems on dynamic high-speed networks is presented. Traditional reactive congestion control selects a source rate in terms of the queue length restricted to a predefined threshold. However, the determination of congestion threshold and sending rate is difficult and inaccurate due to the propagation delay and the dynamic nature of the networks. A simple and robust cooperative multiagent congestion controller (CMCC), which consists of two subsystems: a long-term policy evaluator, expectation-return predictor and a short-term rate selector composed of action-value evaluator and stochastic action selector elements has been proposed to solve the problem. After receiving cooperative reinforcement signals generated by a cooperative fuzzy reward evaluator using game theory, CMCC takes the best action to regulate source flow with the features of high throughput and low packet loss rate. By means of learning procedures, CMCC can learn to take correct actions adaptively under time-varying environments. Simulation results showed that the proposed approach can promote the system utilization and decrease packet losses simultaneously.

  17. Continuous ultrafiltration for congestive heart failure: the CUORE trial.

    PubMed

    Marenzi, Giancarlo; Muratori, Manuela; Cosentino, Eugenio R; Rinaldi, Elisa R; Donghi, Valeria; Milazzo, Valentina; Ferramosca, Emiliana; Borghi, Claudio; Santoro, Antonio; Agostoni, Piergiuseppe

    2014-05-01

    Background: There are limited data comparing ultrafiltration with standard medical therapy as first-line treatment in patients with severe congestive heart failure (HF). We compared ultrafiltration and conventional therapy in patients hospitalized for HF and overt fluid overload.Methods and Results: Fifty-six patients with congestive HF were randomized to receive standard medical therapy (control group; n = 29) or ultrafiltration (ultrafiltration group; = 27). The primary endpoint of the study was rehospitalizations for congestive HF during a 1-year follow-up. Despite similar body weight reduction at hospital discharge in the 2 groups (7.5 ± 4.5 and 7.9 ± 5.0 kg, respectively;P = .75), a lower incidence of rehospitalizations for HF was observed in the ultrafiltration-treated patients during the following year (hazard ratio 0.14, 95% confidence interval 0.04-0.48; P = .002).Ultrafiltration-induced benefit was associated with a more stable renal function, unchanged furosemide dose, and lower B-type natriuretic peptide levels. At 1 year, 7 deaths (30%) occurred in the ultrafiltration group and 11 (44%) in the control group (P = .33).Conclusions: In HF patients with severe fluid overload, first-line treatment with ultrafiltration is associated with a prolonged clinical stabilization and a greater freedom from rehospitalization for congestive HF.

  18. Intramembrane congestion effects on lysenin channel voltage-induced gating.

    PubMed

    Krueger, Eric; Bryant, Sheenah; Shrestha, Nisha; Clark, Tyler; Hanna, Charles; Pink, David; Fologea, Daniel

    2016-03-01

    All cell membranes are packed with proteins. The ability to investigate the regulatory mechanisms of protein channels in experimental conditions mimicking their congested native environment is crucial for understanding the environmental physicochemical cues that may fundamentally contribute to their functionality in natural membranes. Here we report on investigations of the voltage-induced gating of lysenin channels in congested conditions experimentally achieved by increasing the number of channels inserted into planar lipid membranes. Typical electrophysiology measurements reveal congestion-induced changes to the voltage-induced gating, manifested as a significant reduction of the response to external voltage stimuli. Furthermore, we demonstrate a similar diminished voltage sensitivity for smaller populations of channels by reducing the amount of sphingomyelin in the membrane. Given lysenin's preference for targeting lipid rafts, this result indicates the potential role of the heterogeneous organization of the membrane in modulating channel functionality. Our work indicates that local congestion within membranes may alter the energy landscape and the kinetics of conformational changes of lysenin channels in response to voltage stimuli. This level of understanding may be extended to better characterize the role of the specific membrane environment in modulating the biological functionality of protein channels in health and disease.

  19. Intramembrane congestion effects on lysenin channel voltage-induced gating

    PubMed Central

    Krueger, Eric; Bryant, Sheenah; Shrestha, Nisha; Clark, Tyler; Hanna, Charles; Pink, David; Fologea, Daniel

    2016-01-01

    All cell membranes are packed with proteins. The ability to investigate the regulatory mechanisms of protein channels in experimental conditions mimicking their congested native environment is crucial for understanding the environmental physicochemical cues that may fundamentally contribute to their functionality in natural membranes. Here we report on investigations of the voltage-induced gating of lysenin channels in congested conditions experimentally achieved by increasing the number of channels inserted into planar lipid membranes. Typical electrophysiology measurements reveal congestion-induced changes to the voltage-induced gating, manifested as a significant reduction of the response to external voltage stimuli. Furthermore, we demonstrate a similar diminished voltage sensitivity for smaller populations of channels by reducing the amount of sphingomyelin in the membrane. Given lysenin’s preference for targeting lipid rafts, this result indicates the potential role of the heterogeneous organization of the membrane in modulating channel functionality. Our work indicates that local congestion within membranes may alter the energy landscape and the kinetics of conformational changes of lysenin channels in response to voltage stimuli. This level of understanding may be extended to better characterize the role of the specific membrane environment in modulating the biological functionality of protein channels in health and disease. PMID:26695013

  20. 23 CFR 450.320 - Congestion management process in transportation management areas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... evaluation of the effectiveness of congestion reduction and mobility enhancement strategies for the movement... cooperatively developed and implemented metropolitan-wide strategy, of new and existing transportation... travel demand reduction and operational management strategies. (b) The development of a congestion...

  1. 23 CFR 450.320 - Congestion management process in transportation management areas.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... evaluation of the effectiveness of congestion reduction and mobility enhancement strategies for the movement... cooperatively developed and implemented metropolitan-wide strategy, of new and existing transportation... travel demand reduction and operational management strategies. (b) The development of a congestion...

  2. 23 CFR 450.320 - Congestion management process in transportation management areas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... evaluation of the effectiveness of congestion reduction and mobility enhancement strategies for the movement... cooperatively developed and implemented metropolitan-wide strategy, of new and existing transportation... travel demand reduction and operational management strategies. (b) The development of a congestion...

  3. 23 CFR 450.320 - Congestion management process in transportation management areas.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... evaluation of the effectiveness of congestion reduction and mobility enhancement strategies for the movement... cooperatively developed and implemented metropolitan-wide strategy, of new and existing transportation... travel demand reduction and operational management strategies. (b) The development of a congestion...

  4. Increased walking variability in elderly persons with congestive heart failure

    NASA Technical Reports Server (NTRS)

    Hausdorff, J. M.; Forman, D. E.; Ladin, Z.; Goldberger, A. L.; Rigney, D. R.; Wei, J. Y.

    1994-01-01

    OBJECTIVES: To determine the effects of congestive heart failure on a person's ability to walk at a steady pace while ambulating at a self-determined rate. SETTING: Beth Israel Hospital, Boston, a primary and tertiary teaching hospital, and a social activity center for elderly adults living in the community. PARTICIPANTS: Eleven elderly subjects (aged 70-93 years) with well compensated congestive heart failure (NY Heart Association class I or II), seven elderly subjects (aged 70-79 years) without congestive heart failure, and 10 healthy young adult subjects (aged 20-30 years). MEASUREMENTS: Subjects walked for 8 minutes on level ground at their own selected walking rate. Footswitches were used to measure the time between steps. Step rate (steps/minute) and step rate variability were calculated for the entire walking period, for 30 seconds during the first minute of the walk, for 30 seconds during the last minute of the walk, and for the 30-second period when each subject's step rate variability was minimal. Group means and 5% and 95% confidence intervals were computed. MAIN RESULTS: All measures of walking variability were significantly increased in the elderly subjects with congestive heart failure, intermediate in the elderly controls, and lowest in the young subjects. There was no overlap between the three groups using the minimal 30-second variability (elderly CHF vs elderly controls: P < 0.001, elderly controls vs young: P < 0.001), and no overlap between elderly subjects with and without congestive heart failure when using the overall variability. For all four measures, there was no overlap in any of the confidence intervals, and all group means were significantly different (P < 0.05).

  5. Increased walking variability in elderly persons with congestive heart failure

    NASA Technical Reports Server (NTRS)

    Hausdorff, J. M.; Forman, D. E.; Ladin, Z.; Goldberger, A. L.; Rigney, D. R.; Wei, J. Y.

    1994-01-01

    OBJECTIVES: To determine the effects of congestive heart failure on a person's ability to walk at a steady pace while ambulating at a self-determined rate. SETTING: Beth Israel Hospital, Boston, a primary and tertiary teaching hospital, and a social activity center for elderly adults living in the community. PARTICIPANTS: Eleven elderly subjects (aged 70-93 years) with well compensated congestive heart failure (NY Heart Association class I or II), seven elderly subjects (aged 70-79 years) without congestive heart failure, and 10 healthy young adult subjects (aged 20-30 years). MEASUREMENTS: Subjects walked for 8 minutes on level ground at their own selected walking rate. Footswitches were used to measure the time between steps. Step rate (steps/minute) and step rate variability were calculated for the entire walking period, for 30 seconds during the first minute of the walk, for 30 seconds during the last minute of the walk, and for the 30-second period when each subject's step rate variability was minimal. Group means and 5% and 95% confidence intervals were computed. MAIN RESULTS: All measures of walking variability were significantly increased in the elderly subjects with congestive heart failure, intermediate in the elderly controls, and lowest in the young subjects. There was no overlap between the three groups using the minimal 30-second variability (elderly CHF vs elderly controls: P < 0.001, elderly controls vs young: P < 0.001), and no overlap between elderly subjects with and without congestive heart failure when using the overall variability. For all four measures, there was no overlap in any of the confidence intervals, and all group means were significantly different (P < 0.05).

  6. 23 CFR 972.214 - Federal lands congestion management system (CMS).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 23 Highways 1 2013-04-01 2013-04-01 false Federal lands congestion management system (CMS). 972... § 972.214 Federal lands congestion management system (CMS). (a) For purposes of this section, congestion... interference. For those FWS transportation systems that require a CMS, in both metropolitan and...

  7. 23 CFR 972.214 - Federal lands congestion management system (CMS).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 23 Highways 1 2014-04-01 2014-04-01 false Federal lands congestion management system (CMS). 972... § 972.214 Federal lands congestion management system (CMS). (a) For purposes of this section, congestion... interference. For those FWS transportation systems that require a CMS, in both metropolitan and...

  8. 23 CFR 450.320 - Congestion management process in transportation management areas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Congestion management process in transportation... Programming § 450.320 Congestion management process in transportation management areas. (a) The transportation planning process in a TMA shall address congestion management through a process that provides for safe...

  9. Extracorporeal versus peritoneal ultrafiltration in diuretic-resistant congestive heart failure – a review

    PubMed Central

    Wańkowicz, Zofia; Próchnicka, Agnieszka; Olszowska, Anna; Baczyński, Daniel; Krzesiński, Paweł; Dziuk, Mirosław

    2011-01-01

    Summary Diuretic-resistant congestive heart failure in the form of type 2 cardiorenal syndrome is a problem of growing significance in everyday clinical practice because of high morbidity and mortality. There has been scant progress in the treatment of overhydration, the main cause of symptoms in this group of patients. The aim of our review is to present recent advances in the ultrafiltration therapy of congestive heart failure, with special attention to the new dedicated device for extracorporeal isolated ultrafiltration, as well as modifications of peritoneal dialysis in the form of peritoneal ultrafiltration with icodextrin solution and incremental peritoneal dialysis. Technical and clinical features, costs and potential risks of available devices for isolated ultrafiltration are presented. This method should be reserved for patients with true diuretic resistance as part of a more complex strategy aiming at the adequate control of fluid retention. Peritoneal ultrafiltration is presented as a viable alternative to extracorporeal ultrafiltration because of medical and psychosocial benefits of home-based therapy, lower costs and more effective daily ultrafiltration. In conclusion, large, properly randomized and controlled clinical trials with long-term follow-up will be essential in assessing the logistics and cost-effectiveness of both methods. Most importantly, however, they should be able to evaluate the impact of both methods on preservation of renal function and delaying the progression of heart failure by interrupting the vicious circle of cardiorenal syndrome. Our review is supplemented with the case report of the use of peritoneal ultrafiltration with a single 12-hour nighttime icodextrin exchange as a life-saving procedure in a patient with congestive heart failure resistant to pharmacological treatment. PMID:22129914

  10. Extracorporeal versus peritoneal ultrafiltration in diuretic-resistant congestive heart failure--a review.

    PubMed

    Wańkowicz, Zofia; Próchnicka, Agnieszka; Olszowska, Anna; Baczyński, Daniel; Krzesiński, Paweł; Dziuk, Mirosław

    2011-12-01

    Diuretic-resistant congestive heart failure in the form of type 2 cardiorenal syndrome is a problem of growing significance in everyday clinical practice because of high morbidity and mortality. There has been scant progress in the treatment of overhydration, the main cause of symptoms in this group of patients. The aim of our review is to present recent advances in the ultrafiltration therapy of congestive heart failure, with special attention to the new dedicated device for extracorporeal isolated ultrafiltration, as well as modifications of peritoneal dialysis in the form of peritoneal ultrafiltration with icodextrin solution and incremental peritoneal dialysis. Technical and clinical features, costs and potential risks of available devices for isolated ultrafiltration are presented. This method should be reserved for patients with true diuretic resistance as part of a more complex strategy aiming at the adequate control of fluid retention. Peritoneal ultrafiltration is presented as a viable alternative to extracorporeal ultrafiltration because of medical and psychosocial benefits of home-based therapy, lower costs and more effective daily ultrafiltration. In conclusion, large, properly randomized and controlled clinical trials with long-term follow-up will be essential in assessing the logistics and cost-effectiveness of both methods. Most importantly, however, they should be able to evaluate the impact of both methods on preservation of renal function and delaying the progression of heart failure by interrupting the vicious circle of cardiorenal syndrome. Our review is supplemented with the case report of the use of peritoneal ultrafiltration with a single 12-hour nighttime icodextrin exchange as a life-saving procedure in a patient with congestive heart failure resistant to pharmacological treatment.

  11. Congestive heart failure in 6 African grey parrots (Psittacus e erithacus).

    PubMed

    Juan-Sallés, C; Soto, S; Garner, M M; Montesinos, A; Ardiaca, M

    2011-05-01

    Six African grey parrots (Psittacus e erithacus) were diagnosed with cardiomyopathy and congestive heart failure based on gross and microscopic findings. Ages ranged from 15 days to 8 years, and 5 of 6 parrots were either neonates or juveniles at the time of diagnosis. Two neonates and 2 juveniles came from the same breeding aviary; the 2 juveniles were born to the same breeding pair. The 2 other parrots were kept as pets. Clinical signs included distention of the coelomic cavity (4 of 6), rales (3 of 6), weakness (4 of 6), bradyarrhythmia (1 of 6), growth retardation (1 of 6), crop stasis (1 of 6), and regurgitation (1 of 6). Three parrots were euthanized and 3 died. Gross findings included cardiomegaly due to biventricular, right-, or left-sided cardiomyopathy (6 of 6); coelomic effusion (6 of 6); whitish or yellow foci in the liver (6 of 6); atrophy of the liver (particularly, the left lobe; 5 of 6); reddened or grey lungs (5 of 6); subcutaneous edema (2 of 6); hydropericardium (1 of 6); and bilateral thyroid gland enlargement (1 of 6). Relevant microscopic findings included passive hepatic congestion (6 of 6) and pulmonary congestion (2 of 6), lymphocytic thyroiditis (2 of 6), and diffuse thyroid follicular hyperplasia (2 of 6). Microscopically, the heart was unremarkable (2 of 6) or had mild lymphocytic myocarditis (2 of 6), mild multifocal cytoplasmic vacuolation of cardiomyocytes (2 of 6), mild lymphocytic myocardial (Purkinje cell) ganglioneuritis (1 of 6), and mild multifocal interstitial fibrosis and nuclear hypertrophy of cardiomyocytes (1 of 6). One parrot had concurrent proventricular dilatation disease (systemic ganglioneuritis). The cause of cardiomyopathy in these parrots was not determined.

  12. Myocardial myoglobin deficiency in various animal models of congestive heart failure.

    PubMed

    O'Brien, P J; O'Grady, M; McCutcheon, L J; Shen, H; Nowack, L; Horne, R D; Mirsalimi, S M; Julian, R J; Grima, E A; Moe, G W

    1992-07-01

    Myoglobin is known to protect the mechanical function of the heart from hypoxia by acting as a sarcoplasmic oxygen reservoir and shuttle. We postulated a role for myoglobin in the pathogenesis of congestive heart failure. Several models of congestive heart failure were employed to test the hypothesis, including spontaneous inherited dilated cardiomyopathy in Doberman Pinschers, and heart failure produced by rapid ventricular pacing in dogs, volume overload in chickens and furazolidone toxicity in turkeys. Myocardial myoglobin was decreased by approximately 50% for all models (P less than 0.05). In Doberman Pinschers dogs which are predisposed to the development of dilated cardiomyopathy and have mild subclinical depression of cardiac performance, myocardial myoglobin (1.05 +/- 0.22 mg/g) is approximately 50% decreased compared to healthy mongrel dogs (2.15 +/- 0.52 mg/g), approximately twice as much as dobermans with heart failure (0.47 +/- 0.25 mg/g) but similar to the concentration found in dogs paced to heart failure (1.09 +/- 0.34 mg/g). Myocardium from poultry had remarkably decreased myoglobin compared to mammals (34 +/- 4 micrograms/g) with heart failure produced either by furazolidone or salt toxicity causing a further 50% reduction. In the canine models of heart failure, myocardial myoglobin concentration was demonstrated to be correlated with biochemical and physiological indicators of myocardial performance, namely, mitochondrial and sarcoplasmic reticular ATPase activities, and cardiac output, systemic vascular resistance, pulmonary capillary wedge pressure and mean arterial pressure, respectively. Our data implicates a role for myoglobin deficiency in the pathogenesis of congestive heart failure and in the predisposition of doberman pinschers to dilated cardiomyopathy.

  13. Relationship between venous pressure and tissue volume during venous congestion plethysmography in man.

    PubMed

    Christ, F; Gamble, J; Baschnegger, H; Gartside, I B

    1997-09-01

    1. Venous congestion strain-gauge plethysmography enables the non-invasive assessment of arterial blood flow, fluid filtration capacity (Kf), venous pressure (Pv) and isovolumetric venous pressure (Pvi) in man. One of the major assumptions of this technique, that cuff pressure (Pcuff) applied to the limb equals Pv at the level of the strain gauge, was tested in this study. 2. In nine healthy male volunteers (mean age, 29.3 +/- 1.2 years) the saphenous vein was cannulated with an 18-gauge catheter proximal to the medial malleolus. The subjects were supine and Pv was continuously measured during the application of small step (8-10 mmHg) increases in congestion Pcuff (up to 70 mmHg). Pcuff, changes in limb circumference and Pv were recorded by computer for off-line analysis. Since the determination of Kf is influenced by the changes in plasma oncotic pressure, venous blood samples were obtained at the start of the study, when Pcuff was raised to 30 mmHg and again to 65 mmHg and 4 min after deflation of the cuff. 3. The relationship between Pv and Pcuff was linear over the range of 10-70 mmHg (n = 9, 69 measurements, slope 0.91, r = 0.97, P < 0.001). The non-invasively measured calf Pv, based on the intercept of the relationship between the vascular compliance component (Va) and Pcuff, was 8.0 +/- 0.4 mmHg, which was not significantly different from the corrected invasively measured Pv value of 8.8 +/- 0.3 mmHg (P = 0.08). 4. Venous blood lactate and haemoglobin concentrations, as well as colloid osmotic pressure, total protein and albumin concentrations were unchanged throughout the protocol, whereas significant decreases in PO2 and blood glucose concentration were observed when Pcuff reached 65 mmHg. Assuming a constant oxygen consumption, this may suggest a reduction in tissue perfusion. 5. This study demonstrates the close correlation between Pcuff and Pv in the saphenous vein. Since the small congestion Pcuff step protocol does not cause significant increase in

  14. How congestion shapes cities: from mobility patterns to scaling

    PubMed Central

    Louf, Rémi; Barthelemy, Marc

    2014-01-01

    The recent availability of data for cities has allowed scientists to exhibit scalings which present themselves in the form of a power-law dependence on population of various socio-economical and structural indicators. We propose here a stochastic theory of urban growth which accounts for some of the observed scalings and we confirm these predictions on US and OECD empirical data. In particular, we show that the dependence on population size of the total number of miles driven daily, the total length of the road network, the total traffic delay, the total consumption of gasoline, the quantity of CO2 emitted and the relation between area and population of cities, are all governed by a single parameter which characterizes the sensitivity to congestion. Our results suggest that diseconomies associated with congestion scale superlinearly with population size, implying that –despite polycentrism– cities whose transportation infrastructure rely heavily on traffic sensitive modes are unsustainable. PMID:24990624

  15. TCP congestion control in input-queued crossbar switch

    NASA Astrophysics Data System (ADS)

    Zheng, Hongyun; Zhao, Yongxiang; Chen, Changjia

    2005-02-01

    In this paper, we consider congestion control in input queued crossbar switch environment where each input port with finite buffer space while TCP protocol is employed for end-to-end congestion control. We find that it is impossible to achieve efficiency and fairness among TCP flows at the same time only by queue management. Then we propose a scheme of hFS&rEDF, which combine heuristic fair switch arbitration (hFS) and queue management policy of early drop front randomly (rEDF). In our proposed scheme, switch arbitration strategy of hFS unevenly allows input ports to transfer packets to output ports while packets at head of any other input ports involved in conflicts have to be dropped by the policy of rEDF with a probability. Simulation results prove that our proposed scheme can achieve better tradeoff between throughput and fairness.

  16. How congestion shapes cities: from mobility patterns to scaling

    NASA Astrophysics Data System (ADS)

    Louf, Rémi; Barthelemy, Marc

    2014-07-01

    The recent availability of data for cities has allowed scientists to exhibit scalings which present themselves in the form of a power-law dependence on population of various socio-economical and structural indicators. We propose here a stochastic theory of urban growth which accounts for some of the observed scalings and we confirm these predictions on US and OECD empirical data. In particular, we show that the dependence on population size of the total number of miles driven daily, the total length of the road network, the total traffic delay, the total consumption of gasoline, the quantity of CO2 emitted and the relation between area and population of cities, are all governed by a single parameter which characterizes the sensitivity to congestion. Our results suggest that diseconomies associated with congestion scale superlinearly with population size, implying that -despite polycentrism- cities whose transportation infrastructure rely heavily on traffic sensitive modes are unsustainable.

  17. How congestion shapes cities: from mobility patterns to scaling.

    PubMed

    Louf, Rémi; Barthelemy, Marc

    2014-07-03

    The recent availability of data for cities has allowed scientists to exhibit scalings which present themselves in the form of a power-law dependence on population of various socio-economical and structural indicators. We propose here a stochastic theory of urban growth which accounts for some of the observed scalings and we confirm these predictions on US and OECD empirical data. In particular, we show that the dependence on population size of the total number of miles driven daily, the total length of the road network, the total traffic delay, the total consumption of gasoline, the quantity of CO2 emitted and the relation between area and population of cities, are all governed by a single parameter which characterizes the sensitivity to congestion. Our results suggest that diseconomies associated with congestion scale superlinearly with population size, implying that -despite polycentrism- cities whose transportation infrastructure rely heavily on traffic sensitive modes are unsustainable.

  18. Acute abdomen due to ovarian congestion: a fallopian tube accompanied by a paratubal cyst, coiling tightly round the ovary.

    PubMed

    Kaido, Yoshitaka; Kikuchi, Akihiko; Kanasugi, Tomonobu; Fukushima, Akimune; Sugiyama, Toru

    2013-01-01

    We experienced an unreported rare case with an adnexal mass causing severe acute abdomen during pregnancy. A 30-year-old Japanese pregnant woman was transported to our hospital for her right lower abdominal pain at 30 weeks of gestation. Magnetic resonance imaging and ultrasound demonstrated a cyst measuring 3-4 cm in diameter adjacent to the right ovary, and a parovarian cyst was considered to be the most probable diagnosis. We strongly suspected torsion of the ovarian pedicle or fallopian tube in conjunction with her clinical symptoms. Laparotomy revealed that the elongated right fallopian tube accompanied by a paratubal cyst was coiling tightly 2.5 times round the right ovary, causing apparent congestion and enlargement of the right ovary. Soon after we released the congested right ovary from the coiling of the fallopian tube, the congestion subsided. The postoperative course was favorable, and pregnancy and delivery were uneventful. © 2012 The Authors. Journal of Obstetrics and Gynaecology Research © 2012 Japan Society of Obstetrics and Gynecology.

  19. Thyrotropin-secreting pituitary tumor presenting with congestive heart failure and good response to dopaminergic agonist cabergoline.

    PubMed

    Kao, Yu-Hsi; Chang, Tien-Jyun; Huang, Tien-Shang

    2013-11-01

    Hyperthyroidism is an important inducing factor in patients with atrial fibrillation, and may trigger heart failure. Thyrotropin (thyroid stimulating hormone, TSH)-secreting pituitary tumors are rare causes of hyperthyroidism. Here, we report a 66-year-old man with a pituitary TSH-secreting tumor who presented with hyperthyroidism and congestive heart failure. Endonasal trans-sphenoidal pituitary adenomectomy was performed. After the operation, the symptoms of hyperthyroidism and congestive heart failure were relieved, associated with normalization of thyroid function tests. Unfortunately, hand tremor and progressively elevated free T4 and TSH concentrations recurred 5 months after surgery. A dopaminergic agonist, cabergoline was administered and euthyroidism was restored for at least 11 months.

  20. Application of Epidemiology Model on Complex Networks in Propagation Dynamics of Airspace Congestion.

    PubMed

    Dai, Xiaoxu; Hu, Minghua; Tian, Wen; Xie, Daoyi; Hu, Bin

    2016-01-01

    This paper presents a propagation dynamics model for congestion propagation in complex networks of airspace. It investigates the application of an epidemiology model to complex networks by comparing the similarities and differences between congestion propagation and epidemic transmission. The model developed satisfies the constraints of actual motion in airspace, based on the epidemiology model. Exploiting the constraint that the evolution of congestion cluster in the airspace is always dynamic and heterogeneous, the SIR epidemiology model (one of the classical models in epidemic spreading) with logistic increase is applied to congestion propagation and shown to be more accurate in predicting the evolution of congestion peak than the model based on probability, which is common to predict the congestion propagation. Results from sample data show that the model not only predicts accurately the value and time of congestion peak, but also describes accurately the characteristics of congestion propagation. Then, a numerical study is performed in which it is demonstrated that the structure of the networks have different effects on congestion propagation in airspace. It is shown that in regions with severe congestion, the adjustment of dissipation rate is more significant than propagation rate in controlling the propagation of congestion.

  1. Autonomous Distributed Congestion Control Scheme in WCDMA Network

    NASA Astrophysics Data System (ADS)

    Ahmad, Hafiz Farooq; Suguri, Hiroki; Choudhary, Muhammad Qaisar; Hassan, Ammar; Liaqat, Ali; Khan, Muhammad Umer

    Wireless technology has become widely popular and an important means of communication. A key issue in delivering wireless services is the problem of congestion which has an adverse impact on the Quality of Service (QoS), especially timeliness. Although a lot of work has been done in the context of RRM (Radio Resource Management), the deliverance of quality service to the end user still remains a challenge. Therefore there is need for a system that provides real-time services to the users through high assurance. We propose an intelligent agent-based approach to guarantee a predefined Service Level Agreement (SLA) with heterogeneous user requirements for appropriate bandwidth allocation in QoS sensitive cellular networks. The proposed system architecture exploits Case Based Reasoning (CBR) technique to handle RRM process of congestion management. The system accomplishes predefined SLA through the use of Retrieval and Adaptation Algorithm based on CBR case library. The proposed intelligent agent architecture gives autonomy to Radio Network Controller (RNC) or Base Station (BS) in accepting, rejecting or buffering a connection request to manage system bandwidth. Instead of simply blocking the connection request as congestion hits the system, different buffering durations are allocated to diverse classes of users based on their SLA. This increases the opportunity of connection establishment and reduces the call blocking rate extensively in changing environment. We carry out simulation of the proposed system that verifies efficient performance for congestion handling. The results also show built-in dynamism of our system to cater for variety of SLA requirements.

  2. Self-Tuned Congestion Control for Multiprocessor Networks

    DTIC Science & Technology

    2005-01-01

    multiprocessor networks, including virtual cut-through [15] networks and wormhole networks [6, 5]. However, in this paper we evaluate the technique in the...context of wormhole switched, k-ary,n-cube networks. Simulation results for a 16-ary,2-cube (256 node net- work) show that our congestion control...through the net- work. Each packet is composed of flits (flow control units) that are transferred between network nodes.1 Both wormhole routing and cut

  3. Optimal Use of Beta-Blockers for Congestive Heart Failure.

    PubMed

    Lee, Hae-Young; Baek, Sang Hong

    2016-01-01

    Beta-blockers are the cornerstone treatment for congestive heart failure (HF). Current HF guidelines commonly recommend β-blockers for the treatment of HF with reduced left ventricular ejection fraction (LVEF). The effect of β-blockers, however, is less clear for HF patients with preserved LVEF, unstable severe acute HF, or right ventricular failure. This review summarizes the effect of β-blockers in various clinical situations and suggests a strategy for optimal use. (Circ J 2016; 80: 565-571).

  4. Congestion Control and Fairness in Wireless Sensor Networks

    DTIC Science & Technology

    2010-04-01

    RCRT uses end-to-end explicit loss recovery by implementing a NACK based scheme. Furthermore, RCRT places all congestion detection and rate...gateway nodes, we make use of the broadcast nature of the wireless medium, which enables a child node to overhear transmissions of its parent. When...the broadcast nature of the wireless medium, enabling a child node to overhear transmission of its parent. Thus, when the minimum bandwidth

  5. The use of B-type natriuretic peptide to diagnose congestive heart failure.

    PubMed

    Gray, Jeffery R

    2006-01-01

    This paper explains the background and current use of B-type natriuretic peptide (BNP) assays to differentiate congestive heart failure (CHF) from other causes of dyspnea. With a large and growing elderly population, CHF is being diagnosed much more often in emergency rooms in the United States. Doctors need a way to quickly distinguish whether a patient with respiratory distress is suffering from cardiac insufficiency or another etiology. BNP is released from the ventricles in response cardiac overload from CHF or some other form of left ventricular systolic dysfunction. Therefore, the detection and measurement of BNP is a fast and accurate method of determining if CHF is the cause of a patient's breathing difficulties.

  6. Predictability of Road Traffic and Congestion in Urban Areas

    PubMed Central

    Wang, Jingyuan; Mao, Yu; Li, Jing; Xiong, Zhang; Wang, Wen-Xu

    2015-01-01

    Mitigating traffic congestion on urban roads, with paramount importance in urban development and reduction of energy consumption and air pollution, depends on our ability to foresee road usage and traffic conditions pertaining to the collective behavior of drivers, raising a significant question: to what degree is road traffic predictable in urban areas? Here we rely on the precise records of daily vehicle mobility based on GPS positioning device installed in taxis to uncover the potential daily predictability of urban traffic patterns. Using the mapping from the degree of congestion on roads into a time series of symbols and measuring its entropy, we find a relatively high daily predictability of traffic conditions despite the absence of any priori knowledge of drivers' origins and destinations and quite different travel patterns between weekdays and weekends. Moreover, we find a counterintuitive dependence of the predictability on travel speed: the road segment associated with intermediate average travel speed is most difficult to be predicted. We also explore the possibility of recovering the traffic condition of an inaccessible segment from its adjacent segments with respect to limited observability. The highly predictable traffic patterns in spite of the heterogeneity of drivers' behaviors and the variability of their origins and destinations enables development of accurate predictive models for eventually devising practical strategies to mitigate urban road congestion. PMID:25849534

  7. Traffic Congestion Detection System through Connected Vehicles and Big Data

    PubMed Central

    Cárdenas-Benítez, Néstor; Aquino-Santos, Raúl; Magaña-Espinoza, Pedro; Aguilar-Velazco, José; Edwards-Block, Arthur; Medina Cass, Aldo

    2016-01-01

    This article discusses the simulation and evaluation of a traffic congestion detection system which combines inter-vehicular communications, fixed roadside infrastructure and infrastructure-to-infrastructure connectivity and big data. The system discussed in this article permits drivers to identify traffic congestion and change their routes accordingly, thus reducing the total emissions of CO2 and decreasing travel time. This system monitors, processes and stores large amounts of data, which can detect traffic congestion in a precise way by means of a series of algorithms that reduces localized vehicular emission by rerouting vehicles. To simulate and evaluate the proposed system, a big data cluster was developed based on Cassandra, which was used in tandem with the OMNeT++ discreet event network simulator, coupled with the SUMO (Simulation of Urban MObility) traffic simulator and the Veins vehicular network framework. The results validate the efficiency of the traffic detection system and its positive impact in detecting, reporting and rerouting traffic when traffic events occur. PMID:27136548

  8. RATE-ADJUSTMENT ALGORITHM FOR AGGREGATE TCP CONGESTION CONTROL

    SciTech Connect

    P. TINNAKORNSRISUPHAP, ET AL

    2000-09-01

    The TCP congestion-control mechanism is an algorithm designed to probe the available bandwidth of the network path that TCP packets traverse. However, it is well-known that the TCP congestion-control mechanism does not perform well on networks with a large bandwidth-delay product due to the slow dynamics in adapting its congestion window, especially for short-lived flows. One promising solution to the problem is to aggregate and share the path information among TCP connections that traverse the same bottleneck path, i.e., Aggregate TCP. However, this paper shows via a queueing analysis of a generalized processor-sharing (GPS) queue with regularly-varying service time that a simple aggregation of local TCP connections together into a single aggregate TCP connection can result in a severe performance degradation. To prevent such a degradation, we introduce a rate-adjustment algorithm. Our simulation confirms that by utilizing our rate-adjustment algorithm on aggregate TCP, connections which would normally receive poor service achieve significant performance improvements without penalizing connections which already receive good service.

  9. Congestive heart failure detection using random forest classifier.

    PubMed

    Masetic, Zerina; Subasi, Abdulhamit

    2016-07-01

    Automatic electrocardiogram (ECG) heartbeat classification is substantial for diagnosing heart failure. The aim of this paper is to evaluate the effect of machine learning methods in creating the model which classifies normal and congestive heart failure (CHF) on the long-term ECG time series. The study was performed in two phases: feature extraction and classification phase. In feature extraction phase, autoregressive (AR) Burg method is applied for extracting features. In classification phase, five different classifiers are examined namely, C4.5 decision tree, k-nearest neighbor, support vector machine, artificial neural networks and random forest classifier. The ECG signals were acquired from BIDMC Congestive Heart Failure and PTB Diagnostic ECG databases and classified by applying various experiments. The experimental results are evaluated in several statistical measures (sensitivity, specificity, accuracy, F-measure and ROC curve) and showed that the random forest method gives 100% classification accuracy. Impressive performance of random forest method proves that it plays significant role in detecting congestive heart failure (CHF) and can be valuable in expressing knowledge useful in medicine. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Congestion control for low-priority filler traffic

    NASA Astrophysics Data System (ADS)

    Ott, Brian A.; Warnky, Timothy; Liberatore, Vincenzo

    2003-08-01

    As the cost of Internet access rises and the amount of deployed bandwidth increases, a way to make efficient use of the oft-unused bandwidth is desired. Simply providing a lower priority for traffic than best effort allows this bandwidth to be used without noticeable interference with regular traffic. Because bursts of normal traffic are given priority over this background, or filler, traffic, a more aggressive congestion control protocol is called for in the filler traffic. In our paper, we compare numerous versions of TCP-like congestion control of our own design, over which to implement low-priority traffic, by using the unused bandwidth at any given time. These protocols are divided into six "classes," which differ by the core congestion control algorithm and use different constants. Using the ns-2 network simulator, we collected network traces using each of our protocols in different network configurations, with multiple parameters for each configuration. These configurations simulated high- and low-bandwidth and latency networks. We compared the resulting throughput and sharing - the cumulative variation of throughput over each stream, normalized by the total throughput over the link - to our chosen baseline, TCP Sack. Most of the basic algorithms performed as well as or better than Sack in a background traffic environment, especially in terms of throughput. Using features from multiple classes, we also designed a more complex protocol that performed better than Sack in almost every environment, and performed better than the other algorithms in general.

  11. Predictability of road traffic and congestion in urban areas.

    PubMed

    Wang, Jingyuan; Mao, Yu; Li, Jing; Xiong, Zhang; Wang, Wen-Xu

    2015-01-01

    Mitigating traffic congestion on urban roads, with paramount importance in urban development and reduction of energy consumption and air pollution, depends on our ability to foresee road usage and traffic conditions pertaining to the collective behavior of drivers, raising a significant question: to what degree is road traffic predictable in urban areas? Here we rely on the precise records of daily vehicle mobility based on GPS positioning device installed in taxis to uncover the potential daily predictability of urban traffic patterns. Using the mapping from the degree of congestion on roads into a time series of symbols and measuring its entropy, we find a relatively high daily predictability of traffic conditions despite the absence of any priori knowledge of drivers' origins and destinations and quite different travel patterns between weekdays and weekends. Moreover, we find a counterintuitive dependence of the predictability on travel speed: the road segment associated with intermediate average travel speed is most difficult to be predicted. We also explore the possibility of recovering the traffic condition of an inaccessible segment from its adjacent segments with respect to limited observability. The highly predictable traffic patterns in spite of the heterogeneity of drivers' behaviors and the variability of their origins and destinations enables development of accurate predictive models for eventually devising practical strategies to mitigate urban road congestion.

  12. Load Distribution in Congested Scale-Free Networks

    NASA Astrophysics Data System (ADS)

    Zheng, Jian-Feng; Gao, Zi-You; Fu, Bai-Bai

    In this work, we study the effects of scale-free topology and congestion on load distribution. Congestion effect can be described by link cost functions, which map link flows into travel times. Two different kinds of link's practical capacity (it is similar to link's capacity for transport) which is a parameter in link cost functions, i.e., uniform case and nonuniform case, are investigated. After introducing the effect of congestion, load distribution is typically discussed in Barábasi-Albert and Goh scale-free networks. In the uniform case, for Barábasi-Albert scale-free networks, we recover a power-law behavior for load distribution with a larger exponent, as compared with the distribution of betweenness centrality; for Goh scale-free networks, we also recover a power-law behavior and its exponent approaches to the exponent of degree distribution. While in the nonuniform case, the power-law behavior for load distribution may not always be conserved in both Barábasi-Albert and Goh scale-free networks. That is to say, different kinds of load distributions are obtained under different conditions. It may shed some light to study traffic dynamics on scale-free networks.

  13. Metabolic cardiology: an integrative strategy in the treatment of congestive heart failure.

    PubMed

    Sinatra, Stephen T

    2009-01-01

    Congestive heart failure (CHF) and dilated cardiomyopathy are life-threatening conditions in which the heart muscle is so weak that effective pulsatile action is compromised. Pulmonary vascular congestion and swelling in the lower extremities as well as in the liver and lining of the gastrointestinal tract frequently cause overwhelming symptoms and disability. Millions of Americans suffer from CHF, and more than 500,000 cases are diagnosed annually. Cardiovascular diseases such as hypertension with left ventricular hypertrophy, valvular heart disease, coronary artery disease, myocarditis, and various cardiomyopathies can lead to the progressive onset of CHF. The purpose of this communication article is to introduce metabolic cardiology as a vital therapeutic strategy utilizing nutritional biochemical interventions that preserve and promote adenosine triphosphate (ATP) production. Treatment options that incorporate metabolic interventions targeted to preserve energy substrates (D-ribose) or accelerate ATP turnover (L-carnitine and coenzyme Q10) are indicated for at-risk populations or patients at any stage of CHF. The integration of these metabolic supports provides the missing link in CHF treatment that has been eluding physicians for decades.

  14. Diagnosis and treatment of congestive heart failure secondary to dilated cardiomyopathy in a hedgehog.

    PubMed

    Delk, K W; Eshar, D; Garcia, E; Harkin, K

    2014-03-01

    A one-year-old African pygmy hedgehog (Atelerix albiventris) was evaluated for severe respiratory distress. Physical examination findings included marked dyspnoea, cyanosis and tachypnoea. Radiographic findings included an enlarged heart and pulmonary oedema, and dilated cardiomyopathy was confirmed via echocardiogram. The patient was treated for congestive heart failure because of dilated cardiomyopathy with furosemide, enalapril, pimobendan and l-carnitine. Within 24 hours of treatment, the pulmonary oedema and cyanosis had resolved. Following discharge, clinical improvement was noted by the owner and echocardiogram confirmed improved fractional shortening. Cardiomyopathy has been reported at post-mortem examination in hedgehogs, but there are no reports of ante-mortem diagnosis and treatment. Performing baseline cardiac assessment in hedgehogs is recommended, and treatment with l-carnitine and pimobendan may improve outcome, as carnitine deficiency is a possible cause of cardiomyopathy in hedgehogs. Successful emergency treatment of congestive heart failure in the hedgehog of this report may be effective for other hedgehogs presented with similar clinical signs.

  15. Congestive renal failure: the pathophysiology and treatment of renal venous hypertension.

    PubMed

    Ross, Edward A

    2012-12-01

    Longstanding experimental evidence supports the role of renal venous hypertension in causing kidney dysfunction and "congestive renal failure." A focus has been heart failure, in which the cardiorenal syndrome may partly be due to high venous pressure, rather than traditional mechanisms involving low cardiac output. Analogous diseases are intra-abdominal hypertension and renal vein thrombosis. Proposed pathophysiologic mechanisms include reduced transglomerular pressure, elevated renal interstitial pressure, myogenic and neural reflexes, baroreceptor stimulation, activation of sympathetic nervous and renin angiotensin aldosterone systems, and enhanced proinflammatory pathways. Most clinical trials have addressed the underlying condition rather than venous hypertension per se. Interpreting the effects of therapeutic interventions on renal venous congestion are therefore problematic because of such confounders as changes in left ventricular function, cardiac output, and blood pressure. Nevertheless, there is preliminary evidence from small studies of intense medical therapy or extracorporeal ultrafiltration for heart failure that there can be changes to central venous pressure that correlate inversely with renal function, independently from the cardiac index. Larger more rigorous trials are needed to definitively establish under what circumstances conventional pharmacologic or ultrafiltration goals might best be directed toward central venous pressures rather than left ventricular or cardiac output parameters. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. TCP with source traffic shaping (TCP-STS): an approach for network congestion reduction

    NASA Astrophysics Data System (ADS)

    Elaywe, Ali H.; Kamal, Ahmed E.

    2002-07-01

    The Transmission Control Protocol (TCP), provides flow control functions which are based on the window mechanism. Packet losses are detected by various mechanisms, such as timeouts and duplicate acknowledgements, and are then recovered from using different techniques. A problem that arises with the use of window based mechanisms is that the availability of a large number of credits at the source may cause a source to flood the network with back-to-back packets, which may drive the network into congestion, especially if multiple sources become active at the same time. In this paper we propose a new approach for congestion reduction. The approach works by shaping the traffic at the TCP source, such that the basic TCP flow control mechanism is still preserved, but the packet transmissions are spaced in time in order to prevent a sudden surge of traffic from overflowing the routers' buffers. Simulation results show that this technique can result in an improved network performance, in terms of reduced mean delay, delay variance, and packet dropping ratio.

  17. Cyclophilin A predicts clinical outcome in patients with congestive heart failure undergoing endomyocardial biopsy.

    PubMed

    Zuern, Christine S; Müller, Karin A L; Seizer, Peter; Geisler, Tobias; Banya, Winston; Klingel, Karin; Kandolf, Reinhard; Bauer, Axel; Gawaz, Meinrad; May, Andreas E

    2013-02-01

    Cyclophilin A (CyPA) represents a ubiquitous intracellular protein, which is secreted by inflammatory and by dying/necrotic cells. The aim of this study was to evaluate the prognostic relevance of CyPA expression in endomyocardial biopsies of consecutive patients with congestive heart failure. A total of 227 unselected patients (age 53.9 ± 15 years) with congestive heart failure undergoing endomyocardial biopsy for diagnostic reasons were enrolled. Biopsies were analysed using established histopathological and immunohistological criteria together with CyPA staining. Virus genome was studied by polymerase chain reaction. CyPA was significantly enhanced in patients with inflammatory cardiomyopathy (n = 127) as compared with patients with non-inflammatory cardiomyopathy (n = 100, P < 0.0001). During a mean follow-up of 16.3 months, 60 patients (26.4%) reached the primary endpoint, a composite of all-cause death, heart transplantation, malignant arrhythmia, and heart failure-related rehospitalization. Of all clinical (ejection fraction, New York Heart Association functional class), laboratory (brain natriuretic peptide), and immunohistological parameters (CyPA, extracellular matrix metalloproteinase inducer, CD68, CD3, major hisocompatibility complex II, and virus genome) tested, only CyPA was identified as an independent predictor for the composite endpoint [hazard ratio (HR) 2.4; 95% confidence interval (CI) 1.2-5.2; P = 0.019] as well as for all-cause death and heart transplantation alone (HR 4.7; 95% CI 1.1-19.8; P = 0.036). Subgroup analysis revealed CyPA as a predictor in patients with non-inflammatory cardiomyopathy for the composite endpoint (HR 3.0; 95% CI 1.3-6.6; P = 0.007) as well as all-cause death or heart transplantation alone (HR 6.4; 95% CI 1.4-28.1; P = 0.014). CyPA is an independent predictor of clinical outcome in patients with congestive heart failure undergoing endomyocardial biopsy.

  18. Reasoning the Causality of City Sprawl, Traffic Congestion, and Green Land Disappearance in Taiwan Using the CLD Model

    PubMed Central

    Chen, Mei-Chih; Chang, Kaowen

    2014-01-01

    Many city governments choose to supply more developable land and transportation infrastructure with the hope of attracting people and businesses to their cities. However, like those in Taiwan, major cities worldwide suffer from traffic congestion. This study applies the system thinking logic of the causal loops diagram (CLD) model in the System Dynamics (SD) approach to analyze the issue of traffic congestion and other issues related to roads and land development in Taiwan’s cities. Comparing the characteristics of development trends with yearbook data for 2002 to 2013 for all of Taiwan’s cities, this study explores the developing phenomenon of unlimited city sprawl and identifies the cause and effect relationships in the characteristics of development trends in traffic congestion, high-density population aggregation in cities, land development, and green land disappearance resulting from city sprawl. This study provides conclusions for Taiwan’s cities’ sustainability and development (S&D). When developing S&D policies, during decision making processes concerning city planning and land use management, governments should think with a holistic view of carrying capacity with the assistance of system thinking to clarify the prejudices in favor of the unlimited developing phenomena resulting from city sprawl. PMID:25383609

  19. A Case of Fulminant Hepatic Failure Secondary to Congestive Heart Failure Without Evidence of Acute Cardiac Decompensation.

    PubMed

    Wagle, Kalyan; Akinseye, Oluwaseun A; Shrestha, Prakash; Chandnani, Madhuri; Munankarmi, Raiko; Ripin, Vivian; Yee, Jimmy

    2017-04-01

    There are so far only a few reported cases of acute fulminant hepatic failure resulting from acute cardiomyopathy. This is a rare occurrence, especially in patients that do not exhibit any signs and symptoms of acute cardiac decompensation. We report a case of fulminant liver failure with nondiagnostic work up for the common causes of liver failure. This patient had concurrent history of congestive heart failure, but did not have acute decompensation. Right upper quadrant sonogram revealed hepatomegaly of 15 cm, trace amount of perihepatic ascites, pericholecystic fluid, and also thickened edematous gallbladder wall with no stones, no common bile duct stones, and no portal vein thrombosis. Echocardiogram revealed dilated left atrium and ventricle, severe mitral regurgitation, severe tricuspid regurgitation, grade 4 diastolic dysfunction, diffuse hypokinesis of left ventricle, and severely and newly reduced systolic function with an ejection fraction of 10 percent (decreased from 25 percent on last ECHO 18 months prior). Liver biopsy demonstrated marked centrilobular hepatocyte necrosis and dropout accompanied by congestion, some areas of bridging necrosis and focal confluent necrosis which was suggestive of severe congestive hepatopathy. With initiation of heart failure medications, liver function improved significantly. Copyright© South Dakota State Medical Association.

  20. Reasoning the causality of city sprawl, traffic congestion, and green land disappearance in Taiwan using the CLD model.

    PubMed

    Chen, Mei-Chih; Chang, Kaowen

    2014-11-06

    Many city governments choose to supply more developable land and transportation infrastructure with the hope of attracting people and businesses to their cities. However, like those in Taiwan, major cities worldwide suffer from traffic congestion. This study applies the system thinking logic of the causal loops diagram (CLD) model in the System Dynamics (SD) approach to analyze the issue of traffic congestion and other issues related to roads and land development in Taiwan's cities. Comparing the characteristics of development trends with yearbook data for 2002 to 2013 for all of Taiwan's cities, this study explores the developing phenomenon of unlimited city sprawl and identifies the cause and effect relationships in the characteristics of development trends in traffic congestion, high-density population aggregation in cities, land development, and green land disappearance resulting from city sprawl. This study provides conclusions for Taiwan's cities' sustainability and development (S&D). When developing S&D policies, during decision making processes concerning city planning and land use management, governments should think with a holistic view of carrying capacity with the assistance of system thinking to clarify the prejudices in favor of the unlimited developing phenomena resulting from city sprawl.

  1. Relief and Recurrence of Congestion During and After Hospitalization for Acute Heart Failure: Insights from DOSE-AHF and CARRESS-HF

    PubMed Central

    Lala, Anuradha; McNulty, Steven E.; Mentz, Robert J.; Dunlay, Shannon; Vader, Justin M.; AbouEzzeddine, Omar F.; DeVore, Adam D.; Khazanie, Prateeti; Redfield, Margaret M.; Goldsmith, Steven R.; Bart, Bradley A.; Anstrom, Kevin J.; Felker, Michael; Hernandez, Adrian F.; Stevenson, Lynne W.

    2015-01-01

    Background Congestion is the most frequent cause for hospitalization in acute decompensated heart failure (ADHF). Although decongestion is a major goal of acute therapy, it is unclear how the clinical components of congestion (e.g., peripheral edema, orthopnea) contribute to outcomes after discharge or how well decongestion is maintained. Methods and Results A post-hoc analysis was performed of 496 patients enrolled in the DOSE-AHF and CARRESS-HF trials during hospitalization with ADHF and clinical congestion. A simple “orthodema” congestion score was generated based on symptoms of orthopnea (≥2 pillows=2 points, <2 pillows=0 points) and peripheral edema (trace=0 points, moderate=1 point, severe=2 points) at baseline, discharge, and 60-day follow-up. Orthodema scores were classified as absent (score of 0), low-grade (score of 1–2), and high-grade (score of 3–4), and the association with death, rehospitalization or unscheduled medical visits through 60 days was assessed. At baseline, 65% of patients had high-grade orthodema and 35% had low-grade orthodema. At discharge, 52% patients were free from orthodema at discharge (score = 0) and these patients had lower 60-day rates of death, rehospitalization, or unscheduled visits (50%) compared to those with low-grade or high-grade orthodema (52% and 68%, respectively, p=0.038). Of the patients without orthodema at discharge, 27% relapsed to low-grade orthodema and 38% to high-grade orthodema at 60-day follow-up. Conclusions Increased severity of congestion by a simple orthodema assessment is associated with increased morbidity and mortality. Despite intent to relieve congestion, current therapy often fails to relieve orthodema during hospitalization or to prevent recurrence after discharge. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifiers: NCT00608491, NCT00577135. PMID:26041600

  2. Tunneled Pleural Catheter Placement with and without Talc Poudrage for Treatment of Pleural Effusions Due to Congestive Heart Failure.

    PubMed

    Majid, Adnan; Kheir, Fayez; Fashjian, Meghan; Chatterji, Sumit; Fernandez-Bussy, Sebastian; Ochoa, Sebastian; Cheng, George; Folch, Erik

    2016-02-01

    There is a paucity of evidence regarding the role of tunneled pleural catheters in pleural effusions caused by congestive heart failure that is refractory to medical management. The aim of this study was to assess the feasibility of tunneled pleural catheter drainage for treatment of refractory pleural effusions associated with congestive heart failure, either when used alone or with concomitant talc pleurodesis performed during thoracoscopy. This was a retrospective cohort study. We identified patients with congestive heart failure and recurrent symptomatic pleural effusions who were treated between 2005 and 2015 by placement of a tunneled pleural catheter. Patients underwent either thoracoscopy followed by talc poudrage and pleural catheter placement (group 1) or catheter insertion alone (group 2). Forthy-three catheters were inserted in 36 patients, with 15 placed in group 1 and 28 in group 2. Successful pleurodesis was seen in 80% in group 1 and 25% in group 2. The median time of catheter placement was 11.5 days in group 1 and 66 days in group 2. There was a significant decrease in hospital admissions and pleural interventions after catheter placement compared with before insertion (P < 0.05). This single-center, retrospective study demonstrated the feasibility of catheter placement used alone or with talc poudrage for the treatment of refractory pleural effusions associated with congestive heart failure. The addition of talc poudrage might increase the pleurodesis rate and reduce the days to catheter removal in highly selected patients. Prospective studies on a larger number of patients are warranted to verify the safety and efficacy of this intervention.

  3. Pulmonary Congestion and Physical Functioning in Peritoneal Dialysis Patients

    PubMed Central

    Enia, Giuseppe; Tripepi, Rocco; Panuccio, Vincenzo; Torino, Claudia; Garozzo, Maurizio; Battaglia, Giovanni Giorgio; Zoccali, Carmine

    2012-01-01

    ♦ Purpose: Decline in physical function is commonly observed in patients with kidney failure on dialysis. Whether lung congestion, a predictable consequence of cardiomyopathy and fluid overload, may contribute to the low physical functioning of these patients has not been investigated. ♦ Methods: In 51 peritoneal dialysis (PD) patients, we investigated the cross-sectional association between the physical functioning scale of the Kidney Disease Quality of Life Short Form (KDQOL-SF: Rand Corporation, Santa Monica, CA, USA) and an ultrasonographic measure of lung water recently validated in dialysis patients. The relationship between physical functioning and lung water was also analyzed taking into account the severity of dyspnea measured using the New York Heart Association (NYHA) classification currently used to grade the severity of heart failure. ♦ Results: Evidence of moderate-to-severe lung congestion was evident in 20 patients, and this alteration was asymptomatic (that is, NHYHA class I) in 11 patients (55%). On univariate analysis, physical functioning was inversely associated with lung water (r = -0.48, p < 0.001), age (r = -0.44, p = 0.001), previous cardiovascular events (r = -0.46, p = 0.001), and fibrinogen (r = -0.34, p = 0.02). Physical functioning was directly associated with blood pressure, the strongest association being with diastolic blood pressure (r = 0.38, p = 0.006). The NYHA class correlated inversely with physical functioning (r = -0.51, p < 0.001). In multiple regression analysis, only lung water and fibrinogen remained independent correlates of physical functioning. The NYHA class failed to maintain its independent association. ♦ Conclusions: This cross-sectional study supports the hypothesis that symptomatic and asymptomatic lung congestion is a relevant factor in the poor physical functioning of patients on PD. PMID:22942271

  4. Transmission dispatch and congestion management in open market systems

    NASA Astrophysics Data System (ADS)

    Fang, Risheng

    This thesis is located in the domain of electricity supply industry restructuring. It deals with emerging issues, whose understanding is essential to advancing knowledge of open access transmission theory and proceeds to develop approaches for solving the transmission dispatch and congestion management problem. An overview of current trends and experiences in utility restructuring and the main models for restructuring, as well as the classifications of system operators, is first presented. A fully unbundled competitive electricity market model, called the bilateral/multilateral trades model, is then developed. A survey of current research in transmission dispatch and congestion management is included with discussion of transmission capacity and ancillary services. A methodology for the power dispatch problem in a structure dominated by bilateral and multilateral transmission contracts is presented. Group structures are mathematically formulated and explored and three basic types of curtailment strategies proposed for use by market participants. A more complex model is then developed, which takes into account the co-existence of bilateral and multilateral contracts with pool type dynamic supplies and demands based on bids and market clearing prices. An integrated dispatch strategy to reconcile all three types of transactions (bilateral, multilateral and pool) is then developed. Prioritization of electricity transactions and related curtailment strategies are explored and a mechanism for coordination between market participants to achieve additional economic advantages is described. A theory of security based rescheduling is presented in order to investigate the security-related aspects of operation in an unbundled and deregulated system. The impact of post-contingency corrective capability on optimal rescheduling results has been identified and the advantage of incorporating post-contingency corrective rescheduling into the objective function demonstrated. Finally

  5. Nitrendipine binding in congestive heart failure due to myocardial infarction

    SciTech Connect

    Dixon, I.M.; Lee, S.L.; Dhalla, N.S. )

    1990-03-01

    Depressed cardiac pump function is the hallmark of congestive heart failure, and it is suspected that decreased influx of Ca2+ into the cardiac cell is responsible for depressed contractile function. Since Ca2+ channels in the sarcolemmal membrane are considered to be an important route for the entry of Ca2+, we examined the status of Ca2+ receptors/channels in failing rat hearts after myocardial infarction of the left ventricular free wall. For this purpose, the left coronary artery was ligated and hearts were examined 4, 8, and 16 weeks later; sham-operated animals served as controls. Hemodynamic assessment revealed decreased total mechanical energy (left ventricular systolic pressure x heart rate), increased left ventricular diastolic pressure, and decreased positive and negative dP/dt in experimental animals at 4, 8, and 16 weeks. Although accumulation of ascites in the abdominal cavity was evident at 4 weeks, other clinical signs of congestive heart failure in experimental rats were evident from the presence of lung congestion and cardiac dilatation at 8 and 16 weeks after induction of myocardial infarction. The density of Ca2+ receptors/channels in crude membranes, as assessed by (3H)nitrendipine binding assay, was found to be decreased in the uninfarcted experimental left ventricle at 8 and 16 weeks; however, no change in the affinity of nitrendipine was evident. A similar depression in the specific binding of another dihydropyridine compound, (3H)PN200-110, was also evident in failing hearts. Brain and skeletal muscle crude membrane preparations, unlike those of the right ventricle and liver, revealed a decrease in Ca2+ receptors/channels density in experimental animals at 16 weeks.

  6. Study on the propagation and dissipation of inland ship congestion under different control strategies

    NASA Astrophysics Data System (ADS)

    Chen, Yanyi; Wu, Hongyu; Wen, Zhe

    2017-05-01

    Inland waterway transportation is an important part of the comprehensive transportation system of sustainable development, and it is also a way of transportation which is restricted by natural conditions greatly. In recent years, the problems of insufficient traffic capacity of The Three Gorges become prominent due to the increasing in the number of ships. And the ship's detention caused by gale, frog, accident and one-way traffic in dry season has occurred, which not only increased the pressure of the navigable waterway but also seriously affected the safety of shipping. Based on the different types of ships, the Arena software was used to simulate the ship traffic flow. The paper analyzed the traffic congestion propagation and dissipation rule of the ship under different navigation control methods, and provided decision reference for the navigation management department to formulate the relevant navigation control strategy.

  7. Enhanced TCP Congestion Control Realizing Higher Throughput and Inter-Session Fairness in Multihop Wireless Networks

    NASA Astrophysics Data System (ADS)

    Yamamoto, Takehito; Tode, Hideki; Murakami, Koso

    It is known that TCP data transfer in a wireless multihop network experiences a degradation in inter-connection fairness and throughput. This is because TCP is designed for use in wired networks, and the wireless multihop network has characteristics of sharing of the medium resources among nodes, which wired networks do not have. In particular, in wireless multihop networks where wireless nodes widely exist, hidden/exposed terminal problems are caused even if an RTS/CTS handshake is used. In this paper, two methods are proposed to improve fairness and throughput, without any feedback information from the intermediate nodes or cross-layer information. One method restricts the transfer period, while the other restrains the TCP congestion window. We evaluated these methods using computer simulations.

  8. Effect of Cardiac Resynchronization Therapy on Inflammation in Congestive Heart Failure: A Review.

    PubMed

    Lappegård, K T; Bjørnstad, H; Mollnes, T E; Hovland, A

    2015-09-01

    Congestive heart failure is associated with increased levels of several inflammatory mediators, and animal studies have shown that infusion of a number of cytokines can induce heart failure. However, several drugs with proven efficacy in heart failure have failed to affect inflammatory mediators, and anti-inflammatory therapy in heart failure patients has thus far been disappointing. Hence, to what extent heart failure is caused by or responsible for the increased inflammatory burden in the patient is still unclear. Over the past couple of decades, resynchronization therapy with a biventricular pacemaker has emerged as an effective treatment in a subset of heart failure patients, reducing both morbidity and mortality. Such treatment has also been shown to affect the inflammation associated with heart failure. In this study, we review recent data on the association between heart failure and inflammation, and in particular how resynchronization therapy can affect the inflammatory process.

  9. Anesthesia and congestive heart failure: pathology, medical, and surgical management.

    PubMed

    Armstrong, Christopher S; Hoover, Jason M; Fox, Charles J; Field, Aaron M; Richards, Todd A; Islam, Sameer R; Kaye, Alan D

    2006-06-01

    Congestive heart failure (CHF) is increasingly being recognized as a health problem in the United States. It is estimated that the lifetime risk for CHF is 1 in 5. The clinical anesthesiologist can expect to see several cases involving patients suffering from CHF. Because of the danger associated with surgery in a patient with CHF, a thorough knowledge of the disorder and the potential effects on the delivery of anesthetics must be considered. In addition, knowledge of the disease process and its manifestations is required for smooth guidance of the patient through the perioperative period. The understanding of current pharmacotherapies, surgical procedures and their implications related to interactions with anesthetics are all discussed.

  10. Congestive Heart Failure home monitoring pilot study in urban Denver.

    PubMed

    Bakhshi, Saba; Li, Xin; Semenov, Nikolay; Apodaca-Madrid, Jesús; Mahoor, Mohammad H; Newman, Kimberly E; Long, Carlin S; Neuman, Christine

    2011-01-01

    With a growing number of low-income patients developing Congestive Heart Failure in urban Denver, accessible and affordable solutions are needed to provide home management options. A multidisciplinary team evaluated currently available options for telemonitoring and developed a solution for an initial pilot study. This system is currently used in the Denver Metro area (Colorado) for 44 CHF patients. Preliminary results show this approach is effective and has reduced the patients' average length of stay at the hospital compared to historical data and control patients who do not use a remote monitoring system.

  11. Effect of Congestion Costs on Shortest Paths Through Complex Networks

    NASA Astrophysics Data System (ADS)

    Ashton, Douglas J.; Jarrett, Timothy C.; Johnson, Neil F.

    2005-02-01

    We analyze analytically the effect of congestion costs within a physically relevant, yet exactly solvable, network model featuring central hubs. These costs lead to a competition between centralized and decentralized transport pathways. In stark contrast to conventional no-cost networks, there now exists an optimal number of connections to the central hub in order to minimize the shortest path. Our results shed light on an open problem in biology, informatics, and sociology, concerning the extent to which decentralized versus centralized design benefits real-world complex networks.

  12. Cerebral Venous Congestion as Indication for Thrombolytic Treatment

    SciTech Connect

    Tsai, Fong Y. Kostanian, Varoujan; Rivera, Monica; Lee, Kwo-Whie; Chen, Clayton C.; Nguyen, Thong H.

    2007-07-15

    Purpose. To carry out a retrospective analysis of patients with acute dural sinus thrombosis, and the role of cerebral venous congestion in patient management. Methods. Twenty-five patients were identified with the clinical and imaging diagnosis of acute dural sinus thrombosis. The imaging diagnosis was by magnetic resonance (MR) and/or computed tomography (CT) venography. There was a female predominance with a female to male ratio of 1.5 to 1 (16 women, 9 men). The age range was from 19 to 64 years old with an average age of 37 years. The first 10 patients, who ranged in age from 21 to 64 years old (average 37 years), received only anticoagulation therapy with heparin and warfarin for periods ranging from 5 days to 2 months. The remaining 15 patients ranged in age from 19 to 57 years old (average 38 years). They either underwent subsequent thrombectomy after a trial of anticoagulation therapy, or went straight to thrombectomy. These latter 15 patients had initial evidence of cerebral venous congestion, either clinically by severe or worsening symptoms despite anticoagulation therapy, or on initial or subsequent CT or MR imaging. In our experience, the cerebral venous congestion imaging findings included intracranial hemorrhage, a hematoma, or edema. The thrombolytic treatment technique consisted of the advancement of a 6 Fr guiding catheter to the jugular bulb or sigmoid sinus from a transfemoral approach. A microcatheter was then advanced to the proximal portion of the thrombus and then either tissue plasminogen activator (tPA) or urokinase was injected to prevent clot propagation. A balloon catheter was used to perform thrombectomy since the thrombolytic agents can be injected via the inner lumen with an inflated balloon. The inflated balloon helped to keep the venous flow from washing out the thrombolytic agent, thus facilitating the agent's effect. Results. The first 10 patients received only anticoagulation therapy with heparin and warfarin for periods

  13. Germany's Disease Management Program: Improving Outcomes in Congestive Heart Failure

    PubMed Central

    Kottmair, Stefan; Frye, Christian; Ziegenhagen, Dieter J.

    2005-01-01

    Hospital admissions among patients with congestive heart failure (CHF) are a major contributor to health care costs. A comprehensive disease management program for CHF was developed for private and statutory health insurance companies in order to improve health outcomes and reduce rehospitalization rates and costs. The program comprises care calls, written training material, telemetric monitoring, and health reports. Currently, 909 members from six insurance companies are enrolled. Routine evaluation, based on medical data warehouse software, demonstrates benefits in terms of improved health outcomes and processes of care. Economical evaluation of claims data indicates significant cost savings in a pre/post study design. PMID:17288080

  14. Effect of congestion costs on shortest paths through complex networks.

    PubMed

    Ashton, Douglas J; Jarrett, Timothy C; Johnson, Neil F

    2005-02-11

    We analyze analytically the effect of congestion costs within a physically relevant, yet exactly solvable, network model featuring central hubs. These costs lead to a competition between centralized and decentralized transport pathways. In stark contrast to conventional no-cost networks, there now exists an optimal number of connections to the central hub in order to minimize the shortest path. Our results shed light on an open problem in biology, informatics, and sociology, concerning the extent to which decentralized versus centralized design benefits real-world complex networks.

  15. Germany's disease management program: improving outcomes in congestive heart failure.

    PubMed

    Kottmair, Stefan; Frye, Christian; Ziegenhagen, Dieter J

    2005-01-01

    Hospital admissions among patients with congestive heart failure (CHF) are a major contributor to health care costs. A comprehensive disease management program for CHF was developed for private and statutory health insurance companies in order to improve health outcomes and reduce rehospitalization rates and costs. The program comprises care calls, written training material, telemetric monitoring, and health reports. Currently, 909 members from six insurance companies are enrolled. Routine evaluation, based on medical data warehouse software, demonstrates benefits in terms of improved health outcomes and processes of care. Economical evaluation of claims data indicates significant cost savings in a pre/post study design.

  16. Congestive myelopathy (Foix-Alajouanine Syndrome) due to intradural arteriovenous fistula of the filum terminale fed by anterior spinal artery: Case report and review of literature.

    PubMed

    Krishnan, Prasad; Banerjee, Tapas Kumar; Saha, Manash

    2013-07-01

    Spinal arteriovenous fistulas are rare entities. They often present with congestive myelopathy but are infrequently diagnosed as the cause of the patients' symptoms. Only one such case has been described previously in Indian literature. We describe one such case who presented to us after a gap of 3 years since symptom onset and following a failed laminectomy where the cause was later diagnosed to be an intradural fistula in the filum terminale fed by the anterior spinal artery and review the available literature.

  17. Experimental Verification of H∞ Congestion Controllers for TCP/AQM Networks

    NASA Astrophysics Data System (ADS)

    Naito, Hiroyuki; Azuma, Takehito; Nishimura, Akihiko; Fujita, Masayuki

    The purpose of this paper is to design a congestion controller for TCP/AQM networks based on the H∞ control theory, and validate the effectiveness of the designed H∞ congestion controller via a testbed which is the small-scale network for verification of the designed H∞ congestion controller. Firstly, a nonlinear and the linearized model of TCP/AQM networks are introduced, and control objectives are described. The H∞ congestion controller is designed by solving the mixed sensitivity problem for the linearized model. In order to verify the designed H∞ congestion controller, we show simulation results using SIMULINK and ns-2 simulator, and compare the congestion controller via PI control with the designed H∞ congestion controller. Finally, we develop a testbed for verification of the effectiveness of the designed H∞ congestion controller which is implemented to the testbed by improving Linux kernel and carry out an experiment. As experimental results using the developed testbed, we show the queue size in the router, where the designed H∞ congestion controller is implemented, and confirm that the control objectives are achieved.

  18. Improving UDP/IP Transmission Without Increasing Congestion

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott

    2006-01-01

    Datagram Retransmission (DGR) is a computer program that, within certain limits, ensures the reception of each datagram transmitted under the User Datagram Protocol/Internet Protocol. [User Datagram Protocol (UDP) is considered unreliable because it does not involve a reliability-ensuring connection-initiation dialogue between sender and receiver. UDP is well suited to issuing of many small messages to many different receivers.] Unlike prior software for ensuring reception of UDP datagrams, DGR does not contribute to network congestion by retransmitting data more frequently as an ever-increasing number of messages and acknowledgements is lost. Instead, DGR does just the opposite: DGR includes an adaptive timeout-interval- computing component that provides maximum opportunity for reception of acknowledgements, minimizing retransmission. By monitoring changes in the rate at which message-transmission transactions are completed, DGR detects changes in the level of congestion and responds by imposing varying degrees of delay on the transmission of new messages. In addition, DGR maximizes throughput by not waiting for acknowledgement of a message before sending the next message. All DGR communication is asynchronous, to maximize efficient utilization of network connections. DGR manages multiple concurrent datagram transmission and acknowledgement conversations.

  19. Nonlinear dynamics of congestive heart failure (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Bernjak, Alan; Clarkson, Peter B. M.; McClintock, Peter V. E.; Stefanovska, Aneta

    2005-05-01

    Preliminary results are reported from a research project analysing congestive heart failure in terms a stochastic coupled-oscillator model of the cardiovascular system. Measurements of blood flow by laser Doppler flowmetry (LDF) have been processed by use of the wavelet transform to separate its oscillatory components, which number at least five. Particular attention was concentrated on the frequency content near 0.01 Hz, which is known to be associated with endothelial function. The LDF was carried out in conjunction with iontophoretically administered acetylcholine (ACh) and sodium nitroprusside (SNP) in order to evaluate endothelial reactivity. Measurements were made on 17 congestive heart failure (CHF) patients (a) on first diagnosis, and (b) again several weeks later after their treatment with a β-blocker had been stabilised. The results of these two sets of measurements are being compared with each other, and with data from an age and sex-matched group of healthy controls. It is confirmed that endothelial reactivity is reduced in CHF patients, as compared to healthy controls, and it is found that one effect of the Beta-blocker is to ameliorate the loss of endothelial function in CHF. The implications of these results are discussed.

  20. The impact of congestion charging on social capital.

    PubMed

    Munford, Luke A

    2017-03-01

    We analyse a new data set to examine how congestion charging policies affect an individual's investment social capital. We exploit a (quasi-) natural experiment - the implementation of the Western Extension Zone (WEZ) to the London Congestion Charging zone in 2007. We measure investment in social capital by using the frequency of visits to friends and family before and after the implementation of the WEZ. Using longitudinal data collected in January and November 2007 made available by Transport for London, we perform difference-in-difference analysis, using both OLS and interval regression, with the treatment group defined as those who used a car to make visits pre-WEZ. We observe large and statistically significant reductions in visits as a result of the WEZ, with, for example, a reduction of around 20 visits a year to friends. The effect of the WEZ on the number of visits to act as an informal carer is much larger, with reductions of around 100 visits a year. Given that the changes occurred in such a small time frame (10 months), we conclude that the WEZ is likely to be the main driver of these reductions.

  1. A minimal model for congestion phenomena on complex networks

    NASA Astrophysics Data System (ADS)

    DeMartino, Daniele; Dall'Asta, Luca; Bianconi, Ginestra; Marsili, Matteo

    2009-08-01

    We study a minimal model of traffic flows in complex networks, simple enough for getting analytical results, but with a very rich phenomenology, presenting continuous, discontinuous as well as hybrid phase transitions between a free-flow phase and a congested phase, critical points and different behaviors of scaling with the system size. It consists of random walkers on a queuing network with one-range repulsion, where particles can be destroyed only if they can move. We focus on the dependence on the topology as well as on the level of traffic control. We are able to obtain transition curves and phase diagrams at an analytical level for the ensemble of uncorrelated networks and numerically for single instances. We find that traffic control improves global performance, enlarging the free-flow region in parameter space only in heterogeneous networks. Traffic control introduces non-linear effects and, beyond a critical strength, may trigger the appearance of a congested phase in a discontinuous manner. The model also reproduces the crossover in the scaling of traffic fluctuations empirically observed in the Internet, and moreover, a conserved version can reproduce qualitatively some stylized facts of traffic in transportation networks.

  2. Cascading Failures in Congested Scale-Free Networks

    NASA Astrophysics Data System (ADS)

    Zheng, Jian-Feng; Yang, Ling-Xiao; Gao, Zi-You; Fu, Bai-Bai

    In this work, we study the effect of congestion on the behavior of cascading failures in scale-free networks, where a capacity is assigned on each node (controlled by a tolerance parameter α), and traffic flows are governed by user equilibrium instead of going along the shortest paths. The effect of congestion can be described by link cost function, which denotes the time needed to travel along the link. Here we focus on studying the effect of link's practical capacity, which is a parameter in link cost function. Two different kinds of link's practical capacity are investigated, i.e. uniform case and nonuniform case. In the uniform case, each link has the same value of practical capacity. While in the nonuniform case, we assume that link's practical capacity and degrees of the link's endpoints are correlated (controlled by parameter θ, which governs the heterogeneity of link's practical capacity). Simulation results show that, in the uniform case, scale-free networks are more prone to cascading failures when increasing the value of link's practical capacity. In the nonuniform case, cascading failures in scale-free networks are very sensitive to α when θ > 0; while θ < 0, scale-free networks may suffer from serious cascading failures, regardless of α.

  3. Adaptive mechanism-based congestion control for networked systems

    NASA Astrophysics Data System (ADS)

    Liu, Zhi; Zhang, Yun; Chen, C. L. Philip

    2013-03-01

    In order to assure the communication quality in network systems with heavy traffic and limited bandwidth, a new ATRED (adaptive thresholds random early detection) congestion control algorithm is proposed for the congestion avoidance and resource management of network systems. Different to the traditional AQM (active queue management) algorithms, the control parameters of ATRED are not configured statically, but dynamically adjusted by the adaptive mechanism. By integrating with the adaptive strategy, ATRED alleviates the tuning difficulty of RED (random early detection) and shows a better control on the queue management, and achieve a more robust performance than RED under varying network conditions. Furthermore, a dynamic transmission control protocol-AQM control system using ATRED controller is introduced for the systematic analysis. It is proved that the stability of the network system can be guaranteed when the adaptive mechanism is finely designed. Simulation studies show the proposed ATRED algorithm achieves a good performance in varying network environments, which is superior to the RED and Gentle-RED algorithm, and providing more reliable service under varying network conditions.

  4. Modeling and simulating for congestion pedestrian evacuation with panic

    NASA Astrophysics Data System (ADS)

    Wang, Jinhuan; Zhang, Lei; Shi, Qiongyu; Yang, Peng; Hu, Xiaoming

    2015-06-01

    A new multi-agent based congestion evacuation model incorporating panic behavior is proposed in this paper for simulating pedestrian evacuation in public places such as a stadium. Different from the existing results, pedestrians in this model are divided into four classes and each pedestrian's status can be either normal, being overtaken, or casualty. The direction of action for each individual is affected by competitive ability, distance to the exits as well as number and density of occupants within the view field of the agent. Our simulations exhibit that during the evacuation process: (1) The agents gather in front of the exits spontaneously and present arched shapes close to the exits. (2) Under the panic state the agents cohere closely and almost do not change the target exit. So other alternative exits are ignored. (3) For the case without obstacle, the casualties under panic increase greatly. But if there are obstacles (chairs), the congestion can be alleviated. Thus the casualties are reduced. (4) If certain exit is partly clogged, the evacuation becomes more efficient when adding a virtual leader. The overall simulation results show that the proposed model can reproduce the real evacuation process in a stadium quite well.

  5. Transportation network policy modeling for congestion and pollution control: A variational inequality approach

    NASA Astrophysics Data System (ADS)

    Ramanujam, Padma

    1999-08-01

    Public concern over the state of the environment has grown over the past decade. All indications are that this concern will continue to influence policy making into the foreseeable future. Road transport is seen as the major contributor to environmental degradation. Transportation planners around the world face the question: cleaner air and/or faster commutes? While individual vehicles can be made more environmentally friendly, the sheer scale of growth in world-wide vehicle numbers is projected to cause significant environmental degradation in the longer run, and in the absence of newer and stricter polices. It is a challenge for governments to find policies that ensure congestion-free metropolitan areas while guaranteeing both critical environmental quality levels and a sufficient infrastructure access to all groups involved. The objective of the dissertation is to provide a mathematical framework to study transportation policy models for the purpose of controlling congestion and pollution. Towards this objective. a series of transportation policy models are developed to study travel behavior and to quantity the reductions in congestion and automobile emissions. The dissertation begins with a brief historical overview of some of the pioneering works in urban transportation economics and later presents the theoretical foundation for the transportation policy models developed. The dissertation introduces single modal and multimodal transportation network policy models that accomplish road pricing with the imposition of goal targets on link loads. as well as, integrated traffic equilibrium models with marketable mobile emission permits. Furthermore, equilibrium conditions are derived for each model, and both qualitative analysis and computational procedures are studied. Finally, the dissertation concludes with a comparative study of the relationship between regulatory pricing models and marketable emission permit transportation models and a discussion on key factors

  6. Left ventricular filling after long-term angiotensin converting enzyme inhibition in congestive heart failure.

    PubMed

    Baur, L H; Schipperheyn, J J; Cats, V M; van der Wall, E E; Baan, J; van Dijk, A D; Bruschke, A V

    1992-11-01

    As a rule, left ventricular relaxation is impaired in patients with coronary artery disease and congestive heart failure. In addition, the passive elastic properties in early and late diastole change when the ventricle dilates. Diastolic properties of the left ventricle were studied in 11 patients with congestive heart failure class II-IV (NYHA) before and 3 months after 10-20 mg enalapril was added to their regimen of salt restriction, a diuretic and occasionally digitalis. Haemodynamic studies were performed using radionuclide angiography and simultaneous pressure-volume measurements. Systemic vascular resistance decreased from 1479 to 1182 dynes.s.-1 cm-5 (P < 0.05) and left ventricular end-diastolic pressure from 19.2 to 15.9 mmHg (P < 0.05). Left ventricular end-diastolic volume index decreased from 130 +/- 22 to 81 +/- 22 ml (P < 0.01). Indices of early diastolic relaxation, such as peak filling rate (1.43 +/- 0.46 to 1.49 +/- 0.84 EDV/s), time to peak filling rate (460 +/- 70 to 490 +/- 70 ms), peak negative dP/dt (-903 +/- 190 to -891 +/- 190 mmHg/s) and tau, the time constant of isovolumic pressure decay (58.7 +/- 14.4 to 48.4 +/- 15.2 ms) did not change significantly. In nine patients pressure-volume loops shifted to the left in all patients but one due to reduction in end-systolic and end-diastolic volume. The steepness of the diastolic part of the pressure-volume relationship increased, indicating an increase in chamber stiffness. The stiffness constant increased about 25% towards a more normal value. The alteration in stiffness seemed to be mainly due to the change of the geometry of the ventricle and not to a major change in the visco-elastic properties of the ventricular wall. In conclusion, regression of remodelling induced by enalapril does not change diastolic function parameters in patients with chronic congestive heart failure beyond the changes caused by regression of ventricular dilation.

  7. A Bayesian ridge regression analysis of congestion's impact on urban expressway safety.

    PubMed

    Shi, Qi; Abdel-Aty, Mohamed; Lee, Jaeyoung

    2016-03-01

    With the rapid growth of traffic in urban areas, concerns about congestion and traffic safety have been heightened. This study leveraged both Automatic Vehicle Identification (AVI) system and Microwave Vehicle Detection System (MVDS) installed on an expressway in Central Florida to explore how congestion impacts the crash occurrence in urban areas. Multiple congestion measures from the two systems were developed. To ensure more precise estimates of the congestion's effects, the traffic data were aggregated into peak and non-peak hours. Multicollinearity among traffic parameters was examined. The results showed the presence of multicollinearity especially during peak hours. As a response, ridge regression was introduced to cope with this issue. Poisson models with uncorrelated random effects, correlated random effects, and both correlated random effects and random parameters were constructed within the Bayesian framework. It was proven that correlated random effects could significantly enhance model performance. The random parameters model has similar goodness-of-fit compared with the model with only correlated random effects. However, by accounting for the unobserved heterogeneity, more variables were found to be significantly related to crash frequency. The models indicated that congestion increased crash frequency during peak hours while during non-peak hours it was not a major crash contributing factor. Using the random parameter model, the three congestion measures were compared. It was found that all congestion indicators had similar effects while Congestion Index (CI) derived from MVDS data was a better congestion indicator for safety analysis. Also, analyses showed that the segments with higher congestion intensity could not only increase property damage only (PDO) crashes, but also more severe crashes. In addition, the issues regarding the necessity to incorporate specific congestion indicator for congestion's effects on safety and to take care of the

  8. Venous Congestive Myelopathy due to Chronic Inferior Vena Cava Thrombosis Treated with Endovascular Stenting: Case Report and Review of the Literature

    PubMed Central

    Carvalho, Diego Z.; Hughes, Joshua D.; Liebo, Greta B.; Bendel, Emily C.; Bjarnason, Haraldur; Klaas, James P.

    2015-01-01

    Objective Impaired inferior vena cava (IVC) outflow can lead to collateralization of blood to the valveless epidural venous plexus, causing epidural venous engorgement and venous congestion. Herein we describe a case of chronic IVC thrombosis presenting as venous congestive myelopathy treated with angioplasty and endovascular stenting. The pathophysiological mechanisms of cord injury are hypothesized, and IVC stenting application is evaluated. Methods Case report and review of the literature. Results IVC outflow obstruction has only rarely been associated with neurologic dysfunction, with reports of lumbosacral nerve root compression in the cases of IVC agenesis, compression, or occlusion. Although endovascular angioplasty with stenting is emerging as a leading treatment option for chronic IVC thrombosis, its use to treat neurologic complications is limited to one case report for intractable sciatica. Our case is the first description of IVC thrombosis presenting with venous congestive myelopathy, and treated successfully with IVC stenting. Conclusion Venous congestive myelopathy should be seen as a broader clinical condition, including not only typical dural arteriovenous fistulas, but also disorders of venous outflow. Therefore, identifying a rare, but potentially treatable, etiology is important to avoid permanent neurologic deficits. IVC stenting is proposed as a novel and effective treatment approach. PMID:25825633

  9. Congestive heart failure as a determinant of postoperative delirium.

    PubMed

    Parente, Daniela; Luís, Clara; Veiga, Dalila; Silva, Hugo; Abelha, Fernando

    2013-09-01

    Postoperative delirium (POD) is a frequent post-surgical complication that is associated with increased mortality and poor patient outcomes. POD is a complex disorder with multiple risk factors such as pre-existing patient comorbidities and perioperative complications. The aim of this study was to evaluate the incidence of POD and to identify risk factors for the development of POD in a post-anesthesia care unit (PACU). We enrolled 97 adult patients admitted to a PACU over a five-day period (start date September 6, 2010). Patient demographics and intraoperative and postoperative data were collected. Patients were followed for the development of delirium using the Intensive Care Delirium Screening Checklist. Descriptive analyses of variables were used to summarize data, and the Mann-Whitney U test was used to compare continuous variables; the chi-square or Fisher's exact test was used for comparisons. Univariate analysis was performed using simple binary logistic regression with odds ratios (OR) and 95% confidence intervals (95% CI). The significance level for multiple comparisons was controlled by applying the Bonferroni correction for multiple comparisons and variables were deemed significant if p≤0.0025. Six percent of patients developed POD. These patients were older and more likely to have higher American Society of Anesthesiologists (ASA) physical status (83 vs. 22% with ASA III/IV, p=0.004) as well as a higher frequency of congestive heart failure (50 vs. 3%, p=0.003) and a higher Revised Cardiac Risk Index (RCRI) score (33 vs. 6% with RCRI ≥2, p=0.039). The duration of anesthesia for patients with POD was also longer and they received a greater volume of crystalloids, colloids, and erythrocytes during surgery. Congestive heart disease was an independent risk factor for POD (OR 29.3, 95% CI 4.1-210.6; p<0.001). In addition, patients who developed POD had higher in-hospital mortality and longer PACU and hospital stays. Patients who developed POD had longer

  10. Bringing the world to a standstill: an investigation into the effects of a Novarupta scale volcanic eruption on today's aviation industry

    NASA Astrophysics Data System (ADS)

    Welchman, R. A.

    2010-12-01

    Novarupta erupted in Alaska on 6th June 1912 and was the biggest of the 21st century. It erupted for 60 hours and sent an ash cloud over 32,000m into the air. People were stranded for several days, houses destroyed, villages abandoned and food supplies disrupted for a long period after the eruption. Ash was recorded to have travelled over 9,500km away in Africa, demonstrating potentially global impacts. The eruption occurred when Alaska had very little aviation industry, today however the airspace above Alaska is one of the busiest in the world. The eruption in Iceland in 2010 which disrupted the European airspace for several weeks and closed it completely for five days, brought to light just how disruptive a volcanic eruption can be, even in countries where volcanic activity is not considered a hazard. It was an expensive event for the aviation industry and caused much disruption. Simulations of a Katmai scale eruption were run in the ‘present-day’, using the PUFF ash fall model. Simulations were run for one week from the start the eruption. A ‘worst-case’ scenario is presented based on data from 2005-2009. It is a hypothetical eruption started on 17th January 2005 and it shows that ash is likely to cause havoc in North America, Europe and parts of Asia. At least 43 airports on average would be severely affected each day of the simulation, leading to several of the major air routes being affected. Where financial data is available, an estimated cost of this event is presented. A 500 hr simulation is presented to demonstrate the possible global effects that could occur within three weeks of an eruption. It shows ash being transported across the equator at high altitudes to the southern hemisphere in Asia as well as the whole of the northern hemisphere being engulfed. The complex implications an eruption like this would have on national and international infrastructures is presented. The results could aid further scientific studies, governmental bodies and

  11. Congestion at Card and Book Catalogs--A Queuing-Theory Approach

    ERIC Educational Resources Information Center

    Bookstein, Abraham

    1972-01-01

    This paper attempts to analyze the problem of congestion, using a mathematical model shown to be of value in other similar applications. Three criteria of congestion are considered, and it is found that the conclusion one can draw is sensitive to which of these criteria is paramount. (8 references) (Author/NH)

  12. 76 FR 75875 - Plan for Conduct of 2012 Electric Transmission Congestion Study

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-05

    ... for Conduct of 2012 Electric Transmission Congestion Study AGENCY: Office of Electricity Delivery and... regional workshops and request for written comments in connection with the preparation of a study of...://energy.gov/oe/congestion-study-2012 . ] Issued in Washington, DC on November 29, 2011. Patricia A...

  13. Traffic Congestion on a University Campus: A Consideration of Unconventional Remedies to Nontraditional Transportation Patterns

    ERIC Educational Resources Information Center

    Kaplan, Dave; Clapper, Thomas

    2007-01-01

    U.S. transportation data suggest that the number of vehicle miles traveled has far surpassed new capacity, resulting in increased traffic congestion in many communities throughout the country. This article reports on traffic congestion around a university campus located within a small town. The mix of trip purposes varies considerably in this…

  14. Traffic Congestion on a University Campus: A Consideration of Unconventional Remedies to Nontraditional Transportation Patterns

    ERIC Educational Resources Information Center

    Kaplan, Dave; Clapper, Thomas

    2007-01-01

    U.S. transportation data suggest that the number of vehicle miles traveled has far surpassed new capacity, resulting in increased traffic congestion in many communities throughout the country. This article reports on traffic congestion around a university campus located within a small town. The mix of trip purposes varies considerably in this…

  15. Congestion at Card and Book Catalogs--A Queuing-Theory Approach

    ERIC Educational Resources Information Center

    Bookstein, Abraham

    1972-01-01

    This paper attempts to analyze the problem of congestion, using a mathematical model shown to be of value in other similar applications. Three criteria of congestion are considered, and it is found that the conclusion one can draw is sensitive to which of these criteria is paramount. (8 references) (Author/NH)

  16. Common Cold in Babies: Symptoms and Causes

    MedlinePlus

    Common cold in babies Symptoms and causes By Mayo Clinic Staff The first indication of the common cold in a baby is often: A congested or ... or green Other signs and symptoms of a common cold in a baby may include: Fever Sneezing Coughing ...

  17. Problems of rapid digitalization in severe congestive heart failure.

    PubMed

    Haustein, K O; Assmann, I; Fiehring, H

    1980-02-01

    The pharmacodynamic effects (changes of systolic time intervals, STI, reaction of pulmonary arterial pressure) of digitoxin were studied in 7 patients with severe congestive heart failure in comparison with the corresponding plasma level. STI indicated glycoside-dependent changes, i.e. shortening of LVETc and QS2c and normalization of prolonged PEPc, while ICT shortening was less observed. In 2 patients with cor pulmonale a pulmonary oedema occurred accompanied with prolonged LVETc. During the early period of glycoside-dependent recompensation no significant correlation between STI shortening and glycoside plasma level was observed. Because of the retarded normalization of the haemodynamics of the pulmonary circulation and because of possible side-effects, rapid digitalization has to be reconsidered.

  18. Complexity in congestive heart failure: A time-frequency approach

    NASA Astrophysics Data System (ADS)

    Banerjee, Santo; Palit, Sanjay K.; Mukherjee, Sayan; Ariffin, MRK; Rondoni, Lamberto

    2016-03-01

    Reconstruction of phase space is an effective method to quantify the dynamics of a signal or a time series. Various phase space reconstruction techniques have been investigated. However, there are some issues on the optimal reconstructions and the best possible choice of the reconstruction parameters. This research introduces the idea of gradient cross recurrence (GCR) and mean gradient cross recurrence density which shows that reconstructions in time frequency domain preserve more information about the dynamics than the optimal reconstructions in time domain. This analysis is further extended to ECG signals of normal and congestive heart failure patients. By using another newly introduced measure—gradient cross recurrence period density entropy, two classes of aforesaid ECG signals can be classified with a proper threshold. This analysis can be applied to quantifying and distinguishing biomedical and other nonlinear signals.

  19. Weighted congestion coefficient feedback in intelligent transportation systems

    NASA Astrophysics Data System (ADS)

    Dong, Chuan-Fei; Ma, Xu; Wang, Bing-Hong

    2010-03-01

    In traffic systems, a reasonable information feedback can improve road capacity. In this Letter, we study dynamics of traffic flow with real-time information. And the influence of a feedback strategy named Weighted Congestion Coefficient Feedback Strategy (WCCFS) is introduced, based on a two-route scenario in which dynamic information can be generated and displayed on the board to guide road users to make a choice. Our model incorporates the effects of adaptability into the cellular automaton models of traffic flow and simulation results adopting this optimal information feedback strategy have demonstrated high efficiency in controlling spatial distribution of traffic patterns compared with the other three information feedback strategies, i.e., vehicle number and flux.

  20. Psychobiology of depression/distress in congestive heart failure

    PubMed Central

    Hassan, Mustafa; Sheps, David S.

    2011-01-01

    Heart failure affects millions of Americans and new diagnosis rates are expected to almost triple over the next 30 years as our population ages. Affective disorders including clinical depression and anxiety are common in patients with congestive heart failure. Furthermore, the presence of these disorders significantly impacts quality of life, medical outcomes, and healthcare service utilization. In recent years, the literature has attempted to describe potential pathophysiologic mechanisms relating affective disorders and psychosocial stress to heart failure. Several potential mechanisms have been proposed including autonomic nervous system dysfunction, inflammation, cardiac arrhythmias, and altered platelet function. These mechanisms are reviewed in this article. Additional novel mechanisms such as mental stress-induced myocardial ischemia are also discussed. PMID:18368481

  1. Congestive heart failure from suspected ductal closure in utero.

    PubMed

    Arcilla, R A; Thilenius, O G; Ranniger, K

    1969-07-01

    This is the 1st case report of a ductal closure occurring during fetal growth. The case was a spontaneous delivery in cephalic presentation from a 31-year-old gravida 3, para 3 Black woman who had been treated with isoniazid and spreptomycin up to 2 months before her delivery. Gestational age was 37 weeks when the fetus was delivered weighing 3.15 kgm. The cord had been wrapped around the fetus's neck, and breathing was delayed 2 minutes. In the nursery, the baby's general condition was poor, and congestive heart failure was diagnosed. The newborn had trieuspid insufficiency, severe heart failure, and acidosis at birth. These disappeared the next day. Hemodynamic studies when the baby was 4 hours old showed a large cone-shaped ductus arteriousus extending from the pulmonary artery but ending blindly at the aortic end.

  2. Enhanced TCP Congestion Control with Higher Utilization in Under-Buffered Links

    NASA Astrophysics Data System (ADS)

    Hyun, Dowon; Jang, Ju Wook

    TCP Reno is not fully utilized in under-buffered links. We propose a new TCP congestion control algorithm that can utilize the link almost up to 100% except the first congestion avoidance cycle. Our scheme estimates the minimum congestion window size for full link utilization in every congestion avoidance cycle and sends extra packets without touching TCP Reno congestion control. It has the same RTT fairness and the same saw-tooth wave as TCP Reno does. Our scheme does not affect competing TCP Reno flows since it uses only unused link capacity. We provide a simple mathematical modeling as well as ns-2 simulation results which show that the link utilization is improved by up to 19.88% for k=1/8 against TCP Reno when the buffer is k times the optimal buffer size. We claim that our scheme is useful for transmitting large amount of data in under-buffered links.

  3. Estimation of congestion in free disposal hull models using data envelopment analysis.

    PubMed

    Abbasi, M; Jahanshahloo, G R; Rostamy-Malkhlifeh, M; Hosseinzadeh Lotfi, F

    2014-01-01

    This paper deals with evaluating congestion in free disposal hull (FDH) models. There are several approaches in data envelopment analysis (DEA) literatures which discuss the theory and application of congestion. However, almost all of these approaches considered convex DEA technologies. So, in the case of nonconvex technologies, including FDH technology, this field is almost nil. This paper makes an attempt to fill in this void. To do so, this study provides a pairwise comparisons-based algorithm to evaluate congestion in FDH model. This algorithm identifies the sources of congestion and estimates its amounts. It is also capable of detecting the losses amounts of output due to congestion. The validity of the proposed model is demonstrated using some numerical and empirical examples.

  4. Clustering and congestion effects on cascading failures of scale-free networks

    NASA Astrophysics Data System (ADS)

    Zheng, J.-F.; Gao, Z.-Y.; Zhao, X.-M.

    2007-09-01

    In this work, we study cascading failures of scale-free networks by considering congestion effects, which should be very common in the transportation or communication systems. In terms of User Equilibrium condition, congestion effects can be described by cost functions or link performance functions, which map link flows to travel times. The cost on the link represents the travel time when passing through the link. Betweenness centrality of the link is introduced to define the "practical capacity" of the link in the cost function. Different from betweeness centrality, by considering congestion effects, load dynamics can be determined in a more meaningful way. Simulation results indicate that, due to congestion effects, load distribution may become sensitive to the initial node removals for the scale-free networks. Moreover, based on congestion effects, scale-free networks with larger clustering coefficients are more sensitive to cascading failures.

  5. Development of a mechanical device to replace medicinal leech (Hirudo medicinalis) for treatment of venous congestion.

    PubMed

    Conforti, Michael L; Connor, Nadine P; Heisey, Dennis M; Vanderby, Ray; Kunz, David; Hartig, Gregory K

    2002-01-01

    Medicinal leeches are used to treat venous congestion, a complication of reconstructive surgery. Despite substantial drawbacks of leeching, little progress has been made to develop a device that would replace the leech for this purpose. The goal of this study was to develop and test mechanical prototypes for the treatment of venous congestion. We tested four prototypes (1, 2, 3a, and 3b) using congested fasciocutaneous flaps in swine. Blood removed by each prototype was measured for up to 4 hours. On average, the four prototypes removed 609%, 644%, 853%, and 811% more blood, respectively, from congested flaps versus a leech. Prototypes 3a and 3b, which allowed for innovative subcutaneous chemical (3a and 3b) and mechanical (3b) anticoagulation at the bleeding wound, sustained high levels of blood removal for up to 4 hours. Thus, a mechanical device can potentially replace the use of leeches for treating venous congestion.

  6. Road Environments: Impact of Metals on Human Health in Heavily Congested Cities of Poland

    PubMed Central

    Adamiec, Ewa

    2017-01-01

    Road dust as a by-product of exhaust and non-exhaust emissions can be a major cause of systemic oxidative stress and multiple disorders. Substantial amounts of road dust are repeatedly resuspended, in particular at traffic lights and junctions where more braking is involved, causing potential threat to pedestrians, especially children. In order to determine the degree of contamination in the heavily traffic-congested cities of Poland, a total of 148 samples of road dust (RD), sludge from storm drains (SL) and roadside soil (RS) were collected. Sixteen metals were analysed using inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma atomic emission spectroscopy (ICP-OES) and atomic absorption spectroscopy (AAS) in all samples. Chemical evaluation followed by Principal Component Analysis (PCA) revealed that road environments have been severely contaminated with traffic-related elements. Concentration of copper in all road-environment samples is even higher, exceeding even up to 15 times its average concentrations established for the surrounding soils. Non-carcinogenic health risk assessment revealed that the hazard index (HI) for children in all road-environment samples exceeds the safe level of 1. Therefore, greater attention should be paid to potential health risks caused by the ingestion of traffic-related particles during outdoor activities. PMID:28661464

  7. Road Environments: Impact of Metals on Human Health in Heavily Congested Cities of Poland.

    PubMed

    Adamiec, Ewa

    2017-06-29

    Road dust as a by-product of exhaust and non-exhaust emissions can be a major cause of systemic oxidative stress and multiple disorders. Substantial amounts of road dust are repeatedly resuspended, in particular at traffic lights and junctions where more braking is involved, causing potential threat to pedestrians, especially children. In order to determine the degree of contamination in the heavily traffic-congested cities of Poland, a total of 148 samples of road dust (RD), sludge from storm drains (SL) and roadside soil (RS) were collected. Sixteen metals were analysed using inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma atomic emission spectroscopy (ICP-OES) and atomic absorption spectroscopy (AAS) in all samples. Chemical evaluation followed by Principal Component Analysis (PCA) revealed that road environments have been severely contaminated with traffic-related elements. Concentration of copper in all road-environment samples is even higher, exceeding even up to 15 times its average concentrations established for the surrounding soils. Non-carcinogenic health risk assessment revealed that the hazard index (HI) for children in all road-environment samples exceeds the safe level of 1. Therefore, greater attention should be paid to potential health risks caused by the ingestion of traffic-related particles during outdoor activities.

  8. Spontaneous closure of the human fetal ductus arteriosus--A cause of fetal congestive heart failure.

    PubMed

    Hofstadler, G; Tulzer, G; Altmann, R; Schmitt, K; Danford, D; Huhta, J C

    1996-03-01

    Closure of the fetal ductus arteriosus, which is usually due to nonsteroidal antiinflammatory agents, may be detrimental. Therefore prenatal and postnatal clinical and echocardiographic findings in four human fetuses with spontaneous ductus arteriosus occlusion are reported. Echocardiographic and clinical data were retrospectively analyzed. Spontaneous closure of the ductus arterious was discovered in four fetuses (gestational age 34 to 38 weeks). No mother had received nonsteroidal antiinflammatory agents. Enlargement of the right heart and pulmonary arteries and tricuspid and pulmonary regurgitation were present in all cases. Two fetuses had right ventricular hypertension. Postnatally their right ventricular function recovered promptly. The others had severe right heart failure with abnormal umbilical venous pulsations. After immediate delivery none had signs of persistent pulmonary hypertension. However, they have echocardiographic evidence of right ventricular dysfunction 2 to 6 months after delivery. Occlusion of the fetal ductus arteriosus may also occur in the absence of treatment with nonsteroidal antiinflammatory agents. Immediate delivery resulted in good clinical outcome, although right ventricular dysfunction may persist.

  9. Clinical and echocardiographic characteristics and outcomes in congestive heart failure at the Hospital of The State University of Haiti.

    PubMed

    Malebranche, Rodolphe; Tabou Moyo, Christian; Morisset, Paul-Henry; Raphael, Nernst-Atwood; Wilentz, James Robert

    2016-08-01

    This study aimed to evaluate the clinical and epidemiologic profile of congestive heart failure at the principal free-care hospital in Haiti. Cardiovascular disease represents the most prevalent cause of admissions to the medical service of the University Hospital of the State of Haiti. No previous study has examined the demographics of congestive heart failure in urban Haiti. Two hundred forty-seven patients presented to the inpatient service between May 2011 and May 2013. Evaluation included history and physical, CBC, renal/metabolic profile, serum glucose, anti-HIV antibody, ECG, chest radiograph and echocardiogram. Treatment included angiotensin converting enzyme inhibitors, furosemide and spironolactone, carvedilol, digoxin and anticoagulation. Women (62.4%) outnumbered men; patients were relatively young (mean age 50.1) and from the lowest socio-economic levels of the population. Nearly all (98.8%) presented with NYHA III-IV status, with correspondingly high mortality (23.3%). Echocardiography showed 73% dilated cardiomyopathy; 83% showed moderate to severe LV systolic dysfunction (mean EF 36.5 +/- 15%) and 17% preserved LV systolic function. The three principal etiologies were dilated cardiomyopathy (29%) hypertensive cardiomyopathy (27%) and peripartum cardiomyopathy (20%). Ischemic cardiomyopathy was rare (3.4%). At 27 months follow-up, 76.7% of the patients were alive and well. Among those who died, mean survival time was 113 days. Readmission carried a poor prognosis. This congestive heart failure study from Haiti shows an unusually high proportion of young women, primarily due to peripartum cardiomyopathy. Ischemic cardiomyopathy is rare, as in Africa. Further study is warranted to address the particular problem of the high frequency of peripartum cardiomyopathy in this population. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Efficacy of pimobendan on survival and reoccurrence of pulmonary edema in canine congestive heart failure

    PubMed Central

    MIZUNO, Masashi; YAMANO, Shigeki; CHIMURA, Shuichi; HIRAKAWA, Atsushi; TAKUSAGAWA, Yoshimi; SAWADA, Tamotsu; MAETANI, Shigeki; TAKAHASHI, Arane; MIZUNO, Takeshi; HARADA, Kayoko; SHINODA, Asako; UCHIDA, Shuhei; TAKEUCHI, Junichiro; MIZUKOSHI, Takahiro; ENDO, Masaaki; UECHI, Masami

    2016-01-01

    The aim of this study was to evaluate the efficacy of pimobendan with conventional therapies on survival and reocurrence of pulmonary edema in dogs with congestive heart failure (CHF) caused by myxomatous mitral valve disease (MMVD). Records of 197 client-owned dogs from 14 veterinary hospitals were included in this study. Dogs were administered conventional treatments with or without pimobendan. Sixty-four dogs received a standard dose of pimobendan (0.20–0.48 mg/kg every 12 hr (q12hr)), 49 dogs received a low dose of pimobendan (0.05–0.19 mg/kg q12hr), and 84 dogs received conventional therapy alone. Dogs in the standard-dose and low-dose pimobendan groups had significantly longer median survival times than dogs in the conventional group (334, 277 and 136 days, respectively; P<0.001). The reoccurrence rate of pulmonary edema in the standard-dose group was significantly lower than in the low-dose and conventional groups (43%, 59% and 62%, respectively; P<0.05). Combination of pimobendan with a conventional treatment regimen significantly prolonged survival time after an initial episode of pulmonary edema in dogs with CHF caused by MMVD. There was no difference in survival between dogs administered standard and low doses of pimobendan, but pimobendan did prevent the reoccurrence of pulmonary edema in a dose-dependent manner. PMID:27644192

  11. Disparities in Patterns of Health Care Travel Among Inpatients Diagnosed With Congestive Heart Failure, Florida, 2011

    PubMed Central

    Xierali, Imam M.

    2015-01-01

    Introduction Congestive heart failure (CHF) is a major public health problem in the United States and is a leading cause of hospitalization in the elderly population. Understanding the health care travel patterns of CHF patients and their underlying cause is important to balance the supply and demand for local hospital resources. This article explores the nonclinical factors that prompt CHF patients to seek distant instead of local hospitalization. Methods Local hospitalization was defined as inpatients staying within hospital service areas, and distant hospitalization was defined as inpatients traveling outside hospital service areas, based on individual hospital discharge data in 2011 generated by a Dartmouth–Swiss hybrid approach. Multiple logistic and linear regression models were used to compare the travel patterns of different groups of inpatients in Florida. Results Black patients, no-charge patients, patients living in large metropolitan areas, and patients with a low socioeconomic status were more likely to seek local hospitalization than were white patients, those who were privately insured, those who lived in rural areas, and those with a high socioeconomic status, respectively. Conclusion Findings indicate that different populations diagnosed with CHF had different travel patterns for hospitalization. Changes or disruptions in local hospital supply could differentially affect different groups in a population. Policy makers could target efforts to CHF patients who are less likely to travel to seek treatment. PMID:26378896

  12. Efficacy of pimobendan on survival and reoccurrence of pulmonary edema in canine congestive heart failure.

    PubMed

    Mizuno, Masashi; Yamano, Shigeki; Chimura, Shuichi; Hirakawa, Atsushi; Takusagawa, Yoshimi; Sawada, Tamotsu; Maetani, Shigeki; Takahashi, Arane; Mizuno, Takeshi; Harada, Kayoko; Shinoda, Asako; Uchida, Shuhei; Takeuchi, Junichiro; Mizukoshi, Takahiro; Endo, Masaaki; Uechi, Masami

    2017-01-20

    The aim of this study was to evaluate the efficacy of pimobendan with conventional therapies on survival and reocurrence of pulmonary edema in dogs with congestive heart failure (CHF) caused by myxomatous mitral valve disease (MMVD). Records of 197 client-owned dogs from 14 veterinary hospitals were included in this study. Dogs were administered conventional treatments with or without pimobendan. Sixty-four dogs received a standard dose of pimobendan (0.20-0.48 mg/kg every 12 hr (q12hr)), 49 dogs received a low dose of pimobendan (0.05-0.19 mg/kg q12hr), and 84 dogs received conventional therapy alone. Dogs in the standard-dose and low-dose pimobendan groups had significantly longer median survival times than dogs in the conventional group (334, 277 and 136 days, respectively; P<0.001). The reoccurrence rate of pulmonary edema in the standard-dose group was significantly lower than in the low-dose and conventional groups (43%, 59% and 62%, respectively; P<0.05). Combination of pimobendan with a conventional treatment regimen significantly prolonged survival time after an initial episode of pulmonary edema in dogs with CHF caused by MMVD. There was no difference in survival between dogs administered standard and low doses of pimobendan, but pimobendan did prevent the reoccurrence of pulmonary edema in a dose-dependent manner.

  13. Congestive hepatic fibrosis score: a novel histologic assessment of clinical severity.

    PubMed

    Dai, Dao-Fu; Swanson, Paul E; Krieger, Eric V; Liou, Iris W; Carithers, Robert L; Yeh, Matthew M

    2014-12-01

    Chronic right heart failure predisposes to hepatic passive congestion and centrizonal necrosis that may lead to hepatic fibrosis (cardiac sclerosis). Although there have been several studies on the histologic features of congestive hepatopathy, there is no available grading system. In this study we developed a novel grading system for congestive hepatic fibrosis. Liver biopsies were examined in patients with chronic heart failure of various etiologies including congenital heart disease, idiopathic cardiomyopathy, ischemic heart disease, and valvular heart disease. The cases with available echocardiography and/or right heart catheterization were included. Cases with other types of underlying chronic liver diseases, alcoholic liver disease, significant steatosis (>20%), malignant neoplasm, and acute heart failure or shock were excluded. After exclusion, 42 cases were included in the study. We herein proposed a novel congestive hepatic fibrosis score and correlated it with the right heart structure and function obtained by echocardiography and/or right heart catheterization. Our results showed that congestive hepatic fibrosis score is well correlated with the right atrial pressure (P for trend <0.001). The presence of portal fibrosis (congestive hepatic fibrosis scores 2 and 3) is associated with significantly higher right atrial pressure than those with no fibrosis (P<0.001) or with centrizonal fibrosis only (P=0.02). Congestive hepatic fibrosis score is also significantly associated with increasing severity of right atrial dilatation (P=0.03) and right ventricular dilatation (P=0.02), indicators for chronic volume and/or pressure overload. Other histopathologic features include sinusoidal dilatation and centrizonal hepatocyte atrophy. In summary, although sinusoidal dilatation and centrizonal fibrosis are the hallmarks of hepatic passive congestion, the presence of portal fibrosis is suggestive of more advanced disease, as it correlates with more severe impairment

  14. The effects of congestions tax on air quality and health

    NASA Astrophysics Data System (ADS)

    Johansson, Christer; Burman, Lars; Forsberg, Bertil

    The "Stockholm Trial" involved a road pricing system to improve the air quality and reduce traffic congestion. The test period of the trial was January 3-July 31, 2006. Vehicles travelling into and out of the charge cordon were charged for every passage during weekdays. The amount due varied during the day and was highest during rush hours (20 SEK = 2.2 EUR, maximum 60 SEK per day). Based on measured and modelled changes in road traffic it was estimated that this system resulted in a 15% reduction in total road use within the charged cordon. Total traffic emissions in this area of NO x and PM10 fell by 8.5% and 13%, respectively. Air quality dispersion modelling was applied to assess the effect of the emission reductions on ambient concentrations and population exposure. For the situations with and without the trial, meteorological conditions and other emissions than from road traffic were kept the same. The calculations show that, with a permanent congestion tax system like the Stockholm Trial, the annual average NO x concentrations would be lower by up to 12% along the most densely trafficked streets. PM10 concentrations would be up to 7% lower. The limit values for both PM10 and NO 2 would still be exceeded along the most densely trafficked streets. The total population exposure of NO x in Greater Stockholm (35 × 35 km with 1.44 million people) is estimated to decrease with a rather modest 0.23 μg m -3. However, based on a long-term epidemiological study, that found an increased mortality risk of 8% per 10 μg m -3 NO x, it is estimated that 27 premature deaths would be avoided every year. According to life-table analysis this would correspond to 206 years of life gained over 10 years per 100 000 people following the trial if the effects on exposures would persist. The effect on mortality is attributed to road traffic emissions (likely vehicle exhaust particles); NO x is merely regarded as an indicator of traffic exposure. This is only the tip of the ice

  15. Diagnosis and Treatment of Depression in Patients With Congestive Heart Failure: A Review of the Literature

    PubMed Central

    Stern, Theodore A.; Hebert, Kathy A.; Musselman, Dominique L.

    2013-01-01

    Context: Major depressive disorder (MDD) can be challenging to diagnose in patients with congestive heart failure, who often suffer from fatigue, insomnia, weight changes, and other neurovegetative symptoms that overlap with those of depression. Pathophysiologic mechanisms (eg, inflammation, autonomic nervous system dysfunction, cardiac arrhythmias, and altered platelet function) connect depression and congestive heart failure. Objective: We sought to review the prevalence, diagnosis, neurobiology, and treatment of depression associated with congestive heart failure. Data Sources: A search of all English-language articles between January 2003 and January 2013 was conducted using the search terms congestive heart failure and depression. Study Selection: We found 1,498 article abstracts and 19 articles (meta-analyses, systematic reviews, and original research articles) that were selected for inclusion, as they contained information about our focus on diagnosis, treatment, and pathophysiology of depression associated with congestive heart failure. The search was augmented with manual review of reference lists of articles from the initial search. Articles selected for review were determined by author consensus. Data Extraction: The prevalence, diagnosis, neurobiology, and treatment of depression associated with congestive heart failure were reviewed. Particular attention was paid to the safety, efficacy, and tolerability of antidepressant medications commonly used to treat depression and how their side-effect profiles impact the pathophysiology of congestive heart failure. Drug-drug interactions between antidepressant medications and medications used to treat congestive heart failure were examined. Results: MDD is highly prevalent in patients with congestive heart failure. Moreover, the prevalence and severity of depression correlate with the degree of cardiac dysfunction and development of congestive heart failure. Depression increases the risk of congestive heart

  16. Quantum random walks on congested lattices and the effect of dephasing

    PubMed Central

    Motes, Keith R.; Gilchrist, Alexei; Rohde, Peter P.

    2016-01-01

    We consider quantum random walks on congested lattices and contrast them to classical random walks. Congestion is modelled on lattices that contain static defects which reverse the walker’s direction. We implement a dephasing process after each step which allows us to smoothly interpolate between classical and quantum random walks as well as study the effect of dephasing on the quantum walk. Our key results show that a quantum walker escapes a finite boundary dramatically faster than a classical walker and that this advantage remains in the presence of heavily congested lattices. PMID:26812924

  17. Reliable on-demand multicast routing with congestion control in wireless ad hoc networks

    NASA Astrophysics Data System (ADS)

    Tang, Ken; Gerla, Mario

    2001-07-01

    In this paper, we address the congestion control multicast routing problem in wireless ad hoc networks through the medium access control (MAC) layer. We first introduce the Broadcast Medium Window (BMW) MAC protocol, which provides reliable delivery to broadcast packets at the MAC layer. We then extend the wireless On-Demand Multicast Routing Protocol (ODMRP) to facilitate congestion control in ad hoc networks using BMW. Through simulation, we show that ODMRP with congestion control adapts well to multicast sources that are aggressive in data transmissions.

  18. Chronic vagal stimulation in patients with congestive heart failure.

    PubMed

    De Ferrari, Gaetano M; Sanzo, Antonio; Schwartz, Peter J

    2009-01-01

    Increased sympathetic and reduced vagal activity predict increased mortality in patients with congestive heart failure (CHF). Experimentally, vagal stimulation (VS) is protective both during acute myocardial ischemia and in chronic heart failure. In man, VS is used in refractory epilepsy but has never been used in cardiovascular diseases. Thus, there is a strong rationale to investigate the effects of chronic VS in patients with CHF. We assesses the feasibility and safety of chronic VS with CardioFit (BioControl Medical), a VS implantable system delivering pulses synchronous with heart beats to the right cervical vagus nerve in a preliminary pilot study in eight advanced CHF patients with favorable results, and subsequently in a larger multicenter study. Overall, 32 patients have been successfully implanted (mostly in NYHA Class III; mean age 56 years, ischemic etiology in 69%; prior implantable cardioverter-defibrillator (ICD) in 63%; concomitant beta blocker and angiotensin converting enzyme inhibitor (ACE-I) or angiotensin receptor blocker (ARB) in 100%). Preliminary results confirm feasibility of the study, an acceptable side effect profile and promising preliminary efficacy data. Several mechanisms may contribute to the beneficial effect observed in patients with heart failure. Should these results be confirmed in larger controlled studies, chronic vagal stimulation could be a further treatment option for CHF patients, possibly integrated with defibrillator and resynchronization therapies.

  19. Scheduled Controller Design of Congestion Control Considering Network Resource Constraints

    NASA Astrophysics Data System (ADS)

    Naito, Hiroyuki; Azuma, Takehito; Fujita, Masayuki

    In this paper, we consider a dynamical model of computer networks and derive a synthesis method for congestion control. First, we show a model of TCP/AQM (Transmission Control Protocol/Active Queue Management) as a dynamical model of computer networks. The dynamical model of TCP/AQM networks consists of models of TCP window size, queue length and AQM mechanisms. Second, we propose to describe the dynamical model of TCP/AQM networks as linear systems with self-scheduling parameters, which also depend on information delay. Here we focus on the constraints on the maximum queue length and TCP window-size, which are the network resources in TCP/AQM networks. We derive TCP/AQM networks as the LPV system (linear parameter varying system) with information delay and self-scheduling parameter. We design a memoryless state feedback controller of the LPV system based on a gain-scheduling method. Finally, the effectiveness of the proposed method is evaluated by using MATLAB and the well-known ns-2 (Network Simulator Ver.2) simulator.

  20. Prognosis and possible presymptomatic manifestations of congestive cardiomyopathy (COCM).

    PubMed Central

    Kuhn, H.; Breithardt, G.; Knieriem, H. J.; Köhler, E.; Lösse, B.; Seipel, L.; Loogen, F.

    1978-01-01

    In order to find evidence of prognosis and of presymptomatic manifestation of congestive cardiomyopathy (COCM) in fifty-eight patients, the extent of morphological changes of endomyocardial catheter biopsy (EMCB), clinical and haemodynamic data were correlated to the clinical course. In addition, clinical, haemodynamic, angiographic, morphological and His-bundle electrographic studies were performed in patients with left bundle branch block (LBBB), normal left ventricular end-diastolic volume, and normal coronary arteries (n = 43). Related to a 10-year mortality rate of 70% from the onset of symptoms, COCM is one of the most severe heart diseases. Endomyocardial catheter biopsy (EMCB) allowed clear prognostic separation in patients with COCM and seems to be of diagnostic value in patients with only slightly enlarged hearts and in patients with a short history of symptoms. The studies also revealed much evidence that at least some patients with LBBB, normal left ventricular end-diastolic volume (LVEDV) and normal coronary arteries exhibit an early stage of COCM. In these patients especially EMCB with severe changes of heart muscle cells and/or impaired left ventricular function may indicate subsequent COCM. So that there is now a new indication for performing EMCB. PMID:704515

  1. Body fluid distribution in elderly subjects with congestive heart failure.

    PubMed

    Sergi, Giuseppe; Lupoli, Lucia; Volpato, Stefania; Bertani, Roberta; Coin, Alessandra; Perissinotto, Egle; Calliari, Irene; Inelmen, Emine Meral; Busetto, Luca; Enzi, Giuliano

    2004-01-01

    The aims of this study were to investigate body fluid changes in elderly patients suffering from congestive heart failure (CHF) and to identify the fluid measurement that best characterizes fluid overload states in CHF patients by comparison with normal hydration in the elderly. In a case-controlled experimental design, 72 elderly subjects (65-98 yr), 38 healthy and 34 with CHF, were studied. Total body water (TBW) and extracellular water (ECW) were determined by dilution methods; fat-free mass (FFM) and fat mass (FM) were determined by dual-energy X-ray absorptiometry (DEXA). In healthy subjects, the FFM hydration expressed as TBW% FFM (males 72.0 +/- 4.3 vs females 72.4 +/- 5.0%) and ECW% TBW (males 47.3 +/- 3.4 vs females 47.8 +/- 5.1) were similar in both genders. ECW in liters for FFM and for TBW (ECW% TBW), corrected for body weight, was greater in the group with CHF than in the control group, in both sexes. Among the relative fluid measures, only ECW% TBW [odds ratio (OR) 1.5] independently predicted fluid retention. Having an ECW% TBW greater than 50% corresponded to an OR of about 10. In conclusion, elderly patients suffering from CHF have a characteristic increase in body fluid levels, mainly affecting the extracellular compartment, and ECW% TBW is a useful indicator of fluid retention.

  2. Atrial natriuretic factor binding sites in experimental congestive heart failure

    SciTech Connect

    Bianchi, C.; Thibault, G.; Wrobel-Konrad, E.; De Lean, A.; Genest, J.; Cantin, M. )

    1989-10-01

    A quantitative in vitro autoradiographic study was performed on the aorta, renal glomeruli, and adrenal cortex of cardiomyopathic hamsters in various stages of heart failure and correlated, in some instances, with in vivo autoradiography. The results indicate virtually no correlation between the degree of congestive heart failure and the density of 125I-labeled atrial natriuretic factor ((Ser99, Tyr126)ANF) binding sites (Bmax) in the tissues examined. Whereas the Bmax was increased in the thoracic aorta in moderate and severe heart failure, there were no significant changes in the zona glomerulosa. The renal glomeruli Bmax was lower in mild and moderate heart failure compared with control and severe heart failure. The proportion of ANF B- and C-receptors was also evaluated in sections of the aorta, adrenal, and kidney of control and cardiomyopathic hamsters with severe heart failure. (Arg102, Cys121)ANF (des-(Gln113, Ser114, Gly115, Leu116, Gly117) NH2) (C-ANF) at 10(-6) M displaced approximately 505 of (Ser99, Tyr126)125I-ANF bound in the aorta and renal glomeruli and approximately 20% in the adrenal zona glomerulosa in both series of animals. These results suggest that ANF may exert a buffering effect on the vasoconstriction of heart failure and to a certain extent may inhibit aldosterone secretion. The impairment of renal sodium excretion does not appear to be related to glomerular ANF binding sites at any stage of the disease.

  3. Practical Rate-Based Congestion Control for Wireless Mesh Networks

    NASA Astrophysics Data System (ADS)

    Elrakabawy, Sherif M.; Lindemann, Christoph

    We introduce an adaptive pacing scheme to overcome the drawbacks of TCP in wireless mesh networks with Internet connectivity. The pacing scheme is implemented at the wireless TCP sender as well as at the mesh gateway, and reacts according to the direction of TCP flows running across the wireless network and the Internet. TCP packets are transmitted rate-based within the TCP congestion window according to the current out-of-interference delay and the coefficient of variation of recently measured round-trip times. Opposed to the majority of previous work which builds on simulations, we implement a Linux prototype of our approach and evaluate its feasibility in a real 20-node mesh testbed. In an experimental performance study, we compare the goodput and fairness of our approach against the widely deployed TCP NewReno. Experiments show that our approach, which we denote as Mesh Adaptive Pacing (MAP), can achieve up to 150% more goodput than TCP NewReno and significantly improves fairness between competing flows. MAP is incrementally deployable since it is TCP-compatible, does not require cross-layer information from intermediate nodes along the path, and requires no modifications in the wired domain.

  4. Optimal information transmission in organizations: search and congestion

    SciTech Connect

    Arenas, A.; Cabrales, A.; Danon, L.; Diaz-Guilera, A.; Guimera, R.; Vega-Redondo, F.

    2008-01-01

    We propose a stylized model of a problem-solving organization whose internal communication structure is given by a fixed network. Problems arrive randomly anywhere in this network and must find their way to their respective specialized solvers by relying on local information alone. The organization handles multiple problems simultaneously. For this reason, the process may be subject to congestion. We provide a characterization of the threshold of collapse of the network and of the stock of floating problems (or average delay) that prevails below that threshold. We build upon this characterization to address a design problem: the determination of what kind of network architecture optimizes performance for any given problem arrival rate. We conclude that, for low arrival rates, the optimal network is very polarized (i.e. star-like or centralized), whereas it is largely homogeneous (or decentralized) for high arrival rates. These observations are in line with a common transformation experienced by information-intensive organizations as their work flow has risen in recent years.

  5. Pelvic congestion syndrome masquerading as osteoarthritis of the hip

    PubMed Central

    Dos Santos, Scott J; Whiteley, Mark S

    2016-01-01

    Objectives: Pelvic congestion syndrome (PCS) is associated with pelvic vein reflux (PVR), occasionally secondary to venous compression. Its symptoms, usually intra-pelvic, are alleviated following the abolition of this reflux by pelvic vein embolisation (PVE). The objective of this report is to present two cases of left hip pain, erroneously diagnosed as osteoarthritis, which disappeared after successful PVE and abolition of PVR. Methods: Two females presented with lower limb varicose veins, and also had a history of left-sided hip pain. Both had previously been investigated for the hip pain and diagnosed as osteoarthritis despite minimal arthritic changes on pelvic X-rays. During investigation for lower limb varicose veins, both showed a pelvic origin for their leg veins and hence underwent transvaginal duplex ultrasound. This revealed PVR, and PVE was planned in both patients. Results: Both patients underwent PVE and reported ‘miraculous’ resolution of left hip pain and also PCS symptoms including pelvic pain, irritable bowel issues and the disappearance of pelvic dragging, with almost immediate disappearance of vulval and vaginal varicosities. One patient also noted reduced clitoral sensitivity. Conclusion: Manifestations of PCS may vary in terms of intra- or extra-pelvic signs. PCS and PVR should be considered in the differential diagnosis of patients with arthritic symptoms in the hip without evident radiographic evidence. PMID:27994874

  6. Cheyne-Stokes respiration in patients with congestive heart failure.

    PubMed

    Brack, Thomas

    2003-12-13

    Cheyne-Stokes Respiration (CSR) is a breathing pattern characterised by rhythmic oscillation of tidal volume with regularly recurring periods of hyperpnoea, hypopnoea and apnoea. CSR is no longer solely regarded as a symptom of severe congestive heart failure (CHF), but has been recognised as an independent risk factor for worsening heart failure and reduced survival in patients with CHF. CSR is associated with frequent awakening that fragment sleep and with concomitant sympathetic activation both of which may worsen CHF. Cheyne-Stokes Respiration is very common in patients with severe CHF and its prevalence may have been underestimated in the past due to technical limitations that precluded respiratory monitoring outside sleep laboratories. Since treatment of CSR appears to be beneficial and safe, patients at risk should be promptly diagnosed and treated. Treatment of CSR has been demonstrated to improve left ventricular ejection fraction and potentially prolongs survival in patients with severe CHF. This article briefly summarises the current knowledge of the patho-physiology, prevalence and therapy of Cheyne-Stokes respiration.

  7. A perspective on the surgical management of congestive heart failure.

    PubMed

    Massad, Malek G; Prasad, Sunil M; Chedrawy, Edgar G; Lele, Himalaya

    2008-03-01

    Surgical treatment of patients with congestive heart failure (CHF) has steadily advanced from rescue procedures such as aneurysmectomy, rupture repair, ventricular assist devices (VADs), and transplantation to procedures that can prevent or delay the progression of cardiac dysfunction and failure. The latter include operations such as coronary artery bypass grafting (CABG) and mitral valve repair for patients with ischemic cardiomyopathy (ICMP) and mitral annular dilatation, ventricular restoration and remodeling, and cardiac resynchronization therapy. As the number of heart transplants reported worldwide continues to decline over the past decade (by over 30%), newer surgical therapies have emerged. A need arises for clinical registries such as the NIH-sponsored LVAD registry and registries for biventricular pacing and AICD implantation, for total artificial heart implants, and for mitral valve repair in patients with ICMP. Prospective trials comparing sole ventricular restoration therapy (SVR) to SVR with concomitant CABG/MVR, coronary sinus versus epicardial LV pacing for ventricular resynchronization therapy, trials comparing LVAD as destination therapy to AICD implants, mitral valve repair versus chordal-sparing valve replacement for ischemic and valvular cardiomyopathy, and off-pump versus on-pump CABG for patients with ICMP are urgently needed. Future research should also be directed toward drugs targeting "B-cell mediated" humeral vascular rejection--the Achilles heel of cardiac transplantation, xenotransplantation, permanently implantable VADs, gene therapy, and myocardial cell regeneration therapy.

  8. Decrease of cardiac chaos in congestive heart failure

    NASA Astrophysics Data System (ADS)

    Poon, Chi-Sang; Merrill, Christopher K.

    1997-10-01

    The electrical properties of the mammalian heart undergo many complex transitions in normal and diseased states. It has been proposed that the normal heartbeat may display complex nonlinear dynamics, including deterministic chaos,, and that such cardiac chaos may be a useful physiological marker for the diagnosis and management, of certain heart trouble. However, it is not clear whether the heartbeat series of healthy and diseased hearts are chaotic or stochastic, or whether cardiac chaos represents normal or abnormal behaviour. Here we have used a highly sensitive technique, which is robust to random noise, to detect chaos. We analysed the electrocardiograms from a group of healthy subjects and those with severe congestive heart failure (CHF), a clinical condition associated with a high risk of sudden death. The short-term variations of beat-to-beat interval exhibited strongly and consistently chaotic behaviour in all healthy subjects, but were frequently interrupted by periods of seemingly non-chaotic fluctuations in patients with CHF. Chaotic dynamics in the CHF data, even when discernible, exhibited a high degree of random variability over time, suggesting a weaker form of chaos. These findings suggest that cardiac chaos is prevalent in healthy heart, and a decrease in such chaos may be indicative of CHF.

  9. Management of anemia in patients with congestive heart failure.

    PubMed

    Tim Goodnough, Lawrence; Comin-Colet, Josep; Leal-Noval, Santiago; Ozawa, Sherri; Takere, Jacqueline; Henry, David; Javidroozi, Mazyar; Hohmuth, Benjamin; Bisbe, Elvira; Gross, Irwin; Shander, Aryeh

    2017-01-01

    Anemia is an independent risk factor for adverse patient outcomes. There are no guidelines for management of anemia in patients with congestive heart failure (CHF), despite its high incidence. Four objectives were defined by the International Anemia Management and Clinical Outcomes Expert Panel (AMCO), a multinational group of interdisciplinary experts identified by the Society for the Advancement of Blood Management (SABM) to: determine the prevalence of anemia in outpatients; to determine the prevalence of hospital-acquired anemia; to assess the impact of anemia management on clinical outcomes such as quality of life and functional status; and to provide recommendations for primary care physicians and specialists for the diagnosis, evaluation, and management of anemia in patients with CHF. Anemia and iron deficiency were confirmed to be highly prevalent in patients with CHF. Intravenous iron therapy improves anemia, cardiac function and exercise tolerance, leading to improvement in quality of life. Anemia management has been demonstrated to be cost-effective. Clinical care pathways to manage anemia in patients with CHF are recommended as best practices in order to improve patient outcomes. Am. J. Hematol. 92:88-93, 2017. © 2016 Wiley Periodicals, Inc.

  10. Congestive heart failure in children with pneumonia and respiratory failure.

    PubMed

    Nimdet, Kachaporn; Techakehakij, Win

    2017-03-01

    Congestive heart failure (CHF) is one of the most common cardiac complications of pneumonia in adulthood leading to increased risk of morbidity and mortality. Little is known, however, of CHF and pneumonia in children. The aim of this study was therefore to investigate the characteristics and factors associated with CHF in under-5 children with pneumonia and respiratory failure. A retrospective cohort was conducted in hospitalized patients aged 2-59 months with community-acquired pneumonia and respiratory failure from June 2011 to June 2014 at Suratthani Hospital, Thailand. The characteristics, therapeutic strategy, and clinical outcomes of CHF were reviewed. Baseline characteristics and basic laboratory investigations on admission were compared between the CHF and non-CHF groups. Of 135 patients, 14 (10%) had CHF. Compared with patients without CHF, the CHF group had prolonged intubation and hospital stay and high rates of associated complications such as ventilator-associated pneumonia, sepsis, shock, and 30 day mortality. CHF was significantly associated with certain characteristics, including male sex and bacterial pneumonia. Pneumonia with respiratory failure is associated with CHF even in healthy children without cardiac risks. The awareness and early recognition of CHF, particularly in male, and bacterial pneumonia, is important in order to provide immediate treatment to reduce complications. © 2016 Japan Pediatric Society.

  11. Congestive Myelopathy due to Intradural Spinal AVM Supplied by Artery of Adamkiewicz: Case Report with Brief Literature Review and Analysis of the Foix-Alajouanine Syndrome Definition.

    PubMed

    Sood, Dinesh; Mistry, Kewal A; Khatri, Garvit D; Chadha, Veenal; Garg, Swati; Suthar, Pokhraj P; Patel, Dhruv G; Patel, Ankitkumar

    2015-01-01

    Spinal arteriovenous malformations (AVMs) can lead to development of congestive myelopathy (Foix-Alajouanine syndrome). Spinal AVMs are rare and so is this syndrome. Diagnosis is often missed due to its rarity and confusing definitions of the Foix-Alajouanine syndrome. We report a case of a 47-year-old male patient suffering from this rare syndrome with an AVM arising from the artery of Adamkiewicz, which is another rarity. Our patient was treated by embolization of the lesion with 20% glue, after which he showed mild improvement of symptoms. We also present a brief review of literature on spinal AVMs and elucidate the evolution of the term Foix-Alajouanine syndrome. Use of the term "Foix-Alajouanine syndrome" should be restricted to patients with progressive subacute to chronic neurological symptoms due to congestive myelopathy caused by intradural spinal AVMs. CT angiography should supplement DSA as preliminary Imaging modality. Patients may be treated with surgery or endovascular procedures.

  12. Chance Constrained Input Relaxation to Congestion in Stochastic DEA. An Application to Iranian Hospitals.

    PubMed

    Kheirollahi, Hooshang; Matin, Behzad Karami; Mahboubi, Mohammad; Alavijeh, Mehdi Mirzaei

    2015-01-01

    This article developed an approached model of congestion, based on relaxed combination of inputs, in stochastic data envelopment analysis (SDEA) with chance constrained programming approaches. Classic data envelopment analysis models with deterministic data have been used by many authors to identify congestion and estimate its levels; however, data envelopment analysis with stochastic data were rarely used to identify congestion. This article used chance constrained programming approaches to replace stochastic models with "deterministic equivalents". This substitution leads us to non-linear problems that should be solved. Finally, the proposed method based on relaxed combination of inputs was used to identify congestion input in six Iranian hospital with one input and two outputs in the period of 2009 to 2012.

  13. Hyponatraemia and congestive heart failure refractory to diuretic treatment. Utility of tolvaptan.

    PubMed

    Pose, A; Almenar, L; Manzano, L; Gavira, J J; López Granados, A; Delgado, J; Aramburu, O; Arévalo, J C; Méndez, M; Comín, J; Manito, N

    2017-10-01

    Heart failure (HF) is currently one of the most significant healthcare problems in Spain and has a continuously increasing prevalence. Advances in our understanding of the various biological responses that promote cardiac remodelling and pulmonary venous congestion constitute the basis of current treatment. This article, prepared by members of the HF groups of the Spanish Society of Cardiology and the Spanish Society of Internal Medicine, discusses the current therapeutic strategies for patients with congestion refractory to diuretic treatment. The article includes our clinical experience with the use of tolvaptan as an additional treatment for congestion associated with hyponatraemia. To this end, we propose an algorithm for the use of tolvaptan in patients with congestive HF, natraemia <130mEq/l and poor response to conventional diuretic treatment. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  14. 78 FR 67442 - Congestion Mitigation and Air Quality Improvement Program Interim Guidance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-12

    ... Federal Highway Administration Congestion Mitigation and Air Quality Improvement Program Interim Guidance... Mitigation and Air Quality Improvement (CMAQ) Program (Interim Guidance). The Interim Guidance revises CMAQ....gov/environment/air_quality/cmaq/policy_and_guidance/2008_guidance/ guidance/. DATES: This...

  15. Effects of tolvaptan on congestive heart failure complicated with chylothorax in a neonate.

    PubMed

    Sato, Nikiko; Sugiura, Tokio; Nagasaki, Rika; Suzuki, Kazutaka; Ito, Koichi; Kato, Takenori; Inukai, Sachiko; Saitoh, Shinji

    2015-10-01

    Tolvaptan is an oral vasopressin type 2 receptor antagonist that can be used for heart failure patients with hyponatremia or symptomatic congestion. Although the effects of tolvaptan in adults have been well documented, only limited information is available in children. The case of a neonate with congestive heart failure complicated with chylothorax after palliative surgery for transposition of the great arteries treated with tolvaptan is reported. Slow up-titration to 0.1 mg/kg successfully increased urine output and improved refractory congestive heart failure without hypernatremia. Subsequently, bodyweight and chylothorax decreased gradually. Moreover, the use of tolvaptan reduced the dosage of furosemide. Tolvaptan could be an alternative drug for neonates with congestive heart failure. Further large studies are needed to confirm the efficacy and identify the appropriate dose of tolvaptan in neonates.

  16. A Study of Congestion in the Kansas City Southern Railway System

    DTIC Science & Technology

    2007-11-02

    used to test power’s relation to congestion. Friedman’s Rank Test , a nonparametric statistical model, tests the significance of power against eight...other factors in their relation to train delays. The second model tests the correlation between train time delays and number of ൬-hour cars." This...Pacific are summarized. Two quantitative models are used to test power’s relation to congestion. Friedman’s Rank Test , a nonparametric statistical model

  17. The prevalence, aetiology and treatment of congestive cardiac failure in Antigua and Barbuda.

    PubMed

    McSwain, M; Martin, T C; Amaraswamy, R

    1999-09-01

    A retrospective review of the cases of congestive heart failure admitted to Holberton Hospital in Antigua in 1995 and 1996 was undertaken. Two hundred and ninety-three (293) patients were identified by International Statistical Classification of Diseases, 10th revision (ICD-10) coding as having congestive cardiac failure in the period but only 138 charts were either available or fitted the definition of congestive cardiac failure and these provided the basis for this analysis. The average age of patients admitted for congestive cardiac failure was 69 years (range: 5 months to 99 years), and 63% were female. the aetiology of congestive cardiac failure was hypertension (41%), ischaemia (33%), valvular (12%), alcohol related (2%), idiopathic (5%) and mixed (7%). Treatment included diuretics (95%), angiotensin converting enzyme inhibitors (78%), digoxin (75%), nitrates (34%), calcium channel blockers (25%), other vasodilators (7%) and antiarrhythmics (5%). Of those with congestive heart failure, diabetes was present in 38%, atrial fibrillation in 19%, renal insufficiency in 17%, elevated cholesterol in 11%, obesity in 9% and tobacco use in 7%. The in-hospital mortality in the 2-year period was 17.4% (females 15%, males 22%, 11% < 65 years, 20% > 65 years, 14% for those with 1 to 3 admissions and 83% for those with > 3 admissions, 19% for those with atrial fibrillation and 16% for those without). The prevalence of congestive cardiac failure utilizing the data analysed in this study (138 patients) was 0.21% of the population of the island state but based on the discharge diagnosis using ICD-10 coding it was 0.5%; it was 1% in the 40 to 65-year-age group and 4% in those > 65 years of age. The patients in this study represented only those with New York Heart Association (NYHA) classes III and IV, hence the true prevalence would be higher than recorded here. Congestive cardiac failure is emerging as a significant health problem in Antigua and Barbuda.

  18. A source-based congestion control strategy for real-time video transport on IP network

    NASA Astrophysics Data System (ADS)

    Chen, Xia; Cai, Canhui

    2005-07-01

    The goal of this paper is to design a TCP friendly real-time video transport protocol that will not only utilize network resource efficiently, but also prevent network congestion from the real-time video transmitting effectively. To this end, we proposed a source based congestion control scheme to adapt video coding rate to the channel capacity of the IP network, including three stages: rate control, rate-adaptive video encoding, and rate shaping.

  19. Congestive cardiomyopathy and endobronchial granulomas as manifestations of Churg-Strauss syndrome.

    PubMed Central

    Alvarez-Sala, R.; Prados, C.; Armada, E.; Del Arco, A.; Villamor, J.

    1995-01-01

    Churg-Strauss syndrome is a systemic vasculitis. Its most frequent complications are heart diseases and asthma. Usually, cardiological manifestations are pericarditis, cardiac failure and myocardial infarction. Endobronchial granulomas identified by bronchoscopy are unusual. We present the case of a man with congestive cardiomyopathy and endobronchial granulomas macroscopically visible at bronchoscopy. After a review of medical literature, we found one case of congestive cardiomyopathy and no cases of endobronchial granulomas observed by bronchoscopy associated with Churg-Strauss syndrome. Images Figure PMID:7644400

  20. Algorithm and data support of traffic congestion forecasting in the controlled transport

    NASA Astrophysics Data System (ADS)

    Dmitriev, S. V.

    2015-06-01

    The topicality of problem of the traffic congestion forecasting in the logistic systems of product movement highways is considered. The concepts: the controlled territory, the highway occupancy by vehicles, the parking and the controlled territory are introduced. Technical realizabilityof organizing the necessary flow of information on the state of the transport system for its regulation has been marked. Sequence of practical implementation of the solution is given. An algorithm for predicting traffic congestion in the controlled transport system is suggested.

  1. Congestion of mastoid mucosa and influence on middle ear pressure - Effect of retroauricular injection of adrenaline.

    PubMed

    Fooken Jensen, Pernille Vita; Gaihede, Michael

    2016-10-01

    Micro-CT scanning of temporal bones has revealed numerous retroauricular microchannels, which connect the outer bone surface directly to the underlying mastoid air cells. Their structure and dimensions have suggested a separate vascular supply to the mastoid mucosa, which may play a role in middle ear (ME) pressure regulation. This role may be accomplished by changes in the mucosa congestion resulting in volumetric changes, which ultimately affect the pressure of the enclosed ME gas pocket (Boyle's law). Further, such mucosa congestion may be susceptible to α-adrenergic stimulation similar to the mucosa of the nose. The purpose of our study was to investigate these hypotheses by recording the ME pressure in response to adrenergic stimulation administered by retroauricular injections at the surface of the microchannels. In a group of 20 healthy adults we measured the ME pressure by tympanometry initially in the sitting position, and then in the supine position over a 5 min period with 30 s intervals. In each subject, the study included 1) a control reference experiment with no intervention, 2) a control experiment with subcutaneously retroauricular injection of 1 ml isotonic NaCl solution, and 3) a test experiment with subcutaneously retroauricular injection of 1 ml NaCl-adrenaline solution. In both control experiments the ME pressure displayed an immediate increase in response to changing body position; this pressure increase remained stable for the entire period up to five minutes. In the test experiments the ME pressure also showed an initial pressure increase, but it was followed by a distinct significant pressure decrease with a maximum after 90 s. The test group was injected with both a 5 and 10% adrenaline solution, but the responses appeared similar for the two concentrations. Subcutaneous retroauricular injection of adrenaline caused a significant pressure decrease in ME pressure compared with control ears. This may be explained by the microchannels

  2. Acute and long-term renal and metabolic effects of piretanide in congestive cardiac failure.

    PubMed Central

    McNabb, W R; Noormohamed, F H; Lant, A F

    1988-01-01

    1. The renal and metabolic effects of the sulphamoylbenzoic acid diuretic, piretanide, have been studied, under controlled dietary conditions, in 39 patients with congestive cardiac failure. 2. In acute studies, peak saluresis occurred within 4 h of oral piretanide administration; saluresis was complete within 6 h, after which a significant antidiuretic effect was observed. Addition of triamterene, 50 mg, blunted the 0-6 h kaliuretic effect of piretanide. Over 24 h, piretanide, alone, caused insignificant urinary losses of potassium when compared with control. 3. In comparative studies, the piretanide dose-response curve was found to be parallel to that of frusemide over the dose range studied. The 0-6 h saluretic responses of piretanide, 6, 12 and 18 mg, were found to be equivalent to frusemide, 40, 80 and 120 mg respectively. The collective mean ratios of all the saluretic responses to each dose of piretanide with the corresponding dose of frusemide was observed to be 0.99 +/- 0.12, over 0-6 h period, and 0.86 +/- 0.09 over the 24 h period. The relative potency of piretanide, when compared with frusemide was found to be 6.18 (95% confidence limits 4.87-8.33), over the 0-6 h period, and 4.73 (95% confidence limits 3.65-6.14), over 24 h period. 4. In 15 patients in severe cardiac failure, urinary recovery of piretanide, over first 6 h, at the start of treatment was 21.2 +/- 2.1% while efficiency of the diuretic (mmol Na/mg drug) was 47.3 +/- 4.1. Long-term piretanide therapy was continued in the same group for up to and in some cases over 3 years. No other diuretics or potassium supplements were given. Piretanide dosage ranged from 6 to 24 mg day-1 according to clinical need. Plasma potassium fell significantly at 12 and 24 months, though remaining within the normal range. At these same times, significant elevations in both plasma urate and total fasting cholesterol were observed. Two patients developed overt gout on high dose piretanide therapy (24 mg day-1

  3. Increased expression of thyroid hormone receptor isoforms in end-stage human congestive heart failure.

    PubMed

    d'Amati, G; di Gioia, C R; Mentuccia, D; Pistilli, D; Proietti-Pannunzi, L; Miraldi, F; Gallo, P; Celi, F S

    2001-05-01

    Thyroid hormone plays an important role on myocardial development and function. The local effects of thyroid hormone are mediated by the receptor isoforms ultimately driving the expression of cardiac-specific genes. Although overt and subclinical thyroid dysfunction causes well-known changes in the cardiovascular system, little is known about local thyroid hormone action in normal and failing human myocardium. With a newly developed multiplex competitive RT-PCR method, we evaluated the expression of thyroid hormone receptor (TR) isoforms alpha-1, alpha-2, and beta-1 in normal human hearts and in end-stage congestive heart failure. A statistically significant difference in the expression of all three TR isoforms was observed among samples from normal subjects, ischemic heart disease (IHD), and dilated cardiomyopathy (DCM). In DCM, compared with normal, the studied TR isoforms were significantly increased. In IHD, the increased expression was found significant only for alpha-1 and alpha-2 isoforms. No differences were observed between the pathologic groups. In conclusion, a coordinated increment in the expression of the TR isoforms was observed in both DCM and IHD by multiplex competitive RT-PCR. The observed changes could represent a compensatory mechanism to myocardial failure or to locally altered thyroid hormone action.

  4. On the Existence of Optimal Taxes for Network Congestion Games with Heterogeneous Users

    NASA Astrophysics Data System (ADS)

    Fotakis, Dimitris; Karakostas, George; Kolliopoulos, Stavros G.

    We consider network congestion games in which a finite number of non-cooperative users select paths. The aim is to mitigate the inefficiency caused by the selfish users by introducing taxes on the network edges. A tax vector is strongly (weakly)-optimal if all (at least one of) the equilibria in the resulting game minimize(s) the total latency. The issue of designing optimal tax vectors for selfish routing games has been studied extensively in the literature. We study for the first time taxation for networks with atomic users which have unsplittable traffic demands and are heterogeneous, i.e., have different sensitivities to taxes. On the positive side, we show the existence of weakly-optimal taxes for single-source network games. On the negative side, we show that the cases of homogeneous and heterogeneous users differ sharply as far as the existence of strongly-optimal taxes is concerned: there are parallel-link games with linear latencies and heterogeneous users that do not admit strongly-optimal taxes.

  5. Transcatheter Ovarian Vein Embolization Using Coils for the Treatment of Pelvic Congestion Syndrome

    SciTech Connect

    Kwon, Se Hwan; Oh, Joo Hyeong Ko, Kyung Ran; Park, Ho Chul; Huh, Joo Yup

    2007-07-15

    Purpose. To evaluate the therapeutic effectiveness of ovarian vein embolization using coils for pelvic congestion syndrome (PCS), a common cause of chronic pelvic pain in multiparous women. Methods. Between November 1998 and June 2005, 67 patients were diagnosed with PCS and underwent ovarian vein coil embolization. Through medical records and telephone interviews, the pre-embolization pain level and post-embolization pain control were assessed. In addition, in those cases where pain persisted after embolization or where patients were dissatisfied with the procedure, additional treatments and subsequent changes in pain scores were also analyzed. Evaluation after coil embolization was performed within 3-6 months (n = 3), 6 months to 1 year (n 7), 1-2 years (n = 13), 2-3 years (n = 7), 3-4 years (n = 7), 4-5 years (n 13), or 5-6 years (n = 17). Results. Among a total of 67 patients, 82% (55/67) experienced pain reduction after coil embolization, were satisfied with the procedure, and did not pursue any further treatment. Twelve patients (18%, 12/67) responded that their pain level had not changed, or had become more severe. Among them, 9 patients were treated surgically and the remaining 3 patients remained under continuous drug therapy. Conclusion. Ovarian vein embolization using coils is a safe and effective therapeutic method for treatment of PCS. It is thought that surgical treatment should be considered in cases where embolization proves ineffective.

  6. The Performance of Short-Term Heart Rate Variability in the Detection of Congestive Heart Failure

    PubMed Central

    Barros, Allan Kardec; Ohnishi, Noboru

    2016-01-01

    Congestive heart failure (CHF) is a cardiac disease associated with the decreasing capacity of the cardiac output. It has been shown that the CHF is the main cause of the cardiac death around the world. Some works proposed to discriminate CHF subjects from healthy subjects using either electrocardiogram (ECG) or heart rate variability (HRV) from long-term recordings. In this work, we propose an alternative framework to discriminate CHF from healthy subjects by using HRV short-term intervals based on 256 RR continuous samples. Our framework uses a matching pursuit algorithm based on Gabor functions. From the selected Gabor functions, we derived a set of features that are inputted into a hybrid framework which uses a genetic algorithm and k-nearest neighbour classifier to select a subset of features that has the best classification performance. The performance of the framework is analyzed using both Fantasia and CHF database from Physionet archives which are, respectively, composed of 40 healthy volunteers and 29 subjects. From a set of nonstandard 16 features, the proposed framework reaches an overall accuracy of 100% with five features. Our results suggest that the application of hybrid frameworks whose classifier algorithms are based on genetic algorithms has outperformed well-known classifier methods. PMID:27891509

  7. Prevalence of anemia in a Hispanic population with decompensated congestive heart failure.

    PubMed

    Del Río-Santiago, Valentín; Santiago-Trinidad, Ricardo; Espinell-González, Nelson; Valentín-Nieves, Julio; Giugliano, Robert P; Rodriguez-Ospina, Luis; Vicenty-Rivera, Sonia

    2011-01-01

    Anemia in patients with heart failure (HF is a frequent event, commonly associated with worse prognosis. Despite the high incidence and adverse outcomes associated with anemia no studies have been conducted amongst Hispanics with HF. The study aims to determine the prevalence, predictors and outcomes of anemia in Hispanics admitted to Veteran Affairs Caribbean Healthcare System with diagnosis of Decompensated Congestive Heart Failure (D-CHF). Retrospective review of 617 patient medical charts that had been previously discharged with a diagnosis of HF as per International Classification of Diseases-9 code. The clinical, demographic, laboratory and echocardiographic data was assessed for a total of 148 male patient electronic medical records that met the study inclusion criteria. The re-hospitalization and mortality rates were determined from the admission date until April 2010. The burden of anemia with HF is substantial, with anemia present in 68.2% of patients. Anemia was associated with hypoalbuminemia, higher New York Heart Association classification, elevated pro-BNP level at discharge, renal insufficiency and diastolic dysfunction, all of which demonstrated statistical significance. Anemia had 2.18 and 2.95 times likelihood of any-cause mortality (p = 0.003) and cardiovascular deaths (p = 0.02) when compared with HF patients without anemia. Anemia is a very frequent and serious finding in patients with D-CHF. The study reveals a higher prevalence of anemia in HF patients among Hispanics in comparison with formerly reported studies covering non-Hispanic populations.

  8. Limb congestion enhances the synchronization of sympathetic outflow with muscle contraction

    NASA Technical Reports Server (NTRS)

    Mostoufi-Moab, S.; Herr, M. D.; Silber, D. H.; Gray, K. S.; Leuenberger, U. A.; Sinoway, L. I.

    2000-01-01

    In this report, we examined if the synchronization of muscle sympathetic nerve activity (MSNA) with muscle contraction is enhanced by limb congestion. To explore this relationship, we applied signal-averaging techniques to the MSNA signal obtained during short bouts of forearm contraction (2-s contraction/3-s rest cycle) at 40% maximal voluntary contraction for 5 min. We performed this analysis before and after forearm venous congestion; an intervention that augments the autonomic response to sustained static muscle contractions via a local effect on muscle afferents. There was an increased percentage of the MSNA noted during second 2 of the 5-s contraction/rest cycles. The percentage of total MSNA seen during this particular second increased from minute 1 to 5 of contraction and was increased further by limb congestion (control minute 1 = 25.6 +/- 2.0%, minute 5 = 32.8 +/- 2.2%; limb congestion minute 1 = 29.3 +/- 2.1%, minute 5 = 37.8 +/- 3.9%; exercise main effect <0.005; limb congestion main effect P = 0.054). These changes in the distribution of signal-averaged MSNA were seen despite the fact that the mean number of sympathetic discharges did not increase over baseline. We conclude that synchronization of contraction and MSNA is seen during short repetitive bouts of handgrip. The sensitizing effect of contraction time and limb congestion are apparently due to feedback from muscle afferents within the exercising muscle.

  9. How Travel Demand Affects Detection of Non-Recurrent Traffic Congestion on Urban Road Networks

    NASA Astrophysics Data System (ADS)

    Anbaroglu, B.; Heydecker, B.; Cheng, T.

    2016-06-01

    Occurrence of non-recurrent traffic congestion hinders the economic activity of a city, as travellers could miss appointments or be late for work or important meetings. Similarly, for shippers, unexpected delays may disrupt just-in-time delivery and manufacturing processes, which could lose them payment. Consequently, research on non-recurrent congestion detection on urban road networks has recently gained attention. By analysing large amounts of traffic data collected on a daily basis, traffic operation centres can improve their methods to detect non-recurrent congestion rapidly and then revise their existing plans to mitigate its effects. Space-time clusters of high link journey time estimates correspond to non-recurrent congestion events. Existing research, however, has not considered the effect of travel demand on the effectiveness of non-recurrent congestion detection methods. Therefore, this paper investigates how travel demand affects detection of non-recurrent traffic congestion detection on urban road networks. Travel demand has been classified into three categories as low, normal and high. The experiments are carried out on London's urban road network, and the results demonstrate the necessity to adjust the relative importance of the component evaluation criteria depending on the travel demand level.

  10. Spatial-Temporal Congestion Identification Based on Time Series Similarity Considering Missing Data.

    PubMed

    Qi, Hongsheng; Liu, Meiqi; Wang, Dianhai; Chen, Mengwei

    2016-01-01

    Traffic congestion varies spatially and temporally. The observation of the formation, propagation and dispersion of network traffic congestion can lead to insights about the network performance, the bottleneck dynamics etc. While many researchers use the traffic flow data to reconstruct the congestion profile, the data missing problem is bypassed. Current methods either omit the missing data or supplement the missing part by average etc. Great error may be introduced during these processes. Rather than simply discarding the missing data, this research regards the data missing event as a result of either the severe congestion which prevent the floating vehicle from entering the congested area, or a type of feature of the resulting traffic flow time series. Hence a new traffic flow operational index time series similarity measurement is expected to be established as a basis of identifying the dynamic network bottleneck. The method first measures the traffic flow operational similarity between pairs of neighboring links, and then the similarity results are used to cluster the spatial-temporal congestion. In order to get the similarity under missing data condition, the measurement is implemented in a two-stage manner: firstly the so called first order similarity is calculated given that the traffic flow variables are bounded both upside and downside; then the first order similarity is aggregated to generate the second order similarity as the output. We implement the method on part of the real-world road network; the results generated are not only consistent with empirical observation, but also provide useful insights.

  11. Does rush hour see a rush of emotions? Driver mood in conditions likely to exhibit congestion.

    PubMed

    Morris, Eric A; Hirsch, Jana A

    2016-09-01

    Polls show that a large portion of the public considers traffic congestion to be a problem and believes a number of policy interventions would ameliorate it. However, most of the public rejects new taxes and fees to fund these improvements. This may be because of a disconnect between the public's stated antipathy towards congestion and the recalled emotional costs congestion imposes. To explore this, we use a large and representative sample drawn from the American Time Use Survey to examine how drivers experience four emotions (happiness, sadness, stress, and fatigue), plus a constructed composite mood variable, when they travel in peak periods, in large cities, in city centers, and in combinations of these. We also explore the interactions between these indicators and trip duration. We find evidence that drivers in the largest cities at the very peak of rush hour (5:00pm-6:00pm) are in a less positive mood, presumably because of congestion. However, this effect, though significant, is small, and we find no significant results using broader definitions of the peak period. In all, our findings suggest that congestion's impact on drivers as a group is quite limited. This may help explain why the public's attitude toward painful financial trade-offs to address congestion is lukewarm.

  12. Limb congestion enhances the synchronization of sympathetic outflow with muscle contraction

    NASA Technical Reports Server (NTRS)

    Mostoufi-Moab, S.; Herr, M. D.; Silber, D. H.; Gray, K. S.; Leuenberger, U. A.; Sinoway, L. I.

    2000-01-01

    In this report, we examined if the synchronization of muscle sympathetic nerve activity (MSNA) with muscle contraction is enhanced by limb congestion. To explore this relationship, we applied signal-averaging techniques to the MSNA signal obtained during short bouts of forearm contraction (2-s contraction/3-s rest cycle) at 40% maximal voluntary contraction for 5 min. We performed this analysis before and after forearm venous congestion; an intervention that augments the autonomic response to sustained static muscle contractions via a local effect on muscle afferents. There was an increased percentage of the MSNA noted during second 2 of the 5-s contraction/rest cycles. The percentage of total MSNA seen during this particular second increased from minute 1 to 5 of contraction and was increased further by limb congestion (control minute 1 = 25.6 +/- 2.0%, minute 5 = 32.8 +/- 2.2%; limb congestion minute 1 = 29.3 +/- 2.1%, minute 5 = 37.8 +/- 3.9%; exercise main effect <0.005; limb congestion main effect P = 0.054). These changes in the distribution of signal-averaged MSNA were seen despite the fact that the mean number of sympathetic discharges did not increase over baseline. We conclude that synchronization of contraction and MSNA is seen during short repetitive bouts of handgrip. The sensitizing effect of contraction time and limb congestion are apparently due to feedback from muscle afferents within the exercising muscle.

  13. Dynamically reconfigurable router for NoC congestion reduction

    NASA Astrophysics Data System (ADS)

    Rosales, Juan E.; Tobajas, Félix; de Armas, Valentín; Mori, José A.; Sarmiento, Roberto

    2011-05-01

    Multiprocessor System-on-Chip (MPSoCs) are emerging as one of the technologies providing a way to support the growing design complexity of embedded systems including several types of cores. The interconnection among cores of a MPSoC is proposed to be provided by Networks-on-Chip (NoC). In real applications it is usual to find different interconnection needs amongst cores, so distinct bandwidth is needed in each node of a NoC. Since larger FIFOs in NoC routers provide larger throughputs and smaller latencies, depths are usually sized for the worst case, compromising not only the routing area, but power consumption. In this paper, a reconfigurable router with a dynamic sharing mechanism of buffers at the input channels is proposed to reduce congestion in the network. In this situation, a channel may dynamically lend or borrow some non-used buffer units to or from neighboring channels, in accordance to the connection rates. The proposed reconfigurable router architecture was embedded in the Hermes NoC. The main advantages of the Hermes are its small size and modular design. This, as well as the open source approach, have lead to the selection of this NoC. The basic element of Hermes is a router with five bi-directional ports employing an XY routing algorithm. FIFO buffering is present only at the input channel, with all channels having the same buffer depth defined at design time. The proposed reconfigurable router has been coded in VHDL at RTL level from the adaptation of the Hermes router to fit into the proposed scheme. Results obtained from the simulation of the router under scenarios with different traffic characteristics and percentage of shared buffer, show that mean latency can be reduced up to a 30% in comparison to the original router.

  14. Does Thiazolidinedione therapy exacerbate fluid retention in congestive heart failure?

    PubMed

    Goltsman, Ilia; Khoury, Emad E; Winaver, Joseph; Abassi, Zaid

    2016-12-01

    The ever-growing global burden of congestive heart failure (CHF) and type 2 diabetes mellitus (T2DM) as well as their co-existence necessitate that anti-diabetic pharmacotherapy will modulate the cardiovascular risk inherent to T2DM while complying with the accompanying restrictions imposed by CHF. The thiazolidinedione (TZD) family of peroxisome proliferator-activated receptor γ (PPARγ) agonists initially provided a promising therapeutic option in T2DM owing to anti-diabetic efficacy combined with pleiotropic beneficial cardiovascular effects. However, the utility of TZDs in T2DM has declined in the past decade, largely due to concomitant adverse effects of fluid retention and edema formation attributed to salt-retaining effects of PPARγ activation on the nephron. Presumably, the latter effects are potentially deleterious in the context of pre-existing fluid retention in CHF. However, despite a considerable body of evidence on mechanisms responsible for TZD-induced fluid retention suggesting that this class of drugs is rightfully prohibited from use in CHF patients, there is a paucity of experimental and clinical studies that investigate the effects of TZDs on salt and water homeostasis in the CHF setting. In an attempt to elucidate whether TZDs actually exacerbate the pre-existing fluid retention in CHF, our review summarizes the pathophysiology of fluid retention in CHF. Moreover, we thoroughly review the available data on TZD-induced fluid retention and proposed mechanisms in animals and patients. Finally, we will present recent studies challenging the common notion that TZDs worsen renal salt and water retention in CHF. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. A New TCP Congestion Control Supporting RTT-Fairness

    NASA Astrophysics Data System (ADS)

    Ogura, Kazumine; Nemoto, Yohei; Su, Zhou; Katto, Jiro

    This paper focuses on RTT-fairness of multiple TCP flows over the Internet, and proposes a new TCP congestion control named “HRF (Hybrid RTT-Fair)-TCP”. Today, it is a serious problem that the flows having smaller RTT utilize more bandwidth than others when multiple flows having different RTT values compete in the same network. This means that a user with longer RTT may not be able to obtain sufficient bandwidth by the current methods. This RTT fairness issue has been discussed in many TCP papers. An example is CR (Constant Rate) algorithm, which achieves RTT-fairness by multiplying the square of RTT value in its window increment phase against TCP-Reno. However, the method halves its windows size same as TCP-Reno when a packet loss is detected. This makes worse its efficiency in certain network cases. On the other hand, recent proposed TCP versions essentially require throughput efficiency and TCP-friendliness with TCP-Reno. Therefore, we try to keep these advantages in our TCP design in addition to RTT-fairness. In this paper, we make intuitive analytical models in which we separate resource utilization processes into two cases: utilization of bottleneck link capacity and that of buffer space at the bottleneck link router. These models take into account three characteristic algorithms (Reno, Constant Rate, Constant Increase) in window increment phase where a sender receives an acknowledgement successfully. Their validity is proved by both simulations and implementations. From these analyses, we propose HRF-TCP which switches two modes according to observed RTT values and achieves RTT fairness. Experiments are carried out to validate the proposed method. Finally, HRF-TCP outperforms conventional methods in RTT-fairness, efficiency and friendliness with TCP-Reno.

  16. Effects of bucindolol on neurohormonal activation in congestive heart failure

    SciTech Connect

    Eichhorn, E.J.; McGhie, A.L.; Bedotto, J.B.; Corbett, J.R.; Malloy, C.R.; Hatfield, B.A.; Deitchman, D.; Willard, J.E.; Grayburn, P.A. )

    1991-01-01

    To examine the effects of beta-adrenergic blockade on neurohormonal activation in patients with congestive heart failure, 15 men had assessments of hemodynamics and supine peripheral renin and norepinephrine levels before and after 3 months of oral therapy with bucindolol, a nonselective beta antagonist. At baseline, plasma renin activity did not correlate with any hemodynamic parameter. However, norepinephrine levels had a weak correlation with left ventricular end-diastolic pressure (r = 0.74, p less than 0.01), stroke volume index (r = 0.61, p less than 0.02) and pulmonary vascular resistance (r = 0.54, p less than 0.05). Plasma renin decreased with bucindolol therapy, from 11.6 +/- 13.4 to 4.3 +/- 4.1 ng/ml/hour (mean +/- standard deviation; p less than 0.05), whereas plasma norepinephrine was unchanged, from 403 +/- 231 to 408 +/- 217 pg/ml. A wide diversity of the norepinephrine response to bucindolol was observed with reduction of levels in some patients and elevation in others. Although plasma norepinephrine did not decrease, heart rate tended to decrease (from 82 +/- 20 vs 73 +/- 11 min-1, p = 0.059) with beta-adrenergic blockade, suggesting neurohormonal antagonism at the receptor level. No changes in I-123 metaiodobenzylguanidine uptake occurred after bucindolol therapy, suggesting unchanged adrenergic uptake of norepinephrine with beta-blocker therapy. Despite reductions in plasma renin activity and the presence of beta blockade, the response of renin or norepinephrine levels to long-term bucindolol therapy did not predict which patients had improved in hemodynamic status (chi-square = 0.37 for renin, 0.82 for norepinephrine).

  17. Pneumoconiosis increases the risk of congestive heart failure

    PubMed Central

    Yen, Chia-Ming; Lin, Cheng-Li; Lin, Ming-Chia; Chen, Huei-Yong; Lu, Nan-Han; Kao, Chia-Hung

    2016-01-01

    Abstract The purpose of the study was to determine the relationship between pneumoconiosis and congestive heart failure (CHF). We collected data from the National Health Insurance Research Database in Taiwan. The study sample comprised 8923 patients with pneumoconiosis and 35,692 nonpneumoconiosis controls enrolled from 2000 to 2011. Patients were followed up until the end of 2011 to evaluate the incidence of CHF. The risk of CHF was analyzed using Cox proportional hazard regression models, and the analysis accounted for factors such as sex, age, comorbidities, and air pollutants (μg/m3). The overall incidence of CHF was higher in the pneumoconiosis cohort (15.7 per 1000 person-y) than in the nonpneumoconiosis cohort (11.2 per 1000 person-y), with a crude hazard ratio (HR) of 1.40 (P < 0.001). The HR for CHF was 1.38-fold greater in the pneumoconiosis cohort than in the nonpneumoconiosis cohort (P < 0.001) after the model was adjusted for age, sex, various comorbidities, and air pollutants (μg/m3). The relative risk for CHF in the sex-specific pneumoconiosis cohort compared with the nonpneumoconiosis cohort was significant for men (adjusted HR = 1.40, 95% confidence interval = 1.21–1.62, P < 0.001). The incidence density rates of CHF increased with age; pneumoconiosis patients had a higher relative risk of CHF for all age group. Patients with pneumoconiosis were at higher risk for developing CHF than patients in the nonpneumoconiosis cohort, particularly in cases with coexisting coronary artery disease, hypertension, and chronic obstructive pulmonary disease. PMID:27336897

  18. Decreasing body temperature predicts early rehospitalization in congestive heart failure.

    PubMed

    Ahmed, Amany; Aboshady, Ibrahim; Munir, Shahzeb M; Gondi, Sreedevi; Brewer, Alan; Gertz, S David; Lai, Dejian; Shaik, Naushad A; Shankar, K J; Deswal, Anita; Casscells, S Ward

    2008-08-01

    In congestive heart failure (CHF), a low body temperature at hospital admission predicts in-hospital mortality. We hypothesized that a postdischarge reduction in body temperature predicts early CHF rehospitalization and death. We reviewed the records of 198 patients discharged after CHF hospitalization. We categorized the patients as hypothermic or normothermic (cutoff point, 36.3 degrees C/97.4 degrees F) according to body temperature at discharge. We classified the 2 groups according to the direction of temperature change between discharge and the first follow-up visit: normothermic/non-decreasing temperature (N+), normothermic/decreasing temperature (N-), hypothermic/non-decreasing temperature (H+), and hypothermic/decreasing temperature (H-). Ninety-three patients (47%) had decreasing temperatures, and 105 patients (53%) had non-decreasing temperatures. Kaplan-Meier analysis revealed a significant intergroup difference in survival (P = .01) and rehospitalization time (P = .005). On logistic regression, a decreasing temperature was significantly associated with rehospitalization within 180 days (odds ratio, 4.01; 95% confidence interval, 1.63-10.02; P = .003). On Cox regression, the hazard ratios for death were 3.19 (P = .07), 6.49 (P = .004), and 5.17 (P = .07), for the N-, H+, and H- groups, respectively, versus the N+ group. For rehospitalization time, the hazard ratios were 7.02 (P = .01), 4.24 (P = .08), and 13.43 (P = .005) for the N-, H+, and H- groups, respectively, versus the N+ group. Decreasing body temperatures can predict readmission, decreased time to rehospitalization, and (in combination with hypothermia) decreased survival.

  19. Sodium and water balance in chronic congestive heart failure.

    PubMed Central

    Cody, R J; Covit, A B; Schaer, G L; Laragh, J H; Sealey, J E; Feldschuh, J

    1986-01-01

    As the characteristics of sodium and water balance in heart failure remain undefined, we evaluated the hemodynamic, metabolic, and hormonal effects of balanced sodium intake in 10 patients with chronic congestive heart failure. We discontinued diuretics to avoid their confounding influence, and all patients received 1 wk of 10 meq and 100 meq balanced sodium intake and controlled free water. Comparing sodium intake of 10 with 100 meq, the following observations were made. There was weight gain (2.0 kg) and increased sodium excretion (11 +/- 3 to 63 +/- 15 meq/24 h), unaccompanied by increase of blood volume. Both renin-angiotensin system and sympathetic nervous system activity were greater during the 10 meq diet, and suppressed with the 100 meq sodium diet. For both diets, plasma renin and urinary aldosterone excretion were correlated with urinary sodium excretion (r = -0.768, r = -0.726, respectively; P less than 0.005). Systemic hemodynamics were minimally changed with increased sodium intake. However, reversal of vasoconstriction by captopril during the 10 meq diet, and its ineffectiveness during the 100 meq diet, indicated a renin-dependent mechanism in the former, and a renin-independent mechanism in the latter diet. There were two subgroups of response to the 100 meq diet: one group (n = 5) achieved neutral balance, while the second (n = 5) avidly retained sodium and water. Renin-angiotensin system activity was significantly higher in the latter group, and the mechanism for differences in sodium excretion for the subgroups could not be identified by blood volume or hemodynamic parameters. Orthostatic hypotension during tilt was greater during the 10 meq sodium diet, and in all cases, related to ineffective hemodynamic and hormonal compensatory responses. PMID:3517066

  20. An intervention for VA patients with congestive heart failure.

    PubMed

    Copeland, Laurel A; Berg, Gregory D; Johnson, Donna M; Bauer, Richard L

    2010-03-01

    To assess the effect of a telephone intervention to improve quality of life among patients with congestive heart failure (CHF). Prospective randomized study. Single-site recruitment of 458 patients using Veterans Health Administration care into a randomized controlled trial with a 1-year preintervention data collection period and a 1-year intervention and follow-up period. To compensate for imbalanced study groups, propensity scores were included in adjusted models of quality of life, satisfaction with care, inpatient utilization, survival, and costs of care. Patients aged 45 to 95 years participated in the study; 22% were of Hispanic race/ethnicity, and 7% were African American. All but 5 were male, consistent with the older population among veterans. At baseline, 40% were in Goldman Specific Activity Scale class I, 42% were in class III, 6% were in class II or IV, and 12% were unclassified. Patients scored a mean (SD) of 14 (1.5) points below the norm on the physical component score. After the yearlong intervention, no differences in clinical outcomes were noted between the intervention group and the control group. The CHF-related costs were higher for the intervention group, as were overall costs that included the cost of the intervention. Intervention group patients reported better compliance with weight monitoring and exercise recommendations. A risk-stratified intervention for patients with CHF resulted in potential behavioral improvements but no survival benefit. A high-cost high-intensity intervention may be required to improve survival for patients with CHF. Inclusion of the costs of interventions is recommended for future researchers.

  1. Outcomes for older men and women with congestive heart failure.

    PubMed

    Burns, R B; McCarthy, E P; Moskowitz, M A; Ash, A; Kane, R L; Finch, M

    1997-03-01

    To describe and compare outcomes for men and women discharged alive following a hospitalization for congestive heart failure (CHF). Prospective cohort study. A total of 519 patients, aged > or = 65, who were discharged alive after a hospitalization for CHF (DRG = 127). Outcomes (Activities of Daily Living (ADLs), shortness of breath when walking, perceived health, living situation, rehospitalization, and mortality) were measured at 3 times (6 weeks, 6 months, and 1 year) post-discharge. The 205 men were, on average, younger (77 +/- 7 vs 80 +/- 8, P < .001), wealthier (46% vs 21% earned > or = $10,000, P < .001), and more often married (50% vs 19%, P < .001). Men were more likely than women to have a previous history of CHF (71% vs 63%, P = .052). Men also had higher 1-year mortality than women (48% vs 35%, P = .009), even after adjusting for age, comorbidity, physiological severity (APACHE II APS and RAND discharge instability), radiological evidence of CHF, prior ADLs, walking ability, living situation, and perceived health. Men and women survivors at 1-year had similar and substantial impairment for all non-fatal outcomes considered (all P values > or = .489). Their adjusted mean ADL scores were consistent with complete dependence on one essential activity (range 0-6 dependencies); 35% were short of breath walking less than 1 block; 62% had fair or poor perceived health; 32% received some formal care; and 46% were rehospitalized within 1 year of discharge. Men with CHF have a higher mortality than women with CHF. Men and women who survive have similar and substantial impairment for all non-fatal outcomes (ADLs, shortness of breath upon walking, perceived health, living situation, and rehospitalization).

  2. Anaemia and congestive heart failure early post-renal transplantation.

    PubMed

    Borrows, Richard; Loucaidou, Marina; Chusney, Gary; Borrows, Sarah; Tromp, Jen Van; Cairns, Tom; Griffith, Megan; Hakim, Nadey; McLean, Adam; Palmer, Andrew; Papalois, Vassilios; Taube, David

    2008-05-01

    Anaemia is common following renal transplantation and is associated with the development of congestive heart failure (CHF). However the prevalence of anaemia in the first year following transplantation and the association between anaemia occurring early and the development of CHF have been understudied. In this study, 132 incident patients undergoing tacrolimus and mycophenolate mofetil-based renal transplantation were studied for the prevalence of, and risk factors for, anaemia and CHF in the early period post transplantation. Anaemia occurred in 94.5% and 53.1% of patients at 1 week and 12 months, respectively, and was associated with allograft dysfunction, hypoalbuminaemia, higher mycophenolic acid (MPA) levels, bacterial infection and hypoalbuminaemia. The association with hypoalbuminaemia may reflect the presence of chronic inflammation post-transplantation. Of patients displaying haemoglobin <11 g/dl, 41.1% and 29.4% were treated with erythropoiesis stimulating agents (ESAs) at 1 and 12 months respectively. CHF developed in 26 patients beyond 1 month post-transplantation, with echocardiographic left ventricular systolic function preserved in all but one. CHF was associated with anaemia and lower haemoglobin, allograft dysfunction, duration of dialysis and left ventricular hypertrophy on echocardiography prior to transplantation, suggesting the aetiology of CHF may involve the interplay of diastolic cardiac dysfunction, pre-load mismatch and after-load mismatch. Modification of risk factors may improve anaemia management post transplantation. Reducing the prevalence of anaemia may in turn reduce the incidence of CHF-these observations support the need for clinical trials to determine how anaemia management may impact CHF incidence.

  3. Evaluation of the public health impacts of traffic congestion: a health risk assessment

    PubMed Central

    2010-01-01

    Background Traffic congestion is a significant issue in urban areas in the United States and around the world. Previous analyses have estimated the economic costs of congestion, related to fuel and time wasted, but few have quantified the public health impacts or determined how these impacts compare in magnitude to the economic costs. Moreover, the relative magnitudes of economic and public health impacts of congestion would be expected to vary significantly across urban areas, as a function of road infrastructure, population density, and atmospheric conditions influencing pollutant formation, but this variability has not been explored. Methods In this study, we evaluate the public health impacts of ambient exposures to fine particulate matter (PM2.5) concentrations associated with a business-as-usual scenario of predicted traffic congestion. We evaluate 83 individual urban areas using traffic demand models to estimate the degree of congestion in each area from 2000 to 2030. We link traffic volume and speed data with the MOBILE6 model to characterize emissions of PM2.5 and particle precursors attributable to congestion, and we use a source-receptor matrix to evaluate the impact of these emissions on ambient PM2.5 concentrations. Marginal concentration changes are related to a concentration-response function for mortality, with a value of statistical life approach used to monetize the impacts. Results We estimate that the monetized value of PM2.5-related mortality attributable to congestion in these 83 cities in 2000 was approximately $31 billion (2007 dollars), as compared with a value of time and fuel wasted of $60 billion. In future years, the economic impacts grow (to over $100 billion in 2030) while the public health impacts decrease to $13 billion in 2020 before increasing to $17 billion in 2030, given increasing population and congestion but lower emissions per vehicle. Across cities and years, the public health impacts range from more than an order of

  4. Relief and Recurrence of Congestion During and After Hospitalization for Acute Heart Failure: Insights From Diuretic Optimization Strategy Evaluation in Acute Decompensated Heart Failure (DOSE-AHF) and Cardiorenal Rescue Study in Acute Decompensated Heart Failure (CARESS-HF).

    PubMed

    Lala, Anuradha; McNulty, Steven E; Mentz, Robert J; Dunlay, Shannon M; Vader, Justin M; AbouEzzeddine, Omar F; DeVore, Adam D; Khazanie, Prateeti; Redfield, Margaret M; Goldsmith, Steven R; Bart, Bradley A; Anstrom, Kevin J; Felker, G Michael; Hernandez, Adrian F; Stevenson, Lynne W

    2015-07-01

    Congestion is the most frequent cause for hospitalization in acute decompensated heart failure. Although decongestion is a major goal of acute therapy, it is unclear how the clinical components of congestion (eg, peripheral edema, orthopnea) contribute to outcomes after discharge or how well decongestion is maintained. A post hoc analysis was performed of 496 patients enrolled in the Diuretic Optimization Strategy Evaluation in Acute Decompensated Heart Failure (DOSE-AHF) and Cardiorenal Rescue Study in Acute Decompensated Heart Failure (CARRESS-HF) trials during hospitalization with acute decompensated heart failure and clinical congestion. A simple orthodema congestion score was generated based on symptoms of orthopnea (≥2 pillows=2 points, <2 pillows=0 points) and peripheral edema (trace=0 points, moderate=1 point, severe=2 points) at baseline, discharge, and 60-day follow-up. Orthodema scores were classified as absent (score of 0), low-grade (score of 1-2), and high-grade (score of 3-4), and the association with death, rehospitalization, or unscheduled medical visits through 60 days was assessed. At baseline, 65% of patients had high-grade orthodema and 35% had low-grade orthodema. At discharge, 52% patients were free from orthodema at discharge (score=0) and these patients had lower 60-day rates of death, rehospitalization, or unscheduled visits (50%) compared with those with low-grade or high-grade orthodema (52% and 68%, respectively; P=0.038). Of the patients without orthodema at discharge, 27% relapsed to low-grade orthodema and 38% to high-grade orthodema at 60-day follow-up. Increased severity of congestion by a simple orthodema assessment is associated with increased morbidity and mortality. Despite intent to relieve congestion, current therapy often fails to relieve orthodema during hospitalization or to prevent recurrence after discharge. URL: http://www.clinicaltrials.gov. Unique identifiers: NCT00608491, NCT00577135. © 2015 American Heart

  5. Bus-based park-and-ride system: a stochastic model on multimodal network with congestion pricing schemes

    NASA Astrophysics Data System (ADS)

    Liu, Zhiyuan; Meng, Qiang

    2014-05-01

    This paper focuses on modelling the network flow equilibrium problem on a multimodal transport network with bus-based park-and-ride (P&R) system and congestion pricing charges. The multimodal network has three travel modes: auto mode, transit mode and P&R mode. A continuously distributed value-of-time is assumed to convert toll charges and transit fares to time unit, and the users' route choice behaviour is assumed to follow the probit-based stochastic user equilibrium principle with elastic demand. These two assumptions have caused randomness to the users' generalised travel times on the multimodal network. A comprehensive network framework is first defined for the flow equilibrium problem with consideration of interactions between auto flows and transit (bus) flows. Then, a fixed-point model with unique solution is proposed for the equilibrium flows, which can be solved by a convergent cost averaging method. Finally, the proposed methodology is tested by a network example.

  6. Analysis of Aircraft Clusters to Measure Sector-Independent Airspace Congestion

    NASA Technical Reports Server (NTRS)

    Bilimoria, Karl D.; Lee, Hilda Q.

    2005-01-01

    The Distributed Air/Ground Traffic Management (DAG-TM) concept of operations* permits appropriately equipped aircraft to conduct Free Maneuvering operations. These independent aircraft have the freedom to optimize their trajectories in real time according to user preferences; however, they also take on the responsibility to separate themselves from other aircraft while conforming to any local Traffic Flow Management (TFM) constraints imposed by the air traffic service provider (ATSP). Examples of local-TFM constraints include temporal constraints such as a required time of arrival (RTA), as well as spatial constraints such as regions of convective weather, special use airspace, and congested airspace. Under current operations, congested airspace typically refers to a sector(s) that cannot accept additional aircraft due to controller workload limitations; hence Dynamic Density (a metric that is indicative of controller workload) can be used to quantify airspace congestion. However, for Free Maneuvering operations under DAG-TM, an additional metric is needed to quantify the airspace congestion problem from the perspective of independent aircraft. Such a metric would enable the ATSP to prevent independent aircraft from entering any local areas of congestion in which the flight deck based systems and procedures may not be able to ensure separation. This new metric, called Gaggle Density, offers the ATSP a mode of control to regulate normal operations and to ensure safety and stability during rare-normal or off-normal situations (e.g., system failures). It may be difficult to certify Free Maneuvering systems for unrestricted operations, but it may be easier to certify systems and procedures for specified levels of Gaggle Density that could be monitored by the ATSP, and maintained through relatively minor flow-rate (RTA type) restrictions. Since flight deck based separation assurance is airspace independent, the challenge is to measure congestion independent of sector

  7. Congestion and flow control in signaling system No. 7: Impacts of intelligent networks and new services

    SciTech Connect

    Zepf, J.; Rufa, G. )

    1994-04-01

    This paper focuses on the transient performance analysis of the congestion and flow control mechanisms in CCITT Signaling System No. 7 (SS7). Special attention is directed to the impacts of the introduction of intelligent services and new applications, e.g., Freephone, credit card services, user-to-user signaling, etc. In particular, we show that signaling traffic characteristics like signaling scenarios or signaling message length as well as end-to-end signaling capabilities have a significant influence on the congestion and flow control and, therefore, on the real-time signaling performance. One important result of our performance studies is that if, e.g., intelligent services are introduced, the SS7 congestion and flow control does not work correctly. To solve this problem, some reinvestigations into these mechanisms would be necessary. Therefore, some approaches, e.g., modification of the Signaling Connection Control Part (SCCP) congestion control, usage of the SCCP relay function, or a redesign of the MTP flow control procedures are discussed in order to guarantee the efficacy of the congestion and flow control mechanisms also in the future. 16 refs.

  8. On the Efficiency of the New York Independent System OperatorMarket for Transmission Congestion Contracts

    SciTech Connect

    Siddiqui, Afzal S.; Bartholomew, Emily S.; Marnay, Chris; Oren,Shmuel S.

    2003-04-01

    The physical nature of electricity generation and deliverycreates special problems for the design of efficient markets, notably theneed to manage delivery in real time and the volatile congestion andassociated costs that result. Proposals for the operation of thederegulated electricity industry tend towards one of two paradigms:centralized and decentralized. Transmission congestion management can beimplemented in the more centralized point-to-point approach, a in NewYork state, where derivative transmission congestion contracts (TCCs) aretraded, or in the more decentralized flowgate-based approach. While it iswidely accepted that theoretically TCCs have attractive properties ashedging instruments against congestion cost uncertainty, whetherefficient markets for them can be established in practice has beenquestioned. Based on an empirical analysis of publicly available datafrom years 2000 and 2001, it appears that New York TCCs providedmarketparticipants with a potentially effective hedge against volatilecongestion rents. However, the prices paid for TCCs systematicallydiverged from the resulting congestion rents for distant locations and athigh prices. The price paid for the hedge not being in line with thecongestion rents, i.e. unreasonably high risk premiums are being paid,suggests an inefficient market. The low liquidity of TCC markets and thedeviation of TCC feasibility requirements from actual energy flows arepossible explanations.

  9. Medicinal Leech Therapy for Glans Penis Congestion After Primary Bladder Exstrophy-Epispadias Repair in an Infant: A Case Report.

    PubMed

    Wagenheim, Gavin N; Au, Jason; Gargollo, Patricio C

    2016-01-01

    Many postoperative complications have been reported after repair of classic bladder exstrophy. We present a case of medicinal leech therapy for glans penis congestion following exstrophy repair in an infant. A 2-week-old male with classic bladder exstrophy underwent complete primary repair. On postoperative day 1, he developed rapidly worsening glans penis venous congestion. Medicinal leech therapy was instituted with antibiotics and blood transfusions to maintain a hematocrit >30%. After 24 hours, venous congestion improved and therapy was discontinued. The patient's remaining hospital course was uncomplicated. Medicinal leeches are an effective therapy to relieve glans penis venous congestion. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Administration of tolvaptan with reduction of loop diuretics ameliorates congestion with improving renal dysfunction in patients with congestive heart failure and renal dysfunction.

    PubMed

    Hanatani, Akihisa; Shibata, Atsushi; Kitada, Ryouko; Iwata, Shinichi; Matsumura, Yoshiki; Doi, Atsushi; Sugioka, Kenichi; Takagi, Masahiko; Yoshiyama, Minoru

    2017-03-01

    In patients with congestive heart failure and renal dysfunction, high dose of diuretics are necessary to improve congestion, which may progress to renal dysfunction. We examined the efficacy of tolvaptan with reduction of loop diuretics to improve renal function in patients with congestive heart failure and renal dysfunction. We conducted a multicenter, prospective, randomized study in 44 patients with congestive heart failure and renal dysfunction (serum creatinine concentration ≥1.1 mg/dl) treated with conventional diuretics. Patients were randomly divided into two groups: tolvaptan (15 mg) with a fixed dose of diuretics or with reducing to a half-dose of diuretics for 7-14 consecutive days. We examined the change of urine volume, body weight, serum creatinine and electrolyte concentrations in each group. Both groups demonstrated significant urine volume increase (724 ± 176 ml/day in the fixed-dose group and 736 ± 114 ml/day in the half-dose group) and body weight reduction (1.6 ± 1.5 kg and 1.6 ± 1.9 kg, respectively) from baseline, with no differences between the two groups. Serum creatinine concentration was significantly increased in the fixed-dose group (from 1.60 ± 0.47 to 1.74 ± 0.66 mg/dl, p = 0.03) and decreased in the half-dose group (from 1.98 ± 0.91 to 1.91 ± 0.97 mg/dl, p = 0.10). So the mean changes in serum creatinine concentration from baseline significantly differed between the two groups (0.14 ± 0.08 mg/dl in the fixed-dose group and -0.07 ± 0.19 mg/dl in the half-dose group, p = 0.006). The administration of tolvaptan with reduction of loop diuretics was clinically effective to ameliorate congestion with improving renal function in patients with congestive heart failure and renal dysfunction.

  11. Hearing the Veteran's Voice in Congestive Heart Failure Readmissions.

    PubMed

    Stevenson, Carl W; Pori, Daria; Payne, Kattie; Black, Mary; Taylor, Victoria E

    2015-01-01

    Our purpose was to examine congestive heart failure (CHF) readmissions from the veterans' perspective. The use of health care provider interventions, such as standardized education materials, home telehealth, and a CHF clinic, was able to reduce readmissions rates from 35% to 23%. Our objective was to use input from the veterans to fine-tune our efforts and achieve readmission rates for patients with CHF below the national average of 21%. We wanted to identify factors that result in CHF readmissions, including disease education, self-care management, and barriers to self-care. This study was directed toward answering two questions: 1. What is the veteran’s explanation for readmission? 2. According to the veteran, what are the barriers to following their treatment regimen? It was a rural 84-bed Veterans Health Administration hospital in the Western United States. Before this study, our efforts to reduce CHF readmissions were one-sided, all from the health care professionals' viewpoint. We wanted to hear what the veteran had to say; so, we interviewed 25 veterans. Four veterans were excluded due to issues with their consents. Ninety percent (n = 19/21) responded that they knew their CHF was worse by a change in their breathing (shortness of breath). They identified 48 signs/symptoms that indicated worsening CHF. Weight gain was noted as an indication of worsening CHF symptoms (n = 6/48) in 12.5% of the responses. Twenty-five percent (n = 12/48) of the veterans stated they recognized the early symptoms of worsening CHF. Thirty-eight percent (n = 8/21) of the veterans stated they had early symptoms of worsening CHF, but only two of them contacted their doctor. It is interesting to note that only 29% (n = 6/21) of the veterans recognized weight gain as a sign of worsening CHF and all of these veterans listed other symptoms (such as shortness of breath) along with weight gain. Weighing on a daily basis was practiced by only 30% of the group (n = 7/21); all but two of

  12. Surveying traffic congestion based on the concept of community structure of complex networks

    NASA Astrophysics Data System (ADS)

    Ma, Lili; Zhang, Zhanli; Li, Meng

    2016-07-01

    In this paper, taking the traffic of Beijing city as an instance, we study city traffic states, especially traffic congestion, based on the concept of network community structure. Concretely, using the floating car data (FCD) information of vehicles gained from the intelligent transport system (ITS) of the city, we construct a new traffic network model which is with floating cars as network nodes and time-varying. It shows that this traffic network has Gaussian degree distributions at different time points. Furthermore, compared with free traffic situations, our simulations show that the traffic network generally has more obvious community structures with larger values of network fitness for congested traffic situations, and through the GPSspg web page, we show that all of our results are consistent with the reality. Then, it indicates that network community structure should be an available way for investigating city traffic congestion problems.

  13. Biventricular pacing in congestive heart failure: a boost toward finer living.

    PubMed

    Luck, Jerry C; Wolbrette, Deborah L; Boehmer, John P; Ulsh, Paula J; Silber, David; Naccarelli, Gerald V

    2002-01-01

    With 550,000 new cases each year, congestive heart failure is a major medical problem. Several medical therapies, including digoxin, angiotensin-converting enzyme inhibitors, and beta-blockers, have reduced the number of re-hospitalizations and slowed the progression of congestive heart failure. Angiotensin-converting enzyme inhibitors, some beta-blockers, and the combination of hydralazine with nitrates have improved survival. Despite these benefits, medical therapy frequently fails to improve quality of life. Biventricular pacing has been introduced to resynchronize mechanical and electrical asynchrony frequently observed in patients with heart failure. The most recent pacing trials show an improvement in quality of life and functional class. Long-term data are needed to determine the effect of biventricular pacing on survival. The acute hemodynamic studies suggest that resynchronization pacing therapy may predict a positive long-term benefit for many patients with congestive heart failure.

  14. Traffic Cellular Automata Simulation of a Congested Round-About in Mauritius

    NASA Astrophysics Data System (ADS)

    Fowdur, S. C.; Rughooputh, S. D. D. V.

    In this paper a Traffic Cellular Automata (TCA) simulation of a highly congested round-about in Mauritius is performed. The simulations are performed using a multi-cell model that includes anticipation and probability randomization. The simulation model is first calibrated to match actual traffic count statistics taken at the round-about. The topology of the round-about is then modified and the TCA model is used to predict the impact on the congestion level of different changes made. The simulation results enable the assessment of the impact on the traffic density and travel time of the different modifications made. It has been found that the construction of a flyover bridge at the round-about will be the most convenient solution to alleviate congestion and improve the flux significantly.

  15. Congestion Control for TCP/AQM Networks using State Predictive Control

    NASA Astrophysics Data System (ADS)

    Azuma, Takehito; Fujita, Tsunetoshi; Fujita, Masayuki

    The purpose of this paper is to design congestion controllers for TCP/AQM networks using state predictive control and illustrate the effectiveness of designed congestion controllers via SIMULINK and the ns-2 simulator. Linearized models of TCP/AQM networks can be described as linear systems with an information delay simply. Using state predictive control, these linear systems with an information delay is equivalent to linear systems with no delays. Thus congestion controllers (AQM mechanisms) can be designed using the linear control theory. In this paper, LQ control with an observer is adopted for linear systems with no delays which describe linearized systems of TCP/AQM networks. Finally the designed state predictive controllers using LQ control with an observer is implemented and some simulation results are shown via SIMULINK and the ns-2 simulator.

  16. Inflammatory Biomarkers in Refractory Congestive Heart Failure Patients Treated with Peritoneal Dialysis.

    PubMed

    Kunin, Margarita; Carmon, Vered; Arad, Michael; Levin-Iaina, Nomy; Freimark, Dov; Holtzman, Eli J; Dinour, Dganit

    2015-01-01

    Proinflammatory cytokines play a pathogenic role in congestive heart failure. In this study, the effect of peritoneal dialysis treatment on inflammatory cytokines levels in refractory congestive heart failure patients was investigated. During the treatment, the patients reached a well-tolerated edema-free state and demonstrated significant improvement in NYHA functional class. Brain natriuretic peptide decreased significantly after 3 months of treatment and remained stable at 6 months. C-reactive protein, a plasma marker of inflammation, decreased significantly following the treatment. Circulating inflammatory cytokines TNF-α and IL-6 decreased significantly after 3 months of peritoneal dialysis treatment and remained low at 6 months. The reduction in circulating inflammatory cytokines levels may be partly responsible for the efficacy of peritoneal dialysis for refractory congestive heart failure.

  17. [Parallel pharmacological correction of myocardial dysfunction, cognitive and psychopathological disordres in patients with congestive heart failure].

    PubMed

    Dotsenko, N Ia; Boev, S S; Shekhunova, I A; Dedova, V O

    2014-01-01

    Was examined 92 patients with congestive heart failure III-IV FC with fraction of emission left ventricle < 45% against coronary artery disease. Patients of control group received basic therapy (according to recommendations of the Ukrainian society of cardiology), the 1 group--in addition received a preparation of Vazonat within 15 days intravenously in a dose of 1000 mg a day further are out-patient within 1 month on 250 mg 3 times per os; the 2 group--under the same scheme a preparation of Vazonat and a day tranquilizer of Adapto in a dose of 500 mg twice a day throughout all term of supervision. It is established that addition of Vazonat to basic treatment leads to additional effect concerning improvement of indicators cardio-hemodynamic, to improvement congestive functions. Joint appointment of preparations of Vazonat and Adaptol against basic treatment leads to more expressed improvement congestive functions, to progressive reduction of degree of trouble, depression.

  18. Emergency diagnosis of congestive heart failure: impact of signs and symptoms.

    PubMed

    Mueller, Christian; Frana, Barbara; Rodriguez, Daniel; Laule-Kilian, Kirsten; Perruchoud, André P

    2005-09-01

    The most useful features in the diagnosis of congestive heart failure (CHF) have been poorly investigated. To determine the utility of signs and symptoms in the diagnosis of CHF in the emergency department. Detailed clinical data were collected prospectively from 452 consecutive patients presenting with acute dyspnea to the emergency department. By using logistic regression analysis, significant predictors for the final discharge diagnosis of CHF (adjudicated after review of all patient records, including response to therapy) were assessed. In 217 of 452 patients (48%), CHF was the cause of acute dyspnea. Among symptoms, the OR for CHF was highest for weight gain (OR 3.6; 95% CI 1.9 to 7.0), nocturia (OR 2.4; 95% CI 1.6 to 3.7) and paroxysmal nocturnal dyspnea (OR 2.4; 95% CI 1.6 to 3.5), and lowest for fever (OR 0.36; 95% CI 0.22 to 0.56). Among signs, the OR was highest for elevated jugular venous pressure (OR 4.3; 95% CI 2.3 to 7.9), rales (OR 3.1; 95% CI 2.1 to 4.5), lower extremity edema (OR 2.8; 95% CI 1.9 to 4.3) and hepatojugular reflux (OR 2.7; 95% CI 1.4 to 5.2), and lowest for wheezing (OR 0.38; 95% CI 0.24 to 0.61). The overall sensitivity was low. The specificity was highest for elevated jugular venous pressure and hepatojugular reflux. Signs and symptoms are only moderately helpful in the diagnosis of CHF in patients with acute dyspnea. This emphasizes the need for additional diagnostic tools, such as echocardiography or B-type natriuretic peptide testing.

  19. Long-term outcome of patients with acromegaly and congestive heart failure.

    PubMed

    Bihan, Hélène; Espinosa, Consuelo; Valdes-Socin, Hernan; Salenave, Sylvie; Young, Jacques; Levasseur, Suzanne; Assayag, Patrick; Beckers, Albert; Chanson, Philippe

    2004-11-01

    Cardiovascular complications are a major cause of morbidity and mortality in patients with acromegaly. Normalization of GH secretion is associated with an improvement in structural and functional cardiac abnormalities. However, the long-term cardiac effects of treatment for acromegaly have not been studied in patients who have already developed chronic congestive heart failure (CHF). We reviewed the charts of 330 consecutive patients with acromegaly treated in two French and Belgian centers since 1985. Ten patients with both acromegaly and CHF (eight men, two women, mean age 49.7 yr) were studied retrospectively. One of them was excluded because CHF was due to severe aortic stenosis.CHF (New York Heart Association stages III-IV and echocardiography showing dilated hypokinetic cardiomyopathy with left ventricular systolic dysfunction and a left ventricular ejection fraction less than 45%) was diagnosed before, concomitantly, or after acromegaly in, respectively, two, five, and two patients. Three patients were referred with terminal heart failure requiring transplantation.One patient had transient CHF associated with a hypertensive crisis. The other eight patients had symptomatic chronic CHF. Control of GH hypersecretion failed, totally or partially, in three patients: one had a long-term survival, and the two others died at 1 and 5 yr. Good GH control was achieved in five patients: four of these are still alive 2-16 yr after diagnosis of CHF, their clinical status is stable or improved, and their quality of life is good. Overall, the 1- and 5-yr mortality (or transplantation) rates for patients with chronic symptomatic CHF were 25% (2 of 8 patients) and 37.5% (3 of 8 patients), respectively. In conclusion, less than 3% of acromegalic patients developed CHF in this study. Although effective treatment of acromegaly improved short-term cardiovascular status, its impact on long-term survival is questionable.

  20. Transitional Care for Patients With Congestive Heart Failure: A Systematic Review and Meta-Analysis

    PubMed Central

    Vedel, Isabelle; Khanassov, Vladimir

    2015-01-01

    PURPOSE We aimed to determine the impact of transitional care interventions (TCIs) on acute health service use by patients with congestive heart failure in primary care and to identify the most effective TCIs and their optimal duration. METHODS We conducted a systematic review and meta-analysis of randomized controlled trials, searching the Medline, PsycInfo, EMBASE, and Cochrane Library databases. We performed a meta-analysis to assess the impact of TCI on all-cause hospital readmissions and emergency department (ED) visits. We developed a taxonomy of TCIs based on intensity and assessed the methodologic quality of the trials. We calculated the relative risk (RR) and a 95% confidence interval for each outcome. We conducted a stratified analysis to identify the most effective TCIs and their optimal duration. RESULTS We identified 41 randomized controlled trials. TCIs significantly reduced risks of readmission and ED visits by 8% and 29%, respectively (relative risk = 0.92; 95% CI, 0.87–0.98; P = .006 and relative risk = 0.71; 95% CI, 0.51–0.98; P = .04). High-intensity TCIs (combining home visits with telephone followup, clinic visits, or both) reduced readmission risk regardless of the duration of follow-up. Moderate-intensity TCIs were efficacious if implemented for a longer duration (at least 6 months). In contrast, low-intensity TCIs, entailing only followup in outpatient clinics or telephone follow-up, were not efficacious. CONCLUSIONS Clinicians and managers who implement TCIs in primary care can incorporate these results with their own health care context to determine the optimal balance between intensity and duration of TCIs. High-intensity interventions seem to be the best option. Moderate-intensity interventions implemented for 6 months or longer may be another option. PMID:26553896

  1. Haemodynamic response to peripheral venous congestion in patients with unexplained recurrent syncope.

    PubMed

    Bellard, Elisabeth; Fortrat, Jacques-Olivier; Dupuis, Jean-Marc; Victor, Jacques; Lefthériotis, Georges

    2003-09-01

    In patients with recurrent unexplained syncope, exaggerated peripheral venous pooling and impaired circulatory adjustment is thought to contribute to the outcome of a head-up tilt (HUT) test. The present study investigated the role of leg volume changes during venous congestion in the haemodynamic response of patients with recurrent unexplained syncope and the ability to predict the outcome of a HUT test. Changes in calf volume (strain gauge plethysmography), heart rate and arterial blood pressure were recorded in 60 patients with history of unexplained syncope (without postural tachycardia symptom) during venous congestion provoked by pneumatic thigh cuffs while supine at rest and during the initial 10 min of a 45 min 70 degrees HUT test. Twenty-seven patients [age (mean+/-S.D.), 39+/-16 years] exhibited symptoms [HUT(+)] and 33 patients (45+/-14 years) were asymptomatic [HUT(-)]. During venous congestion, mean+/-S.E.M. calf volume increased in both groups [HUT(-), 4.5+/-0.2; HUT(+), 4.8+/-0.4 ml x 100 ml(-1), not significant), but significantly less during head-upright tilt [HUT(-), 3.3+/-0.2, P <0.01; HUT(+), 2.6+/-0.3 ml x 100 ml(-1), P <0.001] without differences between the groups. During venous congestion, arterial pressure increased significantly in asymptomatic HUT(-) patients, but not in the HUT(+) patients. Calf volume changes did not correlate with a symptomatic outcome to a 70 degrees HUT. The lack of exaggerated venous pooling during venous congestion and the inability of calf volume changes to predict a positive HUT suggest that excessive venous pooling does not contribute to the outcome of HUT. Attenuated changes in arterial pressure during venous congestion while supine suggest impaired adjustment of peripheral resistance to leg venous occlusion.

  2. Cardiac Dysfunction, Congestion and Loop Diuretics: their Relationship to Prognosis in Heart Failure.

    PubMed

    Pellicori, Pierpaolo; Cleland, John G F; Zhang, Jufen; Kallvikbacka-Bennett, Anna; Urbinati, Alessia; Shah, Parin; Kazmi, Syed; Clark, Andrew L

    2016-12-01

    Diuretics are the mainstay of treatment for congestion but concerns exist that they adversely affect prognosis. We explored whether the relationship between loop diuretic use and outcome is explained by the underlying severity of congestion amongst patients referred with suspected heart failure. Of 1190 patients, 712 had a left ventricular ejection fraction (LVEF) ≤50 %, 267 had LVEF >50 % with raised plasma NTproBNP (>400 ng/L) and 211 had LVEF >50 % with NTproBNP ≤400 ng/L; respectively, 72 %, 68 % and 37 % of these groups were treated with loop diuretics including 28 %, 29 % and 10 % in doses ≥80 mg furosemide equivalent/day. Compared to patients with cardiac dysfunction (either LVEF ≤50 % or NT-proBNP >400 ng/L) but not taking a loop diuretic, those taking a loop diuretic were older and had more clinical evidence of congestion, renal dysfunction, anaemia and hyponatraemia. During a median follow-up of 934 (IQR: 513-1425) days, 450 patients were hospitalized for HF or died. Patients prescribed loop diuretics had a worse outcome. However, in multi-variable models, clinical, echocardiographic (inferior vena cava diameter), and biochemical (NTproBNP) measures of congestion were strongly associated with an adverse outcome but not the use, or dose, of loop diuretics. Prescription of loop diuretics identifies patients with more advanced features of heart failure and congestion, which may account for their worse prognosis. Further research is needed to clarify the relationship between loop diuretic agents and outcome; imaging and biochemical measures of congestion might be better guides to diuretic dose than symptoms or clinical signs.

  3. Induction and relief of nasal congestion in ferrets infected with influenza virus.

    PubMed Central

    Chen, K. S.; Bharaj, S. S.; King, E. C.

    1995-01-01

    Susceptible ferrets intranasally infected with influenza virus consistently responded with maximal nasal secretion of virus, febrile reaction, and influx of inflammatory cells into nasal lumen on day 2 post infection (d.p.i.). Polymorphonuclear leucocytes were the earliest predominant cell, followed by monocytes/macrophages while lymphocytes were maintained as a minor population throughout the 7-day period. Nasal congestion level, continuously monitored by computer aided active anterior rhinomanometry, was reproducibly maximal at 2 d.p.i., diminished in intensity the next day and returned to the basal level within 7 d.p.i. Nasal congestion was effectively relieved by a single intranasal dose of 0.1% oxymetazoline or 0.2% phenylephrine, or a single intragastric administration of pseudoephedrine. Intranasal delivery of a single dose of 1% pyrilamine relieved nasal congestion while 0.8% ipratropium bromide and 30% cimetidine were ineffective. These results suggested that nasal congestion is regulated by alpha-adrenergic receptors in the mucosal vasculature or by H1 histamine receptor, but is unaffected by inhibitors of nasal secretion regulated by the cholinergic nervous system. The present study indicates that the infectious rhinitis ferret model provides a reproducible nasal congestion pattern that can be objectively measured by a refined active anterior rhinomanometric system. This labour intensive measurement, however, makes it difficult either to conduct a large population animal study or to use it for a rapid throughput screening of new drugs. The temporal relation between the influx of inflammatory cells into the nasal lumen and the onset of nasal congestion underlies the model's relevance to the exploration of the pathogenic mechanism(s) during viral rhinitis. Images Figure 1 PMID:7537523

  4. The economics of time shared computing: Congestion, user costs and capacity

    NASA Technical Reports Server (NTRS)

    Agnew, C. E.

    1982-01-01

    Time shared systems permit the fixed costs of computing resources to be spread over large numbers of users. However, bottleneck results in the theory of closed queueing networks can be used to show that this economy of scale will be offset by the increased congestion that results as more users are added to the system. If one considers the total costs, including the congestion cost, there is an optimal number of users for a system which equals the saturation value usually used to define system capacity.

  5. Optimal weighting scheme for suppressing cascades and traffic congestion in complex networks.

    PubMed

    Yang, Rui; Wang, Wen-Xu; Lai, Ying-Cheng; Chen, Guanrong

    2009-02-01

    This paper is motivated by the following two related problems in complex networks: (i) control of cascading failures and (ii) mitigation of traffic congestion. Both problems are of significant recent interest as they address, respectively, the security of and efficient information transmission on complex networks. Taking into account typical features of load distribution and weights in real-world networks, we have discovered an optimal solution to both problems. In particular, we shall provide numerical evidence and theoretical analysis that, by choosing a proper weighting parameter, a maximum level of robustness against cascades and traffic congestion can be achieved, which practically rids the network of occurrences of the catastrophic dynamics.

  6. The comparison of network congestion avoidance algorithms in data exchange networks.

    NASA Astrophysics Data System (ADS)

    Grzyb, S.; Orłowski, P.

    2017-01-01

    Effective congestion control strategies allow in maintaining low delay and high throughput in data exchange networks. These requirements seem to be the most desired by network environment participants. Wide range of algorithms are proposed in the literature to approximate to these ideal parameters. All of these approaches are focused on alleviating the results of sudden, unexpected network state changes. This paper discuss a comparison of four control strategies, focused on congestion avoidance. All of them are in charge of queue length control in active network nodes. For research purpose, non-stationary, discrete, dynamical model of communication channel has been used. Research results are presented in table and chart form.

  7. Wandering spleen causing gastric outlet obstruction and pancreatitis.

    PubMed

    Sanchez, Ramon; Lobert, Philip; Herman, Richard; O'Malley, Ryan; Mychaliska, George

    2010-12-01

    Excessive splenic mobility (i.e. wandering spleen) is a rare condition caused by laxity or deficiency of all the spleen's normal ligamentous attachments in the left hypochondrium. In the pediatric population, a wandering spleen may present as an incidental finding, an abdominal mass or torsion of the vascular pedicle causing venous congestion and acute abdominal pain, and eventually infarction. We present an unusual case of wandering spleen causing pancreatitis and gastric outlet obstruction via direct external compression.

  8. Bootstrapping Results of Exercise Therapy and Education for Patients with Congestive Heart Failure

    ERIC Educational Resources Information Center

    Witta, E. Lea; Brubaker, Craig

    2003-01-01

    When studies are conducted over a period of time, the sample size typically decreases. In a study of the effects of exercise therapy and education with recovering congestive heart failure (CHF) patients (Brubaker, Witta, & Angelopoulus, 2003), the sample size decreased from over 40 to 9 participants after an 18-month time span. Although the…

  9. Post-Acute Home Care and Hospital Readmission of Elderly Patients with Congestive Heart Failure

    ERIC Educational Resources Information Center

    Li, Hong; Morrow-Howell, Nancy; Proctor, Enola K.

    2004-01-01

    After inpatient hospitalization, many elderly patients with congestive heart failure (CHF) are discharged home and receive post-acute home care from informal (family) caregivers and formal service providers. Hospital readmission rates are high among elderly patients with CHF, and it is thought that use of informal and formal services may reduce…

  10. The Impact of Family Functioning on Caregiver Burden among Caregivers of Veterans with Congestive Heart Failure

    ERIC Educational Resources Information Center

    Moore, Crystal Dea

    2010-01-01

    A cross-sectional study of 76 family caregivers of older veterans with congestive heart failure utilized the McMaster model of family functioning to examine the impact of family functioning variables (problem solving, communication, roles, affective responsiveness, and affective involvement) on caregiver burden dimensions (relationship burden,…

  11. Embolization of ovarian vein for pelvic congestion syndrome with ethylene vinyl alcohol copolymer (Onyx(®)).

    PubMed

    Marcelin, C; Izaaryene, J; Castelli, M; Barral, P A; Jacquier, A; Vidal, V; Bartoli, J M

    2017-06-21

    To evaluate the safety and efficacy of pelvic embolization using ethylene vinyl alcohol copolymer (Onyx(®)) for pelvic congestion syndrome. Between March 2012 to September 2016, 17 women (mean age, 44.7± 12.2 (SD) years; range: 34-71years) presenting with pelvic congestion syndrome were evaluated for transvenous embolization with Onyx(®). Pelvic congestion syndrome was initially diagnosed by clinical examination and the results of transvaginal Doppler ultrasound and further confirmed by pelvic venography. Primary and secondary clinical efficacy was defined respectively by the resolution of the symptoms after embolization and at the end of the follow-up, irrespective to the number of embolization procedures. Technical efficacy of embolization was 100% with no significant complications during and after embolization. After a mean follow-up time of 24.2 months (range: 6-69months) a primary and secondary clinical efficacy of 76.4% (13/17 women) and 94.1% (16/17 women) respectively were observed. Four women (23.5%) underwent a second embolization procedure with one woman requiring a third embolization procedure. These additional embolization procedures were associated with direct puncture of vulvar varices for sclerotherapy in two women. Five women (29%) had recurrent symptoms 21 months post-treatment (7-42months). Pelvic embolization using ethylene vinyl alcohol copolymer (Onyx(®)) has a favorable clinical success for pelvic congestion syndrome. Copyright © 2017. Published by Elsevier Masson SAS.

  12. Allergic rhinitis-induced nasal congestion: its impact on sleep quality.

    PubMed

    Storms, William

    2008-03-01

    Allergic rhinitis (AR) is an extremely common health problem affecting 20 to 40 million Americans and between 10-25% of the world's population. Patients with AR suffer from both nasal symptoms (congestion, rhinorrhea, itching, and sneezing) and ocular symptoms (itching, redness, and tearing). The negative impact on sleep quality and quantity, and consequently on various aspects of the patient's life, is an under-recognised and under-treated component of AR morbidity. Nasal congestion, which is one of the most bothersome and prevalent symptoms of AR, is thought to be the leading symptom responsible for rhinitis-related sleep problems. In addition to reducing clinical symptoms, pharmacologic therapies for AR that specifically reduce inflammatory cells and mediators - and therefore nasal congestion and other symptoms - should also improve sleep quality and overall quality of life (QOL). Intranasal corticosteroids (INS) are the current mainstay of therapy for AR. Results of a number of clinical trials demonstrate that INS effectively reduce nasal congestion and ocular symptoms, improve sleep quality, and decrease daytime somnolence. Intranasal corticosteroids have also proved to be effective in reducing symptoms of acute rhinosinusitis and nasal polyposis, both of which also negatively impact on sleep quality. Intranasal corticosteroids are considered safe due to their low systemic bioavailability.

  13. Acupuncture for nasal congestion: a prospective, randomized, double-blind, placebo-controlled clinical pilot study.

    PubMed

    Sertel, Serkan; Bergmann, Zazie; Ratzlaff, Kerstin; Baumann, Ingo; Greten, Henry Johannes; Plinkert, Peter Karl

    2009-01-01

    Nasal congestion is one of the most common complaints dealt with in otorhinolaryngology. Side effects of decongestants are frequently seen in patients with chronic nasal congestion. This leads to an increasing demand of alternative treatments such as acupuncture. Future studies on acupuncture should aim at objectifying effects by both physical measuring and double blinding. Therefore, we were interested in whether these effects can potentially be measured as increase in nasal airflow (NAF) in ventus ("wind") disease of traditional Chinese medicine (TCM). Twenty-four patients with a history of nasal congestion due to hypertrophic inferior turbinates or chronic sinusitis without polyposis were additionally diagnosed according to the Heidelberg model of TCM. They were asked to score the severity of their nasal congestion on a visual analog scale (VAS). The acupuncturist was blinded according to the Heidelberg blinding assay. NAF was measured by using active anterior rhinomanometry (ARM). Specific verum acupoints according to the Chinese medical diagnosis were tested against nonspecific control acupoints. VAS and NAF were scored and measured before and 15 and 30 minutes after acupuncture. Control acupuncture showed a significant improvement in VAS and a deterioration of NAF. Verum acupuncture showed highly significant improvements in VAS and NAF. In addition, verum acupuncture improved NAF and VAS significantly over time. Our control and verum acupoints fulfill the condition of a control and verum treatment, respectively. Measuring NAF by RRM and scoring VAS are possible and reflect acupuncture effects in vivo.

  14. Decisions, Decisions, Decisions: Recreation Site Choice with Expected Congestion and Social Interaction

    ERIC Educational Resources Information Center

    Snipes, Katherine H.

    2009-01-01

    A set of computer-based recreation choice experiments were run to examine the effect of expected congestion and social interactions on the decision making process. MouseTrace is a process-tracing program that recorded individual subject's information acquisitions and provided the necessary information to determine if subjects used attribute-based…

  15. Input-Output Modeling and Control of the Departure Process of Congested Airports

    NASA Technical Reports Server (NTRS)

    Pujet, Nicolas; Delcaire, Bertrand; Feron, Eric

    2003-01-01

    A simple queueing model of busy airport departure operations is proposed. This model is calibrated and validated using available runway configuration and traffic data. The model is then used to evaluate preliminary control schemes aimed at alleviating departure traffic congestion on the airport surface. The potential impact of these control strategies on direct operating costs, environmental costs and overall delay is quantified and discussed.

  16. Containing air pollution and traffic congestion: Transport policy and the environment in Singapore

    NASA Astrophysics Data System (ADS)

    Chin, Anthony T. H.

    Land transportation remains one of the main contributors of noise and air pollution in urban areas. This is in addition to traffic congestion and accidents which result in the loss of productive activity. While there is a close relationship between traffic volumes and levels of noise and air pollution, transport authorities often assume that solving traffic congestion would reduce noise and air pollutant levels. Tight control over automobile ownership and use in Singapore has contributed in improving traffic flows, travel speeds and air quality. The adoption of internationally accepted standards on automobile emissions and gasoline have been effective in reducing air pollution from motor vehicles. Demand management measures have largely focused on controlling the source of traffic congestion, i.e. private automobile ownership and its use especially within the Central Business District during the day. This paper reviews and analyzes the effectiveness of two measures which are instrumental in controlling congestion and automobile ownership, i.e. road pricing and the vehicle quota scheme (VQS). While these measures have been successful in achieving desired objectives, it has also led to the spreading of traffic externalities to other roads in the network, loss in consumer welfare and rent seeking by automobile traders.

  17. Integration of congestion control and adaptive playout for unicast media streaming

    NASA Astrophysics Data System (ADS)

    Kim, Yoonyoung; Kim, JongWon

    2003-11-01

    To ease multimedia streaming over the QoS-deficient Internet, the network-adaptive streaming has been introduced recently. For an unicast media streaming environment, TCP-friendly end-to-end congestion control is widely suggested to handle the network congestion. However, the congestion control usually gives abrupt changes in the available bandwidth between streaming systems and the performance of media streaming can be degraded. To help this situation, we can adaptively control the playback speed of audio and video by adopting the time-scale modification technique. It can mitigate the effect of network variations in delay and loss, especially focusing on the low-latency video streaming situation. In this paper, we attempt to improve the streaming quality, when the congestion control is applied, by taking advantage of the adaptive playout mechanism. It can pro-actively prepare for imminent change with the adaptive playout capability, by estimating the expected buffer level and adjusting change in transmission rate, and controlling the playback rate.

  18. CCS_WHMS: A Congestion Control Scheme for Wearable Health Management System.

    PubMed

    Kafi, Mohamed Amine; Ben Othman, Jalel; Bagaa, Miloud; Badache, Nadjib

    2015-12-01

    Wearable computing is becoming a more and more attracting field in the last years thanks to the miniaturisation of electronic devices. Wearable healthcare monitoring systems (WHMS) as an important client of wearable computing technology has gained a lot. Indeed, the wearable sensors and their surrounding healthcare applications bring a lot of benefits to patients, elderly people and medical staff, so facilitating their daily life quality. But from a research point of view, there is still work to accomplish in order to overcome the gap between hardware and software parts. In this paper, we target the problem of congestion control when all these healthcare sensed data have to reach the destination in a reliable manner that avoids repetitive transmission which wastes precious energy or leads to loss of important information in emergency cases, too. We propose a congestion control scheme CCS_WHMS that ensures efficient and fair data delivery while used in the body wearable system part or in the multi-hop inter bodies wearable ones to get the destination. As the congestion detection paradigm is very important in the control process, we do experimental tests to compare between state of the art congestion detection methods, using MICAz motes, in order to choose the appropriate one for our scheme.

  19. Political and Public Acceptability of Congestion Pricing: Ideology and Self-Interest

    ERIC Educational Resources Information Center

    Harsman, Bjorn; Quigley, John M.

    2010-01-01

    Studies of the "stated preferences" of households generally report public and political opposition by urban commuters to congestion pricing. It is thought that this opposition inhibits or precludes tolls and pricing systems that would enhance efficiency in the use of scarce roadways. This paper analyzes the only case in which road…

  20. Elephantiasis Nostras Verrucosa (ENV): a complication of congestive heart failure and obesity.

    PubMed

    Baird, Drew; Bode, David; Akers, Troy; Deyoung, Zachariah

    2010-01-01

    Congestive heart failure (CHF) and obesity are common medical conditions that have many complications and an increasing incidence in the United States. Presented here is a case of a disfiguring skin condition that visually highlights the dermatologic consequences of poorly controlled CHF and obesity. This condition will probably become more common as CHF and obesity increase in the US.

  1. The use of medical leeches for venous congestion. A review and case report.

    PubMed

    Buote, N J

    2014-01-01

    The medicinal leech, Hirudo medicinalis, has been used for hundreds of years in human medicine for a variety of diseases, most recently including venous congestion following reconstructive surgeries (skin flaps and reimplantations), excessive lingual and periorbital swelling, and non-traditional treatments for osteoarthritis, compartment syndrome and sialoadenitis. The treatment of venous congestion in animals using leeches has been mentioned anecdotally, but the only published report pertains to the use of leeches in a cat suffering from polycythemia vera. We report the use of medical grade leeches in a one-year-old male castrated Domestic Shorthaired cat presenting with severe swelling of the paw after sustaining a constrictive injury from a bandage. The limb use had become compromised and the swelling was not responsive to compression bandages so leech therapy was instituted for four days and the swelling dramatically improved. The patient's limb use improved back to normal and the constrictive wound went on to heal without complication. The use of leeches in this case allowed for resolution of severe venous congestion and a full return to function in this patient with no continued skin loss. The mechanism of action of hirudotherapy for venous congestion is to allow for an alternative egress of pooled venous blood leading to a reduction in capillary pressure and increases in arterial reperfusion of capillary beds. The human and veterinary applications, method, and potential complications with hirudotherapy are discussed in this review.

  2. 23 CFR 970.214 - Federal lands congestion management system (CMS).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... selecting congestion mitigation strategies that are the most time efficient and cost effective and that add...-metropolitan areas, consideration shall be given to strategies that promote alternative transportation systems... the use of alternate mode studies and implementation plans as components of the CMS. (4) A CMS will...

  3. 23 CFR 970.214 - Federal lands congestion management system (CMS).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... selecting congestion mitigation strategies that are the most time efficient and cost effective and that add...-metropolitan areas, consideration shall be given to strategies that promote alternative transportation systems... the use of alternate mode studies and implementation plans as components of the CMS. (4) A CMS will...

  4. 23 CFR 970.214 - Federal lands congestion management system (CMS).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... selecting congestion mitigation strategies that are the most time efficient and cost effective and that add...-metropolitan areas, consideration shall be given to strategies that promote alternative transportation systems... the use of alternate mode studies and implementation plans as components of the CMS. (4) A CMS will...

  5. Political and Public Acceptability of Congestion Pricing: Ideology and Self-Interest

    ERIC Educational Resources Information Center

    Harsman, Bjorn; Quigley, John M.

    2010-01-01

    Studies of the "stated preferences" of households generally report public and political opposition by urban commuters to congestion pricing. It is thought that this opposition inhibits or precludes tolls and pricing systems that would enhance efficiency in the use of scarce roadways. This paper analyzes the only case in which road…

  6. Congestion at Card and Book Catalogs--A Queuing Theory Approach.

    ERIC Educational Resources Information Center

    Bookstein, Abraham

    The question of whether a library's catalog should consist of cards arranged in a single alphabetical order (the "dictionary catalog) or be segregated as a separate file is discussed. Development is extended to encompass related problems involved in the creation of a book catalog. A model to study the effects of congestion at the catalog is…

  7. 23 CFR 973.214 - Indian lands congestion management system (CMS).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... the IRR transportation plan and the IRRTIP, when selecting strategies for implementation that provide... congestion and enhance mobility. (b) In addition to the requirements provided in § 973.204, the CMS must meet..., consideration shall be given to strategies that reduce private automobile travel and improve existing...

  8. 23 CFR 973.214 - Indian lands congestion management system (CMS).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... the IRR transportation plan and the IRRTIP, when selecting strategies for implementation that provide... congestion and enhance mobility. (b) In addition to the requirements provided in § 973.204, the CMS must meet..., consideration shall be given to strategies that reduce private automobile travel and improve existing...

  9. Congestive hepatopathy after Fontan operation and related factors assessed by transient elastography.

    PubMed

    Yoo, Byung Won; Choi, Jae Young; Eun, Lucy Youngmin; Park, Han Ki; Park, Young Hwan; Kim, Seung Up

    2014-10-01

    Congestive hepatopathy after a Fontan operation can have a major effect on long-term morbidity. We evaluated congestive hepatopathy in patients with Fontan circulation using transient elastography to determine which risk factors for hepatopathy are related to liver stiffness (LS). We evaluated 46 patients with Fontan circulation and 26 with right side heart failure (RHF) and hepatic congestion using laboratory tests, the aspartate aminotransferase-to-platelet ratio index, ultrasonography, and transient elastography. The LS value was significantly greater in the Fontan group (21.1±8.0 kPa) than in the RHF group (10.0±9.0 kPa). The total bilirubin and albumin serum levels, white blood cell count, and aspartate aminotransferase to platelet ratio index correlated significantly with LS in the Fontan group. Of the risk factors, age at evaluation (r=0.42, P=.004), age at Fontan completion (r=0.51, P<.001), inferior vena cava diameter (r=0.35, P=.02), and spleen size (r=0.53, P=.002) correlated significantly with LS. Nineteen patients in the Fontan group (41.3%) had abnormal ultrasound findings, and the frequency of abnormal findings increased with increasing LS (P=.002). In the subgroup with the greatest LS value (≥30 kPa), 88.9% had abnormal ultrasound findings and 44.4% liver cirrhosis. Multivariate analysis revealed that age at Fontan procedure completion and total bilirubin were independent risk factors for hepatopathy. The present study revealed that congestive hepatopathy developed in a significant fraction of patients with long-term Fontan circulation and that transient elastography could be an easy and useful method to assess congestive hepatopathy in these patients. Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

  10. Impact of traffic congestion on road accidents: a spatial analysis of the M25 motorway in England.

    PubMed

    Wang, Chao; Quddus, Mohammed A; Ison, Stephen G

    2009-07-01

    Traffic congestion and road accidents are two external costs of transport and the reduction of their impacts is often one of the primary objectives for transport policy makers. The relationship between traffic congestion and road accidents however is not apparent and less studied. It is speculated that there may be an inverse relationship between traffic congestion and road accidents, and as such this poses a potential dilemma for transport policy makers. This study aims to explore the impact of traffic congestion on the frequency of road accidents using a spatial analysis approach, while controlling for other relevant factors that may affect road accidents. The M25 London orbital motorway, divided into 70 segments, was chosen to conduct this study and relevant data on road accidents, traffic and road characteristics were collected. A robust technique has been developed to map M25 accidents onto its segments. Since existing studies have often used a proxy to measure the level of congestion, this study has employed a precise congestion measurement. A series of Poisson based non-spatial (such as Poisson-lognormal and Poisson-gamma) and spatial (Poisson-lognormal with conditional autoregressive priors) models have been used to account for the effects of both heterogeneity and spatial correlation. The results suggest that traffic congestion has little or no impact on the frequency of road accidents on the M25 motorway. All other relevant factors have provided results consistent with existing studies.

  11. Lung sound patterns help to distinguish congestive heart failure, chronic obstructive pulmonary disease, and asthma exacerbations.

    PubMed

    Wang, Zhen; Xiong, Ying Xia

    2012-01-01

    Although congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), and asthma patients typically present with abnormal auscultatory findings on lung examination, respiratory sounds are not normally subjected to rigorous analysis. The aim of this study was to evaluate in detail the distribution of respiratory sound intensity in CHF, COPD, and asthma patients during acute exacerbation. Respiratory sounds throughout the respiratory cycle were captured and displayed using an acoustic-based imaging technique. Breath sound distribution was mapped to create a gray-scale sequence of two-dimensional images based on intensity of sound (vibration). Consecutive CHF (n = 22), COPD (n = 19), and asthma (n = 18) patients were imaged at the time of presentation to the emergency department (ED). Twenty healthy subjects were also enrolled as a comparison group. Geographical area of the images and respiratory sound patterns were quantitatively analyzed. In healthy volunteers and COPD patients, the median (interquartile range [IQR]) geographical areas of the vibration energy images were similar, at 75.6 (IQR = 6.0) and 75.8 (IQR = 10.8) kilopixels, respectively (p > 0.05). Compared to healthy volunteers and COPD patients, areas for CHF and asthma patients were smaller, at 66.9 (IQR = 9.9) and 53.9 (IQR = 15.6) kilopixels, respectively (p < 0.05). The geographic area ratios between the left and right lungs for healthy volunteers and CHF and COPD patients were 1.0 (IQR = 0.2), 1.0 (IQR = 0.2), and 1.0 (IQR = 0.1), respectively. Compared to healthy volunteers, the geographic area ratio between the left and right lungs for asthma patients was 0.5 (IQR = 0.4; p < 0.05). In healthy volunteers and CHF patients, the ratios of vibration energy values at peak inspiration and expiration (peak I/E ratio) were 4.6 (IQR = 4.4) and 4.7 (IQR = 3.5). In marked contrast, the peak I/E ratios of COPD and asthma patients were 3.4 (= 2.1) and 0.1 (IQR = 0.3; p < 0.05), respectively. The

  12. Long-chain monounsaturated fatty acids and incidence of congestive heart failure in two prospective cohorts

    PubMed Central

    Imamura, Fumiaki; Lemaitre, Rozenn N.; King, Irena B.; Song, Xiaoling; Steffen, Lyn M.; Folsom, Aaron R.; Siscovick, David S.; Mozaffarian, Dariush

    2013-01-01

    Background Decades-old animal experiments suggested dietary long-chain monounsaturated fatty acids (LCMUFA) caused cardiotoxicity, leading, for example, Canada to develop Canadian-oil-low-in-erucic-acid (Canola) from rapeseed. However, potential cardiotoxicity in humans and contemporary dietary sources of LCMUFA are unknown. Methods and Results We prospectively investigated associations of plasma phospholipid LCMUFA (20:1, 22:1, and 24:1), objective biomarkers of exposure, with incidence congestive heart failure (CHF) in two independent cohorts: 3,694 older adults (mean age=75.2±5.2 years) in the Cardiovascular Health Study (CHS, 1992–2006), and 3,577 middle-aged adults (mean age=54.1±5.8 years) in the Atherosclerosis Risk in Communities Study Minnesota subcohort (ARIC, 1987–2008). We further examined dietary correlates of circulating LCMUFA in CHS and ARIC, and US dietary sources of LCMUFA in the 2003–2010 National Health and Nutrition Examination Survey (NHANES). In CHS, 997 CHF events occurred during 39,238 person-years; and in ARIC, 330 events during 64,438 person-years. After multivariable-adjustment, higher levels of 22:1 and 24:1 were positively associated with greater incident CHF in both CHS and ARIC: hazard ratios (95% confidence interval)=1.34 (1.02–1.76) and 1.57 (1.11–2.23) for highest vs. lowest quintiles of 22:1, respectively; and 1.75 (1.23–2.50) and 1.92 (1.22–3.03) for 24:1, respectively (P-trend≤0.03 each). A variety of foods related to circulating LCMUFA in CHS and ARIC, consistent with food sources of LCMUFA in NHANES, including fish, poultry, meats, whole grains, and mustard. Conclusions Higher circulating levels of 22:1 and 24:1, with apparently diverse dietary sources, were associated with incident CHF in two independent cohorts, suggesting possible cardiotoxicity of LCMUFA in humans. PMID:23487436

  13. Development of potential methods for testing congestion control algorithm implemented in vehicle-to-vehicle communications.

    PubMed

    Hsu, Chung-Jen; Fikentscher, Joshua; Kreeb, Robert

    2017-05-29

    A channel congestion problem might occur when the traffic density increases because the number of basic safety messages carried on the communication channel also increases in vehicle-to-vehicle communications. A remedy algorithm proposed in SAE J2945/1 is designed to address the channel congestion issue by decreasing transmission frequency and radiated power. This study is to develop potential test procedures for evaluating or validating the congestion control algorithm. Simulations of a reference unit transmitting at a higher frequency are implemented to emulate a number of onboard equipment (OBE) transmitting at the normal interval of 100 ms (10 Hz). When the transmitting interval is reduced to 1.25 ms (800 Hz), the reference unit emulates 80 vehicles transmitting at 10 Hz. By increasing the number of reference units transmitting at 800 Hz in the simulations, the corresponding channel busy percentages are obtained. An algorithm for Global Positioning System (GPS) data generation of virtual vehicles is developed for facilitating the validation of transmission intervals in the congestion control algorithm. Channel busy percentage is the channel busy time over a specified period of time. Three or 4 reference units are needed to generate channel busy percentages between 50 and 80%, and 5 reference units can generate channel busy percentages above 80%. The proposed test procedures can verify the operation of congestion control algorithm when channel busy percentages are between 50 and 80% and above 80%. By using a GPS data generation algorithm, the test procedures can also verify the transmission intervals when traffic densities are 80 and 200 vehicles in a radius of 100 m. A suite of test tools with functional requirements is also proposed for facilitating the implementation of test procedures. The potential test procedures for a congestion control algorithm are developed based on the simulation results of channel busy percentage and the GPS data generation

  14. Wind power development in the United States: Effects of policies and electricity transmission congestion

    NASA Astrophysics Data System (ADS)

    Hitaj, Claudia

    In this dissertation, I analyze the drivers of wind power development in the United States as well as the relationship between renewable power plant location and transmission congestion and emissions levels. I first examine the role of government renewable energy incentives and access to the electricity grid on investment in wind power plants across counties from 1998-2007. The results indicate that the federal production tax credit, state-level sales tax credit and production incentives play an important role in promoting wind power. In addition, higher wind power penetration levels can be achieved by bringing more parts of the electricity transmission grid under independent system operator regulation. I conclude that state and federal government policies play a significant role in wind power development both by providing financial support and by improving physical and procedural access to the electricity grid. Second, I examine the effect of renewable power plant location on electricity transmission congestion levels and system-wide emissions levels in a theoretical model and a simulation study. A new renewable plant takes the effect of congestion on its own output into account, but ignores the effect of its marginal contribution to congestion on output from existing plants, which results in curtailment of renewable power. Though pricing congestion removes the externality and reduces curtailment, I find that in the absence of a price on emissions, pricing congestion may in some cases actually increase system-wide emissions. The final part of my dissertation deals with an econometric issue that emerged from the empirical analysis of the drivers of wind power. I study the effect of the degree of censoring on random-effects Tobit estimates in finite sample with a particular focus on severe censoring, when the percentage of uncensored observations reaches 1 to 5 percent. The results show that the Tobit model performs well even at 5 percent uncensored observations

  15. Percutaneous balloon dilation of severe pulmonary valve stenosis in patients with cyanosis and congestive heart failure.

    PubMed

    Tefera, Endale; Qureshi, Shakeel A; Bermudez-Cañete, Ramón; Rubio, Lola

    2014-08-01

    This article reports outcomes of percutaneous balloon dilation in patients with severe pulmonary valve stenosis, in particular in those treated late with cyanosis, congestive heart failure, and pericardial effusion. Percutaneous balloon dilation is the treatment of choice for pulmonary valve stenosis. Although earlier intervention may produce better results, patients may present late with congestive heart failure and cyanosis. Fifty-five patients who underwent pulmonary valve balloon dilation, were grouped into two groups, based on the presence or absence of congestive right heart failure and/or central cyanosis. Group I included 33 patients with severe pulmonary valve stenosis, but without clinical evidence of congestive right heart failure in the form of liver enlargement, raised jugular venous pressure, and peripheral edema and/or central cyanosis and group II included 22 patients with severe pulmonary valve stenosis and congestive right heart failure and/or central cyanosis. Their outcomes were compared. Doppler measured transvalvar pressure gradient decreased from 110.2 ± 34.0 mm Hg before to 52.5 ± 28.7 mm Hg in group I after dilation (P < 0.001), and from 138.4 ± 32.3 mm Hg to 53.9 ± 19.3 mm Hg in group II, (P < 0.001). Complications included ventricular tachycardia/fibrillation in three patients and severe bradycardia in one patient in group II. Twelve patients in group II developed clinical and radiologic evidence of reperfusion injury/pulmonary edema within the first 24 hr of intervention and needed ventilation for 2-9 days. Three of these patients died from intractable pulmonary edema. On follow up, clinical and echocardiographic improvement parameters were similar in the two groups. Those patients with severe pulmonary valve stenosis with congestive right heart failure, especially those with pericardial effusion, ascites and cyanosis, represent an important technical and clinical challenge. They are a high-risk group with or

  16. The Physics of Traffic Congestion and Road Pricing in Transportation Planning

    NASA Astrophysics Data System (ADS)

    Levinson, David

    2010-03-01

    This presentation develops congestion theory and congestion pricing theory from its micro- foundations, the interaction of two or more vehicles. Using game theory, with a two- player game it is shown that the emergence of congestion depends on the players' relative valuations of early arrival, late arrival, and journey delay. Congestion pricing can be used as a cooperation mechanism to minimize total costs (if returned to the players). The analysis is then extended to the case of the three- player game, which illustrates congestion as a negative externality imposed on players who do not themselves contribute to it. A multi-agent model of travelers competing to utilize a roadway in time and space is presented. To realize the spillover effect among travelers, N-player games are constructed in which the strategy set includes N+1 strategies. We solve the N-player game (for N = 7) and find Nash equilibria if they exist. This model is compared to the bottleneck model. The results of numerical simulation show that the two models yield identical results in terms of lowest total costs and marginal costs when a social optimum exists. Moving from temporal dynamics to spatial complexity, using consistent agent- based techniques, we model the decision-making processes of users and infrastructure owner/operators to explore the welfare consequence of price competition, capacity choice, and product differentiation on congested transportation networks. Component models include: (1) An agent-based travel demand model wherein each traveler has learning capabilities and unique characteristics (e.g. value of time); (2) Econometric facility provision cost models; and (3) Representations of road authorities making pricing and capacity decisions. Different from small-network equilibrium models in prior literature, this agent- based model is applicable to pricing and investment analyses on large complex networks. The subsequent economic analysis focuses on the source, evolution

  17. A model to identify urban traffic congestion hotspots in complex networks

    PubMed Central

    Solé-Ribalta, Albert; Gómez, Sergio

    2016-01-01

    The rapid growth of population in urban areas is jeopardizing the mobility and air quality worldwide. One of the most notable problems arising is that of traffic congestion. With the advent of technologies able to sense real-time data about cities, and its public distribution for analysis, we are in place to forecast scenarios valuable for improvement and control. Here, we propose an idealized model, based on the critical phenomena arising in complex networks, that allows to analytically predict congestion hotspots in urban environments. Results on real cities’ road networks, considering, in some experiments, real traffic data, show that the proposed model is capable of identifying susceptible junctions that might become hotspots if mobility demand increases. PMID:27853535

  18. Implementation of the Algorithm for Congestion control in the Dynamic Circuit Network (DCN)

    NASA Astrophysics Data System (ADS)

    Nalamwar, H. S.; Ivanov, M. A.; Buddhawar, G. U.

    2017-01-01

    Transport Control Protocol (TCP) incast congestion happens when a number of senders work in parallel with the same server where the high bandwidth and low latency network problem occurs. For many data center network applications such as a search engine, heavy traffic is present on such a server. Incast congestion degrades the entire performance as packets are lost at a server side due to buffer overflow, and as a result, the response time becomes longer. In this work, we focus on TCP throughput, round-trip time (RTT), receive window and retransmission. Our method is based on the proactive adjust of the TCP receive window before the packet loss occurs. We aim to avoid the wastage of the bandwidth by adjusting its size as per the number of packets. To avoid the packet loss, the ICTCP algorithm has been implemented in the data center network (ToR).

  19. Simple platelet markers: Mean platelet volume and congestive heart failure coexistent with periodontal disease. Pilot studies.

    PubMed

    Czerniuk, Maciej R; Bartoszewicz, Zbigniew; Dudzik-Niewiadomska, Iwona; Pilecki, Tomasz; Górska, Renata; Filipiak, Krzysztof J

    2017-07-17

    Conducted pilot study concerning mean platelet volume parameter among patients suffering from congestive heart failure and periodontal disease. Examination of dynamic changes of platelet and periodontal markers in group of 50 patients before and an average of 6 months subsequent to professional periodontal treatment. Both platelet and periodontal parameters decreased after periodontal treatment, what is more, the decrease of mean platelet volume (MPV) value due to periodontal disease/mm improvement was shown to be statistically significant (p = 0.05). Improvement of periodontal status may influence decrease of MPV value andincrease of congestive heart failure treatment efficacy and effect patient comfort. It is a new, not frequently used pattern of chronic disease treatment optimalization.

  20. Optimizing congestion and emissions via tradable credit charge and reward scheme without initial credit allocations

    NASA Astrophysics Data System (ADS)

    Zhu, Wenlong; Ma, Shoufeng; Tian, Junfang

    2017-01-01

    This paper investigates the revenue-neutral tradable credit charge and reward scheme without initial credit allocations that can reassign network traffic flow patterns to optimize congestion and emissions. First, we prove the existence of the proposed schemes and further decentralize the minimum emission flow pattern to user equilibrium. Moreover, we design the solving method of the proposed credit scheme for minimum emission problem. Second, we investigate the revenue-neutral tradable credit charge and reward scheme without initial credit allocations for bi-objectives to obtain the Pareto system optimum flow patterns of congestion and emissions; and present the corresponding solutions are located in the polyhedron constituted by some inequalities and equalities system. Last, numerical example based on a simple traffic network is adopted to obtain the proposed credit schemes and verify they are revenue-neutral.

  1. Hybrid control of bifurcation and chaos in stroboscopic model of Internet congestion control system

    NASA Astrophysics Data System (ADS)

    Ding, Da-Wei; Zhu, Jie; Luo, Xiao-Shu

    2008-01-01

    Interaction between transmission control protocol (TCP) and random early detection (RED) gateway in the Internet congestion control system has been modelled as a discrete-time dynamic system which exhibits complex bifurcating and chaotic behaviours. In this paper, a hybrid control strategy using both state feedback and parameter perturbation is employed to control the bifurcation and stabilize the chaotic orbits embedded in this discrete-time dynamic system of TCP/RED. Theoretical analysis and numerical simulations show that the bifurcation is delayed and the chaotic orbits are stabilized to a fixed point, which reliably achieves a stable average queue size in an extended range of parameters and even completely eliminates the chaotic behaviour in a particular range of parameters. Therefore it is possible to decrease the sensitivity of RED to parameters. By using the hybrid strategy, we may improve the stability and performance of TCP/RED congestion control system significantly.

  2. Bitrate adaptation flow control and client-based congestion control for multimedia-on-demand

    NASA Astrophysics Data System (ADS)

    Chan, Siu-Ping; Kok, Chi-Wah

    2003-06-01

    A flow control for streaming multimedia data over UDP on IP network is presented. The bitrate adaptation algorithm embedded in the protocol is considered to be an end-to-end mechanism in the application level. The flow control system constantly maintains the streaming buffer at a prescribed capacity even with bursty network losses by adapting the multimedia bitrate B from the streaming codec. A congestion control algorithm which is considered to be located in a lower level than that of the flow control mechanism is presented. It works together with the presented flow control to resolve network congestion problems while maintaining a degree of TCP-friendliness by changing the sending rate R at the server. Simulation results obtained from NS2 have shown better resource allocation can be obtained, and an overall incrase in the average sending rate and hence better quality of streaming media is observed.

  3. Cardiomyopathy and right-sided congestive heart failure in a red-tailed hawk (Buteo jamaicensis).

    PubMed

    Knafo, S Emmanuelle; Rapoport, Gregg; Williams, Jamie; Brainard, Benjamin; Driskell, Elizabeth; Uhl, Elizabeth; Crochik, Sonia; Divers, Stephen J

    2011-03-01

    A 15-year-old female red-tailed hawk (Buteo jamaicensis) was evaluated because of dyspnea, anorexia, and coelomic distension. Diagnostic imaging results confirmed severe coelomic effusion and revealed a markedly dilated right ventricle. The diagnosis was right-sided congestive heart failure. Results of measurements of vitamin E, selenium, lead, zinc, and cardiac troponin levels were normal or nondiagnostic. The hawk was treated with furosemide, antifungal and antimicrobial agents, and supplemental fluids and oxygen, but euthanasia was elected because of the poor prognosis and the practical difficulties associated with intensive case management. To our knowledge, this is the first described case of cardiomyopathy and congestive heart failure in a captive red-tailed hawk.

  4. Congestion analysis of pilgrims in Hajj and Umrah congregation using block matching and optical flow

    NASA Astrophysics Data System (ADS)

    Farooq, Sumaiyya; Khan, Shoab A.; Usman Akram, M.

    2017-01-01

    A novel method has been proposed to classify the motion of pilgrims with respect to congestion level in the holy mosque of Makkah. Millions of Muslims visit this mosque during Hajj and Umrah every year. A large number of security personnel is required to maintain the smooth flow of pilgrims in order to avert any catastrophe. Therefore, it is inevitable to design a computer aided system to reduce human effort. The proposed system pre-processes input images to segregate the moving shadows and pilgrims in order to nullify the false motion due to moving shadows. A hybrid method consisting of block matching and optical flow techniques has been used for the computation of motion vectors. Decision tree classifier is used on the number of motion vectors having non-zero magnitude. Experiments show that the proposed system has promising results yielding an accuracy of 90.58% for the congestion classification of pilgrims.

  5. A model to identify urban traffic congestion hotspots in complex networks.

    PubMed

    Solé-Ribalta, Albert; Gómez, Sergio; Arenas, Alex

    2016-10-01

    The rapid growth of population in urban areas is jeopardizing the mobility and air quality worldwide. One of the most notable problems arising is that of traffic congestion. With the advent of technologies able to sense real-time data about cities, and its public distribution for analysis, we are in place to forecast scenarios valuable for improvement and control. Here, we propose an idealized model, based on the critical phenomena arising in complex networks, that allows to analytically predict congestion hotspots in urban environments. Results on real cities' road networks, considering, in some experiments, real traffic data, show that the proposed model is capable of identifying susceptible junctions that might become hotspots if mobility demand increases.

  6. A model to identify urban traffic congestion hotspots in complex networks

    NASA Astrophysics Data System (ADS)

    Solé-Ribalta, Albert; Gómez, Sergio; Arenas, Alex

    2016-10-01

    The rapid growth of population in urban areas is jeopardizing the mobility and air quality worldwide. One of the most notable problems arising is that of traffic congestion. With the advent of technologies able to sense real-time data about cities, and its public distribution for analysis, we are in place to forecast scenarios valuable for improvement and control. Here, we propose an idealized model, based on the critical phenomena arising in complex networks, that allows to analytically predict congestion hotspots in urban environments. Results on real cities' road networks, considering, in some experiments, real traffic data, show that the proposed model is capable of identifying susceptible junctions that might become hotspots if mobility demand increases.

  7. A Study of the Effects of Congestion Information and a Priority Boarding Pass in a Theme Park with Multi-Agents

    NASA Astrophysics Data System (ADS)

    Tone, Tetsuya; Kohara, Kazuhiro

    We have investigated ways to reduce congestion in a theme park with multi-agents. We constructed a theme park model called Digital Park 1.0 with twenty-three attractions similar in form to Tokyo Disney Sea. We consider not only congestion information (number of vistors standing in line at each attraction) but also the advantage of a priority boarding pass, like Fast Pass which is used at Tokyo Disney Sea. The congestion-information-usage ratio, which reflects the ratio of visitors who behave according to congestion information, was changed from 0% to 100% in both models, with and without priority boarding pass. The “mean stay time of visitors" is a measure of satisfaction. The smaller mean stay time, the larger degree of satisfaction. Here, a short stay time means a short wait time. The resluts of each simulation are averaged over ten trials. The main results are as follows. (1) When congestion-information-usage ratio increased, the mean stay time decreases. When 20% of visitors behaved according to congestion information, the mean stay time was reduced by 30%. (2) A priority boarding pass reduced congestion, and mean stay time was reduced by 15%. (3) When visitors used congestion information and a priority boarding pass, mean stay time was further reduced. When the congestion-information-usage ratio was 20%, mean stay time was reduced by 35%. (4) When congestion-information-usage ratio was over 50%, the congestion reduction effects reached saturation.

  8. RESTRICTIVE CARDIOMYOPATHY AND SECONDARY CONGESTIVE HEART FAILURE IN A MCDOWELL'S CARPET PYTHON (MORELIA SPILOTA MCDOWELLI).

    PubMed

    Schilliger, Lionel; Chetboul, Valérie; Damoiseaux, Cécile; Nicolier, Alexandra

    2016-12-01

    Echocardiography is an established and noninvasive diagnostic tool used in herpetologic cardiology. Various cardiac lesions have been previously described in reptiles with the exception of restrictive cardiomyopathy. In this case report, restrictive cardiomyopathy and congestive heart failure associated with left atrial and sinus venosus dilation were diagnosed in a 2-yr-old captive lethargic McDowell's carpet python ( Morelia spilota mcdowelli), based on echocardiographic, Doppler, and histopathologic examinations. This cardiomyopathy was also associated with thrombosis within the sinus venosus.

  9. Distributed Channel Selection in CRAHNs with Heterogeneous Spectrum Opportunities: A Local Congestion Game Approach

    NASA Astrophysics Data System (ADS)

    Xu, Yuhua; Wu, Qihui; Wang, Jinlong; Min, Neng; Anpalagan, Alagan

    This letter investigates the problem of distributed channel selection in cognitive radio ad hoc networks (CRAHNs) with heterogeneous spectrum opportunities. Firstly, we formulate this problem as a local congestion game, which is proved to be an exact potential game. Then, we propose a spatial best response dynamic (SBRD) to rapidly achieve Nash equilibrium via local information exchange. Moreover, the potential function of the game reflects the network collision level and can be used to achieve higher throughput.

  10. Nonlinear dynamics of internet congestion control: A frequency-domain approach

    NASA Astrophysics Data System (ADS)

    Gentile, Franco S.; Moiola, Jorge L.; Paolini, Eduardo E.

    2014-04-01

    In this paper a fluid-flow model for TCP congestion avoidance combined with different AQM schemes is analyzed. The conditions for the appearance of Hopf bifurcations are stated analytically using frequency-domain techniques. The proposed methodology allows the characterization of the emerging periodic orbits, providing approximations of their amplitude and frequency. In addition, multiple oscillations and limit cycle bifurcations are found via numerical tools.

  11. ROBS: a novel architecture of reliable optical burst switching with congestion control

    NASA Astrophysics Data System (ADS)

    Luo, Jiangtao; Zhang, Zhizhong; Qiu, Shaofeng; Wang, Jun

    2005-02-01

    In this paper, we propose a novel modified architecture of Optical Burst-Switched Networks, called Reliable Optical Burst Switching (ROBS), which introduces congestion control and retransmission mechanisms of TCP to OBS layer. Design scheme of edge and core nodes for ROBS are both demonstrated. Part of the ROBS function has been implemented on ns-2 platform. Performance improvements due to burst retransmission are simulated and presented.

  12. Modeling Interregional Transmission Congestion in the NationalEnergy Modeling System

    SciTech Connect

    Gumerman, Etan; Chan, Peter; Lesieutre, Bernard; Marnay, Chris; Wang, Juan

    2006-05-25

    Congestion analysis using National Energy Modeling National Energy Modeling System (NEMS) or NEMS-derivatives, such as LBNL-NEMS, is subject to significant caveats because the generation logic inherent in NEMS limits the extent to which interregional transmission can be utilized and intraregional transmission is not represented at all. The EMM is designed primarily to represent national energy markets therefore regional effects may be simplified in ways that make congestion analysis harder. Two ways in particular come to mind. First, NEMS underutilizes the capability of the traditional electric grid as it builds the dedicated and detached grid. Second, it also undervalues the costs of congestion by allowing more transmission than it should, due to its use of a transportation model rather than a transmission model. In order to evaluate benefits of reduced congestion using LBNL-NEMS, Berkeley Lab identified three possible solutions: (1) implement true simultaneous power flow, (2) always build new plants within EMM regions even to serve remote load, and (3) the dedicated and detached grid should be part of the known grid. Based on these findings, Berkeley Lab recommends the following next steps: (1) Change the build logic that always places new capacity where it is needed and allow the transmission grid to be expanded dynamically. (2) The dedicated and detached grid should be combined with the traditional grid. (3) Remove the bias towards gas fired combine cycle and coal generation, which are the only types of generation currently allowed out of region. (4) A power flow layer should be embedded in LBNL-NEMS to appropriately model and limit transmission.

  13. Congestive heart failure patient monitoring using wearable Bio-impedance sensor technology.

    PubMed

    Seulki Lee; Squillace, Gabriel; Smeets, Christophe; Vandecasteele, Marianne; Grieten, Lars; de Francisco, Ruben; Van Hoof, Chris

    2015-08-01

    A new technique to monitor the fluid status of congestive heart failure (CHF) patients in the hospital is proposed and verified in a clinical trial with 8 patients. A wearable Bio-impedance (BioZ) sensor allows a continuous localized measurement which can be complement clinical tools in the hospital. Thanks to the multi-parametric approach and correlation analysis with clinical reference, BioZ is successfully shown as a promising parameter for continuous and wearable CHF patient monitoring application.

  14. PPARdelta activation normalizes cardiac substrate metabolism and reduces right ventricular hypertrophy in congestive heart failure.

    PubMed

    Jucker, Beat M; Doe, Christopher P; Schnackenberg, Christine G; Olzinski, Alan R; Maniscalco, Kristeen; Williams, Carolyn; Hu, Tom C-C; Lenhard, Stephen C; Costell, Melissa; Bernard, Roberta; Sarov-Blat, Lea; Steplewski, Klaudia; Willette, Robert N

    2007-07-01

    Previously, it was shown that selective deletion of peroxisome proliferator activated receptor delta (PPARdelta) in the heart resulted in a cardiac lipotoxicity, hypertrophy, and heart failure. The aim of the present study was to determine the effects of chronic and selective pharmacological activation of PPARdelta in a model of congestive heart failure. PPARdelta-specific agonist treatment (GW610742X at 30 and 100 mg/kg/day for 6-9 weeks) was initiated immediately postmyocardial infarction (MI) in Sprague-Dawley rats. Magnetic resonance imaging/spectroscopy was used to assess cardiac function and energetics. A 1-(13)C glucose clamp was performed to assess relative cardiac carbohydrate versus fat oxidation. Additionally, cardiac hemodynamics and reverse-transcription polymerase chain reaction gene expression analysis was performed. MI rats had significantly reduced left ventricle (LV) ejection fractions and whole heart phosphocreatine/adenosine triphosphate ratio compared with Sham animals (reduction of 43% and 14%, respectively). However, GW610742X treatment had no effect on either parameter. In contrast, the decrease in relative fat oxidation rate observed in both LV and right ventricle (RV) following MI (decrease of 58% and 54%, respectively) was normalized in a dose-dependent manner following treatment with GW610742X. These metabolic changes were associated with an increase in lipid transport/metabolism target gene expression (eg, CD36, CPT1, UCP3). Although there was no difference between groups in LV weight or infarct size measured upon necropsy, there was a dramatic reduction in RV hypertrophy and lung congestion (decrease of 22-48%, P<0.01) with treatment which was associated with a >7-fold decrease (P<0.05) in aterial natriuretic peptide gene expression in RV. Diuretic effects were not observed with GW610742X. In conclusion, chronic treatment with a selective PPARdelta agonist normalizes cardiac substrate metabolism and reduces RV hypertrophy and pulmonary

  15. Highly Dynamic and Adaptive Traffic Congestion Avoidance in Real-Time Inspired by Honey Bee Behavior

    NASA Astrophysics Data System (ADS)

    Wedde, Horst F.; Lehnhoff, Sebastian; van Bonn, Bernhard; Bay, Z.; Becker, S.; Böttcher, S.; Brunner, C.; Büscher, A.; Fürst, T.; Lazarescu, A. M.; Rotaru, E.; Senge, S.; Steinbach, B.; Yilmaz, F.; Zimmermann, T.

    Traffic congestions have become a major problem in metropolitan areas world-wide, within and between cities, to an extent where they make driving and transportation times largely unpredictable. Due to the highly dynamic character of congestion building and dissolving this phenomenon appears even to resist a formal treatment. Static approaches, and even more their global management, have proven counterproductive in practice. Given the latest progress in VANET technology and the remarkable commercially driven efforts like in the European C2C consortium, or the VSC Project in the US, allow meanwhile to tackle various aspects of traffic regulation through VANET communication. In this paper we introduce a novel, completely decentralized multi-agent routing algorithm (termed BeeJamA) which we have derived from the foraging behavior of honey bees. It is highly dynamic, adaptive, robust, and scalable, and it allows for both avoiding congestions, and minimizing traveling times to individual destinations. Vehicle guidance is provided well ahead of every intersection, depending on the individual speeds. Thus strict deadlines are imposed on, and respected by, the BeeJamA algorithm. We report on extensive simulation experiments which show the superior performance of BeeJamA over conventional approaches.

  16. A novel distributed model of the heart under normal and congestive heart failure conditions.

    PubMed

    Ravanshadi, Samin; Jahed, Mehran

    2013-04-01

    Conventional models of cardiovascular system frequently lack required detail and focus primarily on the overall relationship between pressure, flow and volume. This study proposes a localized and regional model of the cardiovascular system. It utilizes noninvasive blood flow and pressure seed data and temporal cardiac muscle regional activity to predict the operation of the heart under normal and congestive heart failure conditions. The analysis considers specific regions of the heart, namely, base, mid and apex of left ventricle. The proposed method of parameter estimation for hydraulic electric analogy model is recursive least squares algorithm. Based on simulation results and comparison to clinical data, effect of congestive heart failure in the heart is quantified. Accumulated results for simulated ejection fraction percentage of the apex, mid and base regions of the left ventricle in congestive heart failure condition were 39 ± 6, 36 ± 9 and 38 ± 8, respectively. These results are shown to satisfactorily match those found through clinical measurements. The proposed analytical method can in effect be utilized as a preclinical and predictive tool for high-risk heart patients and candidates for heart transplant, assistive device and total artificial heart.

  17. Monitoring lung resistivity changes in congestive heart failure patients using the bioimpedance technique.

    PubMed

    Zlochiver, Sharon; Radai, Michal M; Barak-Shinar, Deganit; Ben-Gal, Tuiva; Yaari, Vicky; Strasberg, Boris; Abboud, Shimon

    2005-01-01

    The feasibility of a novel, dedicated system for monitoring lung resistivity in congestive heart failure patients, implementing a hybrid approach of the bioimpedance technique, was assessed in this preliminary study. Thirty-three healthy volunteers and 34 congestive heart failure patients were measured with the PulmoTrace system (CardioInspect, Tel Aviv University, Tel Aviv, Israel) during tidal respiration, and the ability to monitor the respective lung resistivity values was assessed. Mean left and right lung resistivity values of 1205+/-163 and 1200+/-165 ohm.cm for the control group and 888+/-193 and 943+/-187 ohm.cm for the congestive heart failure group were found, indicating a significant (p<2.10(-7)) difference between the two groups. The results of long-term monitoring of two patients during medical treatment are also shown. This hybrid approach system is believed to improve diagnostic capabilities and help physicians to better adjust medication dosage on a frequent basis.

  18. Visibility graph analysis of heart rate time series and bio-marker of congestive heart failure

    NASA Astrophysics Data System (ADS)

    Bhaduri, Anirban; Bhaduri, Susmita; Ghosh, Dipak

    2017-09-01

    Study of RR interval time series for Congestive Heart Failure had been an area of study with different methods including non-linear methods. In this article the cardiac dynamics of heart beat are explored in the light of complex network analysis, viz. visibility graph method. Heart beat (RR Interval) time series data taken from Physionet database [46, 47] belonging to two groups of subjects, diseased (congestive heart failure) (29 in number) and normal (54 in number) are analyzed with the technique. The overall results show that a quantitative parameter can significantly differentiate between the diseased subjects and the normal subjects as well as different stages of the disease. Further, the data when split into periods of around 1 hour each and analyzed separately, also shows the same consistent differences. This quantitative parameter obtained using the visibility graph analysis thereby can be used as a potential bio-marker as well as a subsequent alarm generation mechanism for predicting the onset of Congestive Heart Failure.

  19. Altered regional myocardial metabolism in congestive cardiomyopathy detected by positron tomography

    SciTech Connect

    Geltman, E.M.; Smith, J.L.; Beecher, D.; Ludbrook, P.A.; Ter-Pogossian, M.M.; Sobel, B.E.

    1983-05-01

    The present study was performed to determine whether positron emission tomography performed after intravenous injection of /sup 11/C-palmitate permits detection and characterization of congestive cardiomyopathy. Positron emission tomography was performed after the intravenous injection of /sup 11/C-palmitate in 13 normal subjects, 17 patients with congestive cardiomyopathy, and six patients with initial transmural myocardial infarction (defined electrocardiographically). Regionally depressed accumulation of /sup 11/C-palmitate was assessed, characterized, and quantified in seven parallel transaxial reconstructions in each patient. Patients with cardiomyopathy exhibited a larger number of discrete noncontiguous regions of accumulation of palmitate within the myocardium than either control subjects or patients with transmural infarction (17.4 +/- 0.6 (SEM) versus 11.8 +/- 0.7 versus 10.3 +/- 0.6, p less than 0.005). Similarly, regions of accumulation of palmitate were irregularly shaped in patients with cardiomyopathy, with a longer normalized perimeter than either control subjects or patients with transmural infarction (2.0 +/- 0.05 versus 1.8 +/- 0.06 versus 1.9 +/- 0.09, p less than 0.05). Regional abnormalities of the accumulation of 11C-palmitate could not be explained by regional differences in left ventricular wall motion or myocardial perfusion. Thus, marked heterogeneity of regional myocardial accumulation of 11C-palmitate is detectable and quantifiable in patients with congestive cardiomyopathy by positron emission tomography and may be particularly valuable for early detection and characterization of cardiomyopathy.

  20. Pregnancy rhinitis in Turkish women: Do gestational week, BMI and parity affect nasal congestion?

    PubMed Central

    Ulkumen, Burak; Ulkumen, Burcu Artunc; Pala, Halil Gursoy; Celik, Onur; Sahin, Nevin; Karaca, Gizem; Demirdag, Meltem

    2016-01-01

    Objective: To determine the cumulative incidence of pregnancy rhinitis along with prevalence in different trimesters and to find out whether gestational age, BMI and parity have any effect on pregnancy related nasal congestion. Methods: In the prospective protocol at the obstetrics outpatient clinic, 167 pregnant women were enrolled consecutively. According to exclusion criteria, 67 of them were excluded. Visual-Analogue-Scale (VAS), Nasal-Obstructive-Symptom-Evaluation (NOSE) scale and Discharge-Inflammation-Polyps/Oedema (DIP) scoring were utilized for diagnosis of pregnancy rhinitis. Besides, weight, length, age, parity and week of pregnancy were recorded. Results: Total prevalence of pregnancy rhinitis was 17.17% and cumulative incidence was 38.89%. Our study revealed significant relation of NOSE score with both gestational week (r=0.474, p=0.001) and BMI (r=0.301, p=0.003). VAS score was significantly related with gestational week (r=0.409, p=0.001) and BMI (r=0.270, p=0.007). DIP score was found to be correlated only with gestational week (r=0.375, p=0.001). Conclusion: Cumulative incidence of pregnancy rhinitis was 38.89%. Nasal congestion was significantly associated with BMI and gestational week. Patients should be informed about unfavorable fetal and maternal outcomes of pregnancy related nasal congestion which is triggered by obesity and excessive weight gain in pregnancy. PMID:27648046

  1. Associating Liver Partition and Portal Vein Occlusion, Including Venous Congestion, Induction in Rats.

    PubMed

    Kawaguchi, Daisuke; Hiroshima, Yukihiko; Kikuchi, Yutaro; Matsuo, Kenichi; Tanaka, Kuniya

    2017-06-01

    Associating liver partition with portal vein occlusion for staged hepatectomy (ALPPS) is a recently developed strategy for inducing rapid hypertrophy of the future liver remnant (FLR). To explore possible mechanisms, we designed the first model of ALPPS with venous congestion (ALPPS+C) in rats. Rats were assigned randomly to 3 experimental groups: ALPPS, ALPPS+C and sham. Hepatic regeneration rate, Ki-67 and histopathology were assessed at 24 h, 48 h, and 7 days postoperatively. Hepatic regeneration rate was much higher for ALPPS+C than for ALPPS at 48 h and 7 days postoperatively (p<0.01). Microscopically, the regenerating liver showed greater hepatocyte density and smaller hepatocyte size in ALPPS+C than in ALPPS (p<0.01 for each). Greater hepatic regeneration in ALPPS+C than in ALPPS confirmed that we established a rat model of ALPPS with benefit from venous congestion. Producing a congested area may contribute importantly to rapid FLR hypertrophy during ALPPS. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  2. Evaluation of embolization for periuterine varices involving chronic pelvic pain secondary to pelvic congestion syndrome

    PubMed Central

    Siqueira, Flavio Meirelles; Monsignore, Lucas Moretti; Rosa-e-Silva, Julio Cesar; Poli-Neto, Omero Benedicto; de Castro-Afonso, Luis Henrique; Nakiri, Guilherme Seizem; Muglia, Valdair Francisco; Abud, Daniel Giansante

    2016-01-01

    OBJECTIVES: To evaluate the clinical response and success rate after periuterine varices embolization in patients with chronic pelvic pain secondary to pelvic congestion syndrome and to report the safety of endovascular treatment and its rate of complications. METHODS: Retrospective cohort of patients undergoing endovascular treatment of pelvic congestion syndrome in our department from January 2012 to November 2015. Data were analyzed based on patient background, imaging findings, embolized veins, rate of complications, and clinical response as indicated by the visual analog pain scale. RESULTS: We performed periuterine varices embolization in 22 patients during the study, four of which required a second embolization. Seventeen patients reported a reduction in pelvic pain after the first embolization and three patients reported a reduction in pelvic pain after the second embolization. Minor complications were observed in our patients, such as postural hypotension, postoperative pain, and venous perforation during the procedure, without clinical repercussion. CONCLUSION: Periuterine varices embolization in patients with chronic pelvic pain secondary to pelvic congestion syndrome appears to be an effective and safe technique. PMID:28076514

  3. Increased risk of congestive heart failure among infarctions with nighttime onset.

    PubMed

    Mukamal, K J; Muller, J E; Maclure, M; Sherwood, J B; Mittleman, M A

    2000-09-01

    The onset of acute myocardial infarction varies by time of day, with a peak in the morning and a trough at night. Whether infarct-related complications differ by the timing of the infarction is unknown. In the Determinants of Myocardial Infarction Onset Study, we performed chart reviews and face-to-face interviews with 3625 patients with acute myocardial infarction. We assessed the time of onset of symptoms, the presence of ventricular tachycardia or congestive heart failure, and peak creatine kinase levels (in 1043 patients). We found significant circadian variation in the risk of congestive heart failure (P =.001). The risk dropped from 17% for infarctions that began between 6 PM and midnight to 10% for infarctions that began between 6 AM and noon. Adjustment for differences in the time from symptom onset to presentation for care and use of thrombolytic agents did not change the results. We found no circadian variation in the risk of ventricular tachycardia or in peak creatine kinase levels. The risk of congestive heart failure is highest among infarctions that begin at night. Further research may clarify whether this reflects differences in the pathophysiologic characteristics of infarction or the quality of medical care provided for daytime and nighttime infarctions.

  4. Cerebral blood flow in patients with congestive heart failure treated with captopril

    SciTech Connect

    Paulson, O.B.; Jarden, J.O.; Godtfredsen, J.; Vorstrup, S.

    1984-05-31

    The effect of captopril on cerebral blood flow was studied in five patients with severe congestive heart failure and in five control subjects. Cerebral blood flow was measured by inhalation of /sup 133/xenon and registration of its uptake and washout from the brain by single photon emission computer tomography. In addition, cerebral (internal jugular) venous oxygen tension was determined in the controls. The measurements were made before and 15, 60, and 180 minutes after a single oral dose of captopril (6.25 mg in patients with congestive heart failure and 25 mg in controls). Despite a marked decrease in blood pressure, cerebral blood flow increased slightly in the patients with severe congestive heart failure. When a correction was applied to take account of a change in arterial carbon dioxide tension, however, cerebral blood flow was unchanged after captopril administration even in patients with the greatest decrease in blood pressure, in whom a decrease in cerebral blood flow might have been expected. In the controls, blood pressure was little affected by captopril, whereas a slight, but not statistically significant, decrease in cerebral blood flow was observed. The cerebral venous oxygen tension decreased concomitantly.

  5. Baroreflex Activation Therapy in Congestive Heart Failure: Novel Findings and Future Insights.

    PubMed

    Grassi, Guido; Brambilla, GianMaria; Pizzalla, Daniela Prata; Seravalle, Gino

    2016-08-01

    Congestive heart failure is characterized by hemodynamic and non-hemodynamic abnormalities, the latter including an activation of the sympathetic influences to the heart and peripheral circulation coupled with an impairment of baroreceptor control of autonomic function. Evidence has been provided that both these alterations are hallmark features of the disease with a specific relevance for the disease progression as well as for the development of life-threatening cardiac arrhythmias. In addition, a number of studies have documented in heart failure the adverse prognostic role of the sympathetic and baroreflex alterations, which both are regarded as major independent determinants of cardiovascular morbidity and mortality. This represents the pathophysiological and clinical background for the use of carotid baroreceptor activation therapy in the treatment of congestive heart failure. Promising data collected in experimental animal models of heart failure have supported the recent performance of pilot small-scale clinical studies, aimed at providing initial information in this area. The results of these studies demonstrated the clinical safety and efficacy of the intervention which has been tested in large-scale clinical studies. The present paper will critically review the background and main results of the published studies designed at defining the clinical impact of baroreflex activation therapy in congestive heart failure patients. Emphasis will be given to the strengths and limitations of such studies, which represent the background for the ongoing clinical trials testing the long-term effects of the device in heart failure patients.

  6. Morbid Obesity and Congestive Heart Failure Increase Operative Time and Room Time in Total Hip Arthroplasty.

    PubMed

    Gholson, J Joseph; Shah, Apurva S; Gao, Yubo; Noiseux, Nicolas O

    2016-04-01

    Obesity is increasingly common in patients having total hip arthroplasty, and previous studies have shown a correlation with increased operative time in total hip arthroplasty. Decreasing operative time and room time is essential to meeting the increased demand for total hip arthroplasty, and factors that influence these metrics should be quantified to allow for targeted reduction in time and adjusted reimbursement models. This is the first study to use a multivariate approach to identify which factors increase operative time and room time in total hip arthroplasty. The American College of Surgeons National Surgical Quality Improvement Program database was used to identify a cohort of 30,361 patients having total hip arthroplasty between 2006 and 2012. Patient demographics, comorbidities including body mass index, and anesthesia type were used to create generalized linear models identifying independent predictors of increased operative time and room time. Morbid obesity (body mass index >40) independently increased operative time by 13 minutes and room time 18 by minutes. Congestive heart failure led to the greatest increase in overall room time, resulting in a 20-minute increase. Anesthesia method further influenced room time, with general anesthesia resulting in an increased room time of 18 minutes compared with spinal or regional anesthesia. Obesity is the major driver of increased operative time in total hip arthroplasty. Congestive heart failure, general anesthesia, and morbid obesity each lead to substantial increases in overall room time, with congestive heart failure leading to the greatest increase in overall room time. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Preventing postoperative congestion in reverse pedicle digital island flaps when reconstructing composite tissue defects in the fingertip: a patient series.

    PubMed

    Matsuzaki, Hironori; Kouda, Hisao; Yamashita, Haruyoshi

    2012-01-01

    For reconstructing an injured fingertip, a reverse pedicle digital island flap can restore excellent function and appearance. However, postoperative flap congestion may lead to flap necrosis. We tested a method for dissecting the vascular pedicle to prevent congestion and to provide more reliable results. Between August 2002 and December 2010, we reconstructed 14 fingertips in 13 patients (average age, 43 years; range, 24 to 68 years; 9 men). Through a small zigzag incision, the digital artery and a 4-mm-wide subcutaneous venous network were elevated in retrograde fashion to facilitate venous drainage. All flaps healed completely without severe congestion or necrosis. Slight flexion contractures remained in the PIP (mean, 12°) and DIP (mean, 14°) joints. Our procedure is simpler and more reliable than other techniques, such as adding a narrow skin bridge to the pedicle or a venous anastomosis to prevent venous congestion, and it assures the survival of the flap.

  8. The effects of congestion charging on road traffic casualties: a causal analysis using difference-in-difference estimation.

    PubMed

    Li, Haojie; Graham, Daniel J; Majumdar, Arnab

    2012-11-01

    This paper aims to identify the impacts of the London congestion charge on road casualties within the central London charging zone. It develops a full difference-in-difference (DID) model that is integrated with generalized linear models, such as Poisson and Negative Binomial regression models. Covariates are included in the model to adjust for factors that violate the parallel trend assumption, which is critical in the DID model. The lower Bayesian Information Criterion value suggests that the full difference-in-difference model performs well in evaluating the relationship between road accidents and the London congestion charge as well as other socio-economic factors. After adjusting for a time trend and regional effects, the results show that the introduction of the London congestion charge has a significant influence on the incidence of road casualties. The congestion charge reduces the total number of car accidents, but is associated with an increase in two wheeled vehicle accidents.

  9. Congestive Myelopathy due to Intradural Spinal AVM Supplied by Artery of Adamkiewicz: Case Report with Brief Literature Review and Analysis of the Foix-Alajouanine Syndrome Definition

    PubMed Central

    Sood, Dinesh; Mistry, Kewal A.; Khatri, Garvit D.; Chadha, Veenal; Garg, Swati; Suthar, Pokhraj P.; Patel, Dhruv G.; Patel, Ankitkumar

    2015-01-01

    Summary Background Spinal arteriovenous malformations (AVMs) can lead to development of congestive myelopathy (Foix-Alajouanine syndrome). Spinal AVMs are rare and so is this syndrome. Diagnosis is often missed due to its rarity and confusing definitions of the Foix-Alajouanine syndrome. Case Report We report a case of a 47-year-old male patient suffering from this rare syndrome with an AVM arising from the artery of Adamkiewicz, which is another rarity. Our patient was treated by embolization of the lesion with 20% glue, after which he showed mild improvement of symptoms. We also present a brief review of literature on spinal AVMs and elucidate the evolution of the term Foix-Alajouanine syndrome. Conclusions Use of the term “Foix-Alajouanine syndrome” should be restricted to patients with progressive subacute to chronic neurological symptoms due to congestive myelopathy caused by intradural spinal AVMs. CT angiography should supplement DSA as preliminary Imaging modality. Patients may be treated with surgery or endovascular procedures. PMID:26171088

  10. PULMONARY ARTERIAL DISEASE ASSOCIATED WITH RIGHT-SIDED CARDIAC HYPERTROPHY AND CONGESTIVE HEART FAILURE IN ZOO MAMMALS HOUSED AT 2,100 M ABOVE SEA LEVEL.

    PubMed

    Juan-Sallés, Carles; Martínez, Liliana Sofía; Rosas-Rosas, Arely G; Parás, Alberto; Martínez, Osvaldo; Hernández, Alejandra; Garner, Michael M

    2015-12-01

    Subacute and chronic mountain sickness of humans and the related brisket disease of cattle are characterized by right-sided congestive heart failure in individuals living at high altitudes as a result of sustained hypoxic pulmonary hypertension. Adaptations to high altitude and disease resistance vary among species, breeds, and individuals. The authors conducted a retrospective survey of right-sided cardiac hypertrophy associated with pulmonary arterial hypertrophy or arteriosclerosis in zoo mammals housed at Africam Safari (Puebla, México), which is located at 2,100 m above sea level. Seventeen animals with detailed pathology records matched the study criterion. Included were 10 maras (Dolichotis patagonum), 2 cotton-top tamarins (Saguinus oedipus oedipus), 2 capybaras (Hydrochaeris hydrochaeris), and 1 case each of Bennet's wallaby (Macropus rufogriseus), nilgai antelope (Boselaphus tragocamelus), and scimitar-horned oryx (Oryx dammah). All had right-sided cardiac hypertrophy and a variety of arterial lesions restricted to the pulmonary circulation and causing arterial thickening with narrowing of the arterial lumen. Arterial lesions most often consisted of medial hypertrophy or hyperplasia of small and medium-sized pulmonary arteries. All maras also had single or multiple elevated plaques in the pulmonary arterial trunk consisting of fibrosis, accompanied by chondroid metaplasia in some cases. Both antelopes were juvenile and died with right-sided congestive heart failure associated with severe pulmonary arterial lesions. To the authors' knowledge, this is the first description of cardiac and pulmonary arterial disease in zoo mammals housed at high altitudes.

  11. Pathophysiological targets for beta-blocker therapy in congestive heart failure.

    PubMed

    Just, H

    1996-04-01

    The treatment of congestive heart failure has seen considerable changes: while treatment with diuretics, digitalis glycosides and vasodilators has remained the mainstay of therapy, recently neurohumeral inhibition has been developed as an important principle: ACE-inhibitors have been shown to significantly improve quality of life and exercise performance and to substantially reduce mortality. Beta-blockers have been employed with increasing success mainly in congestive heart failure due to dilated idiopathic cardiomyopathy, in which a significant improvement in symptoms and life expectancy has been demonstrated. However, the precise mechanisms by which beta-blockade improves congestive heart failure remain to be elucidated. In addition to direct sympathoadrenal inhibition, reduction of heart rate may also play a major role in the therapeutic efficacy of beta-blockade in congestive heart failure. In the normal human heart increase in heart rate is accompanied by an increase in myocardial contractile performance (Bowditch-Treppe phenomenon). In chronic heart failure the myocardium undergoes a phenotype change which includes alterations of the activity of enzymes regulating calcium homoeostasis. The sarcoplasmic reticulum calcium ATPase (SERCA) is depressed both in function, as well as in expression. At the same time the sarcolemmal sodium-calcium exchanger is increased both in function and in expression. The result is a characteristic change in calcium homoeostasis with decreased diastolic uptake of calcium into the sarcoplasmic reticulum with subsequently reduced calcium release during the next systole, resulting in reduced contractile performance. At the same time increased capacity of the sodium-calcium exchanger extrudes intracellular calcium ions to the extra-cellular space, thereby rendering these ions unavailable for the contractile cycle. A result of these, seemingly specific, phenotype changes is an alteration of the force/frequency relationship. Instead of

  12. Vibrational and thermal characterisation of a new chiral drug under investigation for the therapy of congestive heart failure

    NASA Astrophysics Data System (ADS)

    Taddei, Paola; Torreggiani, Armida; Fini, Giancarlo

    2002-12-01

    Racemic (5,6-bis 2-methyl propanoic acid-1,2,3,4-tetrahydro-naphtalen-2-yl)-methylammonium chloride, CHF-1035, under clinical investigation for the treatment of congestive heart failure, was here characterised by Raman and IR spectroscopies coupled with thermal analysis (thermogravimetry and differential scanning calorimetry). These techniques proved suitable for investigating the presence of different polymorphic forms, their relative stability and interconversion tendency in relation to industrial manufacturing processes undergone by the drug (i.e. grinding, compression, heating). Crystallisation experiments were carried out and two different CHF-1035 polymorphic forms were identified. Both grinding and heating revealed to cause a polymorphic transformation of the drug crystal form. It was hypothesised that a change in molecular packing occurs in the drug by effect of both treatments. The possible sources of polymorphism were identified in the -OCOCH(CH 3) groups and in the saturated ring. The non-ground sample showed two endothermic transitions; since they are reversible and not due to desolvation processes the system is probably enantiotropic.

  13. A new approach to early diagnosis of congestive heart failure disease by using Hilbert-Huang transform.

    PubMed

    Altan, Gokhan; Kutlu, Yakup; Allahverdi, Novruz

    2016-12-01

    Congestive heart failure (CHF) is a degree of cardiac disease occurring as a result of the heart's inability to pump enough blood for the human body. In recent studies, coronary artery disease (CAD) is accepted as the most important cause of CHF. This study focuses on the diagnosis of both the CHF and the CAD. The Hilbert-Huang transform (HHT), which is effective on non-linear and non-stationary signals, is used to extract the features from R-R intervals obtained from the raw electrocardiogram data. The statistical features are extracted from instinct mode functions that are obtained applying the HHT to R-R intervals. Classification performance is examined with extracted statistical features using a multilayer perceptron neural network. The designed model classified the CHF, the CAD patients and a normal control group with rates of 97.83%, 93.79% and 100%, accuracy, specificity and sensitivity, respectively. Also, early diagnosis of the CHF was performed by interpretation of the CAD with a classification accuracy rate of 97.53%, specificity of 98.18% and sensitivity of 97.13%. As a result, a single system having the ability of both diagnosis and early diagnosis of CHF is performed by integrating the CAD diagnosis method to the CHF diagnosis method.

  14. The function and significance of SERA2a in congestive heart failure: an analysis of gene therapy trials.

    PubMed

    Wu, Pei; Zhai, Yuting; Li, Dongye

    2017-01-30

    Congestive heart failure (CHF) is a widespread disease that has a negative impact on health, worldwide. Despite advances in therapies, morbidity, mortality and hospital discharges due to CHF remain high. Advances in the understanding of the pathophysiological mechanisms of CHF and the development of gene transfer technology have made gene therapy a realistic potential therapeutic method for CHF. Among the various potential targets, sarco-endoplasmic reticulum Ca2+-ATPase 2a (SERCA2a), which is an important protein in the regulation of Ca2+ cycling, has piqued the interest of many researchers. Restoring decreased SERCA2a activity in CHF could improve cardiac contractions and energetics, as well as reduce myocardial fibrosis and ventricular arrhythmias, and these benefits have been confirmed by studies using both in vivo and in vitro models. Following these promising preclinical results, SERCA2a gene therapy advanced to clinical trials. However, results of the clinical trials were controversial, leading some to question whether SERCA2a is the right target for CHF treatment. In this review, we illustrate the function and significance of SERCA2a in CHF, and more importantly, analyze possible causes of the controversial clinical trials results, with the aim of stimulating future research on the relationship between SERCA2a and CHF.

  15. Transplantation of adipose tissue-derived stromal cells promotes the survival of venous-congested skin flaps in rabbit ear.

    PubMed

    Xu, Nan; Guo, Shu; Wang, Yuxin; Sun, Qiang; Wang, Chenchao

    2015-03-01

    Venous congestion after skin flap transplantation usually slows blood flow velocity and induces skin flap necrosis and surgical failure. Adipose tissue-derived stromal cells (ADSCs) can promote neovascularization and have been extensively applied in cell transplantation therapy and tissue regeneration. However, their function has not been reported in venous-congested skin flaps. In this study, rabbit ADSCs were isolated and identified. We established a rabbit ear venous-congested skin flap model and injected ADSCs into points along the midlines of skin flaps. The survival conditions of venous-congested skin flaps on postoperative day 7 showed that there was obvious swelling, hemorrhage, or necrosis in skin flaps of the control group, while the skin flap survival rate in the ADSC treatment group significantly increased. Hematoxylin and eosin (HE) staining results indicated that compared with the control group, thrombosis was significantly relieved and neovascularization was observed in the ADSC treatment group. Immunofluorescence revealed that the CD34 expression level and the number of capillaries significantly increased in the ADSC treatment group. In summary, ADSC transplantation promotes neovascularization in venous-congested skin flaps and skin flap survival. Therefore, ADSC transplantation may be an effective measure for promoting the survival of venous-congested skin flaps.

  16. Controlling satellite communication system unwanted emissions in congested RF spectrum

    NASA Astrophysics Data System (ADS)

    Olsen, Donald; Heymann, Roger

    2007-09-01

    The International Telecommunication Union (ITU), a United Nations (UN) agency, is the agency that, under an international treaty, sets radio spectrum usage regulations among member nations. Within the United States of America (USA), the organization that sets regulations, coordinates an application for use, and provides authorization for federal government/agency use of the radio frequency (RF) spectrum is the National Telecommunications and Information Administration (NTIA). In this regard, the NTIA defines which RF spectrum is available for federal government use in the USA, and how it is to be used. The NTIA is a component of the United States (U.S.) Department of Commerce of the federal government. The significance of ITU regulations is that ITU approval is required for U.S. federal government/agency permission to use the RF spectrum outside of U.S. boundaries. All member nations have signed a treaty to do so. U.S. federal regulations for federal use of the RF spectrum are found in the Manual of Regulations and Procedures for Federal Radio Frequency Management, and extracts of the manual are found in what is known as the Table of Frequency Allocations. Nonfederal government and private sector use of the RF spectrum within the U.S. is regulated by the Federal Communications Commission (FCC). There is a need to control "unwanted emissions" (defined to include out-of-band emissions, which are those immediately adjacent to the necessary and allocated bandwidth, plus spurious emissions) to preclude interference to all other authorized users. This paper discusses the causes, effects, and mitigation of unwanted RF emissions to systems in adjacent spectra. Digital modulations are widely used in today's satellite communications. Commercial communications sector standards are covered for the most part worldwide by Digital Video Broadcast - Satellite (DVB-S) and digital satellite news gathering (DSNG) evolutions and the second generation of DVB-S (DVB-S2) standard

  17. Sinus Congestion

    MedlinePlus

    ... yourself? About Stephen J. Schueler, M.D News Advertising How It Works FAQ for Consumers FAQ for Physicians Testimonials Site Map Terms of Use Contact Us FreeMD is provided for information purposes only and should not be used as a ...

  18. Congestive Hepatomegaly

    MedlinePlus

    ... or out of the liver? Gallstones Gluten intolerance Heart failure High blood pressure Am I Correct? More Videos News HealthDay Better Efforts Could Help Rid the U.S. of Hepatitis B, C: Report TUESDAY, March 28, 2017 (HealthDay News) -- Improved prevention, screening and treatment could ...

  19. Time allocation shifts and pollutant exposure due to traffic congestion: an analysis using the national human activity pattern survey.

    PubMed

    Zhang, Kai; Batterman, Stuart A

    2009-10-15

    Traffic congestion increases air pollutant exposures of commuters and urban populations due to the increased time spent in traffic and the increased vehicular emissions that occur in congestion, especially "stop-and-go" traffic. Increased time in traffic also decreases time in other microenvironments, a trade-off that has not been considered in previous time activity pattern (TAP) analyses conducted for exposure assessment purposes. This research investigates changes in time allocations and exposures that result from traffic congestion. Time shifts were derived using data from the National Human Activity Pattern Survey (NHAPS), which was aggregated to nine microenvironments (six indoor locations, two outdoor locations and one transport location). After imputing missing values, handling outliers, and conducting other quality checks, these data were stratified by respondent age, employment status and period (weekday/weekend). Trade-offs or time-shift coefficients between time spent in vehicles and the eight other microenvironments were then estimated using robust regression. For children and retirees, congestion primarily reduced the time spent at home; for older children and working adults, congestion shifted the time spent at home as well as time in schools, public buildings, and other indoor environments. Changes in benzene and PM(2.5) exposure were estimated for the current average travel delay in the U.S. (9 min day(-1)) and other scenarios using the estimated time shifts coefficients, concentrations in key microenvironments derived from the literature, and a probabilistic analysis. Changes in exposures depended on the duration of the congestion and the pollutant. For example, a 30 min day(-1) travel delay was determined to account for 21+/-12% of current exposure to benzene and 14+/-8% of PM(2.5) exposure. The time allocation shifts and the dynamic approach to TAPs improve estimates of exposure impacts from congestion and other recurring events.

  20. Stroke history and Chagas disease are independent predictors of silent cerebral microembolism in patients with congestive heart failure.

    PubMed

    Jesus, Pedro A P; Neville, Iuri; Cincurá, Carolina; Menezes, Daniela F; Vieira-de-Melo, Rodrigo M; Lacerda, Amanda M; Viana, Leila C; Pereira, Davidson F; Ribeiro-dos-Santos, Valter; Reis, Francisco J F B; Macedo, Cristiano; Oliveira-Filho, Jamary

    2011-01-01

    Chagas disease is endemic in South and Central America, where 18 million individuals are infected by Trypanosoma cruzi, causing congestive heart failure (CHF) and cardioembolic stroke. Transcranial Doppler (TCD) is able to detect real-time microembolic signals (MES) to the brain vessels and may represent a surrogate marker of stroke risk. We aimed to determine predictors of MES in a population of patients with CHF. Consecutive CHF patients from a university-based cardiomyopathy clinic underwent TCD recording of the middle cerebral artery for 60 min by a single investigator who was blinded to all clinical data including cardiomyopathy etiology. Predictors of MES were sought by multivariable logistic regression analysis. From April 2004 to February 2009, 144 patients were studied, including 62 (44.6%) patients with Chagas disease. MES were detected in 9 (6.2%) patients and were more frequent in patients with Chagas disease than in patients with other causes of CHF (12.9 vs. 1.2%, p = 0.005). In multivariate analysis corrected for age and left-ventricular ejection fraction, predictors of MES were Chagas disease (odds ratio = 1.15, 95% confidence interval = 1.05-1.26, p = 0.004) and stroke history (odds ratio = 1.27, 95% confidence interval = 1.08-1.50, p = 0.005). Chagas disease and stroke history are risk factors for MES independent of cardiac disease severity. Other mechanisms besides structural cardiac disease may be operative, increasing embolic risk in Chagas disease. Copyright © 2010 S. Karger AG, Basel.

  1. Transport growth in Bangkok: Energy, environment, and traffic congestion. Workshop proceedings

    SciTech Connect

    Philpott, J.

    1995-07-01

    Bangkok, the capital of Thailand, is a physically and economically complexcity with a complicated transport system. With daily traffic congestion averaging 16 hours, the air quality is such that to breathe street level pollution for 8 eight hours is roughly equivalent to smoking nine cigarettes per day. Estimates suggest idling traffic costs up to $1.6 billion annually. Energy use within the transport sector is on a steady rise with an estimated increase in 11 years of two and one half times. Severe health impacts have begun to effect many residents - young children and the elderly being particularly vulnerable. Bangkok`s air quality and congestion problems are far from hopeless. Great potential exists for Bangkok to remedy its transport-related problems. The city has many necessary characteristics that allow an efficient, economical system of transport. For example, its high density level makes the city a prime candidate for an efficient system of mass transit and the multitude and close proximity of shops, street vendors, restaurants, and residential areas is highly conducive to walking and cycling. Technical knowledge and capacity to devise and implement innovative policies and projects to address air quality and congestion problems is plentiful. There is also consensus among Bangkokians that something needs to be done immediately to clear the air and the roads. However, little has been done. This report proposes a new approach to transport planning for Bangkok that integrates consideration of ecological, social, and financial viability in the process of making decisions regarding managing existing infrastructure and investments in new infrastructure. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  2. The impact of directed choice on the design of preventive healthcare facility network under congestion.

    PubMed

    Vidyarthi, Navneet; Kuzgunkaya, Onur

    2015-12-01

    Preventive healthcare (PH) programs and services aim at reducing the likelihood and severity of potentially life-threatening illness by early detection and prevention. The effectiveness of these programs depends on the participation level and the accessibility of the users to the facilities providing the services. Factors that impact the accessibility include the number, type, and location of the facilities as well as the assignment of the clients to these facilities. In this paper, we study the impact of system-optimal (i.e., directed) choice on the design of the preventive healthcare facility network under congestion. We present a model that simultaneously determines the location and the size of the facilities as well as the allocation of clients to these facilities so as to minimize the weighted sum of the total travel time and the congestion associated with waiting and service delay at the facilities. The problem is set up as a network of spatially distributed M/G/1 queues and formulated as a nonlinear mixed integer program. Using simple transformation of the nonlinear objective function and piecewise linear approximation, we reformulate the problem as a linear model. We present a cutting plane algorithm based exact (-optimal) solution approach. We analyze the tradeoff between travel time and queuing time and its impact on the location and capacity of the facilities as well as the allocation of clients to these facilities under a directed choice policy. We present a case study that deals with locating mammography clinics in Montreal, Canada. The results show that incorporating congestion in the PH facility network design substantially reduces the total time spent by clients. The proposed model allows policy makers to direct clients to facilities in an equitable manner resulting in better accessibility.

  3. Urban emissions hotspots: Quantifying vehicle congestion and air pollution using mobile phone GPS data.

    PubMed

    Gately, Conor K; Hutyra, Lucy R; Peterson, Scott; Sue Wing, Ian

    2017-10-01

    On-road emissions vary widely on time scales as short as minutes and length scales as short as tens of meters. Detailed data on emissions at these scales are a prerequisite to accurately quantifying ambient pollution concentrations and identifying hotspots of human exposure within urban areas. We construct a highly resolved inventory of hourly fluxes of CO, NO2, NOx, PM2.5 and CO2 from road vehicles on 280,000 road segments in eastern Massachusetts for the year 2012. Our inventory integrates a large database of hourly vehicle speeds derived from mobile phone and vehicle GPS data with multiple regional datasets of vehicle flows, fleet characteristics, and local meteorology. We quantify the 'excess' emissions from traffic congestion, finding modest congestion enhancement (3-6%) at regional scales, but hundreds of local hotspots with highly elevated annual emissions (up to 75% for individual roadways in key corridors). Congestion-driven reductions in vehicle fuel economy necessitated 'excess' consumption of 113 million gallons of motor fuel, worth ∼ $415M, but this accounted for only 3.5% of the total fuel consumed in Massachusetts, as over 80% of vehicle travel occurs in uncongested conditions. Across our study domain, emissions are highly spatially concentrated, with 70% of pollution originating from only 10% of the roads. The 2011 EPA National Emissions Inventory (NEI) understates our aggregate emissions of NOx, PM2.5, and CO2 by 46%, 38%, and 18%, respectively. However, CO emissions agree within 5% for the two inventories, suggesting that the large biases in NOx and PM2.5 emissions arise from differences in estimates of diesel vehicle activity. By providing fine-scale information on local emission hotspots and regional emissions patterns, our inventory framework supports targeted traffic interventions, transparent benchmarking, and improvements in overall urban air quality. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Evaluation of public opinion about congestion pricing and tolls. Final research report

    SciTech Connect

    Ulberg, C.; MacFarland, G.

    1995-09-01

    The two primary objectives of the research were (1) to assess public attitudes in the Puget Sound Region toward tolls, congestion pricing, and other forms of market-based transportation pricing (e.g., gas taxes, VMT charges, parking fees) and (2) to explore various ways to present information to the public so that people will feel adequately informaed to decide whether to support pricing system. A third objective that developed out of early research stages was to measure how the level of acceptance of pricing changes (for or against) as understanding increases.

  5. Ethacrynic acid can be effective for refractory congestive heart failure and ascites.

    PubMed

    Alisky, Joseph M; Tuttle, Thomas F

    2003-11-01

    Ethacrynic acid is a loop diuretic little used today because of its side-effect profile and the availability of multiple alternative agents. However, in our clinical experience, ethacrynic acid can alleviate acute congestive heart failure and ascites resistant to other diuretics. Two patients aged 89 and 94 in life-threatening pulmonary edema were stabilized by ethacrynic acid after furosemide proved ineffective. A third patient, aged 83, with a pleural effusion and ascites secondary to end-stage hepatitis B and C, responded to ethacrynic acid when spironolactone and furosemide produced little urine output. Ethacrynic acid may have a unique niche as a diuretic of last resort, especially in geriatric practice.

  6. The aerial relay system: An energy-efficient solution to the airport congestion problem

    NASA Technical Reports Server (NTRS)

    Kyser, A. C.

    1980-01-01

    The ability to transfer airline passengers between aircraft in flight, if adequately developed and integrated into the national air transportation system, could provide significant improvements in transportation-system performance, in terms of airport congestion, fuel consumption, and passenger service. The proposed Aerial Relay System concept, which was developed as a means of exploiting inflight transfer, makes use of large 'cruise liner' aircraft which fly continuously along their routes, docking periodically with short-haul feeder aircraft for exchange of payloads. Preliminary vehicle designs for a representative system are described and the operational feasibility of the concept for the United States in the 1990's is discussed.

  7. Continuity of care prism process applied to the congestive heart failure population.

    PubMed

    Smoot, S M

    1998-01-01

    Emphasis in healthcare during the 1990s has been both to provide optimal wellness and function with quality in a cost-effective manner. The Continuity of Care Prism Process was developed to meet the need to guide clients along the continuum of care and to achieve continuity of care. Advanced practice nurses are the "expert" clinicians in a position to care manage clients and meet the financial and quality constraints currently being placed on healthcare agencies. In this article, the vehicle used to demonstrate the Continuity of Care Prism Process is a congestive heart failure clinical pathway.

  8. A perspective on sympathetic renal denervation in chronic congestive heart failure.

    PubMed

    Madanieh, Raef; El-Hunjul, Mohammed; Alkhawam, Hassan; Kosmas, Constantine E; Madanieh, Abed; Vittorio, Timothy J

    2016-01-01

    Medical therapy has indisputably been the mainstay of management for chronic congestive heart failure. However, a significant percentage of patients continue to experience worsening heart failure (HF) symptoms despite treatment with multiple therapeutic agents. Recently, catheter-based interventional strategies that interrupt the renal sympathetic nervous system have shown promising results in providing better symptom control in patients with HF. In this article, we will review the pathophysiology of HF for better understanding of the interplay between the cardiovascular system and the kidney. Subsequently, we will briefly discuss pivotal renal denervation (RDN) therapy trials in patients with resistant hypertension and then present the available evidence on the role of RDN in HF therapy.

  9. Congestive kidney failure in cardiac surgery: the relationship between central venous pressure and acute kidney injury.

    PubMed

    Gambardella, Ivancarmine; Gaudino, Mario; Ronco, Claudio; Lau, Christopher; Ivascu, Natalia; Girardi, Leonard N

    2016-11-01

    Acute kidney injury (AKI) in cardiac surgery has traditionally been linked to reduced arterial perfusion. There is ongoing evidence that central venous pressure (CVP) has a pivotal role in precipitating acute renal dysfunction in cardiac medical and surgical settings. We can regard this AKI driven by systemic venous hypertension as 'kidney congestive failure'. In the cardiac surgery population as a whole, when the CVP value reaches the threshold of 14 mmHg in postoperative period, the risk of AKI increases 2-fold with an odds ratio (OR) of 1.99, 95% confidence interval (95% CI) of 1.16-3.40. In cardiac surgery subsets where venous hypertension is a hallmark feature, the incidence of AKI is higher (tricuspid disease 30%, carcinoid valve disease 22%). Even in the non-chronically congested coronary artery bypass population, CVP measured 6 h postoperatively showed significant association to renal failure: risk-adjusted OR for AKI was 5.5 (95% CI 1.93-15.5; P = 0.001) with every 5 mmHg rise in CVP for patients with CVP <9 mmHg; for CVP increments of 5 mmHg above the threshold of 9 mmHg, the risk-adjusted OR for AKI was 1.3 (95% CI 1.01-1.65; P = 0.045). This and other clinical evidence are discussed along with the underlying pathophysiological mechanisms, involving the supremacy of volume receptors in regulating the autonomic output in hypervolaemia, and the regional effect of venous congestion on the nephron. The effect of CVP on renal function was found to be modulated by ventricular function class, aetiology and acuity of venous congestion. Evidence suggests that acute increases of CVP should be actively treated to avoid a deterioration of the renal function, particularly in patients with poor ventricular fraction. Besides, the practice of treating right heart failure with fluid loading should be avoided in favour of other ways to optimize haemodynamics in this setting, because of the detrimental effects on the kidney function.

  10. Road Traffic Control Based on Genetic Algorithm for Reducing Traffic Congestion

    NASA Astrophysics Data System (ADS)

    Shigehiro, Yuji; Miyakawa, Takuya; Masuda, Tatsuya

    In this paper, we propose a road traffic control method for reducing traffic congestion with genetic algorithm. In the not too distant future, the system which controls the routes of all vehicles in a certain area must be realized. The system should optimize the routes of all vehicles, however the solution space of this problem is enormous. Therefore we apply the genetic algorithm to this problem, by encoding the route of all vehicles to a fixed length chromosome. To improve the search performance, a new genetic operator called “path shortening” is also designed. The effectiveness of the proposed method is shown by the experiment.

  11. Venus' nighttime horizontal plasma flow, 'magnetic congestion', and ionospheric hole production

    NASA Technical Reports Server (NTRS)

    Grebowsky, J. M.; Mayr, H. G.; Curtis, S. A.; Taylor, H. A., Jr.

    1983-01-01

    A simple rectilinear, two-dimensional MHD model is used to investigate the effects of field-aligned plasma loss and cooling on a dense plasma convecting across a weak magnetic field, in order to illumine the Venus nighttime phenomena of horizontal plasma flow, magnetic congestion and ionospheric hole production. By parameterizing field-aligned variations and explicitly solving for cross magnetic field variations, it is shown that the abrupt horizontal enhancements of the vertical magnetic field, as well as sudden decreases of the plasma density to very low values (which are characteristic of ionospheric holes), can be produced in the presence of field-aligned losses.

  12. Venus' nighttime horizontal plasma flow, 'magnetic congestion', and ionospheric hole production

    NASA Astrophysics Data System (ADS)

    Grebowsky, J. M.; Mayr, H. G.; Curtis, S. A.; Taylor, H. A.

    1983-04-01

    A simple rectilinear, two-dimensional MHD model is used to investigate the effects of field-aligned plasma loss and cooling on a dense plasma convecting across a weak magnetic field, in order to illumine the Venus nighttime phenomena of horizontal plasma flow, magnetic congestion and ionospheric hole production. By parameterizing field-aligned variations and explicitly solving for cross magnetic field variations, it is shown that the abrupt horizontal enhancements of the vertical magnetic field, as well as sudden decreases of the plasma density to very low values (which are characteristic of ionospheric holes), can be produced in the presence of field-aligned losses.

  13. Treatment of feline asthma with ciclosporin in a cat with diabetes mellitus and congestive heart failure.

    PubMed

    Nafe, Laura A; Leach, Stacey B

    2015-12-01

    A 5-year-old domestic shorthair cat that had been previously diagnosed with diabetes mellitus was presented for episodes of coughing and respiratory distress. Diagnostic testing revealed congestive heart failure secondary to hypertrophic cardiomyopathy and concurrent asthma. All clinical signs and eosinophilic airway inflammation resolved with oral ciclosporin while the cat was concurrently receiving medications for treatment of heart failure (furosemide and enalapril). Ciclosporin should be considered for treatment of feline asthma in patients with concurrent diseases (eg, diabetes mellitus, severe heart disease) that may contraindicate use of oral glucocorticoid therapy. © ISFM and AAFP 2014.

  14. The impact of peripheral arterial disease on patients with congestive heart failure.

    PubMed

    Keswani, Amit N; White, Christopher J

    2014-04-01

    Congestive heart failure (CHF) is a prevalent disease with many comorbidities and is associated with high health care expenditures. Peripheral arterial disease (PAD) is a known comorbidity of CHF and is associated with worse morbidity and mortality. CHF and PAD share risk factors, pathophysiology, treatment strategies, and prognostic features. We review the impact of PAD on patients with CHF using several studies to support PAD's influence on outcomes in CHF. Based on the evidence and current guidelines, patients with heart failure who are smokers, and those who have known coronary artery disease and/or diabetes should be screened for PAD.

  15. Heterobilharzia americana infection and congestive heart failure in a llama (Lama glama).

    PubMed

    Corapi, W V; Eden, K B; Edwards, J F; Snowden, K F

    2015-05-01

    The schistosome Heterobilharzia americana infects several mammalian species in the southeastern United States, including horses, but infections have not been reported in camelids. This is a report of H. americana infection in a 6-year-old llama with extensive cardiac pathology and congestive heart failure. Parasite-induced granulomas were widely disseminated and included overwhelming involvement of the lungs and liver. Microscopic lesions in the heart included myofiber degeneration and necrosis, with extensive replacement fibrosis. Polymerase chain reaction amplification and sequencing confirmed the presence of H. americana in the lungs.

  16. Prognostic impact of plasma N-terminal pro-brain natriuretic peptide in severe chronic congestive heart failure: a substudy of the Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS) trial.

    PubMed

    Hartmann, Franz; Packer, Milton; Coats, Andrew J S; Fowler, Michael B; Krum, Henry; Mohacsi, Paul; Rouleau, Jean L; Tendera, Michal; Castaigne, Alain; Anker, Stefan D; Amann-Zalan, Ildiko; Hoersch, Silke; Katus, Hugo A

    2004-09-28

    The utility of N-terminal proBNP (NT-proBNP) to predict the occurrence of death and hospitalization was prospectively evaluated in the COPERNICUS study, which enrolled patients with an ejection fraction <25% and symptoms of chronic congestive heart failure at rest or on minimal exertion. Baseline plasma concentrations of NT-proBNP were measured in a subgroup of 814 men and 197 women with symptoms at rest or on minimal exertion who were enrolled in the COPERNICUS study and were randomized to placebo (n=506) or carvedilol (n=505). Values of NT-proBNP were markedly increased despite the requirement that patients be euvolemic before the start of treatment (mean+/-SD, 3235+/-4392 pg/mL; median, 1767 pg/mL). By univariate Cox regression analysis, NT-proBNP was found to be a powerful predictor of subsequent all-cause mortality (relative risk [RR], 2.7; 95% CI, 1.7 to 4.3; P=0.0001 for above versus below median) and all-cause mortality or hospitalization for heart failure (RR, 2.4; 95% CI, 1.8 to 3.4; P=0.0001 for above versus below median). The predictive value of NT-proBNP was similar when both placebo and carvedilol patients were analyzed separately. No significant interaction was found between NT-proBNP and treatment group (P=0.93 for above- versus below-median NT-proBNP). NT-proBNP was consistently associated with increased risk for all-cause mortality and for all-cause mortality or hospitalization for heart failure in patients with severe congestive heart failure, even in those who were clinically euvolemic. This marker therefore may be a useful tool in risk stratification of patients with severe congestive heart failure.

  17. Random early detection for congestion avoidance in wired networks: a discretized pursuit learning-automata-like solution.

    PubMed

    Misra, Sudip; Oommen, B John; Yanamandra, Sreekeerthy; Obaidat, Mohammad S

    2010-02-01

    In this paper, we present a learning-automata-like The reason why the mechanism is not a pure LA, but rather why it yet mimics one, will be clarified in the body of this paper. (LAL) mechanism for congestion avoidance in wired networks. Our algorithm, named as LAL Random Early Detection (LALRED), is founded on the principles of the operations of existing RED congestion-avoidance mechanisms, augmented with a LAL philosophy. The primary objective of LALRED is to optimize the value of the average size of the queue used for congestion avoidance and to consequently reduce the total loss of packets at the queue. We attempt to achieve this by stationing a LAL algorithm at the gateways and by discretizing the probabilities of the corresponding actions of the congestion-avoidance algorithm. At every time instant, the LAL scheme, in turn, chooses the action that possesses the maximal ratio between the number of times the chosen action is rewarded and the number of times that it has been chosen. In LALRED, we simultaneously increase the likelihood of the scheme converging to the action, which minimizes the number of packet drops at the gateway. Our approach helps to improve the performance of congestion avoidance by adaptively minimizing the queue-loss rate and the average queue size. Simulation results obtained using NS2 establish the improved performance of LALRED over the traditional RED methods which were chosen as the benchmarks for performance comparison purposes.

  18. The Number of Perforators Included in Reversed Flow Posterior Interosseous Artery Flap: Does It Affect the Incidence of Venous Congestion?

    PubMed Central

    Shaker, Ayman A.; Elbarbary, Amir S.; Sayed, Mohamed A.; Elghareeb, Mohamed A.

    2016-01-01

    Background: The purpose of this study is to decrease the incidence of venous congestion occurring in the reversed flow posterior interosseous artery flap used for coverage of hand defects. Methods: This may be achieved by studying the incidence of venous congestion in flaps including only 1 perforator and comparing the results with others including more than 1 perforator both in small and large sized flaps. Results: This study showed that inclusion of only 1 perforator in the flap decreased the incidence of venous congestion with complete flap loss in flaps to 5%. Also, it decreased the incidence of venous congestion with partial flap loss in flaps to 10%. Conclusions: The small sized reversed flow posterior interosseous artery flap should be less than 40 cm2 and should include only 1 perforator to decrease the incidence of venous congestion with partial and complete loss of the flap. The level of evidence for this study is the type II prospective comparative study. PMID:28293513

  19. Dynamic co-expression network analysis of lncRNAs and mRNAs associated with venous congestion

    PubMed Central

    Li, Jinshun; Xu, Yuqin; Xu, Jia; Wang, Jinhua; Wu, Liying

    2016-01-01

    Venous congestion and volume overload are important in cardiorenal syndromes, in which multiple regulated factors are involved, including long non-coding RNAs (lncRNAs). To investigate the underlying role of lncRNAs in regulating the development of venous congestion, an Affymetrix microarray associated with peripheral venous congestion was annotated, then a bipartite dynamic lncRNA-mRNA co-expression network was constructed in which nodes indicated lncRNAs or mRNAs. The nodes were connected when the lncRNAs or mRNAs were dynamically co-expressed. Following functional analysis of this network, several dynamic alternative pathways were identified, including the calcium signaling pathway during venous congestion development. Additionally, certain lncRNAs (LINC00523, LINC01210 and RP11-435O5.5) were identified that may potentially dynamically regulate certain proteins, including plasma membrane calcium ATPase (PMCA) and G protein-coupled receptor (GPCR), in the calcium signaling pathway. Particularly, the dynamically regulated switch of LINC00523 from co-expression with PMCA to GPCR may be involved in damage to steady state intracellular calcium. In brief, the current study demonstrated a potential novel mechanism of lncRNA function during venous congestion. PMID:27431002

  20. Severe ARDS may cause right heart failure with extreme hepatomegaly but without hepatic failure.

    PubMed

    Søreide, E; Harboe, S; Søndenaa, K

    2002-08-01

    A young trauma patient developed severe adult respiratory distress syndrome (ARDS), right heart failure, hepatic congestion and an extreme hepatomegaly but no hepatic failure. The patient needed 100% oxygen during ventilatory support for 80 days and was weaned from the ventilator after more than 100 days. The hepatomegaly gradually disappeared. Four months after the injury, the anatomical shape of the lungs, heart and liver were normalized. This case illustrates that severe ARDS may cause right heart failure and extreme hepatomegaly due to venous congestion in the liver and spleen, but without hepatic failure.

  1. Congestion detection of pedestrians using the velocity entropy: A case study of Love Parade 2010 disaster

    NASA Astrophysics Data System (ADS)

    Huang, Lida; Chen, Tao; Wang, Yan; Yuan, Hongyong

    2015-12-01

    Gatherings of large human crowds often result in crowd disasters such as the Love Parade Disaster in Duisburg, Germany on July 24, 2010. To avoid these tragedies, video surveillance and early warning are becoming more and more significant. In this paper, the velocity entropy is first defined as the criterion for congestion detection, which represents the motion magnitude distribution and the motion direction distribution simultaneously. Then the detection method is verified by the simulation data based on AnyLogic software. To test the generalization performance of this method, video recordings of a real-world case, the Love Parade disaster, are also used in the experiments. The velocity histograms of the foreground object in the videos are extracted by the Gaussian Mixture Model (GMM) and optical flow computation. With a sequential change-point detection algorithm, the velocity entropy can be applied to detect congestions of the Love Parade festival. It turned out that without recognizing and tracking individual pedestrian, our method can detect abnormal crowd behaviors in real-time.

  2. Improving Area Control Error Diversity Interchange (ADI) Program by Incorporating Congestion Constraints

    SciTech Connect

    Zhou, Ning; Etingov, Pavel V.; Makarov, Yuri V.; Guttromson, Ross T.; McManus, Bart

    2010-04-30

    The area control error (ACE) determines how much a balancing authority (BA) needs to move its regulating units to meet mandatory control performance standard requirements. Regulation is an expensive resource that could cost several hundred million dollars a year for a BA. The amount of regulation needed in a system is increasing with more intermittent generation resources added to the system. The ACE diversity interchange (ADI) program provides a tool for reducing the regulation requirement by combining ACEs from several participating BAs followed by sharing the total ACE among all participating balancing areas. The effect is achieved as a result of the low statistical correlation between the original ACEs of participating BAs. A rule-based ADI approach has already been put into practice in the US Western Interconnection. The degree of actual ACE sharing is artificially limited because of the unknown redistribution of power flows and possible system congestion (these factors are not monitored in the existing ADI). This paper proposes a two-step linear programming (LP) ADI approach that incorporates congestion constraints. In the first step of the proposed LP ADI, the line transmission limits are enforced by setting up corresponding constraints. In the second step, the business fairness is pursued. Simulation is performed to compare the properties of the proposed LP ADI and the existing rule-based ADI. Favorable features, such as avoiding line limit violations and increasing the degree of possible ACE sharing, are observed for the proposed LP ADI.

  3. Congestion Prediction Modeling for Quality of Service Improvement in Wireless Sensor Networks

    PubMed Central

    Lee, Ga-Won; Lee, Sung-Young; Huh, Eui-Nam

    2014-01-01

    Information technology (IT) is pushing ahead with drastic reforms of modern life for improvement of human welfare. Objects constitute “Information Networks” through smart, self-regulated information gathering that also recognizes and controls current information states in Wireless Sensor Networks (WSNs). Information observed from sensor networks in real-time is used to increase quality of life (QoL) in various industries and daily life. One of the key challenges of the WSNs is how to achieve lossless data transmission. Although nowadays sensor nodes have enhanced capacities, it is hard to assure lossless and reliable end-to-end data transmission in WSNs due to the unstable wireless links and low hard ware resources to satisfy high quality of service (QoS) requirements. We propose a node and path traffic prediction model to predict and minimize the congestion. This solution includes prediction of packet generation due to network congestion from both periodic and event data generation. Simulation using NS-2 and Matlab is used to demonstrate the effectiveness of the proposed solution. PMID:24784035

  4. Iodine-123 metaiodobenzylguanidine imaging of the heart in idiopathic congestive cardiomyopathy and cardiac transplants

    SciTech Connect

    Glowniak, J.V.; Turner, F.E.; Gray, L.L.; Palac, R.T.; Lagunas-Solar, M.C.; Woodward, W.R.

    1989-07-01

    Iodine-123 metaiodobenzylguanidine ((/sup 123/I)MIBG) is a norepinephrine analog which can be used to image the sympathetic innervation of the heart. In this study, cardiac imaging with (/sup 123/I)MIBG was performed in patients with idiopathic congestive cardiomyopathy and compared to normal controls. Initial uptake, half-time of tracer within the heart, and heart to lung ratios were all significantly reduced in patients compared to normals. Uptake in lungs, liver, salivary glands, and spleen was similar in controls and patients with cardiomyopathy indicating that decreased MIBG uptake was not a generalized abnormality in these patients. Iodine-123 MIBG imaging was also performed in cardiac transplant patients to determine cardiac nonneuronal uptake. Uptake in transplants was less than 10% of normals in the first 2 hr and nearly undetectable after 16 hr. The decreased uptake of MIBG suggests cardiac sympathetic nerve dysfunction while the rapid washout of MIBG from the heart suggests increased cardiac sympathetic nerve activity in idiopathic congestive cardiomyopathy.

  5. SDTCP: Towards Datacenter TCP Congestion Control with SDN for IoT Applications.

    PubMed

    Lu, Yifei; Ling, Zhen; Zhu, Shuhong; Tang, Ling

    2017-01-08

    The Internet of Things (IoT) has gained popularity in recent years. Today's IoT applications are now increasingly deployed in cloud platforms to perform Big Data analytics. In cloud data center networks (DCN), TCP incast usually happens when multiple senders simultaneously communicate with a single receiver. However, when TCP incast happens, DCN may suffer from both throughput collapse for TCP burst flows and temporary starvation for TCP background flows. In this paper, we propose a software defined network (SDN)-based TCP congestion control mechanism, referred to as SDTCP, to leverage the features, e.g., centralized control methods and the global view of the network, in order to solve the TCP incast problems. When we detect network congestion on an OpenFlow switch, our controller can select the background flows and reduce their bandwidth by adjusting the advertised window of TCP ACK packets of the corresponding background flows so as to reserve more bandwidth for burst flows. SDTCP is transparent to the end systems and can accurately decelerate the rate of background flows by leveraging the global view of the network gained via SDN. The experiments demonstrate that our SDTCP can provide high tolerance for burst flows and achieve better flow completion time for short flows. Therefore, SDTCP is an effective and scalable solution for the TCP incast problem.

  6. Congestion Avoidance Control through Non-cooperative Games between Customers and Service Providers

    NASA Astrophysics Data System (ADS)

    Charilas, Dimitris E.; Panagopoulos, Athanasios D.; Vlacheas, Panagiotis; Markaki, Ourania I.; Constantinou, Philip

    Congestion avoidance control refers to controlling the load of the network by restricting the admission of new user’s sessions and resolving the unwanted overload situations. Admission control and Load control constitute key mechanisms regarding Radio Resource Management. As the wireless world is moving towards heterogeneous wireless networks, these types of control are facing more challenges, since efficiency and fairness are required. Game theory provides an appropriate framework for formulating fair and efficient congestion avoidance control problems. In this paper we formulate a non-cooperative game between service providers and customers. On the one hand, the service providers wish to maximize their revenue, but on the other hand, the users wish to maximize the quality of service received, keeping at the same time the expenses as low as possible. Therefore a balance has to be established among these contradictory demands. Our effort also concentrates in the proper modeling of the user’s level of satisfaction, so as to provide a logical decision-taking framework. The proposed scheme is then tested using the ns2 simulator. Results show that both parties can benefit from this mechanism.

  7. TCP fiber: direct measurement optical transport congestion control for beyond 10 gigabit networks

    NASA Astrophysics Data System (ADS)

    Kazantzidis, Matheos

    2006-05-01

    Optical or gigabit communication links could currently allow petabytes of data to be transferred to geographically distributed tera-scale computing facilities at beyond 10Gbps rates. While the bandwidth is available in network link technology, transport protocols like TCP/IP and common network host architectures severely limit the attainable throughput over such links. Traditional layering -that is implemented through excessive per-byte (word) memory bandwidth constrained buffer copying- transport processing complexity, combined error and congestion control and trial and error timeout-based approaches result in prohibitively increasing performance degradation as network speeds increase. In this paper we present TCP-Fiber, a TCP version that is based on direct measurements of available and bottleneck link bandwidth and is able to perform decoupled error and congestion control while supporting zero-copy from application to network interface. A key innovation in TCP-Fiber is a variable length "packet train" based method that allows sensing ultra high bandwidth related quantities in a network independent fashion with relaxed requirements to timers and system resources (as related to interrupts, system calls etc). A TCP-Fiber connection is able to fairly send at the full network rate without extensive trial-and-error convergence procedures or waiting on time-out for unacknowledged packets, while maintaining network stability.

  8. Congestion Control in TCP/AQM Networks Using a Disturbance Observer

    NASA Astrophysics Data System (ADS)

    Kubo, Ryogo; Kani, Junichi; Fujimoto, Yukihiro

    This paper presents a novel congestion controller for transmission control protocol/active queue management (TCP/AQM) networks. In order to maintain the queue length to a value less than the buffer size at the aggregation nodes, the queue management mechanism drops some packets depending on the probability calculated by a congestion controller. However, conventional controllers such as random early detection (RED) algorithms and proportional-integral-derivative (PID)-based controllers are not compatible with parameter variation in TCP/AQM networks. Parameter variation in TCP/AQM networks includes the change of the number of TCP connections, the inflow of user datagram protocol (UDP) flows and so on. In the proposed method, the effect of parameter variation is estimated as drop probability disturbance by using a disturbance observer (DOB). By using the DOB, disturbance suppression characteristics of the controlled system can be drastically improved. In addition, the TCP/AQM network system is analyzed on the basis of an acceleration control scheme. The proposed method is validated by simulation studies performed using a nonlinear model of a TCP/AQM network and verifications made using the network simulator ns-2.

  9. TCP Congestion Control Mechanisms for Achieving Predictable Throughput Using Inline Network Measurement

    NASA Astrophysics Data System (ADS)

    Hasegawa, Go; Yamanegi, Kana; Murata, Masayuki

    Recently, real-time media delivery services such as video streaming and VoIP have rapidly become popular. For these applications requiring high-level QoS guarantee, our research group has proposed a transport-layer approach to provide predictable throughput for upper-layer applications. In the present paper, we propose a congestion control mechanism of TCP for achieving predictable throughput. It does not mean we can guarantee the throughput, while we can provide the throughput required by an upper-layer application at high probability when network congestion level is not so high by using the inline network measurement technique for available bandwidth of the network path. We present the evaluation results for the proposed mechanism obtained in simulation and implementation experiments, and confirm that the proposed mechanism can assure a TCP throughput if the required bandwidth is not so high compared to the physical bandwidth, even when other ordinary TCP (e.g., TCP Reno) connections occupy the link.

  10. A Study on Power Flow Congestion Relief in Cooperation with Customer-side Cogeneration Systems

    NASA Astrophysics Data System (ADS)

    Furusawa, Ken; Yanase, Kazunori; Sugihara, Hideharu; Tsuji, Kiichiro

    Dispersed generation technologies (e.g. Gas-engines) have greatly advanced in recent years. Gas engines are often operated as the main component of a cogeneration system (CGS). By using exhaust heat, the total efficiency of CGSs can reach from 70% to 80%, and as a result, it is also useful for reductions of CO2 emission. Therefore CGSs have been given preferential treatment by the Japanese government and their installation and use is expected to become widespread in the future. As a demand response program, the authors proposed a method whereby CGSs at the customer-side are used for congestion relief in transmission networks. In the proposed method, the optimal configuration of energy systems including CGSs at the customer-side is determined. As well, the optimal operation of the electric utility's generators is also determined taking into account the CGS operation patterns. This paper evaluates both costs to the electric utility and the customers' cost for congestion relief in transmission networks. Further, we evaluate the influence on CO2 emission and primary energy consumption from the view point of a unified energy system with CGSs providing input on a flexible operation pattern.

  11. Readability Assessment of Online Patient Education Material on Congestive Heart Failure

    PubMed Central

    2017-01-01

    Background Online health information is being used more ubiquitously by the general population. However, this information typically favors only a small percentage of readers, which can result in suboptimal medical outcomes for patients. Objective The readability of online patient education materials regarding the topic of congestive heart failure was assessed through six readability assessment tools. Methods The search phrase “congestive heart failure” was employed into the search engine Google. Out of the first 100 websites, only 70 were included attending to compliance with selection and exclusion criteria. These were then assessed through six readability assessment tools. Results Only 5 out of 70 websites were within the limits of the recommended sixth-grade readability level. The mean readability scores were as follows: the Flesch-Kincaid Grade Level (9.79), Gunning-Fog Score (11.95), Coleman-Liau Index (15.17), Simple Measure of Gobbledygook (SMOG) index (11.39), and the Flesch Reading Ease (48.87). Conclusion Most of the analyzed websites were found to be above the sixth-grade readability level recommendations. Efforts need to be made to better tailor online patient education materials to the general population. PMID:28656111

  12. Multifractal properties of ECG patterns of patients suffering from congestive heart failure

    NASA Astrophysics Data System (ADS)

    Dutta, Srimonti

    2010-12-01

    The multifractal properties of two-channel ECG patterns of patients suffering from severe congestive heart failure (New York Heart Association (NYHA) classes III-IV) are studied and are compared with those for normal healthy people using the multifractal detrended fluctuation analysis methodology. Ivanov et al (1999 Nature 399 461) have studied the multifractality of human heart rate dynamics using the wavelet transformation modulus maxima (WTMM) methodology. But it has been observed by several scientists that multifractal detrended fluctuation analysis (MFDFA) works better than the WTMM method in the detection of monofractal and multifractal characteristics of the data. Galaska et al (2008 Ann. Noninvasive Electrocardiol. 13 155) have observed that MFDFA is more sensitive compared to the WTMM method in the differentiation between multifractal properties of the heart rate in healthy subjects and patients with left ventricular systolic dysfunction. In the present work the variation of two parameters of the multifractal spectrum—its width W (related to the degree of multifractality) and the value of the Hölder exponent α0—for the healthy and congestive heart failure patients is studied. α0 is a measure of the degree of correlation. The degree of multifractality varies appreciably (85-90% C.L.) for the normal and the CHF sets for channel I. For channel II no significant change in the values is observed. The degree of correlation is found to be comparatively high for the normal healthy people compared to those suffering from CHF.

  13. Persistent pulmonary congestion before discharge predicts rehospitalization in heart failure: a lung ultrasound study.

    PubMed

    Gargani, Luna; Pang, P S; Frassi, F; Miglioranza, M H; Dini, F L; Landi, P; Picano, E

    2015-09-04

    B-lines evaluated by lung ultrasound (LUS) are the sonographic sign of pulmonary congestion, a major predictor of morbidity and mortality in patients with heart failure (HF). Our aim was to assess the prognostic value of B-lines at discharge to predict rehospitalization at 6 months in patients with acute HF (AHF). A prospective cohort of 100 patients admitted to a Cardiology Department for dyspnea and/or clinical suspicion of AHF were enrolled (mean age 70 ± 11 years). B-lines were evaluated at admission and before discharge. Subjects were followed-up for 6-months after discharge. Mean B-lines at admission was 48 ± 48 with a statistically significant reduction before discharge (20 ± 23, p < .0001). During follow-up, 14 patients were rehospitalized for decompensated HF. The 6-month event-free survival was highest in patients with less B-lines (≤ 15) and lowest in patients with more B-lines (> 15) (log rank χ(2) 20.5, p < .0001). On multivariable analysis, B-lines > 15 before discharge (hazard ratio [HR] 11.74; 95 % confidence interval [CI] 1.30-106.16) was an independent predictor of events at 6 months. Persistent pulmonary congestion before discharge evaluated by ultrasound strongly predicts rehospitalization for HF at 6-months. Absence or a mild degree of B-lines identify a subgroup at extremely low risk to be readmitted for HF decompensation.

  14. [Nursing diagnoses and interventions for patients with congestive heart failure using the ICNP ®].

    PubMed

    de Araújo, Angela Amorim; da Nóbrega, Maria Miriam Lima; Garcia, Telma Ribeiro

    2013-04-01

    The aim of this descriptive exploratory study was to construct nursing diagnosis and intervention statements for patients with Congestive Heart Failure. To accomplish this aim, 53 terms were identified in the focus axis of the International Classification for Nursing Practice (ICNP®), which guided the construction of these statements using the guidelines of the International Council of Nurses and ISO 18. 104. A total of 92 nursing diagnosis statements were constructed, which resulted in 66 statements after standardization. The standardized statements were separated according to the following pathophysiological models: 13 related to tachycardia, 20 related to dyspnea, 19 related to edema, and 14 related to congestion. A total of 234 interventions were constructed for these statements using the terms from the 7-Axis Model of the ICNP®, the literature in the area and the clinical experience of the authors. The nursing diagnosis and intervention statements designed are expected to facilitate the evaluation of CHF patients and assist in the construction of a terminological subset for the ICNP®.

  15. [Renal dysfunction in heart failure and hypervolumenia : Importance of congestion and backward failure].

    PubMed

    Druml, W

    2014-05-01

    Traditionally, renal dysfunction in congestive heart failure (cardiorenal syndrome type 1) has been attributed to reduced cardiac output and low mean arterial perfusion pressure, which elicit a series of neurohumoral activations resulting in increased renal vascular resistance and decreased renal function.During the last decade, several studies have shown that the extent of renal dysfunction is not so closely associated with indices of forward failure-such as the cardiac index or mean arterial pressure-but rather with indicators of congestion, such as left ventricular enddiasystolic pressure or central venous pressure (CVP), which are indicators of backward failure. The impact of backward failure on renal function is not confined to an elevation of CVP, the renal drainage pressure, but includes a broad spectrum of mechanisms. Involved are the organ systems right heart, lung, the liver, the proinflammatory signals originating from the intestines, but also renal interstitial edema (renal compartment syndrome) and the intraabdominal pressure.The therapeutic measures must focus on the modulation of the preload adapted to the specific situation of an individual patient. This includes diuretics aiming at different segments of the tubulus system including antagonists of aldosteron and ADH, extracorporeal fluid elimination by ultrafiltration or peritoneal dialysis.

  16. Robust ?dynamic output feedback control of networked control systems with congestion control

    NASA Astrophysics Data System (ADS)

    Rasool, Faiz; Kiong Ngaung, Sing

    2015-07-01

    This paper investigates a robust ?dynamic output feedback controller for networked control systems (NCSs) with a simple congestion control scheme. This scheme enables the NCSs design to enjoy advantages of both time-triggered and event-triggered systems. The proposed scheme compares current measurement with last transmitted measurement. If difference between them is less than a prescribed percentage of the current measurements then no measurement is transmitted to controller and the controller always uses the last transmitted measurements to calculate feedback gains. Moreover, this technique is applied to controller output as well. The stability criteria for closed-loop system is formulated using the Lyapunov-Krasovskii functional approach. The sufficient conditions for the controller are given in terms of solvability of bilinear matrix inequalities (BMIs). These BMIs are converted into quasi-convex linear matrix inequalities that are solved using the cone complementarity linearisation algorithm. A simulation example is used to evaluate how effective the simple congestion control scheme is in reducing network bandwidth.

  17. Evaluation of the time course of vascular responses to venous congestion in the human lower limb.

    PubMed

    Oldfield, Mark A; Brown, Margaret D

    2006-01-01

    This study examined the time course of changes in blood flow to the lower leg in response to venous distension--the veni-arteriolar vasoconstrictor response--in 31 healthy males. During a 5-min period of venous distension (thigh cuff pressure 50 mm Hg), calf blood flow (venous occlusion plethysmography) decreased more rapidly (within 30 s) compared to skin perfusion (after 2 min, Laser Doppler flowmetry), consistent with disparate filling times of superficial and deeper veins and a greater increase in deep vein volume. On completion of venous filling, vascular resistance in the skin was unchanged from baseline, implying that the reduction in perfusion was solely the result of reduced perfusion pressure. For the whole calf, vascular resistance was unchanged after 1 min but decreased thereafter by 35-45% from baseline, indicating adjustment of pre- or post-capillary resistances to maintain flow. Repeated plethysmographic flow measurements assisted the decrease in resistance, most likely by intermittent compression of the thigh cuff acting to displace blood volume centrally and alleviate congestion. These findings do not support an active veni-arteriolar vasoconstrictor mechanism in response to venous distension alone in the lower leg, and provide evidence of dynamic flow adjustments that should be acknowledged during procedures that involve prolonged periods of venous congestion.

  18. Congestion Control for a Fair Packet Delivery in WSN: From a Complex System Perspective

    PubMed Central

    2014-01-01

    In this work, we propose that packets travelling across a wireless sensor network (WSN) can be seen as the active agents that make up a complex system, just like a bird flock or a fish school, for instance. From this perspective, the tools and models that have been developed to study this kind of systems have been applied. This is in order to create a distributed congestion control based on a set of simple rules programmed at the nodes of the WSN. Our results show that it is possible to adapt the carried traffic to the network capacity, even under stressing conditions. Also, the network performance shows a smooth degradation when the traffic goes beyond a threshold which is settled by the proposed self-organized control. In contrast, without any control, the network collapses before this threshold. The use of the proposed solution provides an effective strategy to address some of the common problems found in WSN deployment by providing a fair packet delivery. In addition, the network congestion is mitigated using adaptive traffic mechanisms based on a satisfaction parameter assessed by each packet which has impact on the global satisfaction of the traffic carried by the WSN. PMID:25177722

  19. Renal replacement therapy in congestive heart failure requiring left ventricular assist device augmentation.

    PubMed

    Thomas, Bernadette A; Logar, Christine M; Anderson, Arthur E

    2012-01-01

    "Cardiorenal syndrome" is a term used to describe a dys-regulation of the heart affecting the kidneys, or vice versa, in an acute or chronic manner (1,2). Renal impairment can range from reversible ischemic damage to renal failure requiring short- or long-term renal replacement therapy (2). Patients who require mechanical circulatory support, such as a left ventricular assist device (LVAD), as definitive treatment for congestive heart failure or as a bridge to cardiac transplantation pose a unique challenge with respect to receiving dialysis, because they experience higher rates of morbidity and mortality from infection in the post-LVAD period (3-7). Acute dialysis access can pose an increased infection risk. In this article, we present a patient who required renal replacement therapy and a LVAD for management of acute-on-chronic cardiorenal syndrome while awaiting heart transplantation. A literature review to determine whether peritoneal dialysis or hemodialysis is superior for patients with profound hemodynamic dysfunction and the need to minimize risk of infection did not offer clear guidance about which modality is superior in patients with advanced congestive heart failure. However, there is clear evidence of the superiority of peritoneal dialysis in reducing the risk of systemic infection secondary to acute dialysis access. Given the high risk of LVAD infection, we therefore conclude that, to decrease mortality secondary to systemic infection, peritoneal dialysis should strongly be considered in patients who require renal replacement therapy before or after LVAD placement.

  20. Nature of the Congested Traffic and Quasi-steady States of the General Motor Models

    NASA Astrophysics Data System (ADS)

    Yang, Bo; Xu, Xihua; Pang, John Z. F.; Monterola, Christopher

    2015-03-01

    We look at the general motor (GM) class microscopic traffic models and analyze some of the universal features of the (multi-)cluster solutions, including the emergence of an intrinsic scale and the quasisoliton dynamics. We show that the GM models can capture the essential physics of the real traffic dynamics, especially the phase transition from the free flow to the congested phase, from which the wide moving jams emerges (the F-S-J transition pioneered by B.S. Kerner). In particular, the congested phase can be associated with either the multi-cluster quasi-steady states, or their more homogeneous precursor states. In both cases the states can last for a long time, and the narrow clusters will eventually grow and merge, leading to the formation of the wide moving jams. We present a general method to fit the empirical parameters so that both quantitative and qualitative macroscopic empirical features can be reproduced with a minimal GM model. We present numerical results for the traffic dynamics both with and without the bottleneck, including various types of spontaneous and induced ``synchronized flow,'' as well as the evolution of wide moving jams. We also discuss its implications to the nature of different phases in traffic dynamics.

  1. Evaluation of TCP Congestion Control Algorithms on the Windows Vista Platform

    SciTech Connect

    Li, Yee-Ting; /SLAC

    2006-07-07

    CTCP, an innovative TCP congestion control algorithm developed by Microsoft, is evaluated and compared to HSTCP and StandardTCP. Tests were performed on the production Internet from Stanford Linear Accelerator Center (SLAC) to various geographically located hosts to give a broad overview of the performances. We find that certain issues were apparent during testing (not directly related to the congestion control algorithms) which may skew results. With this in mind, we find that CTCP performed similarly to HSTCP across a multitude of different network environments. However, to improve the fairness and to reduce the impact of CTCP upon existing StandardTCP traffic, two areas of further research were investigated. Algorithmic additions to CTCP for burst control to reduce the aggressiveness of its cwnd increments demonstrated beneficial improvements in both fairness and throughput over the original CTCP algorithm. Similarly, {gamma} auto-tuning algorithms were investigated to dynamically adapt CTCP flows to their network conditions for optimal performance. While the effects of these auto-tuning algorithms when used in addition to burst control showed little to no benefit to fairness nor throughput for the limited number of network paths tested, one of the auto-tuning algorithms performed such that there was negligible impact upon StandardTCP. With these improvements, CTCP was found to perform better than HSTCP in terms of fairness and similarly in terms of throughput under the production environments tested.

  2. Congestion prediction modeling for quality of service improvement in wireless sensor networks.

    PubMed

    Lee, Ga-Won; Lee, Sung-Young; Huh, Eui-Nam

    2014-04-30

    Information technology (IT) is pushing ahead with drastic reforms of modern life for improvement of human welfare. Objects constitute "Information Networks" through smart, self-regulated information gathering that also recognizes and controls current information states in Wireless Sensor Networks (WSNs). Information observed from sensor networks in real-time is used to increase quality of life (QoL) in various industries and daily life. One of the key challenges of the WSNs is how to achieve lossless data transmission. Although nowadays sensor nodes have enhanced capacities, it is hard to assure lossless and reliable end-to-end data transmission in WSNs due to the unstable wireless links and low hard ware resources to satisfy high quality of service (QoS) requirements. We propose a node and path traffic prediction model to predict and minimize the congestion. This solution includes prediction of packet generation due to network congestion from both periodic and event data generation. Simulation using NS-2 and Matlab is used to demonstrate the effectiveness of the proposed solution.

  3. Congestion control for a fair packet delivery in WSN: from a complex system perspective.

    PubMed

    Aguirre-Guerrero, Daniela; Marcelín-Jiménez, Ricardo; Rodriguez-Colina, Enrique; Pascoe-Chalke, Michael

    2014-01-01

    In this work, we propose that packets travelling across a wireless sensor network (WSN) can be seen as the active agents that make up a complex system, just like a bird flock or a fish school, for instance. From this perspective, the tools and models that have been developed to study this kind of systems have been applied. This is in order to create a distributed congestion control based on a set of simple rules programmed at the nodes of the WSN. Our results show that it is possible to adapt the carried traffic to the network capacity, even under stressing conditions. Also, the network performance shows a smooth degradation when the traffic goes beyond a threshold which is settled by the proposed self-organized control. In contrast, without any control, the network collapses before this threshold. The use of the proposed solution provides an effective strategy to address some of the common problems found in WSN deployment by providing a fair packet delivery. In addition, the network congestion is mitigated using adaptive traffic mechanisms based on a satisfaction parameter assessed by each packet which has impact on the global satisfaction of the traffic carried by the WSN.

  4. Design and Implementation of Real-Time Vehicular Camera for Driver Assistance and Traffic Congestion Estimation.

    PubMed

    Son, Sanghyun; Baek, Yunju

    2015-08-18

    As society has developed, the number of vehicles has increased and road conditions have become complicated, increasing the risk of crashes. Therefore, a service that provides safe vehicle control and various types of information to the driver is urgently needed. In this study, we designed and implemented a real-time traffic information system and a smart camera device for smart driver assistance systems. We selected a commercial device for the smart driver assistance systems, and applied a computer vision algorithm to perform image recognition. For application to the dynamic region of interest, dynamic frame skip methods were implemented to perform parallel processing in order to enable real-time operation. In addition, we designed and implemented a model to estimate congestion by analyzing traffic information. The performance of the proposed method was evaluated using images of a real road environment. We found that the processing time improved by 15.4 times when all the proposed methods were applied in the application. Further, we found experimentally that there was little or no change in the recognition accuracy when the proposed method was applied. Using the traffic congestion estimation model, we also found that the average error rate of the proposed model was 5.3%.

  5. Design and Implementation of Real-Time Vehicular Camera for Driver Assistance and Traffic Congestion Estimation

    PubMed Central

    Son, Sanghyun; Baek, Yunju

    2015-01-01

    As society has developed, the number of vehicles has increased and road conditions have become complicated, increasing the risk of crashes. Therefore, a service that provides safe vehicle control and various types of information to the driver is urgently needed. In this study, we designed and implemented a real-time traffic information system and a smart camera device for smart driver assistance systems. We selected a commercial device for the smart driver assistance systems, and applied a computer vision algorithm to perform image recognition. For application to the dynamic region of interest, dynamic frame skip methods were implemented to perform parallel processing in order to enable real-time operation. In addition, we designed and implemented a model to estimate congestion by analyzing traffic information. The performance of the proposed method was evaluated using images of a real road environment. We found that the processing time improved by 15.4 times when all the proposed methods were applied in the application. Further, we found experimentally that there was little or no change in the recognition accuracy when the proposed method was applied. Using the traffic congestion estimation model, we also found that the average error rate of the proposed model was 5.3%. PMID:26295230

  6. SDTCP: Towards Datacenter TCP Congestion Control with SDN for IoT Applications

    PubMed Central

    Lu, Yifei; Ling, Zhen; Zhu, Shuhong; Tang, Ling

    2017-01-01

    The Internet of Things (IoT) has gained popularity in recent years. Today’s IoT applications are now increasingly deployed in cloud platforms to perform Big Data analytics. In cloud data center networks (DCN), TCP incast usually happens when multiple senders simultaneously communicate with a single receiver. However, when TCP incast happens, DCN may suffer from both throughput collapse for TCP burst flows and temporary starvation for TCP background flows. In this paper, we propose a software defined network (SDN)-based TCP congestion control mechanism, referred to as SDTCP, to leverage the features, e.g., centralized control methods and the global view of the network, in order to solve the TCP incast problems. When we detect network congestion on an OpenFlow switch, our controller can select the background flows and reduce their bandwidth by adjusting the advertised window of TCP ACK packets of the corresponding background flows so as to reserve more bandwidth for burst flows. SDTCP is transparent to the end systems and can accurately decelerate the rate of background flows by leveraging the global view of the network gained via SDN. The experiments demonstrate that our SDTCP can provide high tolerance for burst flows and achieve better flow completion time for short flows. Therefore, SDTCP is an effective and scalable solution for the TCP incast problem. PMID:28075347

  7. Decoupling congestion control and error control mechanisms in TCP and evaluating their performance over broadband satellite networks

    NASA Astrophysics Data System (ADS)

    Wang, Lina; Gu, Xuemai

    2004-04-01

    In this paper, we propose a novel method to better evaluate the performance of TCP over broadband satellite networks. We decouple the most crucial parts of TCP that impact its performance in broadband satellite environments, namely congestion control and error control mechanisms. And then we re-design these two function blocks and make them become two individual parts. With these re-designed modules, we have investigated the interactions between various currently existing TCP congestion control and error control schemes, as well as their impact on TCP performance over a geostationary broadband satellite link with long propagation delay and high bit error rate. Simulation results have shown that some combinations of different congestion control and error control mechanisms can waste satellite link bandwidth with large numbers of retransmission packets and unnecessary retransmission packets. And the modified TCP NewReno implementation can avoid high amount of retransmissions and unnecessary retransmissions.

  8. Reducing Traffic Congestions by Introducing CACC-Vehicles on a Multi-Lane Highway Using Agent-Based Approach

    NASA Technical Reports Server (NTRS)

    Arnaout, Georges M.; Bowling, Shannon R.

    2011-01-01

    Traffic congestion is an ongoing problem of great interest to researchers from different areas in academia. With the emerging technology for inter-vehicle communication, vehicles have the ability to exchange information with predecessors by wireless communication. In this paper, we present an agent-based model of traffic congestion and examine the impact of having CACC (Cooperative Adaptive Cruise Control) embedded vehicle(s) on a highway system consisting of 4 traffic lanes without overtaking. In our model, CACC vehicles adapt their acceleration/deceleration according to vehicle-to-vehicle inter-communication. We analyze the average speed of the cars, the shockwaves, and the evolution of traffic congestion throughout the lifecycle of the model. The study identifies how CACC vehicles affect the dynamics of traffic flow on a complex network and reduce the oscillatory behavior (stop and go) resulting from the acceleration/deceleration of the vehicles.

  9. Extracellular Superoxide Dismutase Ameliorates Skeletal Muscle Abnormalities, Cachexia and Exercise Intolerance in Mice with Congestive Heart Failure

    PubMed Central

    Okutsu, Mitsuharu; Call, Jarrod A.; Lira, Vitor A.; Zhang, Mei; Donet, Jean A.; French, Brent A.; Martin, Kyle S.; Peirce-Cottler, Shayn M.; Rembold, Christopher M.; Annex, Brian H.; Yan, Zhen

    2014-01-01

    Background Congestive heart failure (CHF) is a leading cause of morbidity and mortality, and oxidative stress has been implicated in the pathogenesis of cachexia (muscle wasting) and the hallmark symptom, exercise intolerance. We have previously shown that a nitric oxide (NO)-dependent antioxidant defense renders oxidative skeletal muscle resistant to catabolic wasting. Here, we aimed to identify and determine the functional role of the NO-inducible antioxidant enzyme(s) in protection against cardiac cachexia and exercise intolerance in CHF. Methods and Results We demonstrated that systemic administration of endogenous nitric oxide donor S-Nitrosoglutathione in mice blocked the reduction of extracellular superoxide dismutase (EcSOD) protein expression, the induction of MAFbx/Atrogin-1 mRNA expression and muscle atrophy induced by glucocorticoid. We further showed that endogenous EcSOD, expressed primarily by type IId/x and IIa myofibers and enriched at endothelial cells, is induced by exercise training. Muscle-specific overexpression of EcSOD by somatic gene transfer or transgenesis [muscle creatine kinase (MCK)-EcSOD] in mice significantly attenuated muscle atrophy. Importantly, when crossbred into a mouse genetic model of CHF [α-myosin heavy chain (MHC)-calsequestrin] MCK-EcSOD transgenic mice had significant attenuation of cachexia with preserved whole body muscle strength and endurance capacity in the absence of reduced heart failure. Enhanced EcSOD expression significantly ameliorated CHF-induced oxidative stress, MAFbx/Atrogin-1 mRNA expression, loss of mitochondria and vascular rarefaction in skeletal muscle. Conclusions EcSOD plays an important antioxidant defense function in skeletal muscle against cardiac cachexia and exercise intolerance in CHF. PMID:24523418

  10. [Effects of hot water bath or sauna on patients with congestive heart failure: acute hemodynamic improvement by thermal vasodilation].

    PubMed

    Tei, C; Horikiri, Y; Park, J C; Jeong, J W; Chang, K S; Tanaka, N; Toyama, Y

    1994-01-01

    The acute hemodynamic effects of thermal vasodilation caused by exposure to hot water bath or sauna in chronic congestive heart failure were investigated in 32 patients (mean age 57 +/- 15 years old) with dilated cardiomyopathy (25 idiopathic and 7 ischemic). The clinical symptoms were New York Heart Association Class II in 2 patients, III in 17 and IV in 13, and the mean ejection fraction was 25 +/- 9% (9-44%). Exposure to hot water bath was for 10 minutes at 41 degrees C in a semi-sitting position, and to sauna for 15 minutes at 60 degrees C in a supine position using a special far infrared ray sauna chamber. Blood pressure, electrocardiogram, two-dimensional and Doppler echocardiograms, expiration gas, and intracardiac pressure tracings were recorded before (control), during, and 30 minutes after hot water bath or sauna. 1. The increase in oxygen consumption was only 0.3 Mets during hot water bath or sauna, and returned to the control level 30 minutes later. 2. The deep temperature in the main pulmonary artery increased by 1.0-1.2 degrees C on average at the end of hot water bath or sauna. 3. Heart rate increased significantly (p < 0.01) by 20-25/min during bathing and still increased 30 min later. 4. Systolic blood pressure did not change significantly during and after hot water bath or sauna, while, diastolic blood pressure decreased significantly during (p < 0.05) and after sauna (p < 0.01), and after hot water bath (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Effects and safety of oral tolvaptan in patients with congestive heart failure: A systematic review and network meta-analysis.

    PubMed

    Wu, Mei-Yi; Chen, Tzu-Ting; Chen, Ying-Chun; Tarng, Der-Cherng; Wu, Yun-Chun; Lin, Hsien-Ho; Tu, Yu-Kang

    2017-01-01

    Several studies reported treatment benefits of tolvaptan in patients with congestive heart failure (CHF). However, the optimal dosage remains unclear. We aimed to compare different dosage of tolvaptan to determine the optimal dosage in terms of the efficacy and safety. We searched MEDLINE, PubMed, EMBASE, Cochrane CENTRAL and ClinicalTrials.gov through Aug 31, 2016. Randomized controlled trials (RCTs) comparing tolvaptan of different dosages or to placebo in patients with CHF were included. We used network meta-analysis to look for the optimal dosage in terms of effectiveness and safety. Urine output, body weight change and change in serum sodium were the main outcomes of efficacy. Adverse effects were the secondary outcomes. Quality was assessed by Cochrane risk-of-bias tool. Twelve RCTs reporting 14 articles with 5793 patients (mean age, 65.7 ± 11.9 years; 73.7% man) were included. Compared with placebo, the tolvaptan 30 mg had similar effects to tolvaptan 45-90 mg in terms of urine output (mean difference [MD] 2.03 liter; 95% confidence interval [CI] 1.3 to 2.71), body weight change (MD -1.12 kg; 95% CI -1.37 to -0.88) and change in serum sodium (MD 3.06 meq/L; 95% CI 2.43 to 3.68). Compared with placebo, tolvaptan of different dosage showed a non-significant higher risk of adverse effects. These findings suggest that tolvaptan 30 mg and 45 mg may be the optimum dosage for CHF patients, because of its ability to provide favourable clinical results without greater adverse effects. However, tolvaptan is not beneficial for reducing all-cause mortality in CHF patients.

  12. Policy expectations and reality of telemedicine - a critical analysis of health care outcomes, costs and acceptance for congestive heart failure.

    PubMed

    Achelrod, Dmitrij

    2014-06-01

    A critical review of evidence was carried out to discover whether the actual performance of telemedicine fulfils the expectations of German policy-makers. The analysis was conducted using the example of telemedicine for congestive heart failure (CHF). It was based on both German and international evidence. The PubMed, MEDLINE, Google Scholar and Cochrane Library databases were searched, as well as public sources from the German Federal Ministry of Health. Forty-five studies reporting patient outcomes, costs or acceptance of telemedicine for CHF were included in the review, of which 28 were interventional. The policy expectations of telemedicine generally are: high technology acceptance and improved patient outcomes at lower costs. However, in the field of CHF, policy-makers underestimate the complexity of telemedicine and the technology has not yet lived up to its expectations. Although some studies show improvements in all-cause mortality and CHF-related hospitalisations, there is excessive study heterogeneity and vagueness in the areas of costs and acceptance. Methodological insufficiencies as well as the scarcity of evidence in the German context do not allow definite conclusions to be drawn. Policy-makers and other stakeholders should increase their efforts to consolidate isolated telemedicine projects, establish guidelines for clinical treatment procedures and economic evaluations, and define industry/technical device standards to enhance the comparability of interventions. Imposing the use of telemedicine on patients and physicians is not likely to be fruitful. A successful adaptation requires an analysis of needs and continuous education on both sides. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  13. Reducing the cost of frequent hospital admissions for congestive heart failure: a randomized trial of a home telecare intervention.

    PubMed

    Jerant, A F; Azari, R; Nesbitt, T S

    2001-11-01

    The high cost of caring for patients with congestive heart failure (CHF) results primarily from frequent hospital readmissions for exacerbations. Home nurse visits after discharge can reduce readmissions, but the intervention costs are high. To compare the effectiveness of three hospital discharge care models for reducing CHF-related readmission charges: 1) home telecare delivered via a 2-way video-conference device with an integrated electronic stethoscope; 2) nurse telephone calls; and 3) usual outpatient care. One-year randomized trial. English-speaking patients 40 years of age and older with a primary hospital admission diagnosis of CHF. Our primary outcome was CHF-related readmission charges during a 6-month period after randomization. Secondary outcomes included all-cause readmissions, emergency department (ED) visits, and associated charges. Thirty-seven subjects were randomized: 13 to home telecare, 12 each telephone care and 12 to usual care. Mean CHF-related readmission charges were 86% lower in the telecare group ($5850, SD $21,094) and 84% lower in the telephone group ($7320, SD $24,440) than in the usual care group ($44,479, SD $121,214). However, the between-group difference was not statistically significant. Both intervention groups had significantly fewer CHF-related ED visits (P = 0.0342) and charges (P = 0.0487) than the usual care group. Trends favoring both interventions were noted for all other utilization outcomes. Substantial reductions in hospital readmissions, emergency visits, and cost of care for patients with CHF might be achieved by widespread deployment of distance technologies to provide posthospitalization monitoring. Home telecare may not offer incremental benefit beyond telephone follow-up and is more expensive.

  14. Determining gaseous emission factors and driver's particle exposures during traffic congestion by vehicle-following measurement techniques.

    PubMed

    Tang, U Wa; Wang, Zhishi

    2006-11-01

    Vehicle gaseous emissions (NO, CO, CO2, and hydrocarbon [HC]) and driver's particle exposures (particulate matter < 1 microm [PM1], < 2.5 microm [PM2.5], and < 10 microm [PM10]) were measured using a mobile laboratory to follow a wide variety of vehicles during very heavy traffic congestion in Macao, Special Administrative Region, People's Republic of China, an urban area having one of the highest population densities in the world. The measurements were taken with high time resolution so that fluctuations in the emissions can be seen readily during vehicle acceleration, cruising, deceleration, and idling. The tests were conducted in close proximity to the vehicles, with the inlet of a five-gas analyzer mounted on the front bumper of the mobile laboratory, and the distance between the vehicles was usually within several meters. To measure the driver's particle exposures, the inlets of the particle analyzers were mounted at the height of the driver's breathing position in the mobile laboratory, with the driver's window open. A total of 178 and 113 vehicles were followed individually to determine the gaseous emission factor and the driver's particle exposures, respectively, for motorcycle, passenger car, taxi, truck, and bus. The gaseous emission factors were used to model the roadside air quality, and good correlations between the modeled and monitored CO, NO2, and nitrogen oxide (NO(x)) verified the reliability of the experiments. Compared with petrol passenger cars and petrol trucks, diesel taxies and diesel trucks emitted less CO but more NO(x). The impact of urban canyons is shown to cause a significant increase in the PM1 peak. The background concentrations contributed a significant amount of the driver's particle exposures.

  15. The kidney in congestive heart failure: 'are natriuresis, sodium, and diuretics really the good, the bad and the ugly?'.

    PubMed

    Verbrugge, Frederik H; Dupont, Matthias; Steels, Paul; Grieten, Lars; Swennen, Quirine; Tang, W H Wilson; Mullens, Wilfried

    2014-02-01

    This review discusses renal sodium handling in heart failure. Increased sodium avidity and tendency to extracellular volume overload, i.e. congestion, are hallmark features of the heart failure syndrome. Particularly in the case of concomitant renal dysfunction, the kidneys often fail to elicit potent natriuresis. Yet, assessment of renal function is generally performed by measuring serum creatinine, which has inherent limitations as a biomarker for the glomerular filtration rate (GFR). Moreover, glomerular filtration only represents part of the nephron's function. Alterations in the fractional reabsorptive rate of sodium are at least equally important in emerging therapy-refractory congestion. Indeed, renal blood flow decreases before the GFR is affected in congestive heart failure. The resulting increased filtration fraction changes Starling forces in peritubular capillaries, which drive sodium reabsorption in the proximal tubules. Congestion further stimulates this process by augmenting renal lymph flow. Consequently, fractional sodium reabsorption in the proximal tubules is significantly increased, limiting sodium delivery to the distal nephron. Orthosympathetic activation probably plays a pivotal role in those deranged intrarenal haemodynamics, which ultimately enhance diuretic resistance, stimulate neurohumoral activation with aldosterone breakthrough, and compromise the counter-regulatory function of natriuretic peptides. Recent evidence even suggests that intrinsic renal derangements might impair natriuresis early on, before clinical congestion or neurohumoral activation are evident. This represents a paradigm shift in heart failure pathophysiology, as it suggests that renal dysfunction-although not by conventional GFR measurements-is driving disease progression. In this respect, a better understanding of renal sodium handling in congestive heart failure is crucial to achieve more tailored decongestive therapy, while preserving renal function.

  16. Use of intranasal corticosteroids in the management of congestion and sleep disturbance in pediatric patients with allergic rhinitis.

    PubMed

    Lanier, Bob Q

    2008-06-01

    Allergic rhinitis affects a large number of children and exerts a considerable socioeconomic impact. It is underdiagnosed and inadequately treated, which predisposes children to potentially serious comorbidities. Allergic rhinitis symptoms may create nighttime breathing problems and sleep disturbances and have a negative effect on a child's ability to learn in the classroom. Although antihistamines have shown efficacy in relieving many symptoms, they have little effect on nasal congestion. This article summarizes the advantages of intranasal corticosteroids, including their effectiveness against congestion and excellent safety profile. Intranasal corticosteroids with minimal systemic bioavailability provide topical drug delivery that minimizes the potential for systemic side-effects.

  17. Pacing mode and long-term survival in elderly patients with congestive heart failure: 1980-1985.

    PubMed

    Brady, P A; Shen, W K; Neubauer, S A; Hammill, S C; Hodge, D O; Hayes, D L

    1997-11-01

    Dual-chamber pacing may improve short-term hemodynamics and functional class in some patients with congestive heart failure, even in the absence of conventional indications for pacemaker implantation. However, the impact of different pacing modes on survival of patients with congestive heart failure is controversial. In this retrospective study we analyzed survival data from 546 elderly patients, aged 70 years and older, who underwent implantation of a permanent dual-chamber (DDD, n = 62, DVI, n = 102) or single-chamber (VVI) pacemaker (n = 382) between 1980 and 1985. Survival was further analyzed according to the presence of absence of congestive heart failure, and pacemaker mode (DDD vs. DVI vs. VVI). Overall, dual-chamber pacing (DDD and DVI) was associated with a more favorable long-term outcome when compared with single-chamber ventricular pacing, although differences were only significant for DDD pacing (P = 0.002). When patients with and without preexisting congestive heart failure were analyzed separately, survival following dual-chamber pacing (DDD and DVI) was significantly better than survival following single-chamber pacing in patients without congestive heart failure (P = 0.03), but not in patients with preexisting heart failure (P = 0.139). When patients were analyzed according to the electrophysiological indication for pacemaker implantation, overall survival of patients with AV block (P = 0.0025) but not sinus node dysfunction (P = 0.346) was improved with dual-chamber pacing. This survival advantage in patients with AV block following dual-chamber pacing was lost in the presence of heart failure (P = 0.11). These findings suggest that dual-chamber pacing, in particular DDD pacing, improves the survival in elderly patients without preexisting congestive heart failure. In contrast to the short-term hemodynamic improvement observed in selected patients with congestive heart failure, dual-chamber pacing in elderly patients with congestive heart failure

  18. Assessment of vasodilator therapy in patients with severe congestive heart failure: limitations of measurements of left ventricular ejection fraction and volumes

    SciTech Connect

    Firth, B.G.; Dehmer, G.J.; Markham, R.V. Jr.; Willerson, J.T.; Hillis, L.D.

    1982-11-01

    Although noninvasive techniques are often used to assess the effect of vasodilator therapy in patients with congestive heart failure, it is unknown whether changes in noninvasively determined left ventricular ejection fraction, volume, or dimension reliably reflect alterations in intracardiac pressure and flow. Accordingly, we compared the acute effect of sodium nitroprusside on left ventricular volume and ejection fraction (determined scintigraphically) with its effect on intracardiac pressure and forward cardiac index (determined by thermodilution) in 12 patients with severe, chronic congestive heart failure and a markedly dilated left ventricle. Nitroprusside (infused at 1.3 +/- 1.1 (mean +/- standard deviation) microgram/kg/min) caused a decrease in mean systemic arterial, mean pulmonary arterial, and mean pulmonary capillary wedge pressure as well as a concomitant increase in forward cardiac index. Simultaneously, left ventricular end-diastolic and end-systolic volume indexes decreased, but the scintigraphically determined cardiac index did not change significantly. Left ventricular ejection fraction averaged 0.19 +/- 0.05 before nitroprusside administration and increased by less than 0.05 units in response to nitroprusside in 11 of 12 patients. The only significant correlation between scintigraphically and invasively determined variables was that between the percent change in end-diastolic volume index and the percent change in pulmonary capillary wedge pressure (r . 0.68, p . 0.01). Although nitroprusside produced changes in scintigraphically determined left ventricular ejection fraction, end-systolic volume index, and cardiac index, these alterations bore no predictable relation to changes in intracardiac pressure, forward cardiac index, or vascular resistance. Furthermore, nitroprusside produced a considerably greater percent change in the invasively measured variables than in the scintigraphically determined ones.

  19. Pharmacogenetic Risk Stratification in Angiotensin-Converting Enzyme Inhibitor-Treated Patients with Congestive Heart Failure: A Retrospective Cohort Study

    PubMed Central

    Nelveg-Kristensen, Karl Emil; Busk Madsen, Majbritt; Torp-Pedersen, Christian; Køber, Lars; Egfjord, Martin; Berg Rasmussen, Henrik; Riis Hansen, Peter

    2015-01-01

    Background Evidence for pharmacogenetic risk stratification of angiotensin-converting enzyme inhibitor (ACEI) treatment is limited. Therefore, in a cohort of ACEI-treated patients with congestive heart failure (CHF), we investigated the predictive value of two pharmacogenetic scores that previously were found to predict ACEI efficacy in patients with ischemic heart disease and hypertension, respectively. Score A combined single nucleotide polymorphisms (SNPs) of the angiotensin II receptor type 1 gene (rs275651 and rs5182) and the bradykinin receptor B1 gene (rs12050217). Score B combined SNPs of the angiotensin-converting enzyme gene (rs4343) and ABO blood group genes (rs495828 and rs8176746). Methods Danish patients with CHF enrolled in the previously reported Echocardiography and Heart Outcome Study were included. Subjects were genotyped and categorized according to pharmacogenetic scores A and B of ≤1, 2 and ≥3 each, and followed for up to 10 years. Difference in cumulative incidences of cardiovascular death and all-cause death were assessed by the cumulative incidence estimator. Survival was modeled by Cox proportional hazard analyses. Results We included 667 patients, of whom 80% were treated with ACEIs. Differences in cumulative incidences of cardiovascular death (P = 0.346 and P = 0.486) and all-cause death (P = 0.515 and P = 0.486) were not significant for score A and B, respectively. There was no difference in risk of cardiovascular death or all-cause death between subjects with score A ≤1 vs. 2 (HR 1.03 [95% CI 0.79–1.34] and HR 1.11 [95% CI 0.88–1.42]), score A ≤1 vs. ≥3 (HR 0.80 [95% CI 0.59–1.08] and HR 0.91 [95% CI 0.70–1.20]), score B ≤1 vs. 2 (HR 1.02 [95% CI 0.78–1.32] and HR 0.98 [95% CI 0.77–1.24]), and score B ≤1 vs. ≥3 (HR 1.03 [95% CI 0.75–1.41] and HR 1.05 [95% CI 0.79–1.40]), respectively. Conclusions We found no association between either of the analyzed pharmacogenetic scores and fatal outcomes in ACEI

  20. Splenic autotransplantation for a congested and enlarged wandering spleen with torsion: report of a case.

    PubMed

    Takayasu, Hajime; Ishimaru, Yuki; Tahara, Kazunori; Otani, Yushi; Yamagishi, Junko; Ikeda, Hitoshi

    2006-01-01

    In children with diseases of the spleen, every effort should be made to preserve the organ, to prevent severe infections postsplenectomy. We report the case of a 7-year-old girl with torsion of a wandering spleen who we treated by autotransplantation of splenic tissues following splenectomy, when fixation of the enlarged spleen seemed impossible. Spleen scintigraphy showed uptake in the regenerating splenic tissues 9 months after surgery, and evidence of an increase in the size of the tissues 23 months after surgery. Howell-Jolly bodies had disappeared by 16 months after surgery. These findings suggested that the transplanted splenic tissues were resuming splenic functions. Based on our experience with this case, we conclude that autotransplantation after splenectomy is a treatment option for wandering spleen with torsion when fixation seems difficult because of splenic congestion and enlargement.